Movable land-based seaweed cultivation device

Abstract

To provide a ground device that cultures seaweed.SOLUTION: A system includes a device that provides a plurality of containers for holding seaweed selected for culture. These containers are disposed in a vertical structure, and each container is vertically shifted from adjacent up and down containers. This system has means to circulate seawater rich in nutrients through each container.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mobile land-based aquaculture device. [Background technology]

[0002] Obesity has reached epidemic proportions around the world, with 2.8 million deaths annually due to being overweight or obese in 2016, according to the World Health Organization.

[0003] In the UK alone, 40,000 people under the age of 75 die from cardiovascular disease (CVD) each year, but it is said that this number could be reduced by 30,000 deaths by appropriately limiting the consumption of saturated fat, industrial trans fat, and salt, while increasing the consumption of vegetables and fruit. Despite extensive food and nutrition research, it has been proven that a diet rich in phytonutrients and antioxidants (increased vegetable and fruit intake), along with reduced consumption of meat, saturated fat, salt, sugar, and full-fat dairy products, reduces the risk of cardiovascular disease, some cancers, diabetes, and several other chronic diseases.

[0004] One effort aimed at preventing preventable chronic non-communicable diseases linked to obesity is to promote a healthy and delicious Japanese diet rich in fresh vegetables, legumes and seaweed such as nori.

[0005] In Japan, a large population-based study examined the association between diet quality and mortality in 43,676 subjects who participated in a 10-year follow-up study, and the results showed that participants who adhered to dietary guidelines centered on a Japanese diet had a lower risk of death from cardiovascular disease, especially cerebrovascular disease.

[0006] Nori is recognized by many people around the world because sushi is eaten all over the world. In Japan, about 50 kinds of seaweed are used for food, of which 48% are red algae. This is because the marine environment around Japan is suitable for their growth. Most species live in the intertidal zone, making them easy to harvest and accessible to everyone.

[0007] Nori was harvested in the wild until around 1687 AD, but since then, cultivation has become established.

[0008] Asakusa-nori (Pyropia tenera) is the oldest and tastiest seaweed in Japan. Until the late 1960s, it was the main species of seaweed for wild-collection farms, but is now included in the Regional Red List, which reports the threat status of species in specific countries and regions. This species is highly sensitive to environmental changes, such as the reclamation of shallow tidal flats. Since the 1960s, Susabinori (Neopyropia yezoensis) has gradually become the main cultured species due to its high resistance to environmental changes, pollution, and disease.

[0009] The present invention aims to provide a sustainable land-based seaweed cultivation device that can harvest edible seaweed and be used for the production and stable supply of, for example, nori seaweed, and is suitable for use in agricultural land locations.

[0010] Porphyra dioica is one of two seaweed species considered during the development of the present invention. This seaweed species is commonly found in the UK, the Faroe Islands, Helgoland, France and Portugal. The species was harvested from the west coast of Kintyre in 2013 and 2014. The land-based farm is adjacent to the North Atlantic coastline where many species of seaweed grow, including Porphyra dioica.

[0011] Porphyra purpurea is another species that was considered during the development of the present invention. This species is widespread and occurs in the British Isles, Iceland, Norway, Portugal and the Baltic States.

[0012] The Porphyra genus is susceptible to several diseases that can severely reduce the yield and quality of nori sheets.

[0013] Red rot disease is caused by infection with a bacterium called Phytium porphyrae. It occurs annually in Japan as well as Korea and is characterized by rust-colored round spots on the thallus surface. It occurs in the waters of Japan throughout the year in January, when seawater temperatures are abnormally high, salinity is low, and pH is low. This bacterium has the ability to adapt to a wide range of salinity. Thallus of mature Porphyra species that have not been dried offshore during the Nori cultivation period are at high risk of infection, so Nori cultivation ropes should be dried in air for 2-4 hours every day to suppress the growth of this bacterium. Early harvesting offshore and acid treatment are also known to be efficient. Cell fusion has been attempted to select strains resistant to the disease and has been reported to be efficient.

[0014] Pot rot is caused by infection with the phycomycete Olpidiopsis porphyrae sp.nov., which occurs in the cells of the thallus of Porphyra species, causing growth inhibition and quality loss. It infects each cell and is only noticeable at the final stage. The conchocelis living in the shell can also be infected. It can occur throughout the cultivation period of Porphyra species. Once it occurs, the yield can be devastating, since in contrast to red rot, it can infect Porphyra species at the young leaf stage. It is thought to be transmitted by secondary infection, so it is important to screen regularly and detect it as early as possible.

[0015] Green spot disease appears as rust-red spots that quickly turn into small green spots. The spots grow into large circles on the inner parts of the thallus. Similar symptoms have been reported due to infection with three different bacteria: Micrococcus sp., Pseudomonas sp., and Vibrio sp. However, environmental factors may also be involved.

[0016] Chirimen disease begins with the formation of small wrinkles on the young leaves or thallus of the Porphyra plant, which then become very finely wrinkled, similar to cancerous tumors. Infected thallus does not die, but growth is stunted and the quality of the Nori sheets is reduced. The cause is unknown. It occurs near the mouths of rivers and shallow bays where water movement is restricted.

[0017] White rot is caused by infection with the bacterium Aquimarina sp. The tips of mature leaves turn red or white and the tissue disintegrates. As a result, the size of the thallus decreases. It has been reported that thallus growing vertically downward in seawater is more susceptible to infection. The causes are thought to be related to drying time, tidal changes, and the amount of light received. Acid treatment and drying offshore are effective preventative methods.

[0018] Ichsatosis affects the conchocelis that grows on the shells of the commercially important Porphyra yezoensis. This fungus, a member of the genus Phoma, causes the disease at the conchocelis stage, which is the most destructive and frequent stage. The fungus has a high degree of environmental adaptability and resistance.

[0019] The main objective of the invention is to make offshore farms less vulnerable to the vagaries of climate change, reduce unsustainable economic and environmental pressures, and reduce the time and physical labor required.

