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How many Delta Smelt Remain?

Because Delta smelt are now rarely being captured in regular CDFW fish surveys, the US Fish and Wildlife Service began the Enhanced Delta Smelt Monitoring Program (EDSM) in 2017.  Results for the first four years show adult Delta smelt are still around in winter spawning season – barely (Figure 1).  They continue to be found throughout the northern Delta and Suisun Bay/Marsh (Figure 2).  Hotspots (likely spawning concentrations) were in west Delta near Rio Vista and the Deepwater Ship Channel.  Juveniles continue to show up in EDSM summer surveys in the usual places (Figure 3).  There may be a few thousand adult Delta smelt left as of 2019/2020 based on US Fish and Wildlife Service estimates.

Figure 1. Catch of adult Delta smelt in winter EDSM Kodiak trawl surveys 2017-2020.

Figure 2. Locations where Delta smelt adults were captured in EDSM surveys in winter 2019 (yellow dots) and 2020 (green dots).

Figure 3. Locations where Delta smelt young were captured in EDSM surveys in July 2019. Circles represent regions. Numbers are total July catch in region. The 94 represents the young smelt captured in the Deepwater Ship Channel.