High value product (HVP) production methods using raceway pond systems

Abstract

The present invention relates to methods for producing high value products (HVPs) by culturing algae in land-based mariculture using a 'hurry up and wait' approach to algal cultivation, in which growth rates are maximised upstream for maximum throughput and decreased quickly via intensive stressing before harvest. The invention also relates to a 'split pond' approach, in which the pond train becomes non-linear to facilitate the 'hurry up and wait' approach, with a maximal increase in light stress pre-harvest.

Description

[0001] HIGH VALUE PRODUCT (HVP) PRODUCTION METHODS USING RACEWAY POND SYSTEMSAll documents cited herein are incorporated by reference in their entirety. TECHNICAL FIELDThe present invention relates to methods for producing high value products (HVPs) by culturing algaein land-based mariculture. BACKGROUND Under a stressed, sub-, or supra-optimal growth condition, microalgae will continue to photosynthesize and produce storage products in preparation for lean times, hibernating in sediments or transitioning to the next growth season. The algae are still alive when they produce these storageproducts, but their growth rate is significantly reduced. For example, if nitrogen is limited, the cellscannot synthesize the proteins necessary for growth, and the carbon which would usually be fixedthrough photosynthesis (at lower rates) can still be stored in lipids or carbohydrates. This is a transitional state and is distinct from cyst formation and other forms of long-term dormancy. The products produced by the microalgae in these states can be of considerable commercial value.Microalgal cultivation for specific products can be structurally embedded in an open, raceway, pond-system design. The sequence of ponds can enable the switch between multiple growth modes orphysiological states that result in the switch from fast / exponential growth into, for example, cyst,storage product or photoprotectant formation. In turn, this switch in growth state is associated with theproduction of various HVPs. There is a need for more efficient methods for producing high quality HVPs, including proteins, lipids, carbohydrates, pigments and bioavailable minerals. SUMMARY OF THE INVENTION The invention relates to a production system based on culturing algae in raceway ponds to create a very high-throughput, highly scalable and highly sustainable high value product (HVP) production system. The inventors’ methods involve a ‘hurry up and wait’ approach to algal cultivation, in which growthrates are maximised upstream for maximum throughput and decreased quickly via intensive stressingbefore harvest. In some instances, a ‘split pond’ approach is deployed, in which the pond train becomes non-linear to facilitate the ‘hurry up and wait’ approach, with a maximal increase in lightstress pre-harvest. In some instances, a “clustering” approach is implemented, where the harvestponds are grouped and harvested in a staggered manner, which prevents a harvesting bottleneck, reduces harvesting demands and results in a more cost-effective method. The high-throughput algal culture system comprises two principal phases. In the first phase, algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition. The algae typically contain low levels of HVP during this phase. In the second phase, the cultivation conditions are adjusted to deliberately induce the formation of HVP, typically by stressing the cells through one or more of nutrient limitation, high salinity, high temperature, low temperature,increasing light exposure, decreasing light exposure, and increasing the ratio of orange to blue light.The ‘in-sequence’ switch from maximizing growth to maximizing HVP content at the end of aconnected series of raceway ponds results in highly efficient HVP production.Pigments are examples of HVPs, and carotenoids are an example of this class of compounds.Carotenoid extraction directly from fresh, wet biomass (such as an algal slurry) contributes to theoverall objective of producing carotenoids in an environmentally friendly and cost-effective way. Inparticular, carotenoid extraction from wet biomass avoids the need for an energy-intensive drying step which would result in detrimental effects on the environment and increased production costs. The present application shows that carotenoid extraction from algae is possible without such a drying step. Furthermore, carotenoid extraction from wet biomass is more efficient than extraction from dry biomass. In some instances, the inventors’ methods combine: (1) high-throughput algal culture, (2) high-throughput harvesting to result in a live slurry of concentrated algal cells, (3) HVP extraction from fresh wet biomass and (4) purification and separation of HVPs with minimal processing steps. The inventors have provided guidance on methods for culturing algae in United Kingdom PatentApplication Nos.2207837.2, 2303156.0, 2212805.2, 2308480.9, 2212809.4 and 2308479.1, as wellas International Patent Application Nos. PCT / GB2023 / 051392, PCT / GB2023 / 052278 andPCT / GB2023 / 052279. The inventors have also provided guidance on culturing algae with remoteoptical monitoring in United Kingdom Patent Application No. 2303165.1 and International PatentApplication No. PCT / GB2024 / 050542. The inventors have also provided guidance on carotenoidproduction methods in United Kingdom Patent Application No. 2301206.5 and International PatentApplication No. PCT / GB2024 / 050230. Each of these patent applications is incorporated herein byreference.The invention provides a method for producing a high value product (HVP), wherein the methodcomprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine HVP-producing microalgae ina first series of connected raceway ponds, arranged in stages, and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds inwhich algae are cultured in step (a), wherein the algae are cultured under stress conditions that induce the algae toincrease HVP production;(c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the inductionraceway pond(s) in which algae are cultured in step (b), and(d) an extraction phase, wherein the extraction phase comprises extracting the HVP from the algae harvested in step(c). In some embodiments, the carotenoid is beta-carotene. In some embodiments, the HVP comprises carbohydrates (e.g. polysaccharides), lipids, proteins, pigments and / or bioavailable minerals.In some embodiments, the HVP is a polysaccharide, lipid, protein, pigment, or bioavailable mineral.In some embodiments, the HVP comprises (UVB and UVC-resistant) phycocolloids and / or mycosporin-like amino acids (MAAs). In some embodiments, the HVP comprises phycobilin proteins, such as phycoerythrin, phycocyanin or allophycocyanin.In some embodiments, the HVP comprises lipids (e.g. fatty acids), and wherein the stress conditionscomprise nitrogen limitation (e.g. the concentration of nitrogen in the second algal culture phase isless than 10 μM).In some embodiments, the HVP comprises proteins (e.g. Rubisco) and / or carbohydrates, and whereinthe stress conditions comprise silicon limitation (e.g. the concentration of silicon in the second algalculture phase is less than 20 μM).In some embodiments, the stress conditions comprise nitrogen, phosphorus and / or silicon limitation, optionally wherein:(i) the concentration of nitrogen in the second algal culture phase is less than 10 μM,(ii) the concentration of phosphorus in the second algal culture phase is less than 20 μM, and / or(iii) the concentration of silicon in the second algal culture phase is less than 20 μM.In some embodiments, the stress conditions comprise nitrogen limitation, optionally wherein theconcentration of nitrogen in the second algal culture phase is less than 10 μM.In some embodiments, the stress conditions comprise high light. In some such embodiments, upontransfer into each of the one or more induction raceway ponds, the algae are cultured in water that isat least 10% shallower than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for at least the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the mean photosynthetically active radiation (PAR) and UV light does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the stress conditions comprise low light or a high ratio of orange to blue light. In some such embodiments, upon transfer into each of the one or more induction raceway ponds, the algae are cultured in water that is at least 10% deeper than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the stress conditions comprise low light or a high ratio of orange to blue light.In some such embodiments, the algae are cultured in deeper water, for at least the first day followingtransfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s).In some embodiments, the one or more induction raceway ponds in step (b) comprise at least twoinduction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in step (b) comprise at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, in each of the series of induction raceway ponds, the algae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, the penultimate induction raceway pond(s) in step (c) are each connected in parallel to at least two further, final raceway ponds. In some embodiments, the penultimate induction raceway pond(s) in step (c) are each connected inparallel to at least three further, final raceway ponds.In some embodiments, the final raceway ponds in step (c) are connected by pipes which permit the transfer of algal culture between the final raceway ponds.In some embodiments, the harvest phase comprises harvesting algae from one or more of the finalinduction raceway pond(s) in which algae are cultured in step (b). In some embodiments, the final induction raceway ponds are harvested in a staggered manner of at least two harvesting phases, comprising: (i) a first harvesting phase, wherein algae are harvested from one of the final raceway ponds, or simultaneously from two or more of the final raceway ponds, wherein algae are not harvested from at least one of the other final raceway ponds, and (ii) a second harvesting phase, wherein algae are harvested from one of the final raceway ponds or simultaneously from more than one of the final raceway ponds from which algae are not harvested in the first harvesting phase. In some embodiments, the second harvesting phase occurs at least one day after first harvesting phase.In some embodiments, the harvest phase further comprises the following step: (iii) a third harvesting phase, wherein algae are harvested from one of the final racewayponds or simultaneously from two or more of the final raceway ponds algae were not harvested in thefirst or second harvesting phases.In some embodiments, the third harvesting phase occurs at least one day after the second harvesting phase. In some embodiments, the final raceway ponds receive further algal culture from the penultimateraceway ponds in the second algal culture phase after harvest.In some embodiments, excess algal culture from one or more raceway ponds in steps (a) or (b) is removed by bleeding, optionally wherein the bled algal culture is introduced into one or more of the final raceway ponds of the second algal culture phase. In some embodiments, the harvesting algae in step (c) is from the final induction ponds. In some embodiments, the algae are green during the first algal culture phase, and wherein the algae become beige or orange during the second algal culture phase.In some embodiments, the marine HVP-producing microalgae are Chlorophyta, Chlorarachniophyta,Haptophyta, Dinophyta, Euglenophyta, Heterokontophyta (e.g. Chrysophyceae, Raphidophyceae,Bacillariophyceae, Phaeophyceae, Xanthophyceae or Eustigmatophyceae), Cryptophyta, unicellularRhodophyta, Glaucophyta or Cyanophyta, optionally wherein the marine carotenoid-producing microalgae are:(i) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema sp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., or(ii) Dunaliella sp.In some embodiments, the marine HVP-producing microalgae are Chlorophyta, Chlorarachniophyta,Haptophyta, Dinophyta, Euglenophyta, Heterokontophyta (e.g. Chrysophyceae, Raphidophyceae,Bacillariophyceae, Phaeophyceae, Xanthophyceae or Eustigmatophyceae), unicellular Rhodophyta,Glaucophyta or Cyanophyta, optionally wherein the marine HVP-producing microalgae are:Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema sp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., or (ii) Dunaliella sp.In some such embodiments, the marine HVP-producing microalgae are Dunaliella sp. (e.g. D. salina).In some embodiments, the HVP is a pigment. In some such embodiments, the pigment is acarotenoid (e.g. beta-carotene).In some embodiments, the carotenoid is a xanthophyll. In some embodiments, the xanthophyll is lutein. In some such embodiments, the marineHVP-producing microalgae are Chlorophyta (e.g. Dunaliella sp.) or Chlorarachniophyta. In some suchembodiments, the marine HVP-producing microalgae are Dunaliella sp. (e.g. D. salina).In some embodiments, the xanthophyll is: (A) diadinoxanthin,optionally wherein the marine HVP-producing microalgae are Heterokontophyta(e.g. Chrysophyceae, Raphidophyceae, Bacillariophyceae, Phaeophyceae, or Xanthophyceae),Haptophyta, Dinophyta or Euglenophyta, (B) zeaxanthin, optionally wherein the marine HVP-producing microalgae are Chlorophyta,Chlorarachniophyta, Haptophyta, Dinophyta, Euglenophyta, Heterokontophyta (e.g., Chrysophyceae, Raphidophyceae, Bacillariophyceae, Phaeophyceae, or Xanthophyceae), Cryptophyta, unicellular Rhodophyta, Glaucophyta or Cyanophyta, optionally further wherein the marine HVP-producing microalgae are:(i) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema spp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp., or Nitzschia sp., or(ii) Dunaliella sp., or (iii) Trichodesmium sp., Richelia sp., Calothrix sp., Crocosphaera sp., or CandidatusAtelocyanobacterium Thalassa, (C) violaxanthin, optionally wherein the marine HVP-producing microalgae are Chlorophyta (e.g. Dunaliellasp.), Chlorarachniophyta, or Heterokontophyta (e.g. Raphidophyceae, Phaeophyceae, orEustigmatophyceae), (D) neoxanthin, optionally wherein the marine HVP-producing microalgae are Euglenophyta, Chlorophyta(e.g. Dunaliella sp.) or Chlorarachniophyta,(E) fucoxanthin, optionally wherein the marine HVP-producing microalgae are Heterokontophyta(e.g. Chrysophyceae, Raphidophyceae, Bacillariophyceae, or Phaeophyceae), Haptophyta, orDinophyta, optionally further wherein the marine HVP-producing microalgae are Rhopalodiaceae sp.Hemiaulus sp., Climacodium sp., Skeletonema spp., Chaetoceros sp., Thalassiosira sp.,Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp.,(F) vaucheriaxanthin, optionally wherein the marine HVP-producing microalgae are Heterokontophyta(e.g. Chrysophyceae or Eustigmatophyceae),(G) loroxanthin, optionally wherein the marine HVP-producing microalgae are Euglenophyta, Chlorophyta(e.g. Prasinophyceae, Chlorophyceae or Ulvophyceae) or Chlorarachniophyta,(H) siphonaxanthin, optionally wherein the marine HVP-producing microalgae are Euglenophyta or Chlorophyta(e.g., Prasinophyceae, Chlorophyceae or Ulvophyceae), (I) one or more of nostoxanthin, echinenone, myxol glycosides and oscillol glycosides, optionally wherein the marine HVP-producing microalgae are Cyanophyta,optionally further wherein the marine HVP-producing microalgae are Trichodesmium sp.,Richelia sp., Calothrix sp., Crocosphaera sp. or Candidatus Atelocyanobacterium Thalassa,(J) one or more of alloxanthin, crocoxanthin and monadoxanthin,optionally wherein the marine HVP-producing microalgae are Cryptophyta,(K) violaxanthin fatty acid ester, optionally wherein the marine HVP-producing microalgae are Heterokontophyta(e.g., Xanthophyceae),(L) fucoxanthin fatty acid ester, optionally wherein the marine HVP-producing microalgae are Haptophyta, (M) peridinin, optionally wherein the marine HVP-producing microalgae are Dinophyta,(N) prasinoxanthin, optionally wherein the marine HVP-producing microalgae are Chlorophyta(e.g., Prasinophyceae),(O) loroxanthin fatty acid ester, optionally wherein the marine HVP-producing microalgae are Chlorophyta(e.g. Prasinophyceae) or Chlorarachniophyta, or(P) siphonaxanthin fatty acid ester, optionally wherein the marine HVP-producing microalgae are Chlorophyta(e.g. Prasinophyceae, Chlorophyceae or Ulvophyceae).In some embodiments, the HVP-producing microalgae are cyanobacteria or diatom-diazotroph assemblages (DDAs).In some embodiments, the marine HVP-producing microalgae are Dunaliella sp. (e.g. D. salina).In some embodiments, the algal culture is diluted in each raceway pond in the first algal culture phase, and wherein pond volume for each pond in the first algal culture phase is modelled by the following equation: ^ V ^ ^= V^ ∙ 2 ^^(^)^ wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algal culture phase, and wherein pond volume for each pond in the second algal culture phase is modelled by the following equation: ^ V ^ ^= V^ ∙ 2 ^^(^)^ wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond.In some embodiments, the algal growth rate during step (a) is at least 0.7d-1 (e.g.0.7-1.0 d-1) and / orwherein the algal growth rate at the end of step (b) is less than 0.6 d-1 (e.g.0.5 d-1).In some embodiments, the series of connected raceway ponds in step (a) is a linear series.In some embodiments, the series of connected raceway ponds in step (a) comprises a first stagecomprising one or more covered raceway ponds and a second stage comprising one or more stages of open raceway ponds.In some embodiments, one or more nutrient mineral acids are added during step (a), optionallywherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.In some embodiments, the concentration of nitrogen in step (b) is less than 10 μM.In some embodiments, the second algal culture phase is performed for at least four days (e.g. 4-10days). The invention further provides a raceway pond system, comprising: (a) a linear series of connected raceway ponds comprising a first stage comprising one or more covered raceway ponds and a second stage comprising one or more open raceway ponds; and (b) at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the linear series of connected raceway ponds, wherein each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds in the raceway pond system comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. The invention further provides a raceway pond system for use in culturing marine microalgae, the raceway pond system comprising: (a) a linear series of connected raceway ponds comprising a first stage comprising one or more covered raceway ponds and a second stage comprising one or more open raceway ponds; and (b) at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the linear series of connected raceway ponds, wherein each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, the culture medium in the raceway pond system is seawater. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates an example raceway pond according to the invention. Figure 2A illustrates an algal cultivation system and depicts a series of connected raceway ponds arranged in stages. Figure 2B illustrates a subsection of the algal cultivation system of Figure 2A.Figure 3 illustrates exemplary extraction methods according to the invention. Figure 4A is a chromatogram for crude carotenoid extract. Figure 4B is a chromatogram forcarotenoid powder 84% all-trans beta carotene. Figure 4C is a chromatogram for BASF Betatene®30% OLV, 72% all-trans beta carotene.Figure 5A is a chromatogram for lutein extract (45 min run time). Figure 5B is a chromatogram forlutein extract (60 min run time).Figure 6 is a chromatogram for crude extract obtained from Skeletonema pseudocostatum.Figure 7 provides structural formulae for some exemplary carotenoids. This figure is reproduced from Takaichi 2011.Figure 8 provides a summary of carotenoid distribution in algae. This figure is reproduced fromTakaichi 2011. (Key: H, Major carotenoid in most species of the class; L, Low content in most speciesor major carotenoid in some species. α, α-carotene; β, β-carotene; Al, alloxanthin; Cr, crocoxanthin; Da, diatoxanthin; Dd, diadinoxanthin; Ec, echinenone; FA, fatty acid ester; Fx, fucoxanthin; Lo, loroxanthin; Lu, lutein; Mo, monadoxanthin; My, myxol glycosides and oscillol glycosides; Ne, neoxanthin; No, nostoxanthin; Pe, peridinin; Pr, prasinoxanthin; Sx, siphonaxanthin; Va, vaucheriaxanthin; Vi, violaxanthin; Ze, zeaxanthin). Lu, Lo, Lo-FA, Cr, Mo, Pr, Sx and Sx-FA are α-carotene derivatives. Figure 9 provides an overhead view of a production pond containing a central divider, paddlewheel and deflectors, where a) is the channel length, b) is the pond length, c) is the channel width and d) is the pond width. Multiplying a) by d) gives the centre pond area. The pond aspect ratio is calculated by dividing a) by c). This ratio can be adjusted without effecting the pond gas exchange rates as pond surface area is constant. A ratio of 8 is advantageous in that it facilitates construction from the geomembrane roll and optimises for centre channel mixing velocities. Figure 10 shows modelled in-pond Spectral Photosynthetic Active Radiation (SPAR) at the surface(0m), half fill depth (0.5m) and full pond depth (1m) for Dunaliella salina. The differences in SPAR atdepth is due to differences in species-specific absorption and / or scattering properties. The sum of all SPAR values at a specific depth within the visible range (λ400-700) equals the PAR (µmol photons m-2s-1) at that same depth. DETAILED DESCRIPTION OF THE INVENTION High value products As used herein, the term “high value product” (or “HVP”) refers to a biomolecule or other substance which can be produced by and extracted from algae, and which is of commercial value and / or interest. In some embodiments, a high value product could be a stress induced product or stress enhanced product. The terms “stress induced product” and “stress enhanced product” refer to biomolecules or other substances which are produced by algae in higher concentrations or quantities under stress conditions compared to normal conditions. In some embodiments, the high value product comprises one or more of a pigment, a protein, a lipid, a carbohydrate and / or a bioavailable mineral. In some embodiments, the high value product is a pigment. In some embodiments, the high value product is a protein. In some embodiments, the high value product is a lipid. In some embodiments,the high value product is a carbohydrate. In some embodiments, the high value product is abioavailable mineral. Pigments In some embodiments, the HVP is a pigment. In some embodiments, the pigment is a carotenoid. Insome embodiments, the carotenoid is a carotene (e.g. beta-carotene). Carotenes are one of the twomajor divisions of carotenoids. The other division is formed by the xanthophylls. While carotenes are purely hydrocarbons, xanthophylls contain oxygen atoms, typically as a hydroxyl group. Carotenes are terpenoids assembled from eight isoprene units resulting in 40 branched and double bonded carbon atoms, capped with beta-ionone rings at each end.Beta-carotene is a member of the carotene family of compounds. In nature, beta-carotene isbiosynthesized from geranylgeranyl pyrophosphate. Like most of the naturally occurring carotenoids, it is strongly colored and highly lipophilic (since it lacks functional groups). The invention provides a method for producing a pigment, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine pigment-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds inwhich algae are cultured in step (a), and wherein the algae are cultured:(i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of a low concentration of nitrogen (e.g. less than 10 µMnitrogen), thereby inducing the algae to increase production of pigment; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the inductionraceway pond(s) in which algae are cultured in step (b), and(d) an extraction phase, wherein the extraction phase comprises extracting pigment from the algae harvested in step(c).In some embodiments, upon transfer into each of the one or more induction raceway ponds, the algaeare cultured in water that is at least 10%, at least 15%, at least 20%, or at least 25% shallower thanthe water in which the algae are cultured in the final raceway pond of the first series of connectedraceway ponds. In some embodiments, upon transfer into each of the one or more induction racewayponds, the algae are cultured in water that is 10-25% shallower than the water in which the algae arecultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for at least the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the mean photosynthetically active radiation (PAR) and UV light does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s). Advantageously, this enhances paddlewheel mixing and reduces the likelihood of overexposure to UV.In some embodiments, the one or more induction raceway ponds in the second algal culture phasecomprise at least two induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, in each of the series of induction raceway ponds, the algae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, algae are harvested from the final induction pond(s).In some embodiments, the algae are green during the first algal culture phase. In some embodiments,the algae become beige or orange during the second algal culture phase.In preferred embodiments, the pigment is beta-carotene. In some such embodiments, the marinepigment-producing microalgae are Cyanophyta, Glaucophyta, unicellular Rhodophyta,Heterokontophyta, Haptophyta, Dinophyta, Euglenophyta, Chlorarachniophyta or Chlorophyta(e.g., Prasinophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae or Charophyceae). In somesuch embodiments, the marine carotenoid-producing microalgae are Cyanophyta, Glaucophyta,unicellular Rhodophyta, Heterokontophyta, Haptophyta, Euglenophyta, Chlorarachniophyta orChlorophyta (e.g., Prasinophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae orCharophyceae).In some such embodiments, the marine pigment-producing microalgae are:(i) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema sp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., or(ii) Dunaliella sp..In some such embodiments, the marine pigment-producing microalgae are Dunaliella sp., such asDunaliella salina. In some embodiments, the algal culture is diluted in each raceway pond in the first algal culture phase, and wherein pond volume for each pond in the first algal culture phase is modelled by the following equation: ^ V ^ ^= V^ ∙ 2^^(^)^ wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algal culture phase, and wherein pond volume for each pond in the second algal culture phase is modelled by the following equation: ^ V ^ ^= V^ ∙ 2^^(^)^ wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond.In some embodiments, the algal growth rate during step (a) is at least 0.7d-1 (e.g.0.7-1.0 d-1) and / orwherein the algal growth rate at the end of step (b) is less than 0.6 d-1 (e.g.0.5 d-1).In some embodiments, the series of connected raceway ponds in the first algal culture phase is a linear series.In some embodiments, the series of connected raceway ponds in the first algal culture phasecomprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more stages of open raceway ponds.In some embodiments, one or more nutrient mineral acids are added during the first algal culturephase, optionally wherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.In some embodiments, the concentration of nitrogen in step (b) is less than 10 μM.In some embodiments, the second algal culture phase is performed for at least four days (e.g.4-10days). In some embodiments, the carotene is alpha-carotene. In some such embodiments, the marinecarotenoid-producing microalgae are Cyanophyta, Cryptophyta, Prasinophyceae, Chlorophyceae or Ulvophyceae. In some such embodiments, the marine carotenoid-producing microalgae are Cryptophyta or Chlorophyceae. in combination with The invention further provides methods that involve deliberately inducing the formation of HVPs by stressing the cells through increasing light exposure and high salinity. The statements above regarding step (d) are applicable to these methods too. Similarly, the statements regarding steps (a),(b), (c) and (d) provided elsewhere herein are also applicable to these methods.Such methods include a method for producing a HVP, wherein the method comprises: (a) a first algal culture phase, wherein the first algal culture phase comprises culturing marine HVP-producing microalgae in a first series of connected raceway ponds, arranged in stages, and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of the presence of high salinity (e.g. at least 40 parts perthousand (‰)), thereby inducing the algae to increase HVP production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b), and (d) an extraction phase, wherein the extraction phase comprises extracting the HVP from the algae harvested in step(c).In some embodiments, the algae are induced to produce the HVP by culturing the algae with highsalinity. In some embodiments, the algae are cultured at a salinity of at least 40 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 50 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 60 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 70 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 80 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 90 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 100 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 110 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 120 