Sparse mesh metalimnion otter-trawl

Abstract

The invention relates to a sparse mesh metalimnion otter-trawl with high fishing efficiency. The otter-trawl is characterized in that a single foot line of a net sleeve is connected with a net stem in a contact mode, and has the advantages that: firstly, a single foot line structure is adopted so as to make curves at the sleeve side smooth and evasive, have good buffering effect, save netting twine, reduce the friction on the sleeve side and water resistance and be repaired easily; secondly, the netting twines at the sleeve side are extremely thick with the thickness more than twice of a thick line of a master ruler basic netting twine so as to resist the wear, prolong the service life, and the like; thirdly, net mesh is super large, the maximum can be 30m so that the filtering speed of the net mesh is quick, so the otter-trawl can protect the parr resource; besides, the resistance is small, the net towing speed of a netting gear is high, and the sweeping area of the netting gear is multiple in unit time; and fourthly, the otter-trawl can perform metalimnion operation which expands the fishing space of intermediate water and superjacent water, breaks through the mode that the conventional otter-trawl can only operate in the bottom layer, effectively reduces the pressure that bottom marine resources are overfished, and accords with the national marine resources policy.

Description

Technical field: [0001] The invention relates to a fishing tool, in particular to a single trawling net with wide mesh and variable water layer, which has high fishing efficiency and long service life. Background technique: [0002] As we all know, trawling is the most widely used fishing tool in ocean fishing, and traditional trawls are divided into double trawl gear and single trawl gear. The double trawl gear is towed by two tugboats to drag the two trawl nets separately, so that the double trawl mouths are opened for fishing. The disadvantage is that two tugboats must operate at the same time, the energy utilization rate is low, and most countries in the world prohibit double trawling. Operations, etc.; single trawl gear is towed by a single boat, and the net mouth is opened by the horizontal expansion of the water diversion board. Compared with double trawl nets, single trawl gear has the advantages of protecting fishery resources, convenient operation, energy saving, a...

AI Technical Summary

Problems solved by technology

The double trawl gear is towed by two tugboats to drag the two trawl nets separately, so that the double trawl mouths are opened for fishing. The disadvantage is that two tugboats must operate at the same time, the energy utilization rate is low, and most countries in the world prohibit double trawling. Operations, etc.; single trawl gear is towed by a single boat, and the net mouth is opened by the horizontal expansion of the water diversion board. Compared with double trawl nets, single trawl gear has the advantages of protecting fishery resources, convenient operation, energy saving, and international general access. However, the traditional single trawl has the following disadvantages: (1) the mesh is small, the water filtration is slow, and the maximum mesh is not more than 50cm, which is not conducive to the release of juvenile fish; due to the small mesh, the dragging speed of the net is slow, and the sea sweeping area is small. The output is low, the maximum dragging speed is only 2.5 knots / hour, and it is impossible to catch large fish; (2) The process structure is complicated, and the net body and the net sleeves are sewn from multiple pieces of mesh, that is to say, the net body is made of multiple pieces of mesh The net is longitudinally connected into a conical shape along the net body. In order to achieve a smooth structure, the net body is at most made of eight or ten nets by cutting and sewing. The net body is not smooth, the water resistance is large, and the expansion is insufficient. The work efficiency is low and the process is very difficult, which affects the popularization and use of single trawl nets; (3) the use object is limited: it is only suitable for bottom-level waters, and the upper-middle waters can only be blank; it is only suitable for domestic operations and short-term operations in individual countries in the world , which is not conducive to the international development of pelagic fisheries; (4) Because the connection between the net stem and the net sleeve edge is a winding connection, the network cable is wasted. short

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