An individual-based simulation model for mottled sculpin (Cottus bairdi) in a southern Appalachian stream

We describe and analyze a spatially explicit, individual-based model for the local population dynamics of mottled sculpin (Cottus bairdi). The model simulated daily growth, mortality, movement and spawning of individuals within a reach of stream. Juvenile and adult growth was based on consumption bioenergetics of benthic macroinvertebrate prey; benthic macroinvertebrate densities were a function of flow, season, and habitat quality. We based mortality rates of individual sculpin on their condition. Fish movement was determined by a growth maximization rule. We adjusted selected parameters to calibrate the model for a sculpin population in a southern Appalachian stream, in terms of adult and juvenile abundance and mean adult weight and length. Sensitivity and correlation analysis of the calibrated model suggested that this population was regulated by overwinter density-dependence among juveniles and adults.