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：蟹海豹是100年前大型鲸鱼因人类狩猎而消失后，在南极半岛西部海域最重要的南极磷虾捕食者。由于蟹海豹丰度高(约700万只)、体型较大(体重约700磅)、新陈代谢能力强以及以磷虾为主食，预计它们将消耗大量磷虾。这种物种全年依赖海冰的存在，生活、繁殖和潜水从那个环境中觅食，使这种海洋哺乳动物物种成为南极生态系统如何应对不断变化的气候的良好指示器或哨兵。由于南极半岛北部的海冰一直在减少，该项目旨在了解物种的食物供应是否在过去几十年里因环境变化而发生了变化。特别是，拟议的工作将集中于相距450英里的南极半岛北部(即较温暖的亚极地)和南部(即较冷的极地)的已知蟹海豹种群，对这两个地点的蟹海豹种群的丰度、生理、代谢需求和活动进行测量。这些数据将被结合起来，以建立模型，量化南北人口之间的现有差异，并预测它们未来的变化，并将目前的测量结果与英国南极调查局在20世纪中期收集的数据进行比较。该项目是一个来自美国和英国的国际和跨学科团队的合作，使NSF的目标受益，以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(包括人类和自然)的力量及其对社会的影响。为了进一步提高极地文化和教育，首席调查人员将培训两个美国机构的至少两名研究生和几名本科生，以及一名驻英国的博士后研究人员。第二部分：技术说明：海豹被认为是一种优秀的哨兵物种，通过它可以研究气候变化对扩大的依赖于磷虾的南极捕食者群落和整个南极半岛生态系统结构的影响。在过去的40年里，初级生产力的时间和空间格局发生了重大变化，南极磷虾的种群动态发生了变化，这是中等营养层的优势物种。这种变化对常年栖息的蟹海豹(南极磷虾最重要的捕食者)物种的影响更难理解，因为它们与繁殖群体无关，在那里，它们的种群波动更容易观察到。这项拟议的研究是在这样一个前提下构思的：由于海冰的不同减少及其对猎物可获得性的可能影响，环境变化加剧了南极半岛北部和南部西南部蟹类海豹种群之间的差异。为了解决这个问题，这项研究将结合动物运动测量、稳定同位素分析、全动物生理学和新的调查技术(小型无人机系统、卫星图像)来建立模型。该项目是一个来自美国和联合王国的国际和跨学科小组之间的合作。当将现在的测量结果与英国南极调查局在20世纪中期收集的数据进行比较时，这些研究对于发现过去和预测未来该物种生态因海冰变化而发生的变化将是至关重要的。为了进一步提高极地读写能力和教育水平，首席调查员将培训两所美国机构的至少两名研究生和几名本科生，以及一名驻英国的博士后研究员。参与该项目的学生将在实验室获得宝贵的研究经验，并将有一个独特的机会参与南极实地考察。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.