The request, which will be extended to other south Delta water diverters, was made after substantial reductions from the State Water Project failed to prevent the salvage of Delta smelt due to high tidal influences through June 3.
"Recent surveys indicate that Delta smelt abundance is at an all-time low," said DFG Director L. Ryan Broddrick. "These further extraordinary actions are necessary to protect Delta smelt that are currently extremely vulnerable to diversions in the south Delta."
DFG will contact other water diverters in the south Delta to request their cooperation in reducing or eliminating water diversions during this critical period. Up to 1,800 large and small diversions in the south Delta could be impacted.
Broddrick also announced that DFG would suspend all non-essential scientific collections of Delta smelt and work with scientists and other state and federal agencies to expand the use of brood stock to provide Delta smelt for scientific research purposes.
The measure would not affect monitoring of the abundance or location of Delta smelt, as this data allows the fishery agencies and independent scientists to be informed of potential actions to protect the smelt.