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 130 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 140 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 150 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 160 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 170 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 180 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 190 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 200 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of 40-200 parts per thousand (‰).In some embodiments, upon transfer into each of the one or more induction raceway ponds, the algaeare cultured in water that is at least 10%, at least 15%, at least 20%, or at least 25% shallower than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, upon transfer into each of the one or more induction racewayponds, the algae are cultured in water that is 10-25% shallower than the water in which the algae arecultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for at least the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the mean photosynthetically active radiation (PAR) and UV light does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s). Advantageously, this enhances paddlewheel mixing and reduces the likelihood of overexposure to UV.In some embodiments, the one or more induction raceway ponds in the second algal culture phasecomprise at least two induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, in each of the series of induction raceway ponds, the algae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, algae are harvested from the final induction pond(s). In some embodiments, the algae are green during the first algal culture phase. In some embodiments, the algae become beige or orange during the second algal culture phase. In some embodiments, the HVP is a pigment. In some embodiments, the pigment is a carotenoid. Insome embodiments, the carotenoid is a carotene (e.g. beta-carotene).In some embodiments, the HVP is beta-carotene. In some such embodiments, the marineHVP-producing microalgae are Cyanophyta, Glaucophyta, unicellular Rhodophyta, Heterokontophyta,Haptophyta, Dinophyta, Euglenophyta, Chlorarachniophyta or Chlorophyta (e.g., Prasinophyceae,Chlorophyceae, Ulvophyceae, Trebouxiophyceae or Charophyceae). In some such embodiments, themarine HVP-producing microalgae are Cyanophyta, Glaucophyta, unicellular Rhodophyta,Heterokontophyta, Haptophyta, Euglenophyta, Chlorarachniophyta or Chlorophyta(e.g., Prasinophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae or Charophyceae).In some such embodiments, the marine HVP-producing microalgae are:(i) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema sp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., or(ii) Dunaliella sp..In some such embodiments, the marine HVP-producing microalgae are Dunaliella sp., such asDunaliella salina. In some embodiments, the algal culture is diluted in each raceway pond in the first algal culture phase, and wherein pond volume for each pond in the first algal culture phase is modelled by the following equation: ^ V= V ∙ 2^ ^^(^)^ ^^wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algal culture phase, and wherein pond volume for each pond in the second algal culture phase is modelled by the following equation: ^ V ^ ^= V^ ∙ 2 ^^(^)^ wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond.In some embodiments, the algal growth rate during step (a) is at least 0.7d-1 (e.g.0.7-1.0 d-1) and / orwherein the algal growth rate at the end of step (b) is less than 0.6 d-1 (e.g.0.5 d-1).In some embodiments, the series of connected raceway ponds in the first algal culture phase is a linear series.In some embodiments, the series of connected raceway ponds in the first algal culture phasecomprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more stages of open raceway ponds.In some embodiments, one or more nutrient mineral acids are added during the first algal culturephase, optionally wherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.In some embodiments, the second algal culture phase is performed for at least four days (e.g.4-10days). In some embodiments, the carotene is alpha-carotene. In some such embodiments, the marinecarotenoid-producing microalgae are Cyanophyta, Cryptophyta, Prasinophyceae, Chlorophyceae orUlvophyceae. In some such embodiments, the marine carotenoid-producing microalgae are Cryptophyta or Chlorophyceae. High light in combination with low temperatureThe invention further provides methods that involve deliberately inducing the formation of HVPs (e.g.pigments, such as carotenoids) by stressing the cells through increasing light exposure and lowtemperature. The statements above regarding step (d) are applicable to these methods too. Similarly, the statements regarding steps (a), (b), (c) and (d) provided elsewhere herein are also applicable to these methods. Such methods also include a method for producing a HVP, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine HVP-producing microalgae ina first series of connected raceway ponds, arranged in stages, and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) at a low temperature (e.g. less than 20°C),thereby inducing the algae to increase HVP production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b), and (d) an extraction phase, wherein the extraction phase comprises extracting the HVP from the algae harvested in step (c).In some embodiments, the algae are induced to produce the HVP by culturing the algae at lowtemperature. In some embodiments, the algae are cultured at a temperature of less than 20 °C. Insome embodiments, the algae are cultured at a temperature of less than 18 °C. In someembodiments, the algae are cultured at a temperature of less than 15 °C. In some embodiments, thealgae are cultured at a temperature of less than 12 °C. In some embodiments, the algae are culturedat a temperature of less than 10 °C.In some embodiments, the algae are cultured at a temperature of between 12 °C and 20 °C. In someembodiments, the algae are cultured at a temperature of between 12 °C and 18 °C.In some embodiments, upon transfer into each of the one or more induction raceway ponds, the algaeare cultured in water that is at least 10%, at least 15%, at least 20%, or at least 25% shallower than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, upon transfer into each of the one or more induction racewayponds, the algae are cultured in water that is 10-25% shallower than the water in which the algae arecultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for at least the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the mean photosynthetically active radiation (PAR) and UV light does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s). Advantageously, this enhances paddlewheel mixing and reduces the likelihood of overexposure to UV.In some embodiments, the one or more induction raceway ponds in the second algal culture phasecomprise at least two induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, in each of the series of induction raceway ponds, the algae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, algae are harvested from the final induction pond(s). In some embodiments, the algae are green during the first algal culture phase. In some embodiments, the algae become beige or orange during the second algal culture phase. In some embodiments, the HVP is a pigment. In some embodiments, the pigment is a carotenoid. Insome embodiments, the carotenoid is a carotene (e.g. beta-carotene).In some embodiments, the HVP is beta-carotene. In some such embodiments, the marineHVP-producing microalgae are Cyanophyta, Glaucophyta, unicellular Rhodophyta, Heterokontophyta,Haptophyta, Dinophyta, Euglenophyta, Chlorarachniophyta or Chlorophyta (e.g., Prasinophyceae,Chlorophyceae, Ulvophyceae, Trebouxiophyceae or Charophyceae). In some such embodiments, themarine HVP-producing microalgae are Cyanophyta, Glaucophyta, unicellular Rhodophyta,Heterokontophyta, Haptophyta, Euglenophyta, Chlorarachniophyta or Chlorophyta(e.g., Prasinophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae or Charophyceae).In some such embodiments, the marine HVP-producing microalgae are:(i) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema sp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., or(ii) Dunaliella sp..In some such embodiments, the marine HVP-producing microalgae are Dunaliella sp., such asDunaliella salina. In some embodiments, the algal culture is diluted in each raceway pond in the first algal culture phase, and wherein pond volume for each pond in the first algal culture phase is modelled by the following equation: ^ V ^ ^= V^ ∙ 2^^(^)^ wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algal culture phase, and wherein pond volume for each pond in the second algal culture phase is modelled by the following equation: ^ V ^ ^^(^)^ ^= V^ ∙ 2wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond.In some embodiments, the algal growth rate during step (a) is at least 0.7d-1 (e.g.0.7-1.0 d-1) and / orwherein the algal growth rate at the end of step (b) is less than 0.6 d-1 (e.g.0.5 d-1).In some embodiments, the series of connected raceway ponds in the first algal culture phase is a linear series.In some embodiments, the series of connected raceway ponds in the first algal culture phasecomprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more stages of open raceway ponds.In some embodiments, one or more nutrient mineral acids are added during the first algal culturephase, optionally wherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.In some embodiments, the second algal culture phase is performed for at least four days (e.g.4-10days). In some embodiments, the carotene is alpha-carotene. In some such embodiments, the marinecarotenoid-producing microalgae are Cyanophyta, Cryptophyta, Prasinophyceae, Chlorophyceae orUlvophyceae. In some such embodiments, the marine carotenoid-producing microalgae are Cryptophyta or Chlorophyceae. The invention further provides methods of xanthophyll production, including methods of lutein, zeaxanthin and violaxanthin production. Xanthophylls In some embodiments, the HVP is a xanthophyll. Xanthophylls are one of the two major divisions of carotenoids. The other division is formed by the carotenes. While carotenes are purely hydrocarbons, xanthophylls contain oxygen atoms, typically as a hydroxyl group. The invention provides a method for producing a xanthophyll, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine carotenoid-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of a low concentration of nitrogen (e.g. less than 10 µMnitrogen), thereby inducing the algae to increase xanthophyll production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase,wherein the extraction phase comprises extracting the xanthophyll from the algae harvestedin step (c). In some embodiments, the xanthophyll is lutein. In some such embodiments, the marinecarotenoid-producing microalgae are Chlorophyta (e.g., Dunaliella sp.) or Chlorarachniophyta. Insome such embodiments, the marine carotenoid-producing microalgae are Chlorophyceae,Trebouxiophyceae or Charophyceae. In some embodiments, the xanthophyll is diadinoxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Heterokontophyta (e.g., Chrysophyceae, Raphidophyceae,Bacillariophyceae, Phaeophyceae, or Xanthophyceae), Haptophyta, Dinophyta or Euglenophyta. Insome such embodiments, the marine carotenoid-producing microalgae are Rhopalodiaceae sp.Hemiaulus sp., Climacodium sp., Skeletonema spp., Chaetoceros sp., Thalassiosira sp.,Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp.In some embodiments, the xanthophyll is diadinoxanthin and the marine carotenoid-producingmicroalgae are Xanthophyceae, Haptophyta, Dinophyta or Euglenophyta.In some embodiments, the xanthophyll is zeaxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Chlorophyta, Chlorarachniophyta, Haptophyta, Dinophyta,Euglenophyta, Heterokontophyta (e.g., Chrysophyceae, Raphidophyceae, Bacillariophyceae,Phaeophyceae, or Xanthophyceae), Cryptophyta, unicellular Rhodophyta, Glaucophyta orCyanophyta. In some such embodiments, the marine carotenoid-producing microalgae are(i) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema spp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., (ii) Dunaliella sp.In some embodiments, the xanthophyll is zeaxanthin and the marine carotenoid-producing microalgaeare Cyanophyta, Glaucophyta, unicellular Rhodophyta, Raphidophyceae or Phaeophyceae.In some embodiments, the xanthophyll is violaxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Chlorophyta (e.g., Dunaliella sp.), Chlorarachniophyta, orHeterokontophyta (e.g., Raphidophyceae, Phaeophyceae, or Eustigmatophyceae). In some suchembodiments, the marine carotenoid-producing microalgae are Chlorophyta (e.g., Prasinophyceae,Chlorophyceae, Ulvophyceae, Trebouxiophyceae or Charophyceae), Phaeophyceae or Eustigmatophyceae. In some embodiments, the xanthophyll is neoxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Euglenophyta, Chlorophyta (e.g., Dunaliella sp.) orChlorarachniophyta. In some such embodiments, the marine carotenoid-producing microalgae areChlorophyta (e.g., Prasinophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae orCharophyceae). In some embodiments, the xanthophyll is fucoxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Heterokontophyta (e.g., Chrysophyceae, Raphidophyceae,Bacillariophyceae, or Phaeophyceae), Haptophyta, or Dinophyta. In some such embodiments, themarine carotenoid-producing microalgae are Rhopalodiaceae sp. Hemiaulus sp., Climacodium sp.,Skeletonema spp., Chaetoceros sp., Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp.or Nitzschia sp.In some embodiments, the xanthophyll is fucoxanthin and the marine carotenoid-producingmicroalgae are Chrysophyceae, Bacillariophyceae, Phaeophyceae or Haptophyta.In some embodiments, the xanthophyll is vaucheriaxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Heterokontophyta (e.g., Chrysophyceae or Eustigmatophyceae).In some embodiments, the xanthophyll is loroxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Euglenophyta, Chlorophyta (e.g., Prasinophyceae,Chlorophyceae or Ulvophyceae) or Chlorarachniophyta,In some embodiments, the xanthophyll is siphonaxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Euglenophyta or Chlorophyta (e.g., Prasinophyceae,Chlorophyceae or Ulvophyceae). In some such embodiments, the marine carotenoid-producingmicroalgae are Prasinophyceae.In some embodiments, the xanthophyll is one or more of nostoxanthin, echinenone, myxol glycosidesand oscillol glycosides. In some such embodiments, the marine carotenoid-producing microalgae areCyanophyta. In some embodiments, the xanthophyll is one or more of echinenone, myxol glycosides and oscillolglycosides. In some such embodiments, the marine carotenoid-producing microalgae areCyanophyta.In some embodiments, the xanthophyll is one or more of alloxanthin, crocoxanthin andmonadoxanthin. In some such embodiments, the marine carotenoid-producing microalgae areCryptophyta. In some embodiments, the xanthophyll is violaxanthin fatty acid ester. In some such embodiments,the marine carotenoid-producing microalgae are Heterokontophyta (e.g., Xanthophyceae),In some embodiments, the xanthophyll is fucoxanthin fatty acid ester. In some such embodiments, themarine carotenoid-producing microalgae are Haptophyta.In some embodiments, the xanthophyll is peridinin. In some such embodiments, the marinecarotenoid-producing microalgae are Dinophyta.In some embodiments, the xanthophyll is prasinoxanthin. In some such embodiments, the marinecarotenoid-producing microalgae are Chlorophyta (e.g., Prasinophyceae),In some embodiments, the xanthophyll is loroxanthin fatty acid ester. In some such embodiments, themarine carotenoid-producing microalgae are Chlorophyta (e.g., Prasinophyceae) orChlorarachniophyta.In some embodiments, the xanthophyll is siphonaxanthin fatty acid ester. In some such embodiments,the marine carotenoid-producing microalgae are Chlorophyta (e.g., Prasinophyceae, Chlorophyceaeor Ulvophyceae). In some such embodiments, the marine carotenoid-producing microalgae arePrasinophyceae or Ulvophyceae.In some embodiments, the marine carotenoid-producing microalgae are Cyanophyta. In some suchembodiments, the xanthophyll is one or more of zeaxanthin, nostoxanthin, echinenone, myxol glycosides and oscillol glycosides. In some such embodiments, the xanthophyll is one or more of zeaxanthin, echinenone, myxol glycosides and oscillol glycosides.In some embodiments, the marine carotenoid-producing microalgae are Glaucophyta. In some suchembodiments, the xanthophyll is zeaxanthin.In some embodiments, the marine carotenoid-producing microalgae are Rhodophyta. In some suchembodiments, the xanthophyll is zeaxanthin.In some embodiments, the marine carotenoid-producing microalgae are Cryptophyta. In some suchembodiments, the xanthophyll is one or more of alloxanthin, crocoxanthin and monadoxanthin.In some embodiments, the marine carotenoid-producing microalgae are Chrysophyceae. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, diatoxanthin, diadinoxanthin,fucoxanthin and vaucheriaxanthin. In some such embodiments, the xanthophyll is fucoxanthin.In some embodiments, the marine carotenoid-producing microalgae are Raphidophyceae. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, violaxanthin, diatoxanthin,diadinoxanthin and fucoxanthin. In some such embodiments, the xanthophyll is zeaxanthin.In some embodiments, the marine carotenoid-producing microalgae are Bacillariophyceae. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, diatoxanthin, diadinoxanthin andfucoxanthin. In some such embodiments, the xanthophyll is fucoxanthin.In some embodiments, the marine carotenoid-producing microalgae are Phaeophyceae. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, violaxanthin, diatoxanthin,diadinoxanthin and fucoxanthin. In some such embodiments, the xanthophyll is one or more ofzeaxanthin, violaxanthin and fucoxanthin.In some embodiments, the marine carotenoid-producing microalgae are Xanthophyceae. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, diatoxanthin, diadinoxanthin andviolaxanthin fatty acid ester. In some such embodiments, the xanthophyll is one or more ofdiatoxanthin and diadinoxanthin.In some embodiments, the marine carotenoid-producing microalgae are Eustigmatophyceae. In somesuch embodiments, the xanthophyll is one or more of violaxanthin and vaucheriaxanthin. In somesuch embodiments, the xanthophyll is violaxanthin.In some embodiments, the marine carotenoid-producing microalgae are Haptophyta. In some suchembodiments, the xanthophyll is one or more of zeaxanthin, diatoxanthin, diadinoxanthin, fucoxanthinand fucoxanthin fatty acid ester. In some such embodiments, the xanthophyll is one or more ofdiadinoxanthin and fucoxanthin.In some embodiments, the marine carotenoid-producing microalgae are Dinophyta. In some suchembodiments, the xanthophyll is one or more of zeaxanthin, diatoxanthin, diadinoxanthin, fucoxanthinand peridinin. In some such embodiments, the xanthophyll is one or more of diadinoxanthin andperidinin.In some embodiments, the marine carotenoid-producing microalgae are Euglenophyta. In some suchembodiments, the xanthophyll is one or more of zeaxanthin, neoxanthin, diatoxanthin, diadinoxanthin,loroxanthin and siphonaxanthin. In some such embodiments, the xanthophyll is diadinoxanthin.In some embodiments, the marine carotenoid-producing microalgae are Chlorarachniophyta. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, violaxanthin, neoxanthin, lutein,loroxanthin and loroxanthin fatty acid ester.In some embodiments, the marine carotenoid-producing microalgae are Prasinophyceae. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, violaxanthin, neoxanthin, lutein,loroxanthin, siphonaxanthin, prasinoxanthin, loroxanthin fatty acid ester and siphonaxanthin fatty acidester. In some such embodiments, the xanthophyll is one or more of violaxanthin, neoxanthin,siphonaxanthin and siphonaxanthin fatty acid ester.In some embodiments, the marine carotenoid-producing microalgae are Chlorophyceae. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, violaxanthin, neoxanthin, lutein,loroxanthin, siphonaxanthin and and siphonaxanthin fatty acid ester. In some such embodiments, thexanthophyll is one or more of violaxanthin, neoxanthin and lutein.In some embodiments, the marine carotenoid-producing microalgae are Ulvophyceae. In some suchembodiments, the xanthophyll is one or more of zeaxanthin, violaxanthin, neoxanthin, lutein,loroxanthin, siphonaxanthin and siphonaxanthin fatty acid ester. In some such embodiments, thexanthophyll is one or more of violaxanthin, neoxanthin and siphonaxanthin fatty acid ester.In some embodiments, the marine carotenoid-producing microalgae are Trebouxiophyceae. In somesuch embodiments, the xanthophyll is one or more of zeaxanthin, violaxanthin, neoxanthin and lutein.In some such embodiments, the xanthophyll is one or more of violaxanthin, neoxanthin and lutein.In some embodiments, the marine carotenoid-producing microalgae are Charophyceae. In some suchembodiments, the xanthophyll is one or more of zeaxanthin, violaxanthin, neoxanthin and lutein. Insome such embodiments, the xanthophyll is one or more of violaxanthin, neoxanthin and lutein.The invention further provides a method for producing a xanthophyll, wherein the method comprises: (d) a first algal culture phase,wherein the first algal culture phase comprises culturing marine carotenoid-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of the presence of high salinity (e.g. at least 40 parts perthousand (‰)), thereby inducing the algae to increase xanthophyll production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the xanthophyll from the algae harvestedin step (c). The invention further provides a method for producing a xanthophyll, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine carotenoid-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) at a low temperature (e.g. less than 20°C),thereby inducing the algae to increase xanthophyll production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the xanthophyll from the algae harvestedin step (c). The examples demonstrate the production of an exemplary xanthophyll, lutein. In view of the structural similarity between lutein and other marine microalgae-produced xanthophylls, the lutein production methods described herein are broadly applicable to xanthophylls in general, and the specific xanthophylls discussed above. Lutein production The invention provides a method for producing lutein, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine lutein-producingmicroalgae in a first series of connected raceway ponds, arranged in stages, and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of a low concentration of nitrogen (e.g. less than 10 µMnitrogen), thereby inducing the algae to increase lutein production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the lutein from the algae harvested in step(c).In some embodiments, the marine lutein-producing microalgae are Chlorophyta (e.g., Dunaliella sp.)or Chlorarachniophyta. In some such embodiments, the lutein carotenoid-producing microalgae areChlorophyceae, Trebouxiophyceae or Charophyceae.The invention further provides a method for producing lutein, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine lutein-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of the presence of high salinity (e.g. at least 40 parts perthousand (‰)), thereby inducing the algae to increase lutein production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the lutein from the algae harvested in step(c). The invention provides a method for producing lutein, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine lutein-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) at a low temperature (e.g. less than 20°C),thereby inducing the algae to increase lutein production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the lutein from the algae harvested in step(c). Zeaxanthin production The invention provides a method for producing zeaxanthin, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine zeaxanthin-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and(ii) in the presence of a low concentration of nitrogen (e.g. less than 10 µMnitrogen), thereby inducing the algae to increase zeaxanthin production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the zeaxanthin from the algae harvested instep (c).In some embodiments, the marine zeaxanthin-producing microalgae are Chlorophyta,Chlorarachniophyta, Haptophyta, Dinophyta, Euglenophyta, Heterokontophyta (e.g., Chrysophyceae, Raphidophyceae, Bacillariophyceae, Phaeophyceae, or Xanthophyceae), Cryptophyta, unicellularRhodophyta, Glaucophyta or Cyanophyta. In some such embodiments, the zeaxanthin carotenoid-producing microalgae are(i) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema spp., Chaetocerossp., Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., (ii)Dunaliella sp.The invention further provides a method for producing zeaxanthin, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine zeaxanthin-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of the presence of high salinity (e.g. at least 40 parts perthousand (‰)), thereby inducing the algae to increase zeaxanthin production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the zeaxanthin from the algae harvested instep (c). The invention further provides a method for producing zeaxanthin, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine zeaxanthin-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) at a low temperature (e.g. less than 20°C),thereby inducing the algae to increase zeaxanthin production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the zeaxanthin from the algae harvested instep (c). Violaxanthin production The invention provides a method for producing violaxanthin, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marineviolaxanthin-producing microalgae in a first series of connected raceway ponds, arranged instages, and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of a low concentration of nitrogen (e.g. less than 10 µMnitrogen), thereby inducing the algae to increase violaxanthin production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the violaxanthin from the algae harvestedin step (c).In some embodiments, the marine violaxanthin-producing microalgae are Chlorophyta(e.g., Dunaliella sp.), Chlorarachniophyta, or Heterokontophyta (e.g., Raphidophyceae,Phaeophyceae, or Eustigmatophyceae). In some such embodiments, the marine carotenoid-producing microalgae are Chlorophyta (e.g., Prasinophyceae, Chlorophyceae, Ulvophyceae,Trebouxiophyceae or Charophyceae), Phaeophyceae or Eustigmatophyceae. The invention provides a method for producing violaxanthin, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marineviolaxanthin-producing microalgae in a first series of connected raceway ponds, arranged instages, and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) in the presence of the presence of high salinity (e.g. at least 40 parts perthousand (‰)), thereby inducing the algae to increase violaxanthin production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the violaxanthin from the algae harvestedin step (c). The invention provides a method for producing violaxanthin, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marineviolaxanthin-producing microalgae in a first series of connected raceway ponds, arranged instages, and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition; (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured: (i) in shallower water upon transfer into each of the one or more inductionraceway ponds than in the final raceway pond of the first series of connected raceway ponds, and (ii) at a low temperature (e.g. less than 20°C),thereby inducing the algae to increase violaxanthin production; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and (d) an extraction phase, wherein the extraction phase comprises extracting the violaxanthin from the algae harvestedin step (c). Proteins In some embodiments, the HVP is a protein. As used herein, the term “protein” encompasses polypeptides, dipeptides, and amino acids. The invention provides a method for producing a protein, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine protein-producing microalgaein a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured under stress conditions that induce the algae to increase protein production thereby inducing the algae to increase production of protein; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b), and (d) an extraction phase, wherein the extraction phase comprises extracting protein from the algae harvested in step (c).In some embodiments, upon transfer into each of the one or more induction raceway ponds, the algaeare cultured in water that is at least 10%, at least 15%, at least 20%, or at least 25% shallower than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, upon transfer into each of the one or more induction racewayponds, the algae are cultured in water that is 10-25% shallower than the water in which the algae arecultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for at least the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the mean photosynthetically active radiation (PAR) and UV light does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s). Advantageously, this enhances paddlewheel mixing and reduces the likelihood of overexposure to UV.In some embodiments, the one or more induction raceway ponds in the second algal culture phasecomprise at