JP7169502B2 - aquaculture method of aquatic animals - Google Patents

Description

The present invention relates to aquaculture methods for aquatic animals, and more particularly to aquaculture methods that do not use chemicals such as antibiotics.

Wild and farmed shrimp are harvested worldwide including Japan, Korea, Taiwan, Vietnam, the Philippines, Australia, Malaysia, and India. In particular, vannamei shrimp and kuruma prawns are in high demand because of their favorable taste.

In Taiwan, Vietnam, the Philippines, etc., farms are established in brackish water lagoons (lagoons) where seawater and freshwater are mixed to cultivate juvenile shrimp and the like. On the bottom of the lagoon, uneaten shrimp feed, shrimp excrement, exuviae, dead shrimp, etc. tend to settle. If much of the sedimentation is not discharged and rots, the water quality of the lagoon deteriorates and becomes a source of disease-causing bacteria.

In the early stages of juvenile shrimp farming, there was no invasion of shrimp diseases, and the shrimp farming industry prospered. Since the first occurrence of White Spot Disease (WSD) in Taiwan in 1993 due to changes in the environment, white spot disease, luminos bacteria disease, taura syndrome, infectious subcutaneous hematopoietic necrosis, Diseases such as Vibrio infections are occurring in various places. And with the expansion of the shrimp farming business, the spread of the disease is becoming more serious.

As a countermeasure against diseases of aquatic animals such as shrimp, it is common practice to administer antibiotics and fungicides during aquaculture and storage in fish cages. Considering the fact that aquatic animals grow while taking pathogens and chemicals into their bodies, there is concern about the adverse effects on the human body that eats them.

Vietnam had a successful shrimp farming business in the 1960s, bringing high incomes to shrimp farmers. In the 1990s, aquaculture rapidly increased, causing epidemics such as white spot disease in shrimp, resulting in great losses for aquaculture farmers. The cause of the loss is a decline in shrimp yields due to worsening environmental pollution leading to disease, an increase in production costs due to the extensive use of antibiotics and fungicides to secure yields, and the emergence of drug-resistant bacteria. Further increases in drug costs, a decrease in the value of shrimp that have grown with pathogenic bacteria and chemicals, and a decrease in sales due to avoidance. In order to supply healthy shrimp and benefit the aquaculture industry, the above vicious circle needs to be broken.

Conventionally, in conventional aquaculture breeding at the larvae stage (larvae shrimp, etc.), mass mortality of larvae frequently occurred, and the growth yield sometimes became 10% or less. A cultivation method that improves the growth yield in the larval stage is desired.

In order to increase the yield of adult aquatic animals such as shrimp and fish in farms, there is a desire to increase rearing density. However, increasing stocking density also increased mortality and did not lead to increased yields. For example, in conventional shrimp farming methods, the maximum breeding density is 100 fish/m ² . A farming method that improves breeding density in the juvenile stage is desired.

Patent Document 1 discloses water preparation for a freshwater aquaculture pond, which is characterized by stabilizing the water quality by using a soil activator (hereinafter referred to as a bacteria group) in which effective bacteria are mixed with humus soil and animal organic matter in the aquaculture pond. Suggest. Table 2 shows the results of aquaculture of the breeding fish (Ryukin). The survival rate of the bacteria population in Trial 2 was little improved compared to the Trial 1 control. Moreover, the average body weight of the caught fish in the test plot 2 decreased more than that in the test plot 1. Therefore, the technique of Patent Document 1 is not an aquaculture method that raises the breeding density of juvenile fish and increases the yield.

Japanese Patent Application Laid-Open No. 54-97298 JP 2006-273734 JP 2011-74047

As described above, conventional aquaculture has made heavy use of chemicals such as antibiotics and fungicides in order to prevent infectious diseases and maintain yields. Environments requiring chemicals are not healthy for aquatic animals. An object of the present invention is to provide a method for cultivating safe and healthy aquatic animals as food for humans by creating conditions suitable for the growth of aquatic animals without relying on chemicals, enhancing the natural healing power of aquatic animals. to do.

The aquaculture method described above provides a method of improving the growth yield of aquaculture, among other things. The above farming method also provides a farming method that can raise juvenile fish healthily and increase the yield of adult fish even if the rearing density is increased more than before.

