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首页> 外文期刊>ICES Journal of Marine Science >Incorporating density dependence in pup production in a stock assessment of NE Atlantic spurdog Squalus acanthias
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Incorporating density dependence in pup production in a stock assessment of NE Atlantic spurdog Squalus acanthias

机译：将密度依赖性纳入幼犬生产中，评估东北大西洋刺刺鱼Squalus acanthias的种群

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摘要

An age- and sex-structured stock assessment model for Northeast Atlantic spurdog Squalus acanthias is presented that includes length-based processes, such as maturation, pup production, growth, and gear selectivity, with a length-at-age relationship to convert length to age. It relates pup production functionally to numbers of pregnant females, allowing for density-dependent effects. The model was fitted to a combined Scottish groundfish survey biomass index, to proportion-by-length category data from both trawl surveys and commercial catch sampling from target and non-target fisheries, and to fecundity data. The model was run from 1905 to better reflect virgin conditions and to allow early fecundity data to be fitted in order to estimate the extent of density dependence in pup production. The model estimated 2010 population levels to be about 23% relative to 1955 and 19% relative to 1905. Results confirm that the stock is depleted, but not to the extent estimated in a previous assessment. Current estimates of depletion would support an IUCN listing of "Endangered", but not "Critically Endangered". Model projections showed that a TAC of 1422 t (the last non-zero TAC) would allow future population growth.
机译：提出了一种东北大西洋红刺刺鲨Scanus acanthias的年龄和性别结构的种群评估模型，该模型包括基于长度的过程，例如成熟，幼仔生产，生长和渔具选择性，并具有年龄与年龄的关系以将长度转换为年龄。它在功能上与幼仔的数量有关，从而产生密度依赖性效应。该模型适用于苏格兰海底鱼类调查生物量综合指数，拖网调查和目标和非目标渔业的商业捕捞抽样的按长度比例分类的数据以及繁殖力数据。该模型从1905年开始运行，以更好地反映原始条件并允许拟合早期繁殖力数据，以估计幼仔生产中密度依赖性的程度。该模型估计2010年的人口水平相对于1955年约为23％，而相对于1905年约为19％。结果证实了种群的消耗，但未达到先前评估的估计水平。目前的消耗估计数将支持自然保护联盟将其列为“濒危”，但不列为“严重濒危”。模型预测显示，TAC为1422 t（最后一个非零TAC）将允许将来的人口增长。

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