The Cost of Hatchery Straying: An Economic Case Study on Alaska Pink Salmon

Augmenting harvest using hatchery-produced salmon relies on fish returning to intended sites for capture. However, not all do – some stray, evading capture and entering wild spawning grounds, thus representing foregone yield. Here we ask, “what is the theoretical loss to harvesters as a result of straying?” We applied existing stray estimates and ex-vessel values from the world’s largest pink salmon hatchery-fishery program: Prince William Sound, Alaska, across three return years with full accounting of system wide harvest, escapement, and straying, to examine the value of strays under a range of scenarios that varied the component of the harvesting sector that might catch strays. In this system, approximately 1-5% of returning hatchery fish are estimated to stray away from release sites, which translates to approximate 0.8 - 4.5 million fish. We found that these strays were worth between $1 and $8 million per year, depending on the scenario and harvest year examined. While many important assumptions factor into this evaluation, our intention is for this work to spark dialogues about the economic tradeoffs associated with investing in stray reduction technologies, complementing the well-studied eco-evolutionary costs and benefits of straying.