The present inventors have studied the above problems more specifically. The stresses that aquatic animals undergo during cultivation are (1) environmental stresses such as excessive breeding density, water temperature fluctuations, pH fluctuations, BOD rise, contaminant invasion, and red tide, and (2) food, excrement, molting debris, carcasses, etc. and (3) bacterial and viral infection stress. Conventional administration of antibiotics and the like can only deal with (3) infectious viruses.

When aquatic animals are subjected to at least one of the above stresses, it leads to slow growth and mass mortality of juvenile fish and shrimp. For example, in marine fish farms, 99% or more of marine fish die during the larval stage up to 20 days after hatching. In particular, in shrimp farming sites, mass mortality occurs during the rearing stage of larval shrimp. In order to establish a natural management method that does not use chemicals or the like, it is necessary to comprehensively eliminate or prevent the above stress.

The basic measures for feeding aquatic animals in aquaculture farms with plankton and food normally and growing them into healthy adult shrimp and adult fish are conditions such as water temperature, plankton (plants and animals), oxygen concentration, pH, and sunlight. It is to adjust it to be suitable for aquaculture of aquatic animals. However, these adjustments alone cannot establish a safe aquaculture method that utilizes the natural healing power of aquatic animals.

The present inventors have unexpectedly discovered that correcting the environment surrounding aquatic animals in aquaculture farms by the specific action of humic substances and the microorganisms contained therein provides a comprehensive relief of the above stresses. Then, by increasing the natural healing power of aquatic animals, they succeeded in raising them to adulthood without the help of chemicals such as antibiotics. Moreover, it has become possible to increase the growth yield in the larval stage and increase the breeding density and yield in the juvenile stage.

That is, the present invention is an aquaculture method for an aquatic animal farm, wherein the aquaculture method includes culturing the aquatic animal in the presence of humic substances, and the humic substances proliferate algalytic microorganisms. and adjusting the input amount of the humic substance so as to adjust the plankton concentration in the farm and reduce the BOD. In the present specification, aquatic animals are used to mean all animals living in seawater, freshwater and brackish water.

The technique of Patent Document 1 teaches and suggests that humic substances that grow algalytic microorganisms are introduced into the farm and the amount of humic substance used is adjusted so as to properly manage the plankton concentration and BOD in the farm. Neither did

The above-mentioned humic substance for growing algalytic microorganisms is particularly obtained by lightening humus soil at a moisture content of 50 to 80%. In the present specification, light reaction means maturing and fermenting excavated humus soil under sunlight without drying while maintaining a constant moisture content.

Said aquaculture is characterized by improving the growth yield, especially in the larval stage.

If the aquaculture improves larval stage growth yield, the farm is preferably a post-larva tank for the larval stage.

Said aquaculture is characterized by increasing the rearing density, especially during the juvenile stage.

If the farming increases the breeding density of the juvenile stage, the farm is preferably a juvenile stage aquaculture pond.

Said aquatic animals are, for example, crustaceans.

In the aquaculture method for aquatic animals of the present invention, when juvenile shrimp or juvenile fish are cultivated into adult shrimp or adult fish at a farm, humic substances are added to proliferate algalytic microorganisms in the farm to produce phytoplankton and zooplankton. Properly control concentrations, decompose organic matter, and prevent disease transmission. The aquaculture method of the present invention comprehensively prevents (1) environmental stress, (2) putrefaction stress, and (3) infection stress, and cultivates aquatic animals in a healthy manner without using chemicals such as antibiotics. becomes possible.

There are vertical and horizontal transmissions of diseases during the aquaculture process from larval to juvenile and adult shrimps. Vertical infection is parent-child infection by selection of parent shrimp used for fertilized eggs and seedling production, and can be prevented by selection that does not cause parent-child infection. Horizontal infection, on the other hand, is infection from individual to individual through contact, food, feces, dissolved oxygen, and the like. The present invention prevents infectious stress from horizontal infection.