[0020] In many countries, including Japan, profit-maximizing agricultural practices have led to environmental stress and pollution of soil and water resources, including oceans, through the spraying of chemicals and fertilizers. Countries are now trying to shift to sustainable agriculture by incorporating innovative technologies into agricultural practices.

[0021] The present invention provides a weather-resistant, cost-effective and productive seaweed farming system that utilizes sterilizable and recyclable plastic containers.

[0022] In seaweed farming, it is difficult to simultaneously reduce production costs and improve environmental and ecological sustainability in the production system. Since 1993, Nori farmers have used acid treatment of seaweed offshore during the cultivation of Amanori species. The aim is to increase disease resistance, remove epiphytes, provide nutrients, and preserve the economically valuable unique color. Acid treatment of seaweed is generally carried out every year from the end of December to February at offshore farms by pouring the acid treatment on board a vessel and pulling the Nori cultivation net directly into it. The chemical composition of the acid treatment of seaweed varies from region to region. Before 2002, it consisted of 18% DL-malic acid, 15% ammonium sulfate, 14% sodium dihydrogen phosphate, 1% amino acids, and 0.6% pigments. In the Ariake Sea, the largest bay in the Kyushu region of the Japanese archipelago, approximately 2,900 tons of used residual liquid was discharged directly into the sea at aquaculture sites every year between 1971 and 2001, although the acidity of the residual liquid was reduced before discharge. In 2010, three Japanese professors emeritus who are leading experts in the field of oceanography issued an official joint statement to the Japanese government, reporting that the acid treatment of Nori contains citric acid, malic acid, and lactic acid, the use of which is prohibited under international maritime law. It was also pointed out that the acid treatment of Nori contains nutrients such as phosphates, nitrates, ammonia, and sulfates, which may induce eutrophication with serious consequences for some benthic species. In the Ariake Sea, it is believed that the acid treatment of Nori has reduced salinity and pH and increased sulfides in the tidal flats.

[0023] The aim of this invention is to provide a Nori farm that employs only sustainable and environmentally friendly cultivation methods based on the extensive experience of Japanese Nori cultivation. The system is innovative in that it does not use acid treatments for Nori. [Brief description of the drawings]

[0024] [Figure 1] Schematic diagram of the system's aquaculture equipment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] An example system will now be described with reference to FIG. According to the first type, a land-based seaweed cultivation device is provided in which a plurality of containers are arranged in a vertical structure so that the containers do not overlap each other, each container is used to grow seaweed, and seawater containing nutrients that promote growth flows through each container and circulates throughout the system.

[0026] Preferably, the system further includes an electric pump that pumps the nutrient-added seawater that reaches the bottommost vessel back up to the topmost vessel and again from top to bottom.

[0027] Preferably, the system further includes a filtration device and / or a disinfection device for filtering and / or disinfecting the seawater circulated from the electric pump to the uppermost vessel.

[0028] Preferably, the system further comprises circulating nutrient-enriched seawater through the closed system.

[0029] Preferably, the system further comprises blowing air into the circulating seawater to inject air bubbles.

[0030] Preferably, the architectural structure of the system includes a number of container structures.

[0031] Preferably, the building structure of the system is equipped with temperature and lighting control systems.

[0032] Preferably, the seaweed species for cultivation is selected from the genus Porphyra.

[0033] Preferably, the seaweed species for cultivation is selected from the immature thallus of Porphyra purpurea. Alternatively, the seaweed species for cultivation is selected from the immature thallus of Porphyra dioica.

[0034] The present invention provides a mobile land-based seaweed farming device designed for the cultivation of Porphyra and Ulva, which allows seaweed to be cultivated throughout the year. The use of greenhouses along the coastline as cultivation space promotes growth, maintains productivity, and reduces labor hours, especially during the summer when nutrients are scarce.

[0035] Offshore seaweed farming in conjunction with mobile land-based seaweed farming units could include not only Porphyra and Ulva species but also other seaweed species such as Laminaria digitata, Saccharina latissima and Himanthalia elongata.

[0036] The development of this system is based on extensive research and studies by the applicant, focusing on the vegetative growth rates of two Porphyra species of particular interest in relation to seaweed farming systems and on developing strategies to ensure a constant supply of conchospores throughout the year.

[0037] The first series of experiments, detailed below, was designed to test the feasibility of the mobile land-based seaweed farming apparatus shown in Figure 1 as part of a land-based aquaculture system.

[0038] A second series of experiments was also conducted to find a suitable method for the year-round management of conservation shell conchoidal cultures of Porphyra dioica and Porphyra purpurea.

[0039] The system includes a number of stacked bins 2 connected at each level to a central post 4 upstanding from a base 6 which provides stability to the apparatus. The bins 2 each form a relatively shallow container having a bottom surrounded by upright walls in which the seaweed is held. The bins 2 are approximately semicircular and vertically offset from one another to provide a downward spiral path for nutrient rich seawater to flow through all of the bins 2.

[0040] The bottom vessel 2A has an outlet on its side wall 8 to which an outlet pipe 10 is connected to allow water to flow out of the tower structure to a circulation pump 12, circulate upwards to a filtration and / or disinfection tank 14, and return to the upper vessel 2B via an inlet pipe 16, again flowing downward through the system.

[0041] To this end, nutrient rich seawater is circulated continuously through the system during use, providing a flow of solution independent of the ocean or natural water source. The circulation can be stopped automatically or manually to allow the seaweed to dry within vessel 2 in order to remove any bacteria or viruses.

[0042] An air injector (not shown) is used to create turbulence and air bubbles in the seawater while it is circulating through the system.

[0043] One or more culture towers or tanks are installed within a building, such as a greenhouse, and provided with an automated climate control system to control temperature and lighting for optimal growth. Experiment 1 - Vegetative growth of selected seaweed species

[0044] Experiments were conducted to study the vegetative growth rates of two native species, Porphyra dioica and Porphyra purpurea, found on the west coast of Scotland, cultivated under different conditions.

