Mesh Selectivity of Net Pot for White-spotted Conger Eel Estimated from a Cover-net Fishing Experiment.
Mesh Selectivity of Net Pot for White-spotted Conger Eel Estimated from a Cover-net Fishing Experiment.
复制标题
根据盖网捕捞实验估算的白斑海鳗网盆网眼选择性。
DOI：
10.2331/suisan.64.815
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发表时间：
1998
影响因子：
0.4
通讯作者：
K. Matuda
中科院分区：
文献类型：
--
作者：
K. Uchida;T. Tokai;Huang Fuxiang;K. Matuda
本文研究了白斑海鳗网箱的网目选择性。1995年10月和1996年10月进行了一次覆盖网捕捞试验，使用5个网孔; 11.6，13.6，15.5，18.1和21.0 mm，覆盖网的网孔为10.8 mm。不同网目尺寸网笼的网目选择性曲线在R（=G/P）、围长比G和网目周长P方面略有不同，但在小网囊中4种网目尺寸的网目选择性用一条单一的R曲线来描述。在网盆中，网以一定张力附接到盆的框架。网目形状的变形可能小于拖网。此外，由于试验中各网目尺寸网片的双径相同，网目尺寸越小，双径与网目长度的比值越大。这意味着海鳗在通过较小的网格时，要扭曲网格形状有点困难。网笼对R、R75-R25的选择范围大于小拖网网囊。海鳗很可能在拖上来的时候从锅里逃出来，因为只要鱼饵还在，它们就试图呆在锅里。在拖曳拖网中，网囊海鳗有更多的机会通过网逃脱，这是拖网网囊具有窄选择性范围的另一个可能原因。
This paper presents the mesh selectivity of a net pot for white-spotted conger eel Conger myriaster. A cover-net fishing experiment was carried out in October 1995 and 1996, using five mesh openings; 11.6, 13.6, 15.5, 18.1, and 21.0mm with a cover-net of 10.8mm mesh opening. Each mesh-size net pot had a slightly different mesh selectivity curve in terms of R(=G/P), girth ratio G to mesh perimeter P, although mesh selectivity of four mesh sizes in a small trawl codend was described by a single curve in terms of R. In the net pot, the net was attached to the frame of the pot with some tension. The distortion of mesh shape was probably less than that of the trawl net. Moreover, because the twin diameter of each mesh size net was the same in the experiment, for smaller mesh size the ratio of twin diameter to mesh length was relatively larger. This means that it was a little harder for conger eels to distort the mesh shape while passing through the smaller mesh. Selectivity ranges in terms of R, R75-R25 of net pot were larger than those of the small trawl codend. Conger eels are likely to escape from the pot just during hauling up, because they try to stay inside as long as bait remains. In a towed-trawl cod-end conger eels have more chance of escaping through the mesh, which is another possible reason why the trawl codend has a narrow selectivity range.