Fall Midwater Trawl Survey [FMWT]
Description / purpose
The FMWT was initiated to determine the relative abundance and distribution of age-0 striped bass (Morone saxatilis), delta smelt (Hypomesus transpacificus), longfin smelt (Spirinchus thaleichthys), American shad (Alosa sapidissima), splittail (Pogonichthys macrolepidotus), and threadfin shad (Dorosoma petenense) in the estuary. FMWT has sampled annually since it's inception in 1967, with the exceptions of 1974 and 1979, when sampling was not conducted. The FMWT samples 122 stations each month from September to December and a subset of these data is used to calculate an annual abundance index.
The FMWT conducts compliance monitoring in collaboration with USBR and DWR to meet permit obligations to the SWRCB (and DRCB) via Water Rights Decisions (D-1485 and D-1641) and USFWS-NMFS biological opinions for Delta Smelt (Hypomesus transpacificus) and salmonids, and for incidental take permits issued by CDFW for operation of the State Water Project (SWP), and the USBR BA/ROD. FMWT also informs Natural Resource Agency Delta Smelt Resiliency Strategy management actions including the Suisun Marsh Salinity Control Gate re-operation and the North Delta Food Web Managed Flow actions. FMWT is used to inform Effects of Outflow Alteration upon Delta Smelt Habitat, Condition, and Survival and Summer-Fall Habitat Action monitoring.
Project Objectives
• To annually measure the abundance and distribution of selected species of pelagic fishes in the estuary.
• To gain understanding of the factors affecting abundance, distribution, and survival of pelagic fishes in the estuary.
• To detect introductions of new exotic fish and invertebrates.
• Provide baseline data to evaluate management plans and habitat restoration projects.
• To measure availability of fall planktonic food resources.
Linked science activities
None specifiedCollaborators
None specifiedActivity status
- 1 Awarded / Initiating (1994)
- 2 In progress / Ongoing (1994 - 2026)
- 3 Complete
Funding summary
Total allocated funding: $0
Location
Geographic tags
Products and outputs
| Type | Title | Description | Views |
|---|---|---|---|
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Fall Midwater Trawl Survey (FMWT) Data | Links to data for the FMWT | 0 |
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Fall Midwater Trawl Fact Sheet | Interagency Ecological Program 2026 Fact Sheet | 0 |
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Fall Midwater Trawl Bibliography | Annual Fish Abundance Summaries | 0 |