JP7336226B2 - Shellfish farming method - Google Patents

Description

The present invention relates to a shellfish farming method.

Various methods are known for cultivating shellfish such as oysters.
For example, Patent Literature 1 discloses a method that has a peripheral wall and a bottom wall, prevents food supplied from the sea surface and supplied into the tank from flowing out of the tank, and at least the peripheral wall has a predetermined ratio of bait to the tank. An aquaculture tank having a seawater exchange window opening for exchanging seawater inside the tank with seawater outside the tank, mooring means for suspending the aquaculture tank from the sea surface, feeding means for supplying feed into the aquaculture tank, and A bivalve aquaculture system characterized by comprising seawater fluidization means for fluidizing seawater in the aquaculture tank and shellfish holding means for holding bivalves requiring aquaculture in the aquaculture tank is described.
Further, Patent Document 2 describes an oyster or scallop aquaculture method characterized by installing a fertilizing container containing fertilizer in a hanging farm.

Japanese Unexamined Patent Application Publication No. 2000-300107 JP 2011-115183 A

An object of the present invention is to provide a method for cultivating shellfish that can promote the growth of shellfish.

As a result of intensive studies to solve the above problems, the present inventors have found that a step of culturing algae and a step of supplying the cultured algae into aquaculture water containing shellfish and a calcium silicate-containing material. And, according to the shellfish farming method including the step of farming the shellfish in the water for farming, it was found that the above object can be achieved, and the present invention was completed.
That is, the present invention provides the following [1] to [5].
[1] An algae culture step of accommodating algae in culture water for culturing algae and culturing the algae; and an algae supply step of supplying the calcium silicate-containing material into aquaculture water containing the material; A method for cultivating shellfish, characterized by including a step.
[2] The method for culturing shellfish according to [1] above, wherein the culturing of the shellfish is carried out while pouring the water for culturing.
[3] The method for cultivating shellfish according to [1] or [2], wherein the shellfish are cultured above the calcium silicate-containing material and not in contact with the calcium silicate-containing material.
[4] An algae culture tank for culturing algae, an algae cultured in the algae culture tank, shellfish, a calcium silicate-containing material, and aquaculture water are housed to culture the shellfish. and a pipeline for supplying the algae from the algae culture tank to the shellfish culture tank.
[5] The shellfish farming system according to [4] above, wherein the shellfish farming tank has, above the bottom surface thereof, a shelf for placing the shellfish thereon.

According to the method for cultivating shellfish of the present invention, the growth of shellfish can be promoted, and the cultivation period until shipment can be shortened.

1 is an example of a shellfish-cultivating tank in the shellfish-cultivating system of the present invention, and is a cross-sectional view showing a state in which the shellfish-cultivating tank is cut in the vertical direction. FIG.

The method for cultivating shellfish of the present invention includes an algae culturing step of accommodating algae in culture water for culturing algae and culturing the algae, and culturing the algae cultured in the step. and a shellfish aquaculture step of cultivating the shellfish in the aquaculture water containing the shellfish and the calcium silicate-containing material. includes.
Each step will be described in detail below.

[Algae culture process]
This step is a step of accommodating algae in culture water for culturing algae and culturing the algae.
The algae are not particularly limited as long as they can be eaten as bait by cultured shellfish, and examples thereof include diatoms.
For algae, from the viewpoint that a sufficient amount of algae can be secured and the supply amount can be easily adjusted, algae are cultured separately from the water for aquaculture containing shellfish (described later). cultured in culture water for Incidentally, the water for cultivation is usually the same as the water for cultivation (fresh water, brackish water or sea water). Moreover, you may add another component as needed.
Examples of other ingredients include nutrients such as vitamins such as vitamin B12, biotin, and thiamine. Also, examples of known compositions containing other ingredients include KW21, f/2, BBM, CSi, Chu-No. 10, NN-1, WC, PES and the like (basal medium).
In addition, from the viewpoint of promoting the growth of algae, the algae may be cultured after supplying a calcium silicate-containing material (described later) into the culture water.
The amount of the calcium silicate-containing material supplied to the culture water for culturing algae is preferably 0.01 to 30 g/liter, more preferably 1 to 20 g/liter, and particularly preferably 3 to 15 g. / liter.

