By the time Estuary debuted in 1993, the Central Valley’s once abundant runs of Chinook salmon had been severely depleted by dams, diversions, pollutants and predation by non-native fish. Sacramento River winter-run fish were federally listed as endangered in January 1994; the Central Valley spring run was listed as threatened in 1999 and the fall run is identified as a species of concern. Protecting and rebuilding these populations has been a lodestar for many, if not most, of the efforts to restore the Bay and Delta, beginning with 1992’s Central Valley Project Improvement Act. Over the decades, armies of scientists, engineers and water managers have sought to better understand and mitigate the threats to this iconic fish, while lawyers, activists and politicians have battled over their habitat and freshwater flow needs. To read about salmon in the context of other estuarine fishes with different life stories see Estuary’s special March 2022 Fish Tales issue.
When a team of fish biologists was tasked with restoring spring-run Chinook salmon in the San Joaquin River in 2006, none of them quite knew where to begin. The thirsty farms that crowd the river on both sides had taken almost all the water out of it most years since the mid-1900s, leaving a nearly […]
The days when salmon and steelhead teemed in California’s coastal watersheds faded away last century. Today, many populations of the fish are gone or dwindling, the river systems where they spawn drained by diversions or too warm for native fish to survive. Warming trends and drought are squeezing water resources tighter. Nearly all efforts to […]
After two critically dry years that coincided with Trump-era rollbacks to environmental protections, some iconic Delta fish are closer than ever to the point of no return. Last fall, for the second year in a row, the fall midwater trawl found zero wild Delta smelt, while a coalition of environmentalists and fishermen is asking a […]
In 2012 a team of salmon researchers tried a wild idea: putting pinky-sized Chinook on a rice field in the Yolo Bypass, a vast engineered floodplain designed to protect the city of Sacramento from inundation. The team found that rearing fish on farms works better than they had ever dreamed. Salmon in this managed floodplain […]
It’s a cold morning in early February, and Chris Vallee of the U.S. Geological Survey is motoring upriver along Steamboat Slough. His two-man crew is hunched in the bow with backs to the wind, wrapped to the ears in water-resistant jackets above warm layers. Vallee pilots the vessel in relative comfort behind the shelter of […]
By Robin Meadows “The dream is to reestablish a natural run of salmon in Putah Creek,” says UC Davis professor emeritus Peter Moyle. In 1972 Putah creek was a trickle of water between heavy machinery mining gravel for the campus roads. Moyle and others urged the university to cease mining and by the end of […]
Salmon once flourished in California despite huge swings in climate that were far more extreme than those today. But then people re-engineered the state’s waterways to meet their own needs. “Complexity is what salmon thrive on, and we’ve been making their habitat simpler and simpler,” says biologist Bruce Herbold. “We haven’t been playing to their strengths.”
Two decades after the South Bay’s main water supplier agreed to restore aquatic habitat in the streams that flow from its reservoirs, fish in the region remain in dire straits, and local river advocates say it’s the Santa Clara Valley Water District’s fault. The agency, which serves the taps and toilets of 1.9 million Santa […]
Ted Frink recalls watching Jacques Cousteau’s television specials when he was growing up in coastal Orange County. “I envisioned myself as Cousteau,” says Frink, a fisheries biologist with the California Department of Water Resources (DWR) now approaching retirement. “My folks encouraged my interest in science. I knew I could be a biologist.” That early inspiration […]
On the morning of November 8, 2018, Allen Harthorn, a farmer who lives about two miles from the town of Paradise, watched a dark cloud of smoke forming in the east and began to worry about the safety of his and his neighbors’ homes. He also began to worry about some other residents of the […]
A decade of research by David Baldwin of NOAA’s North west Fisheries Science Center and other biologists has shown that very low levels of dissolved copper interfere with a salmon’s ability to detect smells. This can be a matter of life or death: salmon rely on their olfac tory sense to avoid predators…
Walk back through time with this selection of early stories. Estuary News launched in 1993, and for the first few decades focused on key policy and environmental issues for San Francisco Bay and Delta. For many years it published bimonthly as an eight-page newsletter before it evolved into a magazine and added a digital platform […]