Conical pots are commonly used fishing gear for capturing snow crab (). In these fisheries, optimal snow crab size selection is important for reducing unintended mortality of undersized individuals aiming at conserving fisheries resources and reducing sorting time onboard fishing vessels. Size selection in snow crab pot fisheries commonly takes place through pot netting meshes during deployment. The diamond mesh netting has varying opening angles affecting retention of snow crab of different sizes, and often large proportions of catches consist of undersized crab challenging natural resource conservation. Some commercial snow crab fisheries use rigid escape gaps in addition to mesh selection to improve size selectivity. In this study, we predict the size selection potential of escape gaps with different shape and size and investigated whether such additional size selection mechanism can have a potential to improve selectivity compared to mesh selection. Results showed that circular escape gaps have potential to provide sharper size selection compared to netting meshes and thus could be used to limit the capture of undersized snow crab which is relevant for management and conservation of snow crab resources. However, a similar positive effect cannot be obtained to the same extent with elliptical and rectangular escape gaps.

中文翻译：

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雪蟹（Chionoecetes opilio）盆栽捕捞的选择性：逃逸间隙形状和大小对渔业资源保护的影响

锥形盆是捕获雪蟹常用的渔具（）。在这些渔业中，最佳雪蟹尺寸选择对于减少体型过小的个体的意外死亡非常重要，从而保护渔业资源并减少渔船上的分类时间。雪蟹网箱渔业中的尺寸选择通常是在部署过程中通过网网进行的。菱形网具有不同的张开角度，影响不同尺寸的雪蟹的保留，并且通常大部分捕获量是尺寸过小的蟹，这对自然资源保护提出了挑战。一些商业雪蟹渔业除了选择网目外还使用刚性逃逸间隙来提高尺寸选择性。在本研究中，我们预测了不同形状和尺寸的逃逸间隙的尺寸选择潜力，并研究了与网格选择相比，这种额外的尺寸选择机制是否有可能提高选择性。结果表明，与网状网相比，圆形逃逸间隙有可能提供更精确的尺寸选择，因此可用于限制尺寸过小的雪蟹的捕获，这与雪蟹资源的管理和保护相关。然而，使用椭圆形和矩形逃逸间隙不能获得相同程度的类似积极效果。