University of British Columbia, Institute for the Oceans and Fisheries, Vancouver, British Columbia, Canada.
Centre for Fisheries Ecosystems Research, Fisheries and Marine Institute of Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada.
PLoS One. 2018 Jul 6;13(7):e0196307. doi: 10.1371/journal.pone.0196307. eCollection 2018.
This paper analyzes the trophic role of Pacific herring, the potential consequences of its depletion, and the impacts of alternative herring fishing strategies on a Northeast Pacific food web in relation to precautionary, ecosystem-based management. We used an Ecopath with Ecosim ecosystem model parameterized for northern British Columbia (Canada), employing Ecosim to simulate ecosystem effects of herring stock collapse. The ecological impacts of various herring fishing strategies were investigated with a Management Strategy Evaluation algorithm within Ecosim, accounting for variability in climatic drivers and stock assessment errors. Ecosim results suggest that herring stock collapse would have cascading impacts on much of the pelagic food web. Management Strategy Evaluation results indicate that herring and their predators suffer moderate impacts from the existing British Columbia harvest control rule, although more precautionary management strategies could substantially reduce these impacts. The non-capture spawn-on-kelp fishery, traditionally practiced by many British Columbia and Alaska indigenous peoples, apparently has extremely limited ecological impacts. Our simulations also suggest that adopting a maximum sustainable yield management strategy in Northeast Pacific herring fisheries could generate strong, cascading food web effects. Furthermore, climate shifts, especially when combined with herring stock assessment errors, could strongly reduce the biomasses and resilience of herring and its predators. By clarifying the trophic role of Pacific herring, this study aims to facilitate precautionary fisheries management via evaluation of alternative fishing strategies, and thereby to inform policy tradeoffs among multiple ecological and socioeconomic factors.
本文分析了太平洋鲱鱼的营养角色、其枯竭的潜在后果，以及替代鲱鱼捕捞策略对东北太平洋食物网的影响，以实现预防性的、基于生态系统的管理。我们使用了一个针对加拿大不列颠哥伦比亚省北部的生态路径与生态模拟(Ecopath with Ecosim)生态系统模型，利用 Ecosim 模拟鲱鱼种群崩溃对生态系统的影响。通过在 Ecosim 中的管理策略评估(Management Strategy Evaluation)算法，研究了各种鲱鱼捕捞策略的生态影响，同时考虑了气候驱动因素和种群评估误差的可变性。Ecosim 的结果表明，鲱鱼种群的崩溃将对大部分浮游生物食物网产生级联影响。管理策略评估的结果表明，尽管更具预防性的管理策略可以大大减少这些影响，但不列颠哥伦比亚省现有的收获控制规则对鲱鱼及其捕食者仍会造成中等程度的影响。传统上由不列颠哥伦比亚省和阿拉斯加原住民实施的棕背鸬鹚产卵于巨藻渔业，显然对生态系统的影响极其有限。我们的模拟还表明，在东北太平洋鲱鱼渔业中采用最大可持续产量管理策略可能会产生强烈的、级联的食物网效应。此外，气候变化，特别是与鲱鱼种群评估误差相结合时，可能会强烈降低鲱鱼及其捕食者的生物量和恢复力。通过阐明太平洋鲱鱼的营养角色，本研究旨在通过评估替代捕捞策略来促进预防性渔业管理，并在多个生态和社会经济因素之间进行政策权衡。
