JP2001211778A - Reef for growing shellfish and method for growing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reef for growing shellfishes capable of accelerating the growth of planted spats or young shellfishes, and a method for growing the same. SOLUTION: This reef for growing shellfishes 1 is equipped with a mounting base for fixing plates 6 attached with sea algae as freely attaching and detaching, and recessed parts 8 where the spats or young shellfishes take refuge from their natural enemies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reef for growing shellfish and a method for growing the same.

[0002]

2. Description of the Related Art In recent years, the shellfish fishery has changed from a fishery that simply captures naturally breeding abalone, for example, to a cultivation fishery that releases and releases young or young shellfish to fishing grounds such as abalone and turban shells. Has begun.

[0003] In order to support such a change in the shellfish fishing industry, concrete blocks for assisting the growth of shellfish have been installed in the sea area of the shellfish breeding ground, that is, in shellfish fishing grounds. Are, for example, "Convex Block" (trade name) manufactured and sold by Marine Civil Engineering Co., Ltd. and "GRA Block" (trade name) manufactured and sold by Tokuyama Corporation.

[0004] On the other hand, it has been reported that rocky shores have occurred due to changes in the natural environment such as deforestation or the inflow of domestic water. Under such circumstances, Sumitomo Osaka Cement Co., Ltd. has proposed a new concept called a removable seaweed bed reef from the viewpoint of seaweed bed creation. This proposal proposes that seaweeds are intermediately grown on a number of algae growing plates suspended from the raft in the sea, and the plate with the seaweeds attached to the seaweed bed pedestal. It is to make.

In other words, according to the idea of a detachable seaweed bed breeding reef proposed by Sumitomo Osaka Cement Co., Ltd., seaweed is intermediately grown using algae growing plates in another place, and on the other hand, for example, installed on the seabed When the seaweed on the seaweed bed pedestal has declined, the density of the newly created seaweed forest can be maintained by collecting the alga growing plate from the seaweed bed pedestal and replacing it with a new alga growing plate.

[0006]

[Problems to be Solved by the Invention] By the way, the environment of the coastal sea area is changing year by year, and what used to be a breeding ground for abalones and turban shells is now reduced to a seaweed bed. It has been reported that natural breeding has become difficult. In addition, even if young larvae or young oysters are released, there have been reports of cases in which the growth efficiency is reduced due to a shortage of seaweed as a bait and / or damage by natural enemies such as octopus during the growth process. .

Accordingly, an object of the present invention is to provide a breeding reef and a breeding method for shellfish which can promote the growth of released juvenile shellfish or juvenile shellfish. Another object of the present invention is to provide a breeding reef and a breeding method for shellfish that can revive a fishing ground in which the efficiency of breeding shellfish such as abalone has declined due to the decline of seaweed beds such as alame and scallop. is there. A further object of the present invention is to provide an environment in which shellfishes are difficult to grow due to a lack of seaweed as a feed, although they have basic conditions suitable for growing shellfish such as abalone in terms of water temperature and the like. It is an object of the present invention to provide a breeding reef and a breeding method for shellfish which can be converted into a shellfish breeding ground. Another object of the present invention is to provide a method for growing shellfish which can protect juveniles or young shellfish from natural enemies such as octopus.

[0008]

According to one aspect of the present invention, there is provided a mounting seat for removably fixing a plate to which seaweeds are attached, and a method in which a juvenile or young shellfish is removed from a natural enemy. This is achieved by providing a shellfish reef comprising a recess for evacuation.

Further, according to another aspect of the present invention, there is provided a mounting seat for detachably fixing a plate to which seaweed is attached, and a method for evacuating a juvenile or juvenile shellfish from a natural enemy. A step of preparing a shellfish reef with a recess of
Fixing the plate on which the seaweed is attached to the mounting seat of the shellfish reef, installing the shellfish reef on the sea floor, and throwing a juvenile or young shellfish in the sea area where the shellfish reef is installed This is achieved by providing a shellfish growing method including the following.

That is, according to the shellfish reef and the shellfish growing method according to the present invention, the shellfish rearing reef is provided, for example, at a shellfish fishing ground, thereby providing seaweed to be used as bait for the released juvenile shellfish or young shellfish, while providing seaweeds from the natural enemies. You can give yourself a safe haven. Thereby, the breeding of the released juvenile shellfish or juvenile shellfish can be promoted.