least two induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, in each of the series of induction raceway ponds, the algae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, algae are harvested from the final induction pond(s). In some embodiments, the algae are green during the first algal culture phase. In some embodiments, the algae become beige or orange during the second algal culture phase. In some embodiments, the stress conditions that induce the algae to increase protein productioncomprise nutrient limitation, high salinity, low temperature, and / or increasing light exposure.In some embodiments, nutrient limitation comprises limitation of one or more of nitrogen, phosphorous and / or silicon. In some embodiments, the stress conditions that induce the algae to increase protein productioncomprise the presence of a low concentration of nitrogen (e.g. less than 10 μM nitrogen). In someembodiments, the stress conditions that induce the algae to increase protein production comprise thepresence of a low concentration of phosphorus (e.g. less than 20 μM phosphorus). In someembodiments, the stress conditions that induce the algae to increase protein production comprise thepresence of a low concentration of silicon (e.g. less than 20 μM silicon).In some embodiments, the protein comprises mycosporin-like amino acids (MAAs). In some embodiments, the protein comprises phycobilin proteins. In some such embodiments, the phycobilin protein is selected from phycoerythrin, phycocyanin or allophycocyanin. In some embodiments, the phycobilin protein is phycoerythrin. In some embodiments, the phycobilin protein is phycocyanin. In some embodiments, the phycobilin protein is allophycocyanin. In some embodiments, the protein is Rubisco. In some embodiments, the protein comprises mycosporin-like amino acids (MAAs). In some embodiments, protein is a mycosporin-like amino acid (MAA). In some embodiments, the protein is a phycobilin protein. In some embodiments, the phycobilin protein comprises phycoerythrin, phycocyanin or allophycocyanin. In some embodiments, the phycobilin protein is phycoerythrin. In some embodiments, the phycobilin protein is phycocyanin. In some embodiments, the phycobilin protein is allophycocyanin. In some embodiments, the protein is selected from Rubisco, one or more mycosporin-like amino acids (MAAs), one or more phycobilin proteins, phycoerythrin, phycocyanin and / or allophycocyanin. In some embodiments, the algal culture is diluted in each raceway pond in the first algal culture phase, and wherein pond volume for each pond in the first algal culture phase is modelled by the following equation: ^ V=^^^(^)^ ^V^ ∙ 2wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algal culture phase, and wherein pond volume for each pond in the second algal culture phase is modelled by the following equation: ^ V= V^^^(^)^ ^^ ∙ 2wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond.In some embodiments, the algal growth rate during step (a) is at least 0.7d-1 (e.g.0.7-1.0 d-1) and / orwherein the algal growth rate at the end of step (b) is less than 0.6 d-1 (e.g.0.5 d-1). In some embodiments, the series of connected raceway ponds in the first algal culture phase is a linear series.In some embodiments, the series of connected raceway ponds in the first algal culture phasecomprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more stages of open raceway ponds.In some embodiments, one or more nutrient mineral acids are added during the first algal culturephase, optionally wherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.In some embodiments, the second algal culture phase is performed for at least four days (e.g.4-10days). Carbohydrates In some embodiments, the HVP is a carbohydrate. As used herein, the term “carbohydrate” also encompasses sugar(s), polysaccharides and monosaccharides. The invention provides a method for producing a carbohydrate, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine carboydrate-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured under stress conditions that induce the algae to increase carbohydrate production thereby inducing the algae to increase production of carbohydrate; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b), and (d) an extraction phase, wherein the extraction phase comprises extracting carbohydrate from the algae harvested in step (c).In some embodiments, upon transfer into each of the one or more induction raceway ponds, the algaeare cultured in water that is at least 10%, at least 15%, at least 20%, or at least 25% shallower than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, upon transfer into each of the one or more induction racewayponds, the algae are cultured in water that is 10-25% shallower than the water in which the algae arecultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for at least the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the mean photosynthetically active radiation (PAR) and UV light does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s). Advantageously, this enhances paddlewheel mixing and reduces the likelihood of overexposure to UV.In some embodiments, the one or more induction raceway ponds in the second algal culture phasecomprise at least two induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, in each of the series of induction raceway ponds, the algae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, algae are harvested from the final induction pond(s). In some embodiments, the algae are green during the first algal culture phase. In some embodiments, the algae become beige or orange during the second algal culture phase. In some embodiments, the stress conditions that induce the algae to increase carbohydrateproduction comprise nutrient limitation, high salinity, high temperature, low temperature, decreasinglight exposure and / or increasing light exposure. In some embodiments, nutrient limitation comprises limitation of one or more of nitrogen, phosphorous and / or silicon. In some embodiments, the stress conditions that induce the algae to increase carbohydrateproduction comprise the presence of a low concentration of nitrogen (e.g. less than 10 μM nitrogen).In some embodiments, the stress conditions that induce the algae to increase carbohydrateproduction comprise the presence of a low concentration of phosphorus (e.g. less than 20 μMphosphorus). In some embodiments, the stress conditions that induce the algae to increasecarbohydrate production comprise the presence of a low concentration of silicon (e.g. less than 20 μMsilicon).In some embodiments, the carbohydrate is a phycocolloid. In some embodiments, the phycocolloidcomprises UVB and UVC-resistant phycocolloids. In some embodiments, the phycocolloid is a UVB-resistant phycocolloid. In some embodiments, the phycocolloid is a UVC-resistant phycocolloid.In some embodiments, the algal culture is diluted in each raceway pond in the first algal culture phase, and wherein pond volume for each pond in the first algal culture phase is modelled by the following equation: ^ V=^^^(^)^ ^V^ ∙ 2wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algal culture phase, and wherein pond volume for each pond in the second algal culture phase is modelled by the following equation: ^ V ^ ^= V ∙ 2 ^^(^)^ ^ wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond.In some embodiments, the algal growth rate during step (a) is at least 0.7d-1 (e.g.0.7-1.0 d-1) and / orwherein the algal growth rate at the end of step (b) is less than 0.6 d-1 (e.g.0.5 d-1).In some embodiments, the series of connected raceway ponds in the first algal culture phase is a linear series.In some embodiments, the series of connected raceway ponds in the first algal culture phasecomprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more stages of open raceway ponds.In some embodiments, one or more nutrient mineral acids are added during the first algal culturephase, optionally wherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.In some embodiments, the second algal culture phase is performed for at least four days (e.g.4-10days). Lipids In some embodiments, the HVP is a lipid. As used herein, the term “lipid” also encompasses fatty acids, sterols, monoglycerides, diglycerides, triglycerides and phospholipids. The invention provides a method for producing a lipid, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine lipid-producing microalgae ina first series of connected raceway ponds, arranged in stages, and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured under stress conditions that induce the algae to increase lipid production thereby inducing the algae to increase production of lipid; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b), and (d) an extraction phase, wherein the extraction phase comprises extracting lipid from the algae harvested in step (c).In some embodiments, upon transfer into each of the one or more induction raceway ponds, the algaeare cultured in water that is at least 10%, at least 15%, at least 20%, or at least 25% shallower than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, upon transfer into each of the one or more induction racewayponds, the algae are cultured in water that is 10-25% shallower than the water in which the algae arecultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for at least the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the mean photosynthetically active radiation (PAR) and UV light does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s). Advantageously, this enhances paddlewheel mixing and reduces the likelihood of overexposure to UV.In some embodiments, the one or more induction raceway ponds in the second algal culture phasecomprise at least two induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, in each of the series of induction raceway ponds, the algae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, algae are harvested from the final induction pond(s). In some embodiments, the algae are green during the first algal culture phase. In some embodiments, the algae become beige or orange during the second algal culture phase. In some embodiments, the stress conditions that induce the algae to increase lipid productioncomprise one or more of nutrient limitation, high salinity, high temperature, low temperature,decreasing light exposure and / or increasing light exposure. In some embodiments, nutrient limitation comprises limitation of one or more of nitrogen, phosphorous and / or silicon. In some embodiments, the stress conditions that induce the algae to increase lipid productioncomprise the presence of a low concentration of nitrogen (e.g. less than 10 μM nitrogen). In someembodiments, the stress conditions that induce the algae to increase lipid production comprise thepresence of a low concentration of phosphorus (e.g. less than 20 μM phosphorus). In someembodiments, the stress conditions that induce the algae to increase lipid production comprise thepresence of a low concentration of silicon (e.g. less than 20 μM silicon).In some embodiments, nutrient limitation comprises limitation of nitrogen. In some embodiments, the algal culture is diluted in each raceway pond in the first algal culture phase, and wherein pond volume for each pond in the first algal culture phase is modelled by the following equation: ^ V=^^^(^)^ ^V^ ∙ 2wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algal culture phase, and wherein pond volume for each pond in the second algal culture phase is modelled by the following equation: ^ V=^^^(^)^ ^V^ ∙ 2wherein V1is the final post-dilution pond volume, V0is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond.In some embodiments, the algal growth rate during step (a) is at least 0.7d-1 (e.g.0.7-1.0 d-1) and / orwherein the algal growth rate at the end of step (b) is less than 0.6 d-1 (e.g.0.5 d-1).In some embodiments, the series of connected raceway ponds in the first algal culture phase is a linear series.In some embodiments, the series of connected raceway ponds in the first algal culture phasecomprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more stages of open raceway ponds.In some embodiments, one or more nutrient mineral acids are added during the first algal culturephase, optionally wherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.In some embodiments, the concentration of nitrogen in step (b) is less than 10 μM.In some embodiments, the second algal culture phase is performed for at least four days (e.g.4-10days). In some embodiments, the fatty acid-producing microalgae is Thalassiosira weissflogii. Bioavailable minerals In some embodiments, the HVP is a bioavailable mineral. As used herein, the term “bioavailable mineral” encompasses naturally occurring, crystalline solids. In one embodiment, the bioavailable mineral is diatomaceous earth. Diatomaceous earths consist ofthe fossilised remains of diatom cell walls (frustules). Diatomaceous earths can be useful componentsin, for example, toothpaste, soil for potted plants. Diatomaceous earths can also be used as filtrationaids and thermal insulators, for example. A particularly useful application of diatomaceous earths is inthe stabilisation of anti-cancer drugs during delivery. This requires clean, and predictable particleshapes and sizes which diatoms are well suited to produce.The invention provides a method for producing a bioavailable mineral (e.g. diatomaceous earth),wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine bioavailable mineral-producing microalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), wherein the algae are cultured under stress conditions that induce the algae to increasebioavailable mineral production thereby inducing the algae to increase production of bioavailablemineral; (c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b), and (d) an extraction phase, wherein the extraction phase comprises extracting the bioavailable mineral(s) from the algaeharvested in step (c).In some embodiments, upon transfer into each of the one or more induction raceway ponds, the algaeare cultured in water that is at least 10%, at least 15%, at least 20%, or at least 25% shallower than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, upon transfer into each of the one or more induction racewayponds, the algae are cultured in water that is 10-25% shallower than the water in which the algae arecultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for at least the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are cultured in shallower water, for the first day following transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the mean photosynthetically active radiation (PAR) and UV light does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s). Advantageously, this enhances paddlewheel mixing and reduces the likelihood of overexposure to UV.In some embodiments, the one or more induction raceway ponds in the second algal culture phasecomprise at least two induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, in each of the series of induction raceway ponds, the algae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, algae are harvested from the final induction pond(s). In some embodiments, the algae are green during the first algal culture phase. In some embodiments, the algae become beige or orange during the second algal culture phase. In some embodiments, the stress conditions that induce the algae to increase bioavailable mineralproduction comprise one or more of nutrient limitation, high salinity, high temperature, lowtemperature, decreasing light exposure and / or increasing light exposure. In some embodiments, nutrient limitation comprises limitation of one or more of nitrogen, phosphorous and / or silicon. In some embodiments, the stress conditions that induce the algae to increase bioavailable mineralproduction comprise the presence of a low concentration of nitrogen (e.g. less than 10 μM nitrogen).In some embodiments, the stress conditions that induce the algae to increase bioavailable mineralproduction comprise the presence of a low concentration of phosphorus (e.g. less than 20 μMphosphorus). In some embodiments, the stress conditions that induce the algae to increasebioavailable mineral production comprise the presence of a low concentration of silicon (e.g. less than20 μM silicon). In some embodiments, the algal culture is diluted in each raceway pond in the first algal culture phase, and wherein pond volume for each pond in the first algal culture phase is modelled by the following equation: ^ V ^ ^= V^ ∙ 2^^(^)^ wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algal culture phase, and wherein pond volume for each pond in the second algal culture phase is modelled by the following equation: ^ V ^ ^^(^)^ ^= V^ ∙ 2wherein V1 is the final post-dilution pond volume, V0 is the pond volume of the preceding pond, and μ is the growth rate of the algae in the preceding pond.In some embodiments, the algal growth rate during step (a) is at least 0.7d-1 (e.g.0.7-1.0 d-1) and / orwherein the algal growth rate at the end of step (b) is less than 0.6 d-1 (e.g.0.5 d-1).In some embodiments, the series of connected raceway ponds in the first algal culture phase is a linear series.In some embodiments, the series of connected raceway ponds in the first algal culture phasecomprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more stages of open raceway ponds.In some embodiments, one or more nutrient mineral acids are added during the first algal culturephase, optionally wherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.In some embodiments, the concentration of nitrogen in step (b) is less than 10 μM.In some embodiments, the second algal culture phase is performed for at least four days (e.g.4-10days). The invention also provides a method for producing a fatty acid, wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine fatty acid-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition, (b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in step (a), Raceway ponds Land-based mariculture according to the invention comprises culturing algae in at least one raceway pond 100. Preferably the cultivation water for the at least one raceway pond 100 comprises seawater, but other types of water may be used, as discussed herein. A typical raceway pond is illustrated in Figure 1. Raceway pond 100 is stadium shaped (i.e.,a rectangle with semicircles at a pair of opposite ends), with a partial divide in the centre of the pond100 (i.e., along the longitudinal axis A) to create a circuit (i.e., channel 120) having two longitudinalchannel sections 120a, 120b which are joined at opposite ends of the raceway pond 100 by U-bend channel sections 120c, 120d. The stadium shape is defined by side wall 102. The partial divide is defined by divider 104. The side wall 102 and divider 104 may be formed of plastic covered andreinforced walls, fencing posts or earthen berms. Water and algae is retained in the raceway pond100 by the side wall 102 and the base of the pond (not shown).At one side of divider 104 (e.g., along a side wall 102) there may be a support structure that servesboth as an anchor for a paddlewheel 110 and to anchor the divider 104 between the longitudinal channel sections 120a, 120b. Paddlewheel 110 maintains the flow of water and algae around the circuit. The paddlewheel 110 is typically a variable speed paddlewheel.At the opposite ends of the raceway pond 100 (i.e., at the semicircles of the stadium shape), thechannel has U-bend channel sections 120c, 120d. Within the U-bend channel sections 120c, 120d, there are flow diverters 106 to ensure efficient flow throughout the raceway. In particular, flow diverters 106 act to maintain laminar flow of algae and water around the channel 120, especially at the U-bend channel sections 120c, 120d.The raceway pond 100 further comprises an inlet pipe 108 and a drainpipe 112. The inlet pipe 108may be connected to a gate-controlled sluice (not shown) for pond intake from either a seawatercanal and / or a previous pond. The drainpipe 112 facilitates pond discharge through a second gate-controlled sluice (not shown). The dilution rate of the algae in the raceway pond 100, which is the rateat which water is added to the algae (i.e., to dilute the algae), is determined by the position of thegate-controlled sluice of the inlet pipe 108 and / or the drainpipe 112. For instance, opening the gate-controlled sluice of the inlet pipe 108 and closing the gate-controlled sluice of the drainpipe 112increases the dilution rate. The dilution volume is the volume of water added to the raceway pond.In one embodiment, raceway pond 100 may be a covered raceway pond, which is a raceway pond 100 covered by a greenhouse (not shown). The primary purpose of the greenhouse is to protect the seed algae from being contaminated by windborne or bird-borne contaminants. Secondly the greenhouse is used to raise the temperature of the algal growth environment; both to increase the algal growth rate, and to inactivate competing or deleterious organisms that might otherwise contaminate the algae or foul the equipment. The greenhouse can also be used to selectively shade or change the illumination colour of the algae to induce a desirable physiological state by altering the wavelength of light. In one specific embodiment, every raceway pond 100 is covered by a greenhouse. Alternatively, raceway pond 100 may be an open raceway pond. An open raceway pond has no external cover, and as such is fully exposed to the ambient atmosphere, while a covered raceway pond (which may be fully or partially covered) allows partial or complete control of the temperature and light environment. Each raceway pond 100 is able to hold a certain volume of water and algae, depending on the depth,width and length of the raceway pond 100. In the context of the invention, volume of a raceway pondis defined as its capacity (i.e., the volume of fluid a raceway pond is capable of holding) rather thanthe volume of fluid actually held in the raceway pond at any given time. An increase in volume ofraceway pond 100 is achieved by increased width and / or length of the raceway pond. In a specificembodiment, raceway pond 100 increases in volume through increased width and length. Depth of the raceway pond 100 cannot be increased as easily since changing the depth affects algal solar irradiation. In a specific embodiment, raceway pond 100 has a width (perpendicular to axis A) to length (along axis A) size ratio of between 1:4 and 1:12, preferably 1:8. At this ratio, there is relatively low head loss at each paddlewheel 110 as the water circulates around the bends, favourable economy of the construction materials (straight walls are easier to build than the bends), the reduction of wind influence (wind fetch) as it blows across the pond (to prevent potentially unmixed zones). The width of approximately 30 metres per channel 120 also reduces meandering flow to maintain turbulent flow. Information regarding the application of computational fluid dynamics to raceway pond design can be found in Kusmayadi, 2020. In some embodiments, a plurality of raceway ponds 100 may be used in parallel to increase the collective volume of water and algae. The plurality of raceway ponds 100 may form a group. The group may comprise, for example, 2, 4, 6, 8, 10, 12, 14, 16, or 18 ponds. The inlet pipe 108 of each raceway pond 100 of the group may connected to a common seawater canal. Similarly, the drainpipe 112 of each raceway pond 100 of the group may connected to a common outlet. In one embodiment, a covered raceway pond (or group of covered raceway ponds) has volume ofbetween 50 l and 15,000,000 l, for example between 50 l and 50,000 l. In a particular embodiment, there is a series of covered raceway ponds, and the volume of covered raceway ponds in the series increases such that there is at least one pond in the series with a volume of (a) 50-1,000 l; at leastone covered raceway pond in the series with a volume of (b) 1001-30,000 l; and at least one pond inthe series with a volume of (c) 5,000 - 12,000,000 l. In one embodiment, these ponds are linked in alinear fashion, such that there is one pond at each stage in the series. In one embodiment, an open raceway pond (or group of open raceway ponds) has volume of between1,500,000 l and 3,000,000 l, in a further embodiment between 6,000,000 l and 15,000,000 l. In a stillfurther embodiment, the volume of the open raceway ponds in the series increases such that there isat least one open raceway pond in the series with a volume of (a) 360,000 – 720,000 l; at least onepond in the series with a volume of (b) 1,500,000 - 3,000,000 l; and at least one pond in the serieswith a volume of (c) 6,000,000 – 15,000,000 l.As mentioned, paddlewheel 110 may be used to maintain the flow of the algae and water around the raceway pond 100. This is energy efficient whilst ensuring thorough mixing and the exposure of the algae to relatively low shear. This enables effective exchange of gases within the ambient air with the algae growth medium. According to the species being cultivated, paddlewheel 100 may be used toachieve a different flow rate of algae and water within a raceway pond based on the physicalattributes of the paddlewheel (e.g., number of paddles, size of paddles) and / or the paddlewheelspeed (i.e., its rotational speed). The flow rate may be 0.1-0.5 m / minute, e.g., 0.1-0.4 m / minute or 0.1-0.3 m / minute. In one embodiment, each raceway pond 100 has one or more paddlewheels 110depending on the degree of agitation that is required. Preferably, each raceway pond 100 has one paddlewheel 110. The paddlewheel 110 may be positioned at any section of the raceway pond, but ispreferably positioned close to the inlet pipe 108 of a raceway pond (e.g., where the rectangle sectionof the stadium shape transitions to a semicircle). In one embodiment, one or more paddlewheels 110 maintain the flow of the algae and water within raceway pond 100 at a rate of about 0.1-0.5 m / minute, for example 0.1-0.4 m / minute, or 0.1-0.3 m / minute, or 0.15 m / minute, 0.2 m / minute, 0.25 m / minute. The depth of raceway pond 100 affects algal solar irradiation. Both light intensity and wavelengths are altered by increasing water depth. In general, far red, red and ultraviolet light are absorbed the most rapidly by the water and a blue and green light penetrate the furthest. However, algae in a shallower raceway pond 100 experiences greater light intensity and a greater proportion of red light than algae in a deeper raceway pond 100. In one embodiment, raceway pond 100 is between 0.05 m and 10 m deep, for example, 0.05 m, 0.10 m, 0.20 m, 0.30 m, 0.40 m, 0.50m, 0.60 m, 0.70 m, 0.80 m, 0.90 m,1m, 1.5m, 2 m, 3 m, 5 m, or 10 m deep. In one embodiment, a covered raceway pond is 0.1m – 1mdeep, for example 0.1m, 0.2m, 0.3m, 0.4m, or 0.5m deep. In one embodiment, an open raceway pondis 0.25 or 0.3 m – 1 m deep, for example 0.25 m, 0.3 – 0.4m, 0.5 m, 0.75 or 1 m deep. Preferably anopen raceway pond is less than 1 m deep. At this depth there is sufficient outgassing of O2 to help reduce oxidative stress, also at this depth there is sufficient exposure to dissolve atmospheric CO2. Raceway ponds known in the art are also usually uniform in depth. However, if the depth of racewaypond 100 is varied along the length of channel 120 (e.g., between longitudinal channel sections 120a,120b), a change in the flow rate results. Furthermore, the exposure of the algae to solar irradiation is varied, with algae in shallower areas of the raceway pond experiencing greater light intensity and a greater proportion of red light than algae in deeper areas. Photosynthetic output can be affected by the light ratio, especially at dawn and dusk, and as discussed herein the depth of the water alters the light wavelength ratio. Thus, in one embodiment, the depth of raceway pond 100 is non-uniform, resulting in a change in algal exposure to light both in terms of light intensity and light wavelength ratio and / or a change in the rate of gas exchange within the non-uniform section of the raceway pond. In one embodiment, the difference between the depth in longitudinal channel sections 120a, 120b is 0.05-1.0 m, for example 0.05 m, 0.10 m, 0.2 m, 0.3 m, 0.4 m, 0.5 m, 0.6 m, 0.7 m, 0.8 m, 0.9 m or 1.0 m. For example, one longitudinal channel section 120a is 0.2-0.5 m deep, while the second longitudinal channel section 120b is 0.8-1.0 m deep.As described herein, raceway pond 100 may be lined (not shown). In one embodiment, raceway pond100 is lined with an impermeable material. If seawater is used to culture the algae, a clay lining may be used to prevent saltwater intrusion onto the land. In one embodiment, a plastic waterproof lining is used instead of, or in addition to, a clay lining. In a particular embodiment, each raceway pond 100 islined with 10-20 cm of clay and a 2-5 cm, e.g., about 3 cm or specifically 8, 10 or 12 mm, robustsynthetic liner such as a black or white geomembrane. A white coating, for instance from titaniumoxide, may be provided over the black geomembrane.In one embodiment, the colour of the pond liners, or a coating of the pond liners, may be chosen toalter the wavelengths of light received by the algae as light reflects off the base of the ponds. The colour of the liner or coating may selectively decrease exposure of the algae to underwater red (630- 680 nm), far red (700-750 nm) and / or blue (400-450 nm) light. In one embodiment, the liner or coating selectively decreases the exposure to underwater red (630-680 nm), far red (700-750 nm) and / or blue (400-450 nm) light by 10-90%, 20-80%, 30-70%, or 40-60%. For example, the liner or coating may selectively absorb up to 