Is density-dependent growth in young-of-the-year fishes a question of critical weight?

Authored by Kenneth A Rose, JH Cowan, DR DeVries

Date Published: 2000

Sponsors: United States Department of Energy (DOE) Electric Power Research Institute (EPRI) Oak Ridge National Laboratory (ORNL)

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

We develop a conceptual argument that density-dependent growth via reductions in prey resources are most likely to occur in the late-larval or juvenile stage in both marine and freshwater fishes. We use results from a suite of individual-based models and literature examples of a variety of marine, estuarine and freshwater species to provide evidence of the effects of age-0 fish on their prey. We conclude that larval-stage survival related to food-limited growth contributes significantly to recruitment variability. However, density-dependent regulation of cohort biomass via feedbacks derived from reductions in prey resources is most likely to occur at a ``critical-weight'' during the late-larval or juvenile stage. This occurs when fish densities remain relatively high, and population consumption is highest relative to prey density and replenishment rate. We compare our critical weight concept to Houde's (1997) critical size hypothesis.

Tags

Individual-based model Cod gadus-morhua Early-life stages Herring clupea-harengus Plaice pleuronectes-platessa Perch perca-flavescens Pollock theragra-chalcogramma Walleye stizostedion-vitreum Salmon oncorhynchus-keta Anchovy population-dynamics