JP3427002B2 - Fish culture method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cultivating fish and shellfish using macroalgae, and more particularly to a method and an apparatus for cultivating fish and shellfish that enables purification of aquaculture areas.

[0002]

2. Description of the Related Art Conventionally, fish farming in coastal waters has been
It is carried out by feeding raw food that is partially cut sardines, crushed into minced form, or mixed feed mixed with fish powder such as sardines to the sea surface in the cage of farmed fish several times a day. It was

The conventional aquaculture method as described above has the following problems. (1) When supplying raw fish such as sardines as a bait to cultured fish, it is known that about 1/3 of the supplied bait passes through the bottom and side surfaces of the cage and sinks as a residue on the seabed. At this time, the residue was decomposed due to the slow decomposition by bacteria on the seabed, which resulted in pollution of the culture area.

In addition, floating food residues cause red tides due to excessive accumulation of nitrogen and phosphorus.
In the aquaculture densely populated area, it was a serious problem that wiped out aquaculture.

(2) When a mixed feed is used, the amount of farmed fish left behind is greater than that of raw feed, and the amount of residue settling on the seabed is small, but settling on the seabed is unavoidable and expensive. For this reason, it has spread to only some high-grade aquaculture fish and is not established as a general-purpose purification method for aquaculture waters.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above problems and to easily and efficiently remove the residuals of cultured fish feed and organic nitrogen and phosphorus contained in the excrement of cultured fish. It is an object of the present invention to provide a method and an apparatus for cultivating seafood having a seawater purification function, which can be removed from a fish farm.

[0007]

In order to solve the above-mentioned problems, the present invention cultivates seafood in a breeding area, and fixes the food residue and / or excrement of the farmed fish in the breeding area in the breeding area. It is decomposed by a bacterium that has been decomposed, and in the culture region adjacent to the breeding region, by absorbing the decomposed product into macroalgae as a nutrient, the macroalgae is proliferated, thereby purifying the breeding region and the culture region. A method for cultivating seafood is provided.

[0008] The present invention also relates to a cultured fish breeding means for breeding cultured fish, a feeding means for feeding the cultured fish to the cultured fish, and a feeding bacteria arranged in the cultured fish breeding means for fixing the food. Residues and / or bacteria adhering / proliferating means for decomposing excrement of the seafood and growing bacteria, and adjoining the cultured fish breeding means, for accommodating macroalgae, and containing the food residue and / or Provided is a fish and shellfish aquaculture device comprising a macroalgae culturing means for culturing macroalgae by allowing the macroalgae to absorb the decomposed products of the fishery products as nutrients.

In the above-described method and apparatus for cultivating fish and shellfish of the present invention, sterile seaweed, particularly sterile sea lettuce, can be preferably used as the macroalgae used.

Bacteria are fixed to the bottom and / or sides of the breeding area and decompose the food residues and / or seafood excrement that float or settle in the breeding area, and the degradation products are nutrients. As a result, the macroalgae can be absorbed, and thereby the macroalgae can be cultured.

Macroalgae grown by using the above-mentioned decomposed products as nutrients can be recovered from the culture area, cut, and supplied to the breeding area as bait for fish and shellfish. By doing so, it is possible to purify the aquaculture area and perform aquaculture at low cost.

It is also possible to collect the proliferated macroalgae from the culture area, cut them, and recycle them to the culture area. By doing so, it is possible to combine the purification of the aquaculture area with a closed system, and it is highly efficient. It becomes possible to cultivate seafood.

In the aquaculture device of the present invention, the aquaculture fish breeding means may be a breeding tank having an inclined bottom surface, and a rope-shaped body as a means for attaching and multiplying bacteria may be attached to the bottom surface and / or side surface of the breeding tank. I can. Bacteria that originally existed in the breeding tank adhere to the rope, or bacteria can be separately attached before the rope is installed.

The means for culturing macroalgae can be arranged in a part of the breeding tank partitioned by a net-like member, and
It may be provided with a stirring means and / or an air supply means.

