Chinook return in record numbers
As numbers fall across the state, Mokelumne River salmon population recovers
Although fall-run returns of Chinook salmon are low, the Mokelumne River Fish Hatchery in Clements has seen more returns than ever before, according to Peter Tira, a public information officer with the California Department of Fish and Wildlife.
“Compared to how other hatcheries are doing, Mokelumne is doing well. They’re doing a lot of innovative things down there, and that’s helping the returns. They’re probably doing the best of any hatchery in California right now,” Tira said
Run by EBMUD and the CFDW, the hatchery has already more than doubled the number of returning salmon from 8,840 in 2016, according to EBMUD media representative Nelsy Rodriguez.
“We are doing fantastic. This is the highest return on record for East Bay Municipal Utility District. As of Dec. 26, we’ve counted a total of 19,867 Chinook salmon returning,’” Rodriguez said.
By comparison, the Coleman National Fish Hatchery in Anderson, the largest in the state, fell 6 million salmon short of the 12 million they hoped to produce this season due to drought conditions in previous years as well as time spent shipping the young salmon to the ocean by truck, according to a report by the Sacramento Bee.
Rodriguez attributes Mokelumne’s success to targeted water pulses in September and November 2017, that lowered the river’s temperature, allowing returning salmon to more easily find their original spawning grounds.
The CDFW also negotiated gate closures from Monday to Friday at the Sacramento-San Joaquin Delta Cross Channel that normally supplies water to federal pumps, Rodriguez said. Had the channel remained open, she explained, the salmon would have been at greater risk of getting off course and not reaching their spawning grounds at the hatchery.
Salmon were released closer to the Golden Gate Bridge in San Francisco than in pervious years, Rodriguez said, allowing them to spend as much time in familiar waters as possible before entering the ocean. Additionally, hatcheries have been introducing more salt into the diets of growing salmon to help ease the transition from freshwater to saltwater.
These efforts, along with continued collaboration between CDFW and EBMUD, are what Rodriguez believes led to the record salmon returns this season.
“This is a testament to a great partnership with the state and forging a relationship with the Bureau of reclamation. It really is a great way to start off the new year,” Rodriguez said.
Chinook salmon from the Mokelumne River Hatchery make up approximately 18 percent of the ocean’s commercial and recreational fish harvest, according to Rodriguez. While not the majority of the harvest, she is confident that the salmon industry will benefit from the increase in returning salmon.