Energy dynamics of Chinook salmon as they migrate from rivers to the ocean

During the migration from their freshwater habitats of rivers to the ocean, juvenile Chinook salmon encounter substantially different abiotic and biotic conditions. These differences in conditions in can have important consequences for growth, condition (lipid storage), and survival. We developed a generic energetic model based off Dynamic Energy Budget theory that characterizes growth and energy allocation dynamics as a function of biotic (food density) and abiotic (water temperature) conditions. We then linked the bioenergetics model with coupled physical-biological models of river, estuary, and ocean habitats to predict energy dynamics before, during, and after the transition to ocean environments. The analysis of our model yielded novel insights about energy partitioning between growth and storage lipids as a function of food density. Furthermore we used the model to identify physical conditions associated with fast growth and high survival in the first few months in the ocean, a critical transition in the salmon life cycle.