Spatial and trophic overlap of marked and unmarked Columbia River Basin spring Chinook salmon during early marine residence with implications for competition between hatchery and naturally produced fish
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Ecological interactions between natural and hatchery juvenile salmon during their early marine residence, a time of high mortality, have received little attention. These interactions may negatively influence survival and hamper the ability of natural populations to recover. We examined the spatial distributions and size differences of both marked (hatchery) and unmarked (a high proportion of which are natural) juvenile Chinook salmon in the coastal waters of Oregon and Washington from May to June 1999–2009. We also explored potential trophic interactions and growth differences between unmarked and marked salmon. Overlap in spatial distribution between these groups was high, although catches of unmarked fish were low compared to those of marked hatchery salmon. Peak catches of hatchery fish occurred in May, while a prolonged migration of small unmarked salmon entered our study area toward the end of June. Hatchery salmon were consistently longer than unmarked Chinook salmon especially by June, but unmarked salmon had significantly greater body condition (based on length-weight residuals) for over half of the May sampling efforts. Both unmarked and marked fish ate similar types and amounts of prey for small (station) and large (month, year) scale comparisons, and feeding intensity and growth were not significantly different between the two groups. There were synchronous interannual fluctuations in catch, length, body condition, feeding intensity, and growth between unmarked and hatchery fish, suggesting that both groups were responding similarly to ocean conditions.
KeywordsColumbia River Basin Marine Juvenile Chinook salmon Spatial Trophic Competition Hatchery Wild
Support for our research is through the Bonneville Power Administration and we are grateful for their long term funding of our efforts. We also thank the members of the Estuarine and Ocean Ecology group including Bob Emmett, Bill Peterson and Ed Casillas from NMFS and Cheryl Morgan along with numerous others from OSU who assisted in field collections, laboratory analysis, and database creation. David Kuligowski and Don Van Doornik (NMFS) collected the genetics data used in this study and Kathy Cooper ran IGF-1 assays. Megan O’Connor (OSU) assisted with the R programming. We would also like to thank Bill Pearcy, Barry Berejikian, and two anonymous reviewers for their comments which greatly improved the manuscript.
- Beamish RJ, Mahnken C, Neville CM (1997) Hatchery and wild production of Pacific salmon in relation to large-scale natural shifts in the productivity of the marine environment. ICES J Mar Sci 54:1200–1215Google Scholar
- Brodeur RD, Fisher JP, Teel DJ, Emmett RL, Casillas E, Miller TW (2004) Juvenile salmonid distribution, growth, condition, origin, and environmental and species associations in the Northern California Current. Fish Bull 102:25–46Google Scholar
- Clarke KR, Warwick RM (2001) Change in marine communities: an approach to statistical analysis and interpretation 2nd edition. PRIMER-E Ltd, PlymouthGoogle Scholar
- Fish Passage Center (2005) Hatchery release database. Fish Passage Center, Northwest Power Planning Council. http://www.fpc.org/hatchery/Hatchery_Queries.html. Last accessed 16 May 2010
- Kalinowski ST, Manlove KR, Taper ML (2007) ONCOR A computer program for genetic stock identification. Department of Ecology, Montana State University, Bozeman, MT. www.montana.edu/kalinowski/Software/ONCOR.htm.
- Lichatowich JA (2001) Salmon without rivers: A history of the Pacific Northwest Salmon Crisis. Island, Washington, DCGoogle Scholar
- Miller TW, Brodeur RD (2007) Diet of and trophic relationships among dominant marine nekton within the Northern California Current ecosystem. Fish Bull 105:548–559Google Scholar
- National Marine Fisheries Service (NMFS) (2009) Endangered Species Act status of West Coast salmon and steelhead. www.nwr.noaa.gov Updated July 1, 2009
- National Research Council (1996) Upstream: Salmon and society in the Pacific Northwest. National Academy Press, Washington, D.CGoogle Scholar
- Nehlsen WJ, Williams JE, Lichatowich JA (1991) Pacific salmon at the crossroads: stocks at risk from California, Oregon, Idaho, and Washington. Fisheries 16:4–21Google Scholar
- Pearcy WG (1992) Ocean ecology of North Pacific salmonids. University of Washington Press, SeattleGoogle Scholar
- Pearcy WG, Fisher JP (1986) Migrations of coho salmon Oncorhynchus kisutch, during their first summer in the ocean. Fish Bull 86:173–195Google Scholar
- Quinn TP (2005) The behavior and ecology of Pacific salmon and trout. University of Washington Press, SeattleGoogle Scholar
- Ruggerone GT, Farley E, Nielsen J, Hagen P (2005) Seasonal marine growth of Bristol Bay sockeye salmon (Oncorhynchus nerka) in relation to competition with Asian pink salmon (O. gorbuscha) and the 1977 ocean regime shift. Fish Bull 103:355–370Google Scholar
- Seeb LW, Antonovich A, Banks MA, Beacham TD, Bellinger MR, Blankenship SM, Campbell MR, Decovich NA, Garza JC, Guthrie CM III, Lundrigan TA, Moran P, Narum SR, Stephenson JJ, Supernault KT, Teel DJ, Templin WD, Wenburg JK, Young SF, Smith CT (2007) Development of a standardized DNA database for Chinook salmon. Fisheries 32:540–552CrossRefGoogle Scholar
- Sweeting RM, Beamish RJ (2009) A comparison of the diets of hatchery and wild coho salmon (Oncorhynchus kisutch) in the Strait of Georgia from 1997–2007. North Pac Anadr Fish Comm Bull 5:255–264Google Scholar
- Trudel M, Fisher J, Orsi JA, Morris JFT, Theiss ME, Sweeting RM, Hinton S, Fergusson EA, Welch DW (2009) Distribution and migration of juvenile Chinook salmon derived from coded wire tag recoveries along the continental shelf of western North America. Trans Am Fish Soc 138:1369–1391CrossRefGoogle Scholar
- Zar JH (1999) Biostatistical analysis, 4th edn. Prentice-Hall International, LondonGoogle Scholar