In addition, the shellfish reef and the shellfish growing method according to the present invention, which had been a breeding ground for abalones and turtles, have now lost their seaweed beds, making it difficult for natural breeding of abalones and the like. It is considered that the practice is most commonly carried out in sea areas, but separately from this, it is possible to conduct this study in a sea area that lacks only seaweed as a feeding environment for shellfish, so that this sea area can be used for shellfish such as abalone Can be changed to a fishing ground. In other words, although the natural propagation of shellfish has not been observed so far, by implementing the present invention in a sea area where conditions such as water temperature are suitable for growing shellfish, it is possible to change this sea area to a fishing ground for shellfish such as abalone. Become.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The shell breeding reef according to the present invention is preferably provided with a mounting seat for removably fixing a plate with seaweed attached to a lateral surface extending in a lateral direction. The lateral surface has a convex portion projecting vertically from the lateral surface, and an overhang portion is formed on the side surface of the convex portion, the upper portion of which protrudes more outward than the lower portion, and the overhang portion forms a shadow. It is preferable that a concave portion is formed in the portion where the young shellfish or the young shellfish escape from the natural enemy. According to this, the juvenile shellfish or the juvenile shellfish can spend a calm life in the shade formed by the overhang portion, and can escape into the recess when attacked by a natural enemy.

Further, it is preferable that the convex portion is formed of a concrete block to which a rough rock surface of natural rock is transferred. Such unevenness can enhance the viability of natural seaweed, unlike the conventional shellfish reef that is formed on a flat surface. Further, the shellfish reef according to the present invention,
It is preferably made from concrete containing calcined diatomaceous earth powder. By using such concrete, it is possible to reduce the influence on the ecosystem of the sea area into which the shellfish-growing reef is introduced, and to quickly create a favorable biological environment after installation.

In the method of growing shellfish according to the present invention, the seabed on which the shellfish growing reef is installed preferably has a depth of 1 to 3 m. "Ezo abalone" in such relatively shallow waters
It has been found by experiments of the inventors that an unprecedented good breeding effect can be obtained when larvae or larvae are grown. Further, when growing at such a relatively shallow water depth, it becomes easy to surround the shellfish growing reef with a natural enemy invasion fence having a height almost equal to the water depth. In other words, by surrounding the shellfish reef with a natural enemy intrusion prevention fence having substantially the same height as the water depth, the invasion of octopus and the like can be substantially prevented.

This natural enemy intrusion prevention fence may be constituted by a wall made of concrete, but is constituted by a net means such as a net made of metal or synthetic fiber or natural fiber having a mesh size which makes it difficult for an octopus or the like to enter. You may. In the case where the natural enemy intrusion prevention fence is made by such a net means, the cost required for this can be greatly reduced as compared with the case where it is made of concrete. Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the invention.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate preferred embodiments of the present invention. Among these drawings, FIGS. 1 to 5 are detailed views of the shell breeding reef of the first embodiment, and FIGS. 6 to 8 are detailed views of the shell breeding reef of the second embodiment.

Reference numeral 1 in the first embodiment (FIGS. 1 to 5) indicates the whole shellfish reef of the first embodiment. The shell breeding reef 1 is composed of a base 2 that is placed on the seabed to form a pedestal of the shell breeding reef 1 and an upper block 4 that protrudes upward from the base 2. After being made separately, they are integrated before being installed on the sea floor.

The base 2 and the upper block 4 each have a rectangular shape when viewed in plan, more specifically, a substantially square shape, and the side surfaces 2a, 4a gradually become inner as they go downward. It is set to the reverse slope located on the side. That is, each side surface 2a, 4a is formed by an overhanging wall surface. However, the side surface 2a of the base 2 does not necessarily have to be formed of an overhanging wall surface, and a portion of the side surface 2a may be overhanging. Further, the upper block 4 does not need to have all of its side surfaces 4a overhanging, and may have a part of which has an overhanging surface.

The upper block 4 is formed of a substantially horizontal surface whose upper surface 4b is relatively flat and spreads in the horizontal direction. The upper surface 4b is typically provided with the above-described algae proposed by Sumitomo Osaka Cement Co., Ltd. A growth plate 6 (originally, seaweeds grown on this plate 6 should be drawn, but the presence of seaweed is omitted in the drawing to avoid complication of the diagram). For receiving, a recess having a contour shape complementary to the plate 6 or a mounting seat (this recess is not shown in the drawing because the plate 6 is schematically shown in the drawing) is formed. The plate 6 to be installed and fixed in the depression is not a plate in which seaweed grown in the middle by the method proposed by Sumitomo Osaka Cement Co., Ltd. is propagated, but a natural seaweed is harvested and the root of this natural seaweed is collected. For example, a plate bonded with a submersible pound may be used.

