Longfin smelt in San Francisco Bay and Delta added to Endangered Species List
The longfin smelt, a fish the length of a popsicle stick that once fed hundreds of San Francisco Bay animals including humans, was just added to a growing list of endangered species.
The federal endangered designation goes into effect Tuesday in alignment with the Endangered Species Act of 1973. San Francisco Bay's longfin smelt is a source population for estuaries all the way to Alaska.
"The main cause of their declining population is habitat loss, primarily due to long-term reductions and alterations in freshwater flow into the San Francisco Bay Estuary," said Tamara Ward, assistant field supervisor for the U.S. Fish and Wildlife Service.
These added protections mean that no one will be able to "take" longfin smelt without a permit. To take means to kill, harass, or harm the fish's ability to survive. Other Bay-Delta species listed under these protections include the Delta smelt, winter run Chinook salmon, spring run Chinook salmon, Central Valley steelhead and green sturgeon.
"This means that anyone doing a project will have to consult with the U.S. Fish and Wildlife Service to make sure that the project isn't going to harm longfin smelt," said Jon Rosenfield, senior scientist for San Francisco Baykeeper, a nonprofit environmental group focused on the health of the Bay. That includes Central Valley federal and state water projects, which sit side by side and have joint operations, he said.
Rosenfield said all six threatened and endangered species are impacted by diversions of freshwater before it reaches the Bay.
"California diverts more than 50% of the water from the Central Valley ranges that would flow into San Francisco Bay," he said.
In a 2019 fact sheet published by the Public Policy Institute of California, the statewide average water use is roughly 50% environmental, 40% agricultural, and 10% urban, although the percent of water used by each sector varies dramatically between regions. The institute report said more than 9 million acres of farmland in California are irrigated.
"It varies," said Rosenfield. "If you look in the San Joaquin, 80% of the diverted water goes to agriculture. That's the Department of Water Resource's number, 80%."
The federal designation came after a 2023 lawsuit filed by Baykeeper challenged the U.S. Fish and Wildlife Service to make its determination in the time span the law allows. The group began petitioning to list the fish as endangered back in 1992, when it first found that water diversions across several sites correlated with a decline in the species.
Now the group is concerned about the future of other species, as more water diversions are in the works by the state, such as the Sites Reservoir and the Delta Conveyance Tunnel.
The California Water Resources Control Board, the enforcement arm of the state Environmental Protection Agency, administers water rights to all the water districts in the state.
"Having a water right does not mean an agency owns the water," Rosenfield said. "It just means they have the right to divert water to the extent that you're not harming others."
The state water board is also accountable for habitat conservation under the Endangered Species Act. Beginning in 2009, the board told its water agencies that native fish and wildlife in the Bay Delta cannot survive under the current flow regime. With their water rights under threat, several agencies volunteered to fix the problem themselves.
Voluntary agreements are designs generated by certain water agencies that would result in less water diversion. They were submitted to the California Water Resources Control Board by those agencies that have seen a lot of environmental impacts from less water, such as those in the Northern Sacramento River, the Delta and the San Joaquin River. The voluntary agreements are approved by the water board, then they will function as regulations. This process began in 2018 and is ongoing.
"The governor's intent was to get all of the agencies that divert water from the Central Valley rivers, including from the Delta, to voluntarily agree to give up some water because they are required to increase flows," Rosenfield said, adding that the voluntary agreements would end up having the agencies take more water in wet years. "So that's why the water districts want to go down a voluntary route where they give up less to protect the Bay in return for insulation from regulation from the water board."
"I'm not saying that increasing flows would be a panacea for the six endangered fish species," he said. "I'm saying without increased flows, there is no solution. For those, they will continue to decline."