Monday July 14, 2025
SF Gate —
Wildlife officials say the population of a native California species is continuing to rapidly plummet.
Dinosaur-like in appearance and existing on Earth for the past 200 million years, white sturgeon are the largest freshwater fish in North America. They can be found all the way from Alaska to Mexico, primarily residing in large waterways like the Sacramento-San Joaquin River Delta and the San Francisco Bay estuary. Historically, the ancient fish could grow larger than 20 feet in length — the size of a standard shipping container — and live for more than 100 years.
ies conducted by fisheries biologists from the California Department of Fish and Wildlife have revealed there are just 6,500 white sturgeon between 40 and 60 inches long left in the state — “down sharply” from a previous estimate of 30,000 fish in that size range recorded between 2016 and 2021.
A Wednesday news release from the agency cited “mortality from harmful algal blooms,” which killed over 850 of the fish in 2022 alone, and “poaching, past sport fishing harvest and poor river and Delta conditions” as possible reasons for the downward trend. According to a report from the agency, their numbers have been in decline for at least three decades; the state closed fishing for them under emergency regulations and considered listing them as threatened under the Endangered Species Act.
“Changes to the Bay-Delta system and changes to our climate are happening too quickly for them,” UC Davis fish biologist Andrea Schreier told Bay Nature last July.
CDFW officials have been monitoring the white sturgeon population since the 1950s and initiated the new survey program last year to better monitor their numbers across different size and age ranges and determine conservation efforts. In the spring, lines with multiple baited hooks are used to capture sturgeon that are subsequently measured, tagged and released. Later in the fall, scientists compare the number of tagged and recaptured fish to the number of untagged fish to estimate population size. The study design, based on surveys conducted in Washington and Oregon, “is the most robust and comprehensive white sturgeon population monitoring survey ever conducted in California,” the agency said.
Catch-and-release fishing of white sturgeon remains banned through Oct. 1 as the California Fish and Game Commission decides whether to continue limited seasonal harvest of the prehistoric species at its next meeting on Aug. 13.