Effects of climate change on the distribution and energy requirements of marine mammals

静态生物能量模型计算个体或群体的能量需求作为年龄的函数。目前，最好的海洋哺乳动物生物能量模型是为斯特勒海狮构建的静态模型（Winship et al. 2002; Winship and Trites 2003）。这个模型将被完善和扩展，以预测加拿大和阿拉斯加主要海洋哺乳动物物种的食物需求（海象、斑海豹、毛皮海豹、虎头海狮、虎鲸和白鲸），使用来自野生动物和圈养动物的公开记录。所需的数据包括饮食、猎物的生物学价值（消化率和近似组成）、觅食成本（寻找食物的能量和时间）、能量需求（总能量和特定活动的能量）以及估计年龄时的体型。这些模型将用于估计这些物种的食物需求将如何随着猎物基础和物理环境的变化而变化（例如，觅食成本，体温调节）。这些模型将进一步用于开发动态生物能量模型，其中包括动物能量预算变化的生理反应（潜在范围）。动态模型将包含功能响应，允许单个参数根据系统中的其他变化而变化。动态生物能量模型是预测动物的生物（鱼类分布）和非生物（温度、冰盖）环境变化对其行为和生理的影响，并最终影响种群水平（存活率、繁殖率）的参数的最有用的手段。它们将与栖息地模型相结合，这些模型结合了基于已公布的年龄和性别特定限制的可达性假设，以及使用各种物理变量（例如，水深、温度、盐度、冰盖、搬运地点）的适宜性假设，以区分具有同等可达性的区域。估计海洋哺乳动物的食物消耗和能量需求，以及全球变暖对其范围分布的生物能量影响，对渔业管理具有理论意义和实际应用。

Static bioenergetic models calculate the energy requirements of an individual or population as a function of age. Currently, the best bioenergetic model for marine mammals is a static model constructed for Steller sea lions (Winship et al. 2002; Winship and Trites 2003). This model will be refined and expanded to predict food requirements of key species of marine mammals in Canada and Alaska (walruses, harbour seals, fur seals, Steller sea lions, killer whales and beluga whales) using published records from wild and captive animals. Data required include diet, biological value of prey (digestibility and proximate composition), foraging costs (energy and time to find food), energy requirements (total and activity-specific), and body size at age estimates. These models will be used to estimate how food requirements for these species will change in response to changes in the prey base and physical environment (e.g., foraging cost, thermoregulation). The models will be further used to develop dynamic bioenergetic models that incorporate the physiological responses (potential range) to changes in animals' energy budgets. The dynamic models will incorporate functional responses that permit individual parameters to change in accordance with other changes in the system. Dynamic bioenergetic models are the most useful means of predicting the effects of changes in an animal's biotic (fish distribution) and abiotic (temperature, ice cover) environment on its behavior and physiology, and ultimately on parameters that impact population levels (survival, reproduction rates). They will be combined with habitat models that incorporate accessibility assumptions based on published age and sex specific constraints, as well as suitability assumptions that use a variety of physical variables (e.g., bathymetry, temperature, salinity, ice cover, haulout sites) to differentiate between regions of equal accessibility. Estimates of the food consumption and energy requirements of marine mammals, and the bioenergetic consequences of global warming on their range distributions have theoretical implications and practical applications for fisheries management.