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100% of the incident underwater red (630-680 nm), far red (700-750 nm) and / or blue (400-450 nm) light before the remaining light is reflected through the algal growth environment again. This is achieved by selecting the colour of the pond liner or coating based on the wavelengths that are to be absorbed.In a preferred embodiment, the lining or coating is white in order to reflect light off the base of thepond and maximise the light available for photosynthesis and encourage algal growth especially in thelow-density cultures and / or shallow cultures less than 30cm deep, where light will penetrate the depthof the medium. In some instances, black liners may be used to deliberately increase the temperatureof the cultivation medium.Different colours of lining or coating may be used to induce different physiological effects in the algae.For example, the lining or coating may be entirely red, blue or green. Alternatively, a single stage in the sequence of ponds can be coloured blue, for example at the point where the seed algal growth has been synchronised in the initial covered ponds, to reinforce cellular growth synchronisation and increase growth before cell division, just before the cells are introduced into the open growth ponds so that multiple divisions then occur in the growth pond. Similarly, the growth pond can be lined or coated in blue to stimulate the migration of chloroplasts to the outside of the cells, to promote maximum photosynthesis (Kraml & Hermann, 1991; Furukawa et al., 1998).As an alternative to coloured lining or coating, the side wall 102, base and other structural featureswithin the pond may be coloured. For instance, the side wall 102, base and other structural features may be white. The invention provides a raceway pond system, comprising: (a) a linear series of connected raceway ponds comprising a first stage comprising one or more covered raceway ponds and a second stage comprising one or more open raceway ponds; and (b) at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the linear series of connected raceway ponds, wherein each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds in the raceway pond system comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series. The invention further provides a raceway pond system for use in culturing marine microalgae, the raceway pond system comprising: (a) a linear series of connected raceway ponds comprising a first stage comprising one or more covered raceway ponds and a second stage comprising one or more open raceway ponds; and (b) at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the linear series of connected raceway ponds, wherein each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds in the raceway pond system comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series In some embodiments, the culture medium in the raceway pond system is seawater. Series of raceway ponds In one embodiment, the land-based mariculture of the invention comprises culturing algae in a series of connected raceway ponds, arranged in stages. Each of the raceway ponds in the series of connected raceway ponds may be based on raceway pond 100 of Figure 1. An example of an algal cultivation system 200 comprising a series of connected raceway ponds 210 arranged in stages 210A-230E is illustrated in Figure 2A. Figure 2B shows subsystem 200’ of system 200 in further detail. The stages 210A-230E of raceway ponds are connected in such a way so as to allow water and algae to pass directly between raceway ponds 100 in successive stages of the series. However, the connection between the stages 210A-230E of raceway ponds 100 can be closed and each stage 210A-230E of raceway ponds can be an isolated growth environment. The flow of waterand algae between successive stages in the series is unidirectional, i.e., the passage of algae andwater through the connected series of raceway ponds is one-way and algae and water are not re- circulated. In particular, in Figures 2A and 2B, there are three stages of covered raceway ponds, 210A, 210B and 210C and two stages of open raceway ponds 210D, 210E. However, other numbers of stages of covered raceway ponds and open raceway ponds may be used. In one specific embodiment of the invention the series of connected raceway ponds 210 comprises firstly, one or more stages ofcovered raceway ponds 210A-210C and secondly, one or more stages of open raceway ponds 210D-210E. The designations of “firstly” one or more stages of covered raceway ponds 210A-210C and“secondly” one or more stages of open raceway ponds 210D-210E indicate that within the series ofconnected ponds 210, the stages comprising covered raceway ponds 210A-210C will always come before the stages comprising open raceway ponds 210D-210E. Put another way, an open raceway210A-210C pond will never be succeeded by a covered raceway pond 210D-210E. Each stage 210A-210E of the series of connected raceway ponds 210 may comprise one or moreraceway ponds 100. Stages having a plurality (or group) of raceway ponds 100 use these ponds inparallel to increase the collective volume of water and algae that is throughput. The system 200 in Figures 2A and 2B, there are 16 ponds in each stage 210A-210E. However, the number of ponds does not have to be the same for each stage, as discussed further herein. In addition to the series of connected raceway ponds 210, system 200 comprises an intake pipeline 202 to transport water to the system, typically seawater from the ocean. Intake pipeline 202 feeds intake canal 208 which provides each of the raceway ponds in the series of connected raceway ponds 210 with water. Each raceway pond 100 has a connection to supply canal 208 at its respective inlet pipe 108. The supply canal 208 may be elevated so that gravity can be used to transport water to each of the raceway ponds 100 via the inlet pipe 108. The elevated supply canal filled from intake pipeline 202 with high-rate, low-head pumps. System 200 also comprises a harvest canal 212. Each raceway pond 100 in at least the final stage of the series of connected raceway ponds 210 has a connection to harvest canal 212 at its respective drain pipe 112. In stages other than the final stage, each raceway pond 100 is connected to the nextstage of raceway ponds via its respective drainpipe 112. The harvest canal 212 leads to a harvestingbuilding 214, where the algae is collected. The spent water is discharged through discharge pipeline 216. The discharge pipeline is at low elevation so that gravity moves water out of the harvesting building 214. In embodiments where the water is seawater, the intake pipeline 202 is upstream and as far needed from the discharge pipeline 216 to avoid reuptake of already spent seawater. Successive dilution in a semi-continuous cultivation manner, which maintains a low algal cell density, is beneficial for maintaining algae in the exponential growth phase. Successive dilution can be achieved in two ways. In the first way dilution is achieved by increasing the collective volume of the raceway pond(s) 100 in each stage 210A-210E of the series. This increase in collective volume can be achieved by increasing the volume of the individual raceway ponds in each successive stage 210A-210E of the series and / or by increasing the number of raceway ponds in each successive stage 210A-210E of the series. Thus, at each successive stage 210A-210E in the series of raceway ponds 210 of the present invention, each individual raceway pond has a volume greater than the volume of the individual raceway ponds in the preceding stage of the series; and / or each raceway pond is immediately succeeded by a greater number of raceway ponds, wherein the collective volume of the raceway ponds in any given stage exceeds the collective volume of the raceway ponds of the preceding stage. In the second way, dilution is achieved by increasing the volume of water in discrete steps to a maximum volume within a raceway pond 100, before the water and algae are transferred to the subsequent larger pond(s). For example, each pond may be initially filled to a first volume having afirst depth (e.g., 0.25 m) where the cells complete a growth cycle. When it is time to increase (e.g.,double) the volume of the water, to enable the cells to grow at a low standing stock with natural nutrients, the volume of water of the same pond is increased to a second volume having a seconddepth (e.g., 0.5 m). After the second growth cycle is complete within that pond, the total volume of thetwo division stages and the water is transferred to the next larger, subsequent pond. In other embodiments, the pond is filled in subsequent stages to 0.25 m, 0.5 m, 0.75 m and 1 m depth in four sequential ‘within-pond’ dilutions before it is transferred to the next larger pond. This ‘stacking’ of ponds is possible because of the relatively low standing stock (or low cellular concentration) of the algae in comparison to other cultivation systems. In other commercial algalgrowth systems (where cells are grown at a density resulting between 1,000 – 2,000 mg Chl a m-3),the high cell density results in gas exchange limitations and self-shading. However, in this method, neither of these are critical concerns, because the cell densities are significantly lower for the first 12- 16 growth cycles resulting in 50, 100, 200, 300, 400, 500 mg Chl a m-3). At these Chl a concentrations the ponds can be run without cell shading and the natural capacity of the seawater to absorb and buffer gases as well as exchange gases with the atmosphere enables cell growth. When algae and water are transferred from a raceway pond (covered or open) in one stage of the series to one or more raceway ponds (covered or open) in the next stage of the series, either thealgae and water are transferred to a single raceway pond with a greater volume, or the algae andwater are divided between a number of raceway ponds with a larger collective volume. Each transfer of the algae and water from one stage of the series to the next stage in the series thus involves dilution of the algae or is preceded by dilution of the algae in the current stage of ponds.In one embodiment, when the algae and water from one stage in the series (e.g., stage 210A) is usedto seed the raceway pond or raceway ponds of the next stage (e.g., stage 210B), it is transferred tothe raceway pond or raceway ponds of larger volume in the next stage of the series. Water is added to, or is already present in, the raceway ponds to be seeded, such that the final volume of fluid withinthe raceway ponds after seeding is equal to its capacity. This seeding step results in the algae beingdiluted and a low algal cell density can thus be maintained. Maintaining this constant low cell density of algae prevents the problems associated with traditional high-density algal culture, such as quorum sensing, biofilm formation and other (often unpredictable) algal stress responses. In an alternative embodiment, the algae are diluted prior to being transferred to the next stage of ponds. In this embodiment, fresh seawater is added to the current stage of ponds to dilute the algae. The successive dilution of the algae at each seeding step should not be taken to mean that the algal cell density at each stage in the series is successively reduced. Since the algae multiply rapidly, despite the successive dilutions at each seeding step the approximate cell density of algae in each stage of raceway ponds 210A-210E going through the series may increase, decrease or remain the same. In a specific embodiment, there are at least two stages of covered raceway ponds in the series of connected raceway ponds. For example, there may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 15 or 20 stages of covered raceway ponds. In one embodiment, there are 2-10 stages of covered raceway ponds, 4-8 stages of covered raceway ponds, or 5 stages of covered raceway ponds. In a preferred embodiment, the covered raceway ponds are preferably greenhouse covered and are connected in linearsuccession, wherein there is one covered raceway pond at each stage in the series of coveredraceway ponds. In this embodiment, each covered raceway pond is at least 2 times, for example 2 to 5 times, the volume of the covered raceway pond of the previous stage in the series. In a specific embodiment, each covered raceway pond is 2, 3, 4, or 5 times volume of the covered raceway pond of the previous stage in the series. In a preferred embodiment, each covered raceway pond is 5 timesvolume of the covered raceway pond of the previous stage in the series.In a further specific embodiment, there are at least two stages of open raceway ponds in the series of connected raceway ponds. For example, there may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20 or 25 stages of open raceway ponds. In one embodiment, there are 2-10 stages of open raceway ponds, 4-6 stages of open raceway ponds, or 5 stages of open raceway ponds. In one specific embodiment, there are more open raceway ponds than closed raceway ponds in the series. In some embodiments, the number of open raceway ponds in each stage is the same for each successive stage in the series. For example, the system 200 in Figure 2A and 2B has 16 ponds in the first stage of covered raceway ponds 210A, 16 ponds in the second stage of covered raceway ponds 210B which are larger than the ponds in the first stage of covered raceway ponds 210A, 16 ponds in the third stage of covered raceway ponds 210C which are larger than the ponds in the second stage of covered raceway ponds 210B. There is also 16 ponds in the first stage of open raceway ponds 210D (fourth stage overall) which are larger than the ponds in the third stage of covered raceway ponds 210C, and 16 ponds in the second stage of open raceway ponds 210E (fifth stage overall),which are larger than the ponds in the first stage of open raceway ponds 210E. Each subsequentpond has at least twice the capacity of the previous pond to hold the entirety of the volume of the previous pond and the equivalent volume of unused seawater. In a particular embodiment, the number of open raceway ponds in each stage increases at each successive stage in the series. In this embodiment, each open raceway pond is connected to two or more open raceway ponds in the next stage in the series, and the collective volume of each of the two or more open raceway pond exceeds the volume of the raceway pond in the preceding stage. Therefore, in this particular embodiment, the algae and water in one open raceway pond is diluted into two or more open raceway ponds when the algae and water are transferred between stages in the series. In a specific embodiment, the number of open raceway ponds in each stage of the series doubles. Therefore, in this embodiment the number of raceway ponds at each stage in the series increases exponentially. For example, the number of open raceway ponds at each stage increases as follows: 1, 2, 4, 8, 16, 32, 64, 128. In this embodiment, as the number of open raceway ponds at each stage increases, so does the volume of each individual raceway pond. In a preferred embodiment, the volume of the individual open raceway ponds in one stage is at least two times, preferably five times, the volume of the individual open raceway ponds in the previous stage. In an alternative embodiment, the volume of the individual open raceway ponds at each stage in the series remains the same, although the collective volume of the raceway ponds increases with each stage as the number of raceway ponds increases. The algae and water may be transferred between raceway ponds in successive stages of the series without any external force, for example it may be transferred under the influence of gravity. However, the algae and water will, on occasion when the local topography does not permit the use of gravity transfers, be pumped from one raceway pond to another, using any suitable pumping means that does not shear the cells. Figure 2A shows a particular layout for a series of connected raceway ponds 210. The advantage of this layout is that it efficiently hugs the coast along the edge of an ocean and enables each raceway pond to have at least one contact with the intake canal 208 and a discharge into the next larger and lower pond. This layout enables the water transfer within the entire pond system to rely on gravity feeds and requires a minimum of piping, while enabling easier maintenance of the ponds. This layout also takes advantage of the frequently encountered natural gradient along coastlines where distance from the shore commonly results in a slight increase in elevation. In some embodiments, the series comprises at least ten raceway ponds. In some embodiments, the series comprises at least fifteen raceway ponds. Seed ponds and photobioreactors In one embodiment, the first stage 210A of covered raceway ponds is seeded with algae cultivated in a photobioreactor (PBR) 204 or a seed pond (not shown). The amount of algae that is used for seeding the initial pond at first stage 210A is referred to as the inoculum density. A PBR 204 achieves a highly controlled environment within the reactor to maintain an uncontaminated stock culture. In order to prevent contamination with competing organisms, bacterial and viral infection, or predatory organisms that reduce the yield or availability of the seed algae, PBR 204 preferably uses sand and membrane filtered, pre-treated and decontaminated seawater. The exchange of gases is carefully controlled, for example by sparging or bubbling CO2 into the reactorand removing excess O2. The addition of nutrients and the removal of waste products is also carefullycontrolled. Preferably, PBR 204 operates in a sterile environment. A seed pond (not shown) is an open or closed pond, preferably a closed raceway pond, in which the growth conditions for the algae can be controlled. The seed pond is used to grow a population of algae sufficient to seed the first stage 210A of covered raceway ponds. In one embodiment, the first stage 210A of covered raceway ponds is seeded with algae from a PBR204 or seed pond in the early morning, e.g., from one hour before to two hours after dawn to enablethe algae to exploit their new growth environment, right after they have divided in the predawn hours, for example 1-2 hours before dawn. In a particular embodiment, the first stage 210A of coveredraceway ponds is seeded between 1-2 hours before and 1-2 hours after dawn, e.g., between 1 hourbefore and 2 hours after dawn, or in a specific embodiment when dawn is at 6 AM, the seeding occurs between the hours of 5 AM to 8 AM. Algae In some embodiments, a single species of algae is cultured. In some embodiments, more than one species of algae is cultured.In some embodiments, the marine HVP-producing microalgae are Cyanophyta, Glaucophyta,unicellular Rhodophyta, Heterokontophyta, Haptophyta, Dinophyta, Euglenophyta,Chlorarachniophyta or Chlorophyta (e.g., Prasinophyceae, Chlorophyceae, Ulvophyceae,Trebouxiophyceae or Charophyceae). In some such embodiments, the marine HVP-producingmicroalgae are Cyanophyta, Glaucophyta, unicellular Rhodophyta, Heterokontophyta, Haptophyta,Euglenophyta, Chlorarachniophyta or Chlorophyta (e.g., Prasinophyceae, Chlorophyceae,Ulvophyceae, Trebouxiophyceae or Charophyceae). In some embodiments, the marine HVP-producing microalgae are: (i) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema sp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., or(ii) Dunaliella sp..In some embodiments, the marine HVP-producing microalgae are Dunaliella sp. In some suchembodiments, the marine HVP-producing microalgae are Dunaliella salina.In some embodiments, the marine HVP-producing microalgae are Skeletonema sp. In some suchembodiments, the marine HVP-producing microalgae are Skeletonema pseudocostatum. In some embodiments, the algae comprise diatom-diazotroph assemblages (DDAs). In some embodiments, the algae comprise diatoms. In some embodiments, the algae comprise bloom-forming algae. In some embodiments, the algae comprise r-strategist algae. DDAs In some embodiments, the algae that are cultured in the method of the invention comprise “diatom-diazotroph assemblages (DDAs)”. As used herein, “diatom-diazotroph assemblages (DDAs)” refers to symbioses between diatoms and diazotrophic prokaryotes. In these associations, the diazotrophic prokaryote captures or ‘fixes’ atmospheric N2 and makes it bioavailable to the diatom symbiont. In some embodiments, the DDAs comprise diazotrophic cyanobacteria.Diazotrophic cyanobacteria like Richelia, Calothrix and other unicellular species similar in morphologyto free-living diazotroph Crocosphaera, thrive by forming symbiotic relationships with diatoms likeHemiaulus, Rhizosolenia, Chaetoceros and Climacodium (Mutalipassi et al., 2021; Hilton 2014).Some of these associations, like Calothrix or the novel unicellular cyanobacteria CandidatusAtelocyanobacterium thalassa (UCYN-A) (Tuo et al., 2017) associate with unicellular algaeepiphytically (or on the outside of cells). Other diazotrophic symbionts are intracellular such as Richelia. In some embodiments, the DDAs comprise marine diazotrophic cyanobacteria. In some embodiments, the marine diazotrophic cyanobacteria are selected from Richelia sp., Calothrix sp., Crocosphaera sp. and Candidatus Atelocynaobacterium Thalassa. In some embodiments, the marine diazotrophic cyanobacteria are Richelia sp. In some embodiments, the marine diazotrophiccyanobacteria are Calothrix sp. In some embodiments, the marine diazotrophic cyanobacteria areCrocosphaera sp. In some embodiments, the marine diazotrophic cyanobacteria are CandidatusAtelocynaobacterium Thalassa.In some embodiments, the DDAs comprise Richelia sp., optionally R. intracellularis.In some embodiments, the DDAs comprise Calothrix sp., optionally one or more of C. adscendens, C. atricha, C. braunii, C. breviarticulata, C. caespitora, C. confervicola, C. crustacea, C. donnelli, C. elenkinii, C. epiphytica, C. fusca, C. juliana, C. parasitica, C. parietina, C. pilosa, C. pulvinata, C. scopulorum, C. scytonemicola, C. simulans, C. solitaria, C. stagnalis, C. stellaris, and C. thermalis. In some embodiments, the DDAs comprise Crocosphaera sp., optionally C. watsonii. In some embodiments, the DDAs comprise one or more of the following diatoms: Hemiaulus sp., Skeletonema sp., Rhizosolenia sp., Climacodium sp. and Chaetoceros sp. In some embodiments, the DDAs comprise Hemiaulus sp., optionally H. hauckii, H. indicus,H. membranaceus, or H. sinensis. In some embodiments, the DDAs comprise Skeletonema sp., optionally S. barbadense, S. costatum,S. cylindraceum, S. mediterraneum, S. punctatum, S. tropicum, or S. pseudocostatum.In some embodiments, the DDAs comprise Rhizosolenia sp., optionally R. alata, R. acuminata, R.antarctica, R. antennata, R. bergonii, R. clevei, R. curvata, R. cylindrus, R. delicatula, R. minima, R.pugens, R. robusta, R. rothii, R. stricta, or R. styliformis.In some embodiments, the DDAs comprise Climacodium sp., optionally C. biconcavum orC. frauenfeldianum.In some embodiments, the DDAs comprise Chaetoceros sp., optionally C. socialis, C. debilis, C.curvisetus, C. muelleri, C. calcitrans, or C. didymus. In some embodiments, the DDAs comprise an assemblage of marine diazotrophic cyanobacteria and diatoms. In some embodiments, the marine diazotrophic cyanobacteria are selected from Richelia sp., Calothrix sp., Crocosphaera sp. and Candidatus Atelocynaobacterium Thalassa, and the diatoms are selected from Hemiaulus sp., Skeletonema sp., Rhizosolenia sp., Climacodium sp. and Chaetoceros sp. In some embodiments, the DDAs comprise an assemblage of Richelia sp. and Hemiaulas sp. Oligotrophic conditions are nutrient poor conditions. For example, oligotrophic conditions may comprise low concentrations of bioavailable nitrogen and phosphorus. These oligotrophic conditions are preferably present within a raceway pond or a series of connected raceway ponds.In some instances, the oligotrophic conditions comprise less than 20 µM (e.g., 10 µM) phosphorusand less than 40 µM (e.g., 20 µM) nitrogen. Accordingly, in some embodiments of the invention, thealgae comprise DDAs, and nutrient mineral acids are added to a total concentration of less than 60µM (e.g., less than 30 µM). In some such embodiments, phosphorus-containing acid (e.g., H3PO4) isadded in the growth phase to a final concentration of less than 20 µM (e.g., less than 10 µM). In somesuch embodiments, nitrogen-containing acid (e.g., HNO3) is added in the growth phase to a finalconcentration of less than 40 µM (e.g., less than 20 µM).Diatoms In some embodiments, the algae that are cultured in the method of the invention comprise diatoms. In some embodiments, the diatoms are fast-growing diatoms. In some embodiments, the diatoms are bloom-forming diatoms. For example, diatoms that have(i) the ability to grow exponentially or (ii) a cell division rate that exceeds one division per day.In some embodiments, the diatoms are selected from Skeletonema sp., Chaetoceros sp.,Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. and Nitzschia sp.In some embodiments, the diatoms are Skeletonema sp., optionally S. barbadense, S. costatum, S.cylindraceum, S. mediterraneum, S. punctatum, S. tropicum, or S. pseudocostatum.In some embodiments, the diatoms are Chaetoceros sp., optionally C. socialis, C. debilis, C.curvisetus, C. muelleri, C. calcitrans, or C. didymus.In some embodiments, the diatoms are Thalassiosira sp., optionally T. pseudonana, or T. symmetrica.In some embodiments, the diatoms are Coscinodiscus sp., optionally C. wailesii.In some embodiments, the diatoms are Navicula sp., optionally N. pelliculosa, N. incerta, N. oblonga,N. salinicola, N. ramosissima, N. minima, N. cryptocephala, or N. trivialis.In some embodiments, the diatoms are Synedra sp., optionally S. capitata, S. famelica, S. radians, S.rumpens, or S. ulna.In some embodiments, the diatoms are Nitzschia sp., optionally N. frigida, N. acicularis, N. amphibia,or N. angustata. Bloom-forming algae In some embodiments, the algae that are cultured in the method of the invention comprise bloom-forming algae. In some embodiments, the bloom-forming algae are Dunaliella sp., optionally D. salina. In some embodiments, the bloom-forming algae are Rhodomonas sp., optionally R. minuta. In some embodiments, the bloom-forming algae are Chaetoceros sp., optionally C. socialis, C. debilis, C. curvisetus, C. muelleri, C. calcitrans, C. didymus, or C. convolutus. R-strategist algae In ecology, r-strategist organisms are characterised by their high growth rates in less-crowded ecological niches. They are considered opportunistic organisms and thrive in more unstable and unpredictable environments due to their ability to reproduce rapidly. Conversely, K-strategist organisms are characterised by a much lower growth rate in an ecological niche which is close to or at the carrying capacity for that organism. They exist in an equilibrium and thrive in more stable or predictable environments, competing for limited resources. The method of the invention described herein represents a controlled, stable and predictable environment in which algae are cultured. Algae often fit the description of r-strategist organisms, displaying rapid growth rates in often unstable and unpredictable environments. Therefore, it is surprising to find that algae grow particularly well in the tightly controlled, highly predictable conditions of the method of the invention described herein. In some embodiments, the algae that are cultured in the method of the invention comprise r-strategist algae. In some embodiments, the r-strategist algae are cultured in a K-strategist environment. In some embodiments, the r-strategist algae are cultured under K-strategist conditions. In some embodiments, K-strategist conditions comprise one or more of a stable temperature, a stable salinity level, a stable humidity and a stable duration of sunlight. Photosynthetically active radiation (PAR) As used herein, the term “photosynthetically active radiation” (PAR) refers to the range of wavelengths of light required for photosynthesis in algae. Typically, PAR is between 400 nm and 700 nm.As used herein, the term “light photoinhibition parameter” (Ekβ) refers to a light level at which thegrowth rate of the algae begins to decrease.In a preferred embodiment, the mean photosynthetically active radiation (PAR) and UV light in eachraceway pond and / or induction raceway pond does not exceed the light photoinhibition parameter (Ekβ) of the algae. First algal culture phaseThe first algal culture phase comprises culturing marine HVP-producing microalgae in a series ofconnected raceway ponds, arranged in stages, wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition. As used herein, “nutrient mineral acid” refers to an inorganic acid in which the conjugate baseprovides nourishment for algae (e.g., the conjugate base is used by algae to survive and grow).In some embodiments, one or more nutrient mineral acids are added in the first algal culture phase. In some embodiments, the one or more nutrient mineral acids are selected from aphosphorus-containing acid, silicon-containing acid, and nitrogen-containing acid.In some embodiments, a phosphorus-containing acid is added in the first algal culture phase. In general, all algae assimilate phosphorus for survival and growth. Therefore, phosphorus-containing acids are nutritious for any algal species. In some embodiments, the nutrient mineral acid is a phosphorus oxoacid. In some embodiments, the nutrient mineral acid has a phosphate anion as a conjugate base. In some embodiments, the nutrient mineral acid is a phosphoric acid. In some embodiments, the phosphoric acid has the