Method for acclimatizing saltwater shrimps, and method for growing saltwater shrimps by aquaponics

Abstract

[Problem] To provide a method for acclimatizing saltwater shrimps, a method for growing saltwater shrimps by an aquaponics, a system for acclimatizing saltwater shrimps, and an aquaponics, with which it becomes possible to improve the efficiency of land-based aquaculture of saltwater shrimps and surely promote the growing of saltwater shrimps. [Solution] This method for acclimatizing saltwater shrimps A to a low-salt environment is characterized by including a salt concentration reduction step for reducing the salt concentration in rearing water 111 in which the saltwater shrimps A are reared, wherein the salt concentration in the rearing water 111 is reduced by 0.10-0.50 mass% per day. This system 1 for acclimatizing saltwater shrimps is provided with: a storage part 11 for storing rearing water 111 in which the saltwater shrimps A are reared; and a salt concentration reduction part 12 for reducing the salt concentration in the rearing water 111 stored in the storage part 11, wherein the salt concentration in the rearing water 111 is reduced by 0.10-0.50 mass% per day. The rearing water 111 is made into rearing water 112 having a lower salt concentration than that in the rearing water 11 through the salt concentration reduction part 12.

Description

Methods for acclimatizing saltwater shrimp and cultivating them using aquaponics

[0001] The present invention relates to a method for acclimatizing saltwater shrimp to low-salinity rearing water that has a lower salt concentration than seawater, and to an aquaponics cultivation method in which saltwater shrimp are hydroponically cultivated using the low-salinity rearing water.

[0002] Land-based aquaculture methods for crustaceans have been studied. Saltwater shrimp are known for their rapid growth, taking approximately 3 to 4 months for them to grow from 0.5 cm juvenile shrimp to 12 to 15 cm edible shrimp. Vannamei shrimp, in particular, is gaining attention for its environmental adaptability, disease resistance, and growth rate. Its ability to grow on low-protein feed, high protein content after maturation, and its ability to survive long periods outside of water make it a profitable option. However, in Japan, saltwater shrimp aquaculture is currently carried out using closed-loop or free-flowing land-based aquaculture methods using seawater or aquatic water with a salinity equivalent to seawater. This limits the feasible areas to areas close to the sea, and further incurs costs for proper water quality management. Therefore, there is a strong demand for a shrimp cultivation method that can be used in a freshwater-like or completely freshwater environment with a lower salinity.

[0003] Patent Document 1 discloses a method for cultivating edible saltwater shrimp using rearing water with a salinity of 1 to 10 ppt (1 to 10‰ = 0.1 to 1.0%).

[0004] Japanese Patent Application Laid-Open No. 2008-43252

[0005] Patent Document 1 discloses a method in which shrimp are gradually acclimated to low salinity by gradually replacing the rearing water with seawater, with the final salinity being reached in one day at 0.5% (5 ppt) and in 3 to 7 days at 0.1% (1 ppt) (see paragraphs

[0027] -

[0028] of the specification). Furthermore, with regard to the relationship between salinity and shrimp growth rate, the results show that a group of shrimp reared in seawater with a salinity of 3% (30 ppt) and a group of shrimp reared in rearing water with a salinity of 0.5% (5 ppt) had higher weight gain rates, total body growth rates, and survival rates than two groups reared in low salinity waters with salinities of 0.15% (1.5 ppt) and 0.2% (2 ppt) (see paragraph

[0057] of the specification and Figure 2).

[0006] Here, when shrimp are adapted to a low salinity concentration, the survival rate of the shrimp depends on the amount of reduction in salinity per day, but Patent Document 1 does not disclose this point, and therefore it is not possible to improve the efficiency of land-based aquaculture by increasing the survival rate of shrimp. Furthermore, the method disclosed in Patent Document 1 has the problem that it is not possible to improve the growth rate of shrimp in low-salinity environments, including completely freshwater environments (salinity of 0.05% or less) and environments similar to freshwater (salinity of less than 0.5%), compared to seawater environments.

[0007] The present invention has been devised in view of the above-mentioned problems, and an object of the present invention is to provide a method for acclimatizing saltwater shrimp, an aquaponics cultivation method, a saltwater shrimp acclimatization system, and an aquaponics system that can improve the efficiency of land-based culture of saltwater shrimp and reliably promote their growth.

[0008] The method for acclimatizing saltwater shrimp in the first invention is characterized by comprising a salt concentration reducing step of reducing the salt concentration of rearing water in which the saltwater shrimp are reared by 0.10 to 0.50 mass % per day.

[0009] The saltwater shrimp acclimatization method of the second invention is characterized in that, in the first invention, the salinity concentration reduction step generates oxygen microbubbles or oxygen nanobubbles by blowing a gas containing at least oxygen into the rearing water.

[0010] The method for acclimatizing saltwater shrimp according to the third aspect of the present invention is the method according to the first or second aspect of the present invention, characterized in that the salt concentration reducing step reduces the salt concentration of the rearing water under irradiation with green light.

[0011] The saltwater shrimp acclimatization method of the fourth invention is characterized in that, in the first or second invention, the salt concentration reduction step reduces the salt concentration of the rearing water in a storage section in which artificial aquatic plants have been placed in advance.

[0012] The method for acclimatizing saltwater shrimp according to the fifth aspect of the present invention is the method according to the first or second aspect of the present invention, wherein the rearing water has a solute mass of 35 to 320 mg Mg per 1 L of the rearing water before and after the salt concentration reduction step. 2+ and 25-250 mg of Ca. 2+ and 8 to 80 mg of K. + and K + Mg relative to the mass of 2+ a first mass ratio indicating a mass ratio of + Ca relative to the mass of 2+ The second mass ratio is 0.5 to 5.0, and Ca 2+ Mg relative to the mass of 2+ The third mass ratio, which indicates the ratio of the masses of the above, is 0.7 to 1.4.

[0013] The aquaponics cultivation method of the sixth invention is characterized by comprising: a salt concentration reduction step of reducing the salt concentration of breeding water in which saltwater shrimp are raised by 0.10 to 0.50 mass % per day; a decomposition solution production step of producing a decomposition solution by biodegrading excrement of the saltwater shrimp; and a decomposition solution supplying step of supplying the decomposition solution produced in the decomposition solution production step to a plant that is hydroponically cultivated using the breeding water whose salt concentration has been reduced in the salt concentration reduction step.

[0014] According to the first to sixth inventions, a salinity reduction step is provided in which the salinity of the rearing water in which saltwater shrimp are reared is reduced by 0.10 to 0.50 mass% per day. This allows saltwater shrimp to be efficiently acclimatized to a low-salinity environment. This improves the efficiency of land-based aquaculture of saltwater shrimp. Furthermore, the weight of saltwater shrimp can be increased more efficiently than in seawater. This reliably promotes the growth of saltwater shrimp.

[0015] In particular, according to the second invention, the salinity reduction step generates oxygen microbubble water or oxygen nanobubble water by blowing at least oxygen-containing gas into the rearing water, which allows the saltwater shrimp to efficiently increase their weight and thereby reliably promote further growth of the saltwater shrimp.

[0016] In particular, according to the third aspect of the present invention, the salt concentration reducing step reduces the salt concentration of the rearing water while irradiating the rearing water with green light, thereby enabling the saltwater shrimp to efficiently increase in weight, thereby ensuring further growth promotion of the saltwater shrimp.

[0017] In particular, according to the fourth aspect of the present invention, the salt concentration reducing step reduces the salt concentration of the rearing water in the housing section in which artificial aquatic plants have been placed in advance, thereby improving the survival rate of saltwater shrimp and further improving the efficiency of land-based aquaculture of saltwater shrimp.

[0018] In particular, the fifth invention includes a salt concentration reduction step of reducing the salt concentration of rearing water in which saltwater shrimp are reared by 0.10 to 0.50 mass% per day, a decomposition solution production step of biodegrading shrimp excrement to produce a decomposition solution, and a decomposition solution supply step of supplying the produced decomposition solution to plants hydroponically grown in the rearing water with the reduced salt concentration. This allows for efficient increases in the weight of saltwater shrimp and plants. This ensures the growth of saltwater shrimp and plants that are sensitive to salt damage or can grow in freshwater at the same time.

[0019] In particular, according to the sixth aspect of the present invention, the rearing water has a Mg concentration of 35 to 320 mg before and after the salt concentration reduction step. 2+and 25-250 mg of Ca. 2+ and 8 to 80 mg of K. + The first mass ratio is 0.7 to 5.0, the second mass ratio is 0.5 to 5.0, and the third mass ratio is 0.7 to 1.4. This allows the survival rate of saltwater shrimp to be 75% or more, thereby further improving the efficiency of land-based saltwater shrimp farming.

[0020] Fig. 1 is a schematic diagram showing an example of an acclimation system used in the saltwater shrimp acclimation method of this embodiment. Fig. 2 is a flowchart showing an example of the saltwater shrimp acclimation method of this embodiment. Figs. 3(a) and 3(b) are schematic diagrams showing an example of the saltwater shrimp acclimation method of this embodiment. Fig. 4 is a schematic diagram showing an example of an aquaponics cultivation method using saltwater shrimp acclimated by the saltwater shrimp acclimation method of this embodiment. Fig. 5 is a flowchart showing an example of an aquaponics cultivation method using saltwater shrimp acclimated by the saltwater shrimp acclimation method of this embodiment.

[0021] Hereinafter, with reference to the drawings, a detailed description will be given of an embodiment of the method for acclimatizing saltwater shrimp A, a cultivation method using aquaponics 2, an acclimation system 1 for saltwater shrimp A, and an example of the aquaponics system 2. Note that the components in each drawing are shown schematically for the purpose of explanation, and for example, the size of each component and the size comparison between components may differ from those shown in the drawings.

[0022] (Method for acclimatizing saltwater shrimp A) An example of the method for acclimatizing saltwater shrimp A in this embodiment will be described with reference to Figures 1 to 3. First, an acclimatization system 1 used in the method for acclimatizing saltwater shrimp A in this embodiment will be described.

[0023] <Acclimation System 1> The acclimation system 1 is an apparatus for cultivating saltwater shrimp A. As shown in Fig. 1 , the acclimation system 1 includes a housing unit 11 and a salinity concentration reduction unit 12. The acclimation system 1 may further include a filtration device 51, a disinfection device 52, an air bubble generation device 53, a water quality monitoring device 54, a temperature control device 55, an automatic feeding device 56, a lighting unit 57, and artificial aquatic plants 6.

[0024] The acclimation system 1 is used in areas where it is difficult to obtain seawater, such as land-based aquaculture. The acclimation system 1 may be, for example, a flow-through system in which seawater or water with a lower salinity than seawater is continuously drawn into the storage unit 11, or a closed circulation system in which the water in the storage unit 11 is circulated.

[0025] <Storage Unit 11> The storage unit 11 stores the breeding water 110 and the saltwater shrimp A. The storage unit 11 is, for example, a fish preserve or an aquarium that stores the saltwater shrimp A.

[0026] A circulation pipe 31 for circulating drained water is connected to the storage unit 11. Rearing water 110 is circulated through the storage unit 11 via the circulation pipe 31. A known water supply pipe such as a polyethylene pipe may be used as the circulation pipe 31.

[0027] The storage unit 11 is connected to, for example, a water supply pipe 32 for supplying water into the storage unit 11. The storage unit 11 may be supplied with water from the salt concentration reducing unit 12 via, for example, the water supply pipe 32. As the water supply pipe 32, for example, a water supply pipe of the same quality as the circulation pipe 31 may be used.

[0028] The storage unit 11 is connected to, for example, a drainage pipe 33 for discharging water from the storage unit 11. The storage unit 11 may drain water to, for example, the salt concentration reduction unit 12 via the drainage pipe 33. As the drainage pipe 33, for example, a water supply pipe of the same quality as the circulation pipe 31 may be used.

