The longfin smelt, a finger-sized fish that once filled San Francisco Bay, has suffered such a drastic decline that the federal government has determined the fish is at risk of extinction.
The U.S. Fish and Wildlife Service announced Monday that the longfin smelt population in the Sacramento-San Joaquin Bay and River Delta is now listed as endangered under the federal Endangered Species Act.
The longfin smelt is the sixth species of fish from the Bay estuary to be added to the federal endangered species list. The state placed the fish on the threatened species list in 2009.
Environmental group leaders said they hope federal protections could help save the fish by imposing additional restrictions on pumping water from the delta.
“For this fish to recover, more river flow needs to be drained from 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 which began with a petition filed in 2007 by California environmental groups and involved several lawsuits.
Longfin smelt at the UC Davis Marine Laboratory Cellar.
(Sam Briggs/Bodega Marine Laboratory)
The long-finned sense of smell was 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 19th century.
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 has been 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 warmer, drier weather has contributed to the decline of the long-finned smelt.
“The species needs our help,” Souza said. “We are committed to working with others to conserve the long-finned smelt.”
State and federal pumping facilities in the delta, which send water to the State Hydraulic Project and Central Valley Project aqueducts, are sometimes It is necessary to limit pumping to minimize losses of protected fish species.
Adding federal protections for the long-finned smelt “will provide consistency between state and federal regulations on endangered species,” the Fish and Wildlife Service said.
Rosenfield said Baykeeper and other groups will be vigilant to ensure the federal government implements science-based protections.
The longfin smelt lives in bays and estuaries along the Pacific coast.
Typically measuring 3.5 to 5 inches long, they are larger than delta smelts, which are also on the endangered species list, and are more tolerant of ocean water.
While they live primarily in the estuary, longfin smelts 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 suffered declines in the delta in recent years.
Surveys have found that Decreased number of delta olfactory In the wild. Winter race Chinook Salmon are in danger of extinction. And the fall king salmon fishing season is over. cancelled the last two years due to the low population number.
State officials are conducting a review to determine whether the white sturgeon, North America's largest freshwater fish, should be protected as an endangered species.
“The estuary is sending us multiple signals that we are extracting too much water,” Rosenfield said.
“We need to divert less water, use it more sustainably, and allow more of the water that flows from the Sierra to reach and flow through the delta,” he said. “And that would be achieved by reducing our water demand, reducing agricultural demand, and reducing municipal demand.”
Rosenfield said federal protections were long overdue. He first helped draft a petition to have the longfin smelt federally protected in 1992, when he was beginning his career as a fish biologist, but that petition was rejected.