[Algae supply process]
This step is a step of supplying the algae cultured in the previous step into water for cultivation containing the shellfish to be cultivated and the calcium silicate-containing material.
Algae are typically fed into the culture water along with the culture water.
[Shellfish farming process]
This step is a step of cultivating shellfish in water for cultivating algae supplied in the previous step.
Shellfish to be cultivated are not particularly limited, and examples thereof include bivalves such as oysters, clams, clams, corbiculas, and surf clams, and snails such as abalones, turban shells, and Uminina.
Freshwater, brackish water or seawater can be used as the water for aquaculture according to the shellfish to be cultivated.

Examples of calcium silicate-containing materials that may be used in the present invention include tobermorite, xonotlite, CSH gel, foshagite, gyrolite, hillebrandite, wollastonite, and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.
Tobermorite is a crystalline calcium silicate hydrate, Ca5 _. ( _{Si6O18H2 ) .4H2O} ( _platy morphology ₎ , Ca5 _. ( _{Si6O18H2 )} ( It has a chemical composition of Ca ₅ · (Si ₆ O ₁₈ H ₂ ) · 8H ₂ O (fibrous form).
Xonotlite is a crystalline calcium silicate hydrate and has a chemical composition such as Ca ₆ ·(Si ₆ O ₁₇ ) ·(OH) ₂ (fibrous form).
CSH gel has a chemical composition of αCaO.βSiO ₂ .γH ₂ O (where α/β=0.7 to 2.3 and γ/β=1.2 to 2.7). be. Specifically, calcium silicate hydrate having a chemical composition of 3CaO.2SiO ₂ .3H ₂ O and the like can be mentioned.
Foshagite has a chemical composition such as Ca ₄ (SiO ₃ ) ₃ (OH) ₂ .
Gyrolite has _a chemical composition such as ( _NaCa2 ) _Ca14 ( _Si23Al ) _O60 (OH) _8.14H2O .
Hillebrandite has a chemical composition such as Ca ₂ SiO ₃ (OH) ₂ .
Wollastonite has a chemical composition such as CaO.SiO ₂ (fibrous or columnar).

The calcium silicate-containing material is preferably a granule (powder or granular) from the viewpoint of increasing the elution amount of silicic acid and calcium contained in the material. The particle size of the calcium silicate-containing material is preferably 6 mm or less, more preferably 5 mm or less, particularly preferably 4.5 mm or less, from the viewpoint of increasing the elution amount of silicic acid and calcium. The lower limit of the particle size is preferably 0.001 mm, more preferably 0.005 mm, particularly preferably 0.01 mm, from the viewpoint of reducing the energy required for pulverization.
From the viewpoint of increasing the elution amount of silicic acid and calcium, the particle size distribution of the calcium silicate-containing material preferably contains a material having a particle size of 6 mm or less at a rate of 70% by mass or more, more preferably 5 mm. It contains 70 mass % or more of a material having the following particle size, and particularly preferably contains 70 mass % or more of a material having a particle size of 4.5 mm or less.
In addition, if the amount of silicic acid and calcium eluted from the calcium silicate-containing material increases, the growth of shellfish is further promoted.

The content of soluble silicic acid in the calcium silicate-containing material is preferably 10% by mass or more, more preferably 15% by mass or more, from the viewpoint of eluting a sufficient amount of silicic acid for shell formation and diatom growth. Particularly preferably, it is 17% by mass or more. The upper limit of the content is not particularly limited, but is usually 50% by mass from the viewpoint of availability.
The content of soluble lime in the calcium silicate-containing material is preferably 10% by mass or more, more preferably 12% by mass or more, particularly preferably 12% by mass or more, from the viewpoint of eluting a sufficient amount of calcium for shell formation and diatom growth. is 17% by mass or more. The upper limit of the content is not particularly limited, but is usually 39% by mass from the viewpoint of availability and the like.

