Hatchery International

Features Regulations Restocking
California’s prized steelhead in murky waters

May 28, 2024  By Julia Hollister

“The primary impacts are loss of historic habitat due to non-passible structures/dams, limited available habitat that is degraded and has poor water conditions, large scale impacts from climate change in both the inland and ocean environment.” Photo: John R. McMillan NOAA/NWFSC

Editor’s note: The southern California steelhead was officially added to the Endangered Species Act on April 18, one month after this article was printed for the May/June 2024 issue

There is no doubt about the numbers: steelhead in California are in big trouble.

“Some stocks, or populations, of steelhead are listed under the Endangered Species Act, which provides federal protection to threatened and endangered species,” said Michael Milstein, Public Affairs Officer, NOAA Fisheries, U.S. Department of Commerce. “The Southern California Distinct Population Segment of steelhead is the only West Coast population of steelhead that are listed as endangered, while several others including California Central Valley, Northern California and Central California Coast steelhead are listed as threatened.”

Species can be listed as “endangered” if they are in danger of extinction throughout all or a significant portion of their range. Threatened species are likely to become endangered in the foreseeable future throughout all or a significant portion of their range. 


Both receive federal protection under the Endangered Species Act, although there are some limited differences.

“Milstein said in most cases, steelhead eggs are collected from adult broodstock that return annually to the hatchery. The eggs are hatched and reared within a hatchery facility for approximately one year. Steelhead juveniles are released as yearlings, typically between the months of January-April

There are factors affecting steelhead survival.


Predators are one factor affecting steelhead survival and recovery, but not the only factor. Most steelhead hatchery programs in California were established to help offset or mitigate the loss of spawning and rearing habitat behind high-head dams. 

The species preying on steelhead range from birds such as gulls and terns to other, often invasive species of fish, as well as marine mammals such as seals and sea lions. While steelhead have always faced predators, changes in their habitat and other factors have made them more vulnerable in some situations. 

“If it is the ladder, predators (birds, sea lions, otters, piscivorous fish) can have some localized impacts to released fish; but each hatchery has developed release strategies that help to minimize potential impacts,” said Jonathan Nelson, environmental program manager at Anadromous Fishes Conservation and Management Program at the California Department of Fish and Wildlife (CDFW). 

“This includes releases at dusk/evening, releasing in different locations within the river for each release, releasing fish at larger size to improve survival to the ocean.”

For instance, the loss of riparian and floodplain habitat has reduced opportunities for young steelhead to hide from predators during their migration. In some cases the fish funnel together at dams and predators can take advantage of that. NOAA Fisheries and their partners have invested in restoring habitat and other measures to reduce the toll that predators take over the course of the steelhead life cycle.

“I want to stress that the main purpose of these hatcheries is to support fishing and harvest opportunities,” said Nelson. “The fish from hatcheries have their adipose fin clipped so fishermen can tell that is a fish that can be harvested. However, since they are similar to the original stock, they are considered part of the listed species.”

Rowdy Creek Hatchery (a small tribal led program on the Smith River that raises non-listed Klamath Mountains Province steelhead.) Annual production numbers are variable, based on adult returns
Operator: Tolowa Dee-ni Tribe
Location: Rowdy Creek – Tributary to the Smith River
Annual SH smolt release target: 80,000

Harnessing hatcheries

Hatchery fish primarily support fishing, which by selectively removing the hatchery fish allows the naturally spawning fish in the rivers to continue to survive and hopefully recover.

The exception is the Nimbus hatchery. Those steelhead are from a coastal stock and do not resemble the native stocks. For a long time, it was not included in the endangered species list.

Usually a hatchery has one of two purposes – either it produces fish to support fisheries, or it is intended for conservation purposes to help restore a species. These hatcheries are all supporting fisheries. 

Nelson explains the endangered act and the threats to California’s steelhead.

“For clarification, there is a Federal Endangered Species Act (ESA) Designation process that is overseen by National Marine Fisheries Service (NMFS) for salmon and steelhead,” he said. 

“Separately the State of California has the ability to list species under the California Endangered Species Act (CESA).  In California, there are six Distinct Population Segments for steelhead populations designated by NMFS. NMFS has listed the Southern Calif. Steelhead DPS as ESA Endangered.”

California currently has one CESA Endangered steelhead listing for the Northern California Summer Steelhead population.

The Southern steelhead geographic range extends from the Santa Maria River in Santa Barbara County south to the U.S.-Mexico Border. There is no recreation fisheries allowed for steelhead in these ranges and there are no hatcheries that produce steelhead in this range.

“California has listed the Northern CA Summer Steelhead population as CESA Endangered,” he said. “There are several specific waters within the Northern California geographic range that include endangered summer steelhead populations. All of the critical areas that have these populations are closed to fishing.” 

The Mad River is the only river in this range that has a hatchery producing steelhead. The hatchery does not produce summer steelhead and there is minimal contact with summer steelhead when hatchery operations are collecting winter steelhead adults.

“There are numerous reasons/information why these specific populations are listed,” Nelson said. “The primary impacts are loss of historic habitat due to non-passible structures/dams, limited available habitat that is degraded and has poor water conditions, large scale impacts from climate change in both the inland and ocean environment (fire, flood, slides, drought, ocean warming) and reduced water availability from human water usage.”

CDFW recently completed a status review for the Southern Calif. steelhead trout population to determine if a CESA listing is warranted. The review will be presented to the Cali. Fish and Game Commission (FGC) in April where they will decide if the species will be listed as Endangered under CESA or not. If approved for listing, this would be the second Endangered CESA Listed steelhead population in California.

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