Data from: A quantitative review of density-dependent growth and survival in salmonids: biological mechanisms, methodological biases, and management implications

Understanding the complex variation in patterns of density-dependent
individual growth and survival across populations is critical to adaptive
fisheries management, but the extent to which this variation is caused by
biological or methodological differences is unclear. Consequently, we
conducted a correlational meta-analysis of published literature to
investigate the relative importance of methodological and biological
predictors on the shape and strength of density-dependent individual
growth and survival in salmonids. We obtained 160 effect sizes from 75
studies of 12 species conducted between 1977-2019 that differed in
experimental approach (sensu Hurlbert, 1984; 65 laboratory experiments, 60
observational field studies, and 35 field experiments). The experimental
approach was the strongest factor influencing the strength of
density-dependence across studies: density-dependent survival was stronger
than growth in field observational studies, whereas laboratory experiments
detected stronger density-dependent growth than survival. The difference
between density-dependent growth and survival was minimal in field
experiments, and between lotic and lentic habitats. The shape of
density-dependence (logarithmic, linear, exponential, or
density-independent) could be predicted with 66.7% accuracy based solely
on the experimental approach and the density gradient (highest/lowest*100)
of the study. Overall, the strength and shape of density-dependence were
primarily influenced by methodological predictors, while biological
factors (predator presence, food abundance, and species) had predictable
but modest effects. For both empirical studies and adaptive fisheries
management, we recommend using field experiments with a density gradient
of at least 460% to detect the proper shape of the density-dependent
response, or accounting for potential biases if observational or
laboratory studies are conducted.