Comment: Larval Atlantic cod and haddock growth models, metabolism, ingestion, and temperature effects

Discussion 1960 In a rece t article, Leising and Franks (1999) presented detailed individual-based models (IBMs) for larval Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) based on the bioenergetic models of Laurence (1985) for the same species. Using these models, they drew conclusions on the effects of varying prey density, turbulence, and temperature on larval growth rate. However, an error in calculation of metabolism and their choice of a scalar for the effect of temperature on assimilation (Qa, their table 1) may require a revision of Leising and Franks’ (1999) conclusions. The error in estimation of daily metabolic rates originated in Laurence (1985) and was repeated in Werner et al. (1996). In this comment, we provide revisions for the estimation of metabolic costs and suggest that Qa for marine fish larvae should fall in the range of 1.06–1.14 based on our analysis of available literature. We also point to components of the model where compensating errors may occur and additional research is needed.