The fall Chinook salmon run in California's Central Valley, the most abundant run, has declined to record lows in 2007 and 2008 resulting in the closure of the fishery for the first time in its 100 year history. Coupled with recent findings indicating that in some years up to 90% of fall adult Central Valley salmon originate from hatcheries, a threatened listing for fall run Chinook may be imminent.
Artificial propagation of salmon in hatcheries has long played a role in meeting harvest and conservation goals for salmon and steelhead in California. However, a need to reform the hatchery system has been identified by scientists and policymakers based on growing concerns and scientific findings about the potential effects of hatcheries on the viability of salmon and steelhead in their natural habitats. Currently, all California's Central Valley salmon runs are listed as threatened, endangered or species of concern and more than 70% of spawning habitats have been lost or degraded as a result of mining activities, dam construction, and water diversions[4, 5].
In 2010, the U.S. Congress established and funded a hatchery review process in California because it recognized that the genetic resources to support a sustainable salmon fishery and recover at-risk runs of salmon were not being adequately managed using traditional hatchery practices . The goal of this hatchery program review initiative was to ensure that the hatchery programs were managed and operated to meet one or both of the primary purposes for hatcheries: (1) Helping recover and conserve naturally spawning salmon and steelhead populations, and (2) Supporting sustainable fisheries with little or no deleterious consequences to natural populations.
The science of hatcheries focuses on several key management concepts that if implemented would make a greater contribution to harvest than the existing natural habitat can sustain on its own . For integrated hatcheries one key element is managing hatchery and natural-origin fish as two components of a single gene pool that is locally adapted to the natural habitat. Opportunities to use science and monitoring to balance the role of hatcheries for harvest and conservation exist and are discussed by experts here.
1 Barnett-Johnson, R., C. Grimes, C. Royer, and C. Donohoe. 2007. Identifying the contribution of wild and hatchery Chinook salmon (Oncorhynchus tshawytscha) to the ocean fishery using otolith microstructure as natural tags. Canadian Journal of Fisheries and Aquatic Sciences 64:1683-1692. [PDF]
5 Yoshiyama, R. M., E. R. Gerstung, F. W. Fisher, and P. B. Moyle. 2001. Historical and Present Distribution of Chinook Salmon in the Central Valley Drainage of California. Pages 71-176 in R. L. Brown, editor. Contributions to the biology of Central Valley salmonids, Vol. 1. Fish Bulletin No. 179, Sacramento.
6 California Hatchery Scientific Review Group (California HSRG). 2012. California Hatchery Review Statewide Report. Prepared for the US Fish and Wildlife Service and Pacific States Marine Fisheries, Commission. April 2012. 100 pgs [PDF].
7 HSRG (Hatchery Scientific Review Group). 2014. On the Science of Hatcheries: An updated perspective on the role of hatcheries in salmon and steelhead management in the Pacific Northwest. A. Appleby, H.L. Blankenship, D. Campton, K. Currens, T. Evelyn, D. Fast, T. Flagg, J. Gislason, P. Kline, C. Mahnken, B. Missildine, L. Mobrand, G. Nandor, P. Paquet, S. Patterson, L. Seeb, S. Smith, and K. Warheit. June 2014 [PDF].