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大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，但在南大洋，物理和生物环境的变化尤其深刻。对远洋捕食者的觅食行为和栖息地利用的基本了解需要了解这种时空变化，以及它们如何应对这些变化的信息。目前对这些关联的理解主要局限于种群水平的研究，其中动物丰度与海洋学相关。尽管这些研究提供了信息，但它们不能提供对单个动物所采用的策略的见解，也不能提供对这些相互作用的空间或时间过程的见解。最近在仪器仪表方面的技术进步使人们有可能超越对猎物和捕食者分布与环境特征的简单联系的理解。了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精确的位置数据、潜水和觅食行为的测量、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。本项目将在环境梯度较强的南极半岛西部研究两种截然不同的觅食生态物种——南象海豹（miounga leonina）和食蟹海豹（Lobodon carcinophagus）的觅食行为和栖息地利用。虽然这两个物种在系统发育上是相关的，但它们利用的栖息地类型却截然不同。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，而食蟹海豹则在整个季节性浮冰范围内活动，偶尔会冒险进入开阔水域。具体的觅食行为和动物运动模式与海洋学和深海特征的关系，开发和测试这些特征在定义栖息地使用方面的重要性的模型，将与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一起确定。南大洋的物理海洋学本身就很复杂，与海洋学过程有着内在联系的生物过程也是如此。目前，大量资源正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所起的作用，预测海洋和全球尺度过程对气候变化的响应，并了解物理和生物海洋学过程之间的联系。这些努力受到该区域海洋数据匮乏的限制，特别是在冬季的高纬度地区。本研究将为进一步认识南极半岛西部大陆架水域上层水柱的动力学提供新的、有意义的温度和盐度剖面资料。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项目的合作。

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.