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New antennas help biologists study salmon

WARREN, Idaho – Biologists studying salmon in the Pacific Northwest have for decades lost track of the fish just as they set out on life’s last leg, that final upstream lunge to spawn and die in the remote, backcountry streams and creeks in Oregon, Washington and central Idaho.

In many ways, an inability to track the fish has taught them even less about the first year of life, forcing researchers to make assumptions about salmon behavior and the influence habitat restoration and other expensive recovery programs are having on the threatened and endangered species.

That is changing, as crews have installed giant antennas in nearly two dozen rivers and streams across the region to track fish – at least those implanted with a microchip the size of a rice kernel – when they swim by. Researchers hope to learn more, much more, about the species they are desperately trying to preserve.

The biggest of these antennas, or arrays, was anchored recently in the rock and cobble of the South Fork of the Salmon River in a rugged corner of Idaho wilderness. Built of six, 20-foot-long sections, the array looks like a submerged sidewalk to the opposite bank.

For researchers like Chris Jordan, this network and the data it provides could help explain more about the mysterious behavior of salmon and the potential success of current and future restoration projects.

“We’ve only known part of this story for so long,” said Jordan, a research fish biologist with the National Oceanic and Atmospheric Administration’s Northwest Fisheries Science Center in Portland. “There are plenty of subtleties we need to understand much better.”

This latest technology is being paid for by the Bonneville Power Administration, which sells power generated at 31 hydroelectric dams in the Columbia River Basin and spends millions of dollars each year trying to improve habitat and bolster the numbers of salmon and steelhead trout.

The dams are at the center of a tense and complex debate over the best way to restore 13 salmon runs listed under the Endangered Species Act.

The dams are blamed by tribes, salmon fisherman and conservationists for killing salmon and steelhead on their journey as young fish to the sea and on the return trip as adults to reproduce in the same stream they were hatched. But decades of logging, irrigation, livestock grazing and human activity have also taken a toll.

In September, NOAA Fisheries submitted its latest blueprint for saving salmon. The plan, known as a biological opinion, recommends increased monitoring, intensifying habitat restoration and improving dam passage systems. It also restores consideration of tearing down four dams on a stretch of the Snake River in eastern Washington.

U.S. District Judge James Redden will decide whether the plan complies with the Endangered Species Act and is a viable tool for bolstering salmon numbers. Twice before Redden has declared previous versions inadequate.

Three of the new research antennas are now in place in the Entiat River basin in northcentral Washington, seven in the Wenatchee River and its tributaries in central Washington, eight in the John Day River system in northeastern Oregon and three in central Idaho’s Lemhi River basin.

Idaho’s South Fork of the Salmon River now has four, each at strategic points along the river and its main arteries. The biggest one is fastened with rock-climbing equipment downstream from the Payette National Forest’s Shiefer Campground; it cost BPA $125,000.

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The antennas are powered with a propane generator and solar panels. Information from passing fish is beamed by satellite to a database and posted in real time on a Web site available to the public. Federal, state and tribal agencies implant hundreds of thousands of the chips, known as PIT tags, each year in hatchery fish and wild fish captured at the dams or traps scattered across the region.

So far, the Shiefer Campground antenna has tracked 60 fish, most of them juvenile steelhead setting out on a 600-mile journey to the Pacific coast. Two of those fish were adults tagged in 2006 and once thought lost, but are now making their way back upriver.

But the big picture goal for the arrays is to help teach researchers more about the nuances and preferences of fish behavior.

For the first time ever, researchers are counting on the tracking system to help build more accurate estimates of juvenile fish and survival rates before coastal migration.

The data will be used to help pinpoint where in a river system juvenile fish prefer to spend their first year, or why certain stretches are preferable to others. Does one habitat improve juvenile survival rates over others? And are fish adapting to a changing environment or paying a price?

Researchers are also eager to find out if the millions of dollars spent each year on habitat improvements and managing stream flow really make a difference, or if those resources should be focused elsewhere. BPA spends about $300 million annually on habitat restoration, buying and protecting habitat and researching fish protection.

“We’re spending millions of dollars on restoration work without having a tool to measure actual benefits,” Jordan said “We can model this all we want, but having these arrays. ... throughout a watershed, can show where a fish goes throughout its life cycle. ... we can ask ourselves questions about which strategies are most successful at producing the next generation.”





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