chemical formula H3PO4. In preferred embodiments, the phosphorus-containing acid is phosphoric acid (H3PO4).In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the first algal culturephase to a final concentration of at least 0.15 μM, at least 0.5 μM, at least 1.0 μM, at least 1.5 μM, at least 2.0 μM, at least 5.0 μM, at least 10 μM, or at least 15 μM. In some embodiments,phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a finalconcentration of 0.15-15 μM (e.g., 0.5-4.5 μM, such as 1-2 μM). In some embodiments,phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a finalconcentration of between 0.1 μM and 2.0 μM, between 0.5 μM and 2.0 μM, or between 1.0 μM and2.0 μM. In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the first algalculture phase to a final concentration of 1.5 μM. The concentration of phosphorus-containing acid that is added can be influenced by the algal celldensity. Accordingly, in some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in thefirst algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 5 to (ii) number of thousand algal cells per mlmultiplied by 25. In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the firstalgal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 7 to (ii) the number of thousand algal cells per mlmultiplied by 15. In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the firstalgal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 10 to (ii) the number of thousand algal cells per ml multiplied by 13.In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the first algal culturephase to a final nanomolar concentration calculated as being at least the number of thousand algalcells per ml multiplied by 5. In some embodiments, phosphorus-containing acid (e.g., H3PO4) is addedin the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 10. In some embodiments, phosphorus-containingacid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentrationcalculated as being at least the number of thousand algal cells per ml multiplied by 12. In someembodiments, phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to afinal nanomolar concentration calculated as being at least the number of thousand algal cells per mlmultiplied by 15. In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the firstalgal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 20. In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 25.In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the first algal culturephase to a final nanomolar concentration calculated as the number of thousand algal cells per mlmultiplied by 5. In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the firstalgal culture phase to a final nanomolar concentration calculated as the number of thousand algalcells per ml multiplied by 10. In some embodiments, phosphorus-containing acid (e.g., H3PO4) isadded in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 12. In some embodiments, phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 15. In some embodiments, phosphorus-containingacid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentrationcalculated as the number of thousand algal cells per ml multiplied by 20. In some embodiments,phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as the number of thousand algal cells per ml multiplied by 25. In some embodiments, the phosphorous-containing conjugate base to the phosphorous-containingacid (e.g., H3PO4) is added in the first algal culture phase to a final concentration of at least 0.15 μM,at least 0.5 μM, at least 1.0 μM, at least 1.5 μM, at least 2.0 μM, at least 5.0 μM, at least 10 μM, or at least 15 μM. In some embodiments, the phosphorous-containing conjugate base to the phosphorous-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final concentration of0.15-15 μM (e.g., 0.5-4.5 μM, such as 1-2 μM). In some embodiments, the phosphorous-containingconjugate base to the phosphorous-containing acid (e.g., H3PO4) is added in the first algal culturephase to a final concentration of between 0.1 μM and 2.0 μM, between 0.5 μM and 2.0 μM, or between 1.0 μM and 2.0 μM. In some embodiments, the phosphorous-containing conjugate base tothe phosphorous-containing acid (e.g., H3PO4) is added in the first algal culture phase to a finalconcentration of 1.5 μM. In some embodiments, the phosphorous-containing conjugate base to the phosphorus-containing acid(e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentration calculated asbeing within the range of: (i) number of thousand algal cells per ml multiplied by 5 to (ii) number of thousand algal cells per ml multiplied by 25. In some embodiments, the phosphorous-containingconjugate base to the phosphorus-containing acid (e.g., H3PO4) is added in the first algal culturephase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 7 to (ii) the number of thousand algal cells per ml multiplied by 15. In some embodiments, the phosphorous-containing conjugate base to the phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 10 to (ii) the number of thousand algal cells per ml multiplied by 13. In some embodiments, the phosphorous-containing conjugate base to the phosphorus-containing acid(e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentration calculated asbeing at least the number of thousand algal cells per ml multiplied by 5. In some embodiments, thephosphorous-containing conjugate base to the phosphorus-containing acid (e.g., H3PO4) is added inthe first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 10. In some embodiments, the phosphorous-containingconjugate base to the phosphorus-containing acid (e.g., H3PO4) is added in the first algal culturephase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 12. In some embodiments, the phosphorous-containing conjugate base tothe phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a finalnanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 15. In some embodiments, the phosphorous-containing conjugate base to thephosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as being at least the number of thousand algal cells per ml multiplied by 20. In some embodiments, the phosphorous-containing conjugate base to the phosphorus-containing acid(e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentration calculated asbeing at least the number of thousand algal cells per ml multiplied by 25. In some embodiments, the phosphorous-containing conjugate base to the phosphorus-containing acid(e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentration calculated asthe number of thousand algal cells per ml multiplied by 5. In some embodiments, the phosphorous-containing conjugate base to the phosphorus-containing acid (e.g., H3PO4) is added in the first algalculture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 10. In some embodiments, the phosphorous-containing conjugate base to thephosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as the number of thousand algal cells per ml multiplied by 12. In some embodiments, the phosphorous-containing conjugate base to the phosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 15. In some embodiments, the phosphorous-containing conjugate base to the phosphorus-containing acid (e.g., H3PO4) is added in the first algalculture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 20. In some embodiments, the phosphorous-containing conjugate base to thephosphorus-containing acid (e.g., H3PO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as the number of thousand algal cells per ml multiplied by 25. In some embodiments, phosphorous is added in the first algal culture phase to a final concentration of at least 0.15 μM, at least 0.5 μM, at least 1.0 μM, at least 1.5 μM, at least 2.0 μM, at least 5.0 μM, at least 10 μM, or at least 15 μM. In some embodiments, phosphorous is is added in the first algalculture phase to a final concentration of 0.15-15 μM (e.g., 0.5-4.5 μM, such as 1-2 μM). In someembodiments, phosphorous is added in the first algal culture phase to a final concentration of between 0.1 μM and 2.0 μM, between 0.5 μM and 2.0 μM, or between 1.0 μM and 2.0 μM. In some embodiments, phosphorous is added in the first algal culture phase to a final concentration of 1.5 μM. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 5 to (ii) number of thousand algal cells per ml multiplied by 25. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated asbeing within the range of: (i) the number of thousand algal cells per ml multiplied by 7 to (ii) thenumber of thousand algal cells per ml multiplied by 15. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 10 to (ii) the number of thousand algal cells per ml multiplied by 13. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 5. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 10. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 12. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 15. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 20. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 25. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 5. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 10. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 12. In some embodiments, phosphorus isadded in the first algal culture phase to a final nanomolar concentration calculated as the number ofthousand algal cells per ml multiplied by 15. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 20. In some embodiments, phosphorus is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 25. In some embodiments, a silicon-containing acid is added in the first algal culture phase. Some algalspecies (e.g., diatoms) assimilate silicon as a component of their cell walls. Therefore,silicon-containing acids are nutritious for algal species with silica cell wells (e.g., diatoms). In someembodiments, the nutrient mineral acid has a silicate anion as a conjugate base. In some embodiments, the nutrient mineral acid is a silicic acid. In some embodiments, the nutrient mineral acid is orthosilicic acid, metasilicic acid, pyrosilicic acid or disilicic acid. In preferred embodiments, the silicon-containing acid is orthosilicic acid (H4SiO4).In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase toa final concentration of at least 0.3 μM, at least 0.5 μM, at least 1.0 μM, at least 1.5 μM, at least 2.0 μM, at least 5.0 μM, at least 10 μM, at least 15 μM, or at least 30 μM. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final concentration of 0.3-30μM (e.g., 1-9 μM, such as 2-4 μM). In some embodiments, silicon-containing acid (e.g., H4SiO4) isadded in the first algal culture phase to a final concentration of between 0.3 μM and 5.0 μM, between0.5 μM and 5 μM, between 1.0 μM and 5.0 μM, between 1.5 μM and 5.0 μM, between 2.0 μM and 5.0 μM, between 2.5 μM and 5.0 μM, between 2.5 μM and 4.5 μM, between 2.5 μM and 4.0 μM orbetween 2.5 μM and 3.5 μM. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added inthe first algal culture phase to a final concentration of 3 μM.The concentration of silicon-containing acid (e.g., H4SiO4) that is added can be influenced by the algalcell density. Accordingly, in some embodiments, silicon-containing acid (e.g., H4SiO4) is added in thefirst algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 5 to (ii) number of thousand algal cells per mlmultiplied by 50. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algalculture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 15 to (ii) the number of thousand algal cells per mlmultiplied by 35. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algalculture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 20 to (ii) the number of thousand algal cells per mlmultiplied by 30. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algalculture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 22 to (ii) the number of thousand algal cells per ml multiplied by 26.In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase toa final nanomolar concentration calculated as being at least the number of thousand algal cells per mlmultiplied by 5. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algalculture phase to a final nanomolar concentration calculated as being at least the number of thousandalgal cells per ml multiplied by 10. In some embodiments, silicon-containing acid (e.g., H4SiO4) isadded in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 15. In some embodiments, silicon-containingacid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentrationcalculated as being at least the number of thousand algal cells per ml multiplied by 20. In someembodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a finalnanomolar concentration calculated as being at least the number of thousand algal cells per mlmultiplied by 25. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algalculture phase to a final nanomolar concentration calculated as being at least the number of thousandalgal cells per ml multiplied by 30. In some embodiments, silicon-containing acid (e.g., H4SiO4) isadded in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 40. In some embodiments, silicon-containingacid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentrationcalculated as being at least the number of thousand algal cells per ml multiplied by 50.In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase toa final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by5. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phaseto a final nanomolar concentration calculated as the number of thousand algal cells per ml multipliedby 10. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algal culturephase to a final nanomolar concentration calculated as the number of thousand algal cells per mlmultiplied by 15. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algalculture phase to a final nanomolar concentration calculated as the number of thousand algal cells perml multiplied by 20. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the firstalgal culture phase to a final nanomolar concentration calculated as the number of thousand algalcells per ml multiplied by 25. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added inthe first algal culture phase to a final nanomolar concentration calculated as the number of thousandalgal cells per ml multiplied by 30. In some embodiments, silicon-containing acid (e.g., H4SiO4) isadded in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 40. In some embodiments, silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 50. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final concentration of at least 0.15 μM, at least 0.5 μM, at least 1.0 μM, at least 1.5 μM, at least 2.0 μM, at least 5.0 μM, at least 10 μM, or at least 15 μM. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g.,H4SiO4) is added in the first algal culture phase to a final concentration of 0.15-15 μM (e.g., 0.5-4.5μM, such as 1-2 μM). In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final concentration ofbetween 0.1 μM and 2.0 μM, between 0.5 μM and 2.0 μM, or between 1.0 μM and 2.0 μM. In some embodiments, the final concentration of the silicon-containing conjugate base to the silicon-containingacid (e.g., H4SiO4) is added in the first algal culture phase to a final concentration of 1.5 μM.In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 5 to (ii) number of thousand algal cells per ml multiplied by 50. In some embodiments, the silicon-containing conjugate base to thesilicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 15 to (ii) the number of thousand algal cells per ml multiplied by 35. In someembodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) isadded in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 20 to (ii) the number of thousand algal cells per ml multiplied by 30. In some embodiments, the silicon-containing conjugate base to thesilicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 22 to (ii) the number of thousand algal cells per ml multiplied by 26. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 5. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culturephase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 10. In some embodiments, the silicon-containing conjugate base to thesilicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as being at least the number of thousand algal cells per ml multiplied by 15. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 20. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culturephase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 25. In some embodiments, the silicon-containing conjugate base to thesilicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolarconcentration calculated as being at least the number of thousand algal cells per ml multiplied by 30. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 40. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culturephase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 50. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 5. In some embodiments, the silicon-containingconjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase toa final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 10. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 15. In some embodiments, the silicon-containingconjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase toa final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 20. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 25. In some embodiments, the silicon-containingconjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase toa final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 30. In some embodiments, the silicon-containing conjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 40. In some embodiments, the silicon-containingconjugate base to the silicon-containing acid (e.g., H4SiO4) is added in the first algal culture phase toa final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 50. In some embodiments, silicon is added in the first algal culture phase to a final concentration of at least 0.15 μM, at least 0.5 μM, at least 1.0 μM, at least 1.5 μM, at least 2.0 μM, at least 5.0 μM, at least 10 μM, or at least 15 μM. In some embodiments, silicon is added in the first algal culture phaseto a final concentration of 0.15-15 μM (e.g., 0.5-4.5 μM, such as 1-2 μM). In some embodiments,silicon is added in the first algal culture phase to a final concentration of between 0.1 μM and 2.0 μM,between 0.5 μM and 2.0 μM, or between 1.0 μM and 2.0 μM. In some embodiments, silicon is addedin the first algal culture phase to a final concentration of 1.5 μM. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 5 to (ii) number of thousand algal cells per ml multiplied by 50. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 15 to (ii) the number of thousand algal cells per ml multiplied by 35. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 20 to (ii) the number of thousand algal cells per ml multiplied by 30. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 22 to (ii) the number of thousand algal cells per ml multiplied by 26. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 5. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 10. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 15. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 20. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 25. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 30. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 40. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 50. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 5. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 10. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 15. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 20. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 25. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 30. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 40. In some embodiments, silicon is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 50. In some embodiments, a nitrogen-containing acid is added in the first algal culture phase.Nitrogen-fixing algae (e.g., diatom-diazotroph assemblages) have a reduced requirement forassimilating nitrogen from the culture medium. Other algal species typically have a much greater need for nitrogen assimilation than for phosphorus assimilation from the culture medium. The average nitrogen to phosphorus ratio in algal biomass is 16:1. In some embodiments, the nutrient mineral acid is a nitrogen acid. In some embodiments, the nutrient mineral acid has a nitrate anion as a conjugate base. In some embodiments, the nutrient mineral acid is nitric acid, nitrous acid or hyponitrous acid. In preferred embodiments, the nitrogen-containing acid is nitric acid (HNO3).In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phaseto a final concentration of at least 8 μM, at least 15 μM, at least 30 μM, at least 50 μM, at least 80 μM,at least 100 μM, at least 200 μM, at least 500 μM, or at least 800 μM. In some embodiments,nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final concentrationof 8-800 μM (e.g., 20-320 μM, such as 60-100 μM). In some embodiments, nitrogen-containing acid(e.g., HNO3) is added in the first algal culture phase to a final concentration of between 50 μM and100 μM, between 60 μM and 100 μM, between 70 μM and 100 μM, between 80 μM and 100 μM orbetween 80 μM and 90 μM. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added inthe first algal culture phase to a final concentration of 80 μM.The concentration of nitrogen-containing acid (e.g., HNO3) that is added can be influenced by thealgal cell density. Accordingly, in some embodiments, nitrogen-containing acid (e.g., HNO3) is addedin the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 50 to (ii) number of thousand algal cells perml multiplied by 5000. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in thefirst algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 200 to (ii) the number of thousand algal cellsper ml multiplied by 1500. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added inthe first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 400 to (ii) the number of thousand algalcells per ml multiplied by 800. In some embodiments, nitrogen-containing acid (e.g., HNO3) is addedin the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 600 to (ii) the number of thousand algal cells per ml multiplied by 700.In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phaseto a final nanomolar concentration calculated as being at least the number of thousand algal cells perml multiplied by 50. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the firstalgal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 100. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 200. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentrationcalculated as being at least the number of thousand algal cells per ml multiplied by 400. In someembodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a finalnanomolar concentration calculated as being at least the number of thousand algal cells per mlmultiplied by 500. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the firstalgal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 600. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 700. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentrationcalculated as being at least the number of thousand algal cells per ml multiplied by 1000. In someembodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a finalnanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 2000.In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phaseto a final nanomolar concentration calculated as the number of thousand algal cells per ml multipliedby 50. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per mlmultiplied by 100. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the firstalgal culture phase to a final nanomolar concentration calculated as the number of thousand algalcells per ml multiplied by 200. In some embodiments, nitrogen-containing acid (e.g., HNO3) is addedin the first algal culture phase to a final nanomolar concentration calculated as the number ofthousand algal cells per ml multiplied by 500. In some embodiments, nitrogen-containing acid (e.g.,HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as thenumber of thousand algal cells per ml multiplied by 600. In some embodiments, nitrogen-containingacid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculatedas the number of thousand algal cells per ml multiplied by 650. In some embodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentrationcalculated as the number of thousand algal cells per ml multiplied by 700. In some embodiments,nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolarconcentration calculated as the number of thousand algal cells per ml multiplied by 1000. In someembodiments, nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a finalnanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 2000. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final concentration of at least 8 μM, at least 15 μM,at least 30 μM, at least 50 μM, at least 80 μM, at least 100 μM, at least 200 μM, at least 500 μM, or atleast 800 μM. In some embodiments, the nitrogen-containing conjugate base to thenitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final concentrationof 8-800 μM (e.g., 20-320 μM, such as 60-100 μM). In some embodiments, the nitrogen-containingconjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase toa final concentration of between 50 μM and 100 μM, between 60 μM and 100 μM, between 70 μM and 100 μM, between 80 μM and 100 μM or between 80 μM and 90 μM. In some embodiments, thenitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the firstalgal culture phase to a final concentration of 80 μM. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 50 to (ii) number of thousand algal cells per ml multiplied by 5000. In some embodiments, the nitrogen-containingconjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase toa final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 200 to (ii) the number of thousand algal cells per ml multiplied by 1500. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 400 to (ii) the number of thousand algal cells per ml multiplied by 800. In some embodiments, the nitrogen-containingconjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase toa final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 600 to (ii) the number of thousand algal cells per ml multiplied by 700. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 50. In some embodiments, thenitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the firstalgal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 100. In some embodiments, the nitrogen-containingconjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase toa final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 200. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentrationcalculated as being at least the number of thousand algal cells per ml multiplied by 400. In someembodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) isadded in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 500. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algalculture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 600. In some embodiments, the nitrogen-containing conjugate base tothe nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolarconcentration calculated as being at least the number of thousand algal cells per ml multiplied by 700. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 1000. In some embodiments, thenitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the firstalgal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 2000. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 50. In some embodiments, the nitrogen-containingconjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase toa final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by100. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid(e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentration calculated asthe number of thousand algal cells per ml multiplied by 200. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algalculture phase to a final nanomolar concentration calculated as the number of thousand algal cells perml multiplied by 500. In some embodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolar concentrationcalculated as the number of thousand algal cells per ml multiplied by 600. In some embodiments, thenitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the firstalgal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 650. In some embodiments, the nitrogen-containing conjugate base to thenitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase to a final nanomolarconcentration calculated as the number of thousand algal cells per ml multiplied by 700. In someembodiments, the nitrogen-containing conjugate base to the nitrogen-containing acid (e.g., HNO3) isadded in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 1000. In some embodiments, the nitrogen-containingconjugate base to the nitrogen-containing acid (e.g., HNO3) is added in the first algal culture phase toa final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 2000. In some embodiments, nitrogen is added in the first algal culture phase to a final concentration of atleast 8 μM, at least 15 μM, at least 30 μM, at least 50 μM, at least 80 μM, at least 100 μM, at least200 μM, at least 500 μM, or at least 800 μM. In some embodiments, nitrogen is added in the first algalculture phase to a final concentration of 8-800 μM (e.g., 20-320 μM, such as 60-100 μM). In someembodiments, nitrogen is added in the first algal culture phase to a final concentration of between 50 μM and 100 μM, between 60 μM and 100 μM, between 70 μM and 100 μM, between 80 μM and 100 μM or between 80 μM and 90 μM. In some embodiments, nitrogen is added in the first algal culture phase to a final concentration of 80 μM. