survival of migrating salmon smolts in large rivers with and without dams迁移鲑鱼的生存在大型溯河洄游河流和水坝.pdf

PLoS BIOLOGY Survival of Migrating Salmon Smolts in Large Rivers With and Without Dams 1* 2 2 1 2 3¤ David W. Welch , Erin L. Rechisky , Michael C. Melnychuk , Aswea D. Porter , Carl J. Walters , Shaun Clements , 3 4 3 Benjamin J. Clemens , R. Scott McKinley , Carl Schreck 1 Kintama Research, Nanaimo, British Columbia, Canada, 2 Fisheries Center, University of British Columbia, Vancouver, British Columbia, Canada, 3 United States Geological Survey, Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America, 4 Centre for Aquaculture and the Environment, University of British Columbia, West Vancouver, British Columbia, Canada The mortality of salmon smolts during their migration out of freshwater and into the ocean has been difficult to measure. In the Columbia River, which has an extensive network of hydroelectric dams, the decline in abundance of adult salmon returning from the ocean since the late 1970s has been ascribed in large measure to the presence of the dams, although the completion of the hydropower system occurred at the same time as large-scale shifts in ocean climate, as measured by climate indices such as the Pacific Decadal Oscillation. We measured the survival of salmon smolts during their migration to sea using elements of the large-scale acoustic telemetry system, the Pacific Ocean Shelf Tracking (POST) array. Survival measurements using acoustic tags were comparable to those obtain