The number of depressions formed in the upper block 4 for receiving the plate 6 is determined by the relationship between the size of the upper block 4 (the area of the upper surface 4b) and the size (area) of the plate 6. In this embodiment, four depressions are arranged so that the four plates 6 can be installed at an appropriate distance from each other. Although the bottom surface of the upper block 4 is not shown in the drawing, it is formed of a horizontal plane. A shell breeding reef 1 comprising a base 2 and an upper block 4 forming a projection projecting upward from the base 2.
Before being installed on the seabed, the base 2 and the upper block 4 are bonded together using concrete to be integrated on land.

A means (not shown) for firmly fixing the plate 6 around the depression of the upper block 4
By operating the fixing means, the plate 6 can be fixed and the fixing of the plate 6 can be released. As such a fixing unit, a conventionally known appropriate unit may be adopted.

The base 2 has a shape considerably larger than that of the upper block 4, and a seating surface 2c formed of a horizontal surface on which the upper block 4 is placed is formed at the center of the upper surface 2b of the base 2. Around this seat surface 2c, a shelf for mounting the plate 6 is formed.

That is, an outer peripheral region 2d surrounding the central seating surface 2c on the upper surface 2b of the base 2 is formed of a surface extending in the lateral direction, and a plurality of depressions for receiving the algae growing plate 6 are provided in the outer peripheral region 2d (see FIG. Since the plate 6 is schematically illustrated in FIG. 2, this depression does not appear in the drawing.)
Are formed at a distance from each other, and around this depression, similarly to the depression of the upper block 4, means (not shown) for firmly fixing the plate 6 are provided. By operating, the plate 6 can be fixed, and the fixing of the plate 6 can be released.

In the outer peripheral region 2d of the base 2, a pair of corners located on a diagonal line is formed with a ridge 2e which is raised in a mountain shape. Corresponding to the pair of ridges 2e, the lower portions of the pair of opposing corners of the upper block 4, as can be best understood from FIGS.
The notch 4f which can receive e is formed.

A surface exposed to the outside of the base 2 and the upper block 4, that is, an outer peripheral region 2d of the upper surface 2b of the base 2
And the side surface 2a and the upper surface 4b and the side surface 4a of the upper block 4 are formed with irregular irregularities similar to the rock surface of natural rock. The method for producing such a pseudo-rock block can be relatively easily produced, for example, by using a mold material made of a known thermoplastic elastomer (rubber elastic body) proposed by Sumitomo Osaka Cement Co., Ltd. The irregular asperities resembling the rock surface of the natural rock include at least the side surface 2a of the base 2 and the upper block 4,
4a, and the upper surfaces 2b, 4b may be formed as flat surfaces.

The overhanging side surface 4 of the upper block 4
In this embodiment, as a shaded portion of a, a recess 8 is formed in the darkest portion so that the juvenile shellfish or the juvenile shellfish can escape from the natural enemy. The recess 8 may be formed at an appropriate place such as a portion. This recess 8 is preferably a groove having an appropriate depth in order to prevent the larvae or the larvae from escaping, and is preferably not continuous around the upper block 4. . From this viewpoint, in the embodiment, the upper block 4
At each of the four corners, a groove 8 is formed in cooperation with the base 2. The four grooves 8 are independent of each other without being continuous, so that it is possible to suppress the generation of a dead water region where the flow of seawater is stagnant, as compared with the case where the grooves 8 are continuous along the entire circumference of the upper block 4. There is an advantage. Of the grooves 8 formed at the four corners, the groove formed by the notch 4f of the upper block 4 and the raised portion 2e of the base 2 is an inclined groove.
The water flow flowing along this groove can be directed from top to bottom or from bottom to top.

The opening of the groove 8 is set to a height of about 50 mm, and its depth is about 80 when measured at the deepest point, that is, at the four corners of the upper block 4.
It has dimensions of mm. The opening and the depth, in particular, the height dimension of the opening may be determined based on the viewpoint that it is effective to prevent the invasion of the octopus which is the natural enemy of the abalone.

Second Embodiment (FIGS. 6 to 8) A shell reef 20 of the second embodiment has a flat plate plate 21 having a square thickness when viewed in plan. More specifically, if the flat plate 21 is a concrete product and has a height of about 1 to 3 meters and a size of about 2 meters on one side, it is not affected by wave force due to its own weight, and the sea floor is not affected. The state fixed in can be maintained. In addition,
One or more drain holes (not shown) penetrating vertically are formed in the flat plate 21 to prevent the flat plate 21 from being lifted up by the influence of the water flow entering the lower side of the flat plate 21. You may do so.

