Interagency Ecological Program and US Fish and Wildlife Service: San Francisco Estuary Enh

The Enhanced Delta Smelt Monitoring Program (EDSM) provides weekly fish population and environmental data for the upper San Francisco Estuary from 2016 onward. U.S. Fish and Wildlife Service field staff sample between 18 and 41 sites weekly using larval and Kodiak trawls, identifying and measuring fish while recording water temperature, conductivity, dissolved oxygen, turbidity, and depth. This long-term dataset tracks the endemic Delta Smelt and can be used to evaluate trends in other pelagic fish species.

Use Cases

• Modeling Delta Smelt population size and distribution based on stratified random sampling data.
• Analyzing seasonal and interannual trends in fish abundance from larval and juvenile/adult trawl records.
• Investigating relationships between fish presence and environmental variables like water temperature and turbidity.
• Assessing the status and trends of other pelagic fish species captured during monitoring.

Strengths

• Long-term monitoring spanning from 2016 to at least 2025, providing a multi-year time series.
• Systematic sampling design with 18 to 41 sites visited weekly, ensuring spatial and temporal coverage.
• Includes both biological data (fish identification, enumeration, length) and environmental measurements (temperature, conductivity, dissolved oxygen, turbidity, depth).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment for large-scale modeling.
• Data may reflect geographic bias inherent to the stratified random sampling design of the San Francisco Estuary.

Provenance

Source

U.S. Fish and Wildlife Service, Interagency Ecological Program

Collection Method

Field sampling via larval trawling in spring and Kodiak trawling in summer, fall, and winter at stratified random sites.

Time Range

2016-2025

Freshness

Last updated 2026-04-14 16:44:05.978564; freshness should be verified.

Geography

Upper San Francisco Estuary