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

静态生物能量模型计算作为年龄函数的个人或群体的能量需求。目前，对海洋哺乳动物最好的生物能量学模型是为Steller海狮构建的静态模型(Winship等人。2002年；Winship and Trites 2003)。这一模型将被改进和扩展，利用已公布的野生和圈养动物记录，预测加拿大和阿拉斯加主要海洋哺乳动物物种(海象、海豹、毛海豹、斯特勒海狮、虎鲸和白鲸)的食物需求。所需数据包括食物、猎物的生物学价值(可消化性和近似物组成)、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)以及估计年龄时的身体大小。这些模型将被用来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(例如，觅食成本、温度调节)而变化。这些模型将进一步用于开发动态生物能量模型，该模型包含对动物能量收支变化的生理反应(潜在范围)。动态模型将包含允许单个参数根据系统中的其他变化而改变的功能响应。动态生物能量模型是预测动物生物(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，并最终预测影响种群水平(存活率、繁殖率)的参数的最有用的手段。它们将与生境模型相结合，其中包括基于已公布的年龄和性别特定限制的可及性假设，以及使用各种物理变量(例如，水深、温度、盐度、冰盖、拉出地点)来区分可达性相等的地区的适宜性假设。估计海洋哺乳动物的食物消耗和能量需求，以及全球变暖对其活动范围分布的生物能量后果，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.