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 50 to (ii) number of thousand algal cells per ml multiplied by 5000. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 200 to (ii) the number of thousand algal cells per ml multiplied by 1500. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 400 to (ii) the number of thousand algal cells per ml multiplied by 800. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 600 to (ii) the number of thousand algal cells per ml multiplied by 700. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 50. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 100. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 200. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 400. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 500. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 600. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 700. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 1000. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as being at least the number of thousand algal cells per ml multiplied by 2000. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 50. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 100. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 200. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 500. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 600. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 650. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 700. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 1000. In some embodiments, nitrogen is added in the first algal culture phase to a final nanomolar concentration calculated as the number of thousand algal cells per ml multiplied by 2000. In some embodiments, one or more, two or more, three or more, four or more, or five or more nutrient mineral acids are added in the first algal culture phase.In some embodiments, the algae are diatoms, and a phosphorus-containing acid (e.g., H3PO4) asilicon-containing acid (H4SiO4), and a nitrogen-containing acid (e.g., HNO3) are added in the firstalgal culture phase. In some embodiments, the algae are diatom-diazotroph assemblages, and a phosphorus-containingacid (e.g., H3PO4) and a silicon-containing acid (H4SiO4) are added in the first algal culture phase.In some embodiments, the algae are bloom-forming algae, and a phosphorus-containing acid (e.g.,H3PO4) and a nitrogen-containing acid (e.g., HNO3) are added in the first algal culture phase.In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is at least 5 μM, at least 10 μM, at least 25 μM, at least 50 μM, at least 85 μM, at least 150 μM, at least 300 μM, at least 500 μM, or at least 850 μM. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is 5-850 μM(e.g., 25-150 μM, such as 80-90 μM). In some embodiments, the final concentration of total nutrientmineral acid(s) after addition of nutrient mineral acid(s) is between 50 and 100 μM, between 60 and 100 μM, between 70 and 100 μM, between 80 and 100 μM or between 80 and 90 μM. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being within the range of: (i) number of thousand algal cells per ml multiplied by 50 to (ii) number of thousand algal cells per ml multiplied by 5000. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 200 to (ii) the number of thousand algal cells per ml multiplied by 1500. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 400 to (ii) the number of thousand algal cells per ml multiplied by 800. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being within the range of: (i) the number of thousand algal cells per ml multiplied by 600 to (ii) the number of thousand algal cells per ml multiplied by 700. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least the number of thousand algal cells per ml multiplied by 50. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least the number of thousand algal cells per ml multiplied by 100. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least the number of thousand algal cells per ml multiplied by 200. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least the number of thousand algal cells per ml multiplied by 400. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least the number of thousand algal cells per ml multiplied by 500. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least the number of thousand algal cells per ml multiplied by 600. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least thenumber of thousand algal cells per ml multiplied by 700. In some embodiments, the finalconcentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least the number of thousand algal cells per ml multiplied by 1000. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as being at least the number of thousand algal cells per ml multiplied by 2000. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 50. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 100. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 200. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 500. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 600. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 650. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 700. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 1000. In some embodiments, the final concentration of total nutrient mineral acid(s) after addition of nutrient mineral acid(s) is calculated as the number of thousand algal cells per ml multiplied by 2000. In some embodiments, nutrient mineral acids are added in the first algal culture phase to achieve a pH value in the range of pH6.5-7.5.In a preferred embodiment, the mean photosynthetically active radiation (PAR) and UV light in eachraceway pond does not exceed the light photoinhibition parameter (Ekβ) of the algae. In some embodiments, the algae are green during the first algal culture phase. In some embodiments, the algal growth rate during the first algal culture phase is at least 0.6d-1. In some embodiments, the algal growth rate during the first algal culture phase is at least 0.7d-1. In some embodiments, the algal growth rate during the first algal culture phase is at least 0.8d-1. In some embodiments, the algal growth rate during the first algal culture phase is at least 0.9d-1. In a preferred embodiment, the algal growth rate during the first algal culture phase is at least 0.7d-1. Algal growth rate can be measured by cell density, dry weight biomass, live cell optical density, live cell fluorescence, solvent extracted pigment fluorescence or optical density, carbon content, turbidity or pond tonality via remote sensing imagery.For example, growth rate (µ) may be calculated from the change in biomass from one time point (t0) toa later time point (t1): ^^(^^÷^^) In some embodiments, the algal culture is diluted in each raceway pond in the first algal culturephase, and pond volume for each pond in the second algal culture phase is modelled by the followingequation: ^ ^^^^ wherein V^ is the final post-dilution pond volume, V^ is the pond volume of the preceding pond, and μis the growth rate of the algae in the preceding pond. The volume to dilute the pond can then becalculated as V1-V0. Conversely, if one wishes to target a final pond volume or harvest yield, and knows the growth rate at that pond stage, the equation can be modified where the target volume is divided by the exponent to calculate a starting pond volume. ^ ^^ ^ This then sets the post-dilution volume for the upstream pond. This allows one to model an entire production system (in terms of pond stage volume) from either i), a starting volume, modelling the downstream ponds to a target final volume or ii), a final pond volume, modelling the upstream ponds to a target starting inoculum volume from the laboratory. In some embodiments, the series of connected raceway ponds in the first algal culture phase is a linear series. In some embodiments, the series of connected raceway ponds in the first algal culture phase comprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more open raceway ponds. Second algal culture phase The second algal culture phase comprises culturing algae in one or more induction raceway ponds that are connected to the first series of connected raceway ponds in which algae are cultured in thefirst algal culture phase, wherein the algae are induced to produce HVPs, e.g., by culturing the algaewith limited nutrients, high light exposure, high salinity, low temperature, reducing the dilution rate inthe raceway pond, culturing the algae in shallower water upon transfer into each of the one or more induction raceway ponds than in the final raceway pond of the first series of connected raceway ponds, or culturing the algae in deeper water upon transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. As used herein, the term “induction raceway pond” refers to ponds in which the algae are induced to produce HVPs.In some embodiments, the algae are induced to produce HVPs by culturing the algae with limitednutrients. In some such embodiments, seawater is added to the raceway pond without nutrient supplementation.In some embodiments, the algae are induced to increase production of HVPs by culturing the algae inthe presence of a low concentration of nitrogen. In some embodiments, the concentration of nitrogenis less than 20 µM. In some embodiments, the concentration of nitrogen is less than 19 µM. In someembodiments, the concentration of nitrogen is less than 18 µM. In some embodiments, theconcentration of nitrogen is less than 17 µM. In some embodiments, the concentration of nitrogen isless than 16 µM. In some embodiments, the concentration of nitrogen is less than 15 µM. In someembodiments, the concentration of nitrogen is less than 14 µM. In some embodiments, theconcentration of nitrogen is less than 13 µM. In some embodiments, the concentration of nitrogen isless than 12 µM. In some embodiments, the concentration of nitrogen is less than 11 µM.In a preferred embodiment, the concentration of nitrogen is less than 10 µM. In some embodiments,the concentration of nitrogen is less than 9 µM. In some embodiments, the concentration of nitrogen isless than 8 µM. In some embodiments, the concentration of nitrogen is less than 7 µM. In someembodiments, the concentration of nitrogen is less than 8 µM. In some embodiments, theconcentration of nitrogen is less than 6 µM. In some embodiments, the concentration of nitrogen isless than 5 µM.In some embodiments, the algae are induced to increase production of HVPs by culturing the algae inthe presence of a low concentration of phosphorus. In a preferred embodiment, the concentration ofphosphorus is less than 20 µM. In some embodiments, the concentration of phosphorus is less than19 µM. In some embodiments, the concentration of phosphorus is less than 18 µM. In someembodiments, the concentration of phosphorus is less than 17 µM. In some embodiments, theconcentration of phosphorus is less than 16 µM. In some embodiments, the concentration ofphosphorus is less than 15 µM. In some embodiments, the concentration of phosphorus is less than14 µM. In some embodiments, the concentration of phosphorus is less than 13 µM. In someembodiments, the concentration of phosphorus is less than 12 µM. In some embodiments, theconcentration of phosphorus is less than 11 µM.In some embodiments, the algae are induced to increase production of HVPs by culturing the algae inthe presence of a low concentration of silicon. In a preferred embodiment, the concentration of siliconis less than 20 µM. In some embodiments, the concentration of silicon is less than 19 µM. In someembodiments, the concentration of silicon is less than 18 µM. In some embodiments, theconcentration of silicon is less than 17 µM. In some embodiments, the concentration of silicon is lessthan 16 µM. In some embodiments, the concentration of silicon is less than 15 µM. In someembodiments, the concentration of silicon is less than 14 µM. In some embodiments, theconcentration of silicon is less than 13 µM. In some embodiments, the concentration of silicon is lessthan 12 µM. In some embodiments, the concentration of silicon is less than 11 µM.In some embodiments, the algae are induced to produce HVPs by culturing the algae with high lightexposure. HVPs may be produced by algae as a photoprotective response.In some embodiments, the algae are induced to produce HVPs by culturing the algae by reducing thedilution rate in the raceway pond. Diluting the algae more slowly reduces the light path, and soincreases the relative light exposure of the cells, which can induce HVP production as aphotoprotective response. In some embodiments, the algae are induced to produce HVPs by culturing the algae with low light exposure. This can be facilitated by culturing the algae in deeper water upon transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the algae are induced to produce HVPs by culturing the algae with a high ratioof orange to blue light. This can be facilitated by culturing the algae in deeper water upon transfer into each of the one or more induction raceway ponds, than the water in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two induction raceway ponds that are connected in parallel to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise one induction raceway pond that is connected in parallel to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise two induction raceway ponds that are connected in parallel to the final raceway pond of the first series of connected raceway ponds. In someembodiments, the one or more induction raceway ponds in the second algal culture phase comprisethree induction raceway ponds that are connected in parallel to the final raceway pond of the first series of connected raceway ponds. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise at least two series of induction raceway ponds that are connected in parallel to the finalraceway pond of the first series of connected raceway ponds. In some embodiments, each of the atleast two series of induction raceway ponds comprise at least two induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprise two induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, each of the at least two series of induction raceway ponds comprise three induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise two series of induction raceway ponds that are connected in parallel to the final raceway pond of the first series of connected raceway ponds. In some embodiments, each of the two series of induction raceway ponds comprise at least two induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, each of the two series of induction raceway ponds comprise two induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, each of the two series of induction raceway ponds comprise three induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, the one or more induction raceway ponds in the second algal culture phase comprise three series of induction raceway ponds that are connected in parallel to the final racewaypond of the first series of connected raceway ponds. In some embodiments, each of the three seriesof induction raceway ponds comprise at least two induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, each of the three series of induction raceway ponds comprise two induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, each of the three series of induction raceway ponds comprise three induction raceway ponds that are connected in parallel to the first induction pond in the series. In some embodiments, each of the series of induction raceway ponds, the algae are cultured in water which is at least 25% shallower upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, each of the series of induction raceway ponds, the algae are cultured in water which is at least 20% shallower upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, each of the series of induction raceway ponds, the algae are cultured in water which is at least 15% shallower upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, each of the series of induction raceway ponds, the algae are cultured in water which is at least 10% shallower upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, each of the series of induction raceway ponds, the algae are cultured in water which is at least 5% shallower upon transfer into the final induction pond(s) than upon transfer into the first induction pond. In some embodiments, the culture water depth is at least 40 cm in the induction raceway pond(s). In some embodiments, the culture water depth is at least 35 cm in the induction raceway pond(s). In some embodiments, the culture water depth is at least 30 cm in the induction raceway pond(s). In some embodiments, the culture water depth is at least 25 cm in the induction raceway pond(s). In some embodiments, the culture water depth is at least 20 cm in the induction raceway pond(s). In some embodiments, algae are harvested from one or more induction ponds in the second algalculture phase. In some embodiments, algae are harvested from the final induction ponds of thesecond algal culture phase. In some embodiments, the algae become beige or orange during the second algal culture phase.In some embodiments, the algal growth rate at the end of the second algal culture phase is less than1.0 d-1. In some embodiments, the algal growth rate at the end of the second algal culture phase isless than 0.9 d-1. In some embodiments, the algal growth rate at the end of the second algal culturephase is less than 0.8 d-1. In some embodiments, the algal growth rate at the end of the second algalculture phase is less than 0.7 d-1. In some embodiments, the algal growth rate at the end of thesecond algal culture phase is less than 0.6 d-1. In some embodiments, the algal growth rate at the endof the second algal culture phase is less than 0.5 d-1. In some embodiments, the algal growth rate atthe end of the second algal culture phase is less than 0.4 d-1.Algal growth rate can be measured by cell density, dry weight biomass, live cell optical density, live cell fluorescence, solvent extracted pigment fluorescence or optical density, carbon content, turbidity or pond tonality via remote sensing imagery.For example, growth rate (µ) may be calculated from the change in biomass from one time point (t0) toa later time point (t1): ^^(^^÷^^) In some embodiments, the second algal culture phase in performed for at least eight days. In someembodiments, the second algal culture phase in performed for at least seven days. In someembodiments, the second algal culture phase in performed for at least six days. In someembodiments, the second algal culture phase in performed for at least five days. In some embodiments, the second algal culture phase in performed for at least four days. In some embodiments, the algal culture is diluted in each induction raceway pond in the second algalculture phase, and pond volume for each pond in the second algal culture phase is modelled by thefollowing equation: ^ V ^ ^= V^ ∙ 2^^(^)^wherein V^ is the final post-dilution pond volume, V^ is the pond volume of the preceding pond, and μis the rate of the algae in the preceding pond. The volume to dilute the pond can then becalculated as V1-V0. Conversely, if one wishes to target a final pond volume or harvest yield, and knows the growth rate at that pond stage, the equation can be modified where the target volume is divided by the exponent to calculate a starting pond volume. ^ ^^ ^ This then sets the post-dilution volume for the upstream pond. This allows one to model an entire production system (in terms of pond stage volume) from either i), a starting volume, modelling the downstream ponds to a target final volume or ii), a final pond volume, modelling the upstream ponds to a target starting inoculum volume from the laboratory. In a preferred embodiment, the mean photosynthetically active radiation (PAR) and UV light in each induction raceway pond does not exceed the light photoinhibition parameter (Ekβ) of the algae.In some embodiments, the algae are induced to produce the HVP by culturing the algae with highsalinity. In some embodiments, the algae are cultured at a salinity of at least 40 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 50 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 60 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 70 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 80 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 90 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 100 parts per thousand (‰). In someembodiments, the algae are cultured at a salinity of at least 110 parts per thousand (‰). In someembodiments, the algae are cultured at a salinity of at least 120 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 130 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 140 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 150 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 160 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 170 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 180 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 190 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of at least 200 parts per thousand (‰). In some embodiments, the algae are cultured at a salinity of 40-200 parts per thousand (‰).In some embodiments, the algae are induced to produce the HVP by culturing the algae at lowtemperature. In some embodiments, the algae are cultured at a temperature of less than 20 °C. In some embodiments, the algae are cultured at a temperature of less than 15 °C. In some embodiments, the algae are cultured at a temperature of less than 10 °C.In some embodiments, the algae are induced to produce the HVP by culturing the algae with highsalinity and with high light. In some embodiments, the algae are induced to produce the HVP byculturing the algae at low temperature and with high light. Algal flow management and operational parameters Algae may be cultivated in seawater, hypersaline water, desalination brine, brackish water, wastewater or freshwater. The choice of water for the culture medium will depend on the algae being grown. Algae will be grown in water that replicates their natural growth environment. In preferred embodiments, the algae are cultured in natural seawater. The use of this water source presents advantages over hypersaline evaporative brine or other high-salt sources of water. For example, seawater is abundantly available worldwide and not constrained to specific geographies where there are evaporative basins or salt flats available.Once the seawater has circulated through at least one raceway pond 100 (e.g., the series ofconnected raceway ponds 210), it is cleaned of algae and returned to the warmer ocean surface water, down-current at a distance from the intake to avoid intake of water that has already been used for cultivation of the algae. In one embodiment, algae are first cultivated in at least one stage of covered raceway ponds (210A- 210C). The covered raceway ponds (210A-210C) allow for the control of the algae growth environment. The water used to fill the covered raceway ponds (210A-210C) may be filtered or otherwise treated to remove competing and deleterious organisms before being introduced into the covered raceway ponds. In one embodiment, greenhouses 206 are used to cover the raceway ponds 100 and as a result the algae environment is maintained at a higher than ambient temperature. In this embodiment, the temperature within the covered raceway ponds is between 18 °C and 32 °C, for example between 28°C and 34 °C. This will substantially inactivate organisms acclimated to temperatures of 14°C - 18°Cwhen they are pumped from depth off-shore. Advantageously, covered raceway ponds are less susceptible to contamination, either by bacteria or viruses, or by potentially competing organisms. The relatively controlled environment of the covered raceway pond promotes the algae transitioning intothe exponential growth phase. Passive and / or active ventilation may be used in greenhouse 206 toregulate the temperature. As passive ventilation, greenhouse 206 may have walls that have a mesh netting on the inside and are movable outside which can be shut to retain more heat inside thegreenhouse (e.g., in winter) or moved to allow free air moment (e.g., in summer). For the activeventilation, if a certain temperature threshold is exceeded, vents turn on to remove heat fromgreenhouse 206.As the algal cellular density increases, the algae are successively diluted, preferably by being transferred between stages in the series of covered raceway ponds (to covered raceway ponds ofsuccessively larger volume (e.g., from stage 210A to stage 210B, from stage 210B to 210C). Thissuccessive dilution maintains a relatively low cell density of algae, for example between 100,000 cells / ml and 2,000,000 cells / ml, for example about 350,000 cells / ml. Each transfer of the algae toseed a covered raceway pond in the next stage of the series (i.e., the successive dilution of the algae)can be timed to match the growth rate of the algae, or cellular resource requirements. In oneembodiment, algae reside (i.e., have a residence time) in each stage of covered raceway ponds210A, 210B, 210C for 2 hours to 10 days, for example 2 hours, 3, hours, 5 hours, 12 hours, 24 hours, 36 hours, 2 days, 3, days or 5 days. In one embodiment, the algae reside in each covered raceway pond 210A, 210B, 210C for two days, before being transferred to a raceway pond of larger volume. Inone embodiment, algae remain in a covered raceway pond 210A, 210B, 20C for a length of timesufficient for the algae cellular population to at least double, for example 2 hours, 4 hours, 12 hours, 24 hours, 36 hours or 48 hours. In a specific embodiment, algae remain in a covered raceway pond for 24 hours before being transferred to the next stage in the series. Once the algae enter the exponential growth phase, or when sufficient quantities of algae have been cultivated, the algae are transferred to the first stage of open raceway ponds 210D. In one embodiment, the algae and water are transferred in volumes of 1,000 l to 3,000,000 l, for example 360,000 l to 720,000 l, into the first stage of open raceway ponds 210D. The transfer of a relatively large bolus of algae is intended to seed the open raceway ponds to populate the growth environment with a large excess of several orders of magnitude of the product algae relative to any surviving organisms that were within the source water used in the open raceway pond thereby establishing a robust population.The algae may be diluted (i.e., the dilution rate or dilution volume may be increased) by introducingadditional water into the current stage of ponds (210A-210E), increasing the volume of water contained within that stage. Additional water may be added by opening the sluice gate of the inlet pipe 108 of a raceway pond 100. Alternatively, the algae may be diluted by transferring the algae to the next stage of ponds and mixing the algae with water already present in those ponds. Algae in an open raceway pond 210D, 210E are successively diluted by increasing the volume ornumber of open raceway ponds in each stage of the series (e.g., from stage 210D to 210E). Thisserial dilution maintains the algae at a low enough cell density to sustain exponential growth. In one embodiment, the algae are successively diluted to maintain a cell density of 50,000 cells / ml to100,000 cells / ml, for example 200,000 cells / ml to 250,000 cells / ml. This approach is completelydifferent to current methods of cultivating algae in which the algae are grown to artificially high densities often reaching cell densities of over 1 million cells / ml.In one embodiment, algae reside (i.e., have a residence time) in each stage of open raceway ponds210D, 210E for 2 hours to 5 days, for example 2 hours, 3, hours, 5 hours, 12 hours, 24 hours, 36 hours, 2 days, 3, days or 5 days before being transferred to the next stage of open raceway ponds inthe series (e.g., from stage 210D to 210E). In a specific embodiment, algae remain in a stage of openraceway ponds 210D for 48 hours before being transferred to the next stage of raceway ponds 210E in the series. In one embodiment, algae remain in a stage of an open raceway pond 210D, 210E for alength of time sufficient for the algae cellular population to at least double, i.e., for one round of celldivision to take place. In a specific embodiment, the algae remain in a stage of an open raceway pond 210D, 210E for a length of time sufficient for one, two, three, four or five rounds of cell division to take place. This may be, for example, 2 hours, 4 hours 12 hours, 24 hours, 36 hours, 48 hours, or 72 hours. This successive dilution of algae maintains a low cell density which advantageously maintains the exponential growth phase, thereby increasing productivity. Furthermore, the problems associated with high-density algal culture methods such using traditional raceway ponds and PBRs 204 are avoided. With each successive dilution of the algae, water is added to, and / or is already present in, the covered and open raceway ponds in the next stage 210A-210E in the series. Following the transfer ofthe algae and water from one stage to seed the next stage in the series (e.g., from stage 210A to210B, from 210B to 210C, from 210C to 210D, from 210D to 210E), the volume of fluid within eachraceway pond 100 is equal