EPA created maps for six fish species that show changes in abundance and distribution as they relate to seasonal changes in the salinity gradient over a 33-year time period.  The maps visualize established salinity-abundance relationships and show how distribution has changed over time in the San Francisco Bay Delta Estuary.

The seasonal salinity gradient was simulated by the coarse-grid version of the UnTRIM San Francisco Bay-Delta Model and fish monitoring data are from the San Francisco Bay Study.

The maps show that the abundance of a number of fish species is higher when the low salinity zone is within or westward of Suisun Bay consistent with established science.

• Delta Smelt.pdf (PDF)(33 pp, 5 MB, July 2015)
  Seasonal salinity gradient and Delta smelt abundance and distribution from 1980-2012
• Longfin Smelt juvenile.pdf (PDF)(33 pp, 5 MB, July 2015)
  Seasonal salinity gradient and juvenile Longfin smelt abundance and distribution from 1980-2012
• Longfin Smelt.pdf (PDF)(33 pp, 5 MB, July 2015)
  Seasonal salinity gradient and longfin smelt abundance and distribution from 1980-2012
• Pacific Herring.pdf (PDF)(33 pp, 5 MB, July 2015)
  Seasonal salinity gradient and Pacific herring abundance and distribution from 1980-2012
• Sacramento Splittail.pdf (PDF)(33 pp, 5 MB, July 2015)
  Seasonal salinity gradient and Sacramento splittail abundance and distribution from 1980-2012
• Starry Flounder.pdf (PDF)(33 pp, 5 MB, July 2015)
  Seasonal salinity gradient and starry flounder abundance and distribution from 1980-2012
• Striped Bass.pdf (PDF)(33 pp, 5 MB, July 2015)
  Seasonal salinity gradient and striped bass abundance and distribution from 1980-2012