Relief and prevention of the above stress is demonstrated by improvement in the growth yield of larval shrimp in the larval stage, as shown in the Examples below. In conventional larval stage aquaculture, the environment, putrefaction, and environmental stress caused mass mortality of larval shrimp, and the growth yield was sometimes reduced to 10% or less. On the other hand, according to the culture method of the present invention, a growth yield of 98% was achieved.

The elimination and prevention of stress is also demonstrated by the achievement of a higher breeding density than before, as shown in the examples below. In conventional shrimp farming, the maximum breeding density was 100 fish/m ² even when chemicals such as antibiotics were used. On the other hand, according to the aquaculture method of the present invention, a yield of 90% was maintained even when aquaculture was carried out at a rearing density of 150 fish/m ² .

More preferably, the present invention further prevents environmental stress, etc., by controlling appropriate feed supply by, for example, a feeding table, appropriate water temperature and pH, salinity, dissolved oxygen concentration, BOD, etc., by introducing a regulating pond, for example. and can promote the growth of aquatic animals.

If chemicals such as antibiotics are used as a countermeasure against diseases during shrimp farming, there is a risk that the antibiotics will enter animals including humans. The humic substances used in the aquaculture method of the present invention are natural substances. Humic substances do not adversely affect animals such as humans even if they enter through aquatic animals. Its main component, fulvic acid, not only activates the growth of microorganisms, but also has physiological activities useful for the growth and immunity improvement of aquatic animals. It is expected that the useful physiological activity of humic substances in aquatic animals will have a favorable effect on humans.

1 shows an embodiment of a farm flow for carrying out the farming method of the present invention. The aquaculture farm 1 of this example is divided into a post-larva tank 200 for cultivating juvenile aquatic animals to a juvenile stage, and an aquaculture pond 300 for cultivating juvenile aquatic animals to adulthood.

The aquaculture method of the present invention (hereinafter referred to as the aquaculture method of the present invention) will be described below. The aquaculture method of the present invention includes cultivating the aquatic animal in the presence of humic substances, the humic substances proliferating algalytic microorganisms, adjusting the plankton concentration in the farm, and reducing BOD. The input amount of the humic substance is adjusted as follows.

The subject of the aquaculture method of the present invention is not particularly limited as long as it is an aquatic animal. Aquatic animals may be freshwater or marine animals. Examples of aquatic animals include crustaceans such as kuruma prawns, vanname shrimps, cherry shrimps, long prawns, krill and crabs; Fish such as red sea bass, horse mackerel, striped horse mackerel, blowfish, tuna, crucian carp, sweetfish, rainbow trout, and carp (including ornamental fish such as goldfish and colored carp); squid, octopus, eel, and sea squirt. Sea urchins, sea cucumbers, aquatic mammals, etc. are included.

In the aquaculture method of the present invention, the reason why the humic substance having the above-mentioned action eliminates or prevents environmental stress and the like will be explained. Phytoplankton (microscopic algae such as diatoms) that live in seawater such as aquaculture ponds and post-larva tanks in aquaculture farms take bicarbonate ions (HCO ₃ ^- ) in seawater directly into their cells, and further carbonic dehydration. Under the enzyme, it is converted into carbon dioxide and OH ^- according to the following formula (1).
HCO ₃ ^- → CO ₂ + OH ^- (1)

Carbon dioxide is converted into organic matter (glucose) and oxygen by the photosynthetic action of phytoplankton according to the following formula (2).
_{6CO2 + 6H2O} → _{C6H12O6 +} 6O2 ( ₂ )

This photosynthesis results in an increase in dissolved oxygen concentration and BOD in the pond. There is no problem with dissolved oxygen, and it is rather favorable for the respiration of aerobic microorganisms. On the other hand, BOD is an index of water pollution, and water quality deteriorates when BOD increases.

Nutrients such as silicates, phosphates, nitrates, and nitrites are dissolved in post-larva tanks and aquaculture ponds. When nutrient salts are abundantly dissolved, phytoplankton easily grow algae under sunlight.

Phytoplankton becomes food for aquatic animals such as juvenile shrimp, and its concentration (breeding amount) may be within a range that allows feeding. When phytoplankton propagates excessively, algae develops, and seawater becomes alkaline due ^to the generation of OH-. It is said that the optimum pH for juvenile shrimps to grow healthily is around pH=7 to 9, but the pH can be as high as about 11 in ponds with abnormal algal blooms. In this pH range, algae accumulate on the bottom of aquaculture ponds and rot, causing offensive odors and pathogen infection.

