JPH026776Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a trawl net that has a sorting function to catch only targeted fish.

A trawl is a type of bottom trawl net with a sleeve net attached to the front of a bag-shaped body net, and is used to catch fish by widening the net opening and dragging the net. However, it is difficult to catch them, and the major issue with this fishing method is how to prevent them from being caught.

Traditionally, from the perspective of protecting marine resources, it was desirable not to catch small fry, but only those that had grown to a certain size, or to select and catch only flat-shaped fish while letting spindle-shaped fish escape. Even in the case of fish, it has not been possible to achieve effective selective fishing simply by adjusting the mesh size of the net to a larger size, and a certain amount of bycatch has traditionally been considered unavoidable. However, in recent years, as countries have declared exclusive economic zones (the 200 nautical mile issue) and regulations on marine resources have been implemented, bycatch has become a serious international fishing problem.

For example, in recent years the United States has strictly regulated fishing quotas for foreign cod in the 200-mile inland waters (Bering Sea, Gulf of Alaska waters), but the Bering Sea area is also home to many sablefish, the main target fish species. Japanese fishing boats have been fishing for flounder for a long time. However, when fishing for flounder using trawl nets in this area, a considerable amount of sablefish is caught as bycatch, and as a result, the quota for sablefish is being used up, and if this trend continues, it will not only put pressure on operations, but also lead to early closure of the fishery. We are in a situation where something could happen. Each fishing company and each vessel is taking various measures to prevent bycatch, but no satisfactory countermeasures have yet been found. Another example is the by-catch of snow crabs, which are prohibited from being caught in flounder fisheries, which has become a problem.

Conventionally, according to a trawl net consisting of four sheets as shown in FIG.
As shown in the figure, it is formed into a semi-cylindrical shape and its rear end is sewn 9 in the shape of a single letter using large sesame seeds or wire, or the rear end of the dotted part 8 is sewn into a single character shape. If the shape is such that the eyes are closed toward the center point of 10, bycatch cannot be prevented.

Especially during operation, as the trawl net is pulled forward in the water, water resistance concentrates on the seam 9 and the closed seam 10, causing the seam of the knotted part 8 to become more and more folded. There was a problem that it closed in a long and narrow manner, making it difficult for fish to escape. For this reason, it has been found that even if the hollow part of the trawl net is formed into a semi-cylindrical shape so that the mesh size is larger than the size of the fish, the fish do not easily escape and bycatch cannot be prevented.

The present invention attempts to eliminate the above-mentioned drawbacks, and aims to achieve selective fishing as much as possible by improving the closed portion of the trawl net.

Hereinafter, the present invention will be described in detail based on illustrated embodiments. This example is an example of an improvement of a trawl net for selecting sablefish catches in flounder fishing. Figure 1 shows the main target fish species, Japanese flounder 1, and Figure 2 shows the bycatch fish, sablefish 2.
The former type, the Japanese flounder 1, has an oblong body shape with a laterally flattened body, and the body length is 30 cm to 80 cm, which is economical.
It is. On the other hand, the latter, Sablefish 2, has an elongated cylindrical shape with no flattened sides and a body length of 60 to 80 cm.

On the other hand, as shown in FIGS. 5 and 6, the trawl net for Japanese flounder consists of left and right sleeve parts 3, 3', left and right side parts 4, 4', a square part 5, a batting part 6, and a batting part 6. a beret part 7 corresponding to the part 6; the batting part 6 and the beret part 7;
It consists of batted parts 8, 8', 8'' attached to the rear end, and the netting of the batting part 6, beret part 7, and batted parts 8, 8', 8'', 8 was conventionally made of dark green strong They used 285 threads woven at a pitch of 90 m/m, but in this case, not only the sablefish 2, but also most of the other fish were caught there, resulting in severe bycatch. Therefore, the inventor used black strong thread 380° / 600 threads to adjust the texture of the knotted part 8.
I made a big adjustment to 200m/m and tried to get Sablefish 2 through.

