Estuaries and Coasts

, Volume 34, Issue 1, pp 120–128

Modeling the Effects of Future Outflow on the Abiotic Habitat of an Imperiled Estuarine Fish

  • Frederick Feyrer
  • Ken Newman
  • Matthew Nobriga
  • Ted Sommer

DOI: 10.1007/s12237-010-9343-9

Cite this article as:
Feyrer, F., Newman, K., Nobriga, M. et al. Estuaries and Coasts (2011) 34: 120. doi:10.1007/s12237-010-9343-9


Future development and climate change pose potentially serious threats to estuarine fish populations around the world. We examined how habitat suitability for delta smelt (Hypomesus transpacificus), a state and federally protected species, might be affected by changes in outflow in the San Francisco Estuary due to future development and climate change. Forty years of sampling data collected during fall from 1967 to 2008 were examined to define abiotic habitat suitability for delta smelt as a function of salinity and water transparency, and to describe long-term trends in habitat conditions. The annual habitat index we developed, which incorporated both quantity and quality of habitat, decreased by 78% over the study period. Future habitat index values under seven different development and climate change scenarios, representing a range of drier and wetter possibilities, were predicted using a model which related estuarine outflow to the habitat index. The results suggested that each of the scenarios would generally lead to further declines in delta smelt habitat across all water year types. Recovery targets for delta smelt will be difficult to attain if the modeled habitat conditions are realized.


Delta smelt Native fish Annual species Sacramento-San Joaquin Delta San Francisco Estuary Climate change Abiotic habitat Future development Generalized additive model 

Copyright information

© Coastal and Estuarine Research Federation (outside the USA) 2010

Authors and Affiliations

  • Frederick Feyrer
    • 1
  • Ken Newman
    • 2
  • Matthew Nobriga
    • 3
  • Ted Sommer
    • 4
  1. 1.Applied Science BranchUS Bureau of ReclamationSacramentoUSA
  2. 2.US Fish and Wildlife ServiceStocktonUSA
  3. 3.US Fish and Wildlife ServiceBay Delta Fish and Wildlife OfficeSacramentoUSA
  4. 4.DavisUSA

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