to the capacity of the raceway pond 100. In one embodiment, the entirevolume of water in a raceway pond 100 is replaced every 2 hours to 8 days, or every 4 hours to 8 days, preferably every 24 to 72 hours. In a preferred embodiment, the volume of water passing through the series of connected covered and open raceway ponds 210 in 24 hours is greater than 20- 250% of the entire volume of the series of covered and open connected raceway ponds 210, e.g., greater than 30% of the entire volume of the series of covered and open connected raceway ponds, for example greater than 100% for both seed and growth ponds. This exchange rate of water is muchhigher than in traditional raceway ponds, where the water replacement rate is usually around 0 – 20%in 24 hours, in order to match the growth rate of the cells and rate of evaporation. This high volume of water exchange has several advantages. In traditional raceway ponds a high cell density of algae is maintained and any contamination can potentially render the entire raceway pondun-harvestable. However, the series of raceway ponds 210 is inherently resilient, as small degrees ofcontamination do not matter since all of the contaminants are inevitably washed out of the series of ponds, and none of the product algae is reintroduced into the series of raceway ponds. Harvesting the algae Harvesting the algae is preferably performed by a method that can be applied to large amounts of water with relatively low energy investment and capital expenditure cost. Accordingly, in some embodiments, the algae are harvested by tangential flow filtration. In some such embodiments, the tangential flow filtration is performed using filters comprising hydrophilic simple weave (irradiated) polyester fabric. Alternatively, in some embodiments, the algae are harvested by filtering with a rotary mesh screen. In some such embodiments, the screen comprises a (pore-sized) mesh and a filter comprising hydrophilic (irradiated) polyester fabric. In some embodiments, algae are harvested from one or more raceway ponds in the second algal culture phase. In some embodiments, algae are harvested from the final induction raceway pond in the second algal culture phase. Suitable rotary mesh screens include (simple weave) polyester screens that have a pore size of 10-200 µM, preferably a pore size of 20-120 µM. In some embodiments, these screens have been irradiated. Advantageously, this makes the screen more hydrophilic, which improves the filtration rate. Suitable rotary mesh screens may comprise a surfactant coating, such as SAATIcare HyphylTM. A further example of a suitable rotary mesh screens is monofilament polyester fabric, such as SUPREX (EXTRIS). In the context of rotary mesh screens, the thinner the fibre strands, the larger the percentage of open area for filtration, which the inventors have found to be advantageous for harvest filtration of algae. Accordingly, in some embodiments, the average fibre strand diameter in a rotary mesh screen less than 50 µM. Accordingly, in some embodiments, the rotary mesh screens have a pore size of 10-200 µM and an average fibre strand diameter of less than 50 µM. Accordingly, in some embodiments, the rotary mesh screens have a pore size of 20-120 µM and an average fibre strand diameter of less than 50 µM. Advantageously, these harvesting methods facilitate the concentration of algal cells without exposureto excess shear or breakage. This facilitates, e.g., the harvest of algal cells that have not formed rigidcysts. Advantageously, these harvesting methods do not require the addition of coagulants or flocculants or other expensive forms of cell concentration such as settling tanks or dissolved air flotation. Advantageously, the algal slurry produced by these harvesting methods may contain the originalcultivation water and may not require refrigeration. The cells are still vital in the slurry and thedewatering does not typically damage the cells, ensuring high product quality.In some embodiments, harvesting the algae produces a 500-1000-fold concentrated algal slurry. This slurry is more concentrated than that which can be obtained by conventional dewatering tools such as continuous flow centrifugation or microtubule cross-flow micro-filtration. In some embodiments, the algal slurry is further dewatered in a centrifuge. The centrifuge is preferably a low-shear centrifuge. Advantageously, this ensures that the cells are not lysed or disrupted while the extracellular seawater is removed. In some embodiments, this results in an algal slurry that contains at least 10% dry weight, wet biomass. In some embodiments, this results in an algal slurry that contains 10-15% dry weight, wet biomass. In some embodiments, after the algal slurry has been further dewatered in a (low-shear) centrifuge, the algal slurry is refrigerated and then subjected to a continuous flow centrifuge. Advantageously, this ensures a consistent flow of biomass is available for extraction.In some embodiments, the algal slurry is acidified (e.g., to pH < 4, such as pH < 3.5) prior to theextraction phase. This is advantageous for microalgae that contain a high level of soluble proteins or soluble starches (like chrysolaminarin) because acidification hydrolyses these large molecules toensure that they do not bind to the HVP (e.g. carotenoid) extracts. Such microalgae includeSkeletonema pseudocostatum, some diazotrophic bacteria, and Chlorella sp..In preferred embodiments, the extraction phase is performed under an inert gas (e.g., a nitrogenblanket). This prevents oxidation of the extracts. Staggered harvesting In another embodiment, algae are harvested from large amounts of water with relatively low energyinvestment and capital expenditure cost by harvesting from the final induction raceway ponds in theharvest phase in a staggered manner. In some embodiments, the penultimate induction raceway pond(s) in the harvest phase are each connected in parallel to at least one further, final raceway ponds. In some embodiments, the penultimate induction raceway pond(s) in the harvest phase are each connected in parallel to at least two further, final raceway ponds. In some embodiments, the penultimate induction raceway pond(s) in the harvest phase are each connected in parallel to at least three further, final raceway ponds. In some embodiments, the penultimate induction raceway pond(s) in the harvest phase are each connected in parallel to at least four further, final raceway ponds. In some embodiments, the final raceway ponds in the harvest phase are connected by pipes which permit the transfer of algal culture between the final raceway ponds.In some embodiments, the harvest phase comprises harvesting algae from one or more of the finalinduction raceway pond(s) in which algae are cultured in the second algal culture phase. In some embodiments, the final induction raceway ponds in the harvest phase are harvested in a staggered manner of at least two harvesting phases, comprising: (i) a first harvesting phase, wherein algae are harvested from one of the final raceway ponds, or simultaneously from two or more of the final raceway ponds, wherein algae are not harvested from at least one of the other final raceway ponds, and (ii) a second harvesting phase, wherein algae are harvested from one of the final raceway ponds or simultaneously from more than one of the final raceway ponds from which algae are not harvested in the first harvesting phase. In some embodiments, the final induction raceway ponds in the harvest phase are harvested in a staggered manner of at least three harvesting phases, comprising: (i) a first harvesting phase, wherein algae are harvested from one of the final raceway ponds, or simultaneously from two or more of the final raceway ponds, wherein algae are not harvested from at least one of the other final raceway ponds, and (ii) a second harvesting phase, wherein algae are harvested from one of the final raceway ponds or simultaneously from more than one of the final raceway ponds from which algae are not harvested in the first harvesting phase. (iii) a third harvesting phase, wherein algae are harvested from one of the final racewayponds or simultaneously from two or more of the final raceway ponds algae were not harvested in thefirst or second harvesting phases.In some embodiments, the second harvesting phase occurs at least one day after first harvesting phase. In some embodiments, the third harvesting phase occurs at least one day after the second harvesting phase. In some embodiments, the final raceway ponds receive further algal culture from the penultimate raceway ponds in the second algal culture phase after harvest. In some embodiments, excess algal culture from one or more raceway ponds in the first algal culture phase is removed by bleeding. In some embodiments, excess algal culture from one or more raceway ponds in the second algal culture phase is removed by bleeding.In some embodiments, the bled algal culture from the first algal culture phase and / or the second algalculture phase is introduced into one or more of the final raceway ponds of the harvest phase. Maintenance of the raceway pondsWhen algae are cultured in a series of connected raceway ponds, such ponds typically producesequential batches of algae as opposed to the steady state continuous harvesting of algae that is traditionally utilised in algal culture. This means that batches of algae can be separated according to need. For example, as the algae pass through the series of connected ponds, trace contamination from the air or other sources may occur, particularly in the open raceway ponds 100. However, the series of connected raceway ponds of the present invention is inherently resilient, because small degrees of contamination do not matter as none of the product algae is reintroduced and all of the contaminants are eventually washed out of the system 200. Furthermore, in one embodiment the dilution of the algae through the repeat addition of seawater also dilutes any contaminants present. Raceway ponds in the series are connected to allow algae and water to flow from one raceway pond to another, but each pond can be isolated when required. Individual raceway ponds in parallel can also be isolated when required. This is particularly useful to allow the ponds to be cleaned to remove sediment or biofilms. Therefore, between batches of algae in different raceway ponds, where algae are transferred every 2, 3, 4, 5, 6, 8, 10, 12, 24, 36 hours, 2 days, 3 days, 5 days apart, amaintenance step can be introduced wherein each raceway pond in the series is sequentially pumpeddry, cleaned, for example with truck-mounted rotating brushes, and flushed with water. Amaintenance step can be performed once a month, and every several maintenance steps an extraday may be introduced to add a day for drying the ponds. Equipment can be cleaned with 0.0001- 0.01% peroxyacetic acid or similar disinfectants such as hypochloric acid before it is seeded with algae from the raceway pond in the preceding stage in the series and topped up with fresh water. In this manner, a running cleaning wave can travel through the entire series of connected covered and open raceway ponds (and the harvesting ponds if desired). This may be scheduled according to the prevalence of oceanic contaminants coming in with the fresh seawater or environmental perturbations such as rainfall or sandstorms. GeneralThe term “comprising” encompasses “including” as well as “consisting” e.g., a composition“comprising” X may consist exclusively of X or may include something additional e.g., X + Y.The term “about” in relation to a numerical value x is optional and means, for example, x+10%. The various steps of the methods may be carried out at the same time or at different times, in thesame geographical location or in different geographical locations, e.g., countries, and by the same ordifferent people or entities.EXAMPLES Example 1Dunaliella salina was grown in a connected series of 15 raceway ponds. The first fourteen pondswere kept under optimal growth conditions for D. salina by successive dilution with nutrient-richseawater in the early mornings and H3PO4 addition in the late afternoons. Overall, the nutrients addedwere 70-110 micromolar nitrate, 6-8 micromolar phosphate and 1 nanomolar iron (III) salt (e.g. ferricchloride). Under these conditions, D. salina was grown on a three-day doubling cycle, such that cellconcentration doubled in three days per unit volume of cultivation water. In these ponds, D. salinawas present as ‘green’ (low beta-carotene content) cells. In the fifteenth pond, the algae were subjected to nutrient limitation. In particular, seawater was added to this pond without additional supplementation of nitrogen or phosphorus. This resulted in the cells converting to ‘orange’ (high beta-carotene content) cells.The algae were then harvested using filter mesh screens that have a pore size of 23 microns. Theseare hydrophilic, polyester woven mesh screens that can be applied to tangential flow filtration or rotarydrum screens. The relatively gently concentration process very rapidly creates a 500 – 1,000-foldconcentration of the cells in the original cultivation water without the need for refrigeration.The cell concentrate (having 2% - 3% dry weight) was further dewatered in a low-shear centrifuge thatensures that the cells are not lysed or disrupted while the extracellular seawater is removed. Thiscentrifuge produced a paste that is 12% - 13% dry weight, wet biomass. This paste was refrigerated,and the biomass was subjected to a continuous flow centrifuge to ensure a consistent flow of biomass was available for extraction. All subsequent steps were performed under a nitrogen blanket to prevent oxidation of the extracts. Extraction of all pigments is performed by suspending approximately 417 g / L of the 12% paste in 100% food grade ethyl acetate, to give a 50 g / L dry weight suspension and agitated for 10 minutes. At this point carotenoids, pigments, some lipids and solvent soluble components have been dissolved in the ethyl acetate. The water phase contains cellular debris and the remainder of the biomass as well as the intracellular salt from Dunaliella salina.The two phases were separated, and the water phase is pumped to solar drying and long-termdisposal in landfill. The ethyl acetate was cleaned of all particulate biomass by means of depth filtration and the solvent was evaporated with vacuum assisted evaporation to create an oleoresin. At this point, 1 volume of water is added to a volume of ethyl acetate extract. When the ethyl acetateevaporates, the beta-carotene forms a precipitate in water. This reduces the quantity of oleoresinwhich adheres to vessel walls to facilitate further processing and to avoid a second resuspension process. The ethyl acetate was condensed, recaptured and recycled. It was passed through a drying column to ensure that it was dry and clean before reuse.The oleoresin was saponified by the addition of a 50% sodium hydroxide solution, to give a finalconcentration of 1 mole per liter, for 1 hour at 60 °C with agitation. The beta-carotene is not watersoluble and forms a slurry that is filtered, and the filter cake is washed with water and subsequentlydried to produce the primary product. The watery alkali filtrate contains lutein which was available for further processing by transferring itinto an organic non-ester solvent, that was re-evaporated, condensed and recycled to form a secondoleoresin rich in lutein. This was similarly dried and collected as a second product. The water phase containing sodium magnesium chlorophyllin was acidified to pH 2-3 by the additionof concentrated hydrochloric acid and is mixed with 10% copper sulfate at 60 °C for 1 hour toprecipitate chlorophyllin salts. The precipitate was collected and dissolved in 95% ethanol and the pHis adjusted to 11 by the addition of 1M sodium hydroxide. The sodium copper chlorophyllin wasfiltered, washed and dried as a third product. The watery filtrate was disposed of as the wet biomassremnants above. Chromatograms for the crude carotenoid extract and the purified carotenoid powder at the end of the process are provided in Figures 4A and 4B, respectively. A chromatogram for a reference carotene product, BASF Betatene®30% OLV, 72% all-trans beta carotene is provided in Figure 4C. Example 2 Below describes an example of the ‘hurry up and wait’ approach, where the pond train is optimised for green (fast growing) algae upstream, and orange (slow growing and stressed) algae downstream.A split pond system having 15 pond stages (Greenhouses 1-6, Clean 1-5, Outdoor 1-5) was tested.There were 22 production ponds in total. Greenhouses 1-6 (G1-G6), Clean 1-5 and Outdoor 1-3(OD1-3) formed a linear series of 14 ponds. The pond train was subsequently non-linear, such thatOD3 is a 1:2 split pond (i.e. x1 OD3 feeds x2 OD4) and each OD4 is a 1:3 split pond (i.e. x1 OD4feeds x3 OD5). Therefore, the pond system contained two OD4 and six OD5 ponds.Preliminary tests showed a D. salina growth rate of 0.7 d-1 in the greenhouse, increasing to 0.78 d-1 inthe outdoor ponds (pre-stressing). These growth rates are representative of a green, vegetative state,with chlorophyll a being the primary photosynthetic pigment. Conversely, a stressed, orange D. salinaculture, high (> 5%) in β-carotene, has a reduced growth rate of ~ 0.26 d-1. Maintaining a reduced Nconcentration (but not limited) with ambient PAR results in an intermediatory state, where D. salina isbeige in colour, growing at 0.40 d-1. For β-carotene production from D. salina, using high light and nitrogen limitation, 5% β-carotene dry weight concentration is achieved after 4 to 6 days of stressing.D. salina was cultured in this split pond system. In this example, all upstream ponds from Outdoor 3(OD3) are run and optimised on a linear 1-day cycle based on the system growth rates for green cultures. Outdoor 3 (OD3) is a split pond on a 1:2 ratio, where one OD3 transfers into two OD4’s. Due to this split, OD4 ponds are shallower post-transfer which increases the PAR at the representative depth. In addition to a shallower post-transfer depth, the daily dilution can be delayed into the photic period.This increases the amount of PAR and light exposure combined with nitrogen limitation, exacerbatesthe degree of cell stressing and rate of β-carotene production. In OD4’s, growth rate is approximately 0.4 d-1. However, the system growth rate for this stage is 0.36 d-1(the minimum observed growth rate). Due to half the transfer volume going into each OD4 (due to the 1:2 split) and growth rates at this stage, this pond stage is able to run on a 2-day growth cycle before achieving a target 1 m pond depth. In other words, OD3 transfers into both OD4’s everyday (1-day cycle), whilst OD4’s transferinto OD5’s every two days. This pond stage specific increase in daily cycle time ensures that thetarget OD4 final pond volumes (pre-transfer) are achieved. This ensures OD5 ponds are receivingtarget transfer volume, and do not void this system’s minimum pond depth limit for mixing (20 cm).Having 1-day cycle ponds transfer into 2-day cycle ponds creates a potential bottleneck in the system. This is factored into the design when optimising OD4 pond sizings. This consists of making OD4’sreceive and dilute culture from OD3 on day 1, then receiving an additional transfer from OD3 on day 2(integrated with the existing volume) before diluting the total volume based on growth rate. At the end of OD4 cultivation, the culture has been stressed for 2 days and is beginning to increase in β-carotene concentration. OD4’s then transfer into the final pond stage (OD5’s) for the remaining period of stressing. At this stage, growth rate decreases yet further to 0.26 d-1. To optimise and achieve maximum pond volumes (i.e.12,000 m3per OD5 pond) pre-harvest, this final stage is operated on a 4-day cycle. OD4 ponds are split ponds on a 1:3 ratio (two OD4’s feed six OD5’s). This maintains the aforementioned advantage of intentionally operating shallower ponds (on day 1 and 2) in this final stage, which increases sample depth PAR, which in turn increases the degree of algal stressing and β-carotene production. It also means that OD5 ponds are optimised to receive OD4 transfers on day 1 and day 3. In other words, for every OD5 cycle (4 days), OD4 performs two cycles,and OD3 (and upstream) perform four cycles. The algae are harvested from the OD5 ponds.In this example system, the ‘hurry up and wait’ approach maximised cycle harvested biomass as1584 kg, which constitutes 396 kg d-1, with cellular β-carotene content of 5%. This yields 19.8 kgβ-carotene d-1and 2.123 kg β-carotene ha d-1. This approach provided greatly improved land use- normalised yield (kg β-carotene ha d-1) compared to a linear system cultivating green or beige algae. As a comparison, with an equivalent site area to the hurry up and wait design, a linear 1-day pondcycle growing green (fast growth) D. salina at 0.78 d-1 requires 15 pond stages (G1-G5, Clean 1-5,OD1-5) with 60 production ponds in total. The details for this pond system are provided inTables 6-10. This approach delivers 264 kg d-1 of biomass from 48,000 m3 d-1. β-carotene content ingreen biomass is significantly lower (0.1 to 0.5%). Even assuming the upper estimate, yields reduce to 1.320 kg β-carotene d-1and 0.149 kg β-carotene ha d-1; an order of magnitude lower than the hurry up and wait approach. Alternatively, again using an equivalent site area to the hurry up and wait design and cultivatingbeige-like (moderately stressed) D. salina cultures growing at 0.40 d-1 requires 29 pond stages (G1-G13, Clean 1-10, OD1-6) with 58 production ponds in total. This approach delivers a similar dailyharvested biomass (354 kg d-1) from 16,101 m3d-1, but uses an additional more than twice the ponds than the ‘hurry up and wait’ approach. The β-carotene content in beige-like biomass, although higher than green biomass, is still significantly lower (1.8%) than fully stressed cells, making constant beige cultivation yield 6.376 kg β-carotene d-1and 0.657 kg β-carotene ha d-1.For D. salina cultivation of β-carotene, a ‘hurry up and wait’ approach utilising pond splitting gives 14times and 3.2 times increase in land use-normalised yield (kg β-carotene ha d-1) compared to a linearsystem cultivating green or beige algae, respectively.The dynamic system growth rates are far more productive in terms of throughput and yield than tryingto maintain a physiologically semi-stressed culture with a constant growth rate throughout the pondtrain.A split pond system is especially well-suited to deploying the ‘hurry up and wait’ approach. While thisapproach can be deployed in an entirely linear system, the stressing period and the transition timefrom green to orange cells would need to be extended for the system to be more productive.The use of a ‘clustering’ approach (staggered harvesting) in combination with the ‘hurry up and wait’approach improved land-normalised daily beta-carotene production (kg ha d-1) by ~37% relative todeploying the same 'hurry up and wait' approach without clustering. Example 3 The use of a ‘hurry up and wait’ approach is shown for other HVP types, namely mycosporin-like amino acids (MAAs), phycobilins, lipids, carbohydrates and proteins in Tables 1-28. These results show that these HVPs can be produced in a highly efficient manner using the ‘hurry up and wait’ approach. Furthermore, the use of a ‘clustering’ approach (staggered harvesting) in combination with the ‘hurry up and wait’ approach improved land-normalised daily HVP production(kg ha d-1). Example 4 On a linear system, where growth rate is maximised and sustained throughout the entire production cycle, split ponds has no increase to harvest yields and actually reduces yield normalised to land use. For example, at a growth rate of 1.1 d-1, harvesting 12,000 m3per day, a linear pond train yields 384 kg biomass on a 1-day cycle and 192 kg biomass on a 2-day cycle). A split pond approach yields thesame metrics but requires 68 ponds in comparison to the 11 needed for a linear system.That said, split ponds on a 1:2 factor (i.e. one pond inoculating two ponds) has significant benefits forcarotenoid (e.g. β-carotene) production. The reason being, as illustrated in Figure 10,post-transfer / pre-dilution volumes are reduced by a factor of 2, which increases PAR within the water column. This significantly increases the quantity of PAR at depth, as well as the relative fraction of shortwave and UV light in the spectral quality of light. Measuring and / or modelling the incident PAR on the pond surface enables one to calculate the fraction of light being transmitted into the boundary layer (downwelling PAR) versus reflected back into the atmosphere (Upwelling PAR). Having established the PAR at zero-depth (E0), one can thenapply species-specific light attenuation (kdSPAR) factors (which are modelled or measured directly bychanges in optical density with increasing pathlength) to calculate the PAR at any depth (Ez). Lightattenuation is non-linear with depth, so half the pond depth does not equate to a mean PAR of thewater column. To assess light availability with depth on algal productivity, one calculates the“representative depth” or “sample depth”, which is the depth at which PAR is the mean of the watercolumn (see Figure 10).With the assumption that all ponds are well mixed, and all algae are evenly distributed within thewater column, in-pond PAR at the sample depth can be compared against a measured and / or modelled time-dependent species light photoinhibition parameter (Ekβ). This determines a setpoint for the system design, in terms of determining the degree of shallowing of the final few pond stages (i.e.split pond on a 1:2, 1:3 or 1:4 ratio) to maximise algal stressing and carotenoid (e.g. β-carotene)production. Example 5Dunaliella salina was grown and harvested according to the method set out in Example 1. A 2gsample of the harvested biomass was taken and “wet” extraction of trans-beta carotene and lutein was carried out according to the method set out in Example 1. A further 2g sample of the harvested biomass and “dry” extraction of beta carotene and lutein from 2g of the same initial biomass was also carried out according to the method of Example 1, with the addition of a drying step (70 °C overnight) after the algae were harvested. Samples were analysed by chromatography according to Example 1 to obtain an absorbance pergram value for trans beta-carotene and lutein, which are set out in the table below.Biomass type Biomass (g) Solvent Product Absorbance units Trans beta-carotene 9,656,406 As shown above, wet extraction resulted in 1.5x and 1.9x the amount of trans beta-carotene andlutein as that obtained via dry extraction. Indeed, given that 2g of wet biomass would contain asignificant amount of water, the improvement relative to 2g of dry biomass is especially strong. Accordingly, omitting a drying step from the extraction process is advantageous in terms of extraction efficiency. REFERENCES Bhumibhamon, O., Sittiphuprasert, U., Boontaveeyuwat, N. and Praiboon, J., 2003. The optimum useof salinity, nitrate and pond depth for β-carotene production of Dunaliella salina. Agriculture andNatural Resources, 37(1), pp.84-89.Black, H.S., Boehm, F., Edge, R. and Truscott, T.G., 2020. The benefits and risks of certain dietary carotenoids that exhibit both anti-and pro-oxidative mechanisms—A comprehensivereview. Antioxidants, 9(3), p.264.Corrêa, P.S., Morais Júnior, W.G., Martins, A.A., Caetano, N.S. and Mata, T.M., 2020. Microalgaebiomolecules: Extraction, separation and purification methods. Processes, 9(1), p.10.Ernst, H., Henrich, K. , Keller, A., 2003., Method for producing carotenoids, US20060106257A1 Furukawa, T., Watanaba, M. and Shihira-Ishikawa, I. Green and blue-light-mediated chloroplastmigration in the centric diatom Pleurosira laevis Protoplasma, 203;214-220 (1998).Ghazi, A., 1999. Extraction of β-carotene from orange peels. Food / Nahrung, 43(4), pp.274-277.Grune, T., Lietz, G., Palou, A., Ross, A.C., Stahl, W., Tang, G., Thurnham, D., Yin, S.A. and Biesalski,H.K., 2010. β-Carotene is an important vitamin A source for humans. The Journal ofnutrition, 140(12), pp.2268S-2285S.Gupta, A.K., Seth, K., Maheshwari, K., Baroliya, P.K., Meena, M., Kumar, A. and Vinayak, V., 2021.Biosynthesis and extraction of high-value carotenoid from algae. Frontiers in Bioscience-Landmark, 26(6), pp.171-190.Johnson, E.J., Qin, J., Krinsky, N.I. and Russell, R.M., 1997. β-Carotene isomers in human serum,breast milk and buccal mucosa cells after continuous oral doses of all-trans and 9-cis β-carotene. TheJournal of nutrition, 127(10), pp.1993-1999.Kraml, M. and Herrmann, H. Red–blue interaction in Mesotaenium chloroplast movement—blueseems to stabilize the transient memory of the phytochrome signal. Photochem. Photobiol., 53:255– 259 (1991) Kusmayadi, A., Suyono E. A., Nagarajan, D., Chang, J.-S. and Yen, H.W., Application of computational fluid dynamics (CFD) on the raceway design for the cultivation of microalgae: a review, 2020, Journal of Industrial Microbiology and Biotechnology, 47(4-5):373–382. Mendes, R.L., Fernandes, H.L., Coelho, J., Reis, E.C., Cabral, J.M., Novais, J.M. and Palavra, A.F.,1995. Supercritical CO2 extraction of carotenoids and other lipids from Chlorella vulgaris. Foodchemistry, 53(1), pp.99-103.Takaichi, S. Carotenoids in Algae: Distributions, Biosyntheses and Functions, 2011, Marine Drugs 9(6):1101-1118. Wolf, L., Cummings, T., Müller, K., Reppke, M., Volkmar, M. and Weuster-Botz, D., 2021. Productionof β-carotene with Dunaliella salina CCAP19 / 18 at physically simulated outdoorconditions. Engineering in life sciences, 21(3-4), pp.115-125

