DFG Releases Three Million Juvenile Salmon Near Mouth Of American

DFG Releases Three Million Juvenile Salmon Near Mouth Of American

by Dan Bacher

The California Department of Fish and Game released three million young Chinook salmon (“smolts") at the mouth of the American River during the week of May 10 as part of an effort to improve the return of adult salmon to the American - and prevent the fish from straying into other systems.

The DFG raised all of the fish at Nimbus Fish Hatchery on the lower American in Rancho Cordova. The new release site was selected based on new information and studies that show “young salmon released near the mouth of their home river are more likely to return to that river two to five years later to spawn,” according to Harry Morse, DFG spokesman.

“Our goal is to increase the spawning returns to the lower American River of fish reared at Nimbus Hatchery,” said Senior Environmental Scientist Joe Johnson of the DFG’s Central Region. “Last year more than half of the salmon returning to the American River originated from the Mokelumne, Feather or Upper Sacramento rivers. This year we’re taking clear steps to ensure that more fish return to the waters where they were raised.”

The release of fish occurs at a time when Central Valley salmon are in their greatest crisis ever, due to a variety of factors led by increased water exports out of the California Delta in recent years. Only 39,530 adult fall chinook salmon returned to the Sacramento River and its tributaries in 2009, the lowest run on record, spurring the closure of ocean recreational and commercial fishing in 2008 and 2009.

A total of 5,756 chinook adults and 1,126 jacks returned to Nimbus Fish hatchery in 2099. This is much better than the 3,300 adults and 453 jacks that came back to the hatchery in 2008, but pales in comparison to the runs of previous years.

For example, 24,723 adults and 3,437 jacks returned to the facility in 2005, while 15,493 adults and 21,390 adults came back the previous year.

The DFG will track the journey of salmon down the river through the use of coded wire tags that show when and where they were tagged and released. Starting in 2007, 25 percent of 32 million salmon smolts released in the Sacramento River system were imbedded with these minute tags.

"A major goal of river releases is to improve the genetic integrity of each river’s salmon populations," noted Morse. "DFG biologists are working to decrease straying rates between rivers, where adult salmon return from the ocean and spawn in a different river than the one they were born in."

Based on the coded wire tag retrieval data, 72 percent of the fish that returned to Nimbus were from other hatcheries, according to Morse. The crews who went out in boats on the river to count carcasses found that 73 percent of the fish were from other hatcheries.

“We’re talking about a very high percentage of strays,” said Morse. "To ensure the highest survival rates of the smolts on their down river migration, DFG and the Bureau of Reclamation (BOR) are coordinating release timing, flows and closure of the Cross Channel Gates operated by BOR during the short migration period.”

The Jibboom release site, located slightly down stream of the mouth of the American River at Discovery Park, was selected after biologists reviewed release and return data from numerous sites. They found that a large number of smolts released from the Jibboom site in previous years were returning to the American River, according to Morse.

Dick Pool, administrator of http://www.water4fish.org, agreed that straying is a problem on the American, but said he was surprised that the DFG had released them at the mouth of the American rather than at another location.

“I am concerned that they released 3 million at the mouth and while only 1 million are going into the acclimation pens in San Pablo Bay,” said Pool. “Maybe San Pablo Bay is too far to release the fish from the American, but they need to take the fish somewhere beyond the reach of the Delta pumps.”

Pool noted that several years ago there was a problem with substantial straying of Mokelumne River hatchery fish, so the DFG started releasing the fish at Jersey Point on Sherman Island. This way, the fish were released away from the reach of the pumps but were still put in their natal water in the San Joaquin River system.

“By releasing the fish at the mouth of American, the salmon still have to go past the Delta Cross Channel Gates and Georgiana Slough,” said Pool. “Even when the Cross Channel gates are closed down, Georgiana Slough is a big problem, since the fish that go into the interior Delta via the slough eventually end up in the pumps.”

Twenty percent of the Sacramento River Chinook salmon are drawn into Georgiana Slough on their downstream journey, according to the federal salmon biological opinion. “There is virtually no survival once they are pulled into the Central Delta, where there is little cover, little food, loads of predator and poor water quality. This water flows straight to the state and federal pumps,” he said.

Pool suggested instead releasing the Nimbus salmon smolts at Rio Vista or Collinsville on the Sacramento River or in Steamboat Slough. “This way they would be kept in the Sacramento River system, but would be able to bypass Georgiana Slough and the Cross Channel Gates,” concluded Pool.

Ironically, while the DFG is trying to reduce the amount of stray salmon into the river, fish advocates say the future of American River salmon and steelhead is at risk because there are no enforceable temperature standards incorporated into the Bureau of Reclamation’s water right for the operation of the Folsom and Nimbus dams. This is in spite of a tentative agreement reached with the Water Forum, Friends of the River, Save the American River Association (SARA) and other conservation groups three years go.

“The Bureau also has no intention to voluntarily modify its Folsom Dam operations to meet the recommendations of the National Marine Fisheries Service (NMFS)) Biological Opinion (BO.),” said Felix Smith, SARA board member and the retired federal fisheries biologist who exposed the Kesterson Wildlife Refuge disaster during the early 1980s, in his recent paper, “Area of Origin Protection: Our Fisheries and Other Public Trust Interests.”

The Bureau stated in a letter on January 12, 2010 to NMFS that it would follow the flow management standard (FMS) and when additional water is needed to meet the FMS, (b) (2) water will be used. The 800,000 acre-feet of water dedicated to fish, wildlife and habitat restoration measures under the Central Valley Project Improvement Act (CVPIA) of 1992 is referred to as (b) (2) water.

The Bureau also said it will strive to achieve the temperature targets of 60 DF, with 56 DF as early as possible in November.

“In reality, the Bureau has not formulated base line criteria for public review and comment regarding the use of CVPIA Section 3406 (b) (2) water,” Smith stated. “In addition, temperature excursions above 67 DF to 71 DF are common on the American River during the summer months.”

“Water temperatures of 65 DF to 67 DF have extended into October and November,” added Smith. “Such temperature affects holding adult Chinook salmon. Latent embryonic mortality and growth abnormalities are associated with thermal stress when adult Chinook salmon are exposed to waters above 63.5 DF."

Pre-spawning mortality and incidence of disease is also increased among American River salmon and steelhead, due to the failure to adopt water temperature standards.

“Temperatures above 65 DF have extended for several weeks well into the fall months," said Smith. "Water temperatures protective of steelhead juveniles, 65 DF or less, have been exceeded 7 out of 9 years during the period 2001 through 2009."

As the DFG attempts to reduce the problem of straying by Nimbus Hatchery Chinooks, the Bureau of Reclamation under the Obama adminstration is apparently refusing to deal with the larger issue of adopting long-needed, enforceable water temperature standards on the American River to protect imperiled salmon and steelhead.