One-boat beam haul-bag single-sac bottom trawl for investigating and sampling marine demersal creatures

Abstract

The invention relates to towing net, in particular to a one-boat beam haul-bag single-sac bottom trawl for investigating and sampling marine demersal creatures, and aims to provide a one-boat beam haul-bag single-sac bottom trawl for investigating and sampling marine demersal creatures. The trawl is stable in opening width and easy for pouring captures. The one-boat beam haul-bag single-sac bottom trawl for investigating and sampling marine demersal creatures comprises a warp, an outer cross rope, inner cross ropes, a beam, sinkers, a head, a body and a sack. The warp is connected with the inner cross ropes through the outer cross rope. The inner cross ropes are fixedly connected to eye rings on left and right sides of the beam. The top of an opening of the head is fixedly connected to the beam. The sinkers are fixedly connected to the bottom of the opening of the head. The section of the body gradually shrinks from front to rear. The opening large end of the body is connected with the head. The opening small end of the body is connected with the sack. A sample exit is arranged at the rear end of the sack, and a sack tying cord is disposed at the sample exit.

Description

technical field [0001] The invention belongs to the field of marine biological investigation, in particular to a sampling trawl net for marine bottom biological investigation. Background technique [0002] The survey of marine bottom organisms is an important part of the comprehensive survey of the basic marine science. Every year, routine surveys are carried out in various sea areas in my country. In the scientific investigations of the Antarctic, Arctic and oceans, the survey of marine bottom organisms is also an indispensable content. At present, the survey of bottom organisms carried out in the polar regions and oceans mostly uses a single-boat bottom type winged single-vessel trawling net (such as figure 1 ), operated by oceanographic research vessels with stern slides or large stern slide trawlers. The survey of bottom organisms in my country's coastal waters mostly uses double-boat bottom-bottom winged single-vessel trawls (such as figure 2 ) or single-vessel botto...

AI Technical Summary

Problems solved by technology

The single-bottom winged single-vessel trawl net has the advantages of actively hunting swimming organisms and benthic organisms, active flexibility, wide operating range, high fishing efficiency, and easy sampling. It is expanded by the horizontal component force generated by the impact of the water flow, and the water flow is mainly affected by the dragging speed, so the expansion width of the mesh port is not easy to stabilize

The double-bottom winged single-vessel trawl also has the advantages of actively hunting swimming organisms and benthic organisms, being more active and flexible, having a wider operating range, higher fishing efficiency, and easier sampling. It is determined by the distance when towing, so the width of the network port is also unstable. At the same time, the double-vessel towing operation increases the difficulty of communicating with each other and coordinating actions.

The bottom-floor truss-type trawling net of a single ship is a traditional net gear for offshore and shallow sea operations. Its advantage is that the width of the net mouth is fixed and expanded by the truss tied to the upper net of the net mouth, and can be kept unchanged during the operation. There is a row of hanging bags (commonly known as net curtains) folded into the mesh bag above the net mouth of the net. When swimming animals with strong bouncing power (such as prawns) and fast regression speed (such as squid and squid) enter the net After entering the net, when trying to escape backward and upward by bouncing or retreating quickly, it falls into the hanging bag, which improves the accuracy of sampling, but the net does not have a mesh bag with a rear opening, so it is very inconvenient to retrieve the catch

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