Simple dynamics underlie sockeye salmon (oncorhynchus nerka) cycles

Myers, Ransom A. and Mertz, Gordon and Bridson, Jessica M. and Bradford, Michael J. (1998) Simple dynamics underlie sockeye salmon (oncorhynchus nerka) cycles. Canadian Journal of Fisheries and Aquatic Sciences, 55 (10). pp. 2355-2364. ISSN 1205-7533

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Abstract

A variety of mechanisms have been proposed to explain the renowned British Columbia sockeye salmon (Oncorhynchus nerka) cycles, most of which invoke between-brood interactions (delayed density dependence) or depensatory harvest practices. We examine the dynamics of the Ricker model with realistic parameter values and suggest that the cycles could result from a stable mode excited by stochastic forcing. The previously proposed mechanisms are not required to generate cyclic patterns, although they could play a role in reinforcing cycles. Our results suggest that relaxing harvest rates will increase yields and decrease variability in sockeye abundances.

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