JP3513627B2 - Troll type fishery resource sample collection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trawl type fishery resource sample collection device which can be formed into a relatively large net opening and which is easy to handle. is there. [0002] Knowing the amount of plankton and juveniles that live in the sea is important in estimating the amount of fishery resources in the area.
This is a very important matter, and for this purpose, a certain amount of the fry is collected, that is, sampling is performed. [0003] A fishery resource sample collecting device is used for this, and the collecting device is generally formed in a trawl net shape, but the shape of the mouth can be various. . And sampling of this collection device while towing by boat is similar to general commercial trawl nets, but the net mouth basically does not change during the towing and must always be deployed. No. [0004] For this purpose, a method which has been generally adopted in the past is to dispose a metal frame such as an iron or the like in the form of an annular or square shape in accordance with the shape of the mesh at the mesh opening. Met. [0005] When a metal frame is used as described above, the net opening of the collection device is always developed in a constant shape, which is extremely good in that sense. It is pointed out. That is, in the case where the frame is made of metal as described above, if the frame is made large, the weight becomes excessively large, which hinders the handling and causes the trouble during towing. The generated resistance becomes large, and although it is made of metal, the frame is deformed. Therefore, in consideration of the strength, the size must be reduced inevitably. The limit of the conventional frame body is a maximum of about 2 m in diameter at the maximum, so that the collecting device also needs to form the net opening of about 2 m. [0007] However, in the case of using such a collecting device having a small net mouth, it is difficult to collect a young fish having a relatively large swimming power due to the small net mouth.
In such a case, a so-called commercial trawl net was used instead, but according to this, even if there is no particular problem when the towing speed is constant, if the towing speed changes, the net opening is changed. Since this influences the shape and changes the shape of the mouth opening and the area thereof, it is completely unsuitable as this kind of collecting tool for the purpose of quantitative collection. On the other hand, in the case of a collecting tool provided with a metal frame as described above, the collecting tool must be lifted onto a ship after collecting, which is inconvenient to handle. This is the same when casting a net from a ship, but in short, it could not be deformed at all artificially. [0009] In order to solve the above-mentioned problems, a trolling type fishery resource sample collection device according to the present invention has one or more flexible strip-shaped sheets formed of synthetic fibers. A wire rope is arranged along the longitudinal direction of the wire rope to form a cylindrical shape, and a net collecting body formed into a trawl net shape with a large-diameter net formed in the towing direction front of the net collecting device. It is arranged at the mouth of the tool. [0010] That is, in the initial stage of the casting, the net is expanded by a small otter board separately provided, and thereafter, the annular shape is maintained by itself by the action of the core wire rope, and accidental deformation is prevented. In addition, the towed net is provided with an appropriate resistance to flowing water with the towing, so that the net mouth can always be normally deployed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, a trawling type fishery resource sample collecting device according to the present invention will be described. The netting body 1 is formed by arranging a desired number of wire ropes 3 in a longitudinal direction on a flexible band-shaped sheet 2 woven with synthetic fibers, and is formed in a ring shape as a whole. Further, the net-like expansion body 1 formed in an annular shape, that is, in a tubular shape, is formed so that the diameter of the front side in the towing direction becomes larger. The reason why the annular shape is formed here is to match the shape of the mesh opening 5 of the collecting tool 4 described later. Further, as for the annular state, for example, it is possible to form an annular shape as an integral body. When a plurality of fragments are connected in this manner, the collecting tools 4 having different sizes are used.
Has the advantage that it can correspond to the shape of the mesh opening 5. The net-shaped expanding body 1 is disposed in the net opening 5 of the net collecting tool 4 formed in a trawl net shape. When arranging the netting body 1 at the net opening 5 in this manner, as shown in FIG. 2, for example, it is arranged so that both end edges of the netting body 1 are entangled with a string or the like from the outside of the collection tool 4. In this case, or as shown in FIG. 4, the end of the web-enlarged body 1 on the side forward from the inside of the collecting tool 4 in the towing direction is entangled with a string or the like, and the other end is loosely connected to the collecting tool 4 with the string 6. In some cases, as shown in FIG. 6, the end of the web-enlarged body 1 on the side that is rearward in the towing direction from the outside of the collection tool 4 is entangled with a string or the like, and the other end is loosely connected with the string 6. is there. Thus, the collecting device 4 may be towed in the same manner as in the prior art. However, the expanding net 1 used here has a possibility of being deformed as described above. In the early stage of casting, the opening 5 may not be deployed immediately. Therefore, in the present invention, a relatively small otter board (not shown) is provided on the towing line 7. The otter board acts together with the floats and sinks disposed on the net opening 5 to immediately deploy the net opening 5 after casting, and to exert the sinking force of the entire collection tool 4 by weighing the otter board. become. Therefore, it is sufficient for the otter board used here to perform functions only for that purpose. During towing, the mesh mouth 5 continues to be developed due to the shape of the netting body 1, and the moderately flowing water resistance to the netting body 1 is applied, so that the netting body 1 is evenly expanded, The opening of the mouth 5 becomes even. Then, although the deployment force changes in accordance with the towing speed, the balance of the force on the entire inner surface of the expanding net 1 is the same. As described above, according to the trawling fishery resource sample collecting device of the present invention, one or more wire ropes are attached to the flexible belt-like sheet made of synthetic fiber in the longitudinal direction. Along with the configuration, a tubular body is formed along with the net collecting device, and a net expanding body formed with a large diameter at the front in the towing direction of the net collecting device is arranged at the mouth of the net collecting device formed in a trawl net shape. Since it is installed, in the early stage of casting, it is expanded by a small otter board separately arranged, and after that, while maintaining the annular shape by itself by the action of the core wire rope, preventing accidental deformation, In addition, it provides a moderate flow resistance to the expanding net as it is towed, so that the net opening can always be deployed normally, and the net opening can be enlarged and the handling becomes easy. It has an effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing one embodiment of a trawling fishery resource sample collection device according to the present invention. FIG. 2 is an explanatory diagram showing an arrangement state of a network expansion body in FIG. 1; FIG. 3 is a perspective view showing another example of the trawling fishery resource sample collection device according to the present invention. FIG. 4 is an explanatory diagram showing an arrangement state of a network expansion body in FIG. 3; FIG. 5 is a perspective view showing another example of the trawling fishery resource sample collection device according to the present invention. FIG. 6 is an explanatory diagram showing an arrangement state of a net expanding body in FIG. 5; FIG. 7 is a perspective view showing a part of the net expander. [Explanation of Signs] 1 Enlargement body 2 Sheet 3 Wire rope 4 Collecting tool 5 Net mouth 6 String 7 Towing line

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-53-38573 (JP, A) JP-A-53-162084 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A01K 73/00 A01K 75/00

Claims (1)

(57) [Claims 1] One or a plurality of wire ropes arranged on a flexible band-like sheet formed of synthetic fiber along the longitudinal direction thereof are formed in a cylindrical shape. With
A net-shaped body formed with a large diameter in the towing direction of the net collection device,
A troll-type fishery resource sample collection device, which is disposed at the mouth of a net collection device formed in a trawl net shape.