Evaluating impacts of forage fish abundance on marine predators
Evaluating impacts of forage fish abundance on marine predators
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DOI：
10.1111/cobi.13709
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发表时间：
2021-06-01
影响因子：
6.3
通讯作者：
Hilborn, Ray
中科院分区：
文献类型：
--
作者：
Free, Christopher M.;Jensen, Olaf P.;Hilborn, Ray
饲料鱼——小型、低营养级的中上层鱼类，如鲱鱼、沙丁鱼和凤尾鱼——是海洋生态系统中的重要猎物物种，也支持大型商业渔业。在世界许多地区，饲料鱼渔业采用预防原则进行管理，目标是捕捞量低于最大可持续产量。然而，越来越多的人呼吁进一步限制饲料鱼的捕捞，以保护鱼类、海鸟和海洋哺乳动物的捕食者。这些额外预防性规定的有效性存在争议，这些规定假设猎物丰度的增加会提高捕食者的生产力。在这项研究中，我们使用与猎物相关的种群模型来测量饲料鱼丰度对 45 个海洋捕食者种群（代表来自世界 5 个地区的 32 种鱼类、海鸟和哺乳动物物种）种群增长率的影响。我们使用模拟数据来确认统计模型在不同影响强度和过程变异水平下准确检测猎物影响的能力。我们的结果表明，捕食者的生产力很少受到饲料鱼猎物丰度的影响。只有 6 个捕食者种群（占总数的 13%）受到猎物丰度增加的积极影响，并且该模型表现出强大的能力来检测猎物存在的影响。这些结果表明，将饲料鱼收获量进一步限制在远低于可持续产量的水平，很少会导致海洋捕食者种群数量明显增加。
Forage fish-small, low trophic level, pelagic fish such as herrings, sardines, and anchovies-are important prey species in marine ecosystems and also support large commercial fisheries. In many parts of the world, forage fish fisheries are managed using precautionary principles that target catch limits below the maximum sustainable yield. However, there are increasing calls to further limit forage fish catch to safeguard their fish, seabird, and marine mammal predators. The effectiveness of these extra-precautionary regulations, which assume that increasing prey abundance increases predator productivity, are under debate. In this study, we used prey-linked population models to measure the influence of forage fish abundance on the population growth rates of 45 marine predator populations representing 32 fish, seabird, and mammal species from 5 regions around the world. We used simulated data to confirm the ability of the statistical model to accurately detect prey influences under varying levels of influence strength and process variability. Our results indicate that predator productivity was rarely influenced by the abundance of their forage fish prey. Only 6 predator populations (13% of the total) were positively influenced by increasing prey abundance and the model exhibited high power to detect prey influences when they existed. These results suggest that additional limitation of forage fish harvest to levels well below sustainable yields would rarely result in detectable increases in marine predator populations.