In the aquaculture method of the present invention, a series of problems such as phytoplankton proliferation and algae growth, pH increase, organic matter generation, BOD increase, putrefaction, pathogen invasion, etc., are solved at once by the action of humic substances shown below.

When the humic substance is added to the tank, algalytic microorganisms grow in the tank. The grown microorganisms prey on the phytoplankton in the tank and dissolve and eliminate the algae. This algal dissolution action keeps the phytoplankton concentration in the tank within an appropriate range. The pH is stabilized between 7 and 9, obviating algae settling and spoilage.

Algalytic microorganisms and other microorganisms that proliferate with the addition of humic substances prey on organic matter in seawater, exhulled shells, shrimp droppings, food leftovers, etc., and reduce or eliminate BOD. By promoting this water purification, invasion of pathogens is prevented.

Fulvic acid, a component of humic substances, has antibacterial and antiviral properties. Infectious diseases are more effectively prevented by the synergistic action of the above-mentioned microorganisms and humic substances.

In conventional aquaculture, viral infectious diseases such as white spot disease and bacterial infectious diseases such as luminos bacteria were contagious, and no effective aquaculture could be obtained without the use of antibiotics. According to the present invention, larval shrimp can be cultured by adding humic substances without using antibiotics or the like.

Microorganisms grown by the addition of humic substances also serve as food for aquatic animals. Humic substances taken in by aquatic animals have the ability to remove unnecessary active oxygen (antioxidant properties). This antioxidant property prevents the aging and disease of the body and improves immunity. Improving immunity is of utmost importance, especially for the development of larval shrimp.

The active oxygen removing action of humic substances is also useful for cultivating high-quality plankton that produces carotenoids. Since cultured shrimp with a red body color are generally preferred, supplying humic substance to the postlarva tank or culture pond is also advantageous in that healthy red shrimp can be raised.

When humic substances are added, microorganisms prey on phytoplankton and proliferate. Growing microorganisms and zooplankton that prey on them also multiply. Humic substances increase zooplankton while suppressing algae growth of phytoplankton. Zooplankton growth is particularly advantageous during the later stages of postlarvae and fry-to-adult cultures.

Phytoplankton may not grow despite the presence of nutrients and sunlight. The aquaculture method of the present invention is useful for the growth of phytoplankton because humic substances supply iron necessary for photosynthesis.

The humic substance for growing algalytic microorganisms can be produced, for example, according to the methods described in Patent Documents 2 and 3. The contents of US Pat.

The humic substance for growing algalytic microorganisms can be obtained by lightening humus soil at a moisture content of 50 to 80%. The light reaction under constant water content converts the coenzyme NADP (oxidized form, nicotinamide adenine dinucleotide phosphate) produced in the dark reaction to NADPH2 (reduced form) and further liberates hydrogen ions. ADP produced in the dark reaction is converted to ATP in the light reaction. Biological reactions can be further activated by the production of coenzymes by this photoreaction.

Specifically, the humus soil is obtained by burying the fallen leaves of deciduous trees, decomposition and biosynthetic products derived from organic matter such as trees, for example, for about 8000 years or more, and turning them into humus. . After excavating such humus soil, light reaction is carried out. That is, it is left under sunlight for usually 1 to 12 months, preferably 3 to 12 months, particularly preferably 6 to 12 months. The moisture content of the above-ground humus soil is 50-80%, preferably 50-70%, more preferably 50-65%, and it is necessary to maintain a moisture content suitable for fermentation. In order to allow the whole humus to undergo a light reaction (fermentation and maturation) uniformly, it is preferable to cut the humus from time to time. The humus soil is neutral with a pH of about 7 at the time of excavation, but as lightening reaction proceeds on the ground, the pH becomes about 3 after one month. Even after one year has passed, there is no significant change in pH, and the pH becomes 2.6 to 3.3.

