JPH0365735B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves releasing protected and raised young fish into the ocean,
This relates to a marine farm fence mainly for bottom-layer fish, which is arranged around a marine farm where fish are grown in a state almost like that of a natural fish by partial feeding, so that they can easily enter from the outside and are difficult to come out from the inside.

[Prior art]

Although it has not been long since the shift from aquaculture to marine farms that release fish into the ocean that are similar to wild fish, marine farms for red sea bream using acoustic feeding methods are already being used in the experimental stage.

However, it is not possible to build a fence around the ocean ranch area.

The reason for this is that simply building a fence would create a situation where wild sea bream etc. would not be able to enter the marine farm, and the area would no longer be a fishing ground for wild sea bream, which is not a good idea.

Therefore, it is desired to develop equipment that allows wild sea bream and the like to freely enter the marine pasture inside the fence from outside the fence, while preventing stocked sea bream and the like that are being reared inside the fence from leaving the fence.

In other words, the red sea bream raised on current marine farms is
For red sea bream that are still small and in their first or second year, acoustic feeding has a certain effect, so there is no particular problem without a fence, but when red sea bream are in their third year or more, they return to their original characteristics and scatter into the open sea. Due to the circumstances,
The recovery rate is extremely low, and there is a fear that the project as a whole may not be viable, so the realization of the marine farm fence as described above is desired.

However, when installing fences around such marine farms, it is necessary to avoid being affected by sea conditions such as waves, and it is also necessary to prevent them from interfering with the navigation of ships.

[Purpose of the invention]

The present invention was made in response to the above-mentioned current demands in marine farms, and allows natural benthic fish to freely enter the fence from outside the fence provided around the marine farm, and also allows natural bottom fish to enter the fence from outside the fence. Marine farm fences that prevent released bottom layer fish, such as red sea bream, striped mackerel, flatfish, mackerel, prawns, etc., as well as natural bottom layer fish once they have entered the fence, are protected against the effects of waves. The purpose of this system is to increase the amount of fish caught at marine farms and improve the recovery rate by installing them in a manner that does not interfere with ship navigation.

[Structure of the invention]

To achieve the above object, the marine farm fence of the present invention is a net-like fence provided around a marine farm mainly for rearing bottom-layer fish, by attaching a weight such as a continuous steel chain to the bottom end of the net-like fence. The net fence is placed in close contact with the seabed, and its upper end is maintained at a predetermined height in the water by attaching floats such as foamed polystyrene, and is arranged in a zigzag shape on a plane at appropriate intervals, and the zigzag mesh fence. It is characterized by having a funnel-shaped opening that tapers inward toward the inside of the sea farm.

The marine farm fence constructed in this way has a zigzag-shaped bent part formed in the short net-like fence with particular focus on the characteristics of bottom-layer fish, which has a shape that allows natural bottom-layer fish to easily enter from the outside and prevent them from coming out from the inside. The funnel-shaped opening makes it difficult for stocked bottom fish that are being reared to come out from inside the fence, and natural bottom fish from the open sea can easily get inside, and even natural bottom fish once inside. Since they are less likely to come out, the amount of fish caught after breeding will increase.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a marine farm fence according to an embodiment of the present invention, and FIG. 2 is an enlarged side in the A-A direction of FIG. 1. 3 is an enlarged side sectional view taken along the line B--B in FIG. 1.

This marine farm fence is installed around a marine farm where raised young fish are released and grown up to the point where they can be caught, and as shown in Figures 1 and 2, the fence is mainly made of a fishing net 6 made of chemical fiber or the like. mesh fence 1
0, and by attaching a weight 7 such as a continuous steel chain or beaded lead to the bottom end of the mesh fence 10, it is brought into close contact with the seabed B, and the bottom end of the mesh fence 10 is brought into close contact with the seabed B. A bead-shaped float 5 made of styrofoam or the like is attached to the upper end, and sinkers 3 are attached at appropriate intervals to prevent the mesh fence 10 from being washed away by ocean currents and lying on the seabed B.
and is holding the stay with stay rope 4.