[0029] The storage unit 11 is supplied with water that has been filtered through, for example, a filtration device 51. The storage unit 11 is supplied with water that has been disinfected through, for example, a disinfection device 52.

[0030] <Breeding Water 110> The breeding water 110 is breeding water whose salinity has been reduced by the salinity reduction unit 12. The breeding water 110 has a salinity of, for example, approximately 0.007 to 0.500% by mass, which is lower than the salinity of seawater (approximately 3.400% by mass). The example in FIG. 1 shows the state after saltwater shrimp A, which would not normally be able to survive in the salt concentration of the breeding water 110, has become acclimated to the salt concentration of the breeding water 110. This is because the salt concentration reduction unit 12 gradually reduces the salinity of breeding water (breeding water 111 described below) with a salinity sufficient for marine organisms to survive under predetermined conditions while the saltwater shrimp A is being reared, to obtain breeding water 110 with a salinity of approximately 0.007 to 0.500% by mass. Details of the method for acclimating saltwater shrimp A to the breeding water 110 will be described later.

[0031] The breeding water 110 contains, as a main component, for example, Mg 2+ (Magnesium ion), Ca 2+ (Calcium ion), K + (potassium ion), SO4 2- (sulfate ions), including

[0032] The breeding water 110 contains, for example, Mg as the mass of solute per 1 L of breeding water. 2+ is less than 35 mg or more than 320 mg, Ca 2+ is less than 25 mg or more than 250 mg, K + If the solute content is less than 8 mg or more than 80 mg, the survival rate of the saltwater shrimp A will be less than 60% due to incomplete molting or the like, and it will be impossible to reliably improve the production efficiency of the saltwater shrimp A. Therefore, the rearing water 110 should contain 35 to 320 mg of Mg as the mass of solute per 1 L of the rearing water. 2+ and 25-250 mg of Ca. 2+ and 8 to 80 mg of K. + and,

[0033] Also, K + Mg relative to the mass of 2+ The ratio of the masses of the first mass ratio, K + Ca relative to the mass of 2+ The mass ratio of Ca is defined as the second mass ratio. 2+ Mg relative to the mass of 2+is defined as a third mass ratio, if the first mass ratio is less than 0.7 or more than 5.0, the second mass ratio is less than 0.5 or more than 5.0, or the third mass ratio is less than 0.7 or more than 1.4, the survival rate of saltwater shrimp A will be less than 60% due to incomplete molting, etc., and it will be impossible to reliably improve the production efficiency of saltwater shrimp A. Therefore, it is preferable that the first mass ratio is 0.7 to 5.0, the second mass ratio is 0.5 to 5.0, and the third mass ratio is 0.7 to 1.4.

[0034] That is, the breeding water 110 contains 35 to 320 mg of Mg as the mass of solute per 1 L of breeding water. 2+ and 25-250 mg of Ca. 2+ and 8 to 80 mg of K. + and a first mass ratio (Mg 2+ mass / K + The second mass ratio (Ca 2+ mass / K + the third mass ratio (Mg 2+ Mass of Ca 2+ It is preferable that the mass of the rearing water 110 is 0.7 to 1.4. In this case, the survival rate of the saltwater shrimp A is 75% or more, and the survival rate of the saltwater shrimp A can be improved. This improves the efficiency of land-based aquaculture of the saltwater shrimp A. The relationship between the rearing water 110 and the survival rate of the saltwater shrimp A will be described in detail later.

[0035] Furthermore, it is preferable that the third mass ratio of the rearing water 110 is 0.7 to 1.3. In this case, the survival rate of the saltwater shrimp A is 78% or more, which can further improve the survival rate of the saltwater shrimp A and further improve the efficiency of land-based culturing of the saltwater shrimp A.

[0036] Furthermore, the rearing water 110 preferably satisfies the combination of a first mass ratio of 0.7 to 4.0 and a second mass ratio of 0.5 to 4.0, more preferably the combination of a first mass ratio of 1.0 to 4.0 and a second mass ratio of 1.0 to 3.0, and even more preferably the combination of a first mass ratio of 1.5 to 4.0 and a second mass ratio of 2.0 to 3.0. In this case, the survival rate of the saltwater shrimp A is 82% or more, which can further improve the survival rate of the saltwater shrimp A and further improve the efficiency of land-based culturing of the saltwater shrimp A.

[0037] The breeding water 110 is SO4 2- If it does not contain any SO4 2- Compared with the case containing SO4, problems with molting of saltwater shrimp A occur and mortality increases. 2- In addition, the breeding water 110 preferably contains SO4 as the mass of solute per 1 L of breeding water. 2- It is preferable that the amount of the compound contained is 70 to 400 mg.

[0038] Generally, in the environment of the rearing water 110 during shrimp cultivation, the mass of solutes per 1 L of rearing water is about 80 to 100 mg of CaCl (Ca 2+ Functions similar to that of MgSO4, and about 250-300 mg of MgSO4 (Mg 2+ Similar function), K2SO4 is about 100 mg (K + It is desirable to maintain an environment with a total alkalinity of 120 mg / L and a pH of about 7.8. 2- It is involved in the osmoregulation of the body fluids of fish and crustaceans (adjusting the salt concentration inside and outside the body fluids), which may play an important role in life processes such as molting, and is an important part of the environmental conditions for living organisms such as fish and crustaceans. Therefore, the rearing water 110 also contains SO4 as an important factor that affects the normal growth and survival of the saltwater shrimp A. 2- It is preferred that the formula (I) is included.

[0039] The mass (concentration) of each of the above ions is adjusted by adding the corresponding salt. 2+In the case of rearing water 110 containing 40 mg / L of magnesium sulfate, the content can be adjusted by adding about 198.30 mg / L of magnesium sulfate. 2+ If the breeding water 110 contains 240 mg / L of magnesium sulfate, this can be adjusted by adding approximately 1,189.80 mg / L of magnesium sulfate.

[0040] In addition, Ca 2+ In the case of rearing water 110 containing 30 mg / L of calcium chloride, the content can be adjusted by adding about 83.08 mg / L of calcium chloride. 2+ If the breeding water 110 contains 200 mg / L of calcium chloride, this can be adjusted by adding approximately 553.86 mg / L of calcium chloride.

[0041] Also, K + In the case of rearing water 110 containing 10 mg / L of potassium sulfate, the content can be adjusted by adding about 22.28 mg / L of potassium sulfate. + If the breeding water 110 contains 60 mg / L of potassium sulfate, this can be adjusted by adding approximately 133.68 mg / L of potassium sulfate.

[0042] The amounts of salt added above are theoretical values ​​calculated assuming a water temperature of 28°C and a pH of 7.5, but in reality, the ions in the breeding water 110 are not always completely ionized, so the actual amount of salt needed to be added may vary from the theoretical value. Also, please note that the amount of salt needed to be added may vary depending on various factors, including the solubility of each salt, the pH of the water, the temperature of the water, and the influence of other dissolved substances.

[0043] The breeding water 110 is monitored, for example, via a water quality monitoring device 54, for a barometer of the water quality required for breeding the saltwater shrimp A. The breeding water 110 is controlled, for example, via a temperature control device 55, to a water temperature at which the saltwater shrimp A can survive.

[0044] <Salt concentration reduction unit 12> The salinity reduction unit 12 reduces the salinity of the breeding water 110 housed together with the shrimp in the housing unit 11. The salinity reduction unit 12 may reduce the salinity of the breeding water 110 in the housing unit 11 continuously or intermittently.

[0045] The salt concentration reducing unit 12 reduces the salt concentration of the rearing water 111 by 0.10 to 0.50 mass % per day. If the salt concentration of the rearing water 111 is reduced by more than 0.50 mass % per day, the survival rate of the saltwater shrimp A will be 0%, making it impossible to improve the efficiency of land-based aquaculture and promote the growth of the saltwater shrimp A. If the salt concentration of the rearing water 111 is reduced by less than 0.10 mass % per day, the period for acclimating the saltwater shrimp A to the low salinity cannot be completed during the larval stage of the saltwater shrimp A (approximately one month after the start of rearing), making it impossible to improve the efficiency of land-based aquaculture and promote the growth of the saltwater shrimp A.

[0046] For this reason, it is preferable that the salinity concentration reducing unit 12 reduces the salinity of the rearing water 111 by 0.10 to 0.50 mass % per day. In this case, the saltwater shrimp A can be efficiently acclimatized to a low-salinity environment. This can improve the efficiency of land-based aquaculture of the saltwater shrimp A. Furthermore, the weight of the saltwater shrimp A can be efficiently increased. This can reliably promote the growth of the saltwater shrimp A even in an environment with a lower salinity than seawater. The effects of the present invention on the acclimatization efficiency and growth promotion of the saltwater shrimp A will be explained in the examples below.

[0047] The salt concentration reducing section 12 has, for example, a water supply tank 13 and a wastewater tank 14 .

[0048] The water supply tank 13 stores dilution water 130 having a salinity lower than the salinity at which marine organisms can survive, for example. The water supply tank 13 supplies the dilution water 130 to the storage unit 11 via, for example, a water supply pipe 32. The dilution water 130 may be, for example, groundwater or dechlorinated tap water.

[0049] The wastewater tank 14 stores, for example, a portion of the breeding water 110 discharged from the housing unit 11 as wastewater 140. The wastewater tank 14 receives the wastewater 140 discharged from the housing unit 11 via a drainage pipe 33, for example.

[0050] <Saltwater Shrimp A> Saltwater shrimp A refers to shrimp that fall under marine organisms and does not include shrimp that fall under freshwater organisms. Saltwater shrimp A is, for example, edible shrimp. As saltwater shrimp A, particularly juvenile shrimp are used in order to efficiently acclimate them to the rearing water 110, which has a lower salt concentration than seawater. Specific examples of saltwater shrimp A include Penaeidae (penguin shrimp, whiteleg shrimp, banana shrimp, etc.), Prionidae (cherry shrimp, etc.), Palaemonidae (king shrimp, botan shrimp, Pandalus prawn, etc.), Spinylodonidae (spiny lobster, etc.), etc.

[0051] The saltwater shrimp A are automatically fed with food, for example, via an automatic feeding device 56.

[0052] <Filtering Device 51> The filtering device 51 filters the water supplied to the storage unit 11. The filtering device 51 may be provided outside the storage unit 11 or may be provided inside the storage unit 11.

[0053] The filtration device 51 filters, for example, the circulating water supplied to the storage unit 11 via the circulation piping 31 or the dilution water 130 supplied to the storage unit 11 via the water supply piping 32. In this case, the filtration device 51 may be provided inside the circulation piping 31 or the water supply piping 32.

[0054] The filter device 51 includes, for example, a known filter medium, specifically a sponge for physical filtration, a porous filter medium with bacteria for biological filtration, activated carbon for chemical filtration, or the like.

[0055] <Disinfection Device 52> The disinfection device 52 disinfects the water supplied to the storage unit 11. The disinfection device 52 may be provided outside the storage unit 11 or may be provided inside the storage unit 11.

[0056] The disinfection device 52 disinfects, for example, the circulating water supplied to the storage unit 11 via the circulation pipe 31 or the dilution water 130 supplied to the storage unit 11 via the water supply pipe 32. In this case, the disinfection device 52 may be provided in the circulation pipe 31 or the water supply pipe 32.

[0057] The disinfection device 52 may be, for example, a known ultraviolet sterilization and purification device, an ozone generator, or a hypochlorous acid water generator.

