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For hundreds of years fall Chinook salmon in the Central Valley of California have been abundant and thrived in the rivers and tributaries flowing through the great valley.
Little by little as rivers and streams were modified by dams and channels beginning in the early 1900s, salmon populations began declining. In 1942, Congress recognized that hatcheries were needed to help support these fish and established Coleman National Fish Hatchery to mitigate the loss of salmon naturally returning to historic spawning areas.
Each year, Coleman needs to collect 3,500 pairs of fall Chinook salmon during the months of October and November to meet its annual production goal of 12 million juvenile fall Chinook salmon. Typically, plenty of salmon return to the hatchery via Battle Creek, however, 2024 was different story, with 1,100 females returning in the fall. As a result, the hatchery collected roughly only 5.5 million eggs.
What made 2024 different?
The low numbers of returning adults are likely due to the drought conditions in the spring of 2022. To fully understand, one must know some basic biology about salmon that are spawned, hatched and raised at Coleman. Most fish returning to the hatchery are three years old. Adult fish are spawned at the hatchery in the fall, juveniles are released into Battle Creek in the spring, and then they return to spawn, in the fall, three years after they were born.
Eggs collected in the fall of 2021 were raised to juvenile fish and then released in the spring of 2022. At the same time, California was in a third consecutive year of drought lasting from 2020 to winter 2022. The juvenile fish released during the drought faced harsh release conditions due to low flows in the Sacramento River. During low flow conditions, predators both in and above the water can easily spot the small fish as they move downstream, and warm waters can negatively impact fish survival. Fish released in the spring of 2022 faced all of these conditions; storms never materialized and flows in the river remained low and the water relatively clear, leaving less places for the fish to hide.
What now?
To make up the deficit in returning salmon, the U.S. Fish and Wildlife Service requested eight to 10 million fall Chinook salmon eggs from the California Department of Fish and Wildlife hatcheries. Beginning in early-November, eggs were transferred to Coleman from hatcheries operated by the state wildlife agency including: Mokelumne River hatchery, operated in partnership with East Bay Municipal Utility District, and the Feather and Nimbus state fish hatcheries, operated with California Department of Water Resources.
"This egg transfer is a great example of how agencies can work together, across jurisdictions to do what is best for all," said Paul Souza, U.S. Fish and Wildlife Service Pacific Southwest Regional Director. “Our partnership with the state will allow Coleman National Fish Hatchery to take full advantage of the facility’s rearing capacity and we are grateful to our partners for their commitment to collaborative and creative solutions to support California salmon. Our efforts this year will improve the likelihood of higher fall-run Chinook salmon returns in 2027, benefiting communities and fishing opportunities."
This "win-win" situation occurs, when the state hatcheries exceed their production needs and look for collaborative and creative ways to benefit salmon by transferring their excess eggs - in this case to the Coleman National Fish Hatchery. The U.S. Fish and Wildlife Service including the Coleman National Fish Hatchery, the California Department of Fish & Wildlife, the National Marine Fisheries Service, fishing organizations and water users continue to work together and look for ways to develop creative and innovative strategies to address salmon declines.
“For years, the mainstem Sacramento River has been the key driver of Central Valley Chinook salmon stocks,” said Chuck Bonham, California Department of Fish and Wildlife Director. To see this part of the run in such dire straits is incredibly concerning. Thanks to the partnership among the California Department of Fish and Wildlife, East Bay Municipal Utility District, Department of Water Resources and our federal partners at the U.S. Fish and Wildlife Service, we are taking bold, collaborative steps to help reestablish this important run.”
"We are encouraged by the recent efforts of Coleman National Fish Hatchery to improve salmon runs to the upper Sacramento River. Returns to the hatchery, as well as natural spawning areas, have been declining for many years. Since our commercial fleets rely on strong production from both hatcheries and natural areas, we are committed to working with Coleman managers to develop innovative hatchery practices,” said George Bradshaw, president of Pacific Coast Federation of Fishermen’s Associations. “Egg transfers from nearby state hatcheries are the most immediate way to increase the overall salmon population, decrease stray rates, and minimize adverse impacts on other fish stocks. We are very appreciative of efforts from USFW and CDFW to make these transfers happen."