According to the present invention configured as described above,
A low environmental load type with seawater purification function by combining seafood breeding, bacterial culture, and culture of marine macroalgae that can grow all year round, such as sterile sea lettuce. Can provide a farmed fish production system.

The present inventors have searched for a large algae that can grow in seawater throughout the year without changing generations and can absorb nitrogen, phosphorus, etc., in order to realize a system for producing cultured fish having a seawater purification function. As a result, it was found that sea urchin was collected from Kagoshima Bay, and that this strain had the property of being able to be cultivated all year round by examining the culture conditions, and this strain was sterilized Mio-AT.
It was named RC-1 strain. This strain can be particularly preferably used in the present invention.

The characteristics of this strain are as follows. Shape: Cloth-like floating size: 1 cm to 1 m size can grow. Motility: None Nitrogen source: Ammonia nitrogen, urea nitrogen, nitrate nitrogen can grow. Photosynthetic pigments: chlorophyll a, chlorophyll b. , Carotenoid (detected by thin-layer chromatography) Proliferative ability: Irradiation with fluorescent light in seawater medium shown in Table 1 described later 1
Approximately 0.3 g (dry weight / liter · day) under conditions of 5,000 lux and 25 ° C.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a fish farming production system according to an embodiment of the present invention, in which (a) is a top view,
(B) is a side view. The fish farming system shown in FIG. 1 comprises a farmed fish breeding means 1 in which farmed fish grows, a feeding means 2 for feeding bait to the farmed fish, a bacteria attachment / proliferation means 3 for bacteria to easily attach and multiply, And a macroalgae culture means 4 for culturing macroalgae that absorbs the decomposition products of bacteria.

Among these means, the cultured fish breeding means 1
Consists of a cage that has a structure that allows seawater to pass through the sides and bottom, and its outer circumference has various shapes.For example, some farmed fish can be octagonal or circular to prevent side collision. is there. The feeding means 2 may be a device capable of supplying a constant required amount at a constant time, but in some cases, it may be substituted by being supplied by a person.

The bacteria adhering / propagating means 3 is provided at the bottom of the cultured fish breeding means 1, and the material thereof is a simple cloth-like material so that bacteria that decompose food residues and excrements of the cultured fish adhere and propagate easily. However, a structure having a three-dimensional thickness and a large surface area is preferable. As an example, a rope-shaped object made of nylon or cotton is effective.

Bacteria in seawater are
The breeding means 3 attaches to the bottom of the cultured fish breeding means 1, that is, the bottom of the cage. The residue of the bait and the excrement of the cultured fish that have fallen into the cage are settled on the bottom of the cage.
It is decomposed by the bacteria fixed to and is easily converted into various dissolved nitrogen such as urea, ammonia, nitrous acid, and nitric acid.

In order to attach and multiply microorganisms (bacteria) to the rope-shaped material constituting the bacteria attachment / proliferation means 3, the rope-shaped material is shown in the following Table 1 before being placed in the ocean. It is desirable to preliminarily increase the adherent bacteria by immersing in the medium. When this bacterium attachment operation is performed under aeration, the bacterium growth is promoted, and the bacterium can be attached to the rope-shaped material in a short time.

[0023] Table 1 marine bacterial adhesion promoting medium polypeptone 0.25g Yeast Extract 0.25g FeSO ₄ · _7H 2 O Further 0.01g _Na 2 _HPO 4 0.01g seawater 250ml tap water 750 ml pH 7.8, the adhesion of bacteria If it is necessary to further accelerate the, to the above-mentioned medium, bacteria such as Micrococcus halobius, Halococcus morrhuae having salt resistance and protein degradability are supplied as seeds, and these bacteria are preferentially supplied.
And it can be attached quickly.

When the speed of bacterial adhesion is not required, the speed-up method described above is not adopted, and the cultured fish breeding means 1 is used.
It is also possible to utilize the bacteria that naturally occur in the food residue and the excrement of cultured fish that are put inside.

