The spillover effect of dams on salmon

Christina Murphy is not chasing rainbows. She is exploring how best to manage dams to protect salmon.

The majority of Pacific Northwest hydropower dams are located on rivers that support threatened and endangered salmon. These dams are managed for power generation and flood control, and they form large reservoirs with physical and chemical properties that are different from the free-flowing rivers they displace.

[caption caption="Christina Murphy, a graduate student in Ag Sci’s Fisheries and Wildlife department, examines reservoir levels and their effect on salmon growth and survival. (Photo courtesy of Christina Murphy.)"] [/caption]

Murphy is using data collected from several reservoirs in the Willamette Basin—both before and after hydrologic changes— and models of reservoir ecology to explore how changes in water levels in the reservoirs may affect food webs, water quality, and salmon growth and survival.

A doctoral student in fisheries and wildlife at Oregon State, Murphy received a prestigious STAR fellowship from the U.S. Environmental Protection Agency. The fellowship program, Science to Achieve Results, suggests that Murphy’s research could have important, real-world application to management of hydropower dams in the Northwest and beyond.

“The Pacific Northwest relies on hydropower for more than half of its electricity,” Murphy said. “Improved understanding of how water-level fluctuations affect the ecological mechanisms of these reservoirs is critical to ensure ecologically sound practices for the long-term operation and greening of our hydropower infrastructure.”