Assemblage-wide effects of Ocean Acidification and Ocean Warming on Ecologically important Macroalgal-associated Crustaceans in Antarctica

海底海藻林占据了南极洲西部半岛中部和北方海岸的浅水沃茨，为许多海洋生物提供了重要的结构性栖息地和碳资源（食物）。大多数海藻在化学上防御食草动物，但支持非常高密度的食草虾类食草动物（甲壳类动物，主要是端足类动物），这些食草动物通过消耗丝状和微观藻类而大大有益于它们的宿主，否则海藻会过度生长。片脚类动物受益于与化学防御海藻的联系，获得了一个免受鱼类捕食的联系避难所。该项目的基础是最近的工作，这些工作表明，作为与海藻有关的甲壳类动物组合的关键成员的几种端足类动物在长期暴露于代表不久的未来海洋的海水酸度增加（pH值降低）和温度升高时，会遭受严重死亡。通过在南极洲帕尔默站的实验室中模拟这些环境条件，研究人员将测试海洋酸化和海洋变暖将在构建与海藻相关的甲壳类动物组合方面发挥重要作用的总体假设。 更广泛的影响包括扩大对全球气候变化影响的基本知识，重点关注地球上特别易受气候变化影响的地理区域。 该项目还将进一步推动NSF培养新一代科学家和向公众提供科学发现的目标。 这包括培训研究生和早期职业科学家，重点是多样性，向K-12团体和公众介绍，以及各种基于社交媒体的推广计划。 该项目将比较自然（环境）、二氧化碳富集和高温海水对海藻相关甲壳类食草动物组合的人口和组合范围的影响。 根据先前的结果，在变化的条件下，一些物种可能是相对的“赢家”，一些物种将是相对的“输家”。然后，该项目将旨在对两个关键的片脚类“赢家”和两个关键的片脚类“输家”的生长、钙化、矿物学、蜕皮发生率以及生物化学和能量身体组成进行测量。这些测量结果将有助于评估在海洋酸化和海面变暖的条件下，哪些因素导致特定物种的性能增强或减弱。该项目将扩大人们对南极洲海底海洋甲壳动物的条件变化的预期影响所知甚少的内容，这是一个面临蜕皮的额外生理压力的分类群体。 该项目可能会提供额外的洞察力的间接调节海藻，构成南极海底森林，提供沿海海洋生态系统的关键建筑组件。该奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

Undersea forests of seaweeds dominate the shallow waters of the central and northern coast of the western Antarctic Peninsula and provide critical structural habitat and carbon resources (food) for a host of marine organisms. Most of the seaweeds are chemically defended against herbivores yet support very high densities of herbivorous shrimp-like grazers (crustaceans, primarily amphipods) which greatly benefit their hosts by consuming filamentous and microscopic algae that otherwise overgrow the seaweeds. The amphipods benefit from the association with the chemically defended seaweeds by gaining an associational refuge from fish predation. The project builds on recent work that has demonstrated that several species of amphipods that are key members of crustacean assemblages associated with the seaweeds suffer significant mortality when chronically exposed to increased seawater acidity (reduced pH) and elevated temperatures representative of near-future oceans. By simulating these environmental conditions in the laboratory at Palmer Station, Antarctica, the investigators will test the overall hypothesis that ocean acidification and ocean warming will play a significant role in structuring crustacean assemblages associated with seaweeds. Broader impacts include expanding fundamental knowledge of the impacts of global climate change by focusing on a geographic region of the earth uniquely susceptible to climate change. This project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This includes training graduate students and early career scientists with an emphasis on diversity, presentations to K-12 groups and the general public, and a variety of social media-based outreach programs. The project will compare population and assemblage-wide impacts of natural (ambient), carbon dioxide enriched, and elevated temperature seawater on assemblages of seaweed-associated crustacean grazers. Based on prior results, it is likely that some species will be relative "winners" and some will be relative "losers" under the changed conditions. The project will then aim to carry out measurements of growth, calcification, mineralogy, the incidence of molts, and biochemical and energetic body composition for two key amphipod "winners" and two key amphipod "losers". These measurements will allow an assessment of what factors drive species-specific enhanced or diminished performance under conditions of ocean acidification and sea surface warming. The project will expand on what little is known about prospective impacts of changing conditions on benthic marine Crustacea, in Antarctica, a taxonomic group that faces the additional physiological stressor of molting. The project is likely to provide additional insight on the indirect regulation of the seaweeds that comprise Antarctic undersea forests that provide key architectural components of the coastal marine ecosystem.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.