The bottom of the cage is inclined, and the angle of inclination is 1 to 20 degrees, preferably 5 to 10 degrees. By inclining the bottom surface in this way, the sedimented food residue undergoes decomposition by bacteria on the bottom surface,
It can move toward the macroalgal culture means 3 described later.

At one corner of the cultured fish breeding means 1, a large algae culturing means 4 is installed. This macroalgal culture means 4
Is equipped with a paddle type stirring device 5. This paddle type stirring device 5 supplies air to the macroalgae housed in the macroalgal culture means 4 to promote the growth of macroalgae by CO ₂ in the air, and the side surface and the bottom surface of the cultured fish breeding means 1. Air is supplied to the bacteria attached to the
It is provided in order to promote the decomposition of the residue by ₂ .

In order to further accelerate the decomposition of the residue, the aeration supply port 6 is provided at the bottom of the large algae culture means 4.
With the air supply device 7 provided with, the residue is decomposed and
It is possible to promote the growth of macroalgae, thereby making it possible to more efficiently absorb the decomposition products N and P.

The main body of the macroalgae culture means 4 prevents contact between the cultured fish and the macroalgae, and the cultured fish has the macroalgae culture means 4
It has a structure partitioned by a partition net 8 so as not to enter inside. Further, in the case of a fish species that does not feel stress due to operations such as stirring for supplying air during macroalgal culture, the pore size of the partition net 8 is increased so that cultured fish can enter the macroalgal culture means 4. It is also possible to use the macroalgae as a bait for farmed fish.

According to such a macroalgal culture means 4,
Large algae is made from sunlight and CO ₂ as raw materials, and means for raising cultured fish 1
It can absorb dissolved nitrogen such as nitric acid and phosphorus existing in the seawater inside it and grow efficiently, thereby positively fixing nitrogen and phosphorus in seawater by macroalgae.
It can be removed.

Large algae such as sea lettuce grown by absorbing dissolved nitrogen and phosphorus can be easily collected by a human hand with a net or the like. By installing the paddle of, it is possible to easily collect with labor saving.

The large algae used in the aquaculture fish production system of the present invention as described above include, as well as sterile sea lettuce, Honda straw and hornwort.

[0032]

EXAMPLES Examples of the present invention will be shown below to more specifically describe the present invention. Example 1 In this example, the following experiment was conducted on the size of Ulva used in the aquaculture fish production system of the present invention, and the size suitable for use was determined. When the size of the sea lion used is 1 m square, empirically, it is easy to bend in the floating state,
The light receiving efficiency of the sunlight necessary for multiplication will be reduced. In addition, when a physical stimulus due to stirring is applied, the sea lettuce is likely to be cut, and the cut surface of the cut sea lettuce becomes scratched,
It is likely to become a factor that hinders the growth of Aosa.

Then, when 1 m square and 1000 cm square sea water were stirred for 1 hour in agitated seawater, the 1 m square individual was cut into 3 individuals, but the 15 cm square individual was not cut. Was able to hold the size of.

From the above results, it is preferable that the size of the sea lion used in the cultured fish production system of the present invention is 3 cm.
˜50 cm, more preferably 5 cm to 30 cm.
By controlling the size like this, along with the efficiency of receiving sunlight, the mechanical strength of the sea lettuce increases, it becomes difficult for it to be cut by physical stimulation such as stirring, the scratches due to cutting decrease, and the growth rate improves. You can contribute.

As a cutting method for the sea lion, a method using punching having a sharp blade can be adopted.
According to this method, the area of the scratches on the sea lions during cutting is reduced, the time required for repairing the scratches can be reduced, and the proliferation can be improved. However, when a non-sharp blade is used, the cutting surface of the sea lettuce becomes large, the time required for repairing the wound increases, and the proliferation rate decreases.

Example 2 The following operation was carried out in order to attach marine bacteria to a cotton rope-shaped material as the bacterial attachment / proliferation means 3. That is, the marine bacterial adhesion-promoting culture solution (100 ml) shown in Table 1 above was allowed to stand at room temperature,
The culture was performed under different conditions under aerobic conditions by shaking (60 rpm) as a substitute for paddle stirring. As a bacterium to be used, Micrococcus halobius having a protein degrading property was used.