Activation of humic substances may be improved by adding magnesium calcium acetate hydrate to the obtained humus. In addition to the above components, cysteine, which is a type of amino acid, may be added and mixed as appropriate. In order to smoothly grow microorganisms including algalytic microorganisms, it is preferable to mix pumice with the humus. In particular, pumice containing as many kinds of minerals as possible is preferable.

Table 1 shows the antibacterial test results of a humic substance obtained by photoreacting humus soil (hereinafter referred to as humic substance A). Tables 1 and 2 show the in vitro antibacterial and antiviral test results of the humic substance (hereinafter referred to as humic substance B) obtained by lightly reacting the humus soil, adding calcium magnesium acetate, and further fermenting and aging it. .

An in vitro antiviral test using the above humic substance A or B with white spot virus, which is well known in shrimp farming, has not been conducted due to the difficulty in obtaining the virus. In the actual shrimp farming test in Example 1 described later, the fact that juvenile shrimp grew into healthy adults with a high yield of 90% by adding humic substances (humic powder and humus pellets) to the farming pond was confirmed by the above-mentioned humus. It demonstrates that the substance prevents white spot virus.

The humic substance that grows algalytic microorganisms and has the antibacterial/antiviral activity may be commercially available. Examples thereof include humic powder EZ-70 and humus pellet EZ-201 (both manufactured by Enzyme Co., Ltd.).

In aquatic animal farms, the environment of breeding facilities such as postlarva tanks and aquaculture ponds, and food such as phytoplankton, zooplankton and feed, changes according to the stage of growth. The aquaculture method of the present invention flexibly responds to changes in breeding facilities and feed environments as described below.

The post-larva tank is a facility for rearing aquatic animals in the larval stage (for example, larval shrimp). The food environment changes as follows from egg hatching to larval shrimp development. In the early stages of the larval shrimp, it feeds on phytoplankton to promote growth into postlarva shrimp. As the larval shrimp transition to postlarvae, they feed on phytoplankton and zooplankton. In the aquaculture method of the present invention, larval shrimps are supplied with phytoplankton proliferated by sunlight in the presence of humic substances. Grown larval shrimp can be supplied with microorganisms grown in humic substances and zooplankton that prey on them.

The post-larva tank is installed in a bright place exposed to sunlight so that phytoplankton can grow by photosynthesis. If it is in a dark place such as a room, not only will phytoplankton not proliferate, but the phytoplankton will settle and rot at the bottom, causing deterioration of water quality. In addition, a net may be provided on the upper part of the post-larva tank so as to keep the inside of the tank bright and not be harmed by birds and the like.

In larval breeding of aquatic animals such as shrimp, the smaller the breeding age, the higher the mortality rate. When the concentration of phytoplankton becomes high, the water quality deteriorates, and it is easy for growth failure to occur. In larval rearing, it is important to maintain an appropriate concentration of phytoplankton. In the aquaculture method of the present invention, by controlling the concentration of phytoplankton by the algalytic action of the grown microorganisms, it is possible to achieve a balance between feeding phytoplankton and water purification. Therefore, the aquaculture method of the present invention is used to improve growth yield, especially in aquatic animal farms. For example, it is possible to achieve a growth yield of larval shrimp of usually 80% or more, preferably 90% or more, particularly preferably 95% or more at the time of input.

By the aquaculture method described above, larva stage aquatic animals grow into juvenile fish with enhanced natural healing power and resistance. For example, in the case of shrimp farming, juvenile shrimp develop into postlarva shrimp (juvenile shrimp that are transferred to aquaculture ponds for further growth) that are 2-3 cm long and weigh around 0.5 g.

Aquaculture ponds are facilities for rearing juvenile aquatic animals to adulthood. Juvenile fish in aquaculture ponds prey on zooplankton rather than phytoplankton. In the aquaculture method of the present invention, humic substances are introduced into the aquaculture pond to proliferate microorganisms and zooplankton that prey on them, and these become food for juvenile fish.

In addition to zooplankton, proper food supply is also required for juvenile breeding. When the amount of food is small, the variability of grown individuals increases. Conversely, if the amount of food becomes excessive, it will accumulate on the bottom of the pond, causing rot and deterioration of water quality. In the aquaculture method of the present invention, the presence of humic substances prevents the spoilage of feed and the deterioration of water quality caused by it.

