Habitat Utilization of Southern Ocean Seals: Foraging Behavior of Crabeater and Elephant Seals Using Novel Methods of Oceanographic Data Collection

作为长寿动物，海洋哺乳动物必须能够适应在大的空间和时间尺度上食物资源的广泛变化。虽然所有海洋哺乳动物都是如此，但南大洋的物理和生物环境变化尤其深刻。一个基本的了解觅食行为和栖息地利用的远洋捕食者需要这种空间和时间的变化，再加上他们如何应对这些变化的信息。目前对这些关联的理解主要限于种群水平的研究，其中动物丰度与海洋学相关。虽然这些研究是翔实的，他们不能提供洞察个别动物所采用的策略，也不能提供洞察这些相互作用的空间或时间过程。最近在仪器方面的技术进步使我们有可能超越猎物和捕食者分布与环境特征之间的简单联系。理解导致高捕食者丰度的过程的关键是识别与水柱不同特征相关的特定觅食行为。这项研究将通过结合准确的位置数据，潜水和觅食行为的措施，动物来源的水柱温度和盐度数据，以及现有的海洋学数据来实现这些目标。该项目将研究觅食行为和栖息地利用的两个物种的对比觅食生态，南象海豹，Mirounga leonina，和crabeater密封，Lobodon carcinophagus在南极西部半岛，一个地区的强环境梯度。虽然这两个物种在遗传学上是相关的，但它们利用了实质上不同但相邻的栖息地类型。南象海豹主要生活在远洋，在整个南大洋活动，偶尔会冒险进入季节性浮冰区，而食蟹海豹则在整个季节性浮冰区活动，偶尔会冒险进入开放水域。具体的觅食行为和动物运动模式与海洋学和测深学特征的关系，这些特征在确定生境利用方面的重要性的发展和测试模型，将沿着每个物种的个体如何对海洋环境的年度变化作出反应的比较。南大洋的物理海洋学具有内在的复杂性，与海洋学过程有内在联系的生物过程也是如此。目前正将大量资源用于开发物理海洋学过程的数学模型，目的是更好地了解南大洋在全球气候过程中的作用，预测海洋和全球尺度过程对气候变化的反应，并了解物理海洋学过程和生物海洋学过程之间的联系。这些努力受到该区域海洋学数据稀缺的限制，特别是在冬季高纬度地区。本研究将为进一步了解西南极半岛大陆架沃茨上层水体的动态提供新的、有意义的温盐剖面海洋学资料。外联活动包括网站开发和与蒙特雷湾水族馆研究所的海洋教育方案建立联系。

As long-lived animals, marine mammals must be capable of accommodating broad variations in food resources over large spatial and temporal scales. While this is true of all marine mammals, variation in the physical and biological environmental is particularly profound in the Southern Ocean. A basic understanding of the foraging behavior and habitat utilization of pelagic predators requires knowledge of this spatial and temporal variation, coupled with information of how they respond to these changes. Current understanding of these associations is primarily limited to population level studies where animal abundance has been correlated with oceanography. Although these studies are informative, they cannot provide insights into the strategies employed by individual animals nor can they provide insights into the spatial or temporal course of these interactions. Recent technological advances in instrumentation make it possible to extend an understanding beyond the simple linkage of prey and predator distributions with environmental features. The key to understanding the processes that lead to high predator abundance is the identification of the specific foraging behaviors associated with different features of the water column. This study will accomplish these objectives by combining accurate positional data, measures of diving and foraging behavior, animal-derived water-column temperature and salinity data, and available oceanographic data. This project will examine the foraging behavior and habitat utilization of two species of contrasting foraging ecology, the southern elephant seal, Mirounga leonina, and the crabeater seal, Lobodon carcinophagus in the Western Antarctic Peninsula, a region of strong environmental gradients. Although these two species are phylogenetically related, they utilize substantially different but adjacent habitat types. Southern elephant seals are predominantly pelagic, moving throughout the southern ocean, venturing occasionally into the seasonal pack ice whereas crabeater seals range throughout the seasonal pack ice, venturing occasionally into open water. The relationship of specific foraging behaviors and animal movement patterns to oceanographic and bathymetric features develop and test models of the importance of these features in defining habitat use will be determined along with a comparison of how individuals of each species respond to annual variability in the marine environment. The physical oceanography of the Southern Ocean is inherently complex as are the biological processes that are intrinsically linked to oceanographic processes. Significant resources are currently being directed toward developing mathematical models of physical oceanographic processes with the goals of better understanding the role that the Southern Ocean plays in global climate processes, predicting the responses of ocean and global scale processes to climate change, and understanding the linkages between physical and biological oceanographic processes. These efforts have been limited by the scarcity of oceanographic data in the region, especially at high latitudes in the winter months. This study will provide new and significant oceanographic data on temperature and salinity profiles in to further the understanding of the dynamics of the upper water column of west Antarctic Peninsula continental shelf waters. Outreach activities include website development and an association with a marine education program at the Monterrey Bay Aquarium Research Institute.