[0058] <Bubble Generator 53> The bubble generator 53 generates oxygen nanobubble water or the like (including oxygen nanobubble water and / or oxygen microbubble water) by blowing gas containing at least oxygen into the water supplied to the storage unit 11. The bubble generator 53 may be provided outside the storage unit 11 or may be provided inside the storage unit 11.

[0059] The bubble generator 53 generates oxygen nanobubble water or the like by blowing a gas containing at least oxygen into, for example, the circulating water supplied to the storage unit 11 via the circulation pipe 31 or the dilution water 130 supplied to the storage unit 11 via the water supply pipe 32. In this case, the bubble generator 53 may be provided in the circulation pipe 31 or the water supply pipe 32.

[0060] The method for generating oxygen nanobubble water or the like using the bubble generator 53 involves pressurizing a gas such as oxygen or air, dissolving it in water supplied to the container 11 in a supersaturated state, and then rapidly reducing the pressure to generate nanobubbles or the like (including nanobubbles and microbubbles) in the liquid. Oxygen nanobubble water refers to water containing fine oxygen gas bubbles with a nanometer-order diameter (1 μm or less). However, in addition to the nanometer-order fine oxygen gas bubbles, fine oxygen gas bubbles with a micrometer-order diameter (1 to 100 μm) may also be contained. Alternatively, the microbubbles may be floated and separated, leaving only the nanobubbles in the liquid. The bubble generator 53 may also generate oxygen nanobubble water or the like containing oxygen as at least nanometer-sized fine bubbles, including either oxygen nanobubbles or air nanobubbles, or both. A specific example of oxygen nanobubble water is water containing approximately 90% of bubbles with a diameter of 200 nm or less, with an average diameter of 50 nm to 100 nm, and a bubble concentration of 2×10 8 Pieces / L~6×10 9 pcs / L.

[0061] Examples of details of the bubble generator 53 include a "swirl flow method" in which oxygen bubbles are created by mixing oxygen gas with water and swirling it at high speed, a "pressure dissolution method" in which oxygen bubbles are created by applying pressure to oxygen gas, dissolving it in water, and then releasing it all at once, a "micropore method" in which oxygen bubbles are created by applying pressure to oxygen gas and passing it through micropores such as orifices, an "ultrasonic method" in which cavitation is used to cause the oxygen gas in water to expand and create oxygen bubbles, a "static mixer method" in which bubbles are created by swirling and crushing gas in a gas-liquid flow path equipped with protrusions, and an "ejector method" or "venturi method" in which bubbles are created by creating a sudden pressure change in the gas-liquid flow path. However, the method for generating oxygen nanobubble water, etc. is not particularly limited, and any method can be used as long as it can generate nanobubble water, etc. containing fine oxygen gas on the nano- or micro-order.

[0062] By turning oxygen into fine nanobubble-like bubbles, the T1 relaxation time (the time from when the water movement (nuclear spin) becomes active due to nuclear magnetization until it returns to a quiet state) is improved compared to ordinary distilled water, i.e., the motility is increased, and the mobility of the substances contained in the storage unit 11 is improved. This makes it easier for the oxygen nanobubble water, the fed food, the saltwater shrimp A, etc. to come into contact with each other within the storage unit 11, and the growth of the saltwater shrimp A can be further promoted.

[0063] The acclimation system 1 uses the above-described air bubble generator 53. In this case, the weight of the saltwater shrimp A can be increased efficiently. This ensures that the growth of the saltwater shrimp A can be promoted even in an environment with a lower salinity than seawater. The effects of the present invention on the acclimation efficiency and growth promotion of the saltwater shrimp A will be described in the examples below.

[0064] <Water Quality Monitoring Device 54> The water quality monitoring device 54 monitors the barometer of the water quality of the breeding water 110. The water quality monitoring device 54 monitors, for example, the dissolved oxygen concentration (mg / L), pH (Potential Hydrogen), NH4 + Concentration (mg / L), NO2 - Concentration (mg / L), NO3 -The manager of the acclimation system 1 refers to the monitoring results of the water quality monitor 54 and, if necessary, supplies a pH adjuster such as lime water to the housing unit 11 to adjust the water quality of the rearing water 110.

[0065] As the water quality monitoring device 54, for example, a known automatic water quality monitoring device may be used.

[0066] <Temperature Control Device 55> The temperature control device 55 controls the water temperature of the breeding water 110. As the temperature control device 55, for example, a known heater with a built-in thermostat may be used.

[0067] <Automatic Feeder 56> The automatic feeder 56 automatically supplies food to the saltwater shrimp A in the breeding water 110. As the automatic feeder 56, a known automatic fish feeder may be used.

[0068] <Illumination Unit 57> The illumination unit 57 irradiates the rearing water 110 with green light L. The illumination unit 57 continuously irradiates the rearing water 110 with green light L throughout the rearing period of the saltwater shrimp A. In this case, the saltwater shrimp A can efficiently increase their weight. This ensures that the growth of the saltwater shrimp A can be promoted even in an environment with a lower salinity than seawater. The effects of the present invention on the acclimation efficiency and growth promotion of the saltwater shrimp A will be described in the examples below.

[0069] According to "New Technology: Growth Promotion of Spotted Flounder and Flatfish by Irradiating Green Light, by Takahashi Akiyoshi, Shimizu Daisuke, Tsuru Kumiko, Kiyabu Hitoshi, and Mizusawa Kanta, Monthly Aquanet, April 2019 issue / separate print," it has been proven that irradiation with specific colors increases the weight of flatfish in general and is effective in promoting efficient growth. In terms of the relationship between color and growth promotion effect, it was confirmed that green, blue-green, and blue are most effective in increasing weight in that order. In more detail, flatfish seedlings (average weight 20.6g) were stocked in three square concrete land tanks (4.5m x 4.5m, water depth approximately 30cm) with 600 fish in each tank (stocking density 30 fish / m 2The weight changes over a period of approximately one year were measured for a control group, where fish were housed in a greenhouse (household) and reared under natural light and natural photoperiod, and a group exposed to 12 hours of green LED light from Stanley Electric Co., Ltd. (registered trademark) from 6:00 to 18:00. The average weight of the exposed group (776.1±26.2 g) was 61% higher than that of the control group (481.6±18.9 g). Thus, it was confirmed that green light irradiation using an LED as a light source can promote the growth of flounder even in aquariums used in aquaculture farms. Similar lighting equipment and illumination conditions may also be used for the acclimation system 1 of the present invention.

[0070] <Artificial aquatic plants 6> The artificial aquatic plants 6 are provided in advance in the storage section 11. The artificial aquatic plants 6 can prevent the saltwater shrimp A from swimming together in the storage section 11 and cannibalism, thereby suppressing a decrease in the survival rate of the saltwater shrimp A. As the artificial aquatic plants 6, for example, artificial spawning algae such as Kinran (registered trademark) (made of vinylon) manufactured by Kyorin Corporation can be used.

[0071] The acclimation system 1 of the present invention uses the above-mentioned artificial aquatic plants 6. In this case, the weight of the saltwater shrimp A can be increased efficiently. This ensures that the growth of the saltwater shrimp A can be promoted even in an environment with a lower salinity than seawater. The effects of the present invention on the acclimation efficiency and growth promotion of the saltwater shrimp A will be explained in the examples below.

[0072] Next, as a method for acclimatizing saltwater shrimp in this embodiment, an example of the operation of the acclimatization system 1 will be described. In this embodiment, the operation of the acclimatization system 1 will be described based on operations by an administrator of the acclimatization system 1. However, if the acclimatization system 1 includes a processing device such as a known personal computer (PC) (not shown), the operation of each component of the acclimatization system 1 may be realized by processing based on a pre-stored program.

[0073] The operation of the acclimation system 1 includes, for example, a salt concentration reduction step S11 as shown in FIG.

[0074] 3( a), for example, the manager stores rearing water 111 having a salinity equivalent to that of seawater in which marine organisms can survive, and saltwater shrimp A in the storage unit 11. As the rearing water 111, natural seawater or artificial seawater having a salinity close to that of the environment in which saltwater shrimp A naturally inhabits is used.

[0075] The manager also connects the salinity reduction unit 12 to the storage unit 11 that stores the breeding water 111. More specifically, the manager connects the water supply tank 13 to the storage unit 11 via a water supply pipe 32 and the wastewater tank 14 via a drainage pipe 33.

[0076] In addition, when using the lighting unit 57 and artificial aquatic plants 6, the manager confirms that the lighting unit 57 is capable of irradiating green light L onto the breeding water 110 and that the artificial aquatic plants 6 are placed in the breeding water 110.

[0077] <Salinity Concentration Reduction Step S11> In the salinity concentration reduction step S11, the salinity concentration reduction unit 12 reduces the salinity of the rearing water 111 in the storage unit 11 by supplying dilution water 130 and discharging wastewater 140, for example, as shown in FIG. 3( b). More specifically, the salinity reduction unit 12 supplies dilution water 130 to the storage unit 11 from, for example, the water supply tank 13, and discharges the rearing water 111 from the storage unit 11 to the wastewater tank 14. As a result, a portion of the rearing water 111 in the storage unit 11 is replaced with the dilution water 130, resulting in rearing water 112 having a lower salt concentration than the rearing water 111. By repeatedly reducing the salt concentration of the rearing water 111 or rearing water 112 in the storage unit 11 by the salinity reduction unit 12 for a predetermined period, the rearing water 111 or rearing water 112 in the storage unit 11 becomes rearing water 110 having a salt concentration of, for example, approximately 0.007 to 0.500% by mass.

[0078] Here, the breeding water 112 refers to water having a salinity between the salinity of the breeding water 111 and the salinity of the dilution water 130. In other words, the salinity of the breeding water 112 is lower than the salinity of the breeding water 111 and higher than or equal to the salinity of the breeding water 110.

[0079] The salinity reduction unit 12 may reduce the salinity of the rearing water 111 (112) by adjusting the flow rates of the dilution water 130 supplied to the storage unit 11 and the discharge of the wastewater 140 from the storage unit 11 to be approximately the same, or may reduce the salinity of the rearing water 111 (112) by adjusting them to different flow rates. The salinity reduction unit 12 may also reduce the salinity of the rearing water 111 (112) by only supplying the dilution water 130 without discharging the wastewater 140.

[0080] In the salt concentration reduction step S11, the salt concentration reduction unit 12 reduces the salt concentration of the rearing water 111 by 0.10 to 0.50 mass% per day. If the salt concentration of the rearing water 111 is reduced by more than 0.50 mass% per day, the survival rate of the saltwater shrimp A will be 0%, making it impossible to improve the efficiency of land-based aquaculture and promote its growth. Furthermore, if the salt concentration of the rearing water 111 is reduced by less than 0.10 mass% per day, the period for acclimating the saltwater shrimp A to a low salinity will not be completed by the time the saltwater shrimp A reaches the larval stage, making it impossible to improve the efficiency of land-based aquaculture and promote its growth. Therefore, it is preferable that the salt concentration reduction unit 12 reduce the salt concentration of the rearing water 111 by 0.10 to 0.50 mass% per day. In this case, the saltwater shrimp A can be efficiently acclimated to a low-salinity environment. This improves the efficiency of land-based culture of the saltwater shrimp A. It also enables the saltwater shrimp A to efficiently increase in weight. This ensures the growth of the saltwater shrimp A even in an environment with a lower salinity than seawater.

[0081] In addition, before and after the salt concentration reduction step S11, the rearing water 111 before the reduction of the salt concentration, the rearing water 112 during the reduction of the salt concentration, and the rearing water 110 after the reduction of the salt concentration all have a solute mass of 35 to 320 mg Mg per 1 L of rearing water. 2+ and 25-250 mg of Ca. 2+ and 8 to 80 mg of K. + and a first mass ratio (Mg 2+ mass / K + The second mass ratio (Ca 2+ mass / K +the third mass ratio (Mg 2+ Mass of Ca 2+ It is preferable that the mass of the saltwater shrimp A is 0.7 to 1.4. In this case, the survival rate of the saltwater shrimp A becomes 75% or more, and the survival rate of the saltwater shrimp A can be improved. This makes it possible to improve the efficiency of land-based culture of the saltwater shrimp A. The relationship between the rearing water 110 (rearing water 111) and the survival rate of the saltwater shrimp A will be described in detail later.

