Salmon Wetlands Slipping Away

July 9 -- Ayesha Gray sits sheathed in chest waders and heavy boots — perfect gear for slogging through the water-filled channels of central Oregon's SalmonRiver estuary.

Despite the inconvenience of working in waist-deep mud, Gray feelsprivileged to be studying the estuary's wetlands. Throughout the PacificNorthwest, wetland habitats in estuaries have been destroyed or degraded.

This is bad news for juvenile salmon, which rely on these marshyhabitats to make the transition from freshwater to ocean-dwellinglifestyles.

"People once thought of wetlands as worthless wastelands," says Gray, adoctoral student in fisheries at the University of Washington in Seattle.

But for salmon, whose stocks have been recently added to the federalEndangered Species list, nothing could be farther from the truth.

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Different species of salmon rely on estuarine wetlands to varying degrees.While some spend only two or three weeks of their youth in the estuary,others may spend up to four months in the same locales before heading out tosea.

Estuaries are important to all ocean-going salmon, says Dan Bottom of theNational Marine Fisheries Service. The water in estuaries is saltier than infreshwater rivers or lakes but not as salty as the ocean, he says. The Salmon River estuary serves as a staging area where salmon can graduallyadjust to more briny ocean conditions.

The estuaries offer salmon more than a transition environment, says CharlesSimenstad, a research associate professor at the University of Washington,who, with Gray and Bottom, has been studying the Salmon River estuary since1997.

"For one thing, the murky waters of estuaries make it harder for blue heron,bald eagles and other salmon-eating predators to spot the juvenile fish," heexplains.

With estuaries in decline, it's not surprising the species and typesof salmon that are most wetland-dependent are also the most endangered. Lastyear, the federal government conferred protection under the EndangeredSpecies Act to two of these — the Hood Canal summer chum and Puget Soundfall chinook salmon of Washington state.