JP2011147353A - Method for culturing shellfish - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for culturing shellfish by a suspending method, which can increase a number of cultures of shellfish per unit area of a raft or per unit length of a long line and efficiently performs a sorting operation. <P>SOLUTION: The method for culturing shellfish by a suspending method includes bonding shellfish to a net-like base material with a hydraulic composition comprising cement as a main component and suspending the base material. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for culturing shellfish in a hanging manner.

  As a method of culturing shellfish, a hanging type is generally used in which shellfish are attached to a base material such as a wire or a rope and cultured in the sea. Shells can be attached by attaching a basket to a wire or rope and placing an appropriate amount of juvenile shellfish in it (cargo culture), or by making a hole directly in the shell and fixing it with a vinyl string or a binding band. There are known methods (hanging ears), cultivating juveniles collected using scallops as a seedling device, etc. (hanging naked).

  However, when a cage is used, it is necessary to secure the distance between the ropes depending on the size of the cage, and the amount of culture is sometimes limited. The method of fixing with a vinyl string, a hook, or the like may not be usable depending on the type of shellfish, and requires a great deal of labor for the shell removal process after cultivation. Moreover, when it cultures using a seedling device as it is, when the shellfish are densely adhered, growth is suppressed, and the size may not be sufficient as a product, or the shape may be distorted.

For this reason, an aquaculture method has been developed in which a juvenile shellfish is fixed and suspended by an adhesive mainly composed of cement (Patent Documents 1 and 2).
In this aquaculture method, the number of shells that hang down per droop is less than in other drooping methods. Therefore, when cultivating a large amount of shellfish, the droop can be connected in the vertical direction, The number of aquaculture is increased by narrowing the interval when hanging on a longline. However, depending on the aquaculture area, there are cases where the drooping series cannot be connected due to the shallow water depth, or the interval cannot be narrowed to prevent the drooping series from coming into contact with the waves.

  On the other hand, in the conventional cage farming, the number is adjusted according to the target size, the shellfish is put in the cage and cultured, and it is shipped as a product after growing to an appropriate size . In this case, it is necessary to take out all the shellfish from the cage once, sort them, and return them to the cage again after completion. When a relatively small shellfish is cultivated, there may be about 70 shellfish per cage, and there is a problem that a large amount of labor is required when performing a large amount of sorting work.

JP 2008-206496 A JP 2008-237036 A

  Accordingly, an object of the present invention is to increase the number of shellfish cultivated per unit area of a cocoon or unit length of a longline in a method for culturing shellfish in a hanging manner, and to perform sorting work efficiently It is to provide a method for culturing shellfish.

  As a result of various studies in view of such circumstances, the present inventors have found that when a shellfish is attached to a net-like substrate and suspended by a hydraulic composition mainly composed of cement, or It has been found that the number of shellfish cultured per unit length of longline can be increased, and that the sorting operation can be performed efficiently, and the present invention has been completed.

  That is, the present invention relates to a method for culturing shellfish, characterized in that, in the method of culturing shellfish in a hanging manner, the shellfish is attached to a net-like substrate and suspended by a hydraulic composition mainly composed of cement. It is to provide.

  According to the present invention, it is possible to increase the number of shellfish cultivated per unit area of the cocoon or unit length of the longline in the hanging culture of shellfish, and to efficiently perform the sorting operation after the culture. Can do. In particular, it is suitable for aquaculture when the water depth is shallow.

It is a figure which shows the example of the shape of a net-like base material. It is a figure which shows the example at the time of bonding shellfish to a net-like base material. It is a figure which shows the example at the time of adhere | attaching shellfish to a net-like base material using a corrugated work table. It is a figure which shows the example at the time of adhere | attaching shellfish to a net-like base material using a corrugated work table. It is a figure which shows the cross section at the time of bonding shellfish to a net-like base material using a corrugated work table. It is a figure which shows the example at the time of adhere | attaching shellfish on the net-like base material with an opening part. It is a figure which shows the example of the shape of an opening part. It is a figure which shows the example of the drooping method. It is a figure which shows the example of the drooping method. It is a figure which shows the example of the drooping method. It is a figure which shows the example of the drooping method.

The hydraulic composition used in the present invention is mainly composed of cement.
As the cement used here, in addition to Portland cements, blast furnace cement, fly ash cement, slag cement, eco-cement, alumina cement, etc., mixed in an appropriate ratio of one or more can be used. It is. From the viewpoint of workability and strength development, it is particularly preferable to use early-strength Portland cement and ordinary Portland cement. These cements can be used alone, but if necessary, admixture of fine aggregates, gypsum, limestone powder, dolomite, slag, silica fume, calcium aluminate, etc. that are generally used in cement and concrete. A mixture of materials can also be used.
The cement is preferably contained in the hydraulic composition in an amount of 20 to 90% by mass, particularly 35 to 80% by mass.

In addition, the hydraulic composition can contain alkali metal and alkaline earth metal carbonates, sulfates, nitrites, nitrates, chlorides, hydroxides, and the like in order to adjust the curability.
These materials can be used alone or in combination of two or more, and are preferably contained in the hydraulic composition in an amount of 0.1 to 10% by mass, particularly 1 to 7% by mass.

