Use of Genetic Stock Identification Data for Comparison of the Ocean Spatial Distribution, Size at Age, and Fishery Exposure of an Untagged Stock and Its Indicator: California Coastal versus Klamath River Chinook Salmon

Authors

William H. Satterthwaite
Michael S. Mohr
Michael R. O'Farrell
Eric C. Anderson
Michael A. Banks
Sarah J. Bates
M. Rence Bellinger
Lisa A. Borgerson
Eric D. Crandall, California State University, Monterey BayFollow
John Carlos Garza
Brett J. Kormos
Peter W. Lawson
Melodie L. Palmer-Zwahlen

Document Type

Article

Publication Date

2014

Publication Title

Transactions of the American Fisheries Society

Abstract

Managing weak stocks in mixed-stock fisheries often relies on proxies derived from data-rich indicator stocks. For example, full cohort reconstruction of tagged Klamath River fall run Chinook salmon (Oncorhynchus tshawytscha) of northern California, USA, enables the use of detailed models to inform management. Information gained from this stock is also used in the management of the untagged, threatened California Coastal Chinook (CCC) salmon stock, by capping Klamath harvest rates. To evaluate use of this proxy, we used genetic stock identification (GSI) data to compare the two stocks' size-at-age and ocean distribution, two key factors influencing fishery exposure. We developed methods to account for both sampling and genetic assignment uncertainty in catch estimates. We found that, in 2010, the stocks were similar in size-at-age early in the year (age-3 and age-4), but CCC fish were larger later in the year. The stocks appeared similarly distributed early in the year (2010), but more concentrated near their respective source rivers later in the year (2010 and 2011). If these results are representative, relative fishery impacts on the two stocks might scale similarly early in the year but management changes later in the year might have differing impacts on the two stocks.

Comments

Preprint version. Published in Transactions of the American Fisheries Society, December 2013, pp. 117-133.

The final publication is available via http://dx.doi.org/10.1080/00028487.2013.837096

Recommended Citation

Satterthwaite, W.H., Mohr, M.S., O’Farrell, M.R., Anderson, E.C., Banks, M.A., Bates, S.J., Bellinger, M.R., Borgerson, L., Crandall, E.D., Garza, J.C., Kormos, B.J., Lawson, P.W., and M.L. Palmer-Zwahlen. 2014. Use of Genetic Stock Identification Data for Comparison of the Ocean Spatial Distribution, Size at Age, and Fishery Exposure of an Untagged Stock and Its Indicator: California Coastal versus Klamath River Chinook Salmon. Transactions of the American Fisheries Society, 143(1), 117-133. doi:10.1080/00028487.2013.837096