[0045] Poprphyra dioica was present near Campbeltown on the Kintyre Peninsula in February, but at that time, it did not show much growth. By April of that year, at the same location, young gametophytes of Porphyra dioica were identified growing communally in dense clusters on the cliffs and boulders of a very exposed east-facing coast. In the intertidal zone for an area of ​​about 30 metres, Porphyra dioica appeared to be the only Porphyra species visible. Whole thallus including the attached roots were collected and transported to the laboratory as quickly as possible in a cooler box. The thallus was washed thoroughly in filtered, UV-irradiated seawater to remove epiphytes, dirt and organisms. Only sexually undifferentiated immature thallus, identified by undifferentiated marginal sporangial groups, was used for experiments to study maximum vegetative growth rates.

[0046] Porphyra purpurea was collected from a seaweed farm off the coast of the Sound of Kerrera near Oban in May and was found growing on polyester ropes deployed at the farm.

[0047] Porphyra dioica grows mainly in July and August, when the mean seawater temperature near the Oban area in 2011 was about 13 °C. For Porphyra purpurea, thallus formation is also common during summer in the British Isles. In the present experiment, the controlled temperature was set at 13-14 °C for both species.

[0048] The light conditions for the experiment were: light intensity near the surface water was 60 μmol m -2 s -1 The average light intensity on a cloudy day was approximately 50 μmol m -2 s -1 The optimal circadian photoperiod for Porphyra spp. in Japan is 10 hours. Porphyra dioica and Porphyra purpurea in Scotland are generally winter crops, while Porphyra dioica and Porphyra purpurea are spring and summer crops.

[0049] Previous studies have shown that reproductive activity of Poprphyra umbilicalis from Helgoland increases with a 12-h dark period and decreases with a 12-h light period, so the photoperiod in the experiment was set to 12 h light:12 h dark (8 a.m. to 8 p.m.).

[0050] Several types of nutrient-rich solutions have been used for the cultivation of Porphyra in Japan. The nutrient-rich solution chosen for the cultivation of both Porphyra species is applicable to most seaweeds and microalgae and is considered to be the most useful solution for other seaweed species cultivated at the same time.

[0051] Sterile Erlenmeyer flasks were set up using bubble plugs and 0.45um filters and glass pipettes, each containing 500mL of eutrophic seawater. Three replicates were cultured under both fast and slow bubble injection conditions.

[0052] Air was introduced via a glass pipette. A high-speed air bubble injection pipette produces more turbulence at a higher air flow rate per second than a low-speed air bubble injection. All Porphyra species were cultured in a constant temperature (CT) room at 13-14°C, 12 h light:12 h dark (8 am to 8 pm) with a light intensity of 60 umol m-2 s-1. The wet weight of the samples was recorded weekly using a precision weighing scale. The solution was changed at weekly intervals, at which time the wet weight measurements of the thallus pieces were recorded. To ensure consistency across experiments, the same drying procedure was used each time when measuring wet weight. Experiments with Porphyra dioica collected in May, Porphyra dioica collected in July, and Porphyra purpurea collected in May lasted for 42, 84, and 21 days, respectively.

[0053] Statistical analysis was used to investigate differences in growth rate of each Porphyra genus cultured under low-rate and high-rate aerated bubble injection conditions, as well as seasonal variation within the species Porphyra dioica.

[0054] In previous laboratory trial cultures, Porphyra dioica collected in July appeared to grow slower than those collected in May. Four maximum vegetative growth rates (SGR)% day of Porphyra dioica collected in May and July cultured under low and high air bubble injection conditions were -1 The mean value of SGR was determined from three replicates each (the maximum mean vegetative growth rate of the week with the greatest vegetative growth rate was used instead of the mean vegetative growth rate over the entire experimental period for each of the four categories because there were significant differences between the weekly SGRs in each category), and each result was analyzed by one-way ANOVA followed by Tukey's HSD analysis (α = 0.05) as a post-hoc test. Porphyra purpurea collected in May were cultured under low and high air bubble injection conditions, and the two maximum vegetative growth rates (% day -1 were analyzed by one-way analysis of variance (α = 0.05).

[0055] The weekly mean wet weight changes of both Porphyra species cultured under low and high rate air bubble injection conditions were analyzed by regression line using statistical applications Minitab® (Minitab® 15.1.0.0, PA, USA) and MATLAB® R2015b (The Mathworks, Inc., Natwick, MA, USA, 2015). And their weekly mean wet weight percent changes were presented in bar graphs and tables. For one-way ANOVA, normality of data was checked with normal probability plots, assumption of constant variance with residuals vs fitted plots, and independence with residuals vs order plots. SGR, expressed as vegetative growth rate per day, was calculated as follows: TIFF0007666941000001.tif1525 where FW1 and FW2 are the wet weights on days D1 and D2, respectively.

[0056] Two independent experiments were performed using Porphyra dioica collected in May and July as material, and both collections were cultured under slow and fast air bubble injection conditions. The experiments on vegetative growth rates of Porphyra dioica collected in May and July lasted for 42 and 84 days, respectively.

[0057] The mean and standard deviation of weekly wet weight percent change for Porphyra dioica collected in May are shown below. Mean weekly wet weight percent change of three replicates of Porphyra dioica collected in May 2015. Cultured under low and high air bubble injection conditions for 42 days at 13–14°C and 60 μmol m 2 light. -2 s -1 , photoperiod 12 h light:12 h dark (8:00 am-8:00 pm). Standard deviations of replicates are shown in italics. TIFF0007666941000002.tif2270TIFF0007666941000003.tif4681Mean weekly wet weight percent change (with standard deviation) for three replicates of Porphyra dioica collected in May 2015. Cultured under slow and fast air bubble injection conditions for 42 days at 13–14°C and 60 umol m light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm).