  Further, in the hydraulic composition, as a material for adjusting the fluidity and curability of the adhesive slurry, a curing accelerator, a setting retarder, a shrinkage reducing agent, and an AE agent that are generally used for cement and concrete. Additives such as water-reducing agent, high-performance water-reducing agent, high-performance AE water-reducing agent, fluidizing agent, thickener, defoaming agent, etc., will affect the properties of the adhesive slurry, adhesion and the state of the shellfish One or two or more may be added in combination as long as they are not present. These materials may be mixed in advance with the powder of the hydraulic composition depending on the form, or may be dissolved in water at the time of kneading. Further, after confirming the state of the kneaded slurry, a necessary amount can be added to the slurry later and kneaded again.

  The hydraulic composition is mixed with water and kneaded to form a slurry, which is used as an adhesive. These mixing ratios are preferably 25 to 50 parts by mass, particularly 30 to 40 parts by mass with respect to 100 parts by mass of the hydraulic composition.

  The slump value of the slurry is 30 mm or less, in particular 10 to 25 mm; and the flow value of the slurry is 80 mm or less, particularly 60 to 70 mm, because the workability is good, and after applying the adhesive, It is preferable because it can stay without flowing down.

Examples of shellfish cultivated by the method of the present invention include oysters and scallops, and are particularly suitable for oyster culture.
As the shellfish, shellfish collected by a seedling device can be used by a usual method. The size of the juvenile shellfish is preferably 1.5 to 10 cm, particularly 3 to 8 cm.

As the net-like base material used in the present invention, a net used for fishery can be used.
The material is preferably made of synthetic fibers such as polyvinyl alcohol, polyvinylidene chloride, polyamide, polypropylene, and polyethylene. As a netting method, a knot net, a knotless net, a cocoon net, a woven net, or the like can be used.
The thickness of the mesh thread is appropriately adjusted depending on the shape and mesh of the mesh, but it is usually preferable that the thickness of the stranded wire used for the substrate is 0.5 to 3 mm.
The mesh is preferably 1 to 50 mm, particularly preferably 3 to 35 mm, and the shape may be any of rhombus, square, hexagon and the like.
The shape of the reticulated base material is not particularly limited, and may be any of a sheet type, a strip type, a ribbon type, etc., as shown in FIG. In addition, the size of the net-like base material is preferably 1.5 m in length and 2 m in width or less as the size in the case where the drooping series is formed with one base material.

In the present invention, shellfish are fixed to such a net-like base material using an adhesive made of the slurry as described above.
Specifically, for example, as shown in FIG. 2, the shells are arranged in the same direction so that the area of each shell is about 15 cm long × 10 cm wide, and 5 mm between the shells from above. Install a net-like substrate and fix both ends so that a gap of a certain degree is formed. Apply adhesive slurry from the top of the base material, and then put another shellfish on top of it, set the number of bonds per place to two, and press lightly so that the shellfish and the adhesive are in close contact, then let stand Then, the adhesive is cured to obtain a drooping series.
In addition, when using a corrugated work table, install a net-like base material from the top of two shells arranged in the valley of the work table, apply adhesive slurry from above, and further from above By bonding shellfish, the number of bonds per location can be increased to 3 or more (FIGS. 3 to 5).

  The amount of the adhesive applied per point of adhesion is preferably 10 to 100 g in accordance with the size and shape of the shellfish, and 30 to 70 g is a general purpose application rate.

In addition, when using the net-like base material of 10 mm or less of meshes, you may have the opening part for adhere | attaching shellfish (FIG. 6). By having an opening part, it becomes easy to adhere shellfish.
The shape of the opening is preferably uniformly spread on the surface of the shellfish, and is preferably a circle or a square. In addition, in a vertically long shell such as an oyster, an elliptical shape, a rectangular shape, or a rhombus shape corresponding to the length direction is preferable (FIG. 7).
The size of the opening varies depending on the shape rather than the size of the shellfish to be bonded, but in the case of a circle or square, the diameter or length of one side is preferably 30 mm or less, and in the case of an ellipse, rectangle or rhombus, the length Is preferably 50 mm or less and the width is 30 mm or less.

What is necessary is just to cultivate shellfish by the usual method by dripping the obtained drooping series in the sea.
As a drooping method of the drooping series, for example, as shown in FIG. 8, the upper part is directly hung on a ridge or a long line using a wire, a rope, or the like in a state where the net-like base material is spread. Moreover, as shown in FIG. 9, after fixing the upper part of a net-like base material to a fixing tool previously, you may hang | hang a plurality of drooping stations collectively on a hook or a long line. As the fixture, rods made of wood, plastic, synthetic resin, metal, ropes bundled with steel fibers, synthetic resin fibers, carbon fibers, etc. can be used, and these can be used with Teflon (registered trademark), rubber, What was covered with plastic, vinyl, etc. can also be used.
Furthermore, 1 or 2 or more of the net-like base material which adhere | attached shellfish can be fixed to a frame, and it can also hang | suspend as a shape of a cylinder or a prism (FIG. 10).
In addition, an outer frame for capturing the shells that have fallen can be installed outside the drooping run (FIG. 11).