Each content of soluble silicic acid and soluble lime is the mass ratio of soluble components (silicic acid or lime) dissolved in 0.5 mol / liter hydrochloric acid aqueous solution (liquid temperature: 30 ° C.), Independent administrative agency Agriculture, Forestry and Fisheries It can be measured in accordance with the "fertilizer test method (2018)" supervised by the Food Safety Technology Center (FAMIC).

The amount of calcium silicate-containing material contained in aquaculture water varies depending on the type of shellfish, the number of individuals, the size of each solid, and the amount of silicic acid and calcium eluted from the calcium silicate-containing material, but is preferable. is 0.01 g/liter or more, more preferably 1 g/liter or more, and particularly preferably 3 g/liter or more. If the amount is 0.01 g/liter or more, the growth of shellfish can be promoted more.
The upper limit of the above amount is not particularly limited, but from the viewpoint of reducing the cost of the material and reducing the labor required to accommodate (supply) the calcium silicate-containing material in water for aquaculture, It is preferably 30 g/liter, more preferably 20 g/liter, and particularly preferably 15 g/liter.

From the viewpoint of maintaining good quality of the water for cultivation, shellfish cultivation is preferably carried out while pouring the water for cultivation. Specifically, aquaculture water pumped from a water source such as a river or the sea is supplied to a container (shellfish culture tank) containing the aquaculture water, and the aquaculture water overflowing from the container is Cultivate shellfish while continuously discharging.
Also, the shellfish are preferably cultivated above the calcium silicate-containing material and not in contact with the calcium silicate-containing material. By cultivating the shellfish above the calcium silicate-containing material, the pseudo-dung excreted by the shellfish such as oysters is allowed to fall in the vicinity of the calcium-silicate-containing material, thereby facilitating the decomposition of the pseudo-dung. can. In addition, by preventing contact between the shellfish and the calcium silicate material, it is possible to prevent shell discoloration (blackening of the shell due to exposure to hydrogen sulfide) due to the shellfish being buried in pseudo-feces and accumulated sludge. .

An example of the shellfish aquaculture system of the present invention will be described below with reference to FIG.
A shellfish culture system 1 includes an algae culture tank (not shown) for culturing algae, algae cultured in the algae culture tank, shellfishes 4, a calcium silicate-containing material 3, and water for culture. 9 and includes a shellfish culture tank 2 for cultivating shellfish 4 and a pipeline 5 for supplying algae from the algae culture tank to the shellfish culture tank 2 .
The shellfish culture tank 2 may have a pipeline 6 for supplying water 9 for culture. Aquaculture water 9 is supplied to the shellfish culture tank 2 from a water source such as a river or the sea through a pipeline 6 .
Further, the shellfish culture tank 2 may have a drain port 10 for discharging the culture water 9 overflowing from the shellfish culture tank 2 when supplying the culture water 9 from the pipe line 6. good. Aquaculture water 9 is discharged to a river, the sea, or the like through a drain port 10 .

The algae fermentor contains water for cultivation (usually the same as for aquaculture), algae, and other ingredients supplied as needed. A calcium silicate-containing material may be added to the culture water from the viewpoint of promoting the growth of algae.
An example of an algae culture tank includes a synthetic resin water tank with an open top, water for culture contained in the water tank, an air supply pipe attached to the water tank and inserted into the water for culture, and , a pipe line 5 for supplying diatoms to the shellfish culture tank 2.
The algae cultured in the algae culture tank are supplied to the shellfish culture tank 2 through the pipeline 5 together with water for culture. The pipeline 5 includes a pump for pumping up the cultured algae together with water for culture, and a valve for adjusting the amount of algae supplied to the shellfish culture tank 2 (amount of water for culture containing algae). and a mechanism such as a culture water supply pump for dilution.
Alternatively, a plurality of shellfish culture tanks may be provided for one algae culture tank, and algae may be supplied from the one algae culture tank to each of the plurality of shellfish culture tanks.

