California’s most productive salmon hatchery is millions of fish short
ANDERSON — California’s most productive salmon hatchery has 6 million fewer fish this year, another sign the state’s drought woes linger despite last winter’s record rainfall.
The federal Coleman National Fish Hatchery tries to produce about 12 million fall-run Chinook salmon for release each spring into Battle Creek, a Sacramento River tributary south of Redding. This spring, the Coleman hatchery will only have half as many young salmon to release.
The reason harkens back to the abysmal river conditions in the heart of California’s historic five-year drought — and the choices fishery managers made those years to move the baby Chinook by tanker truck out to sea in a frantic effort to save the commercially important fish.
They knew at the time trucking the fish would lead to fewer fish coming back to Coleman this year to spawn.
“Everybody kind of acknowledged and understood at the time the consequences,” said John McManus, executive director of the Golden Gate Salmon Association, a fishing advocacy group.
Chinook live two or three years in the Pacific Ocean before adult fish head back upriver to lay their eggs and die, starting the cycle anew. Fish hatched in California’s five-year drought that ended officially in the spring are returning to Central Valley rivers this year.
Almost all of the Central Valley’s fall-run Chinook are hatched from eggs and sperm that biologists harvest from adults that return to hatcheries below the dams blocking the fish from their traditional spawning habitat.
Fall-run adult fish — raised at five hatcheries across the Central Valley — provide the bulk of the fish caught in the commercial and recreational fishing industry. McManus and other fishing advocates say fall-run Chinook support $1.4 billion in annual economic activity in California and about 23,000 fishing related jobs while providing locally caught fish for Californians’ dinner tables.
Because of the hatcheries, fall-run Chinook (and the smaller late fall-run) are the only Central Valley salmon runs healthy enough to avoid protections under the U.S. Endangered Species Act. The spring run is listed as threatened. The winter-run is critically endangered. The runs are named for the season when the majority of the adult fish enter freshwater.
The drought played havoc on all the runs, which need cold water to thrive. Returns of spring- and winter-run Chinook born during the drought are among the lowest on record.
The dry winters of 2014 and 2015 left the Central Valley’s rivers languid, clear and warm for long stretches — terrible conditions for a young salmon, and particularly perilous for fish that hatch far upriver because they have farther to swim.
Salmon are a cold-water fish, and juveniles are more likely to survive their trip to the sea when they have plenty of food and can avoid predators in rivers cloudy and swift from nutrient-rich stormwater runoff.
Coleman is the farthest Sacramento Valley hatchery from the Pacific. Young fish — called smolts — hatched at Coleman have to swim 280 miles of river to reach salt water. Normally, that journey helps them navigate back to their hatchery years later.
In the dry spring of 2014, Coleman’s managers decided that the Sacramento River was so warm that almost all Coleman fish would die if they were released into Battle Creek — a move that would potentially kill the salmon fishing industry a couple of years later when the fish grew into adults.
So that spring, all 12 million Coleman fish were sucked into dozens of tanker trucks, driven to the Sacramento-San Joaquin Delta and dumped into floating pens near Rio Vista to acclimate them for later release.
Coleman fish weren’t the only fish trucked. Millions more juvenile fall-run fish raised at the Central Valley’s four other salmon hatcheries were also transported. The process repeated the following year. The trucking program likely saved this year’s fishing season.
Biologists estimated this spring there were 230,700 in the Pacific Ocean waiting to pass under the Golden Gate Bridge and head upriver into the Central Valley. Though 70,000 fewer than last year, there were enough adult fish to allow for a commercial fishing season off a portion of California’s coast.