Collaborative Research: Determining Factors Affecting Distribution and Population Variability of the Ice-obligate Weddell Seal

威德尔海豹（Weddell seal）是世界上最南端的哺乳动物，分布在南极洲周围;南极洲的麦克默多湾（McMurdo Sound）种群是地球上研究得最好的哺乳动物种群之一。 然而，尽管如此，人们对非洲大陆各地的人口在气候变化下将如何发展的理解却知之甚少。一个复杂的问题是南极商业企业的潜在影响：一个以洋枪鱼为目标的渔业，这是威德尔海豹的重要猎物。虽然该物种在繁殖季节很容易被发现和计数，但由于调查南极洲广大地区的后勤困难，目前还没有可靠的估计。需要进行大规模的估计，以了解海豹种群如何应对渔业和气候变化，因为这些变化的驱动因素比任何单一种群都要大，可能会对该大陆不同地区的海豹产生不同的影响。我们将利用深色海豹在冰上容易被发现的优势，从卫星图像中估计它们的丰度。该项目将生成关于南极周围威德尔海豹全球分布和丰度的基线数据，并将环境变量与种群变化联系起来，以更好地了解该物种在海冰栖息地不断变化时的情况。这些结果将有助于理清气候变化和渔业作业的影响，这些结果对于制定有关渔业捕捞限制、对环境的影响和海洋保护区价值的适当国际政策是必要的。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。它将通过与几个非政府组织和公众的联系，使各个年龄段的“纸上谈兵”科学家参与进来。任何能够访问互联网的人，包括身体无法直接参与实地研究的人，都可以参与这个项目，同时通过该项目的互动网站了解极地生态学的多个方面。 具体而言，该研究项目将：1）量化南极洲周围威德尔海豹的分布，2）确定环境变量（如固定冰范围，海洋生产力，水深测量）对栖息地适宜性和占用的影响。为此，该项目将通过一个商业公民科学平台，在高分辨率卫星图像上对海豹进行众包计数。然后，通过广义线性模型将大陆周围海豹的变化与栖息地变量联系起来。将测试固定冰范围等具体变量，以确定它们在空间和时间上对种群变异性的影响。该项目包括一个严格的计划，以确保数据集的质量控制，包括来自其他本地化项目的地面实况数据，这些项目同时由美国国家科学基金会的南极科学计划资助。

The Weddell seal is the southern-most mammal in the world, having a circumpolar distribution around Antarctica; the McMurdo Sound population in Antarctica is one of the best-studied mammal populations on earth. However, despite this, an understanding of how populations around the continent will fare under climate change is poorly understood. A complicating matter is the potential effects of a commercial enterprise in the Antarctic: a fishery targeting toothfish, which are important prey for Weddell seals. Although the species is easily detected and counted during the breeding season, no reliable estimates of continent-wide Weddell seal numbers exist, due to the logistic difficulties of surveying vast regions of Antarctica. Large-scale estimates are needed to understand how seal populations are responding to the fishery and climate change, because these drivers of change operate at scales larger than any single population, and may affect seals differently in different regions of the continent. We will take advantage of the ease of detectability of darkly colored seals when they the on ice to develop estimates of abundance from satellite images. This project will generate baseline data on the global distribution and abundance of Weddell seals around the Antarctic and will link environmental variables to population changes to better understand how the species will fare as their sea ice habitat continues to change. These results will help disentangle the effects of climate change and fishery operations, results that are necessary for appropriate international policy regarding fishery catch limits, impacts on the environment, and the value of marine protected areas. The project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. It will engage "arm-chair" scientists of all ages through connections with several non-governmental organizations and the general public. Anyone with access to the internet, including people who are physically unable to participate in field research directly, can participate in this project while simultaneously learning about multiple aspects of polar ecology through the project's interactive website. Specifically, this research project will: 1) Quantify the distribution of Weddell seals around Antarctica and 2) Determine the impact of environmental variables (such as fast ice extent, ocean productivity, bathymetry) on habitat suitability and occupancy. To do this, the project will crowd-source counting of seals on high-resolution satellite images via a commercial citizen science platform. Variation in seal around the continent will then be related to habitat variables through generalized linear models. Specific variables, such as fast ice extent will be tested to determine their influence on population variability through both space and time. The project includes a rigorous plan for ensuring quality control in the dataset including ground truth data from other, localized projects concurrently funded by the National Science Foundation's Antarctic Science Program.