Abstract Size-selective grids in the Barents Sea trawl fisheries have demonstrated large variation in sorting capacity. When combined with dynamic catch-control systems for regulating catch quantity, surplus fish are washed out at the surface. The objective of this study was to develop a codend concept that releases more undersized fish than the most commonly used size–selectivity device in the Barents Sea trawl fishery (flexigrid combined with a two-panel 130 mm codend). Fishing with twin trawls, a four-panel 153 mm codend concept with short lastridge ropes to force open meshes was compared with a flexigrid combined with a 130 mm mesh codend, in terms of size selectivity for cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and saithe (Pollachius virens). Compared to the grid–codend setup, the four–panel codend with short lastridge ropes retained about half of 54.5–59.4 cm gadoids, with catches of undersized cod, haddock and saithe reduced by 90 (ci = 85–94), 92 (ci = 88–96) and 86 % (ci = 79–92) respectively. The study demonstrated that the four-panel codend concept releases more undersized fish than the flexigrid-codend combination.

中文翻译：

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在巴伦支海 gadoid 拖网渔业中，与带有常规代码的 flexigrid 相比，带有短尾绳的四面板代码的相对尺寸选择性

摘要 巴伦支海拖网渔业中的尺寸选择网格在分拣能力方面表现出很大差异。当与用于调节捕捞量的动态捕捞控制系统相结合时，多余的鱼会在水面被冲走。本研究的目的是开发一种编码器概念，它比巴伦支海拖网渔业中最常用的尺寸选择性装置（flexigrid 结合两块 130 毫米编码器）释放更多的小鱼。使用双拖网捕鱼，在鳕鱼 (Gadus morhua)、黑线鳕 (Melanogrammus aeglefinus) 的尺寸选择性方面，将四块 153 毫米带短尾绳以强制打开网眼的编码器概念与 flexigrid 结合 130 毫米网孔编码器进行了比较) 和 saithe (Pollachius virens)。与 grid-codend 设置相比，带有短尾脊绳的四板条码保留了大约一半的 54.5-59.4 厘米的鲱鱼，小鳕鱼、黑线鳕和赛特的捕获量减少了 90 (ci = 85-94)、92 (ci = 88-96) 和 86% (ci = 79–92) 分别。研究表明，四块板码的概念比 flexigrid-codend 组合释放出更多的小鱼。