Into a new world

180,000 salmon get a head start on their voyage to the ocean as scientists hope to improve survival

Chinook salmon fry dipped from a raceway at Coleman National Fish Hatchery. Some 180,000 were tagged and released into the Sacramento River at Scotty's Landing, near Chico, California as part of a 6-year study to improve their survival. Credit: Jake Sisco/USFWS

Chinook salmon fry dipped from a raceway at Coleman National Fish Hatchery. Some 180,000 were tagged and released into the Sacramento River at Scotty's Landing, near Chico, California as part of a 6-year study to improve their survival. Credit: Jake Sisco/USFWS

By Jake Sisco
May 22, 2019

The raceways at Coleman National Fish Hatchery are the only home a select group of salmon fry has ever known. Feeding was regular, and there were no predators. Life was easy.

Then they were released into an alien world — one with water currents, predators and no guaranteed meals. Life, literally, became uncertain.

Marc Provencher, a fish biologist for Coleman National Fish Hatchery, prepares a fish raceway to collect 180,000 Chinook fry before transporting them to net pens at Scotty's Landing, near Chico, California. Credit: Jake Sisco/USFWS.

Marc Provencher, a fish biologist for Coleman National Fish Hatchery, prepares a fish raceway to collect 180,000 Chinook fry before transporting them to net pens at Scotty's Landing, near Chico, California. Credit: Jake Sisco/USFWS

To help prevent excess fish loss for this at-risk species, the U.S. Fish and Wildlife Service is working on a pilot project with key partners to release 180,000 marked juvenile salmon into the Sacramento River 75 miles downstream from the hatchery, at Scotty’s Landing, near Chico, California.

Coleman National Fish Hatchery's tanker truck arrives at Scotty's Landing. Credit: Jake Sisco/USFWS

Coleman National Fish Hatchery's tanker truck arrives at Scotty's Landing. Credit: Jake Sisco/USFWS

The study will test whether moving the salmon’s release point will improve their survival without causing more straying of returning adults.

A control group of an equal number started their migration earlier in the week at the standard release point, about 320 miles from the ocean, to compare their survival to the fish moved downstream.

“Two days ago we released 180,000 at Coleman. They were tagged separately with different coded wire tags and also they had acoustic tags,” said Brett Galyean, Coleman’s project leader on April 13 as he readied to release the lucky fish getting a 75-mile head start. “Based on travel time, those fish should be coming down either in a couple of hours or a couple of days right by this spot.”

The fish, moved via tanker truck to the Chico site, were released into an acclimation net pen floating in a side channel of the Sacramento River.

More than 1800,000 Chinook fry being planted into a net pen in the Sacramento River at Scotty's Landing. Credit: Jake Sisco/USFWS

More than 1800,000 Chinook fry being planted into a net pen in the Sacramento River at Scotty's Landing. Credit: Jake Sisco/USFWS

The net pen allows the fish to recover from stress and disorientation from the truck ride before being released into the river and reduces the potential that the fish will get eaten by predators upon release.

“The net pens allow them some time to acclimate," said Galyean. " They are able to right themselves.”

The two groups of fish were marked so that scientists can compare how they survive. A subset of both release groups was also fitted with tiny acoustic tags by volunteers from UC Davis that allow monitoring of their migration. Acoustic tagging will provide almost immediate data on the outmigration and survival of the juvenile salmon.

“We will be able to get survival information this year based on the acoustic tags, and then in two years we will get three-year adults returning,” said Galyean. “This will be a three-year study, so it will be a total of six years before we get all of the information back.”

Biologist Marc Provencher nets chinook fry at Coleman National Fish Hatchery. Credit: Jake Sisco/USFWS.

Biologist Marc Provencher nets chinook fry at Coleman National Fish Hatchery. Credit: Jake Sisco/USFWS

Study partners can track the salmon’s progress through the system in real time. According to Joshua Israel, the Science Division Chief in the Bureau of Reclamation’s Bay-Delta Office, the United States Geological Survey will be evaluating the release strategy’s effect on juvenile survival, and the Service’s hatchery evaluation team in Red Bluff will be analyzing information on adult return rates and straying.

“This was a collaborative project,” said Galyean. “The Service raised these fall Chinook salmon since October and we delivered them down here to Scotty’s landing. Scotty’s Landing allowed us access to this release site. The Bureau of Reclamation provided some of the acoustic tags, students from UC Davis were actually the ones who did 700 surgeries of acoustic tags. And then our partners with Nor-Cal guides and the Golden Gate Salmon Association have the net pens out there.”

And all the partners will be pulling for these juvenile salmon’s success.

Jake Sisco

Jake Sisco

About the writer...

Jake Sisco is on an internship with the U.S Fish and Wildlife Service from the U.S. Navy until mid-May. He has spent his seven years on active duty as a photojournalist, telling the Navy’s story. His enlistment ends in June.

In his spare time, he enjoys spending time outdoors with his wife and son, hunting and fishing, and he is part of a vintage baseball club playing as the rules were written in 1864.