JPH0427334Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a connecting block for small fish nests.

[Background Art] In recent years, as river maintenance is progressing through public works projects, connection blocks for bank protection have been frequently used on riverbeds and slopes for the purpose of bank protection.

However, although these revetment blocks are very effective in terms of flood control, they create an extremely unsuitable habitat for creatures living in the river, as there are no resting places for fish or spawning areas.

Under such circumstances, calls for protection of the natural environment have been growing in recent years, and in response, various types of fish nest blocks have been developed, and efforts have also begun to be made to construct fish passages and form fish nests using foot protection blocks. There is.

For large rivers, the above-mentioned methods can be expected to be effective, but recently there has been an urgent need to protect the nature of small waterways such as agricultural drainage canals.

[Problems to be solved by the invention] The conventional techniques described above had the following problems.

The above agricultural drainage canals, which are generally called clear culverts, have a small cross section, so the entire surface is often made up of block revetments, which creates an unsuitable natural environment.

Moreover, because of their small cross-section, it is difficult to maintain fish nests as mentioned above due to land issues.Also, unlike the maintenance of general rivers, the entire amount is not borne by the government, but is borne by the beneficiaries, so it is difficult to maintain fish nests as much as possible at a lower cost. Because of this, it is difficult to budget for the purpose of constructing fish nests, which is different from the original purpose of drainage canals, and nature conservation tends to be neglected.

In addition, conventional fish nest blocks
Many of them are designed for raw fish over 10 cm.
The fish nest space is too large for small fish living in small waterways.
It cannot become a suitable fish nest.

Also, when considering the biological system of living things, there is a law of nature in which parents give birth to children, and the children grow up to become parents, and give birth to children again.However, when considering the natural environment, there is a law of nature in which parents give birth to children, children grow up to become parents, and give birth to children again. It is meaningless unless you also consider the environment in which you will be doing it.

The habitat for eggs and fry must be inaccessible to large fish that feed on them, and must be in a dark place with gentle currents.

This proposal has been developed in view of the problems of the prior art, and its purpose is to provide something that can do the following.

That is, the present invention can be installed in the same way as conventional small connecting blocks, and can be installed at low cost while solving the above-mentioned problems without providing a special fish nest space.

[Means for Solving the Problems] In order to achieve the above object, the present invention is as follows.

That is, in the present application, a horizontal hole for a fish nest is penetrated through the center of the side surface of the block main body configured like a convex connecting block for a seawall, and a hole extends from the horizontal hole for the fish nest to the bottom of the block main body. This is a connecting block for small fish nests with an appropriate number of vertical holes for eggs and fry.

[Function] It is laid in the same manner as the known convex type seawall connecting block.

In the figure, 6 is a flat block and 7 is a water level line.

[Example of idea] Examples will be described with reference to the drawings.

1 is a connecting block for a small fish nest according to the present invention.

Reference numeral 2 denotes a block main body having a structure similar to that of a conventionally known convex type seawall connecting block, and is composed of a base 2A and a protrusion 2B projecting from the upper surface of the base.

Reference numeral 3 designates a horizontal hole for a fish nest, which is penetrated through the center of the side surface of the block body 2.

Reference numeral 4 denotes copper-containing wire connection holes which are passed through the horizontal hole 3 for the fish nest in parallel with the horizontal hole 3 for the fish nest at left and right positions.

Reference numeral 5 designates a suitable number of vertical holes for eggs and young fish, which are passed through the horizontal hole 3 for the fish nest from the horizontal hole for the fish nest to the bottom of the block body.

The horizontal hole for the fish nest was preferably about 10 cm in diameter, and the vertical hole for the eggs and fry was about 5 cm square.

This fish nest hole is 10 cm long and lives in small waterways.
This is a place where the following young fish can easily enter, rest, and spawn.

In addition, the vertical holes for eggs and fry are divided into small sections to prevent adult fish from entering, so that the eggs and fry do not become food for other fish. Because there is no water, the water remains in a suitable state and becomes a living space for eggs and young fish.

Note that the shape of the convex portion of the block is not limited to the shape of the present invention, but can be the same shape as various existing convex blocks depending on the river conditions.

By changing the size of the block, it is possible to target not only young fish of 10 cm or less, but also adult fish, but a vertical hole for eggs and fry of about 5 cm square is appropriate.

[Effects of the invention] Since the present invention is configured as described above, it produces the following effects.

A: When the blocks of this plan are laid out, this side hole for the fish nest will become a space for adult fish.

In this case, about half of the horizontal hole 3 for the fish nest will be hidden, but ideally the entrance 3A of the horizontal hole for the fish nest is small enough for fish to enter and exit, and that there is some space inside.

In addition, since the horizontal hole for the fish nest is opened in a direction perpendicular to the flow direction, the water flow does not directly turn into a rapid stream and enter the hole, so that appropriate reflux is achieved.

This sends oxygen into the fish nest and prevents it from turning into dead water, and also serves to prevent sediment from accumulating in the vertical holes for eggs and fry.

B. The vertical hole for eggs and fry serves as a spawning bed and a place for the fry to hide.

C By penetrating the lower part of the block with vertical holes for eggs and fry, underground water flowing at the lower part of the block can be drawn into the fish nest, increasing the supply of oxygen.

[Brief explanation of drawings]

Fig. 1 is a side view, Fig. 2 is a plan view, Fig. 3 is a front view, Fig. 4 is a sectional view taken along line A-A, Fig. 5 is a longitudinal sectional view of a general agricultural drainage canal, and Fig. 6 is a longitudinal sectional view of a general agricultural drainage canal. The figure is a plan view of the same as above, FIG. 7 is an enlarged vertical cross-sectional view of a main part to explain the function, and FIG. 8 is a perspective view to explain the function. 1... Connection block for small fish nest, 2... Block body, 3... Horizontal hole for fish nest, 4... Copper-containing wire connection hole, 5... Vertical hole for eggs and fry.

Claims (1)

[Scope of utility model registration request] A horizontal hole for a fish nest is penetrated through the center of the side surface of the block body, which is configured like a convex connecting block for a seawall, and a vertical hole for eggs and fry is inserted into the horizontal hole for the fish nest and extends from the horizontal hole for the fish nest to the bottom of the block body. A connecting block for a small fish nest, characterized by having an appropriate number of holes penetrated through the block.