On the upper surface of the flat plate 21, the above-mentioned algae growing plate 6 proposed by Sumitomo Osaka Cement Co., Ltd.
(Originally, seaweed grown on this plate 6 should be drawn, but in order to avoid confusion of the drawing diagram,
A recess having a contour shape complementary to the plate 6 for receiving the seaweed is omitted in the drawing (this recess is not shown in the drawing because the plate 6 is schematically shown in the drawing). .) Are formed at intervals. The plate 6 to be installed and fixed in the depression is not a plate in which seaweed grown in the middle by the method proposed by Sumitomo Osaka Cement Co., Ltd. is propagated, but a natural seaweed is harvested and the root of this natural seaweed is collected. For example, a plate bonded with a submersible pound may be used.

Further, on the upper surface of the flat plate 21, a convex portion, that is, a relatively large stone 23, disposed between adjacent depressions (algae growing plate 6) is disposed. This stone 2
The flat plate 21 including No. 3 can be relatively easily manufactured by using a mold material made of a known thermoplastic elastomer (rubber elastic body) proposed by Sumitomo Osaka Cement Co., Ltd. described above.

The substantial overhang formed by the lower half of the relatively large stone 23 forms a virtual recess 22 (FIG. 8) in cooperation with the plate 21 as best seen in FIG. Has formed. The concave portion 22 is used for evacuation of a young shellfish or a young shellfish from a natural enemy, and it is preferable to select an original natural stone so that the height of the opening is about 50 mm.

As shown in FIG. 7, gravel 24 may be scattered in other areas on the upper surface of the flat plate 21, that is, other than the area occupied by the stones 23 and the algal growing plate 6. The breeding reef 20 including the stones 23 and the gravel 24 is formed by pouring concrete into the mold material made of the thermoplastic elastomer (rubber elastic body) described above, whereby the flat plate 21, the stones 23 and the gravel 24 are formed.
Can be integrally manufactured.

Although the first and second embodiments have been described as preferred embodiments of the present invention, a concrete for forming the shellfish reefs 1, 20 and the stone 23 is common to these two embodiments. There is an advantage that the use of concrete mixed with calcined diatomaceous earth powder can reduce the influence of the alkali on the ecosystem and can quickly create a favorable biological environment after installing the shellfish reef 1. In addition, for example, calcined diatomaceous earth powder generated in the finish molding step after calcination of a baked product such as a brick baked at 800 ° C to 900 ° C diatomaceous earth buried in a large amount in Noto Peninsula has been discarded, By reusing this, resources can be used effectively. In this case, if the concrete is produced by mixing a calcined diatomaceous earth powder in an amount that replaces a part of the cement (for example, 10 to 30 wt%), the amount of cement, which is a fundamental cause substance of the alkali problem, is reduced. There is an advantage that it can be substantially reduced.

Shellfish reefs 1, 20 of the first and second embodiments
Before installing this on the seabed, typically, an algal growing plate 6 on which intermediately grown seaweeds are propagated is attached, and then installed on the seabed in a predetermined sea area. Upon installation on the seabed, the adjacent shellfish reefs 1 and / or 20 may be arranged adjacent to each other, or may be arranged apart from each other.

By arranging the shellfish-growing reefs 1 and / or 20 on the sea floor in this manner, this sea area can create an environment where seaweeds serving as baits for shellfish such as abalone are established. Therefore, then, it is only necessary to release juveniles or young shellfish such as "Ezo abalone" into this sea area. In order to prevent damage to larvae or octopus, which is a natural enemy of larvae,
A fence surrounding the plurality of shellfish reefs 1 and / or 20 may be provided. The fence may entirely surround a fishing ground for shellfish formed by installing the shellfish reef 1 and / or 20, and may also divide the fishing ground into a plurality of areas, A fence surrounding the section may be provided for each section. In addition, each shellfish growing reef 1 or 20 may be individually surrounded by independent fences.