As a result, when the bacterial attachment operation was carried out under aerobic conditions, the bacterial growth was promoted.
After 8 hours, the turbidity OD _{610 of the} culture solution increased 10 times as compared with the static state. This shows that under aerobic conditions, the target bacteria can grow in a shorter time.

Next, a sterilized nylon rope-shaped material (1 cmΦ, 1 cm length) was immersed in this culture solution for 24 hours to attach bacteria. In order to confirm the adherence of bacteria by this operation, the rope adhered with bacteria was immersed in 40 (v / v)% perchloric acid at 60 ° C for 2 hours, and the supernatant was neutralized with NaOH solution. The protein concentration was measured.

As a result, 1 mg / ml of protein derived from bacteria was detected. Thereby, it was confirmed that the target bacteria could be rapidly attached to the rope-shaped material by these operations. In this way, the bacteria capable of degrading the protein, which is the main component of the food residue, can be provided to the bacteria attachment / proliferation means 3, thereby containing N and P derived from the food residue and the excrement of the cultured fish. It has become possible to decompose the compound into a low molecular weight compound.

Sterile sea lettuce MHI-ATRC-1 strain was mixed with sterile seawater by mixing three kinds of media having different nitrogen forms shown in Table 2 below,
It was used as a culture medium under bright conditions. 1 L of this culture,
Put the above-mentioned cultivated species of sterile sea lettuce MHI-ATRC-1 (0.2g as dried algae) in a flat transparent container, continuously irradiate about 15,000 lux with a white fluorescent lamp, and aerate the air. Meanwhile, the cells were cultured at 25 ° C for 7 days.

Table 2 Medium composition A NH ₄ Cl 12 ppm-N Sodium dihydrogen phosphate 1.2 ppm-P B Urea 12 ppm-N Sodium dihydrogen phosphate 1.2 ppm-P C NaNO ₃ 12 ppm-N Sodium dihydrogen phosphate 1.2 ppm-P As a result, as shown in FIG. 2, the weight of the sea lettuce doubled in 7 days, and about 0.5 g (as dried algae) of algal cells could be obtained in 1 L. As described above, it is experimentally found that the different forms of nitrogen sources generated by the decomposition products of organic matter are absorbed by the sea lettuce and can be multiplied thereby, and the different forms of nitrogen in seawater can be fixed and recovered by the sea lettuce. Turned out.

Furthermore, using sterile seawater having a dissolved nitrogen concentration of about 1 ppm obtained from the vicinity of Hakkeijima, Kanazawa-ku, Yokohama-shi, which is as high as dissolved water nitrogen, the sterile Aosa MHI-ATRC-1 strain was exposed to natural light. Cultured. The culture was performed by the following procedure.

In a culture tank (0.3 mΦ × 0.5 m height),
Air alone and a gas obtained by adding 0.5% CO ₂ to the air were supplied at a rate of 0.1 L / sea water volume L · min, and sea water was supplied three times a day to supply dissolved nitrogen to sea lettuce. I replaced it. In addition, after the sea lettuce was prepared with a leaf punch to a size of 4 cm in diameter, this sea lettuce 1000 solid was added to a culture tank and cultured for 2 weeks.

As a result of obtaining the growth rate in this culture,
As shown in FIG. 3, 18 g under the condition of adding CO _2.
(Dry weight) / m ² · day, 7g / in air alone
It was confirmed that each of them grew in m ² · day. On the other hand, when the algal bodies were collected and the nitrogen and phosphorus contents were measured, they were 3% and 0.2%, respectively, based on the dry weight.

From these results, it is found that, under the condition of adding CO ₂ , 0.6 g nitrogen / m ^{2 ·} day speed and 0.04 g
Phosphorus / m ² · day rate, with air alone added 0.23 g nitrogen / m ² · day rate and 0.015 g phosphorus /
It was found to absorb nitrogen and phosphorus at a rate of m ² · day, respectively.

