NSFGEO-NERC Collaborative Research: Effects of a Changing Climate on the Habitat Utilization, Foraging Ecology and Distribution of Crabeater Seals

第一部分：非技术描述：食蟹海豹是继100年前大型鲸鱼因人类捕杀而消失后，南极半岛西部海域最重要的南极磷虾捕食者。食蟹海豹数量多（约700万只），体型大（约700磅体重），新陈代谢高，以磷虾为主食，因此预计会消耗大量磷虾。这种海洋哺乳动物全年都依赖海冰的存在，生活、繁殖，并从这种环境中潜水觅食，这使得这种海洋哺乳动物成为南极生态系统如何应对气候变化的一个很好的指示器或哨兵。由于南极半岛北部的海冰一直在减少，该项目旨在了解在过去几十年里，这些物种的食物供应是否因环境变化而发生了变化。特别是，拟议的工作将集中在相隔450英里的南极半岛北部（即温暖的亚极地）和南部（即寒冷的极地）已知的食蟹海豹种群上，对这两个地点的食蟹海豹种群的丰度、生理、代谢需求和运动进行测量。这些数据将被结合起来建立模型，量化南北种群之间现有的差异，并预测它们未来的变化，并将目前的测量结果与20世纪中期英国南极调查局收集的数据进行比较。该项目是来自美国和英国的一个国际和跨学科团队之间的合作，有利于美国国家科学基金会促进涉及这两个国家的合作地球科学研究项目，并直接与美国全球变化研究计划（USGCRP）保持一致，以更好地了解塑造全球环境的力量，包括人类和自然，以及它们对社会的影响。为了进一步提高极地知识和教育水平，首席研究员将在两所美国机构培训至少两名研究生和几名本科生，以及一名英国博士后研究员。第二部分：技术描述：食蟹海豹（Lobodon carcinophaga）被认为是一个很好的哨兵物种，通过它可以研究气候变化对南极磷虾依赖捕食者群落和南极半岛西部整个生态系统结构的影响。近40年来，南极磷虾初级生产力的时空格局发生了显著变化，其种群动态也发生了显著变化。这种变化对全年居住的食蟹海豹（南极磷虾最重要的捕食者）的影响更难以理解，因为它们与繁殖种群无关，而繁殖种群的波动更容易被观察到。这项研究提出的前提是，由于海冰的不同减少及其对猎物可得性的可能影响，环境变化加剧了南极半岛北部和西南部食蟹海豹种群之间的差异。为了解决这个问题，本研究将结合动物运动测量、稳定同位素分析、全动物生理学和新型调查技术（小型无人机系统、卫星图像）来建立模型。该项目是来自美国和英国的一个国际和跨学科团队之间的合作。这些研究对于探测过去和预测未来，当将现在的测量数据与20世纪中期英国南极调查局收集的数据进行比较时，这些物种的生态变化对海冰变化的反应是至关重要的。为了进一步提高极地知识和教育水平，首席研究员将在两所美国机构培训至少两名研究生和几名本科生，以及一名英国博士后研究员。参与该项目的学生将获得宝贵的实验室研究经验，并将有一个独特的机会参加南极实地考察。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Part I: Non-technical description: The crabeater seal is the most important predator of Antarctic krill in the western Antarctic Peninsula oceanic waters after the disappearance of large whales due to human hunting 100 years ago. The crabeater seals are expected to consume large quantities of krill due to their high abundance (about 7 million individuals), large body size (about 700 pounds in body weight), high metabolism and a diet specializing in krill. This species depends on sea ice presence all year long, living, reproducing, and diving to feed from that environment, making this marine mammal species a good indicator, or sentinel, of how the Antarctic ecosystem responds to a changing climate. As sea ice has been decreasing in the northern Antarctic Peninsula, this project aims to understand if the species food availability has changed in the last decades in response to environmental changes. In particular, the proposed work will concentrate on known populations of crabeater seals in northern (i.e., warmer, sub-polar) and southern (i.e., colder, polar) Antarctic Peninsula, 450 miles apart, making measurements on the abundance, physiology, metabolic needs and movement of the crabeater populations in both locations. The data will be combined to build models that will quantify the existing differences between northern and southern populations, as well as predict their future change, and compare present-day measurements with those collected by the British Antarctic Survey in the mid-1900s. The project is a collaboration between an international and interdisciplinary team from the United States and United Kingdom, benefitting NSF goals to facilitate collaborative geoscience research projects involving these two countries as well as aligning directly with U.S. Global Change Research Program (USGCRP) to better understand the forces shaping the global environment, both human and natural, and their impacts on society. To further increase polar literacy and education, Principal Investigators will train at least 2 graduate students and several undergraduates across two US institutions, as well as one UK-based post-doctoral researcher.Part II: Technical description: Crabeater seals (Lobodon carcinophaga) are considered an excellent sentinel species through which to examine the effects of a changing climate on the extended Antarctic krill-dependent predator community and the structure of the entire ecosystem of the western Antarctic Peninsula. Over the last forty years, there have been significant changes in the temporal and spatial patterns of primary productivity, and shifts in the population dynamics of Antarctic krill, the dominant mid-trophic level species. The impact of such changes on year-round resident species of crabeater seals (the most important predator of Antarctic krill) is more difficult to understand as they are not associated with breeding colonies where their population fluctuations could be more readily observed. The proposed research is conceived under the premise that environmental change has accentuated the differences between the northern and southern western Antarctic Peninsula crabeater seal populations due to differential reductions in sea-ice and its possible effect on prey availability. To address this question, this research will combine measurements on animal movement, stable isotope analyses, whole-animal physiology, and novel survey technologies (small Unmanned Aircraft Systems, satellite imagery) to build models. The project is a collaboration between an international and interdisciplinary team from the United States and United Kingdom. These studies will be essential to detect past, and project future, changes in the ecology of this species in response to changes in sea ice when comparing present-day measurements with those collected by the British Antarctic Survey in the mid-1900s. To further increase polar literacy and education, Principal Investigators will train at least 2 graduate students and several undergraduates across two US institutions, as well as one UK-based post-doctoral researcher. Students involved with this project will gain invaluable research experience in the lab and will have a unique opportunity to participate in Antarctic fieldwork.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.