Salmon Hatchery Wars at an End?

Has the latest study of Pacific salmon ended the controversy generated by supplementing the population of wild coho salmon with hatchery raised coho salmon?

 The killing of hatchery raised coho salmon at the Fall Creek hatchery a number of years ago ignited the controversy over supplementing populations of wild coho salmon with hatchery raised salmon when a video clip of the hatchery raised coho salmon being clubbed to death was made public.  At the time State and Federal agencies were spending nearly 100 million dollars a year on hatchery produced salmon.  The study raises number of ongoing issues about the management practice of supplementing the wild population of wild salmonids with hatchery raised fish. 

The study, “Using an unplanned experiment to evaluate the effects of hatcheries and environmental variation on threatened populations of wild salmon” by Eric R. Buhle *, Kirstin K. Holsman, Mark D. Scheuerell, Andrew Albaugh at the National Marine Fisheries Service, Northwest Fisheries Science Center, 2725 Montlake Blvd E, Seattle, WA 98112, USA.  The National Marine Fishery Service administers NOAA’s programs which support the domestic and international conservation and management of living marine resources. 

The study concluded, “Efforts to conserve depleted populations of Pacific salmon (Oncorhynchus spp.) often rely on hatchery programs to offset losses of fish from natural and anthropogenic causes, but their use has been contentious. We examined the impact of a large-scale reduction in hatchery stocking on 15 populations of wild coho salmon along the coast of Oregon (USA). Our analyses highlight four critical factors influencing the productivity of these populations: (1) negative density-dependent effects of hatchery-origin spawners were _5 times greater than those of wild spawners; (2) the productivity of wild salmon decreased as releases of hatchery juveniles increased; (3) salmon production was positively related to an index of freshwater habitat quality; and (4) ocean conditions strongly affect productivity at large spatial scales, potentially masking more localized drivers. These results suggest that hatchery programs’ unintended negative effects on wild salmon populations, and their role in salmon recovery, should be considered in the context of other ecological drivers.”