GrowChinook: an optimized multimodel and graphic user interface for predicting juvenile Chinook salmon growth in lentic ecosystems

Abstract

Linked foraging and bioenergetics models allow for increased understanding of fish growth potential and behavior by incorporating prey availability coupled to environmental conditions including temperature and prey visibility. To inform our understanding of growth and vertical migration patterns of Chinook salmon (Oncorhynchus tshawytscha) inhabiting lentic ecosystems, we linked foraging and bioenergetics models to create GrowChinook ( http://growchinook.fw.oregonstate.edu/ ). This multimodel design and optimization routine has broad applications in examining growth potential and predicting habitat use in stratified environments. We demonstrate the use of GrowChinook for the spring–summer rearing period in three Willamette River basin reservoirs, Oregon, USA. These reservoirs support juvenile spring Chinook salmon that exhibit a novel reservoir-reared life history that includes larger juvenile fish compared with nearby stream-reared subyearlings. Model outputs of predicted growth and depth use patterns based on observed prey distributions and environmental conditions were corroborated by observed empirical size and growth data from other years. Our simulations support diel vertical migration as a tactic that increases growth potential and contribute to understanding juvenile Chinook salmon growth in stratified systems.