[0058] The results for Porphyra dioica collected in July of the same year are as follows: Mean weekly wet weight percent change of three replicates of Porphyra dioica cultivated for 84 days under slow and fast air bubble injection conditions, collected in July 2015, at 13–14°C and 60 umol m light. -2 s -1 , photoperiod 12 h light:12 h dark (8:00 am-8:00 pm). Standard deviations of replicates are shown in italics. TIFF0007666941000004.tif2286TIFF0007666941000005.tif4681Mean weekly wet weight percent change (with standard deviation) for three replicates of Porphyra dioica collected in July 2015, grown under slow and fast air bubble injection conditions at 13–14°C and 60 umol m light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm).

[0059] The mean starting masses of Porphyra dioica collected in May and cultured under low-rate air bubble injection conditions were 0.37g and 0.36g, respectively, while their maximum mean masses were 3.92g and 3.16g, respectively, at week 6. The minimum mean weekly wet weight percent changes were 0.7% and -3.3%, respectively, at week 5, while their maximum mean weekly wet weight percent changes were 214.7% and 145%, respectively, at week 1. The mean starting masses of Porphyra dioica collected in July and cultured under low-rate and high-rate air bubble injection conditions were 0.29g and 0.21g, respectively, while their maximum mean weekly wet weight percent changes were 3g and 2.69g, respectively, at week 12. The minimum mean weekly wet weight percent changes were 1.4% and 4.1%, respectively, at week 1, while their maximum mean weekly wet weight percent changes were 1-7.6% and 100.51%, respectively, at week 3.

[0060] Vegetative growth rates were calculated for the two experiments under the two conditions (see below). Weekly average vegetative growth rates of three replicates of Porphyra dioica cultivated for 84 days under slow and fast air bubble injection conditions, collected in July 2015, at 13–14°C and 60 umol m light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm). TIFF0007666941000006.tif16106Average weekly vegetative growth rates of three replicates of Porphyra dioica cultivated for 42 days under slow and fast air bubble injection conditions, collected in May 2015, at 13–14°C and 60 umol m 2 of light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm). TIFF0007666941000007.tif1660TIFF0007666941000008.tif4681Average weekly vegetative growth rates of three replicates of Porphyra dioica cultivated for 42 days under slow and fast air bubble injection conditions, collected in May 2015, at 13–14°C and 60 umol m 2 of light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm).

[0061] One-way ANOVA (α = 0.05) was performed to compare differences between the means of maximum vegetative growth rates. Maximum vegetative growth rate (% day ) of three replicates of Porphyra dioica collected under slow air bubble (SB) and fast air bubble (FB) injection conditions in May 2015 and July 2015. -1 Porphyra dioica samples collected in May 2015 and July 2015 were cultivated for 42 and 84 days, respectively, at 13–14°C and 60 μmol m 2 of light. -2 s -1 , photoperiod 12 h light:12 h dark (8:00 am-8:00 pm). Standard deviations of vegetative growth rates are shown in italics. TIFF0007666941000009.tif1258TIFF0007666941000010.tif4681Maximum vegetative growth rate (SGR) (% day -1 Porphyra dioica plants collected in May 2015 and July 2015 were cultivated for 42 and 84 days, respectively, at 13–14°C and 60 μmol m 2 of light.-2 s -1 , photoperiod 12 h light:12 h dark (8:00 am-8:00 pm). Standard deviations of vegetative growth rates are shown in italics.

[0062] This was followed by Tukey's HSD analysis (α = 0.05) as a post-hoc test to determine the probability of pairwise comparisons between the means of the maximum vegetative growth rates of the four experiments. The maximum vegetative growth rates of Porphyra dioica harvested in May 2015 and cultured for 42 days under low and high air bubble injection conditions were 7% day 1 in the first week, respectively. -1 and 5.5% day -1 The maximum vegetative growth rate of Porphyra dioica collected in July and cultured for 84 days under low and high air bubble injection conditions was 4.5% day in the third week, respectively. -1 and 4.3% day -1 A statistically significant difference was detected between the maximum mean vegetative growth rates of Porphyra dioica collected in May and July (p = 0.024). One-way ANOVA (α = 0.05) was performed to compare the differences in the mean values ​​of the highest vegetative growth rates for the four experiments. The experiment with Porphyra dioica collected in May 2015 was performed for 42 days under low and high air bubble injection conditions, and the experiment with Porphyra dioica collected in July 2015 was performed for 84 days under low and high air bubble injection conditions. The experiment was performed at 13–14°C and 60 umol m 2 of light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm). TIFF0007666941000011.tif2269

[0063] To quantitatively compare the wet weight changes of Porphyra dioica cultivated under low and high air bubble injection conditions, regression lines were plotted with 95% confidence intervals for the four experiments using Minitab and MATLAB®. TIFF0007666941000012.tif4974Regression lines of wet weight changes of three replicates of Porphyra dioica collected in May 2015 and cultured for 42 days under low-speed air bubble injection conditions at 13-14°C and 60 umol m 2 of light. -2 s -1 The photoperiod was 12 h light: 12 h dark. The average slope, the average wet weight change per day, was 0.08842 g day -1 It is. TIFF0007666941000013.tif4974Regression curves of wet weight changes for three replicates of Porphyra dioica harvested in May 2015. They were cultured for 42 days under high-velocity air bubble injection conditions at 13-14°C and 60 umol m 2 of light. -2 s -1 The photoperiod was 12 h light: 12 h dark. The average slope, the average wet weight change per day, was 0.07417 g day -1 It is. TIFF0007666941000014.tif55142Regression lines of wet weight change of Porphyra dioica cultivated under slow and fast air bubble injection conditions collected in May and July 2015 (graphs drawn using Matlab® R2015b). The experiment for Porphyra dioica collected in May 2015 lasted for 42 days under slow and fast air bubble injection conditions, and for Porphyra dioica collected in July 2015 lasted for 84 days under slow and fast air bubble injection conditions. At 13-14°C and 60 uumol m 2 of light, -2 s -1 , photoperiod 12h light:12h dark.

