JP2002262701A - Net for protection of benthos - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively protect benthos from sludge attributable to human domestic wasted water. SOLUTION: This net for protection of benthos is installed in the vicinity of bottom of the water (1) approximately parallel to the bottom and set to vibrate the body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a net for protecting benthic animals in a sea or lake.

[0002]

2. Description of the Related Art A variety of benthic animals such as sponges, silkworms, hydras, oligochaetas, and shellfish inhabit the sea or lakes.

[0003] In recent years, as a large amount of human wastewater has flowed into the sea or lake, sludge resulting from the domestic wastewater has been deposited on the bottom of the water. Such sludge has an adverse effect on benthic animals and may kill the benthic animals.

[0004] However, there is no known means for effectively protecting benthic animals from such sludge.

[0005]

Under these circumstances, the present invention has been made to provide a means for effectively protecting benthic animals from sludge caused by human wastewater. is there.

[0006]

Means for Solving the Problems In order to solve the above problems, the present inventors have made intensive studies and as a result, arranged a net near the water bottom so as to be substantially parallel to the water bottom, and shake the net. By moving the sludge, it was found that sludge deposited on the water bottom was washed off by ocean current or water current. That is, the present invention provides the following benthic animal protection means.

(1) A benthic animal protection net characterized in that a net is disposed near a water bottom so as to be substantially parallel to the water bottom, and the net is rocked. .

(2) The mesh body is provided with a float at an upper portion and supported by a plurality of cords having a lower end fixed to a water bottom,
The net body swings through the cord body by the force of the wave (claim 2).

[0009]

According to the first aspect of the present invention, when a net disposed near the water bottom and substantially parallel to the water bottom is swung, the sludge deposited on the water bottom is caused to flow offshore by an ocean current or a water current. It is not always clear to the inventor why the sludge on the water bottom is swept offshore by the ocean current or water current by oscillating the net body near the bottom of the water. Alternatively, it is considered that the natural purifying action inherent in the lake is promoted, and the sludge below the net disappears. As shown below, in the test by the present inventors, it was confirmed that the sludge below the mesh disappeared in a short period of time by swinging the mesh near the water bottom.

[0010] When the float swings by the force of the wave, the swing is transmitted to the net through the cord. Thus, since the lower end of the cord body is fixed to the water bottom, the net body swings substantially parallel to the water bottom. That is, when the water bottom is substantially horizontal, the net body swings in a substantially horizontal direction.

[0011]

Next, embodiments of the present invention will be described with reference to the accompanying drawings. In the benthic animal protection net according to the present invention, the net 3 is disposed near the water bottom 1 so as to be substantially parallel to the water bottom 1, and the net 3 is swung. The mesh body 3 is formed by carbon fiber as an example.
The net 3 is, for example, 2 cm × 2 cm by a 1 cm thick cord.
The thing which forms many meshes of 10 cm X 10 cm is used. The distance between the net 3 and the water bottom 1 is, for example, 20 to 30 cm. The size of the net 3 is, for example, 2 m × 2.
m to 10 m × 10 m.

The net 3 is provided with a float 5 on the upper part and supported on a plurality of cords 9, 9,... 9 to swing mainly in a direction substantially parallel to the water bottom. The string body 9 is a nylon string having a thickness of 1 cm as an example,
A plurality of floats 5, 5,... Each float 5 is, for example, a hollow sphere made of polypropylene having a diameter of about 10 to 60 cm. FIG. 3 shows the state of the floats 5, 5,... When the water depth becomes shallower than in FIG. The reference numeral 11 indicates an auxiliary cord. In addition, what is shown with the code | symbol 13 is the sludge deposited on the water bottom 1. FIG.

[0013]

Example: 10cm with a 1cm thick carbon fiber cord
A 5mX5m square net formed by forming a large number of X10cm nets was prepared. On the other hand, 1 cm thick with three polypropylene hollow spheres with a diameter of 30 cm attached to the upper part,
Four nylon string bodies each having a length of 1 m were prepared. The four corners of the net were fixed to these strings, and a 1 cm thick nylon auxiliary string was attached between the strings and the net. In the sea at a depth of about 1m, where sludge caused by domestic wastewater is constantly deposited on a substantially horizontal bottom, the lower end of each string is fixed to the bottom, and the net is substantially parallel to the bottom and the net and the bottom are connected. Was set to be 20 cm.

When the water bottom below the net was examined two weeks after the installation of the net, the sludge deposited on the water bottom below the net had disappeared.

[0015]

According to the first aspect of the present invention, when a net disposed near the water bottom and substantially parallel to the water bottom is swung, the sludge deposited on the water bottom is caused to flow offshore by an ocean current or a water current. That is, benthic animals are effectively protected from sludge caused by human wastewater, and the habitat of benthic animals is improved.

[Invention of claim 2] When the float swings by the force of the wave, the swing is transmitted to the net through the cord. That is, the net body constantly swings near the bottom of the water. Therefore, the sludge deposited on the water bottom is effectively eliminated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a benthic animal protection net according to the present invention is attached to the sea.

FIG. 2 is a front view showing the same benthic animal protection net.

FIG. 3 is a front view showing the benthic animal protection net in a state where the water depth is shallower than that in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water bottom 3 Net 5 Float 7 Lower end 9 String 11 Auxiliary string 13 Sludge

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Mitsuo Endo 13-11 Mimondai, Shimizu-shi, Shizuoka F-term (reference) 2B104 AA22 AA38 BA13 CC35 CG26 FA15 FA18 4D059 AA09 AA30 CB01 CB27 CB30

Claims (2)

[Claims] 1. A benthic animal protection net, wherein a net is disposed near a water bottom so as to be substantially parallel to the water bottom, and the net is swung. 2. The mesh body is provided with a float at an upper portion and supported by a plurality of strings fixed at a lower end to a water bottom, so that the mesh swings through the strings by the force of a wave. The benthic animal protection net according to claim 1, wherein: