Delta STARS Model
Criterion | Explanation |
General Description | STARS = Survival, Travel Time, and Routing Simulation |
Model Domain | Eight reaches in the Sacramento-San Joaquin Delta. Simulated fish enter the model at Freeport and exit at Chipps Island. |
Developer | USGS, Western Fisheries Research Center, Quantitative Fisheries Ecology Section |
Hardware computing requirements | None specified |
Code language | R |
Original application | The STARS model simulates travel time, routing, and survival of individuals in a daily cohort as they migrate through eight unique reaches of the Delta. A daily cohort is defined as all fish that enter the Delta on a given day at Freeport. Because travel time, routing, and survival depends on river flow when an individual enters a given reach, overall survival of a daily cohort depends on the entire time series of daily flows during their migration time through the Delta. For example, two cohorts may enter the Delta at the same discharge, but their overall survival will differ if one cohort enters during an ascending hydrograph and the other enters when it descending. |
Public/proprietary and cost | Model is free to use through web interface (https://oceanview.pfeg.noaa.gov/shiny/FED/CalFishTrack/). |
Physically or empirically based | Empirical |
Mathematical methods used | The simulation model is based on a Bayesian multistate mark-recapture model with model parameters estimated as a function of time-varying individual covariates. |
Input data requirements | Daily time series of discharge and Delta Cross Channel gate operations |
Outputs | The Shiny App summarizes the output of each daily cohort for the current water year to display 1) overall survival and median travel time through the Delta between Freeport and Chipps Island, 2) route-specific survival and median travel time, and 3) the proportion of fish using each unique migration route. In addition to median travel time, users may also examine travel time distributions of daily cohorts or animate how travel time distributions change over time. Not currently possible to download outputs in tabular form through web interface; only provided as plots. |
Pre-processing and post-processing tools | Web interface is provided as post-processing tool |
Representation of uncertainty | Parameter set drawn from the joint posterior parameter distribution. Travel times drawn from a log-normal distribution where the mean of the distribution depends on the parameter set and discharge. Routing probabilities drawn from Bernoulli distributions as a function of discharge on the day each fish arrives at the junction. |
Prevalence | One peer-reviewed publication. No known uses in management or policy. |
Ease of use for public entities | The web interface makes interacting with the model very easy. |
Ease of obtaining information and availability of technical support | No user group or commercial help desk |
Source code availability | Source code is not publicly available |
Status of model development | Beta version. They plan to continually evolve the Shiny App to improve the user's experience. |
Challenges for integration | Model is in early stages of development. Source code is not available. Web interface does not provide outputs in tabular format. |