UC Davis Fish Biologist: Delta Smelt "Functionally Extinct" Wednesday, March 18, 2015 | Sacramento, CA Listen / download audio Update RequiredTo play audio, update browser or Flash plugin. All of California’s native fish species are suffering in the drought but Delta smelt populations may be so depleted the species won’t be able to come back. These findings have led UC Davis Fish Biologist Peter Moyle to say it’s time to prepare for the extinction of the Delta smelt. The latest state trawl in the Sacramento/San Joaquin Delta collected only six of the endangered fish. But the US Fish and Wildlife Service says it’s too soon to throw out the term “extinction.” Joining us to explain what’s happening to smelt populations is Peter Moyle, associate director of the Center for Watershed Sciences at UC Davis. We’ll also speak with Carl Wilcox from the California Department of Fish and Wildlife. He can explain what happens next with the fish species.