In the sea area where the shellfish reefs 1 and / or 20 are to be installed, it is preferable to select a place having a water depth of about 1 to 3 meters, particularly for growing young or young shellfish of "Ezo abalone". Good. There is data that such a relatively shallow water area is more favorable for the growth of juvenile or young shellfish of "Ezo abalone" than a deeper sea area. Also,
In such relatively shallow waters, shellfish reefs 1 and / or
Or, if you set 20 and make a fishing ground for shellfish, it is preferable to set the height of the fence described above to be almost the same as the water depth in order to protect the juveniles or young shells from natural enemies, The work is relatively easy. The fence may be composed of concrete walls, but a plurality of upright supports fixed to the shellfish reef 1 or 20 or the seabed shall be provided, and a wire mesh or a net made of synthetic fiber or natural fiber shall be attached to this support. It is advantageous in terms of cost to construct the fence by using. The net means formed of such a net preferably has an eye size that makes it difficult for an octopus grown to some extent to pass through.

A plurality of shellfish-growing reefs according to the present invention are installed in a sea area where abalone naturally breeds, or in a sea area where it was previously considered not to be an abalone fishing ground because of insufficient seaweed to feed. Then, it is used for raising the released mussels or larvae. The released larvae or larvae are attached to the wall of the breeding reefs 1 and 20 and grow while eating the seaweed on the plate 6. You can protect yourself by running away.

When the seaweed on the plate 6 is reduced or attenuated, for example, by being eaten by abalone, the plate 6
Can be removed from the shell reefs 1 and 20 and replaced with a new plate 6 to which seaweed is attached. Thereby, a sufficient amount of food can be constantly replenished for the abalone. When the abalone has grown to such an extent that it can be harvested, the abalone can no longer penetrate into the recesses 8 and 22 and is attached to the outer walls of the shellfish reefs 1 and 20. It is easy to capture.

[Brief description of the drawings]

FIG. 1 is a perspective view of a shellfish reef of a first embodiment.

FIG. 2 is a plan view of the shellfish reef of FIG. 1;

FIG. 3 is a side view of the shellfish reef of FIG. 1;

FIG. 4 is a partial side view in which a portion indicated by an arrow IV in FIG. 3 is extracted and enlarged.

FIG. 5 is a partial side view in which a portion indicated by an arrow V in FIG. 3 is extracted and enlarged.

FIG. 6 is a perspective view of a shell reef of the second embodiment.

FIG. 7 is a plan view of the shell reef of FIG. 6;

FIG. 8 is a partial side view of the shellfish reef of FIG. 6;

[Explanation of symbols]

 1,20 Shellfish cultivation reef 4 Upper block (convex part) 6 Plate for algae cultivation 8,22 Concavity 23 Concrete stone

Claims (12)

[Claims] 1. A shellfish raising reef comprising: a mounting seat for detachably fixing a plate to which seaweeds are attached; and a recess for evacuation of juvenile shellfish or juvenile shellfish from natural enemies. . 2. The shellfish growing reef according to claim 1, wherein the shellfish growing reef has a lateral surface extending in a lateral direction, and the mounting seat is formed on the lateral surface. 3. The lateral surface has a convex portion protruding vertically from the lateral surface, and the convex portion has an overhanging portion whose upper part is protruded more outward than its lower part. The shellfish reef according to claim 1, wherein the recess is formed in a portion shaded by an overhang portion. 4. The shellfish breeding reef according to claim 3, wherein the convex portion is made of a concrete lump, and at least a part of the convex portion has an unevenness obtained by transferring an uneven rock surface of natural rock. . 5. The shellfish raising reef according to claim 3, wherein the recess is formed by a lower surface of the convex portion and the lateral surface. 6. The shellfish growing reef according to claim 1, wherein the shellfish growing reef is made of concrete containing calcined diatomaceous earth powder. 7. A step for preparing a shellfish-growing reef comprising: a mounting seat for detachably fixing a plate to which seaweed is attached; and a recess for evacuation of juvenile shellfish or young shellfish from natural enemies. Fixing the plate with the attached to the mounting seat of the shellfish reef, installing the shellfish reef on the sea floor, and throwing a juvenile or young shellfish in the sea area where the shellfish reef was installed. Shellfish growing method including. 8. The method according to claim 7, further comprising a step of replacing the plate fixed to the mounting seat with another plate to which seaweed is attached when the seaweed has declined. 9. The shellfish growing method according to claim 7, wherein the depth of the seabed where the shellfish growing reef is installed is 1 to 3 m. 10. The method according to claim 7, further comprising a step of enclosing the shellfish-growing reef set on the seabed with a natural enemy intrusion prevention fence.
The method for growing shellfish according to any one of the above. 11. The shellfish growing method according to claim 10, wherein the natural enemy invasion preventing fence has a height substantially equal to the depth of the seabed on which the shellfish growing reef is installed. 12. The shellfish growing method according to claim 10, wherein said natural enemy intrusion prevention fence is constituted by net means.