The longfin smelt, a finger-sized fish that once inhabited San Francisco Bay, has suffered such drastic declines that the federal government has determined the fish is in danger of extinction.
The U.S. Fish and Wildlife Service announced Monday that the Sacramento-San Joaquin River Delta and Bay Longfin Smelt population is now listed as endangered under the federal Endangered Species Act.
The longfin smelt is the sixth species of fish from the bay’s estuary to be added to the federal endangered species list. The fish was listed as a state threatened species in 2009.
Environmental group leaders said they hoped federal protections could help save the fish by placing additional restrictions on pumping water from the delta.
“For this fish to recover, we need to have more river flow so they can drain out of the delta,” said Jon Rosenfield, science director for the group San Francisco Baykeeper. “Their catastrophic decline is another sign that we are taking too much water from the rivers that feed the bay.”
The decision concludes a long process It began with a 2007 petition submitted by California environmental groups that involved several lawsuits.
Longfin Smelt at the UC Davis Bodega Marine Laboratory.
(Sam Briggs / Bodega Marine Laboratory)
Longfin smelts were once among the most abundant fish in the estuary, serving as an important food source for larger fish and birds, and for a time supporting a commercial fishery in the 1800s.
Since the 1980s, Rosenfield said, research indicates the population has declined by about 99 percent.
The U.S. Fish and Wildlife Service said in its announcement that the primary cause of the population decline was habitat loss, “primarily due to long-term reductions and alterations in freshwater flow into the San Francisco Bay Estuary.”
Paul Souza, the agency’s regional director, said the warmer, drier climate has contributed to the decline of longfin smelt.
“The species needs our help,” Souza said. “We are committed to working with others to conserve the longfin smelt.”
State and federal pumping facilities in the Delta, which send water flowing into the State Water Project and Central Valley Project aqueducts, are sometimes necessary to limit pumping to minimize losses of protected fish species.
Adding federal protections for longfin smelt “will ensure consistency between state and federal endangered species regulations,” the Fish and Wildlife Service said.
Rosenfield said Baykeeper and other groups will ensure the federal government implements science-based protections.
The longfin smelt lives in bays and estuaries along the Pacific coast.
They are typically 3.5 to 5 inches long, larger than the delta smelt, which is also on the endangered species list, and more tolerant of saltwater.
Although they live primarily in the estuary, longfin smelt can migrate to the ocean. They typically move to the delta during the winter and spring to spawn in freshwater areas.
Other fish species have also declined in the delta in recent years.
Investigations have revealed Decrease in the number of smelts in the delta in nature. Winter running Chinook salmon are endangered. And the fall chinook salmon fishing season has been cancelled the last two years due to the low population.
State officials are perform an examination to determine whether to protect the white sturgeon, North America’s largest freshwater fish, as an endangered species.
“The estuary is sending us multiple signals that we are taking too much water,” Rosenfield said.
“We need to divert less water, use it more sustainably and allow more of the water that flows out of the Sierra to flow through the delta,” he said. “And that would be done by reducing our demand for water, reducing agricultural demand and reducing municipal demand.”
Rosenfield said federal protections are long overdue. He helped write a petition calling on the federal government to protect the longfin smelt in 1992, when he was starting his career as a fish biologist, but that petition was rejected.
