Ecosystem management requires information on habitat condition across large scales; however, in Alaska comprehensive environmental surveys are often impractical and expensive to carry out. Intrinsic Potential (IP) models provide a means to identify at a large scale those portions of the landscape that can provide essential habitat for various fish species. These models are derived from watershed patterns and processes that operate at broad temporal scales and are not readily affected by human activities. We have developed an IP model for Chinook rearing habitat throughout the Copper River watershed in southcentral Alaska, utilizing existing digital elevation models, expert opinion, and field surveys. Our model uses only three variables: flow, gradient, and glacial influence. The model performs well, and is supported by independently gathered field survey and radio telemetry data for Chinook. This model will help resource managers map critical habitat for salmon throughout the Copper watershed, will help direct field research to appropriate stream reaches, and will assist managers in prioritizing restoration actions, such as culvert replacement. This type of modeling is broadly applicable and will also inform future research into the ecological impacts of climate change in Alaskan river systems.