A high-quality diet containing carotenoids, folic acid, and vitamins is beneficial for the growth of aquatic animals. Red shrimp contains carotenoids, particularly astaxanthin, which is a type of carotenoid. Carotenoids have antioxidant properties and improve the immunity of aquatic animals such as shrimp. Improving immunity is most important for the development of larval shrimp, so it is preferable to feed aquatic animals such as red shrimp with carotenoid-containing feed.

Folic acid is also effective in promoting growth in aquatic animals. Molokhiya, which contains a large amount of folic acid, is cultivated in the vicinity of the culture pond, and the molokhiya, in which the main axis has grown, is put into the culture pond. The area around the molokheiya becomes a resting place for juvenile shrimps, and the folic acid leached out there is absorbed by the juvenile shrimps, which helps promote the growth of the juvenile shrimps. Since folic acid is mainly found in the leaves of Molokhiya, it is better to remove the seeds, fruits and flowers before putting them into the aquaculture pond.

The size of phytoplankton and zooplankton is variable and usually ranges from 0.2 μm to 2000 μm. 0.2 μm plankton floats, while 2000 μm plankton settles and deposits on the bottom. It is preferable to install a circulation pump at the bottom of the pond for flotation and algal dissolution of plankton at the bottom. When a pump installed at the bottom creates an upward flow from the bottom to the surface of the liquid, circulation in the tank becomes active and there is no stationary part in the tank.

In order not to give environmental stress to aquatic animals in post-larva tanks and aquaculture ponds, create a stable living environment without deterioration of water quality and temperature, and sudden changes in pH, dissolved oxygen concentration, plankton concentration, salt concentration, water temperature, etc. is desirable. For this reason, it is recommended to provide a regulating pond to absorb fluctuations in water quality, such as seawater supplied to the post-larva tank and the aquaculture pond.

The amount of make-up water from the regulating pond to the post-larva tank and the aquaculture pond is sufficient to compensate for the amount of evaporation and leakage. With this level of replenishment, it is possible to avoid major changes in the environment of the pond.

The method of inputting humic substances into aquaculture ponds is direct input of humic powders or humus pellet-filled nets as in the post-larva tank, and/or circulating supply of humus-containing water from a humus bioreactor attached near the aquaculture ponds. . Generally, in a culture pond having a large volume exceeding 1000 m ³ , it is preferable to install a humus bioreactor in order to purify the pond water, adjust the supply of microorganisms, maintain the effect of humic substances, and the like. The humus bioreactor is charged with humic substances in the form of dust or pellets and refreshed from time to time.

In the humus bioreactor, proliferated microorganisms prey on and decompose organic matter in the circulating water. The circulating water, in which organic matter is decomposed and contains humic substances, algalytic microorganisms, and other microorganisms, is returned to the aquaculture pond.

In the aquaculture method of the present invention, the input amount of humic substances depends on the growth period of aquatic animals (larval stage, juvenile stage), the type and scale of the breeding facility (post larva tank, aquaculture pond, etc.), the environment of the feed (phytoplankton, zooplankton, feed, etc.), it is determined to adjust the plankton concentration in the farm, reduce BOD, and adjust the pH.

Plankton concentration and pH in aquaculture ponds vary with solar radiation dose. In the present invention, by adjusting the amount of humic substances and microorganisms supplied from a humus bioreactor or the like, the amount of microbial growth, plankton concentration, pH, etc. in a farm can be managed appropriately and stably. For example, when the sun's rays are strong, the plankton concentration in the pond is high, algae are growing, and the pH is also rising, the flow of circulating water containing humic substances and microorganisms from the humic bioreactor is enhanced. When the sunlight is weak and the algae growth rate is slow, the supply of circulating water from the humus bioreactor is temporarily stopped or changed to intermittent operation to reduce the amount of dissolved algae, thereby maintaining an appropriate plankton concentration.

Phytoplankton concentration, pH and BOD can be measured by conventional methods. Appropriate water quality for the growth of juvenile shrimp with no environmental stress due to proper phytoplankton concentration and pH can be evaluated by observing the color of the pond. Transparent blue water quality has no water pollution but no nutrients. Opaque yellow-brown water quality indicates the presence of plankton and suitability for aquaculture ponds.

