DSLCM

Delta Smelt Life Cycle Model (DSLCM)

Criterion

Explanation

General Description

The Delta Smelt Life Cycle Model is a Bayesian state-space model designed to assess and predict the effects of management actions on the delta smelt population, with the long-term goals of population recovery and sustainability. 

Model Domain

Sacramento-San Joaquin Delta. Western limit is mid San Pablo Bay.

Developer

US Fish and Wildlife Service

Hardware computing requirements

Not specified

Code language

R, JAGS

Original application

Assess and predict the effects of management actions on the delta smelt population, with the long-term goals of population recovery and sustainability. 

Public/proprietary and cost

Model was publicly funded but source code is not publicly available. No licensing costs reported.

Physically or empirically based

Empirical

Mathematical methods used

Recruitment modeled with Beverton-Holt model. Markov chain Monte Carlo (MCMC) used to generate samples of states and parameters from the conditional distribution. Stochastic Search Variable Selection (SSVS) used to search the space of candidate models for the best model.

Input data requirements

SWP and CVP salvage data used for estimating entrainment into water export facilities. Twenty millimeter survey, Fall Midwater Trawl, and Spring Kodaiak Trawl data used for estimating abundance of different life stages. DSM2 PTM used for modeling entrainment. Food, X2, outflow, and predators as covariates.

Outputs

Primary outputs are vital rates (juvenile recruitment, juvenile survival, and subadult survival), population growth, and change in population over time.

Pre-processing and post-processing tools

R scripts for pre-processing data are described in materials downloaded from DSLCM webpage but are not available from that webpage.

Representation of uncertainty

Stochasticity and uncertainty is explicit component of Bayesian state-space modeling.

Prevalence

There are numerous conceptual, statistical, and life cycle models for Delta Smelt. Community support has seemingly not coalesced around any one model, including the DSLCM.

Ease of use for public entities

The model uses advanced statistical techniques that would require training to understand.

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

The model framework is mature. Future work not explicitly described in available documentation.

Challenges for integration

No major barriers to integration

Model inventory developed for Delta Stewardship Council Integrated Modeling Steering Committee (IMSC)