JP2017055719A - Seedling stocking method of sea cucumber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seedling stocking method of sea cucumber in which the sea cucumber can stably be mass-produced without taking labor and cost in comparison with a former method.SOLUTION: A seedling stocking method of sea cucumber concerning the present invention includes: a step of alternately laminating a shell layer 12 with shell 11 spread all over and a second net 10 with sea cucumber seedling adhering thereto in a bag-shaped first net 13, and interposing the second net 10 between the shell layers 12; a step of setting up a cylindrical body 15 with multiple through-holes 15a formed in an outer circumferential part in the seabed; and a step of inserting the first net 13 with the shell 11 and the second net 10 stored therein to the cylindrical body 15 set up in the seabed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sea cucumber seedling release method.

  In recent years, in China, the wealthy class has increased due to rapid economic development, and the demand for sea cucumbers, which are high-quality foods, has expanded. Along with this, sea cucumber products exported from Japan to China are rapidly increasing. However, if sea cucumbers are overfished, sea cucumber resources will be depleted and stable supply of sea cucumbers will not be possible. Therefore, sea cucumbers are cultivated or proliferated as a measure to recover sea cucumber resources.

  Aquaculture occupies a certain area, manages the life and environment of self-owned seafood, algae, etc. in that area, breeds and grows these organisms, and grows to the target size (product size) It is a method to do. For example, in patent document 1, a baffle is arrange | positioned above the lattice frame for the sea cucumber storage arrange | positioned at the bottom part of a culture tank main body, and a side net | network is stretched by the water flow window provided in the side wall of the culture tank main body. In addition, a sea cucumber aquaculture facility is disclosed in which a top net is stretched at the top opening of the main body of the aquaculture tank.

  Proliferation refers to means and techniques for recovering fishery resources in natural waters, or for more actively increasing and maintaining natural resources. In the case of sea cucumbers, artificial seedlings and natural harvesting There are seedlings.

In sea cucumber artificial seedlings, eggs and sperm collected from a parent sea cucumber are mixed and fertilized, and hatched larvae are collected and larva reared. The juvenile sea cucumber that has grown to a length of about 15 mm to 20 mm is discharged into a reef zone and a boulder zone with a depth of 10 m or less, and is released from a ship by direct diving.
Natural seedlings, on the other hand, are less costly and less labor-intensive than artificial seedlings, but depend on natural reproductive power and are greatly affected by environmental conditions.

Japanese Utility Model Publication No. 64-43666

(Germany) Aomori Prefectural Industrial Technology Center Fisheries Research Institute, “Sea cucumber seedling release manual”, March 2012

The released juvenile sea cucumber is depleted under the influence of food damage and tidal currents caused by the enemy. In Non-Patent Document 1, a survey is conducted on the residual rate of released sea cucumbers in sea areas with different bottom sediments. In this survey, a 10m square test zone was set for each sea area with different bottom sediments, and 1000 or 2000 juvenile sea cucumbers with a body length of about 20 mm were released into the center 1 m ² of each test zone. We are regularly investigating the remaining movements. As a result, it was reported that the number of juvenile sea cucumbers decreased immediately after the release in all the test areas, and almost no habitat of juvenile sea cucumbers could be confirmed in the center 1 m ² of the test area 20 weeks after the release. .

Thus, although it is unavoidable that the released juvenile sea cucumber is depleted, it is generally said that the larger the size of the juvenile sea cucumber to be released, the higher the release effect. However, the production of large seedlings is not only labor and cost intensive, but also has a problem of limited production.
The “seed and seedling” refers to eggs and larvae of aquatic animals used for aquaculture and release. In this specification, sea cucumber larvae and juvenile sea cucumbers are collectively referred to as “seed and seedlings”.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a sea cucumber seedling discharge method that can stably mass-produce sea cucumbers without requiring labor and cost as compared with the prior art.

To achieve the above object, the sea cucumber seedling release method according to the present invention is characterized by comprising the following steps.
(1) A shell layer in which shells are spread and a second mesh with sea cucumber seedlings are alternately stacked in a bag-shaped first net, and the second net is interposed between the shell layers. (2) A step of standing a cylindrical body having a plurality of through-holes formed on the outer periphery thereof on the sea floor (3) A first net containing the shell and the second net standing on the sea floor Inserting into the provided cylinder

  In the present invention, sea cucumber seedlings move their habitat from the second net into the shell adjacent to the second net as the seedlings grow. Meanwhile, sea cucumber seedlings are protected from harmful enemies and tidal currents by cylinders and shells inside the cylinders. In the shell, juvenile sea cucumber (seed seedling) that has grown to a certain size moves out of the cylinder from the through-hole formed in the cylinder and inhabits around the cylinder.

  In the sea cucumber seedling discharge method according to the present invention, it is preferable that stones are stacked around the cylindrical body standing on the seabed.

  In this configuration, the cylinder is fixed to the sea floor with stones so that the cylinders are not washed away by tidal currents, and the gaps between the stones become new habitats for juvenile sea cucumbers that have moved out of the cylinders. Protect the juvenile sea cucumber.

