Audubon Alaska, Anchorage, Alaska, United States of America.
Axiom Data Science, Anchorage, Alaska, United States of America.
PLoS One. 2019 Apr 17;14(4):e0214573. doi: 10.1371/journal.pone.0214573. eCollection 2019.
Recently available downscaled ocean climate models for the Bering Sea and Aleutian Arc offer the opportunity to assess climate vulnerability for upper trophic level consumers such as marine birds. We analyzed seasonal and annual spatial projections from three climate models for two physical climate variables (seawater temperature and sea ice) and three forage variables (large copepods, euphausiids, and benthic infauna), comparing projected conditions from a recent time period (2003-2012) to a future time period (2030-2039). We focused the analyses on core areas within globally significant Important Bird Areas, and developed indices of the magnitude of projected change and vulnerability agreement among models. All three climate models indicated a high degree of change for seawater temperature warming (highest in the central and eastern Aleutian Islands) and ice loss (most significant in the eastern Bering Sea) across scales, and we found those changes to be significant for every species and virtually every core area assessed. There was low model agreement for the forage variables; while the majority of core areas were identified as climate vulnerable by one or more models (72% for large copepods, 73% for euphausiids, and 94% for benthic infauna), very few were agreed upon by all three models (only 6% of euphausiid-forager core areas). Based on the magnitude-agreement score, euphausiid biomass decline affected core areas for fulmars, gulls, and auklets, especially along the outer shelf and Aleutian Islands. Benthic biomass decline affected eiders along the inner shelf, and large copepod decline was significant for storm-petrels and auklets in the western Aleutians. Overall, 12% of core areas indicated climate vulnerability for all variables assessed. Modeling and interpreting biological parameters to project future dynamics remains complex; the strong signal for projected physical changes raised concerns about lagged responses such as distribution shifts, breeding failures, mortality events, and population declines.
最近提供的白令海和阿留申群岛的细化海洋气候模型为评估上层营养级消费者（如海洋鸟类）的气候脆弱性提供了机会。我们分析了三个气候模型的两个物理气候变量（海水温度和海冰）和三个饲料变量（大型桡足类、磷虾和底栖无脊椎动物）的季节性和年度空间预测，将近期（2003-2012 年）和未来时期（2030-2039 年）的预测条件进行了比较。我们将分析重点放在具有全球重要意义的鸟类保护区的核心区域，并开发了模型间预测变化幅度和脆弱性一致性的指数。所有三个气候模型都表明，海水温度升高（在阿留申群岛中部和东部最高）和冰量减少（在白令海东部最为显著）的幅度很大，而且我们发现这些变化对每一种物种和几乎所有评估的核心区域都有重大影响。饲料变量的模型一致性较低；虽然大多数核心区域被一个或多个模型确定为气候脆弱区（大型桡足类的 72%、磷虾的 73%和底栖无脊椎动物的 94%），但很少有模型完全一致（只有 6%的磷虾觅食核心区）。根据幅度-一致评分，磷虾生物量下降影响了管鼻鹱、海鸥和海雀的核心区域，特别是在大陆架外和阿留申群岛。底栖生物量下降影响了内大陆架的绒鸭，而桡足类的下降对西部阿留申群岛的暴风鹱和海雀有重大影响。总的来说，12%的核心区域表示所有评估变量的气候脆弱性。建模和解释生物参数以预测未来动态仍然很复杂；预测的物理变化信号强烈，这引发了对分布转移、繁殖失败、死亡事件和种群减少等滞后反应的担忧。
