Corps of Engineers Moves Salmon In Effort to Increase Fish Survival
Oct 1, 1999 12:00 PM
SOMETIMES the salmon in the Columbia River and its tributaries appear to be dam-ed if they do and dam-ed if they don't, but one project run by the US Army Corps of Engineers is trying to ease the impasse. The Corps collects fingerlings at upriver dams, loads them into tank trailers and barges, and transports them down river where they are released below Bonneville dam, the last one on the Columbia River. While the Corps owns the tank trailers, four Kenworth tractors are leased from PacLease in Portland, Oregon.
All of this is an effort to increase salmon survival in their migration to the ocean, which has become complicated by the construction of dams along the rivers. Juvenile salmon transit the dam system by going over the spillway or through the turbines. Mortality can be high for those in the turbines, so systems have been designed to divert fish away from the intakes, or to transport them down river.
"Fish are transported from around June 15 through December 15 at the McNary Dam on the Columbia River and from about March 25 through October 31 at the three Snake River dams," says Dave Hurson, Corps director of the project for the Walla Walla, Washington, District. "In 1998, we transported more than 18 million juvenile salmon and steelhead. Of those, 635,905 were moved by tank trailer.
"We truck at the beginning of the fish runs when there aren't a lot of fish and barge during the main body of the runs," he adds. "We return to the truck during the end of the runs when fish numbers are low again. Each of the three Snake River projects sends one truckload every other day. McNary Dam sends one truckload either every day or every other day, depending on the number of fish they are collecting."
In the down river trip to Chinook Landing, Portland, Oregon, the temperature of the tank water is automatically adjusted to acclimate the fish for release. It is regulated to be between 45 degrees F and 75 degreesF. Drivers stop periodically along the route to observe the fish condition and can report to biologists via cellular phone or two-way radio. They have been trained by the Corps to recognize fish trauma. Training also includes handling the tank trailer equipment for loading and unloading.
"We don't transport fish when it is snowing, but weather conditions run from very good weather to rainy," says Hurson. "From McNary Dam, it is all freeway driving. From the other projects on the Snake River, drivers wind along country roads with lots of hills until they reach the freeway at Umatilla, Oregon. Mileage varies from a low of about 185 miles from McNary to as many as 360 miles from Lower Granite Dam."
Insulated Trailers For over-the-road movements, insulated stainless steel West-Mark and Harris tank trailers provide a suitable temporary environment for the fish when they are collected from the river at the dams. West-Mark and Harris custom-fabricated and assembled almost all of the equipment for the specialized project, including the refrigeration unit and oxygen injection infusion system.
The tanks are divided into four compartments to reduce fish trauma that would be caused by water agitation from the vehicle motion. Compartment bulkheads do not totally enclose the fish, allowing them to move throughout the vessel. About 1,750 pounds of fish can be moved in the 3,500-gallon tank trailers.
The Corps maintains the tank trailers at a shop at McNary Dam. "We have two local shops where mechanics work on the refrigeration systems," says Hurson. "They also do other maintenance for us as needed."
Maintenance and routine service for the Kenworth tractors is included in the PacLease contract. Because of the fragility of the fish, the vehicles must be kept in good condition to avoid breakdowns during the movement from the various dams.
One example of the transportation project begins at McNary Dam, a hydroelectric structure located at the Washington/Oregon line south of Walla Walla, Washington. The Corps' $15-million bypass facility captures the fish when they enter the turbine intakes, moves them through a flume, and into the temperature-controlled tank trailers. Biologists monitor fish health as they pass through the state-of-the-art flume system. In addition, some hatchery fish have implanted electronic devices that enable biologists to track their progress. When monitoring equipment at McNary Dam picks up the signals, the fish can be removed, examined, and returned to the river, or transported with the rest of the captured load for the 3 1/2-hour trip down river.
"At McNary, we direct fish back to the river during the spring from April 1 until around June 15 when we start moving fish by barge," says Hurson. "We can move about 75,000 pounds per barge. Normally, we continue barging until around July 25 when we switch to trucking. This year, high river flows pushed a large number of fish downstream earlier than usual, so we began trucking earlier."
Moving fish down river to the ocean is just part of the migration process. Salmon swim from the ocean up the river to spawn and die, making their way past the dams via fish ladders built to ease their journey. Once spawned, orphaned juvenile salmon migrate from the freshwater spawning grounds to the salt water of the Pacific Ocean, all the time undergoing physiological changes to adapt to the change. As they reach maturity in the ocean, they head back for the return trip and the perpetuation of the species.
Giving nature a hand in the cycle became necessary when the fish numbers were reduced by overfishing, pollution, and other habitat damage, including navigation around the dams.
Joining the Corps in the work are various federal and state agencies, including the US Fish and Wildlife Service that is responsible for conserving, protecting, and enhancing fish and their habitats.
Although the fish are not listed for protection under the federal Endangered Species Act, concern has arisen about their preservation. Of particular interest is the salmonid species (chinook, coho, and steelhead) of the Pacific Northwest. Interest and concern alone were not enough to further conservation. Funding was needed for projects that would enhance the fish survival rate. As a result, excise taxes were levied on sporting arms and ammunition, archery equipment, sport fishing tackle, and motor boat fuels with the result that projects could be ongoing.
River Development Improving fish habitat has a long history with the Corps. The first federal funding for river development began with a Corps water resources program established in 1824 when Congress first appropriated money for improving river navigation, according to information from the Corps. In the Northwest, the lower Columbia was harnessed for multiple uses as early as 1896 when navigation locks were constructed. In 1938 Bonneville Lock and Dam provided hydropower and extended navigation. When Bonneville Dam was completed, fish ladders and bypass systems were installed.
McNary Dam was completed in 1954. Today at McNary Dam, 14 generators produce 1.2 million kilowatts of electricity at any given moment, producing 6.5 billion kilowatt hours each year to meet the demand of Northwest electricity consumers. Hurson points out that originally the dams were planned to enhance river transportation by the use of navigation locks. The hydropower projects were soon to follow. Agricultural and other products continue to be barged down river to the Port of Portland. River transportation, hydropower, agriculture, industry, and recreation all have brought challenges to fish habitats.
Today, the Corps manages nearly 2,000 water resources projects and has conducted more than $60 million in fisheries-related research since the 1950s. The transportation project in the Northwest is one of those programs that is expected to continue in the effort for salmon to survive and multiply.
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