[0082] Furthermore, in the salinity concentration reduction step S11, the bubble generator 53 may blow gas containing at least oxygen into the water supplied to the storage unit 11 via, for example, the circulation pipe 31 or the water supply pipe 32. At this time, oxygen nanobubbles and the like are generated in the rearing water 110 (rearing water 111, rearing water 112). As a result, oxygen nanobubble water and the like can be generated from the rearing water 110. Note that a step of generating oxygen nanobubble water, which is distinct from the salinity concentration reduction step S11, may be performed at least either before or after the salinity concentration reduction step S11, or may be performed multiple times.

[0083] The above-described steps are performed, and the operation of the habituation system 1 in this embodiment is completed. Note that the habituation system 1 may, for example, repeatedly perform the above-described steps.

[0084] According to this embodiment, the method includes a salinity reduction step S11 in which the salinity of the rearing water 111 in which the saltwater shrimp A is reared is reduced by 0.10 to 0.50 mass % per day. This allows the saltwater shrimp A to be efficiently acclimatized to a low-salinity environment. This improves the efficiency of land-based aquaculture of the saltwater shrimp A. Furthermore, the weight of the saltwater shrimp A can be increased more efficiently than in seawater. This reliably promotes the growth of the saltwater shrimp A.

[0085] Furthermore, according to this embodiment, the salinity concentration reducing step S11 generates oxygen microbubble water or oxygen nanobubble water by blowing a gas containing at least oxygen into the rearing water 110 (the rearing water 111 and the rearing water 112). This allows the saltwater shrimp A to efficiently increase their weight. This ensures that the saltwater shrimp A can further promote their growth.

[0086] Furthermore, according to this embodiment, the salt concentration reducing step S11 reduces the salt concentration of the rearing water 111 while irradiating it with green light L. This allows the saltwater shrimp to efficiently increase their body weight, thereby ensuring further growth promotion of the saltwater shrimp.

[0087] Furthermore, according to this embodiment, the salt concentration reducing step S11 reduces the salt concentration of the rearing water 111 in the housing section 11 in which the artificial aquatic plants 6 have been placed in advance. This improves the survival rate of the saltwater shrimp A. This further improves the efficiency of land-based culturing of the saltwater shrimp A.

[0088] Furthermore, according to this embodiment, the salt concentration reducing unit 12 is provided, which reduces the salt concentration of the rearing water 111 housed in the housing unit 11 together with the saltwater shrimp A by 0.10 to 0.50 mass % per day. This allows the saltwater shrimp A to be efficiently acclimatized to a low-salinity environment. This improves the efficiency of land-based farming of the saltwater shrimp A. Furthermore, the weight of the saltwater shrimp A can be increased more efficiently than in seawater. This reliably promotes the growth of the saltwater shrimp A.

[0089] Furthermore, according to this embodiment, the breeding water 110 (breeding water 111) has a Mg concentration of 35 to 320 mg before and after the salt concentration reduction step S11. 2+ and 25-250 mg of Ca. 2+ and 8 to 80 mg of K. + The first mass ratio is 0.7 to 5.0, the second mass ratio is 0.5 to 5.0, and the third mass ratio is 0.7 to 1.4. This allows the survival rate of saltwater shrimp to be 75% or more. This further improves the efficiency of land-based aquaculture of saltwater shrimp A.

[0090] (Cultivation method using aquaponics 2) An example of a cultivation method using aquaponics 2 using saltwater shrimp A acclimatized by the shrimp acclimation method of this embodiment will be described with reference to Figures 4 and 5. Note that a description of the same configuration as the shrimp acclimation method described above will be omitted. First, the aquaponics 2 used in the cultivation method using aquaponics 2 of this embodiment will be described.

[0091] 4, the aquaponics 2 includes the acclimation system 1 described above, a hydroponic cultivation tank 21 that accommodates the plant B, a decomposition solution generator 22, and a decomposition solution supplier 23. In this embodiment, an example of a closed circulation type aquaponics 2 in which the breeding water 110 in the accommodation unit 11 in the hydroponic cultivation tank 21 is described, but a flow-through type in which the breeding water 110 in the accommodation unit 11 is used in the hydroponic cultivation tank 21 and then discarded as wastewater may also be used.

[0092] <Storage unit 11> The storage unit 11 is connected to the hydroponic cultivation tank 21, for example, via a first circulation pipe 31a and a second circulation pipe 31b. The storage unit 11 supplies rearing water 110 to the hydroponic cultivation tank 21, for example, via the first circulation pipe 31a. The storage unit 11 may be supplied with wastewater discharged from the hydroponic cultivation tank 21, for example, via the second circulation pipe 31b. For example, water supply pipes of the same quality as the circulation pipe 31 may be used as the first circulation pipe 31a and the second circulation pipe 31b.

[0093] <Hydroponic cultivation tank 21> The hydroponic cultivation tank 21 accommodates a plant B. The hydroponic cultivation tank 21 is supplied with rearing water 110 containing excrement of the saltwater shrimp A from the accommodation unit 11 via a first circulation pipe 31a. The hydroponic cultivation tank 21 supplies rearing water and the like (including the rearing water 210 and the decomposition liquid 220 described below) in the hydroponic cultivation tank 21 to the accommodation unit 11 via a second circulation pipe 31b.

[0094] The hydroponic cultivation tank 21 may be supplied with the rearing water 110 containing excrement from the saltwater shrimp A, as well as the rearing water 110 not containing excrement from the saltwater shrimp A. Here, the rearing water 110 supplied to the hydroponic cultivation tank 21 is referred to as the rearing water 210. The rearing water 210 has the same quality as the rearing water 110, for example.

[0095] 4, the decomposition liquid producing unit 22 biodegrades excrement of the saltwater shrimp A to produce a decomposition liquid 220. The decomposition liquid producing unit 22 is provided in the hydroponic cultivation tank 21, for example.

[0096] The decomposition liquid generator 22 is, for example, a carrier for immobilizing microorganisms, and generates a decomposition liquid 220 by biodegrading the excrement of the saltwater shrimp A contained in the breeding water 210 in the hydroponic cultivation tank 21 through the decomposition action of the microorganisms (not shown). Examples of the microorganisms immobilized in the decomposition liquid generator 22 include nitrifying bacteria. The decomposition liquid generator 22 may be provided in the storage unit 11, for example.

[0097] <Decomposition Solution Supply Unit 23> The decomposition solution supply unit 23 supplies the decomposition solution 220 to, for example, the plant B. The decomposition solution supply unit 23 is provided, for example, in the hydroponic cultivation tank 21. In this case, the weight of the saltwater shrimp A and the weight of the plant B can be efficiently increased. This ensures that the growth of the saltwater shrimp A can be promoted simultaneously with that of the plant B, which is susceptible to salt damage. The effect of the present invention on the growth promotion of the plant B will be described in the examples below.

[0098] The decomposition liquid supply unit 23 is, for example, a base such as a sponge that fixes the plant B in the hydroponic cultivation tank 21. The decomposition liquid supply unit 23 supplies at least one of the rearing water 210 and the decomposition liquid 220 to the plant B. When a porous material such as a sponge is used for the decomposition liquid supply unit 23, the material may also function as the decomposition liquid production unit 22 by carrying microorganisms such as nitrifying bacteria.

[0099] <Plant B> Plant B is housed in the hydroponic cultivation tank 21. Plant B is fixed in the hydroponic cultivation tank 21 by a decomposing solution supply unit 23 configured with a base such as a sponge. For example, a plant that can be adapted to hydroponic cultivation using breeding water 110 whose salt concentration has been reduced by the salt concentration reducing unit 12 is selected as the plant B. Therefore, although halophytes such as ice plants have conventionally been cultivated in aquaponics using marine organisms such as saltwater shrimp A, according to the present invention, plants B other than halophytes such as ice plants can also be cultivated.

[0100] Examples of plant B include Asteraceae plants (leaf lettuce, etc.), Amaranthaceae plants (spinach, Swiss chard, etc.), Amaryllidaceae plants (chili chives, etc.), Apiaceae plants (parsley, etc.), Brassicaceae plants (watercress, wasabi greens, etc.), Lamiaceae (sweet basil, etc.), Solanaceae (chili peppers, paprika, bell peppers, etc.), and Alliaceae (green onions, etc.).

[0101] Next, an example of the operation of the aquaponics 2 will be described as a cultivation method using the aquaponics 2 in this embodiment. The aquaponics 2 operates each component based on, for example, an administrator's operation or a pre-stored program. The operation of the aquaponics 2 includes, for example, a salt concentration reduction step S11, a decomposition solution generation step S21, and a decomposition solution supply step S22, as shown in FIG. 5 . In the operation of the aquaponics 2, the salt concentration reduction step S11 may be omitted if it is performed by another acclimation system 1′ independent of the acclimation system 1 constituting the aquaponics 2.

[0102] Before the decomposition liquid production process S21, the aquaponics 2 drains the breeding water 110 containing the excrement of the saltwater shrimp A from the storage section 11, as shown in Figure 4, and supplies the breeding water 210 of the same quality as the breeding water 110 to the hydroponic cultivation tank 21.

[0103] <Decomposition Liquid Producing Step S21> In the decomposition liquid producing step S21, the decomposition liquid producing unit 22 biodegrades the excrement of the saltwater shrimp A in the breeding water 210 to produce the decomposition liquid 220.

[0104] <Decomposition Solution Supplying Step S22> In the decomposition solution supplying step S22, the decomposition solution supplying unit 23 supplies the decomposition solution 220 produced in the decomposition solution producing step S21, for example, to the plant B. In this case, it is possible to efficiently increase the weight of the saltwater shrimp A and the weight of the plant B. This makes it possible to reliably promote the growth of the saltwater shrimp A and the plant B, which are susceptible to salt damage, at the same time.

[0105] This embodiment includes a salt concentration reduction step S11 for reducing the salt concentration of the breeding water 111 in which the saltwater shrimp A is reared by 0.10 to 0.50 mass % per day, a decomposition solution production step S21 for biodegrading excrement of the saltwater shrimp A to produce a decomposition solution 220, and a decomposition solution supply step S22 for supplying the produced decomposition solution 220 to the plant B hydroponically cultivated in the breeding water 110 with the reduced salt concentration. This makes it possible to efficiently increase the weight of the saltwater shrimp A and the weight of the plant B. This ensures that the growth of the saltwater shrimp A can be reliably promoted simultaneously with that of the plant B that is susceptible to salt damage or that can grow in freshwater.

[0106] Furthermore, this embodiment includes a salinity reduction unit 12 that reduces the salt concentration of the breeding water 111 contained in the housing unit 11 together with the saltwater shrimp A by 0.1 to 0.5 mass % per day, a decomposition solution production unit 22 that biodegrades excrement from the saltwater shrimp A to produce a decomposition solution 220, and a decomposition solution supply unit 23 that supplies the produced decomposition solution 220 to the plant B that is hydroponically cultivated in the breeding water 110 with the reduced salt concentration. This makes it possible to efficiently increase the weight of the saltwater shrimp A and the weight of the plant B. This ensures that the growth of the saltwater shrimp A can be reliably promoted simultaneously with that of the plant B that is susceptible to salt damage or that can grow in freshwater.

[0107] The following will specifically explain the present invention and comparative examples using the above-described embodiment.

