Article from Stockton Record.
http://www.recordnet.com/apps/pbcs.dll/article?AID=/20140418/A_NEWS/404180322
By Dana M. Nichols
April 18, 2014 12:00 AM
STOCKTON – For the first time in more than 60 years, spring run salmon fingerlings are gliding through the waters of the San Joaquin River.
The release of 54,000 chinook salmon Thursday and today is part of one of the largest river restoration efforts in U.S. history, and scientists say they are optimistic that some of the salmon will survive to return as adults in three years.
“It is a good day for fish despite being in a drought year,” said Monty Schmitt, senior scientist with the Natural Resources Defense Council.
The council was one of the parties to a 2006 legal settlement that launched an effort to restore salmon and, at least in some years, water flows to the lower San Joaquin River.
Friant Dam, completed in 1942, allowed for the diversion of the river’s waters to irrigate farms. By the 1950s, both the spring and fall salmon runs were gone, and miles of river bed had gone completely dry below the dam.
The juvenile salmon being released here were raised in the Feather River Hatchery.
Normally, fish that go downstream to the ocean eventually try to return to the river where the were hatched. But scientists say they’ve learned how to convince the juveniles to be loyal to a different home river.
“You can move fish from one system to another and they will imprint on the new system given enough time in that water,” Schmitt said.
“They were moved down last week on Tuesday and have been held in net pens right below Friant dam and are being allowed to imprint on the San Joaquin River.”
Since there’s dry river bed between those young fish and the Pacific ocean, they are being trucked downriver for release in an area near the confluence of the San Joaquin and the Merced rivers.
The same process will happen in reverse in three years for any fish that manage to make it back up the San Joaquin: They will be captured and trucked to the spawning beds above the dry section of river bed.
Schmitt said that even in undammed, pristine rivers only about three percent of juvenile salmon will find their way to the ocean, survive into adulthood, and return to their spawning grounds. He estimated that drought and other challenges this year might mean that less than one percent will survive, or as few as 80 to 150 individual fish.
In contrast, a century ago, historical sources say that 200,000 or even 300,000 fish each spring would come to spawn on the San Joaquin.
Scientists have confidence in their approach because for several years, they’ve had a similar program to reintroduce fall-run salmon on the San Joaquin. The spring run San Joaquin chinook have special significance because they are part of the Central Valley chinook population listed as threatened under the Endangered Species Act.
The fish released this spring won’t be coddled. Under the terms of the restoration agreement, authorities won’t release any additional water for their benefit.
And because they are considered an experimental population, they are exempted from Endangered Species Act provisions that would otherwise make it illegal to kill them by sucking them into giant water export pumps near Tracy.
Bill Jennings, executive director of the California Sportfishing Protection Alliance, said he hopes most of the salmon spend the summer hiding out in deep, cool pools in the river and don’t try to reach the ocean until the first rains come in fall or early winter.
Drought and aggressive water export goals make the lower San Joaquin River where it passes through the Delta particularly hazardous to small fish right now, he said.
“Even if they migrate down, even if they get to the lower river, they are going to go straight to the pumps,” Jennings said.
Another factor in whether the young salmon survive to spawn: what conditions are like in spring of 2017.
Under the restoration deal, Friant water users give more water to the river in wet years but don’t provide any water at all to the river in the driest 2 percent of years, Schmitt said.
“And lo and behold, we are in that kind of a year,” Schmitt said.
If 2017 is a wetter year, then water will be allowed to flow from Friant through the now-dry stretch of riverbed, making it possible for the grown-up salmon to “smell” the waters where they spent a balmy week as adolescents.
Those working on the restoration say it may take many years to achieve the program’s goal of 30,000 spring-run chinook returning each year.
“Reintroducing salmon to the San Joaquin isn’t something that is going to happen overnight,” Schmitt said.
Contact reporter Dana M. Nichols at (209) 607-1361 ordnichols@recordnet.com. Follow him atwww.recordnet.com/calaverasblog and on Twitter @DanaReports.