Topical Questions -- Types of Models: SacPAS Sacramento Prediction and Assessment of Salmon

Topical Questions

What can I explore to get a better sense of the different types of models on the SacPAS website?

There are different types of models, including simple calculations, statistical models, combinations of submodels, and mechanistic models. Below are some examples of the different types of models that report results on the SacPAS website. A few things you may want to think about are: 1) whether and how uncertainty is estimated and reported, 2) whether the model has the capacity to be updated with real-time data and also provide forecasts, and 3) whether different models answering the same question yield similar or different results and what that may mean.

Simple Calculations

Trends (e.g., 10-year trend by decade in SARs of coded-wire-tagged fish)
Data & Alerts CWT Smolt-to-Adult Ratio (SAR) Estimates
Averaged from historical data and extrapolated for forecasting in-season (e.g., Current Catch)
Data & Alerts Current Catch Unclipped Juveniles

Statistical Models

Mark-recapture Cormack-Jolly-Seber model to estimate survival
Data & Alerts CalFishTrack Survival Estimates
Mark-recapture modeling with time-varying covariates and temporally stratified multistate mark–recapture modeling to estimate survival, travel time, and routing (Perry et al. 2018; Hance et al. 2021)
Tools & Models Delta STARS

Tools & Models Fish Model Migration and Survival Modeling
Machine learning (quantile regression forest) to estimate loss and salvage (Tillotson et al. 2022)
Tools & Models Loss & Salvage Predictor

Combinations of Submodels

Model for forecasting the Juvenile Production Estimate that includes variance associated with observation error in the Juvenile Production Index, fry-to-smolt survival, and smolt survival (Method 2 in O’Farrell et al. 2018)
Data & Alerts JPE Letter Data
Total passage estimates at RBDD, model that includes trap efficiency modeling, estimated variance in weekly or biweekly sampling periods, and fry-equivalent estimates (Voss and Poytress 2023)
Data & Alerts Red Bluff Daily Table

Mechanistic Models

Biophysical model using lab-derived parameter estimates (Martin et al. 2017)
Tools & Models Fish Model Egg-to-Fry Modeling
Temperature-dependent mortality with thermal critical window (Anderson et al. 2022)
Tools & Models Fish Model Egg-to-Fry Modeling