[0108] <Experiment 1: Acclimation efficiency of saltwater shrimp A for each reduction in the salinity of rearing water> In this experiment, the acclimation efficiency of saltwater shrimp A was confirmed by comparing the survival rate of saltwater shrimp A during the period of reduced salinity for each reduction in the salinity of the rearing water in which saltwater shrimp A was reared. In addition, after the reduction in salinity, the body length and weight gain of saltwater shrimp A on day 90 from the start of rearing were calculated, and the growth promotion effect of saltwater shrimp A was confirmed, particularly based on the weight gain. In this experiment, green artificial aquatic plants were placed in the rearing water as artificial aquatic plants 6.

[0109] In this experiment, whiteleg shrimp were used as saltwater shrimp A. Specifically, juvenile shrimp less than one month after hatching, with an average body length of approximately 0.8 cm and an average body weight of approximately 0.2 g were used. The number of whiteleg shrimp used in each experiment was 2,000 per condition (per test group). A 2,000 L tank capable of accommodating 2,000 whiteleg shrimp was used as the storage unit 11.

[0110] In this experiment, the average body length of the whiteleg shrimp was measured by measuring the length from the snout to the tail of each individual whiteleg shrimp with a ruler, and dividing the total body length of each individual by the number of individuals. The average body weight of the whiteleg shrimp was measured by measuring the total weight of the whiteleg shrimp, the housing 11, and the rearing water 110, and the weight of the housing 11 and the rearing water 110 with an electronic balance (TX423N), subtracting the weight of the housing 11 and the rearing water 110 from the total weight, and dividing the difference by the number of individuals in the housing 11.

[0111] The salinity was measured by immersing the sensor of a salinity meter "7IN1 Water Quality Tester" manufactured by Wanbang EP Tech, which has a salinity measurement range of 0 to 25% and can measure in 0.001% increments, into the breeding water 110 in the housing unit 11. The amount of dissolved oxygen was measured using a dissolved oxygen meter "AR8406." The pH was measured using a pH meter manufactured by DKK-TOA Corporation (registered trademark).

[0112] Saltwater shrimp A was fed using an automatic feeder "EV500" manufactured by EVNICE fish feeder. For juvenile saltwater shrimp A with a body length of 6 cm or less, feed with a protein content of about 38% by mass or more was fed. Similarly, saltwater shrimp A with a body length of more than 6 cm but less than 10 cm was fed with feed with a protein content of about 36-38% by mass, and saltwater shrimp A with a body length of 10 cm or more was fed with feed with a protein content of about 32-36% by mass. Furthermore, since the salinity reduction period in this experiment lasted for one month from the start of cultivation, which corresponds to the juvenile stage of saltwater shrimp A, the appropriate amount of feed for juvenile shrimp was 5% of saltwater shrimp A's body weight per day, fed in nine or more divided portions per day.

[0113] The rearing environment for saltwater shrimp A was set at a rearing density of 5 kg / m 3 The water temperature of the breeding water 110 is 28 to 32°C, the amount of dissolved oxygen in the breeding water 110 is 6.5 to 10.0 mg / L, the pH of the breeding water 110 is 6.8 to 8.2, and the NH4 + The concentration is 0.0 to 0.5 (mg / L), and the NO2 - The concentration is 0.0 to 0.5 (mg / L), and the NO3 - The salt concentration was adjusted to 100 mg / L or less. Additionally, the rearing water 110 was circulated at 40 L / min using a water pump manufactured by Eheim GmbH & Co. KG, and air was blown using an air pump "AP-100F." The temperature inside the housing unit 11 was controlled using an aquarium cooler "ZR-250" as the temperature control device 55. The rearing water 111 before the salinity reduction was adjusted to the same levels as the rearing water 110 in terms of rearing density, water temperature, dissolved oxygen content, pH, and each ion concentration.

[0114] The main components of the breeding water 110 were adjusted to 40 mg / L to 240 mg / L of magnesium ions, 30 mg / L to 200 mg / L of calcium ions, 10 mg / L to 60 mg / L of potassium ions, approximately 70 mg / L to 400 mg / L of sulfate ions, and approximately 8 mg / L of strontium ions. The breeding water 111 before reduction in salinity was adjusted to the same levels as the breeding water 110. The breeding water 111 was prepared by using artificial seawater with a salinity of approximately 3.2% as the breeding water, and the salinity was reduced to approximately 0.007% to 0.500% to prepare the breeding water 110. The method for reducing the salinity of the rearing water 111 was to drain a portion of the rearing water 111 in the storage unit 11 and supply an approximately equal amount of groundwater (fresh water) to reduce the salinity of the rearing water 111 in the storage unit 11. The operation of draining the rearing water 111 and supplying groundwater was an intermittent operation in which the rearing water 111 was continuously supplied and drained for, for example, approximately 30 minutes per hour.

[0115] The daily reductions in salt concentration in the rearing water 111 compared in this experiment were "less than 0.10% by mass" (Comparative Example 1), "0.10% by mass" (Invention Example 1), "0.20% by mass" (Invention Example 2), "0.25% by mass" (Invention Example 3), "0.35% by mass" (Invention Example 4), "0.40% by mass" (Invention Example 5), "0.50% by mass" (Invention Example 6), "1.00% by mass" (Comparative Example 2), "1.50% by mass" (Comparative Example 3), and "2.00% by mass" (Comparative Example 4). Among these, the daily reductions in salt concentration of 0.10 to 0.50% by mass according to the present invention were designated Inventive Examples 1 to 6, respectively. Furthermore, the example in which the daily reduction in salt concentration was less than 0.10% by mass was designated Comparative Example 1, and the examples in which the daily reductions in salt concentration were 1.00%, 1.50%, and 2.00% by mass were designated Comparative Examples 2 to 4, respectively.

[0116] The final salinity of the rearing water 110 was set to a low-salinity environment (including a completely freshwater environment and an environment close to freshwater) of 0.007 to 0.010% by mass, and the daily reduction in salinity was reduced as necessary to adjust for fractional changes to this salinity. For example, for the condition of a daily reduction in salinity of "0.35% by mass," a maximum reduction in salinity of 0.35% by mass / day was set, and an adjustment of 0.05 to 0.15% by mass / day was added to adjust for fractional changes.

[0117] The results of this experiment are shown in Table 1.

[0118]

[0119] According to Table 1, the survival rates of vannamei shrimp in each example were 78% for Inventive Example 1, 99% for Inventive Example 2, 95% for Inventive Example 3, 95% for Inventive Example 4, 60% for Inventive Example 5, 21% for Inventive Example 6, and 0% for Comparative Examples 2 to 4. Note that the survival rate of Comparative Example 1 could not be measured because the salt concentration reduction period could not be completed within the larval shrimp period.

[0120] According to Table 1, the weight gain of the vannamei shrimps in each Example was 20.3 g / head for Inventive Example 1, 25.4 g / head for Inventive Example 2, 22.8 g / head for Inventive Example 3, 22.8 g / head for Inventive Example 4, 19.1 g / head for Inventive Example 5, and 19.1 g / head for Inventive Example 6. The body length gain of the vannamei shrimps in each Example was 12.7 cm / head for Inventive Example 1, 15.2 cm / head for Inventive Example 2, 13.7 cm / head for Inventive Example 3, 13.7 cm / head for Inventive Example 4, 12.1 cm / head for Inventive Example 5, and 12.1 cm / head for Inventive Example 6. Note that the survival rates of Comparative Examples 2 to 4 were not measurable because they reached 0% before the 90th day.

[0121] In Examples 1 to 6 of the present invention, the daily reduction in the salt concentration of the rearing water 111 was set to 0.10 to 0.50% by mass. As a result, some vannamei shrimp were able to be acclimatized to survive in a low-salinity environment. This allows saltwater shrimp A to be acclimatized efficiently to a low-salinity environment. This improves the efficiency of land-based aquaculture of saltwater shrimp A. In particular, it was confirmed that acclimation to a low-salinity environment was possible with a high survival rate, with a survival rate of 60% or more when the salt concentration was reduced by 0.10 to 0.40% by mass (Examples 1 to 5 of the present invention) and a survival rate of 90% or more when the salt concentration was reduced by 0.20 to 0.35% by mass (Examples 2 to 4 of the present invention).

[0122] Furthermore, according to Table 1, in Examples 1 to 6 of the present invention, the weight gain of the vannamei shrimp on the 90th day of rearing was 19.1 to 25.4 g / head, and the body length gain was 12.1 to 15.2 cm / head. This was confirmed to be higher than the weight gain of 17.8 g / head and the body length gain of 11.2 cm / head on the 90th day after the start of rearing in artificial seawater with a salinity of 3.20% by mass, which is a seawater environment (Comparative Example 5 in Table 2). Therefore, the weight of saltwater shrimp A can be increased more efficiently than in seawater. The body length gain also showed a similar tendency. This ensures the growth of saltwater shrimp A.

[0123] In Comparative Example 1, the amount of reduction in the salt concentration of the rearing water 111 per day was set to less than 0.10% by mass, but the period of reduction in salt concentration could not be completed by the time the vannamei shrimp reached the larval shrimp stage, and therefore the saltwater shrimp A could not be efficiently acclimatized to a low-salinity environment.

[0124] In Comparative Examples 2 to 4, the amount of reduction in the salt concentration of the rearing water 111 per day was set to 1.00 to 2.00% by mass, but the vannamei shrimp died out before they could become acclimatized to the low-salinity environment. Therefore, it was not possible to efficiently acclimate the saltwater shrimp A to the low-salinity environment.

[0125] That is, the amount of reduction in the salt concentration of the rearing water 111 that is suitable for acclimatizing the saltwater shrimp A to a low-salinity environment is 0.10 to 0.50 mass% / day, more preferably 0.10 to 0.40 mass% / day, and even more preferably 0.20 to 0.35 mass% / day.

[0126] <Experiment 2: Growth-promoting effect of saltwater shrimp A at different salinity concentrations in rearing water> Next, a verification experiment on the growth-promoting effect of saltwater shrimp A at different salinity concentrations in the rearing water 110 according to the present invention will be described. Specifically, the body length and weight gains were calculated from the body length and weight of shrimp reared in a seawater environment over a 90-day rearing period and the body length and weight of saltwater shrimp A acclimated by the acclimation method of Experiment 1 over a 90-day rearing period, and the growth-promoting effect of saltwater shrimp A was confirmed, particularly based on the weight gain. Note that the 90-day rearing period for saltwater shrimp A includes the period of reduced salinity in Experiment 1. The survival rate during the 90-day rearing period was also confirmed.

[0127] In this experiment, a 300 L tank containing 1,000 vannamei shrimp and a 500 L tank containing 1,000 vannamei shrimp were used for one condition (one test plot).

[0128] This experiment was carried out after Experiment 1, i.e., 2 to 3 months after the start of culture, which corresponds to the growth period of saltwater shrimp A. Therefore, as the appropriate feeding amount for shrimp in the growth period, saltwater shrimp A was fed in an amount equivalent to 2% of the body weight per day, divided into 9 or more portions per day.

[0129] The rearing environment for saltwater shrimp A was set at a rearing density of 5 kg / m 3The water temperature of the breeding water 110 is 25 to 28°C, the amount of dissolved oxygen in the breeding water 110 is 6.0 to 8.5 mg / L, the pH of the breeding water 110 is 6.0 to 8.3, and the NH4 + The concentration is 0.0 to 0.5 (mg / L), and the NO2 - The concentration is 0.0 to 0.5 (mg / L), and the NO3 - The concentration was adjusted to 30 to 120 (mg / L). Other experimental conditions were the same as in Experiment 1.

