| 摘要 |
In one aspect, the sweepline system of the invention include a sweepline chain divided into a series of uniform subunits of common length attached along its U-shaped length to the hanging chains of the bottom trawl wherein such sweepline system is provided with its own separate auxiliary floatation system. In another aspect, a series of transverse drag chains are attached relative to the sweepline chain or the like, at a series of equally spaced junctions and downwardly sweep from such junctions in a downwardly depending direction, such junctions being located below the trawl net but above the bottom of the ocean, sea or the like wherein each drag chain comprises a series of chain links of overall length L defining a series of hinges therealong at the intersection of the individual links. In yet another aspect, the auxiliary floatation system of the invention is constructed so as to maintain attaching ends of the transverse drag chains (coincident with the series of junctions) at a rest elevation E above the ocean or sea bottom wherein L>E whereby a free end portion of each drag chain rests on the ocean bottom but at any conventional towing speed, such free end portion changes orientation relative to the ocean bottom due to the resistance of the water to be angled away from the direction of net towing but wherein such free end portion still has an included segment that remains in contact with the ocean bottom to form both a physical and a visible deterrent to fish to thereby prevent their escape under the trawl net.
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