There is a desire to increase the stocking density of aquatic animal farms in order to increase the yield of adult aquatic animals. Increasing stocking density in conventional aquaculture methods resulted in higher mortality rates and did not lead to increased yields. For example, in conventional shrimp farming methods, the maximum breeding density is 100 fish/m ² . Under favorable environmental conditions, aquatic animals grow regardless of body size, but under harsh environmental conditions, only a few large individuals tend to survive.

The aquaculture method of the present invention allows for increased stocking density in aquatic animal farms through overall improvement of environmental, spoilage and infection stress. For example, in the case of shrimp breeding, the breeding density is usually increased to 100 fish/m ² or more, preferably 150 fish/m ² or more, particularly preferably 200 fish/m ² or more, and further preferably 200 to 300 fish/m ² . However, a high yield (for example, 90%) can be maintained.

The present invention will be described in more detail below by showing Examples. However, the invention is not limited to the examples.
[Example 1] Shrimp farming test A farm 1 shown in Fig. 1 was established in the suburbs of Ho Chi Minh City, Vietnam, and vannamei shrimp were bred for three months. The farm 1 was basically divided into a post lava tank 20 for cultivating juvenile shrimps to juvenile shrimps and a farming pond 30 for cultivating juvenile shrimps to adult shrimps. Shrimp up to 13 days after hatching are called larvae shrimp, and shrimps that are transferred from the postlarva tank to the culture pond after 13 to 20 days are called postlarva shrimp, and are transferred to the culture pond and cultivated. Shrimp that are juvenile are called juvenile shrimp.

The specifications of the farm 1 shown in Figure 1 are shown below.
[1] Reservoir 10
Dimensions 40m width x 100m length x water depth 1.0-1.5m x 1 pond Volume 5000m ³
[2] Post rubber tank 20
Dimensions 13mφ x 1.3m height x 1.0m water depth x 1 tank Volume 130m ³
Blower 2 m ³ /min × 20 kPa × 1.5 kw × 1 unit Humus materials (1) Spray 180 kg of humus powder (product name EZ-70, Enzyme Co., Ltd.) (2) Humus pellets (product name EZ-201, Enzyme Co., Ltd.) A set of 60 kg filling net (manufactured by the company) was suspended. A net (not shown) was also provided on the top of the post-larva tank to protect the tank from birds and the like while keeping the inside of the tank bright.
[3] Aquaculture Pond 30
Dimensions 64m width x 100m length x water depth 1.0-1.5m x 1 pond Capacity 8000m ³
Circulation pump (submersible pump) 150φ x 2m ³ /min x 6m x 5.5kw x 1 unit Aeration Surface aerator (1.5kw) x 4 units and blower x 1 unit 70, manufactured by Enzyme Co., Ltd.) (2) 120 kg of humus pellets (product name EZ-201, manufactured by Enzyme Co., Ltd.) suspended as a set [4] Humus bioreactor 40
Dimensions 2300 mmφ x 3000 mm height x 1 tank Volume 10 m ³
Blower 25φ×0.3m ³ /min×50kPa×0.75kw×1 unit Humus material
(1) Sprinkle 30 kg of humic powder (product name: EZ-70, manufactured by Enzyme Co., Ltd.) (2) Suspend a set of 180 kg of humus pellets (product name: EZ-201, manufactured by Enzyme Co., Ltd.)

Tables 3 and 4 show the component tables of the humic dust agent EZ-70 and the humus pellet EZ-201 used, respectively.

1. Aquaculture test of larval shrimp in the post-larva tank Fresh seawater received from the sea in the regulating pond 10 is retained for 7 to 10 days, the salt concentration, pH, etc. are measured and adjusted, and sand, contaminants, suspended matter, etc. are removed naturally. precipitated. The adjusted seawater was sent to the post lava tank 20 through a pipe.

The humus powder was dispersed in the post larver tank 20, and a humus pellet-filled net 22 was suspended. The post lava tank 20 is designed to aerate seawater with a blower 21 . In the post-larva tank 20, phytoplankton such as diatoms grew moderately due to sunlight in the presence of humic substances, and organic matter in the tank was decomposed by the humic substances, resulting in an opaque yellow-brown color inside the tank. . The pH in the bath remained stable between 7.0 and 8.3 during the test period.

