JPH0210937Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a block for fish reefs, and in particular to a block for fish reefs that has a surface structure that facilitates the generation of vortices and upwelling currents when installed on the seabed, and that is difficult to sink or bury on the seabed. .

Conventionally, a fish reef block 1 having a surface structure as shown in FIG. 1 has been used to expand coastal fishing grounds and cultivate fishing grounds as the number of distant sea fishing grounds decreases. However, when such a reef block is installed on the seabed and the tidal current hits the front of the reef, part of it flows upward as an upwelling current, as shown by the arrow in Figure 2, and the rest flows upward. It turns toward the ocean floor, turns around, and returns on the ocean floor in the opposite direction. If this flow toward the seabed continues, the seabed will gradually be eroded and gouged out by the current, as shown in Figures 2 and 3, and as shown in Figure 2, 4, the seabed will gradually become closer to the reef. The bottom of the seabed has been extensively scoured, causing the installed fish reef to tilt and slip into the hole created by the scour. When this situation is repeated, a large part of the fish reef becomes buried under the seabed, and the reef no longer functions as a fish reef.

Furthermore, when the current hits a protrusion such as a reef on the seabed, a vortex is generated behind the protrusion. Plankton, which is food for fish and shellfish, moves along with the currents, and many of them are suspended in these eddies.
Fish and shellfish gather near these eddies, and even when using reef blocks, it is necessary to generate the eddies in as wide a range as possible.

However, as shown in Figure 3, the conventionally used box-shaped reef block has the disadvantage that the current flows relatively smoothly around it, and the generation of the above-mentioned eddies is small. was.

This idea was created in view of the above-mentioned problems in the past, and its purpose is to:
To provide a fish reef block that is difficult to scour the seabed ground by tidal currents when it is installed on the seabed, prevents it from being buried in the seabed, and is capable of generating eddy currents over a wide range. It's about doing.

In order to achieve this object, the present invention provides a fish reef block which has a bottom plate and four side plates and is box-shaped as a whole and is formed into a planar structure, and the bottom plate is a bonded portion between each side plate and the bottom plate. The bottom plate has an overhanging portion formed on the outer periphery of the bottom plate, and both ends of each of the side plates extend outward beyond the adhesive portions of the adjacent side plates and are substantially perpendicular to each other. By forming a pair of side walls, each corner of the side plate is provided with a void space.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

As shown in FIG. 4, the fish reef block 2 according to this embodiment is formed into a box shape and is composed of a square bottom plate 3 and a side plate 4.
Openings 5 are provided in the and side plates 4, respectively. Further, the bottom plate 3 extends outward beyond the bonded portion 6 between each side plate 4 and the bottom plate 3, and has a projecting portion 7 formed with a predetermined width on the outer periphery of the bottom plate 3. Both end portions 4a and 4b of the side plate 4 extend outwardly from the bonded portion 8 with the side plate 4 adjacent to each other, and each corner of the reef block 2 has a cross section L.
A void space 11 is provided by forming a pair of side walls 9 having a character shape.

When using the reef block 2 constructed in this way, select a relatively flat seabed near the coast, and suspend and install the reef block 2 into the sea using a crane so that it touches the bottom with the bottom plate 3. do.

When the reef block 2 according to this embodiment is used, since the protruding portion 7 is formed with a predetermined width on the outer periphery of the bottom plate 3, the tidal current flows around the reef block 2 as shown in FIG. Even if a part of the tidal current hits one of the side plates 4 and reverses toward the seabed, the overhang 7 will block the tidal current, and the tidal current will not directly hit the seabed base 10, preventing the reef from flowing. Block 2
The seabed ground around the area will no longer be gouged out by tidal currents. Therefore, a hole is not created near the fish reef block 2 due to extensive scouring of the seabed ground, and a situation in which the fish reef slides into the hole and is buried in the seabed is prevented. becomes possible. Furthermore, since a space 11 formed by a pair of wing walls 9 is provided at each corner of the reef block, the flow of seawater collides with the wing walls 9, as shown in FIG. In addition to generating a rising flow within the space 11, the flow that goes around the end of the sleeve wall 9 generates a vortex behind the sleeve wall 9. Furthermore, since the voids 11 are provided at each corner of the box-shaped block, it is possible to reliably capture the complicatedly changing flow of seawater and generate upwelling currents and eddy currents.

In this embodiment, an example in which openings are provided in the side plates and the bottom plate is used.
The structure is not limited to this embodiment, and may be one in which no opening is provided. Furthermore, although this embodiment has been described using an example in which the side and bottom plates of the reef block are formed in square shapes, the present invention is not limited to this embodiment in any way.

Because the present invention has the above-mentioned configuration, it is possible to alleviate the erosion of the seabed caused by the tidal current hitting the fish reef and gouging the seabed, and as a result, the fish reef is buried in the hole created in the seabed due to erosion. It is possible to prevent the situation where the reef becomes unusable as a fish reef due to the damage, and it is possible to maintain its function as a fish reef for many years. In addition, since a void formed by a pair of wing walls is formed at each corner of the reef, it is possible to generate a large amount of upwelling current within this void, and also to generate vortices behind the wing walls. It is possible to reliably capture seawater flows that are easy to occur and that change in a complicated manner. In addition, because the wing walls protrude outward from the side panels of the reef, vortices are generated over a wide area, making it easier for plankton to gather and attracting many fish, making it possible to increase fishing efficiency.
This effect is achieved.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a conventionally used reef block, and Fig. 2 shows that when a conventionally used reef block is used, the seabed is scoured by the current, and the reef block is removed from the seabed. FIG. 3 is a plan view showing the eddy current state that occurs when a conventional fish reef block is used, and FIG. Fig. 5 is a side view showing the current state when the reef block according to the present invention is used, and Fig. 6 is a perspective view showing the current state when the reef block according to the present invention is used. FIG. 2...Fish reef block, 3...Bottom plate, 4...Side plate, 7...Protruding portion, 6, 8...Adhesive portion, 9...Sleeve wall.

Claims (1)

[Scope of Claim for Utility Model Registration] In a fish reef block that has a bottom plate and four side plates and is box-shaped as a whole and formed in a planar structure, the bottom plate is located outwardly from the bonded portion between each side plate and the bottom plate. A projecting portion is formed on the outer periphery of the bottom plate, and a pair of substantially orthogonal projecting portions are provided at both ends of each of the side plates, each extending outward from the bonded portion with the adjacent side plate. A block for a fish reef, characterized in that a space is provided at each corner of a side plate by forming wing walls.