[0064] The average wet weight change of Porphyra dioica collected in May during 42 days of incubation under low and high air bubble injection conditions was 0.08842 g day-1, respectively. -1 and 0.07417g day -1 The average wet weight change of Porphyra dioica collected in July and cultured for 84 days under low and high air bubble injection conditions was 0.03544 g day-1, respectively. -1 and 0.03185g day -1 It was.

[0065] Comparing all the slope estimates of the regression lines, it is reasonable to assume that Porphyra dioica collected in May may be best suited for cultivation under low-rate air bubble injection conditions.

[0066] The experiment on Porphyra purpurea cultured under slow and fast air bubble injection conditions lasted only 21 days because all weights dramatically decreased in the third week due to tissue fragmentation without exception. The table and figure below show the results of Porphyra purpurea cultured under slow and fast air bubble injection conditions in terms of weekly wet weight percent change with standard deviation. The average starting mass of Porphyra purpurea harvested in May and cultured under slow and fast air bubble injection conditions was 0.36g and 0.34g, respectively, the average maximum mass in the second week was 1.91g and 1.54g, respectively, the minimum average weekly wet weight percent change was -72.2% and -55.4%, respectively, in the third week, and the maximum average weekly wet weight percent change was 232.9% and 260.8%, respectively, in the first week. Average weekly percent wet weight change of three replicates of Porphyra purpurea grown for 21 days under slow and fast air bubble injection conditions at 13–14°C and 60 μmol m 2 of light. -2 s -1 , photoperiod 12 h light:12 h dark (8:00 am-8:00 pm). Standard deviations of the replicate means are shown in italics. TIFF0007666941000015.tif2245TIFF0007666941000016.tif4681Weekly average of percent wet weight change of Porphyra purpurea collected in July 2015, cultured under low and high air bubble injection conditions for 21 days at 13-14°C and 60 umol m -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm). TIFF0007666941000017.tif4974Regression lines of wet weight changes of three replicates of Porphyra dioica collected in July 2015 and cultured for 84 days under slow air bubble injection conditions at 13-14°C and 60 umol m 2 of light. -2 s -1 The photoperiod was 12 h light: 12 h dark. The average slope, the average wet weight change per day, was 0.03544 g day -1 It is. TIFF0007666941000018.tif4974Regression curves of wet weight change for three replicates of Porphyra dioica collected in July 2015. They were cultured for 84 days under high-velocity air bubble injection conditions at 13-14°C and 60umol m -2 s -1 The photoperiod was 12 h light: 12 h dark. The average slope, the average wet weight change per day, was 0.03185 g day -1 It is.

[0067] The average weekly vegetative growth rates of the three experimental replicates were calculated and graphed. Weekly average vegetative growth rates of three replicates of Porphyra purpurea collected in May 2015, cultured for 21 days under slow and fast air bubble injection conditions at 13–14°C and 60 μmol m 2 of light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm). TIFF0007666941000019.tif1642TIFF0007666941000020.tif4681Average weekly vegetative growth rates of three replicates of Porphyra purpurea harvested in May 2015, cultured under slow and fast air bubble injection conditions for 21 days at 13–14°C and 60 umol m 2 of light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm).

[0068] The average maximum vegetative growth rate of Porphyra purpurea cultured under low and high air bubble injection conditions was calculated and graphed, and the standard deviation was also calculated. Maximum vegetative growth rates (% day ) of three replicates of Porphyra purpurea cultivated for 21 days under low and high air bubble injection conditions. -1 ) mean and standard deviation. 13-14℃, light intensity 60uumol m -2 s -1 , photoperiod 12h light:12h dark. TIFF0007666941000021.tif1539TIFF0007666941000022.tif4681Vetigineous growth rates (% day -1 ) at 13-14℃ and 60μmol m -2 s -1 , photoperiod 12h light:12h dark.

[0069] One-way ANOVA (α = 0.05, t-test with two groups) was performed to compare the difference between the two means of the maximum vegetative growth rate of Porphyra purpurea cultivated under the slow and fast air bubble injection conditions. No statistically significant difference was detected between the means of the maximum vegetative growth rate of Porphyra purpurea cultivated under the slow and fast air bubble injection conditions (p = 0.926). The maximum vegetative growth rate of Porphyra purpurea harvested in May and cultivated for 21 days under the slow and fast air bubble injection conditions was 7.4% day-1 and 7.8% day-2 in the first week, respectively. -1 It was. One-way ANOVA (α = 0.05) was performed to compare the differences between the means of the maximum vegetative growth rates of four experiments of Porphyra purpurea cultured under low and high air bubble injection conditions for 21 days at 13–14°C and 60 μmol m light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm). TIFF0007666941000023.tif2072

[0070] To quantitatively compare the vegetative growth rates of Porphyra purpurea cultivated under low and high air bubble injection conditions, regression lines were drawn with 95% confidence intervals using Minitab. The average wet weight change of Porphyra purpurea harvested in May and cultivated for 21 days under low and high air bubble injection conditions was plotted. A third order approximation equation was used, and the slope on the 7th day indicated the average daily wet weight change in the first week, which was 0.132 g day , respectively. -1 and 0.101g day -1 was calculated by differentiating the equation. TIFF0007666941000024.tif4974Regression curves of wet weight change for three replicates of Porphyra purpurea cultivated for 21 days under slow air bubble injection conditions at 13-14°C and 60 umol m -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm). TIFF0007666941000025.tif4974Regression curves of wet weight change for three replicates of Porphyra purpurea cultivated for 21 days under high-velocity air bubble injection conditions at 13-14°C and 60 umol m 2 of light. -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm). TIFF0007666941000026.tif46115Regression curves of wet weight changes of Porphyra purpurea cultivated under low and high air bubble injection conditions, collected in May 2015 (graphs drawn using Matlab® R2015b). 13-14°C, 60 umol m -2 s -1 , photoperiod 12h light:12h dark (8:00am-8:00pm).