The phytoplankton and microorganisms were fed to the larval shrimp. The multiplied microorganisms not only served as food, but also purified the exuviae, shrimp feces, food leftovers, algae, etc. generated in the tank. We were able to suppress plankton algae growth, purify other causes of water quality deterioration such as shrimp droppings, and promote healthy growth of shrimp.

About 1,200,000 larval shrimp were placed in the post-larva tank 20 and grown for about 20 days. By this aquaculture, the larval shrimp molted and grew to the point of being able to swim, with a height of 2-3 cm and a weight of about 0.5 g. Favorable rearing data of 98% growth yield of larval shrimp in the post-larva tank was obtained (Table 5).

2. Cultivation of Juvenile Shrimp in an Aquaculture Pond The humus bioreactor 40 was sprayed with the humus powder, and a humus pellet-filled net 42 was suspended. Fresh seawater received from the sea in the regulating pond 10 was held for 7 to 10 days, the salinity, pH and the like were measured and adjusted, and sand, contaminants, floating matter and the like were allowed to settle naturally. The conditioned seawater was piped to the culture pond 30 and the humus bioreactor 40 . The humus bioreactor 40 and the aquaculture pond 30 were communicated with each other through a pipe, and seawater was circulated between the humus bioreactor 40 and the aquaculture pond 30 by a circulation pump 31 . Aquaculture pond 30 and humus bioreactor 40 are adapted to aerate seawater by blowers 33 and 41, respectively.

Circulating water received in the humus bioreactor 40 from the culture pond 30 through the circulation pump 31 was organically decomposed by humic substances and microorganisms in the humus bioreactor and purified. The purified circulating water was returned to the culture pond 30 while containing humic substances and microorganisms.

In the aquaculture pond 30, phytoplankton such as diatoms grew moderately due to sunlight in the presence of humic substances, and organic matter in the pond was decomposed by the humic substances. As a result, the inside of the tank exhibited an opaque yellowish brown color. During the test period, the pH in the pond was stable at 7.0-8.3.

Conventionally, raising the breeding density of juvenile shrimp in aquaculture ponds was stressful. In conventional aquaculture methods, a breeding density not exceeding 100 fish per ^square meter was a well-known management. In the present invention, 1,180,000 fish were released into an aquaculture pond of 8,000 m ³ , and a breeding density of 148 fish/m ² was made possible. Favorable rearing data of 90% yield rate of living shrimp in the pond at the above rearing density was obtained (Table 5). The average weight of shrimp grown in 3 months of farming was 25 g. 1,180,000 tails×0.90×25×10 ⁻³ kg/tail≈26,500 kg was harvested. This improvement in yield and yield is due to the prevention of deterioration of water quality due to suppression of algae growth by phytoplankton and other deterioration of water quality such as shrimp excrement, thereby promoting healthy growth of shrimp.

1 aquaculture farm 10 regulating pond 20 post larva tank 21 blower 22 humus pellet filling net 30 culture pond 31 circulation pump 32 surface aerator 33 blower 40 humus bioreactor 41 blower 42 humus pellet filling net GL Ground line
WL Water line

Claims (7)

1. A method of cultivating an aquatic animal farm, comprising culturing said aquatic animal in the presence of a humic substance;
The humic substance grows algalytic microorganisms,
The aquaculture method, wherein the plankton concentration in the aquaculture farm is adjusted and the BOD is reduced by adjusting the input amount of the humic substance. The aquaculture method according to claim 1, wherein the humic substance for growing algalytic microorganisms is obtained by lightening humus soil at a moisture content of 50 to 80%. 3. The aquaculture method according to claim 1 or 2, wherein the aquaculture improves the growth yield in the larval stage. The aquaculture method according to claim 3, wherein the aquaculture farm is a post-larva tank for larvae. 3. The aquaculture method according to claim 1 or 2, wherein the aquaculture increases the rearing density of juvenile fish. 6. The aquaculture method according to claim 5, wherein the farm is a fry pond. The aquaculture method according to any one of claims 1 to 6, wherein the aquatic animals are crustaceans.

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