FRIANT, Calif. — Donald Portz performs surgery in a parking lot at Lost Lake near Friant Dam. Within minutes, his patients are awake and taking the swim of their lives in the San Joaquin River.
Portz is a federal fisheries biologist, one of many scientists and engineers working on an epic project — reviving California’s second-longest river and rebuilding the nation’s southern-most salmon runs.
Sometimes, that means standing next to a pickup truck near the river and surgically inserting tiny transmitters, or tags, into resilient juvenile salmon.
“We might lose one fish in a thousand,” Portz said. “With these tags, we will be able to track these fish all their lives.”
Following these 3-inch fish is a priority in the fourth year of the restoration program. It’s scientifically important. And it is progress in a program that has had its share of hurdles, such as construction delays and damaged downstream farmland.
Scientists need to understand how these tiny fish will pass through the river toward the Pacific Ocean. Are there blockages? Will many disappear in stretches where there are predator fish?
The San Joaquin revival is supposed to move beyond this experimentation to the full restoration in the next several years, so these kinds of questions need answers.
It’s a time of learning and adjusting for both scientists and the San Joaquin Valley farm community now sharing the river with nature.
The river dried up for about 60 miles after Friant Dam was built in the late 1940s, and chinook salmon runs died. East Valley farmers, who need the river for irrigation, fought a losing court battle for nearly two decades before reluctantly signing a 2006 restoration agreement.
Their worry has always been about water losses, especially in dry times. After a second dry winter in a row, east-side farmers will have to live with about 55 percent of their high-priority water from Millerton Lake. What would that water allotment look like without the restoration taking a bite?
“It probably would have been about 70 percent,” said Steve Ottemoeller, spokesman for Friant Water Authority, representing 15,000 east-side farmers.
Farmers on the west side of the Valley are worried, too. The revived river will run again through the west side. As the river periodically refills with experimental flows in previously dry stretches, the water has seeped beneath farm fields, damaging crops, provokes an outcry from west-siders.
The Bureau of Reclamation is fine-tuning its experimental water releases to protect the west-side land.
The experimental releases from Friant Dam will shrink this year because of the dry winter. The bureau estimates about 170,000 acre-feet of water will be devoted to the experimental flow this year, down from about 185,000 last year.
The bureau recaptures some of the experimental releases downstream and makes the water available to east-side farmers. Last year, farmers got 103,000 acre-feet of recaptured water. This year, the bureau intends to recapture about 72,000 acre-feet.
For fisheries biologists, the dry year should not affect the tracking of juvenile salmon for 62 river miles between Friant Dam and the Mendota Pool, near the city of Mendota.
The young fish are surgically outfitted with a transmitter less than half an inch long. Scientists are interested in finding out how quickly juvenile salmon move through the river and how many survive the trip to Mendota Pool.
It’s likely most of the salmon will end their journey at the pool. But some might get through Mendota Dam, an old structure that allows water to pass over the top when the pool fills up.
The fish transmitters, devised decades ago, are ingeniously low tech. Instead of a battery, they have a copper coil, which triggers sensor stations in the water as the fish swim past. The stations amount to antenna arrays that cause the transmitter in the fish to send a radio message.
“We have six of these locations going down the river,” said fisheries biologist Portz. “When they are activated, we get a tag number and a time and date stamp. We know exactly which fish is passing through.”
Because there is no battery, the transmitter remains useful throughout the life of the fish. Some of these transmitters have worked in fish for many years.
The transmitters cost $2.60 apiece when the government buys them in bulk. Portz compares them with a small, battery-powered acoustic tag that transmits sounds and might only last days in these salmon, Portz said. The acoustic tag might cost $340, he said.
It is far more affordable to put the cheaper tag in thousands of juvenile salmon in the San Joaquin.
The young fish are the offspring of chinook salmon captured downstream last fall as they tried to migrate up the river. But salmon from the Feather River Hatchery in Northern California also are tagged and released in the San Joaquin.
The fish soon “will provide invaluable information to support the reintroduction of salmon to a restored San Joaquin River,” said Monty Schmitt, senior scientist for the Natural Resources Defense Council. The council represented environmentalists and conservationists in the long-running restoration lawsuit.
Back at the San Joaquin River, young fish with new transmitters are in post-op — a bucket of water where they quickly come out of the mild anesthesia.
Wearing waders, Portz and his colleagues take the bucket into the river and gently release the fish into the cold water, watching every move. The salmon hang around for a few minutes, then start moving downstream toward the first sensor station.
“Salmon are really strong,” Portz says. “They’re amazing fish.”