Numerical Integration of Temperature‐Dependent Functions in Bioenergetics Models to Avoid Overestimation of Fish Growth

AbstractThe Wisconsin bioenergetics model is widely used to evaluate the effects of environmental conditions, trophic interactions, and human-mediated alterations to physical and trophodynamic processes on the growth and survival of individual fish species. In particular, bioenergetics models are increasingly applied to evaluate conditions that vary on subdaily time steps, such as vertical migrations that influence thermal experience and fluvial alterations that increase diurnal temperature variability. However, because the algorithms that describe the relationship between temperature and physiological rates are often nonlinear, using inputs of daily mean temperatures can result in underestimation or overestimation of growth and energetic demand. We used simulations of daily and subdaily models of Chinook Salmon Oncorhynchus tshawytscha as an example to demonstrate that the nonlinear, temperature-dependent algorithms for consumption and respiration induce large differences in growth between constant- and ...