Category Archives: Salmon

Why do Pacific Salmon Die After Spawning?

The upriver salmon run is one of nature’s great migrations. Each year mature salmon make the long journey back to their natal river to reproduce, just once. For the five species of Pacific salmon (Chinook, chum, coho, pink, and sockeye), this arduous journey is a race against the clock that ends in a fleeting romance and ultimately death.

The answer to why they die, it turns out, hinges on a problem every animal on Earth has had to solve.

“Every kind of organism has evolved to solve the problem of balancing how much energy to put into surviving to first reproduction and how much energy to put into surviving to reproduce repeatedly,” said Steve Lindley, the director of NOAA’s Fisheries Ecology Division.

“Salmon are one of the extreme cases where they put everything into reproducing just once, and then getting old and dying almost immediately thereafter (a common strategy among insects but much less so for vertebrates).”

The reason for this, Lindley suggested, has to do with the difficult upriver migration salmon make back to their own spawning location. Flipping their bodies in the air and hurling themselves against the downward flowing water is no easy feat and one that is energetically exhausting. Because of this, salmon must fully develop in the ocean and build up fat reserves. Once they enter the river there is little food to eat and they stop investing in the maintenance of their bodies.

“The proximate reasons have to do with DNA switches,” Lindley said. “Essentially many of the activities that operate in immature salmon to allow them to maintain their health, grow and mature are turned off after maturation, and without maintenance they pretty rapidly ‘fall apart’.”

An alternative for these salmon species would be to spend more time in the ocean, accumulating food and energy so they are then able to migrate back after spawning. But this increases their risk of dying before getting the chance to spawn and for Pacific salmon, this is a risk too great.

From BayNature.org >>>

Volunteers sought to repair trails damaged by American fire

Tahoe National Forest officials have reopened parts of two popular trails damaged in August by the American fire and are seeking volunteers to help rehabilitate the remaining trail segments.

The Western States Trail is open between Michigan Bluff and Deadwood Cemetery, and OHV Trail Loop 6, also known as Forest Service Trail 11E44, is open west of Deadwood Ridge Road.

The entire fire area, including all trails and roads within it, will remain closed for public safety until May 1, said Gwen Ernst-Ulrich, forest spokeswoman.

The fire, northeast of Foresthill in Placer County, burned 27,440 acres within the forest’s American River Ranger District and surrounding properties, including three historic buildings at the Pacific Slab mine.

Eighteen of the 25 miles of the Western States Trail damaged by the fire have been rehabilitated, Ernst-Ulrich said, and efforts are underway to winterize the remaining seven miles to minimize erosion.

Since 1974, the trail has been the site each June of the internationally known Western States 100-Mile Endurance Run from Squaw Valley to Auburn and, in August, the Tevis Cup Endurance Ride.

The remaining damaged seven-mile segment, between Last Chance and Deadwood, is listed on the National Register of Historic Places. It includes two fire-damaged bridges across the northern portion of the middle fork of the American River canyon.

“The (ranger) district is looking at alternate routes for these events if the swinging bridge that crosses the river is not able to be used in time,” Ernst-Ulrich said. “Thousands of other recreationists use this popular trail annually.”

More at SacBee.com >>>

Salmon leap at a chance to spawn at hatchery

With a swish of its tail, a salmon jumps more than 20 steps – one at a time – to the top of the Nimbus Fish Hatchery ladder Monday as the annual fall migration takes place. Nikolai Andryhoushkin, pictured, of Sacramento photographs the event, vital to the survival of salmon and steelhead in the lower American River.

Once they make their way up the fish ladder, the salmon are sorted and spawned on a table. An average salmon female has more than 5,000 eggs. The eggs are housed in the spawning building and the fish are raised until they are 4 to 6 inches long before being released. Steelhead are also raised at the hatchery, just off Highway 50 in Rancho Cordova.

Since 1958, the Nimbus Fish Hatchery has been successfully providing mitigation for the loss of natural fish habitat in conjunction with the U.S. Fish and Wildlife Service, the state Department of Fish and Game and the U.S. Bureau of Reclamation.

More at SacBee.com >>>

Salmon ladder opens at Nimbus Hatchery on Monday

Chinook_Nimbus

The fish ladder at Nimbus Hatchery on the American River opens Monday, and salmon are reportedly piling up waiting to use it.

The Chinook salmon run is an annual spectacle on the American River as the giant fish return each fall from the ocean to spawn. This year, the run that continues into December should be noteworthy, because the salmon population is expected to rebound significantly from recent lows.

The fish ladder leading to the hatchery is a great place to view the run, and visitors can stand alongside the ladder while the big salmon jump into the hatchery. The ladder is scheduled to open at 10:45 a.m. Monday.

“There will definitely be fish,” said Andrew Hughan, a spokesman for the California Department of Fish and Wildlife, which operates the hatchery.

More at SacBee.com >>>

 

Researchers say California salmon experiment a success

Flooded rice fields appear capable of serving as substitutes for now-depleted wetlands and helping California’s Chinook salmon population recover, researchers have concluded.

In a report submitted to the U.S. Bureau of Reclamation, the researchers said salmon raised in replicated rice fields near Sacramento as part of their experiments were the fattest and fastest-growing salmon ever documented in freshwater in the state.

