Evaluating the Effectiveness of Fish Rescue Programs

A unique effort to seasonally translocate fish, termed “fish rescue”, has quietly emerged in the Pacific Northwest as a way to reduce drought related mortality in wild fish by manually moving individuals from fragmented areas to either free-flowing habitat or artificial rearing facilities, providing refuge during periods of low flow. Work supported by the Northwest CASC evaluates the potential costs and benefits of fish rescue by measuring the survival of wild juvenile coho salmon in fragmented tributaries of the Lewis River, WA. Working with stakeholders, researchers are developing a coho salmon life-cycle model that quantifies how survival across serial life-stages feeds back into population dynamics and how fish rescue mediates this process. This modeling framework will help managers assess the biological trade-offs and economic feasibility of fish rescue under varying contexts of drought.