From Rivers to the Ocean: Using Coupled Physical and Biological Models to Drive a Salmon Life Cycle Model

Throughout their life history, Sacramento River Chinook salmon use a diversity of ecosystems, including the river itself, the San Francisco Bay-Delta, and the Pacific Ocean. This poses a significant challenge to our understanding of their population dynamics, because habitat conditions in one ecosystem and life-stage can have consequences that manifest in the following ecosystem and life stage. Salmon models therefore need to capture the habitat variability in each ecosystem and incorporate the critical linkages between ecosystems. The Salmon Ecosystem Simulation And Management Evaluation (SESAME) project aims to address these issues by using a series of coupled physical-biological simulations to produce key habitat variables in each system. For the Sacramento River we are coupling the RAFT (River Assessment for Forecasting Temperature) model with the AQUATOX ecosystem model. For the SF Bay/Delta we are coupling SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) and the CoSiNE ecosystem model. For the Pacific Ocean we are using ROMS and CoSiNE. We will use the habitat variables (water temperature, water flow velocity, and food density) from these models to drive a Dynamic Energy Budget (DEB) model for Chinook salmon to explore how salmon grow from eggs to mature adults while moving across this complex landscape.