Population Dynamics of Spiny Dogfish ( Squalus acanthias ) in British Columbia Waters

• Published in: Journal of the Fisheries Research Board of Canada
• Main Authors: Wood, C. C., Ketchen, K. S., Beamish, R. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1979
• Subjects: General Medicine; spiny dogfish; Squalus acanthias
• Online Access: http://dx.doi.org/10.1139/f79-094; http://www.nrcresearchpress.com/doi/pdf/10.1139/f79-094

An age-structure model that incorporates recent information regarding growth and reproduction has been developed to investigate the dynamics of spiny dogfish (Squalus acanthias) populations in British Columbia waters. Mechanisms for density-dependent regulation of abundance were evaluated on the basis of theoretical effectiveness and ability to predict observed patterns in simulations of the historical fishery. Compensatory change in the rate of natural mortality appears to be the principal mechanism for density-dependent response. The instantaneous rate of natural mortality at natural equilibrium was estimated to be 0.094 MSY for British Columbia waters is ~ 9000–11 000 t/yr. The minimum size at entry to the fishery has little effect on MSY. Sustained-effort, sustained-yield, and periodic fisheries were modeled to determine optimum harvesting strategies. Periodic fisheries were found to vary widely in feasibility and appear to be impractical from a management perspective whereas a sustained-effort fishery would ensure maximum stability. Key words: spiny dogfish, population dynamics, age-structure model, density-dependence, simulation model, commercial fishing strategies