Here, the upper end of the mesh fence 10 is designed based on consideration of the vertical movement range from the seabed B of the stocked bottom layer fish _F It is determined by the height position H in the water.

Next, this net fence 10 is arranged in a zigzag shape on a plane at appropriate intervals as shown in FIG. Arrow Y on the broken part
Natural benthic fish F _Y shown in white in the outer diagram shown in
A funnel-shaped opening 2 that tapers inward is provided inside the arrow X so that the opening 2 can be inserted therein.

This opening 2 is located at the arrow Y as shown in FIG.
It has a funnel-like structure that allows natural bottom-layer fish F _Y to enter easily, so once inside, it is difficult to get out.

The bottom end of this funnel-shaped opening 2 is connected to the weight 7 which is in contact with the seabed, and the bottom end of the exit is connected to the floating body 9, rope 12, aggregate 13 and sinker 3 as appropriate. The funnel-like part has a structure in which it is placed at an appropriate height above the seabed B, and the bottom of the funnel-shaped part is a plate-like structure 8 with an appropriate number of small holes, and the upper part is a net-like structure 11.

By installing the marine farm fence with the above configuration between the inside of the marine farm indicated by _arrow Due to the habits of the fish, it is rare for the fish to climb over the mesh fence 10 of a predetermined height and go outside of the arrow Y, and can be kept completely within the marine farm fence.

In addition, after the natural benthic fish F _Y on the open sea side gather on the inside part of the zigzag mesh fence 10,
They enter the fence through the funnel-shaped opening 2, but once they have entered, it is difficult to come out to the open sea again, so they are kept inside the fence.

Furthermore, since the mesh fence 10 is installed in a low profile on the seabed B, it is hardly affected by sea conditions such as waves, and does not affect the navigation of ships at all.

〔Effect of the invention〕

As described above, in the marine farm fence of the present invention, an underwater mesh fence of a predetermined height that can stop the movement of bottom fish is arranged in a zigzag shape on the seabed, and inside the zigzag mesh fence. There is a funnel-shaped opening that allows natural benthic fish from the outside to easily enter the seabed of the broken part, and prevent them from coming out from the inside, so natural benthic fish from the outside will naturally swim along the fence. They will gather at the funnel-shaped opening, and conversely, even if the bottom fish released inside swim along the mesh fence, the opening protrudes inward, so they will not come out to the outside. A leopard structure fence will be built around the ocean farm.

Therefore, if the fence of the present invention is installed around the sea area of the marine farm, the stocked bottom fish in the marine farm will not go outside the fence, and the problem of poor recovery rate of adult fish after rearing can be completely solved. Since natural benthic fish from outside the fence can freely enter the fence, the sea area inside the marine farm can be used as a fishing ground for wild fish, just as it was before the fence was built.

In addition, since the fence of the present invention is installed low on the seabed, it is hardly affected by sea conditions such as waves, and has the great advantage of not affecting the navigation of ships at all. be.

Note that the present invention can be particularly effectively applied to marine farms for bottom-layer fish.

[Brief explanation of drawings]

FIG. 1 is a plan view of a marine farm fence according to an embodiment of the present invention, FIG. 2 is an enlarged side sectional view taken along A-A in FIG. 1, and FIG. 3 is an enlarged side sectional view taken along B-B in FIG. 1. FIG. 2 is an enlarged side sectional view. 2...opening, 6...fish net, 10...mesh fence,
B: Seabed, H: Underwater height position, X: Inside.

Claims (1)

[Claims] 1. Net fences to be installed around marine farms are placed in a zigzag pattern on a plane at appropriate intervals, with the bottom end submerged in the seabed and the top end maintained at a predetermined height underwater. , A marine ranch fence with a funnel-shaped opening that tapers inward on the inside of the folded part of the zigzag-shaped fence.