[0071] The results showed that Porphyra purpurea appeared to grow significantly faster (from juvenile leaves to mature thallus in about 20 days) than Porphyra dioica (from juvenile leaves to mature thallus in about 40 days) collected in May in West and McBride's Modified ES medium (WMMES) solution derived from Provasoli's ES solution containing Ge02. Porphyra purpurea appears to be more suitable for mobile land-based seaweed culture devices than Porphyra dioica.

[0072] The shorter the incubation time, the less nutrients are needed, and therefore the less frequent the culture solution needs to be changed. It is known that the net photosynthetic efficiency of biomass in some marine algae species, such as Zonaria farlowii and Dictyopteris undulata, increases with increasing surface area / volume ratio. This is consistent with the results showing a higher vegetative growth rate in Porphyra purpurea, which has a thinner, single-layered thallus tissue than Porphyra dioica.

[0073] The experimental results show that the vegetative growth rates are significantly different between Porphyra dioica collected in May and July. Whether cultivated under slow or fast air bubble injection conditions, Porphyra dioica collected in May appeared to grow faster from juvenile leaves to mature thallus in about 40 days compared to Porphyra dioica collected in July, which grew from juvenile leaves to mature thallus in about 80 days.

[0074] One possible reason for this result is that only slow-growing genotypes of Porphyra dioica were unintentionally collected in July. In both experiments with Porphyra dioica collected in May and July, only juvenile and unsexualized thallus was collected, and it is reasonable to assume that the Porphyra dioica collected in July germinated at the same time as those collected in May. The Porphyra dioica collected in July may have grown relatively slower than those collected in May.

[0075] The air bubble injection device used in this system creates turbulent motion of the solution (nutrient-rich seawater) which accelerates vegetative growth by increasing nutrient flux into the thallus, as it reduces the depth of the diffuse boundary layer at the surface of the thallus. The turbulence also exposes the thallus to light, increasing the amount of OH - By removing ions, photosynthetic activity is increased. OH - Ions inhibit photosynthesis when they accumulate on the thallus surface. Experiments carried out on Ulva showed that biomass yield with continuous air bubble injection was significantly higher than with intermittent air bubble injection at 15 s min-1. Experiments on Chondrus nigricans showed that interrupting the air bubble injection system at night increased growth rate by 146%. Interruption did not affect growth rate or nitrogen and carbon removal in Chondrus crispus and Palmaria palmata.

[0076] The aquaculture equipment in this system is constructed with a large surface area and shallow depth to facilitate CO2 exchange at the medium surface. Neopyropia yezoensis and Porphyra haitanensis promote photosynthesis under high CO2 concentrations. This can be achieved under high-rate air bubble injection conditions, resulting in improved growth rates. Photosynthetic carbon fixation increases pH due to a decrease in dissolved inorganic carbon (DIC) accompanied by an increase in OH-, which results in atmospheric CO2 dissolving in the medium. Photoautotrophic seaweeds in seawater also absorb atmospheric CO2. For example, the oxygen consumption in respiration of seaweeds such as Porphyra amplissima is much less than the oxygen production in photosynthesis under dark conditions compared to the oxygen consumption under light conditions.

[0077] When seaweed is grown near fish farms, it absorbs the nutrients nitrogen and phosphorus that are released, reducing the environmental burden of fish farming while providing a valuable resource of seaweed.

[0078] Porphyra not only has a high growth rate and high nitrogen content, but also produces economically valuable biomass for human consumption and biochemical applications. Generally, NH4+ is the main nitrogen source in fish farm wastewater. In this experiment, NO 3- was used as the nitrogen supply, and although its concentration was 453 μM, NH 4+ No significant difference was found between the biofiltration efficiency of NO3+ by Porphyra purpurea and Porphyra dioica. Thus, Porphyra purpurea appears to be a good candidate for reducing the nitrogen load in fish farm effluents, as it grows rapidly at high nitrogen concentrations. Furthermore, up to 10% of Porphyra dioica can be effectively included in the diet of rainbow trout without significant negative effects on weight or growth performance. This also makes this species a suitable candidate for IMTA systems from a commercial point of view, as intensively fed monospecies aquaculture costs approximately 50% of the total running costs. Experiment 2 - Cultivation of the Conchocelis Generation

[0079] Most research programs on the Porphyra genus do not include aquaculture, a key component in scaling up findings for commercial purposes: from an economic standpoint, it is not feasible for Nori farmers to perform laboratory cultures and store free conidia.

[0080] Moreover, regular replacement of the culture solution under controlled, sterile conditions is very time-consuming. Moreover, to cultivate Nori on an industrial scale, bunches of free filaments are chopped, sown, and cultured on shells. In the case of Porphyra dioica, found in Porto, Portugal, it takes an additional 22.5 weeks from conchocelis formation to conchospore release. In Japan, Nori farmers can purchase selectively bred free filament seeds produced by fisheries research stations or Nori farming companies within the local municipality. Therefore, a major challenge for small-scale Nori producers (especially in Western countries) is how to avoid the high culture management costs in the cultivation of free / shell filaments.

[0081] Cultures of conchoconids of Japanese Porphyra species survive for several years in low light conditions. The occurrence of thallus of Porphyra dioica and Porphyra purpurea in the UK throughout the year suggests that the conchoconid stage is an important perennial phase, adapted to a wide range of environmental factors. Furthermore, photoperiod, light intensity, temperature and water velocity can control the conversion of conchosporangia maturation to conchospore release. For example, relatively high seawater temperatures and static water movement inhibit conchospore release.

[0082] Successful production of Nori in this system requires an innovative approach that combines cost-effective and storable culture techniques of conchospores with a continuous supply of reliable conchospores throughout the year. Applicant's experiments were designed to investigate cost-effective ways to maintain the maturation stage of conchospores over time by modifying the culture conditions, to promote conchospore maturation at the right time, and to trigger conchospore release throughout the year. In the case of Porphyra dioica from Porto, Portugal, the transformation from conchospore maturation to conchospore release takes less than 11 weeks.

[0083] Mature dioecious gametophytes were collected in April from densely packed rock faces and boulders near Campbeltown on the Kintyre peninsula on the west coast of Scotland. Whole thallus were harvested from the rocks by manually removing the attached roots. They were then washed extensively in filtered, UV-irradiated seawater to remove other seaweeds, sand grains, and small organisms.

[0084] The experiment consisted of three parts: first, to identify the appropriate conchosporangium culture storage conditions to maintain the maturity of conchosporangium over a long period of time, hereafter referred to as "conchosporangium for storage"; second, to find the optimal culture conditions to promote maturation of conchosporangium. Second, the search for a suitable material for zygospores to settle and grow into conchosporangium was also the motivation for the experiment. Free conchosporangium was cultured without added nutrients.

[0085] Mature thalli of Porphyra dioica collected in May from the Kintyre Peninsula were placed on clean tissue paper and air-dried overnight to induce desiccation stress and release zygospores when re-immersed in seawater. The following day, the dried thalli were placed in a 54-litre white plastic box containing approximately 30 litres of filtered, UV-irradiated seawater with scallop and oyster shells on the bottom.

[0086] Porphyra purpurea collected from a seaweed farm in May were cultured in filtered, UV-irradiated, tindalized seawater for a week and then bubbled to induce the release of zygospores. Zygospores were extracted by filtration using a 40-40 μm pore size filter felt and placed in a 54-L white plastic box containing 30 L of filtered, UV-irradiated seawater with scallop and oyster shells at the bottom.

[0087] The challenge was to maintain storage conidia at an early stage of conidial maturity over the long term. Conidia of both Porphyra species were cultured monthly in filtered, UV-irradiated seawater at 12–13°C and in light levels of 5–10 umol m−1. -2 s -1 The shells were cultured under a 16h light:8h dark photoperiod and without air bubble injection for periods of approximately 12 and 10 months, respectively. Fifteen oyster and fifteen scallop shells were cultured in each experiment with the inner shell side facing up. All shells were pretreated two days prior to the experiment by immersing them in a diluted solution of Decon® 90, which is biodegradable and disinfectant.

[0088] Subsequently, experiments were carried out to identify the optimal culture conditions to accelerate the maturation of conchosporangia using the preserved conchosporangia by comparing, first, the presence or absence of nutrients, second, different light intensities, and third, the presence or absence of air bubble injection.

[0089] First, to investigate the effect of nutrients on the maturation of conchosporangia in the preserved shell filaments, four preserved scallop shell filaments and four preserved oyster shell filaments of Porphyra dioica, and an equal number of preserved Porphyra purpurea, were cultured with or without nutrients. Two oyster shell filaments and two scallop shell filaments, which had been used to culture the preserved shell filaments of each Porphyra species, were cultured without nutrients in 300 mL of filtered, UV-irradiated seawater, and the remaining preserved shell filaments were cultured in 300 mL of WMMES solution containing GeO2 at 13–14°C and 15–25 μmol m 2 light. -2 s -1 The plants were cultured under a photoperiod of 12 h light:12 h dark for approximately 20 days.

[0090] Second, the effect of light intensity on maturation of conchosporangia in preserved shell filaments of Porphyra dioica and Porphyra purpurea was investigated. Four preserved oyster shell filaments and four preserved scallop shell filaments were grown under dark conditions with a light intensity of less than 5 μmol m−2 s−1, while the others were grown under a light intensity of 50–60 μmol m−2 s−1. -2 s -1 The plants were cultured under light conditions of 12 h light:12 h dark with a photoperiod of 12 h light:12 h dark at 13-14°C for approximately 50 days, with 300 mL of WMMES solution containing GeO2 replaced monthly.

[0091] Third, the effect of air bubble injection on maturation of conchosporangia in preserved shell filaments of Porphyra dioica and Porphyra purpurea was investigated. Four preserved oyster shell filaments and four preserved scallop shell filaments were incubated in WMMES solution supplemented with GeO2 at 13–14°C under light conditions of 15–25 μmol m−1. -2 s -1 Four preserved oyster shell filaments and four preserved scallop shell filaments were cultured in WMMES solution supplemented with GeO2 at 13–14°C under light conditions of 15–25 μmol m−1 and a photoperiod of 12 h light:12 h dark with air bubbles injected. -2 s -1 The plants were cultured under a photoperiod of 12 h light:12 h dark without any air bubble injection. The experiment lasted for approximately 18 days.

[0092] In addition to glass slides, synthetic felt material, and fine and coarse oyster shell grits were tested as substrates for the colonization of zygospores of Porphyra purpurea. The felts, with or without chemical treatment, were soaked overnight in a solution of sodium carbonate prepared in distilled water at pH 10 with a mixture of sodium bicarbonate and sodium hydroxide. Duplicate pieces of synthetic felt material and oyster shell grit were placed in 500 mL of WMMES solution containing GeO2, changed monthly, inoculated with zygospores, and exposed to a light intensity of 15–25 μmol m−1. -2 s -1 , and cultured under a photoperiod of 12 h light:12 h dark.

[0093] Thallus of Porphyra purpurea was incubated in UV-irradiated and tindalized seawater for 1 week before releasing zygospores, which were collected and extracted with a 40 μm pore size filter felt. Furthermore, zygospores of Porphyra purpurea were incubated in three Petri dishes with one glass slide each in 30 mL of WMMES solution containing GeO2. The next day, the glass slide was transferred to the other Petri dish and a new WMMES solution containing GeO2 was used to select for established zygospores and to exclude other epiphytes. These were incubated in a light regime of 15–25 μmol m−1 and 10–20 μmol m−1. -2 s -1 The plants were cultured for approximately 3 months at 13-14°C under a photoperiod of 12 h light: 12 h dark. The solution was replaced monthly.

