Sacramento-san Joaquin delta habitat restoration

Recovery of six federal and state listed fish populations depends upon improving habitat conditions within the Sacramento San Joaquin Delta.  The decline in winter and spring-run Chinook salmon, steelhead, green sturgeon, and delta and long fin smelt populations has been attributed to major changes in the Delta’s hydrology, water quality, and geomorphology (i.e., fundamental estuarine dynamics).  Besides functionally changing habitat quality and quantity, the changes in the Delta’s environs have also allowed invasive species to take up new niches, altering the food web by increasing competition and predation, and further stressing these declining populations.

Federal and State agencies have initiated a habitat conservation planning effort to restore the Delta - to reestablish properly functioning habitats and conserve viable native fish populations.  A critical step to implementation of a successful plan is the effects analysis of the planned actions – simply, will these restoration activities work?  The approach to the analyses has integrated complex modeling of the Delta and its tributaries with the best available scientific understanding of the targeted fish populations.  Both the modeling and the science have evolved during the process, yet there are many uncertainties that will likely require an adaptive approach to restoration.