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首页> 外文OA文献 >A study on the escape rate of Northeast Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) under the fishing line with two different ground ropes in the Barents Sea bottom trawl fisheryand the influence of some biotic and abiotic factors on the efficiency during bottom trawling
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A study on the escape rate of Northeast Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) under the fishing line with two different ground ropes in the Barents Sea bottom trawl fisheryand the influence of some biotic and abiotic factors on the efficiency during bottom trawling

机译：巴伦支海底拖网渔业中两种不同地绳在钓鱼线下东北大西洋鳕鱼（Gadus morhua）和黑线鳕（melanogrammus aeglefinus）逃逸率的研究 以及一些生物和非生物因素对底拖网捕捞效率的影响

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摘要

The aim of this study was to investigate the escapement under the fishing line for cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) with the conventional rock-hopper gear and a new type of gear termed semicircular spreading gear (SCSG). The trials were conducted during November 2014 and February 2015 in the Barents Sea under varying environmental conditions. In order to catch the escapees a retainer bag was attached to the fishing line of the trawl. Multi model averaging was applied for calculating the efficiency, i.e. escapement rate for all length groups. A highly significant difference in the rate of escapement between the two types of ground-gears was found. Summarized for all length groups above 65 cm, 14% of the cod escaped under the fishing line of the rock-hopper gear, and 5% under the SCSG during the trials in November 2014. This resulted in an efficiency improvement of 11%, and escapement reduction of 67%. In February 2015 the escapement was 5% for the rock-hopper, and 2% for the SCSG, resulting in an efficiency improvement of 3%, and an escapement reduction of 57%. The overall improvement of efficiency for cod is thus 8%, and a reduction in escapement of 63%. The escapement of haddock for all lengths above 62 cm was estimated to 7% for the rock-hopper gear, and 1% for the SCSG, implying an efficiency improvement of 6%, and an escapement reduction of 85%. Based on the present data no correlation was found between the rate of escapement and fish density, ambient light intensity, nor artificial light. However, a positive correlation was obtained between temperature and the escapement rate for some length groups.Over the recent years the tendency in the bottom trawl fisheries has been increasing the trawl dimension in order to increase efficiency, with subsequent increase in fuel consumption and emission, as well as possibly increased negative bottom impact. The demonstrated improvement of the SCSG compared to the conventional rock-hopper gear entails multiple advantages such as increased efficiency due to reduced escapement, reduced fuel consumption and emission, and reduced negative bottom impact. By introducing a more efficient ground-gear this study provides an improvement from the current situation that is believed to be of importance both from fisheries and environmental point of view, as well as for the accuracy of the trawl surveys for stock assessment purpose.Keywords: Escapement, efficiency, rock-hopper, semicircular spreading gear, fish behavior
机译：这项研究的目的是研究鳕鱼（Gadus morhua）和黑线鳕（Melanogrammus aeglefinus）在钓线下的擒纵机构，该擒纵机构采用传统的漏斗式渔具和一种称为半圆展开式渔具（SCSG）的新型渔具。该试验于2014年11月至2015年2月在巴伦支海的不同环境条件下进行。为了抓住逃生者，在拖网的钓线上安装了一个固定袋。应用多模型平均来计算效率，即所有长度组的擒纵速率。发现两种类型的齿轮之间的擒纵速率有非常显着的差异。在2014年11月进行的试验中，对于65厘米以上的所有长度的鱼群进行总结，鳕鱼在石漏斗渔具的钓线下逸出了14％，在SCSG钓具下逸出了5％。效率提高了11％，并且擒纵机构减少67％。 2015年2月，料斗的擒纵力为5％，SCSG的擒纵力为2％，效率提高了3％，擒纵力降低了57％。因此，鳕鱼的总效率提高了8％，逸出量降低了63％。对于料斗齿轮，所有长度超过62 cm的黑线鳕的逃逸率估计为7％，对于SCSG，则为1％，这意味着效率提高了6％，逃逸率降低了85％。根据目前的数据，在逃逸率与鱼类密度，环境光强度或人造光之间未发现相关性。然而，对于某些长度的群体，温度与逃逸率之间存在正相关关系。近年来，底层拖网渔业的趋势是增加拖网尺寸以提高效率，随后增加燃料消耗和排放，以及可能增加的负面底部影响。与传统的碎石斗齿轮相比，SCSG的改进得到了诸多好处，例如由于减少了擒纵机构而提高了效率，减少了油耗和排放，并减少了不利的底撞。通过引入更有效的地面设备，这项研究提供了从当前状况出发的改进，从渔业和环境的角度来看，这对渔业和环境的观点都是重要的，对于拖网调查的准确性也很重要。逃逸，效率，碎石斗，半圆展开器，鱼类行为

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    Brinkhof Jesse;

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  • 年度 2015
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