UiT, The Arctic University of Norway, Tromsø, Norway.
SINTEF Ocean, Trondheim, Norway.
PLoS One. 2021 Mar 26;16(3):e0249172. doi: 10.1371/journal.pone.0249172. eCollection 2021.
Several shrimp trawl fisheries use a Nordmöre sorting grid to avoid bycatch of fish. However, small fish can pass through the grid. Therefore, the retention of juvenile fish often remains an issue during shrimp trawling. We investigated the vertical distribution of deepwater shrimp (Pandalus borealis) and dominant bycatch species at the point where the Nordmöre grid section is installed. This was achieved using a separator frame which split the net vertically into three compartments of equal entry size. Our results showed that shrimp predominately follow the lower part of the trawl belly, whereas species such as redfish (Sebastes spp.), cod (Gadus morhua), polar cod (Boreogadus saida) and American plaice (Hippoglossoides platessoides) preferred the mid-section in the aft of the trawl. Haddock (Melanogrammus aeglefinus) primarily entered through the upper section of the trawl belly. Using these results, we predict that a vertical separation device installed forward of a 19 mm Nordmöre grid combined with a 35 mm codend would result in a significant reduction in bycatch with only minor loss of shrimp.
几种虾拖网渔业使用 Nordmöre 分拣格栅来避免兼捕鱼类。然而，小鱼可以通过格栅。因此，在虾拖网捕捞过程中，幼鱼的保留仍然是一个问题。我们调查了深水虾（北方长额虾）和主要兼捕物种在安装 Nordmöre 格栅部分的垂直分布情况。这是通过使用分离器框架实现的，该框架将网垂直地分为三个等入口大小的隔舱。我们的结果表明，虾主要跟随拖网腹部的下部，而鳕鱼（鳕鱼）、北极鳕鱼（Boreogadus saida）和美洲比目鱼（Hippoglossoides platessoides）等物种更喜欢拖网后部的中部。黑线鳕（Melanogrammus aeglefinus）主要通过拖网腹部的上部进入。根据这些结果，我们预测，在前部安装一个 19 毫米的 Nordmöre 格栅，再加上一个 35 毫米的网囊，将显著减少兼捕，而对虾的损失很小。
