© California Dept. of Fish and WildlifeFish species ranging from endangered Delta Smelt to Striped Bass continued to plummet to record low population levels in 2015 in the Sacramento-San Joaquin River Delta, according to the annual fall survey report released on December 18 by the California Department of Fish and Wildlife.
Only 6 Delta Smelt, an endangered species that once numbered in the millions and was the most abundant fish in the Delta, were collected at the index stations in the estuary this fall. The 2015 index (7), a relative number of abundance, "is the lowest in history," said Sara Finstad, an environmental scientist for the CDFW's Bay Delta Region.
The Delta Smelt, a 2 to 3 inch fish found only in the San Francisco Bay-Delta Estuary, is an indicator species that demonstrates the health of the Delta, an
estuary that has been dramatically impacted by water exports to corporate agribusiness interests and Southern California water agencies during the record drought, along with other factors including increasing water toxicity and invasive species.
The Fall Midwater Trawl Survey, used to index the fall abundance of pelagic (open water) fishes most years since 1967, conducts monthly surveys from September through December. The 2015 sampling season was completed on December 11.
"In September, the only Delta Smelt collected were from index stations in the lower Sacramento River," said Finstad. "In October the only Delta smelt collected came from a non-index station in the Sacramento Deep Water Shipping Channel."
In November, no Delta Smelt were collected - and in December, the only Delta Smelt collected were from index stations in Montezuma Slough and the lower Sacramento River, according to Finstad.
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