Into the darkness: Imperiled spring-run Chinook salmon released into upper San Joaquin River

U.S. Fish and Wildlife Service fisheries biologists and partners get preparations underway at the Eastside Bypass on the San Joaquin River, where almost 90,000 spring-run Chinook salmon would be released later that evening. "We are now able to reintroduce threatened spring-run Chinook salmon back into the upper San Joaquin River only because of the unprecedented commitment and cooperation among state and federal agencies, landowners and NGO's," said  Maria Rea, of  NOAA Fisheries' Central Valley Office. Credit: Steve Martarano/USFWS

By Steve Martarano and Josh Newcom
March 21, 2017

When almost 90,000 3-inch spring-run Chinook salmon shot into the darkness of the Eastside Bypass of the San Joaquin River the night of March 6, they didn’t get there alone. It took a strong, collaborative effort by numerous state, federal, university and private entities, working for months under the umbrella of the San Joaquin River Restoration Program (SJRRP) to ensure that the imperiled salmon species continued to thrive for future generations.

That collaboration was impressive.

More than half of the fish for this year’s release came from California’s Interim Salmon Conservation and Research Facility. The release marked only the second year juveniles produced solely on the San Joaquin River have been released into it. Credit: Steve Martarano/USFWS

While California's Department of Fish and Wildlife (CDFW) is the state natural resource partner in the program and conducted the rearing, tagging, transport and release of the fish, numerous entities laid groundwork for the release. The U.S. Fish and Wildlife Service is the lead agency responsible for the reintroduction of spring-run to the San Joaquin River. The National Oceanic and Atmospheric Administration (NOAA) is the permitting lead and established a rule under the Endangered Species Act that allowed for the reintroduction of spring-run, outside the species’ current range.

And, the U.S. Bureau of Reclamation coordinated with private landowners and the Lower San Joaquin Levee District to obtain an accessible fish release location to provide the salmon the best opportunity to migrate downstream.

By the time the late-night releases took place off Washington Road near the city of Merced, approximately 15 participants were on-hand overseeing and monitoring water quality and fish conditions, helping send the juvenile spring-run Chinooks on their trip down the San Joaquin River and out under the Golden Gate Bridge to the Pacific Ocean.

Biologists from the California Department of Fish and Wildlife prepare to pump 90,000 juvenile spring run Chinook salmon into the upper San Joaquiin River, March 6, 2017. Credit: Steve Martarano/USFWS

"This project is simply too big and too important for any one group or organization to complete on their own,” said Maria Rea, office chief for NOAA Fisheries' Central Valley Office. "We are now able to reintroduce threatened spring-run Chinook salmon back into the upper San Joaquin River only because of the unprecedented commitment and cooperation among state and federal agencies, landowners and non-governmental organizations."

Traditionally, spring-run Chinook salmon were the most abundant run of Chinook salmon in California’s Central Valley.

But the construction of dams and water diversions, along with continuous degradation of spawning and rearing habitat, ongoing fishing pressure, and an increase in predator populations among other threats, led to the near extinction of spring-run in all rivers in the Central Valley. In 1999, spring-run were listed as threatened under the Endangered Species Act.

Melanie Cardillo (left) and Alex Xiong, scientific aides from the California Department of Fish and Wildlife, empty the holding tank at the Interim Salmon Conservation and Research Facility, near Fresno, Calif. Credit: Steve Martarano/USFWS

The majority of the fish for this year’s release (51,044 fish) came from CDFW’s interim Salmon Conservation and Research Facility and marked only the second year of releasing juveniles produced solely on the San Joaquin River. The remainder of the released salmon (38,106 fish) were raised at the Satellite Incubation and Rearing Facility from eggs translocated from the Feather River Fish Hatchery in Oroville.

On the day of the release, CDFW workers at the interim facility near Friant Dam spent several hours scooping fish from holding tanks into two fish transport trucks before taking them over to the river’s Eastside Bypass release location.

Roughly 350 of the fish released had state-of-the-art transmitters inserted that allow them to be tracked by scientists as they head to the Pacific Ocean. Credit: Eric Chapman/UC Davis

The fish were released in total darkness just before 9 p.m. Though the actual release took just a few minutes, the fish were held in the transport tanks beforehand for about four hours in river water to acclimate. The releases occurred well after sunset to thwart predators.

As a result, the yearly release in the San Joaquin River has taken on added significance and the March 6 effort provided the best conditions yet, said Don Portz, lead fisheries biologist for the San Joaquin River Restoration Program.

"We feel this will be our greatest opportunity for adult spring-run returns in the last four years of juvenile releases,” Portz said. “With more than 89,000 salmon released under flood flows, we now have a fully connected river, optimum temperatures, and turbid conditions to help conceal the fish from predators on their outmigration to the ocean."

Spring-run Chinook salmon at the Interim Salmon Conservation and Research Facility at Friant Dam north of Fresno, Calif. It took just a few minutes for each truck to release all 90,000 fish later that evening. Credit: Steve Martarano/USFWS

While this was the fourth year in a row spring-run Chinook salmon were released as part of the program, this is the first time the fish will be monitored with tracking technology as they move downriver. The process to insert the transmitters – known as juvenile salmon acoustic telemetry system, or JSATS – resembles a miniature operating room.

The study was made possible through a grant from the Delta Science Program and the 15 millimeter-long transmitters are surgically implanted through an incision into the abdominal cavity of the anesthetized juvenile fish. The incision is then closed by a single suture. Powered by small hearing aid-type batteries, the tags are expected to emit a signal for up to 60 days.

The sunset view from Eastside Bypass of the San Joaquin River on March 6, where the fish were later released to begin their journey to the Pacific Ocean. Credit: Steve Martarano/USFWS

Following release, the fish will be tracked using a series of receivers placed in the river at intervals from the release site and out to the ocean.

“Fish can be detected by the receivers from up to 300 yards away,” said Eric Chapman, one of the lead researchers with the UC Davis program. Data from the tracking will be recorded, he said, and will provide scientists with a greater understanding of migratory routes, travel duration, survival rates, and other information to better understand fish migration within the San Joaquin River system. If all goes well, the juveniles will feed and grow for the next two to five years before beginning their journey back up the river to spawn and produce the next generation of offspring.

The re-establishment of a self-sustaining spring-run Chinook salmon population to the San Joaquin River is dependent upon a progressive introduction process that involves both natural and hatchery supplemented production, said Lori Smith, fish biologist in the Service's’ Lodi Fish and Wildlife Office.

“The expectation of our hatchery production release is that a percentage of these fish will successfully complete their lifecycle, return to the San Joaquin River and contribute naturally to the spring-run Chinook salmon population and thus to the SJRRP’s long-term population goals,” Smith said.

 

Steve Martarano is the public affairs officer for the San Francisco Bay-Delta Fish and Wildlife Office located in Sacramento, Calif.  Josh Newcom, U.S. Bureau of Reclamation, is the public affairs officer for the San Joaquin River Restoration Program.

 

NOTE: The San Joaquin River Restoration Program is the result of a 2006 legal settlement following an 18-year lawsuit. The program goals are to restore and maintain naturally reproducing and self-sustaining populations of salmon and other fish in “good condition” in the mainstem of the San Joaquin River below Friant Dam to the confluence of the Merced River while reducing or avoiding adverse water supply impacts to all Friant Division long-term contractors that may result from restoration flows provided for in the Settlement.

For more information, visit the program website at www.restoresjr.net.