Further evidence that Antarctic toothfish are important to Weddell seals
Further evidence that Antarctic toothfish are important to Weddell seals
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DOI：
10.1017/s0954102020000437
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发表时间：
2021-02-01
影响因子：
1.6
通讯作者：
Abrams, Peter A.
中科院分区：
文献类型：
--
作者：
Ainley, David G.;Cziko, Paul A.;Abrams, Peter A.
南极洋枪鱼Dissostichus mawsoni和威德尔海豹Leptonychotes weddellii是南极大陆架沃茨重要的中食动物。它们互相竞争猎物，但海豹也捕食洋枪鱼。这种行会内的捕食意味着患病率和各自的人口统计率可能是负相关的，但缺乏量化。在回顾了它们的自然历史之后，我们提出了一种解决这一缺陷的方法，即结合罗斯海麦克默多湾海豹丰度的年度指数，分析每单位努力量的科学捕捞量（CPUE; 1975-2011年加上零星努力到2018年）。我们将科学CPUE的年度变化与43年（1975-2018年）的海豹数量相关联，补充了同一地区早期的一项研究，该研究表明CPUE与丰富海豹的空间接近度呈负相关。所观察到的关系（更多的海豹CPUE较低，同时控制每年的趋势）表明的重要性，洋枪鱼作为一个饮食项目威德尔海豹，并强调了可能的重要性，内部和种间竞争，以及intraguild捕食海豹洋枪鱼动态。最后，可能有必要以有针对性的生态系统监测来补充渔业管理，以防止渔业对依附物种产生不利影响。
Antarctic toothfish Dissostichus mawsoni and Weddell seals Leptonychotes weddellii are important mesopredators in the waters of the Antarctic continental shelf. They compete with each other for prey, yet the seals also prey upon toothfish. Such intraguild predation means that prevalence and respective demographic rates may be negatively correlated, but quantification is lacking. Following a review of their natural histories, we initiate an approach to address this deficiency by analysing scientific fishing catch per unit effort (CPUE; 1975-2011 plus sporadic effort to 2018) in conjunction with an annual index of seal abundance in McMurdo Sound, Ross Sea. We correlated annual variation in scientific CPUE to seal numbers over a 43 year period (1975-2018), complementing an earlier study in the same locality showing CPUE to be negatively correlated with spatial proximity to abundant seals. The observed relationship (more seals with lower CPUE, while controlling for annual trends in each) indicates the importance of toothfish as a dietary item to Weddell seals and highlights the probable importance of intra- and inter-specific competition as well as intraguild predation in seal-toothfish dynamics. Ultimately, it may be necessary to supplement fishery management with targeted ecosystem monitoring to prevent the fishery from having adverse effects on dependent species.