The Return of Salmon


| 5/21/2013 11:19:55 AM


Tags: environment, dams, salmon, Solutions Online,

 Glines Canyon Dam, February 2012, six months after the dam removal project started 
After the careful removal of two large dams, salmon are returning to Washington's Elwha River. 

This article originally appeared at Solutions Online. 

 

As the last block of concrete was pulled from the riverbed, the Elwha River in the Olympic Mountains of Washington State flowed freely for the first time in over 100 years. The river was historically one of the most productive salmon streams for its size in the Pacific Northwest. Four hundred thousand salmon once swam its length each year but, in the century since the dam’s construction, that number had fallen to a few thousand.1 Within months of the dam’s removal, nature has rushed back: over 200 salmon have already returned. The prospect of a river teeming with silverbacked salmon weighing over 45 kilograms each may no longer remain a hazy memory of local Native American tribes.

The Elwha dam removal project stands as one of the first large dams ever removed. The intent of removing the dams is to fully restore the Elwha River ecosystem and its native migratory fish species. In doing so, the Elwha dam project revived the debate of how to balance the conflicting demands of humans for both clean energy and healthy ecosystems. Previously, that debate has been weighted decisively in favor of dam projects. But with a greater understanding of the value of ecosystem services, the Elwha dam project may represent the start of a revolution in how we assess the West’s aging dam infrastructure.2 

The Elwha watershed was the traditional homeland of the S’Klallam Tribe, whose culture flourished on salmon from the river, among other natural resources. Against tribal will, construction of the Elwha Dam began in 1910 for the sole purpose of generating the first electricity in the region. The electricity powered several lumber mills and fueled economic development, resulting in construction of a second dam, the Glines Canyon Dam farther upstream, in 1927. The lower Elwha Dam did not have fish passage and the salmon runs declined from 400,000 per year to about 3,000 fish in the lowest eight kilometers of the river. Tributaries in the headwaters of the Elwha River were protected from further development in 1938 with the establishment of Olympic National Park. The impact on the S’Klallam Tribe was devastating for their culture and livelihood. A fishery that could be worth over $10 million was lost. The near disappearance of salmon in the watershed also had a cascading effect on the terrestrial ecosystem, where some 22 species of resident wildlife were affected, and over 90 species of migratory birds. The decomposing salmon carcasses have been shown to significantly contribute to the biomass of the forest itself, accounting for 20–60 percent of riparian biomass.1