[0002] TABLES Mycosporin-like amino acids (MAAs) Table 1 – Clustered 1-day cycle pond specification (MAAs)

[0003]

[0004]

[0005] Table 2 – System summary – cluster ponds only (MAAs)

[0006] Table 3 – Overall system summary - clustered (MAAs)

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016] Table 4 – Summary – clustered (MAAs)

[0017] Table 5 – Clusterless 1-day cycle pond specification (MAAs)5

[0018]

[0019]

[0020] Table 6 – Overall system summary – clusterless (MAAs)

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] Table 7 – Summary – clusterless (MAAs)

[0027] Phycobilins Table 8 – Clustered 1-day cycle pond specification (phycobilins)

[0028]

[0029] Table 9 – System summary – cluster ponds only (phycobilins)

[0030] Table 10 – Overall system summary – clustered (phycobilins)

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] Table 11 – Summary – clustered (phycobilins)

[0039] Table 12 – Clusterless 1-day cycle pond specification (phycobilins)

[0040]

[0041] Table 13 – Overall system summary – clusterless (phycobilins)

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049] Table 14 – Summary – clustered (phycobilins)

[0050] Lipids Table 15 – Clustered 1-day cycle pond specification (lipids)

[0051]

[0052] Table 16 – System summary – cluster ponds only (lipids) Table 17 – Overall system summary – clustered (lipids)

[0053] 5

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] Table 18 – Summary – clustered (lipids)

[0062] Table 19 – Clusterless 1-day cycle pond specification (lipids)

[0063]

[0064] Table 20 – Overall system summary (lipids)

[0065]

[0066]

[0067]

[0068]

[0069]

[0070] 5

[0071]

[0072] Table 21 – Summary – clusterless (lipids)

[0073] Carbohydrates / proteins Table 22 – Clustered 1-day cycle pond specification (carbohydrates / proteins)

[0074]

[0075] Table 23 – System summary – cluster ponds only (carbohydrates / proteins)

[0076] Table 24 – Overall system summary – clustered (carbohydrates / proteins)

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084] Table 25 – Summary – clustered (proteins / carbohydrates)

[0085] Table 26 – Clustered 1-day cycle pond specification (carbohydrates / proteins)

[0086]

[0087] Table 27 – Overall system summary – clustered (carbohydrates / proteins)

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095] Table 28 – Summary – clusterless (proteins / carbohydrates)

Claims

CLAIMS1. A method for producing a high value product (HVP), wherein the method comprises:(a) a first algal culture phase,wherein the first algal culture phase comprises culturing marine HVP-producingmicroalgae in a first series of connected raceway ponds, arranged in stages,and wherein the algae are maintained in the exponential growth phase by successive dilution with seawater and nutrient addition;(b) a second algal culture phase, wherein the second algal culture phase comprises culturing the algae in one or moreinduction raceway ponds that are connected to the first series of connected raceway ponds inwhich algae are cultured in step (a), wherein the algae are cultured under stress conditions that induce the algae toincrease HVP production;(c) a harvest phase, wherein the harvest phase comprises harvesting algae from one or more of the induction raceway pond(s) in which algae are cultured in step (b); and(d) an extraction phase, wherein the extraction phase comprises extracting the HVP from the algae harvested in step (c).

2. The method of claim 1, wherein the HVP comprises carbohydrates (e.g. polysaccharides), lipids, proteins, pigments and / or bioavailable minerals.

3. The method of claim 2, wherein the HVP is a polysaccharide, lipid, protein, pigment or bioavailable mineral.

4. The method of any one of claims 1-3, wherein the stress conditions comprise nitrogen, phosphorus and / or silicon limitation, optionally wherein:(i) the concentration of nitrogen in step (b) is less than 10 μM,(ii) the concentration of phosphorus in step (b) is less than 20 μM, and / or(iii) the concentration of silicon in step (b) is less than 20 μM.

5. The method of claim 4, wherein the stress conditions comprise nitrogen limitation, optionally wherein the concentration of nitrogen in step (b) is less than 10 μM.

6. The method of any one of claims 1-5, wherein the stress conditions comprise high light.

7. The method of claim 6, wherein, upon transfer into each of the one or more induction racewayponds, the algae are cultured in water that is at least 10% shallower than the water in which the algaeare cultured in the final raceway pond of the first series of connected raceway ponds.

8. The method of claim 6 or claim 7, wherein the algae are cultured in shallower water, for at least thefirst day following transfer into each of the one or more induction raceway ponds, than the water inwhich the algae are cultured in the final raceway pond of the first series of connected raceway ponds.

9. The method of claim 6 or claim 7, wherein the mean UV and photosynthetically active radiation(PAR) does not exceed the light photoinhibition parameter (Ekβ) of the algae.

10. The method of any one of claims 6-9, wherein the culture water depth is at least 20 cm in the induction raceway pond(s).

11. The method of any one of claims 6-10, wherein the one or more induction raceway ponds in step(b) comprise at least two induction raceway ponds that are connected, in parallel, to the final raceway pond of the first series of connected raceway ponds.

12. The method of claim 11, wherein the one or more induction raceway ponds in step (b) comprise atleast two series of induction raceway ponds that are connected, in parallel, to the final raceway pondof the first series of connected raceway ponds.

13. The method of claim 12, wherein each of the at least two series of induction raceway pondscomprises:(i) at least two induction raceway ponds that are connected, in parallel, to the first induction pond inthe series, or (ii) at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series.

14. The method of claim 12 or claim 13, wherein in each of the series of induction raceway ponds, thealgae are cultured in (10%) shallower water upon transfer into the final induction pond(s) than upontransfer into the first induction pond.

15. The method of any one of claims 6-14, wherein the algae are green during the first algal culture phase, and wherein the algae become beige or orange during the second algal culture phase.

16. The method of any one of claims 6-15, wherein the HVP comprises (UVB and UVC-resistant)phycocolloids and / or mycosporin-like amino acids (MAAs).

17. The method of any one of claims 1-5, wherein the stress conditions comprise low light or a highratio of orange to blue light.

18. The method of claim 17, wherein the stress conditions comprise a high ratio of orange to blue light.

19. The method of claim 18, wherein the HVP comprises phycobilin proteins, such as phycoerythrin,phycocyanin or allophycocyanin.

20. The method of claim 19, wherein the HVP-producing microalgae are cyanobacteria or diatom-diazotroph assemblages (DDAs).

21. The method of any one of claims 17-20, wherein upon transfer into each of the one or moreinduction raceway ponds, the algae are cultured in water that is at least 10% deeper than the water inwhich the algae are cultured in the final raceway pond of the first series of connected raceway ponds.

22. The method of any one of claims 17-21, wherein the algae are cultured in deeper water, for atleast the first day following transfer into each of the one or more induction raceway ponds, than thewater in which the algae are cultured in the final raceway pond of the first series of connected raceway ponds.

23. The method of claim 1, wherein:(i) the HVP comprises lipids (e.g. fatty acids), and wherein the stress conditions comprise nitrogenlimitation (e.g. the concentration of nitrogen in step (b) is less than 10 μM), or(ii) the HVP comprises proteins (e.g Rubisco) and / or carbohydrates, and wherein the stressconditions comprise silicon limitation (e.g. the concentration of silicon in step (b) is less than 20 μM).

24. The method of any one of claims 1-23, wherein the penultimate induction raceway pond(s) in step (c) are each connected in parallel to at least two further, final raceway ponds.

25. The method of any one of claims 1-23, wherein the penultimate induction raceway pond(s) in step(c) are each connected in parallel to at least three further, final raceway ponds.

26. The method of claim 24 or claim 25, wherein the final raceway ponds in step (c) are connected bypipes which permit the transfer of algal culture between the final raceway ponds.

27. The method of any one of claims 24-26, wherein the harvest phase comprises harvesting algaefrom one or more of the final induction raceway pond(s) in which algae are cultured in step (b).

28. The method of claim 27, wherein the final induction raceway ponds are harvested in a staggered manner of at least two harvesting phases, comprising: (i) a first harvesting phase, wherein algae are harvested from one of the final raceway ponds, or simultaneously from two or more of the final raceway ponds, wherein algae are not harvested from at least one of the other final raceway ponds, and (ii) a second harvesting phase, wherein algae are harvested from one of the final raceway ponds or simultaneously from more than one of the final raceway ponds from which algae are not harvested in the first harvesting phase.

29. The method of claim 28, wherein the second harvesting phase occurs at least one day after first harvesting phase.

30. The method of claim 28 or claim 29, wherein the method further comprises the following step:(iii) a third harvesting phase, wherein algae are harvested from one of the final racewayponds or simultaneously from two or more of the final raceway ponds algae were not harvested in thefirst or second harvesting phases.

31. The method of claim 30, wherein the third harvesting phase occurs at least one day after thesecond harvesting phase.

32. The method of any one of claims 27-31, wherein the final raceway ponds receive further algal culture from the penultimate raceway ponds in step (b) after harvest.

33. The method of any one of claims 1-32, wherein excess algal culture from one or more raceway ponds in steps (a) or (b) is removed by bleeding, optionally wherein the bled algal culture is introduced into one or more of the final raceway ponds of step (b).

34. The method of any preceding claim, wherein the marine HVP-producing microalgae areChlorophyta, Chlorarachniophyta, Haptophyta, Dinophyta, Euglenophyta, Heterokontophyta(e.g. Chrysophyceae, Raphidophyceae, Bacillariophyceae, Phaeophyceae, Xanthophyceae orEustigmatophyceae), Cryptophyta, unicellular Rhodophyta, Glaucophyta or Cyanophyta, optionally wherein the marine HVP-producing microalgae are:(a) Rhopalodiaceae sp., Hemiaulus sp., Climacodium sp., Skeletonema sp., Chaetocerossp., Thalassiosira sp., Coscinodiscus sp., Navicula sp., Synedra sp. or Nitzschia sp., or(ii) Dunaliella sp.

35. The method of claim 34, wherein the marine HVP-producing microalgae are Dunaliella sp. (e.g. D.salina).

36. The method of any one of claims 1-35, wherein the algal culture is diluted in each raceway pondin the first algal culture phase, and wherein pond volume for each pond in the first algal culture phaseis modelled by the following equation: ^ V ^ ^= V^ ∙ 2^^(^)^wherein V^ is the final post-dilution pond volume, V^ is the pond volume of the preceding pond, and μis the growth rate of the algae in the preceding pond.

37. The method of any one of claims 1-36, wherein the algal culture is diluted in each inductionraceway pond in the second algal culture phase, and wherein pond volume for each pond in thesecond algal culture phase is modelled by the following equation:^ V ^ ^= V ∙ 2 ^^(^)^ ^wherein V^ is the final post-dilution pond volume, V^ is the pond volume of the preceding pond, and μis the growth rate of the algae in the preceding pond.

38. The method of any one of claims 1-37, wherein the algal growth rate during step (a) is at least0.7d-1 (e.g. 0.7-1.0 d-1) and / or wherein the algal growth rate at the end of step (b) is less than 0.6 d-1(e.g. 0.5 d-1).

39. The method of any one of claims 1-38, wherein the series of connected raceway ponds in step (a) is a linear series.

40. The method of any one of claims 1-39, wherein the series of connected raceway ponds in step (a) comprises a first stage comprising one or more covered raceway ponds and a second stage comprising one or more open raceway ponds.

41. The method of any one of claims 1-40, wherein the nutrient addition in step (a) comprises adding one or more nutrient mineral acids, optionally wherein the one or more nutrient mineral acids are selected from nitric acid, phosphoric acid and silicic acid.

42. The method of any one of claims 1-41, wherein the concentration of nitrogen in step (b) is lessthan 10 μM.

43. The method of any one of claims 1-42, wherein the second algal culture phase is performed for atleast four days (e.g.4-10 days).

44. The method of any one of claims 1-43, wherein the harvesting algae in step (c) is from the final induction pond(s).

45. A raceway pond system, comprising: (a) a linear series of connected raceway ponds comprising a first stage comprising one or more covered raceway ponds and a second stage comprising one or more open raceway ponds; and (b) at least two series of induction raceway ponds that are connected, in parallel, to the final raceway pond of the linear series of connected raceway ponds, wherein each of the at least two series of induction raceway ponds comprises at least two induction raceway ponds that are connected, in parallel, to the first induction pond in the series.

46. The raceway pond system of claim 45, wherein each of the at least two series of induction raceway ponds comprises at least three induction raceway ponds that are connected, in parallel, to the first induction pond in the series.

47. The raceway pond system of claim 45 or claim 46, wherein the culture medium is seawater.

48. The raceway pond system of any one of claims 45-47 for use in culturing marine microalgae.

Images