“We’re finding that land managers and regulatory agencies can use these agricultural fields to mimic natural processes,” study co-author Carson Jeffries, field and laboratory director of the University of California, Davis’ Center for Watershed Sciences, said in a news release on Thursday.

The state Department of Water Resources and a nonprofit called California Trout also participated in the report, which is dated Oct. 1.

Juvenile Chinook salmon in California’s Central Valley have traditionally been reared in wetlands, where they fatten up before heading off to the ocean. A salmon’s size is an indicator of its likelihood of returning to spawn as an adult, according to the study.

The goal of the researchers’ experiment was to determine whether rice fields flooded between harvests could stand in for the wetlands that once filled the area.

More at MercuryNews.com >>>

Salmon restoration in American River worries some kayakers, rafters

A project to improve salmon spawning habitat in the American River has some kayakers and rafters concerned that they may lose a favorite area of rapids.

The project, which started Sept. 3, involves using bulldozers to place 6,000 tons of large gravel cobbles in the riverbed near River Bend Park and Arden Way. The gravel is needed to create spawning habitat for wild chinook salmon, which make nests for their eggs in the rocks.

The work is occurring directly downstream from the parkway pedestrian bridge between River Bend Park and William Pond Recreation Area. This stretch of river includes the Arden rapids, an area favored by kayakers and rafters.

“It was a bit of a surprise to see all that rock in there and basically changing the whole flow of the river,” said Sven Lund, organizer of the SacYakkers kayak club. “For people going in it for the first time, it seems like an unnatural flow to the river and they will get caught on the gravel.”

Lund and others eventually learned that the right side of the river has water deep enough to pass.

More at ModBee.com >>>

Salmon habitat project begins on American River today

The latest phase of a project to restore salmon spawning areas in the American River begins today near River Bend Park in Sacramento.

The project involves spreading gravel in the riverbed so migrating wild Chinook salmon have more room to create “redds”, or nests for their eggs. The goal is to replenish gravel that would have naturally washed downstream, but has been blocked for decades by Folsom and Nimbus dams.

Led by the U.S. Bureau of Reclamation, which owns the dams, the project is in its sixth year and has already proven successful by increasing the number of documented redds.

About 6,000 tons of gravel will be added to the lower American River during this year’s phase of the project. Some 5,500 square yards of improved spawning habitat will be created. This year’s work is estimated to cost $400,000.

Work hours will be Monday through Friday from 7 a.m. to 5 p.m. All work is located immediately downstream from the pedestrian bridge at River Bend Park. The work is expected to be finished by Friday, Sept. 27.

More at SacBee.com >>>

 

Folsom Lake Concerns: San Juan Water District Adopts Voluntary Restrictions

Customers of San Juan Water District in are being asked to reduce their water use 5 to 10 percent due to concerns that Folsom Lake may not be able to serve normal demand.

The district’s board of directors last week adopted a Stage 2 Water Alert, which calls on customers to take voluntary actions to conserve water. The district serves Granite Bay and portions of Roseville, Folsom and Orangevale.

“We’re encouraging residents to avoid all unnecessary and wasteful uses of water,” Judy Johnson, the district’s customer services manager, said in a statement.

The request comes after the driest January-through-June period in the northern Sierra Nevada region in history. Lack of snowfall and resulting poor runoff has left many California reservoirs in a depleted state, including Folsom Lake. The lake supplies most of the water used by San Juan customers, and there is mounting concern it will not be able to meet demand next year.

More at SacBee.com >>>

 

Placer County Water Agency: Water Forum Transfer Partnership

The Placer County Water Agency (PCWA) Board of Directors on Thursday (Aug. 15) approved a memorandum of understanding (MOU) with the East Bay Municipal Utility District (EBMUD) to move forward on development of a potential long-term water transfer that meets their mutual water supply reliability interests and improves the ecosystem of the lower American River.

The potential transfer of water from PCWA’s Middle Fork American River Project would further affirm PCWA’s Water Forum stewardship commitments to the lower American River and likewise assist EBMUD in strengthening its water supply reliability needs.

Under the PCWA board action, staff will develop details of the transfer, including duration and financial terms, for future board consideration.

PCWA, as one of many local water purveyors in the American River basin, is a signatory of the Water Forum agreement.  The agreement outlines a multipart plan to increase diversions from the American River to meet increasing future demands locally while at the same time implementing dry year actions to protect the lower American River’s aquatic resources, including Chinook salmon and the federally-threatened Central Valley steelhead.

More at RocklinToday.com >>>

American River Flow Changes This Week For Fish Weir Installation

Flows will change in the American River this week while federal officials install a fish weir below Nimbus Dam to prepare for the fall salmon migration.

Overnight Wednesday, the U.S. Bureau of Reclamation planned to drop American River flows from 2,500 cubic feet per second to 1,000, then return to 2,500 during the day. This is planned so crews can do maintenance on the weir structure.

Then on Friday starting at 1 a.m., flows will be dropped again to 1,000 cfs to install the weir, and increased back to 2,500 cfs by afternoon.

These actions will change the river elevation by about 14 inches, as measured in Fair Oaks. People recreating and traveling along the river are advised to use caution near the water’s edge.

The weir is installed across the river annually to guide spawning fall-run Chinoook salmon into the Nimbus Hatchery fish ladder.

More at SacBee.com >>>