  In the sea cucumber seedling release method according to the present invention, it is possible to provide a habitat according to the growth process of sea cucumber seedlings while eliminating the effects of harmful enemies and tidal currents, so the residual rate of sea cucumber seedlings after release is high, The sea cucumber can be mass-produced stably without taking such labor and cost.

It is a disassembled perspective view for demonstrating the procedure of the sea cucumber seedling discharge method which concerns on one embodiment of this invention. It is an elevation sectional view of the cylinder installed in the seabed.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.

The procedure of the sea cucumber seedling release method according to an embodiment of the present invention will be described with reference to FIGS.
(1) A bag-shaped first net 13 having an upper end as an opening is set in a bottomed cylindrical or inverted frustoconical cage 14 formed of a wire rod. In that case, if the opening part of the 1st net | network 13 is folded back outside, it will become easy to do the subsequent operation | work.

(2) A shell layer 12 is formed by spreading the shells 11 in the first net 13 so that the bottom is not visible. At that time, the shells 11 are spread as if a wall is formed in the periphery, and sea cucumber seedlings attached to the second net 10 described later are prevented from deviating sideways.
(3) On the spread shells 11, that is, the shell layers 12, the second net 10 with sea cucumber seedlings attached is laid. In order to prevent the second net 10 from being seen from the outside, the second net 10 is accommodated in the shell 11 as much as possible. However, when the second net 10 is placed in the shell 11, it is handled carefully so that the sea cucumber seedlings do not deviate.

(4) A shell layer 12 is formed on the second net 10 by spreading the shell 11 so that the second net 10 is not visible. At that time, as before, the shells 11 are spread like a wall around. In addition, when the shell 11 is pushed in, there is a possibility that the sea cucumber seedlings attached to the second net 10 may be crushed.
(5) The above operations (3) and (4) are repeated about 4 to 5 times to form a laminated body in which the second net 10 is interposed between the shell layers 12 in the first net 13. . Thereafter, the upper end of the first net 13 is closed to close the opening.

(6) The cylinder 15 having a plurality of through holes 15a formed on the outer peripheral portion is erected on the seabed 17 having a depth of 10 m or less (preferably about 5 m), and a stone 16 is stacked around the cylinder 15.
(7) The first net 13 in which the shell 11 and the second net 10 are stored is inserted into the cylinder 15 erected on the seabed 17 in a state where the first net 13 is placed in the cage 14. When there is a gap between the cage 14 and the cylinder 15, the shell 11 is sandwiched in the gap so that the first net 13 does not move.

  The material of the cylinder 15 is a synthetic resin such as vinyl chloride. In the present embodiment, the outer diameter of the cylinder 15 is 30 cm, the height is 60 cm, the diameter of the through hole 15a is 5 cm, and the distance between the centers of the through holes 15a is 10 cm. The material of the wire constituting the cage 14 is a synthetic resin such as polypropylene, and the outer diameter of the cage 14 is approximately the same as the inner diameter of the cylinder 15.

As the shell 11, a shell having a rough surface such as an oyster shell or a scallop shell is preferable.
The seedlings that are attached to the second net 10 are those that are about 10 days to 2 weeks old.

  The first net 13 is made of a synthetic resin such as polyethylene and has a mesh (mesh size) of about 10 mm to 15 mm. The second net 10 is made of synthetic resin such as nylon and has a mesh size of about 0.2 mm to 0.3 mm.

  The stone material 16 is preferably about 15 to 30 cm in size.

  The sea cucumber seedlings attached to the second net 10 move from the second net 10 to the shells 11 adjacent to the second net 10 as they grow. A juvenile sea cucumber (seed seedling) that has grown to a certain size in the shell 11 moves from the through-hole 15a formed in the cylindrical body 15 to the outside of the cylindrical body 15, and is stacked around the cylindrical body 15 The gap between 16 is a new habitat. Sea cucumber seedlings are protected from harmful enemies and tidal currents by the cylinder 15, the shell 11 or the stone 16 in the cylinder 15.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the configuration described in the above-described embodiment, and is within the scope of matters described in the claims. Other possible embodiments and modifications are also included. For example, in the above-described embodiment, the cylindrical body has a cylindrical shape, but is not limited to this, and may have another shape such as a polygonal column. Moreover, in the said embodiment, although the cylinder is made from a synthetic resin, it is good also as a product made from FRP, concrete, etc.

10: second net, 11: shell, 12: shell layer, 13: first net, 14: basket, 15: cylinder, 15a: through hole, 16: stone, 17: seabed

Claims (2)

  A step of alternately stacking a shell layer in which shells are spread and a second mesh to which seedlings of sea cucumber are adhered in a bag-like first net, and interposing the second net between the shell layers; The cylinder in which a plurality of through holes are formed on the outer periphery of the cylinder, and the first net in which the shell and the second net are accommodated is provided on the sea floor. A seed insertion method for sea cucumber, characterized by comprising the step of inserting into the body.   The sea cucumber seedling discharge method according to claim 1, wherein stones are stacked around the cylindrical body standing on the seabed.

Images