【摘要】 南极大磷虾(Euphausia superba)是南大洋生态系统的关键种,也是重要的极地渔业目标种类。气候变化下,多种环境因素的复杂变化对南极磷虾分布带来不确定性影响。本研究采用KRILLBASE和GBIF数据库中1993—2016年夏季南极磷虾分布数据,选取海表面温度、海冰密集度、海表面盐度等9个环境参数,利用最大熵模型(MaxEnt)分析了夏季环南大洋南极磷虾分布与环境因子的关系,并预测了该群体当前及在未来气候情景下的夏季适生区分布及变动情况。结果表明,影响南极磷虾适生区分布的主要环境因子按贡献率高低依次为离陆架坡折距离、海冰密集度、海表面温度和海底深度,四者的累计贡献率超过90%。在极锋以南海域中,当前南极磷虾适生区总面积为1.3×10~7 km~2,占研究区域的40.44%,其中高适生区仅占适生区的12.53%。不同气候变化情景下,极锋以南海域南极磷虾适生区总体上呈现总面积减少、高适生区面积增加以及适生区重心向更高纬度移动的趋势,但不同扇区的变化趋势存在明显差异。在不同气候情景下,大西洋扇区各等级适生区的变化未见一致趋势;西印度洋和东印度洋扇区适生区总面积减少,但高适生区明显扩张;太平洋扇区适生区总面积增加,中适生区和高适生区明显扩张。本研究可为科学认知气候变化下南大洋南极磷虾栖息地变动以及南极磷虾科学养护与渔业管理提供参考。更多还原

【Abstract】 Antarctic krill(Euphausia superba) serves as a keystone species in the Southern Ocean ecosystem and is a key target of polar fisheries. Climate change induces complex variations in various environmental factors, leading to uncertainties in krill distribution. We assessed shifts in suitable habitats of Antarctic krill in response to climate change by utilizing distribution data from the KRILLBASE and GBIF databases(1993–2016, summer) and selecting nine environmental parameters, including sea surface temperature, sea ice concentration, and sea surface salinity, etc. The Maximum Entropy Model(MaxEnt) was employed to analyze the relationship between Antarctic krill distribution and environmental factors, evaluate current summer habitat suitability in the circumpolar Southern Ocean, and forecast future changes under various climate scenarios. The results showed that the primary influencing factors for Antarctic krill included distance to the shelf break, sea ice concentration, sea surface temperature, and bathymetry, with their cumulative contribution exceeding 90%. In the region south of the Polar Front, the current suitable habitat spanned 1.3×10~7 km~2, accounting for 40.44% of the study area, while high-suitability zones constituted merely 12.53% of the total suitable habitat. Under future climate scenarios, the total suitable habitat area decreases, with reductions in marginally and moderately suitable habitat and a significant expansion in highly suitable habitat. Sector-specific trends demonstrated substantial variability: the Atlantic sector exhibited the most sensitive changes with bidirectional fluctuations; the Western Indian and Eastern Indian sectors experienced overall reductions in suitable habitat but notable expansions in highly suitable habitat; and the Pacific sector revealed an increase in total suitable habitat, with significant growth in marginally and moderately suitable habitats. Additionally, the centroids of suitable habitats across all sectors shifted toward higher latitudes, indicating that climate change could be responsible for a poleward shift in krill distribution. These findings provide valuable insights into habitat dynamics of Antarctic krill in the Southern Ocean in the context of climate change, thereby supporting the scientific conservation and management of Antarctic krill fisheries.更多还原