Adaptive spatiotemporal management to reduce shark bycatch in tuna fisheries

IF 5.2 1区 环境科学与生态学 Q1 BIODIVERSITY CONSERVATION
Guillermo Ortuño Crespo, Shane Griffiths, Hilario Murua, Henrik Österblom, Jon Lopez
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引用次数: 0

Abstract

Purse-seine tropical tuna fishing in the eastern tropical Pacific Ocean (EPO) results in the bycatch of several sensitive species groups, including elasmobranchs. Effective ecosystem management balances conservation and resource use and requires considering trade-offs and synergies. Seasonal and adaptive spatial measures can reduce fisheries impacts on nontarget species while maintaining or increasing target catches. Identifying persistently high-risk areas in the open ocean, where dynamic environmental conditions drive changes in species’ distributions, is essential for exploring the impact of fisheries closures. We used fisheries observer data collected from 1995 to 2021 to explore the spatiotemporal persistence of areas of high bycatch risk for 2 species of oceanic sharks, silky shark (Carcharhinus falciformis) and oceanic whitetip shark (Carcharhinus longimanus), and of low tuna catch rates. We analyzed data collected by fisheries scientific observers onboard approximately 200 large purse-seine vessels operating in the EPO under 10 different flags. Fishing effort, catch, and bycatch data were aggregated spatially and temporally at 1° × 1° cells and monthly, respectively. When areas of high fishing inefficiency were closed the entire study period and effort was reallocated proportionally to reflect historical effort patterns, yearly tuna catch appeared to increase by 1–11%, whereas bycatch of silky and oceanic whitetip sharks decreased by 10–19% and 9%, respectively. Prior to fishing effort redistribution, bycatch reductions accrued to 21–41% and 14% for silky and oceanic whitetip sharks, respectively. Our results are consistent with previous findings and demonstrate the high potential for reducing elasmobranch bycatch in the EPO without compromising catch rates of target tuna species. They also highlight the need to consider new dynamic and adaptive management measures to more efficiently fulfill conservation and sustainability objectives for exploited resources in the EPO.

Abstract Image

适应性时空管理,减少金枪鱼渔业中的鲨鱼误捕。
在东热带太平洋(EPO)用围网捕捞热带金枪鱼会误捕多个敏感物种群,包括鞘鳃类。有效的生态系统管理兼顾了保护和资源利用,需要考虑权衡和协同作用。季节性和适应性空间措施可减少渔业对非目标物种的影响,同时保持或增加目标渔获量。在开阔海洋中,动态环境条件驱动着物种分布的变化,识别这些区域中持续存在的高风险区域对于探索禁渔期的影响至关重要。我们利用 1995 年至 2021 年收集的渔业观测数据,探讨了两种大洋性鲨鱼--丝鲨(Carcharhinus falciformis)和大洋性白鳍鲨(Carcharhinus longimanus)--的高兼捕风险区域和低金枪鱼捕获率区域的时空持续性。我们分析了约 200 艘悬挂 10 种不同旗帜在欧大洋区域作业的大型围网渔船上的渔业科学观察员收集的数据。渔捞努力量、渔获量和兼捕渔获物数据分别按 1° × 1° 单元和按月进行空间和时间汇总。如果在整个研究期间关闭捕捞效率高的区域,并按比例重新分配渔获量以反映历史渔获量模式,每年的金枪鱼渔获量似乎增加了 1-11%,而丝鲨和大洋白鳍鲨的副渔获量分别减少了 10-19%和 9%。在渔捞努力量重新分配之前,绢鲨和大洋白鳍鲨的混获渔获量分别减少了21-41%和14%。我们的研究结果与之前的研究结果一致,并证明了在不影响目标金枪鱼物种捕获率的情况下,减少欧罗巴洲副渔获物的巨大潜力。这些结果还凸显了考虑新的动态和适应性管理措施的必要性,以更有效地实现保护和可持续开发东太平洋渔场资源的目标。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
Conservation Biology
Conservation Biology 环境科学-环境科学
CiteScore
12.70
自引率
3.20%
发文量
175
审稿时长
2 months
期刊介绍: Conservation Biology welcomes submissions that address the science and practice of conserving Earth's biological diversity. We encourage submissions that emphasize issues germane to any of Earth''s ecosystems or geographic regions and that apply diverse approaches to analyses and problem solving. Nevertheless, manuscripts with relevance to conservation that transcend the particular ecosystem, species, or situation described will be prioritized for publication.
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