The shellfish culture tank 2 may have an air supply pipe 7 for supplying air into the water and stirring the water.
In order to prevent the calcium silicate-containing material 3 and the shellfish 4 from coming into contact with each other, a shelf 8 for placing the shellfish 4 (for example, a box-like box made of wire mesh and opened only at the top) is provided. ) may be provided above the calcium silicate-containing material 3 supplied to the shellfish culture tank 2. The shelf 8 for placing shellfish has, at least in part, a portion having water permeability (for example, a mesh-like portion with openings through which the water 9 for aquaculture passes but the shellfish 4 do not pass). are doing. Further, the shelf 8 for placing shellfish may have a plurality of steps. Further, instead of the shelf 8 for placing shellfishes, aquaculture of shellfishes may be carried out using a hanging chain that is used in general hanging type aquaculture of bivalves and the like.
The shelf 8 for placing shellfish and the hanging chain may be directly fixed to the shellfish culture tank, and fixed by a raft, a longline, a buoy, etc. for fixing the shelf 8 for placing shellfish and the hanging chain in the water. may have been

EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited to these examples.
[Materials used]
(1) Calcium silicate-containing material; Granular material containing 90% by mass or more of material having a particle size of 1 to 4 mm The content of soluble silicic acid in the calcium silicate-containing material is It was 21.1% by mass when measured according to "Fertilizer Test Method (2018)" supervised by the Safety Technology Center (FAMIC).
In addition, when the content of soluble lime in the calcium silicate-containing material was measured in accordance with "Fertilizer Test Method (2018)" supervised by the Independent Administrative Institution Agriculture, Forestry and Fisheries Food Safety Technology Center (FAMIC), 18. It was 7% by mass.

[Example 1]
25 liters of seawater pumped up from the sea was supplied as water 9 for culturing into a 30-liter shellfish culture tank 2 made of polycarbonate shown in FIG. Seawater is constantly supplied from the pipeline 6, and overflowing seawater is discharged from the drain port 10, so that the amount of seawater stored in the shellfish culture tank is always 25 liters. Also, the amount of seawater supplied per day was 50 liters, and the temperature of the seawater was 18±3°C.
Next, 125 g of the calcium silicate-containing material 3 is put into the shellfish culture tank 2, and 30 juvenile oysters (shellfish 4) are placed on the shelf 8 for placing shellfishes provided above the calcium silicate-containing material. placed.
In addition, after putting 10 liters of seawater and 50 g of calcium silicate-containing material into a 10-liter polycarbonate algae culture tank, diatoms (Chaetoceros gracilis) are cultured in the algae culture tank, and the cultured diatoms are cultured. The whole liquid (seawater) was supplied from the pipeline 5 to the shellfish culture tank.
Diatoms are supplied by aeration and agitation (air is supplied from the air supply pipe 7) by dividing about 1.25 billion diatoms per day into three times in consideration of the degree (size) of growth of the shellfish 4. Stirring by occasion) was performed.
At the start and after 1, 2, and 3 weeks, the oysters were collected, and the total mass of the oysters was measured after thoroughly wiping the surface of the oysters with a towel.
In addition, the rate of increase in the total mass of oysters ((total mass of oysters−total mass of oysters at the start)/total mass of oysters at the start×100 (%)) was calculated.
After 3 weeks, all the oyster shells were collected and calcined at 500° C. for 10 hours to be carbonized, and then the obtained carbonized substance was dissolved in 20% by mass hydrochloric acid while heating. Thereafter, solid-liquid separation was performed, and the amount of calcium contained in the oyster shell was measured from the resulting filtrate using an ICP emission spectrometer.

