Longfin smelt were once abundant in the San Francisco Bay estuary, but populations have declined more than 99% from 1980s levels.
By Michael Gennaro, Courthouse News Service
The U.S. Fish and Wildlife Service officially listed the San Francisco Bay-Delta population segment of the longfin smelt as an endangered species under the Endangered Species Act Monday morning.
The longfin smelt was already listed as a threatened species under California’s Endangered Species Act, prohibiting the unpermitted possession, purchase, sale or take of the species. The service’s decision will now provide consistency between state and federal endangered species regulations, eliminating separate requirements from the state and federal levels.
The fish is 3.5 to 4.3 inches long with a translucent silver appearance on its sides and gut, while its back has an olive to iridescent pinkish hue. It lives about two to three years in bays and estuaries along the West Coast from Northern California to Alaska. The Bay-Delta longfin smelt occupies only the San Francisco Bay estuary and some areas of the Pacific Ocean.
Longfin smelt were once abundant in the San Francisco Bay estuary, but populations have declined more than 99% from 1980s levels according to Baykeeper, an Oakland-based nonprofit dedicated to defending the health of San Francisco Bay. The group attributes the fish’s decline to diversion of Central Valley tributary rivers that slash annual freshwater flow into the bay. This overuse of freshwater resources, which are mostly diverted for large-scale agricultural purposes, causes perpetual drought-like conditions for longfin smelt and other native fish in the bay.
“Like many species of fish, wildlife and their habitats, the hotter and drier climate has contributed to longfin’s decline, and the species needs our help,” said Paul Souza, U.S. Fish and Wildlife Service’s Pacific Southwest regional director, in a statement. “We are dedicated to working with others to conserve longfin smelt while recognizing the importance of wetlands in our refuges and conservation areas, the benefits of agricultural lands, and the critical water resources that sustain California’s communities.”
Fish and Wildlife’s decision follows extensive review and a court order to expedite the final determination. The primary threats to the longfin smelt include altered hydrology due to the aforementioned water management practices, nonnative species and the effects of climate change. The new rule extends federal protections to this fish.
The ruling is a response to a 2007 petition and years of legal action filed by Baykeeper and other environmental organizations, including a 2024 lawsuit filed by Baykeeper which sought to compel the service to abide by its October 2023 deadline to protect the longfin smelt.
The service proposed to list the longfin smelt as endangered in 2022 because scientific analysis showed it was in danger of extinction.
In a statement, Baykeeper science director Jon Rosenfield lauded the decision but said that more needs to be done to prevent the fish from continuing to decline.
“ESA protection for longfin smelt is decades overdue, but it’s not too late. Preventing further decline and extinction of longfin smelt will require reducing California’s diversion of fresh water from the bay’s watershed to supply unsustainable industrial agriculture, and inefficient suburban landscaping,” Rosenfield said. “Our local longfin smelt population is particularly sensitive to changes in the volume of fresh water flowing into San Francisco Bay, and its catastrophic decline is yet another sign that we take too much water from the rivers that feed the bay.”
With the longfin smelt listing, there are now six imperiled fish species native to the bay that are now protected under the federal Endangered Species Act.
RELATED COVERAGE:
Federal government declares San Francisco Bay longfin smelt “endangered”
“The United States Fish and Wildlife Service (Service) today listed the San Francisco Bay’s population of longfin smelt as endangered under the Endangered Species Act (ESA). The ruling responds to a 2007 petition and follows years of advocacy and legal action by Baykeeper and allied organizations, including a 2024 lawsuit to compel the Service to comply with required ESA deadlines. Longfin smelt were once one of the most abundant fishes in the San Francisco Bay estuary, but populations have declined more than 99% from 1980’s levels. This crash was caused by unsustainable diversion of Central Valley tributary rivers that slash annual freshwater flow into the Bay by 53% on average, and by more than 70% in the critical winter-spring period in some recent years. To thrive, longfin smelt need relatively high levels of freshwater flow into the Bay’s estuary. The extreme overuse of limited freshwater resources, which are mostly diverted to industrial agribusiness, causes perpetual drought-like conditions for longfin smelt and other native fish. … ” Continue reading this press release from the San Francisco Baykeeper.
SEE ALSO: U.S. Fish and Wildlife Service Lists Bay-Delta Longfin Smelt as Endangered, press release from the USFWS
