疏目拖网改革试验

Experiment of Large-mesh Otter Board Trawl Modification

将单拖网具的网目从原来的140．0mm放大到400．0mm、2000．0mm和8000．0mm之后，相应的网口周长也从原来的72．8m扩大到88．0m、148．0m和300．0m。在渔船主机功率不变的情况下，相应的拖速从3．0节提高到4．0、4．5和5．0节。网口高度也提高了2-5m。生产试验捕捞中上层等栖息水层较高的鱼类，渔获产量明显地提高。

The modification of otter board trawl, of which the former mesh size was enlarged from 140. 0mm to 400. 0mm, 2000. 0mm and 8000. 0mm respectively, was reported in this paper. As a result of the modification, the circumference of net mouth increased from 72. 8m to 88.0m, 148. 0 m and 300. 0m accordingly, the trawling speed climbed from 3 knots to 4 - 5 knots with the same main engine power of fishing boat, and the vertical opening of net mouth gained 2 - 5 meters. The fishing efficiency improves very much.