[0130] The salt concentrations of the rearing water 110 compared in this experiment were "0.007% by mass" (Invention Example 7), "0.010% by mass" (Invention Example 8), "0.015% by mass" (Invention Example 9), "0.020% by mass" (Invention Example 10), "0.025% by mass" (Invention Example 11), "0.050% by mass" (Invention Example 12), "0.100% by mass" (Invention Example 13), "0.150% by mass" (Invention Example 14), "0.200% by mass" (Invention Example 15), "0.250% by mass" (Invention Example 16), "0.400% by mass" (Invention Example 17), "0.500% by mass" (Invention Example 18), and "3.20% by mass" (Comparative Example 5). Of these, salt concentrations of 0.007 to 0.50% by mass according to the present invention were designated Inventive Examples 7 to 18, respectively. Furthermore, an example in which the salt concentration was not reduced from 3.200 mass%, i.e., the salt concentration equivalent to seawater, was designated as Comparative Example 5. The amount of reduction in salt concentration per day was adjusted to 0.20 to 0.35 mass%.

[0131] The results of this experiment are shown in Table 2.

[0132]

[0133] According to Table 2, the weight gain of the vannamei shrimp in each Example was 25.4 g / head for Inventive Examples 7 to 16, 23.3 g / head for Inventive Examples 17 and 18, and 17.8 g / head for Comparative Example 5. The body length gain of the vannamei shrimp in each Example was 15.2 cm / head for Inventive Examples 7 to 16, 14.2 cm / head for Inventive Examples 17 and 18, and 11.2 cm / head for Comparative Example 5. The survival rate of the vannamei shrimp in each Example was 90% for Inventive Example 7, 90% for Inventive Example 8, 89% for Inventive Example 9, 87% for Inventive Example 10, 86% for Inventive Example 11, 87% for Inventive Example 12, 89% for Inventive Example 13, 89% for Inventive Example 14, 90% for Inventive Example 15, 87% for Inventive Example 16, 85% for Inventive Example 17, and 83% for Inventive Example 18.

[0134] In Examples 7 to 18 of the present invention, the salinity of the rearing water 110 was set to 0.007 to 0.500% by mass. As a result, it was confirmed that the average weight gain of the whiteleg shrimp was higher than the average weight gain of shrimp reared in a seawater environment with a salinity of 3.20% by mass. This allows the weight of saltwater shrimp A to increase more efficiently than in seawater. The same tendency was also observed in the amount of body length increase. This ensures that the growth of saltwater shrimp A can be promoted.

[0135] Furthermore, when comparing the weight gain and body length gain of Inventive Examples 7 to 18, it was confirmed that Inventive Examples 7 to 16 were higher than Inventive Examples 17 and 18. Therefore, by using rearing water 110 with a lower salinity concentration, the weight of saltwater shrimp A can be increased more efficiently.

[0136] In Comparative Example 5, the salt concentration of the rearing water 110 was set to 3.200% by mass. In other words, the salt concentration was not reduced from that of the rearing water 111. As a result, it was confirmed that the average weight gain of the whiteleg shrimp was lower than the average weight gain of the whiteleg shrimp reared in the rearing water 110 in which the salt concentration was reduced to 0.007 to 0.500% by mass. For this reason, the weight of the saltwater shrimp A could not be increased efficiently.

[0137] That is, the salt concentration of the rearing water 111 suitable for reliably promoting the growth of the saltwater shrimp A is 0.007 to 0.500 mass %, more preferably 0.007 to 0.250 mass %.

[0138] Furthermore, according to Table 2, when the salinity is 0.007 to 0.500% by mass, the survival rate is approximately 83% or more, when the salinity is 0.007 to 0.400% by mass, the survival rate is approximately 85% or more, and when the salinity is 0.007 to 0.010% by mass, the survival rate is approximately 90% or more.

[0139] That is, the salt concentration of the rearing water 110 suitable for improving the efficiency of land-based aquaculture of saltwater shrimp A and reliably promoting growth is 0.007 to 0.500 mass%, more preferably 0.007 to 0.400 mass%, and even more preferably 0.007 to 0.010 mass%.

[0140] <Experiment 3: Growth Promotion of Plant B> Next, a verification experiment on the effectiveness of different salinity concentrations of the culture water 110 used in the aquaponics system 2 according to the present invention in promoting the growth of plant B will be described. Specifically, the average fresh weight and average size of the edible portion of plant B grown in the culture water 110 and seawater (salinity of approximately 3% by mass) were measured over a 35-day growth period, and the growth promotion effect of plant B was confirmed, particularly based on the weight gain. As a comparative example, the average fresh weight and average size of the edible portion of plant B grown using liquid fertilizer in a separate hydroponic culture tank not connected to the storage unit 11 were also measured over a 35-day growth period. Note that the 35-day growth period for plant B was after the salt concentration reduction period in Experiment 1, but groundwater was added to maintain the water volume in the event of a decrease in water volume due to water absorption or evaporation by plant B. Therefore, the salt concentration may decrease even after the salt concentration reduction period.

[0141] In this experiment, chives and sweet basil were used as plant B, which were confirmed to be able to be grown by supplying rearing water 110, etc., adjusted to a rearing environmental temperature of 25 to 34°C for saltwater shrimp A, to plant B in hydroponic cultivation tank 21 without adjusting the temperature. The number of chives and sweet basil used in each experiment was 150 per condition (per test plot).

[0142] In the single hydroponic cultivation tank using liquid fertilizer, the water temperature was adjusted to approximately 26 to 30°C. The single hydroponic cultivation tank was a combination of an NFT type and a DWC type. The liquid fertilizer used was chemical liquid fertilizer Just One (registered trademark). The hydroponic cultivation tank 21 in Aquaponics 2 was filled with food for saltwater shrimp A and calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ The components of the water used for cultivation differ in that the water used for cultivation is rich in fertilizers containing ...

[0143] In this experiment, the average fresh weight of the edible part of Chinese chive and sweet basil was measured by calculating the average fresh weight of the edible part (stems and leaves) for 10 plants randomly selected from the total number of plants. Similarly, the average height of the edible part was calculated by calculating the average height of the edible part (stems and leaves) for 10 plants randomly selected from the total number of plants.

[0144] The salt concentrations of the rearing water 110 compared in this experiment were "0.007 to 0.200 mass%" (Invention Example 19), "0.300 mass%" (Invention Example 20), "0.500 mass%" (Invention Example 21), and "3 mass%" (Comparative Example 6). Of these, salt concentrations of 0.007 to 0.50 mass% according to the present invention were designated Inventive Examples 19 to 21, respectively. Comparative Example 6 was an example in which plants were grown using seawater with a salt concentration of approximately 3 mass%. Comparative Example 7 was an example in which plants were grown using liquid fertilizer in a single hydroponic cultivation tank. Within the salt concentration range of "0.007 to 0.200 mass%," there was no change in the average fresh weight and average size of the edible portion of chives and sweet basil.

[0145] The results of this experiment are shown in Table 3.

[0146]

[0147] According to Table 3, the average fresh weight of the edible portion of the chives in each Example was 8.0 g / plant for Inventive Example 19, 7.8 g / plant for Inventive Example 20, 6.5 g / plant for Inventive Example 21, and 4.0 g / plant for Comparative Example 7. The average size of the edible portion of the chives in each Example was 26.0 cm / plant for Inventive Example 19, 23.0 cm / plant for Inventive Example 20, 20.0 cm / plant for Inventive Example 21, and 18.0 cm / plant for Comparative Example 7. The average fresh weight of the edible portion of the sweet basil in each Example was 163.0 g / plant for Inventive Example 19, 106.0 g / plant for Inventive Example 20, 99.0 g / plant for Inventive Example 21, and 98.0 g / plant for Comparative Example 7. The average size of the edible portion of the sweet basil in each example was 42.0 cm / plant for Inventive Example 19, 39.0 cm / plant for Inventive Example 20, 36.0 cm / plant for Inventive Example 21, and 36.0 cm / plant for Comparative Example 7. Comparative Example 6 could not be cultivated.

[0148] In Examples 19 to 21 of the present invention, the salt concentration of the rearing water 110 was set to 0.007 to 0.500% by mass. As a result, it was confirmed that the average fresh weight of the edible portion of the chives and sweet basil was higher than the average fresh weight of the edible portion of the chives and sweet basil grown in seawater and liquid fertilizer. This allows the weight of saltwater shrimp A and the weight of plant B to be increased efficiently. This ensures the growth of saltwater shrimp A and plant B, which are susceptible to salt damage or can grow in freshwater, to be promoted simultaneously.

[0149] Furthermore, when comparing the average fresh weight of the edible portion of Inventive Examples 19 to 21, it was confirmed that the weight was highest in the order of Inventive Example 19, Inventive Example 20, and Inventive Example 21. Therefore, by using rearing water 110 with a lower salt concentration, the weight of plant B can be increased more efficiently.

[0150] Furthermore, according to Table 3, it was confirmed that the average size of the edible portion of the chives and sweet basil in Examples 19 to 22 of the present invention was also larger than the average size of the edible portion of the chives and sweet basil grown in seawater and liquid fertilizer. This makes it possible to efficiently increase the body length of saltwater shrimp A and the body length of plant B. This makes it possible to more reliably promote the growth of saltwater shrimp A at the same time as plant B that is susceptible to salt damage or that can grow in freshwater.

[0151] In Comparative Example 6, plant B was grown using seawater with a salt concentration of about 3% by mass. As a result, chives and sweet basil could not be grown. Therefore, the weight of plant B could not be increased efficiently.

[0152] In Comparative Example 7, plant B was grown using liquid fertilizer in a single hydroponic cultivation tank. As a result, the average fresh weight and average size of the edible portion of chives and sweet basil were lower than those in the case of using Aquaponics 2. Therefore, the weight of plant B could not be increased efficiently.

[0153] That is, the salt concentration of the breeding water 111 suitable for reliably promoting the growth of the saltwater shrimp A at the same time as the plant B is 0.007 to 0.500 mass%, more preferably 0.007 to 0.300 mass%, and even more preferably 0.007 to 0.200 mass%.

[0154] <Experiment 4: Growth-promoting effect of saltwater shrimp A and plant B with or without green light and artificial aquatic plants> Next, for the aquaponics 2 according to the present invention, a verification experiment will be described regarding the effectiveness of irradiating the breeding water 110 with green light, generating oxygen nanobubble water, and installing artificial aquatic plants in promoting the growth of saltwater shrimp A and plant B.

[0155] Specifically, the weight gain and body length gain were calculated from the average weight and average body length (control group) on days 75, 80, and 90 of the rearing period for saltwater shrimp A that had been acclimated without green light irradiation, oxygen nanobubble water production, or aquatic plant installation, and the average weight and average body length on days 75, 80, and 90 of the rearing period for saltwater shrimp A that had been acclimated using the acclimation method of Experiment 1 described above, plus green light irradiation, oxygen nanobubble water production, and aquatic plant installation. The growth-promoting effect of saltwater shrimp A was confirmed, particularly based on the weight gain.

[0156] As in Experiment 3, the average fresh weight and size of the edible portion (control group) on the 20th and 35th days of the growth period for plant B grown without green light irradiation, oxygen nanobubble water production, or artificial aquatic plants was calculated from the average fresh weight and size of the edible portion on the 20th and 35th days of the growth period for plant B grown with green light irradiation, oxygen nanobubble water production, and artificial aquatic plants, and the weight increase in particular was used to confirm the growth-promoting effect of plant B.

[0157] Furthermore, the survival rate of saltwater shrimp A (control group) grown without green light irradiation, oxygen nanobubble water generation, or artificial aquatic plants after the end of the salinity reduction period and on the 90th day of the growth period was calculated, and the survival rate of saltwater shrimp A grown with green light irradiation, oxygen nanobubble water generation, and artificial aquatic plants after the end of the salinity reduction period and on the 90th day of the growth period was calculated, and the effect of improving the survival rate of saltwater shrimp A was confirmed.