In the present invention, the rear end of the conventional knurled part 8 is formed into a semi-cylindrical shape, and the rear end of the knurled part 8 is formed into a bag net-like shape with appropriately sized openings adjusted to a large diameter. Cap 1 formed by
1 is provided at the rear end of the knurled portion 8 to make it easier to see. This cap 11 has a bag mesh shape like a hat, and when it is being dragged, water resistance is applied almost uniformly to the entire bag net, and each mesh is pulled evenly in all directions, making it look like a parachute underwater. It is installed so that it opens in a state close to the open state. Therefore, when seine-seining, the size of the mesh is at its widest, so sablefish 2 and small fish smaller than the specified size will slip out, making it possible to prevent bycatch as much as possible.

Next, the inventor formed the rear end of the crossed section 8 into a semi-cylindrical shape, and prepared and attached three kinds of closed caps 11 in the shape of a bag net about 1 m in length thereto. In addition, the joint between the kotsudo part and the kotsudo cap is made by passing a large sesame seed or wire through both sides and shackle the sides. The specifications of the cap in the embodiment are as follows.

(B) 210 polyethylene threads with a mesh size of 180m/m (B) 488 polyethylene threads with a mesh size of 165m/m (C) 488 polyethylene threads with a mesh size of 135m/m (B) When using a knotted cap There were no sablefish mixed in at all, but of the other fish, only extremely large fish remained. However, the number of threads was small and I was worried.

In the case of (b), 2 to 3 sablefish were mixed in, and the other fish remained small in size.

In the case of (c), the eyes were small and most of the sablefish 2 and the other fish stayed there.

From the above results, it has been found that the optimum size for preventing the by-catch of sablefish 2 in the flatfish 1 fishing is when the cap 11 of (b) is used.

Next, we experimented with the present invention to prevent bycatch of small crabs such as small crabs, such as small crabs, and snow crabs. Scarlet flounder 12 has an oblong shape with a length of 25 to 30 cm, and its width is about 60% of its body length (15 to 18 cm).
To catch this fish, we used 488 or 600 Kotsudo Caps 11 and formed the catch to 135 m/m. As a result, only 12 types of small crabs remain, and 13 species of small crabs have disappeared, and they are rarely caught as bycatch.

As mentioned above, the present invention includes the left and right sleeve parts 3, 3', the left and right armpit parts 4, 4', the skier part 5, the batting part 6, and the beret part 7 corresponding to the bating part 6. , in a dowel for sorting catches in a trawl net, which is made up of the bating part 6 and a dowel part 8 attached to the rear end of the beret part 7, the rear end of the dowel part 8 is formed into a semi-cylindrical shape, and a part of suitable size is formed on this. The cap 11 is provided with a cap 11 which is integrally formed in the shape of a mesh bag with meshes and a semicircular sphere without any seams.

Therefore, the closed cap 11 at the rear end of the closed portion 8
When seining, water resistance is applied almost uniformly to the entire bag net, and each mesh is pulled evenly in all directions and opened, which improves shedding and reduces bycatch as much as possible. . In particular, by simply adjusting the mesh size of the cap 11, any kind of fish can be intentionally selected and caught, so a highly practical trawl net for catch selection can be provided.

[Brief explanation of the drawing]

Figure 1 is a side view of a Japanese flounder, Figure 2 is a side view of a sablefish, Figure 3 is a side view of a flathead flounder,
FIG. 4 is a plan view of a white crab, FIG. 5 is a developed view showing the structure of a conventional trawl net, FIG. 6 is a perspective view showing the entire trawl net according to the present invention, and FIG.
Figure 8 is a developed view of the capped cap according to the present invention.
The figure is a perspective view of the knotted cap in a sewn and assembled state, FIG. 9 is a perspective view of the same knotted cap in a used state, and FIGS. 10 and 11 are enlarged perspective views of main parts showing the conventional knotted end in a sewn state. It is. 1... Crow flounder, 2... Gindara, 3,
3'... Sleeve part, 4,4'... Armpit part, 5... Scare part, 6... Batting part, 7... Beret part, 8...
...Kotted Club, 11...Kotted Cap.

Claims (1)

[Scope of utility model registration request] A trawl net consisting of left and right sleeve parts and the left and right armpit parts that follow them, a skier part and a batting part that follows it, a beret part that corresponds to the batting part, and a batted part that is attached to the rear end of the batting part and the beret part. The rear end of the tipped part is formed into a semi-cylindrical shape, and a tipped cap, which is integrally formed in the shape of a bag mesh with appropriately sized meshes and has no seams, is attached to the tipped end. A trowel for sorting catches in a trawl net, characterized in that it is provided at the rear end of the trawl net.