[Example 2]
Crested oysters were cultured in the same manner as in Example 1, except that the amount of calcium silicate-containing material put into the shellfish culture tank was 250 g, and the amount of calcium silicate-containing material supplied to the algae culture tank was 10 g. .
In the same manner as in Example 1, the total mass of oysters was measured.

[Comparative Example 1]
Except that materials containing calcium silicate are not used in shellfish culture tanks and algae culture tanks, and the amount of diatoms supplied is about 730 million pieces per day, taking into consideration the degree (size) of growth of shellfish 4. was cultivated in the same manner as in Example 1.
In the same manner as in Example 1, the total mass of oysters was measured.
In Examples 1 and 2 and Comparative Example 1, no individuals died during the cultivation.
Each result is shown in Table 1.

From Table 1, the mass of oysters cultured in Examples 1 and 2 (after 1 week: 6.94 to 7.08 g, after 2 weeks: 8.71 to 10.72 g, after 3 weeks: 9. 50 to 12.03 g) is the mass of oysters cultured in Comparative Example 1 (when no calcium silicate-containing material is supplied) (after 1 week: 5.17 g, after 2 weeks: 5.21 g, 3 weeks After passage: 5.26 g). In addition, the rate of increase in the total mass of oysters cultured in Examples 1 and 2 (after 1 week: 42.5 to 46.4%, after 2 weeks: 75.3 to 126.2%, after 3 weeks After: 91.1 to 153.8%) is the rate of increase in the total mass of oysters cultured in Comparative Example 1 (when no calcium silicate-containing material is supplied) (after 1 week: 9.8%, 2 After a week: 10.6%, After 3 weeks: 11.7%).
From these facts, it can be seen that the growth of shellfish is promoted in Examples 1 and 2.
In addition, the amount of calcium contained in the shell of the oyster cultured in Examples 1 and 2 (2,298 to 2,840 mg) was the same as the amount of calcium contained in the shell of the oyster cultured in Comparative Example 1 (1, 522 mg). In addition, when the size of the oysters cultured in Examples 1 and 2 and the size of the oysters cultured in Comparative Example 1 were visually compared, the oysters cultured in Examples 1 and 2 were larger.
From these results, it can be seen that in Examples 1 and 2, the formation of shells of shellfish is promoted.

1 Shellfish farming system 2 Shellfish farming tank 3 Calcium silicate-containing material 4 Shellfish 5 Conduit (conduit for supplying algae)
6 Pipeline (pipeline for supplying water for aquaculture)
7 air supply pipe 8 rack for placing shellfish 9 water for aquaculture 10 drain port

Claims (3)

an algae culturing step of accommodating the algae in culture water for culturing the algae and culturing the algae;
an algae supply step of supplying the algae cultured in the algae culture step into aquaculture water containing shellfish to be cultured and a calcium silicate-containing material;
In the aquaculture water to which the algae have been supplied in the algae supply step, the shellfish are placed above the calcium silicate-containing material without contact with the calcium silicate-containing material, and a shellfish culturing step of culturing while pouring the water for culturing at a position where the pseudo feces discharged by the shellfish can fall in the vicinity of the calcium silicate-containing material;
The calcium silicate-containing material contains a material having a particle size of 6 mm or less at a rate of 70% by mass or more, and the content of soluble silicic acid in the calcium silicate-containing material is 10 to 50% by mass. The lime content is 10 to 39% by mass,
A method for cultivating shellfish , wherein the amount of the calcium silicate-containing material contained in the water for culturing is 10 to 15 g/liter. 2. The method for cultivating shellfish according to claim 1 , wherein in the algae culturing step, the algae are cultured after supplying the calcium silicate-containing material into the culture water. The method for cultivating shellfish according to claim 2 , wherein the amount of said calcium silicate-containing material supplied in said culture water is 1 to 20 g/liter.

Images