Record salmon run returns to Mokelumne River, while low numbers return to Upper Sacramento

The Mokelumne River is hosting a record number of fall-run Chinook salmon this year, while the Upper Sacramento River is seeing a shockingly low return of fish.  

A total of 29,912 fall-run Chinook salmon have moved past the Woodbridge Diversion Dam on the Mokelumne River as of November 13, 2024, according to Michelle Workman, the East Bay Municipal Utility District’s Fisheries and Wildlife Manager. This will be an all-time record for fall Chinook spawning escapement on the river, a tributary of the San Joaquin River. 

“Last year the total run size was 28,865, while the total run last year on the same date was 20,859,” said Workman.

The Mokelumne River Fish Hatchery has taken 3.8 million eggs at the facility so far.

The 95-mile long river, rising in the rugged central Sierra Nevada, supplies water to EBMUD customers.

Workman attributed the big numbers of fish returning from the ocean this year to EBMUD pulsing 53,000 acre feet of water from Camanche Reservoir to the lower Mokelumne River in October to attract salmon, along with the continued closure of ocean and river salmon fisheries due to the collapse of Sacramento and Klamath River salmon populations. 

A new record for the number of steelhead returning to the Mokelumne River was set in February of this year. A total of 1,749 steelhead, including 968 adults and 781 fish under 18 inches, returned to the system.

The previous record for total steelhead was in 2018 when the hatchery reported 530 adults and 638 juveniles, a total of 1168 fish. However, there was another year when the total number of adults was over 700 fish. 

On the other hand, the salmon run on the Upper Sacramento River is alarmingly low this year. The Coleman National Fish Hatchery, located on Battle Creek, a Sacramento tributary, supplies the majority of fish for the upper section of river below Redding. 

“As a result of our low run of fall Chinook salmon this year, we have partnered with California Department of Fish and Wildlife to transfer eggs to Coleman from state hatcheries in the Central Valley,” the Coleman National Fish Hatchery reported on their Facebook Page. “Our normal production is 12 million juvenile fall Chinook salmon; this year we have collected approximately 5.4 million eggs at the hatchery.”

The Mokelumne Hatchery will be supporting Coleman by supplying eggs to Coleman at their request. “One million eggs have already been taken for Coleman fish, with more to come later in the month,” said Workman.

Regarding the record salmon run on the Mokelumne this year, Scott Artis, Executive Director of the Golden State Salmon Association (GSSA), stated, “This steps back to what we saw last year as well: that when we actually give fish the right water conditions or truck them past the Delta pumps, hot water and low flows, and give them a chance to survive, we see record returns despite all of the layers of bad salmon policy."

“Mokelumne River salmon are escaping all of Newsom’s bad water policies and are producing a record number of fish. That should tell us something,” he noted.

“Whether the administration is Democratic or Republican, we need to make sure that at the end of the day we’re not killing tens of thousand of salmon jobs, entire coastal towns and cultures that rely on salmon,” Artis concluded. 

The numbers of fall Chinook salmon returning to the Feather River Fish Hatchery in Oroville and Nimbus Fish Hatchery on the American River in Rancho Cordova — and the number of eggs both facilities have taken — were not available yet.

Recreational and commercial salmon fishing in California waters and recreational salmon fishing on the state’s rivers has been closed for two years, due to the collapse of Sacramento River and Klamath River fall-run Chinook populations.

Since the Mokelumne River is a tributary of the San Joaquin River, the number of salmon returning to the river is not figured into the Sacramento River index that the ocean abundance estimates are based upon. These estimates are used by the Pacific Fishery Management Council (PFMC) to craft the salmon seasons each year.