FCVA logic model.

Climate change will continue to alter key physical and biological oceanographic processes throughout the global ocean, modifying environmental conditions for U.S. highly migratory fish species found in the Atlantic Ocean. The Atlantic Highly Migratory Species Climate Vulnerability Assessment evaluated the vulnerability of 58 species and stocks to projected ocean conditions, using a combined qualitative and quantitative analysis of species sensitivity (physiological, ecological, and behavioral attributes) and estimated exposure to possible future ocean stressors. Key modeled environmental variables included bottom and sea surface temperature, sea surface oxygen, and ocean acidification (pH), whereas the most influential biological attributes considered were population growth rate, stock size, and stock status. We produced vulnerability rankings (i.e., low, moderate, high, and very high) based on biological attribute sensitivity and exposure to the environmental variables, and separate analyses including estimated ability of distributional shifts, predicted directional effects of climate change, certainty, and data quality scores for the species and stocks assessed, with exceptions for species with undetermined geographic distributions. Of the 58 species and stocks assessed, 4 had very high vulnerability to climate change, 14 had high vulnerability, 22 had moderate vulnerability, 6 had low vulnerability, and 12 could not be assigned a rank. The majority (n = 45) of species and stocks had high ability for distributional shifts in response to projected changes in climate. Further, directional effect results suggest that climate change impacts on the majority of species and stocks will be neutral, implying that these species have life history or behavioral traits that impart some level of resilience and adaptability to the impacts of climate change. These results provide information for use in ecosystem-based fisheries management, particularly for prioritization of vulnerable species and stocks in conservation activities and research endeavors.

气候变化将持续改变全球海洋中关键的物理与生物海洋学过程，进而调整大西洋海域内美国高度洄游鱼类的生存环境条件。本次大西洋高度洄游物种（Atlantic Highly Migratory Species）气候脆弱性评估，针对58个物种与种群在未来预估海洋环境下的脆弱性展开研究，通过结合定性与定量分析的方法，评估了物种的敏感性（涵盖生理、生态及行为属性）以及其未来可能面临的海洋胁迫源暴露程度。本次评估选取的核心模拟环境变量包括海底温度、海表温度、海表溶解氧以及海洋酸化（ocean acidification）（pH值）；而被纳入考量的最具影响力的生物属性则包括种群增长率、种群规模与种群现状。研究团队基于生物属性敏感性与环境变量暴露程度，生成了脆弱性等级划分（即低、中、高、极高）；同时针对受评估物种与种群开展了独立分析，内容涵盖预估的分布迁移能力、气候变化的预测定向影响、确定性水平以及数据质量评分，但地理分布未明确的物种除外。在本次受评估的58个物种与种群中，4个物种/种群对气候变化的脆弱性为极高等级，14个为高等级，22个为中等级，6个为低等级，另有12个无法被赋予脆弱性等级。绝大多数（n=45）物种与种群具备较强的分布迁移能力，以应对预估的气候变化。此外，定向影响结果显示，气候变化对绝大多数受评估物种与种群的影响将呈中性，这意味着这些物种拥有相应的生活史或行为特征，使其能够在一定程度上抵御并适应气候变化带来的影响。本次研究结果可为基于生态系统的渔业管理（ecosystem-based fisheries management）提供决策支撑，尤其可用于在保护行动与科研工作中优先筛选脆弱物种与种群。