[0158] In this experiment, whiteleg shrimp was used as saltwater shrimp A, and Chinese chives were used as plant B. The number of whiteleg shrimp used in each experiment was 100 per condition (one test plot). A 100 L aquarium capable of accommodating these shrimp was used as the storage unit 11. The number of Chinese chives used in each experiment was 30 per condition (one test plot).

[0159] Regarding the salinity in this experiment, the amount of reduction in the salinity of the breeding water 112 was set to 0.20 mass% / day, and the salinity of the breeding water 110 after the reduction in the salinity was completed was set to 0.20 mass%.

[0160] In this experiment, green light L was irradiated onto the rearing water 110 (rearing water 111, rearing water 112) using an illumination unit 57 installed above the housing unit 11. A 72W green LED work light manufactured by CREE was used as the illumination unit 57. The illumination condition was such that green light L was constantly irradiated during the rearing period.

[0161] In this experiment, oxygen nanobubble water was generated by blowing air into the breeding water 110 (breeding water 111, breeding water 112) using a bubble generator 53 connected to the storage unit 11. A known nanobubble generator capable of handling salinity concentrations of approximately 0.20% by mass to approximately 3.00% by mass was used as the bubble generator 53. The oxygen nanobubble water was generated under the condition that the bubble generator 53 was operated continuously during the breeding period.

[0162] In this experiment, a plurality of artificial aquatic plants 6 were placed at intervals of approximately 1 m on the inner bottom surface of the storage section 11. As the artificial aquatic plants 6, "artificial spawning algae" manufactured by Kyorin Corporation was used.

[0163] In addition, each experiment was performed twice to confirm reproducibility. The other experimental conditions were the same as in Experiment 3.

[0164] The results of the verification experiment on saltwater shrimp A for this experiment are as shown in Table 4. Inventive Example 22 shows a control area where neither green light irradiation nor oxygen nanobubble water was performed. Inventive Example 23 shows an experimental area where green light irradiation was performed but oxygen nanobubble water was not performed. Inventive Example 24 shows an experimental area where oxygen nanobubble water was performed but green light generation was not performed. Inventive Example 25 shows a control area where both green light irradiation and oxygen nanobubble water generation were performed. Artificial aquatic plants were installed in all areas.

[0165]

[0166] According to Table 4, the weight gain of the vannamei shrimps of each Example relative to Inventive Example 22 (control group) on day 75 of the rearing period was 5.0 g / head for Inventive Example 23, 4.7 g / head for Inventive Example 24, and 10.0 g / head for Inventive Example 25. Furthermore, the weight gain of the vannamei shrimps of each Example relative to Inventive Example 22 (control group) on day 80 of the rearing period was 6.2 g / head for Inventive Example 23, 6.0 g / head for Inventive Example 24, and 9.6 g / head for Inventive Example 25. Furthermore, the weight gain of the vannamei shrimps of each Example relative to Inventive Example 22 (control group) on day 90 of the rearing period was 5.9 g / head for Inventive Example 23, 4.7 g / head for Inventive Example 24, and 8.0 g / head for Inventive Example 25.

[0167] The body length increment of the vannamei shrimps of each Example relative to Inventive Example 22 (control group) on day 75 of the rearing period was 4.1 cm / head for Inventive Example 23, 3.8 cm / head for Inventive Example 24, and 5.8 cm / head for Inventive Example 25. Furthermore, the body length increment of the vannamei shrimps of each Example relative to Inventive Example 22 (control group) on day 80 of the rearing period was 3.9 cm / head for Inventive Example 23, 3.7 cm / head for Inventive Example 24, and 5.2 cm / head for Inventive Example 25. Furthermore, the body length increment of the vannamei shrimps of each Example relative to Inventive Example 22 (control group) on day 90 of the rearing period was 4.8 cm / head for Inventive Example 23, 4.2 cm / head for Inventive Example 24, and 5.9 cm / head for Inventive Example 25.

[0168] In Inventive Example 23, green light L was irradiated into the rearing water 110 via the lighting unit 57. As a result, it was confirmed that the average weight gain of the vannamei shrimp was higher than the average weight gain of the vannamei shrimp reared in an environment without irradiation with green light L. Therefore, the weight of saltwater shrimp A can be increased more efficiently than in the case without irradiation with green light L. Furthermore, the increase in body length showed a similar tendency. This ensures further growth promotion of saltwater shrimp A.

[0169] In Example 24 of the present invention, oxygen nanobubble water was generated by blowing air into the rearing water 110 using the air bubble generator 53. As a result, it was confirmed that the average weight gain of the vannamei shrimp was higher than the average weight gain of the vannamei shrimp reared in an environment without oxygen nanobubble water. Therefore, the weight of saltwater shrimp A can be increased more efficiently than in the case without oxygen nanobubble water. Furthermore, the increase in body length showed a similar tendency. This ensures further growth promotion of saltwater shrimp A.

[0170] In Inventive Example 25, irradiation with green light L and production of oxygen nanobubble water were carried out. As a result, it was confirmed that the average weight gain of the vannamei shrimp was higher than the average weight gain of the vannamei shrimp grown in an environment irradiated with green light L but without production of oxygen nanobubble water. Therefore, the weight of saltwater shrimp A can be increased more efficiently than in the case where irradiation with green light L and production of oxygen nanobubble water are not carried out. Furthermore, the increase in body length showed a similar tendency. This ensures further growth promotion of saltwater shrimp A.

[0171] In addition, the results of the verification experiment for plant B in this experiment are shown in Table 5. Artificial aquatic plants were also placed in all plots.

[0172]

[0173] According to Table 5, the average fresh weight increase in the edible portion of the chives in each Example relative to Inventive Example 22 (control group) on day 20 of the growing period was 0.0 g / plant for Inventive Example 23, 4.0 g / plant for Inventive Example 24, and 4.0 g / plant for Inventive Example 25. Furthermore, the average fresh weight increase in the edible portion of the chives in each Example relative to Inventive Example 22 (control group) on day 35 of the growing period was 0.0 g / plant for Inventive Example 23, 3.0 g / plant for Inventive Example 24, and 4.0 g / plant for Inventive Example 25.

[0174] The average increase in size of the edible portion of the chives in each example relative to Inventive Example 22 (control group) on day 20 of the growth period was 1.0 cm / plant for Inventive Example 23, 11.0 cm / plant for Inventive Example 24, and 12.0 cm / plant for Inventive Example 25. Furthermore, the average increase in size of the edible portion of the chives in each example relative to Inventive Example 22 (control group) on day 20 of the growth period was 0.0 cm / plant for Inventive Example 23, 6.0 cm / plant for Inventive Example 24, and 7.0 cm / plant for Inventive Example 25.

[0175] In Inventive Example 23, green light L was irradiated onto the rearing water 110 via the lighting unit 57. As a result, it was confirmed that the average fresh weight and average size of the edible portion of the chives were no different from the average fresh weight and average size of the edible portion of the chives grown in an environment without irradiation with green light L. This is thought to be because the environment was such that green light L was irradiated only onto the rearing water 110, and not onto the plant B.

[0176] In Example 24 of the present invention, oxygen nanobubble water was generated by blowing air into the rearing water 110 via the air bubble generator 53. As a result, it was confirmed that the average fresh weight of the edible portion of the chives was higher than the average fresh weight of the edible portion of chives grown in an environment without oxygen nanobubble water. Therefore, the weight of plant B can be increased more efficiently than in the case where oxygen nanobubble water is not generated. The same tendency was also observed in the average size of the edible portion. This ensures further growth promotion of plant B.

[0177] In Example 25 of the present invention, green light L was irradiated and oxygen nanobubble water was produced. As a result, it was confirmed that the average fresh weight of the edible portion of the chives was higher than the average fresh weight of the edible portion of chives grown in an environment where oxygen nanobubble water was produced without irradiating with green light L. Therefore, the weight of plant B can be increased more efficiently than in the case where green light L was irradiated and oxygen nanobubble water was not produced. The same tendency was also observed in the average size of the edible portion. This ensures further growth promotion of plant B.

[0178] Furthermore, the results of the verification experiment on saltwater shrimp A with the installation of artificial aquatic plants 6 for this experiment are as shown in Table 6. Example 26 of the present invention shows a control area in which green light irradiation, oxygen nanobubble water generation, and artificial aquatic plants were not performed. Example 27 of the present invention shows an experimental area in which artificial aquatic plants were installed, but green light irradiation and oxygen nanobubble water generation were not performed. Example 28 of the present invention shows an experimental area in which artificial aquatic plants were installed and green light irradiation was performed, but oxygen nanobubble water generation was not performed. Example 29 of the present invention shows an experimental area in which artificial aquatic plants were installed and oxygen nanobubble water was generated, but green light generation was not performed. Example 30 of the present invention shows a control area in which green light irradiation, oxygen nanobubble water, and artificial aquatic plants were installed.

[0179]

[0180] According to Table 6, the increase in survival rate of vannamei shrimp in each Example relative to Inventive Example 26 (control group) at the end of the salt concentration reduction period was 27% in all of Inventive Examples 27 to 30. Furthermore, the increase in survival rate of vannamei shrimp in each Example relative to Inventive Example 22 (control group) on day 90 of the rearing period was 20% in Inventive Example 27, 21% in Inventive Example 28, 22% in Inventive Example 29, and 25% in Inventive Example 30.

[0181] In Inventive Example 27, artificial aquatic plants 6 were placed in the housing section 11. As a result, it was confirmed that the survival rate of vannamei shrimp was higher than that of vannamei shrimp grown in an environment without the placement of artificial aquatic plants 6. Therefore, the survival rate of saltwater shrimp A can be improved compared to the case where the artificial aquatic plants 6 are not placed. This allows for further improvement in the efficiency of land-based culture of saltwater shrimp A.

[0182] In Inventive Example 28, artificial aquatic plants 6 were placed in the housing section 11, and green light L was irradiated onto the rearing water 110 via the lighting section 57. As a result, it was confirmed that the survival rate of vannamei shrimp was higher than that of vannamei shrimp reared in an environment without irradiation of green light L. Therefore, the survival rate of saltwater shrimp A can be improved compared to the case without irradiation of green light L. This allows for further improvement in the efficiency of land-based culturing of saltwater shrimp A.

[0183] In Example 29 of the present invention, artificial aquatic plants 6 were placed in the housing section 11, and air was blown into the rearing water 110 via the air bubble generator 53 to generate oxygen nanobubble water. As a result, it was confirmed that the survival rate of vannamei shrimp was higher than that of vannamei shrimp reared in an environment without generating oxygen nanobubble water. Therefore, the survival rate of saltwater shrimp A can be improved compared to when oxygen nanobubble water is not generated. This allows for further improvement in the efficiency of land-based aquaculture of saltwater shrimp A.

[0184] In Example 30 of the present invention, artificial aquatic plants 6 were placed in the storage section 11, and then green light L was irradiated and oxygen nanobubble water was generated. As a result, it was confirmed that the survival rate of vannamei shrimp was higher than that of vannamei shrimp grown in an environment where either green light L was irradiated or oxygen nanobubble water was generated. Therefore, the survival rate of saltwater shrimp A can be improved compared to when either green light L was irradiated or oxygen nanobubble water was generated. This allows for further improvement in the efficiency of land-based aquaculture of saltwater shrimp A.