[0094] Mature thallus of Porphyra dioica were thoroughly washed, placed on clean tissue paper, and air-dried overnight. The next day, the dried thallus was re-immersed in filtered, UV-irradiated, tindalized seawater to release zygospores. Zygospores of Porphyra purpurea were released from thallus of Porphyra purpurea in filtered, UV-irradiated, tindalized seawater after 1 week of incubation, collected, and extracted with a 40-um pore size filter felt. Spores of each Porphyra species were cultured in triplicate in three Petri dishes containing 30 mL of nutrient-free, filtered, UV-irradiated seawater at 12–13°C and 5–10 umol m light.-2 s -1 The plants were cultured under a 16-h light:8-h dark photoperiod without air bubbles. The medium was changed monthly.

[0095] After further detailed experiments, the following results were observed:

[0096] The fastest growth of shell filaments of Porphyra dioica occurs at 13–14°C and in light levels of 15–25 μmol m -2 s -1 It was found that the effect was achieved by culturing the plants in WMMES medium containing GeO2 with a photoperiod of 12h light:12h dark for 20 days.

[0097] The shell filaments of Porphyra dioica were grown at 13-14°C and 15-25 μmol m -2 s -1 After transfer to culture conditions with a photoperiod of 12 h light:12 h dark and nutrients added, maturation of conchosporangia was dramatically accelerated compared to culture conditions where no nutrients were added.

[0098] The preserved shell conidiophores of Porphyra purpurea were also grown under the experimental conditions of 13–14°C and 15–25 μmol m -2 s -1 After transfer to nutrient-containing medium with a 12-h light:12-h dark photoperiod, maturation of conchosporangia was dramatically accelerated compared to nutrient-free culture conditions.

[0099] In WMMES medium containing GeO2 at 13-14°C, there was no significant difference in the acceleration of conchosporangium maturation in both Porphyra dioica and Porphyra purpurea when cultured under light or dark light conditions. However, under light culture conditions, the growth of epiphytes was more prominent than that under dark culture conditions. Thus, dark culture appears to be more suitable.

[0100] The maturation of conchosporangia was not significantly affected by the presence or absence of air bubble injection.

[0101] There was no significant difference in the acceleration of maturation of conchosporangia of Porphyra purpurea between the culture conditions with and without air bubble injection.

[0102] Epiphytic growth was prominent in all cases studied, and compared with shell filament cultures of Porphyra purpurea, filaments did not grow well on the other substrates.

[0103] In contrast to experiments with the settlement of zygospores of Porphyra purpurea on several non-shell substrates, no significant growth of epiphytes was observed during shell filament cultures.

[0104] After extensive research and experimentation, the applicant has concluded that large-scale production of Nori in mobile land-based seaweed farming units is feasible.

[0105] Overall culture production of the biphasic Porphyra species in this system is less dependent on the vagaries of climate change, reduces physical labor and working hours offshore, and reduces unsustainable economic and environmental burdens.

[0106] A suitable method for maintaining stock shell conchoids of Porphyra dioica and Porphyra purpurea is to maintain them in filtered, UV-irradiated seawater at 12–13°C with monthly changes and a light level of 5–10 umol m -2 s -1 The culture conditions were found to be less than 16 h light:8 h dark, with a photoperiod of 16 h light:8 h dark, and without air bubble injection. Oyster and scallop shells should be pretreated for 2 days before starting the conchoidal culture by soaking them in a diluted solution of Decon(R)90, which has biodegradable and bactericidal properties.

[0107] Based on the results of the experiments on how to promote maturation of conchosporangia of shell filaments, the optimal strategy for promoting maturation of conchosporangia of preserved shell filaments of both Porphyra dioica and Porphyra purpurea is as follows: on WMMES medium containing GeO2 at 13–14°C under light intensity of 15–25 μmol m 2 -2 s-1 The photoperiod was 12h light:12h dark and the plants were cultured for 20 days. Optimal culture conditions for promoting maturation of conchosporangia of preserved shell filaments. TIFF0007666941000027.tif1979

[0108] Increasing seawater temperature to 24°C accelerates the maturation of shell filaments of Japanese Porphyra yezoensis and Porphyra asakusa. The culture conditions for the preserved shell filaments in this experiment were cooler, darker, longer-daylight, and nutrient-free than those for Porphyra dioica in Porto, Portugal, allowing the early maturation of the shell filaments to be maintained for a longer period. The strategy was successful.

[0109] Based on these results and a set of assumptions, a biphasic Porphyra species food production system utilizing mobile land-based seaweed farming devices is productive, sustainable, less dependent on the vagaries of climate change, time-saving, and reduces offshore physical labor and unsustainable economic and environmental burdens.

Claims

[Claim 1] A central post is provided upright on the foundation; A vessel for storing seawater, the vessel being formed by a substantially sector-shaped bottom and a side wall extending upright from the periphery of the bottom; the substantially sector-shaped bottom and the central side of the side wall of the vessel are fixed in a stepped and spiral manner along the outer circumferential surface of the central post, with six vessels going around the central post three times, with the vertical and horizontal positions of the upper and lower vessels being offset from top to bottom, and the system includes a filter and / or disinfectant tank for filtering and / or disinfecting seawater while seawater falls sequentially from the topmost upper vessel to the bottommost bottom vessel, and the seawater that reaches the bottom vessel is pumped back to the upper vessel and circulated by falling again from the upper vessel to the lower bottom vessel, and further includes a filter and / or disinfectant tank for filtering and / or disinfecting seawater while circulating nutrient-rich seawater within a closed system of the system, and injecting air bubbles into the seawater flow of the system, Furthermore, the system has a function of controlling the temperature of the seawater and lighting to irradiate the seawater, and the mobile land-based seaweed cultivation device is characterized in that it grows seaweed contained in each of the containers.

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