As described above, the sterile sea lettuce is capable of absorbing and growing any of N sources such as nitrate nitrogen, urea and ammonia in seawater and phosphorus, and by using this seaweed, seawater is used. It is possible to immobilize various forms of N and P, which are decomposed products such as food residues and excrement of cultured fish contained therein. Therefore, by recovering such sea lettuce, it is possible to effectively purify seawater in the cultured fish production system.

[0047]

INDUSTRIAL APPLICABILITY As described above in detail, according to the present invention, large amounts of algae fix nitrogen and phosphorus derived from food residue and excrement of cultured seafood in the culture of seafood. As a result, the aquaculture area can be purified throughout the year, and an environment-friendly aquaculture fish production system can be provided. In addition, the propagated macroalgae can also be used as diversified biomass resources, such as being collected and reused as feed for cultured fish or feed for poultry, which has secondary effects.

[Brief description of drawings]

FIG. 1 is a diagram showing a fish farming production system according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the number of days of culture and the weight change of Ulva.

FIG. 3 is a characteristic diagram showing a comparison of the growth rate of Ulva in the case of adding CO ₂ and the case of adding only air.

[Explanation of symbols]

1 ... Cultured fish breeding means 2 ... Feeding means 3 ... Bacteria attachment / proliferation means 4 ... Macroalgal culture means 5 ... Stirrer 6 ... Aeration supply port 7 ... Air supply device 8 ... Partition net

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-2-242629 (JP, A) JP-A-2-222624 (JP, A) JP-A-10-42747 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A01K 63/04 A01G 33/00 A01K 63/00

Claims (12)

(57) [Claims] 1. A seafood is cultivated in the breeding area, and the food residue and / or excrement of the cultivated fish in the breeding area is decomposed by the bacteria fixed in the breeding area,
In the culture area adjacent to the breeding area, by adsorbing the decomposed product to macroalgae as a nutrient, the macroalgae is proliferated, thereby purifying the breeding area and the culture area, thereby cultivating fish and shellfish. . 2. The method for cultivating fish and shellfish according to claim 1, wherein the macroalgae is sterile sea lettuce. 3. The method for cultivating seafood according to claim 1, wherein the bacteria are fixed to the bottom and / or side of the breeding area. 4. The method according to claim 1, wherein the propagated macroalgae are collected from the culture area, cut, and supplied to the breeding area as a bait for the seafood. Method for aquaculture of seafood. 5. The method for cultivating seafood according to any one of claims 1 to 4, wherein the grown macroalgae are recovered from the culture area, cut and recycled to the culture area. . 6. A cultured fish raising means for raising cultured fish, a feeding means for feeding the cultured fish with feed, and a residue of the food and / or a residue of the feed arranged and fixed in the cultured fish raising means. Bacteria attachment / proliferation means for decomposing the excretions of the seafood and multiplying bacteria, arranged adjacent to the cultured fish breeding means, accommodating macroalgae, leaving the food residue and / or the seafood An apparatus for cultivating fish and seafood, comprising a macroalgae culturing means for culturing macroalgae by allowing the macroalgae to absorb excretion decomposition products as nutrients. 7. The cultured fish breeding means is a breeding tank having an inclined bottom surface, and a rope-shaped body as the bacteria adhering / growing means is attached to the bottom surface and / or side surface of the breeding tank. The aquaculture device for seafood according to claim 6, wherein. 8. The aquaculture device for seafood according to claim 7, wherein the large-scale algae culturing means is arranged in a part of the breeding tank partitioned by a net-shaped member. 9. The aquaculture device for seafood according to any one of claims 6 to 8, wherein the macroalgal culture means is provided with a stirring means. 10. The aquaculture device for seafood according to claim 6, wherein the large algae culturing means is provided with an air supply means. 11. The method according to claim 6, further comprising means for recovering the grown macroalgae from the culture area and supplying the macroalgae as food for the seafood to the breeding area. The aquaculture device for seafood according to item 1. 12. The method according to claim 6, further comprising means for collecting the grown macroalgae from the culture area, cutting them, and recycling them to the culture area.
The aquaculture device for seafood according to any one of 1.