[0185] <Experiment 5: Survival Rate Improvement Effect on the Survival Rate of Saltwater Shrimp A> The following describes the details of the relationship between the rearing water 111 and the survival rate of saltwater shrimp A, by comparing an example in which the component ratios of the above-described embodiment are used with a comparative example. In this experimental example, the rearing water 111 was not subjected to an operation of reducing the salt concentration to prepare the rearing water 110, and the survival rate of saltwater shrimp A before acclimation was confirmed. Therefore, the contents of the subsequent experiments will be described as a "reference example" and a "comparative example." However, it goes without saying that a similar improvement in survival rate can be achieved when the rearing water 110, the salt concentration of which has been reduced by the salt concentration reduction step S11, is combined with the acclimated saltwater shrimp A.

[0186] In this experiment, the rearing water 111 in which the saltwater shrimp A was reared contained Mg as the mass of solute per 1 L of rearing water. 2+ , Ca 2+ , K. + The survival rates of the saltwater shrimp A at each mass and mass ratio were compared to confirm the production efficiency of the saltwater shrimp A. The survival rate in this example was the survival rate of the saltwater shrimp A on the 90th day after the start of rearing from the seed shrimp juveniles.

[0187] The breeding water 111 contains Mg 2+ , Ca 2+ , K. + In addition, SO4 2- Approximately 50mg / L, Sr 2+ Artificial seawater containing approximately 8 mg / L of strontium ions and a salinity of approximately 3.2% was used. 2- Concentration, Sr 2+The concentration and salinity were not intentionally increased or decreased.

[0188] The mass of solutes in the rearing water 111 compared in this experiment was Mg as the mass of solutes per 1 L of rearing water. 2+ 25 to 350 mg, Ca 2+ 20 to 320 mg, K + The dose was set to a number of combinations selected between 5 and 90 mg. The other experimental conditions were the same as in Experiment 1.

[0189] Also, Mg 2+ , Ca 2+ , K. + For each of the above, a first mass ratio (Mg 2+ mass / K + mass), second mass ratio (Ca 2+ mass / K + ), and the third mass ratio (Mg 2+ Mass of Ca 2+ The survival rate of the saltwater shrimp A was calculated as follows: over 60% was evaluated as "good" and less than 60% was evaluated as "bad." 2+ , Ca 2+ , K. + The mass combinations and mass ratios were confirmed.

[0190] <Experimental Results Regarding Survival Rate of Saltwater Shrimp A> The results of this experiment are shown in Table 7.

[0191]

[0192] According to Table 7, the survival rates of the vannamei shrimp in each example with "Evaluation: ○" are as follows: Reference Example 1 (Mg 2+ :240mg / L, Ca 2+ :180mg / L, K + : 60 mg / L) was 99%, Reference Example 2 (Mg 2+ :45mg / L, Ca 2+ : 60 mg / L, K + : 30 mg / L) was 92%, Reference Example 3 (Mg 2+ :40mg / L, Ca 2+ : 60 mg / L, K + : 20 mg / L) was 91%, Reference Example 4 (Mg 2+:30mg / L, Ca 2+ : 30 mg / L, K + : 30 mg / L) was 89%, Reference Example 5 (Mg 2+ :40mg / L, Ca 2+ : 30 mg / L, K + : 60 mg / L) was 86%, Reference Example 6 (Mg 2+ :200mg / L, Ca 2+ :200mg / L, K + : 50 mg / L) was 82%, Reference Example 7 (Mg 2+ :200mg / L, Ca 2+ :120mg / L, K + : 40 mg / L) was 78%, Reference Example 8 (Mg 2+ :320mg / L, Ca 2+ :250mg / L, K + : 80 mg / L) was 78%, Reference Example 9 (Mg 2+ :35mg / L, Ca 2+ : 25 mg / L, K + : 8 mg / L) was 76%, Reference Example 10 (Mg 2+ :60mg / L, Ca 2+ : 50 mg / L, K + In Reference Examples 1 to 10, the survival rate was over 60%, and therefore the evaluation was "good."

[0193] In Reference Examples 1 to 10, the rearing water 111 contains 35 to 320 mg of Mg as the mass of solute per 1 L of rearing water. 2+ and 25-250 mg of Ca. 2+ and 8 to 80 mg of K. + and wherein the first mass ratio is 0.7 to 5.0, the second mass ratio is 0.5 to 5.0, and the third mass ratio is 0.7 to 1.4. As a result, the survival rate of saltwater shrimp A can be increased to 75% or more. This can reliably improve the production efficiency of saltwater shrimp A.

[0194] In particular, it was confirmed that the survival rate was even higher, that is, 78% or higher when the third mass ratio was 0.7 to 1.3 (Reference Examples 1 to 8), 82% or higher when the first mass ratio was 0.7 to 4.0 and the second mass ratio was 0.5 to 4.0 (Reference Examples 1 to 6), 89% or higher when the first mass ratio was 1.0 to 4.0 and the second mass ratio was 1.0 to 3.0 (Reference Examples 1 to 4), and 91% or higher when the first mass ratio was 1.5 to 4.0 and the second mass ratio was 2.0 to 3.0 (Reference Examples 1 to 3). This allows for even more reliable improvement in the production efficiency of saltwater shrimp A.

[0195] The survival rates of the vannamei shrimp in each example with an "Evaluation: ×" were as follows: Comparative Example 8 (with Mg 2+ :320mg / L, Ca 2+ :250mg / L, K + : 90 mg / L) was 52%, Comparative Example 9 (Mg 2+ :320mg / L, Ca 2+ :260mg / L, K + : 80 mg / L) was 52%, Comparative Example 10 (Mg 2+ :350mg / L, Ca 2+ :320mg / L, K + : 80 mg / L) was 48%, Comparative Example 11 (Mg 2+ :30mg / L, Ca 2+ : 35 mg / L, K + : 8 mg / L) was 32%, Comparative Example 12 (Mg 2+ :35mg / L, Ca 2+ : 20 mg / L, K + : 8 mg / L) was 30%, Comparative Example 13 (Mg 2+ :320mg / L, Ca 2+ : 20 mg / L, K + : 80 mg / L) was 12%, Comparative Example 14 (Mg 2+ :350mg / L, Ca 2+ : 35 mg / L, K + : 8 mg / L) was 8%, Comparative Example 15 (Mg 2+ :35mg / L, Ca 2+ :260mg / L, K + : 8 mg / L) was 8%, Comparative Example 16 (Mg 2+ :35mg / L, Ca 2+ : 25 mg / L, K+ : 90 mg / L) was 5%, Comparative Example 17 (Mg 2+ :25mg / L, Ca 2+ : 35 mg / L, K + : 5 mg / L) was 5%, Comparative Example 18 (Mg 2+ :250mg / L, Ca 2+ :320mg / L, K + : 5 mg / L) was 4%, Comparative Example 19 (Mg 2+ :30mg / L, Ca 2+ :320mg / L, K + : 80 mg / L) was 2%.

[0196] In Comparative Example 8, K + Since the concentration of the saltwater shrimp A exceeds 80 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0197] In Comparative Example 9, Ca 2+ Since the concentration of the saltwater shrimp A exceeds 250 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0198] In Comparative Example 10, Mg 2+ Since the concentration of the saltwater shrimp A exceeds 320 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0199] In Comparative Example 11, Mg 2+ Since the concentration of the saltwater shrimp A is less than 35 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0200] In Comparative Example 12, Ca 2+ Since the concentration is less than 25 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0201] In Comparative Example 13, Ca 2+ Since the concentration is less than 25 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0202] In Comparative Example 14, Mg 2+Since the concentration of the saltwater shrimp A exceeds 320 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0203] In Comparative Example 15, Ca 2+ Since the concentration of the saltwater shrimp A exceeds 250 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0204] In Comparative Example 16, K + Since the concentration of the saltwater shrimp A exceeds 80 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0205] In Comparative Example 17, K + Since the concentration of the saltwater shrimp A is less than 8 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0206] In Comparative Example 18, K + Since the concentration of the saltwater shrimp A is less than 8 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0207] In Comparative Example 19, Mg 2+ Since the concentration of the saltwater shrimp A is less than 35 mg / L, the survival rate of the saltwater shrimp A cannot be increased, and the production efficiency of the saltwater shrimp A cannot be reliably improved.

[0208] That is, the breeding water 111 before the reduction in the salinity concentration and the breeding water 110 after the reduction in the salinity concentration, which are suitable for improving the survival rate of the saltwater shrimp A, have a solute mass of 35 to 320 mg Mg per 1 L before and after the salt concentration reduction step S11. 2+ and 25-250 mg of Ca. 2+ and 8 to 80 mg of K. +and wherein the first mass ratio is 0.7 to 5.0, the second mass ratio is 0.5 to 5.0, and the third mass ratio is 0.7 to 1.4. More preferably, the third mass ratio is 0.7 to 1.3, even more preferably, the first mass ratio is 0.7 to 4.0 and the second mass ratio is 0.5 to 4.0, even more preferably, the first mass ratio is 1.0 to 4.0 and the second mass ratio is 1.0 to 3.0, and even more preferably, the first mass ratio is 1.5 to 4.0 and the second mass ratio is 2.0 to 3.0.

[0209] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0210] 1 Acclimation system 11 Storage unit 110 Rearing water (Rearing water in which the salinity concentration has been reduced) 111 Rearing water (Rearing water with a salinity concentration at which marine organisms can survive) 112 Rearing water (Rearing water in which the salinity has been reduced) 12 Salinity reduction unit 13 Water supply tank 130 Dilution water 14 Wastewater tank 140 Wastewater 2 Aquaponics 21 Hydroponic cultivation tank 210 Rearing water 22 Decomposition liquid generation unit 220 Decomposition liquid 23 Decomposition liquid supply unit 31, 31a, 31b Circulation piping 32 Water supply piping 33 Drainage piping 51 Filtration device 52 Disinfection device 53 Bubble generator 54 Water quality monitoring device 55 Temperature control device 56 Automatic feeding device 57 Lighting unit 6 Artificial aquatic plants A Saltwater shrimp B Plants L Green light S11 Salt concentration reduction step S21 Decomposition liquid production step S22 Decomposition liquid supply step

Claims

1. A method for acclimatizing saltwater shrimp, characterized by comprising a step of reducing the salt concentration of the rearing water in which the saltwater shrimp are reared by 0.10 to 0.50% by mass per day.

2. The method for acclimatizing saltwater shrimp according to claim 1, wherein the salinity reduction step involves generating oxygen microbubble water or oxygen nanobubble water by blowing a gas containing at least oxygen into the rearing water.

3. The method for acclimatizing saltwater shrimp according to claim 1 or 2, characterized in that the salinity reduction step reduces the salinity of the rearing water while irradiating it with green light.

4. The method for acclimatizing saltwater shrimp according to claim 1 or 2, characterized in that the salinity reduction step reduces the salinity of the rearing water in a storage section in which artificial aquatic plants have been placed beforehand.

5. The rearing water has a solute mass of 35 to 320 mg Mg per 1 L of the rearing water before and after the salt concentration reduction process. 2+ and 25-250 mg of Ca 2+ and 8 to 80 mg of K + and, including K + Mg relative to the mass of 2+ a first mass ratio indicating a mass ratio of + Ca relative to the mass of 2+ The second mass ratio is 0.5 to 5.0, and Ca 2+ Mg relative to the mass of 2+ The method for acclimatizing saltwater shrimp according to claim 1 or 2, wherein a third mass ratio indicating a mass ratio of 6. An aquaponics cultivation method comprising: a salt concentration reduction step of reducing the salt concentration of breeding water in which saltwater shrimp are raised by 0.10 to 0.50 mass % per day; a decomposition solution production step of producing a decomposition solution by biodegrading excrement of the saltwater shrimp; and a decomposition solution supply step of supplying the decomposition solution produced in the decomposition solution production step to plants hydroponically cultivated in the breeding water whose salt concentration has been reduced in the salt concentration reduction step.

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