Density-Dependent Growth in Salmonids: A Meta-analysis

The Salmonidae comprise a large group of ecologically and economically valuable species. We surveyed the published literature relating growth to density in salmonids, to perform a meta-analysis that tested for density-dependence. We obtained data from 45 studies that included 125 data sets for eight salmonids including Arctic Char, Atlantic Salmon, Brook Char, Rainbow Trout, Steelhead Trout, Brown Trout, Lahontan Cutthroat Trout, and Chinook Salmon. The random effects meta-analysis for species pooled showed an overall significant effect of density on growth (correlation = 0.58, z = − 15.18, p < 0.0001) although there was some heterogeneity among species (τ2 = 0.141, 95% CI −0.0660 – −0.1657). Individual species effects were all significant (95% CI for parameter estimates did not overlap zero), but the effect of density on the growth of Chinook Salmon was weaker than other species. Our analysis confirms previous work that density-dependent growth is common in members of the Salmonidae; a finding that should be incorporated into both management and conservation plans.