Evaluating the Potential Importance of Metapopulation Structure for the Conservation of Oncorhynchus Species

Although spatial structure is known to be of primary importance for species management, the metapopulation structure of anadromous fish populations is rarely considered. This project aims to fill this gap developing a new metapopulation model fitted from individual mark recapture data (PIT, CWT tags) using a Bayesian framework, which allows for the integration of expert opinion and results of previous work. The first goal of this project will be to estimate the importance of straying and spatial structure on population viability. Once developed, the new model will serve as a template to build a complete comprehensive life-cycle model that integrates the effects of different risk factors and environmental parameters (e.g., climate) over the entire salmon life cycle.

As case studies, we apply this framework to Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) populations from the Columba River, which are listed as endangered under the Endangered Species Act (ESA). It allows interesting comparisons of the importance of taking into account the metapopulation structure for different species present on the same river network.