School of BioSciences, University of Melbourne, Melbourne, Vic., Australia.
National Institute of Water and Atmospheric Research (NIWA, Christchurch, New Zealand.
Glob Chang Biol. 2021 Apr;27(7):1470-1484. doi: 10.1111/gcb.15490. Epub 2021 Jan 27.
Fisheries harvest has pervasive impacts on wild fish populations, including the truncation of size and age structures, altered population dynamics and density, and modified habitat and assemblage composition. Understanding the degree to which harvest-induced impacts increase the sensitivity of individuals, populations and ultimately species to environmental change is essential to ensuring sustainable fisheries management in a rapidly changing world. Here we generated multiple long-term (44-62 years), annually resolved, somatic growth chronologies of four commercially important fishes from New Zealand's coastal and shelf waters. We used these novel data to investigate how regional- and basin-scale environmental variability, in concert with fishing activity, affected individual somatic growth rates and the magnitude of spatial synchrony among stocks. Changes in somatic growth can affect individual fitness and a range of population and fishery metrics such as recruitment success, maturation schedules and stock biomass. Across all species, individual growth benefited from a fishing-induced release of density controls. For nearshore snapper and tarakihi, regional-scale wind and temperature also additively affected growth, indicating that future climate change-induced warming and potentially strengthened winds will initially promote the productivity of more poleward populations. Fishing increased the sensitivity of deep-water hoki and ling growth to the Interdecadal Pacific Oscillation (IPO). A forecast shift to a positive IPO phase, in concert with current harvest strategies, will likely promote individual hoki and ling growth. At the species level, historical fishing practices and IPO synergized to strengthen spatial synchrony in average growth between stocks separated by 400-600 nm of ocean. Increased spatial synchrony can, however, increase the vulnerability of stocks to deleterious stochastic events. Together, our individual- and species-level results show how fishing and environmental factors can conflate to initially promote individual growth but then possibly heighten the sensitivity of stocks to environmental change.
渔业捕捞对野生鱼类种群有着广泛的影响，包括体型和年龄结构的截断、种群动态和密度的改变以及栖息地和集合组成的改变。了解捕捞引起的影响在多大程度上增加了个体、种群，最终是物种对环境变化的敏感性，对于确保在快速变化的世界中实现可持续的渔业管理至关重要。在这里，我们生成了新西兰沿海水域和大陆架水域的四种商业重要鱼类的多个长期（44-62 年）、每年解析的体生长年表。我们利用这些新数据研究了区域和流域尺度的环境变异性与捕捞活动如何共同影响个体的体生长率以及种群之间的空间同步性的幅度。体生长的变化会影响个体的适应性以及一系列种群和渔业指标，如繁殖成功率、成熟计划和种群生物量。在所有物种中，个体的生长都受益于捕捞引起的密度控制的释放。对于近岸鲷鱼和竹荚鱼，区域尺度的风和温度也会附加地影响生长，这表明未来气候变化引起的变暖以及可能增强的风势将最初促进更靠近极地的种群的生产力。捕捞增加了深水鳕鱼和 Ling 生长对跨年代太平洋振荡（IPO）的敏感性。与当前的捕捞策略相结合，向正的 IPO 阶段的预测转变可能会促进鳕鱼和 Ling 的个体生长。在物种水平上，历史捕捞实践和 IPO 协同作用，加强了相距 400-600nm 海洋的种群之间平均生长的空间同步性。增加的空间同步性会增加种群对有害随机事件的脆弱性。总的来说，我们的个体和物种水平的结果表明，捕捞和环境因素如何最初促进个体生长，但随后可能会增加种群对环境变化的敏感性。
