Wednesday August 27, 2025
Sierra Daily News —
The Department of Water Resources announced Monday its fish monitoring station at the Feather River Fish Hatchery, installed July 2023 about 6.5 miles from the hatchery, has helped reduce staff hours spent conducting carcass surveys by three-quarters — and, best of all, the counts of spring-run salmon are up.
The monitoring station is said to be a valuable tool for scientists counting Chinook salmon and steelhead trout populations in the Feather River; it uses an underwater camera to track arrival timing, number, species and origin of returning fish — whether natural or hatchery raised, according to the release.
“For years DWR and its partners have estimated fish populations by tracking how may fish entered the (hatchery) and through carcass surveys in the river,” stated Byron Mache, environmental scientist with DWR. “This monitoring tool provides key data to California fisheries and water managers and significantly reduces staff time counting fish on the river.”
About 17,700 spring-run salmon were estimated in the Feather River this spring, which DWR said was the “best return since 2013.”
In 2024, DWR tracked 7,000 spring-run salmon and 40,000 fall-run salmon.
Before DWR installed monitoring station, it sent at least four boats per day with staff working multiple weeks to estimate Chinook salmon populations by conducting carcass surveys, the release said.
Now, the department uses a camera at the station to automatically count fish traveling up the river with motion detectors — a method that can better differentiate counts between fall-run and spring-run salmon, according to the release.
Before the construction of the Oroville Dam in the 1960s, spring-run Chinook salmon would access the upper Feather River to take advantage of higher river flows, according to the release. But now, spring-run Chinook salmon spawn at a similar time as fall-run Chinook salmon because of the dam’s inaccessibility.
“Fish migrating from the Delta and Sacramento River could travel 170 miles or more to the upper reaches of the Feather River,” the release said. “With Oroville Dam preventing spring-run Chinook salmon from migrating further up the Feather River, they now spawn in the valley at a similar time as fall-run Chinook salmon, making it difficult to differentiate between the two using traditional survey methods.”
This method, according to the release, is said to improve counts of these two runs of salmon while significantly reducing staff time on the river by about 75%.
Since being installed, the station has recorded more than 10 different fish species in the Feather River, including Chinook salmon, steelhead, Sacramento pikeminnow, hardhead, pink salmon, chum salmon, American shad and striped bass.