River Tour Tracks Salmon Migrationby Cassandra Profita
The Daily Astorian, September 10, 2009
NOAA scientists research fish populations in Columbia River estuaries
Scientists at the National Oceanic and Atmospheric Administration Point Adams research station in Hammond are tracking Columbia River salmon from the dams on the Snake River tributary to the bellies of birds on the Pacific Ocean...and beyond.
Some of their research is narrowly focused on habitat restoration sites in Columbia, Pacific and Wahkiakum counties while other projects stray as far as the flocks of sooty shearwaters - to nesting colonies in New Zealand.
On Wednesday, NOAA's Point Adams team took independent scientists from across the U.S. and Canada to research sites in the estuary for an up-close view of their workplace. The trip was a prelude to the Northwest Power and Conservation Council's Columbia River Science Policy Exchange, which is being held today and Friday at the Holiday Inn Express in Astoria.
The exchange is designed to allow scientists to share information and ideas about fish and wildlife restoration with members of the Council, the scientific community and fish and wildlife managers who are working to revitalize 13 threatened and endangered species of salmon and steelhead in the Columbia River Basin.
Tour highlights local projects
Scientists toured the estuary Wednesday on board three research vessels Point Adams fisheries biologist Dick Ledgerwood uses to track migrating juvenile salmon and steelhead. Ledgerwood takes a snapshot of fish passing below using a specialized underwater antenna built into an open-ended trawl net stretched between two boats.
As the fish pass through the net, the antenna picks up a signal from passive integrated transponder (PIT) tags inside the fish and delivers encoded data to an on-board computer. The data identifies individual fish and gives him an idea of how many salmonids are surviving the journey from upriver dams - which also track fish passage - and how long it takes them to make their way down the river.
Point Adams researchers also track the PIT-tagged fish by scanning bird droppings on East Sand Island and other nesting sites in the estuary. Their research shows the birds - namely colonies of around 20,000 Caspian terns and 22,000 double-crested cormorants - consume up to 4 percent of the Columbia River's 1.5 to 2.5 million tagged juvenile salmonids. Scientists estimate the birds on East Sand Island consume at least 25 to 45 percent of the lower Columbia tule fall chinook.
On Wednesday's tour, NOAA research assistant Beth Phillips reported on her work with Point Adams fishery biologist Dr. Jen Zamon. Their team travels to sea at night to capture resting sooty shearwaters and common murres and sample their stomach contents. They also tag shearwaters with satellite tracking devices to follow their movements from the mouth of the Columbia. The research not only paints a picture of the seabirds' diet but also reveals their range of movement and responses to ocean conditions and climate. Genetic analysis of salmon bones in the birds' stomachs tells scientists the fish species and river of origin, as well as how many individual salmon each bird has consumed.
Mitigation funding is key
Funds for much of the Point Adams research comes through the Northwest Power and Conservation Council, which decides how best to spend hundreds of millions of dollars Bonneville Power Administration has earmarked for mitigating the environmental impacts of hydroelectric dams.
The Council's Independent Scientific Review Panel examines the integrity of fish and wildlife restoration proposals and tracks hundreds of ongoing projects. The Independent Scientific Advisory Board makes recommendations to the Council on funding decisions. Members of both boards attended the tour Wednesday.
Many of the BPA-funded estuary projects are coming up for review in 2010, said Eric Loudenslager, chair of the review panel, and "it's always helpful to have the lay of the land."
Scientists are increasingly recognizing the estuary as a critical nursery for juvenile salmon and steelhead from all 13 Columbia Basin stocks listed as threatened or endangered. Dam mitigation projects include dike breaches in the lower river that restore converted wetlands and reopen rearing habitat to young salmonids.
How much does it help?
Dr. Curtis Roegner, a research fisheries biologist at NOAA's Point Adams lab, talked Wednesday about his research on the cumulative effects of multiple habitat restoration projects in the lower Columbia. He's monitoring the Kandoll Farm tidal reconnection in Wahkiakum County's Grays River watershed, where a dike breach in 2004 has brought the water back onto a converted pasture along with thousands of baby salmon. Between now and 2011, Roegner and others will continue to sample the habitat at Kandoll Farm and other restoration sites to help illustrate their larger significance for salmon recovery plans in the Columbia River Basin.
U.S. District Judge James Redden added a new focus on the role of estuary projects this spring in the ongoing court battle over Columbia River dam management when he zeroed in on an unanswered question that has serious implications for dam mitigation funding decisions: How much is habitat restoration contributing to salmon survival?
Loudenslager said projects funded through the Council have to make an effort to quantify the benefits to fish and wildlife, but determining exactly what survival benefit they're bringing altogether is still unknown.
"It's a difficult question," he said, "and one that's very, very hard to get a handle on."
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