  The method of the present invention can be applied to any aquaculture area, but the water depth is relatively shallow, especially when the drooping series contacts the seabed due to the influence of waves, or when the drooping series cannot be drooped. More effective when used in sea areas. In particular, it is suitable for use at a water depth of approximately 5 m or less.

  In the examples, those shown in Table 1 were used as the base material of the drooping series.

Example 1
Hayashi Portland Cement (manufactured by Taiheiyo Cement Co., Ltd.), limestone powder (manufactured by Yusheng Mining Co., Ltd., 200 mesh product), blast furnace slag fine powder (manufactured by Dai Shi Co., Ltd., brain value 4000 products), calcium chloride (manufactured by Central Glass Co., Ltd., flakes) The product was weighed according to the formulation shown in Table 2, and mixed for 2 minutes with a Redige mixer to obtain a hydraulic composition. 10,000 g of this was weighed into a Toslon can, tap water was added to a water powder ratio of 35%, and kneaded for 3 minutes with a hand mixer to obtain an adhesive slurry.

  Arrange oyster shells of about 5-10cm in length on a flat work table so that the area of each oyster shell is 12cm in length x 10cm in width, with the right shell facing down, and in the same direction. A base A net cut to a size of 1 m in length and 1.6 m in width was installed so that a gap of about 5 mm was formed between the oyster and the oyster, and both ends were fixed. Apply about 60 g of adhesive slurry from above the base material with a metal spoon, and then place another oyster shell on top of it so that the right shell is on top, and the number of bonds per place is two, After pressing lightly so that the oyster juvenile and the adhesive were in close contact with each other, the oyster shell was allowed to stand for 1 day to cure the adhesive, and a drooping series A was produced.

On the other hand, on the corrugated work table, oyster shells with a length of about 7 cm are spaced 5 cm apart (12 cm in total with the oyster shells), and the right shell is placed so that two oyster shells are V-shaped. The base material B rope having a length of 2 m was placed from above and arranged so that the base material was centered, and then both ends were fixed with hooks. From there, apply about 60 g of adhesive slurry, and then place another oyster shell on top of it so that the right shell is on top, and the number of bonds per place is three, After pressing lightly so as to be in close contact with the oyster shellfish with the base material as the center, the adhesive was cured by allowing to stand for 1 day to produce a drooping series C.
Further, an age pin was installed on the rope of the base material B at intervals of 12 cm, and a drooping series D for ear hanging culture was prepared by attaching eight oysters through which holes were drilled in shells per one place and passed through a teg.

The produced droops A, C and D were drooped on a long line, and the number of oyster droops when various droops were used was measured with the horizontal length (1.6 m) of the droop run A as a unit length. In the drooping series C and D, the number of droops per unit length was set to 5 assuming that the distance between the drooping series when cultivating by the conventional method was 30 cm.
The results are shown in Table 3.

Example 2
(1) Production of drooping series:
A drooping series A produced in Example 1 was formed into a cylindrical shape by attaching a circular frame having a diameter of 50 cm to the upper end and the lower end. Further, the base material C was connected in five stages in the vertical direction so that the total length was about 1 m, and a drooping series E containing 50 oyster shells per stage was produced.

(2) Drooping drooping:
The drooping series B and E were hung on the longline in the same manner as in Example 1, and the number of oyster droops per unit length was measured based on the width of the drooping series A. The drooping series B and E have the same drooping area, and the diameter of the base material C and the frame is 50 cm. Therefore, the number of drooping per unit length was three.
The results are shown in Table 4.

  From the results of Tables 3 and 4, according to the present invention, it is possible to increase the amount of shellfish cultured per unit length to the same extent as that of cage culture or ear suspension culture, and an increase in yield is expected. The Moreover, the sorting operation can be performed without removing the shellfish from and out of the cage as in the case of cage cultivation, and the sorting operation becomes efficient.

Claims (6)

  A method for cultivating shellfish, characterized in that the shellfish is suspended by adhering to a net-like base material with a hydraulic composition mainly composed of cement in a method for culturing shellfish in a hanging manner.   The method for culturing shellfish according to claim 1, wherein the water depth of the cultured sea area is 5 m or less.   The method for cultivating shellfish according to claim 1 or 2, wherein the mesh of the reticulated base material is a lattice having a mesh of 1 to 50 mm.   The method for culturing shellfish according to any one of claims 1 to 3, wherein the net-like base material has an opening for bonding shellfish.   The method for cultivating shellfish according to any one of claims 1 to 4, wherein one or more of the net-like base materials to which shellfish are bonded are fixed to a frame and suspended as a columnar or prismatic shape.   The shellfish cultivation method according to any one of claims 1 to 5, wherein an outer frame for capturing the shellfish that has fallen is installed outside the drooping chain.

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