Go Fish: Investments in Salmon and Sockeye Protection at Hydroelectric Dams are Paying Off
More than 2.5 million mature salmon swam through the Bonneville Dam on their way to spawn in the Columbia and Snake Rivers and their tributaries last year. That’s the highest number of fish since the Bonneville Dam was built more than 75 years ago, back in 1938. After decades of stagnant returns, the Pacific Northwest salmon population has been steadily growing over the past fifteen years.
But this growth has not been easy. Widespread restoration efforts began back in the 1990s, when petitions to the Endangered Species Act added 12 species of salmon and steelhead for protection due to falling fish counts.
Throughout their lifecycles, salmon and steelhead face a number of threats, from their journey as juveniles to the Pacific Ocean, to survival in the ocean, and then back to their native rivers and streams to spawn again. One of the many dangers to the fish can be dams along their paths.
The Columbia and Snake Rivers are home to eight federal hydroelectric dams. Hydroelectric power accounts for 46% of the Pacific Northwest’s energy resources and is the single largest power source for the region. Because hydropower is a clean energy source and carbon-neutral, unlike power produced by burning coal or petroleum, taking out the dams was not a viable option, even to restore salmon stocks.
Instead, the dams have been making large investments in retrofitting to protect the fish. And their efforts are paying off. In 2014, nearly 3,000 Snake River sockeye, which were nearing extinction back in the 1990s, were counted passing through Lower Granite Dam on their way to spawn; that’s almost 30% more Snake River sockeye than the previous record, set in 2012.
Having dams that are safer for fish has contributed to these encouraging sockeye returns. After years of innovation and new changes, an average of 97% of juvenile fish survive through the dams today. Investments in these new technologies total more than $14 billion, funded largely by Northwest families – 10 to 20% of a Northwest family or business’s electricity bill is used for fish and wildlife programs.
Innovations for fish protection include fish ladders, which help the adult fish move upstream to spawn, fish slides, for diverting fish over the dam, and mechanical bypass systems, to send juvenile fish away from the turbines and around the dam. Additionally, by using high-efficiency turbines and decreasing hydropower operations during peak migration times, more juvenile and adult fish experience safe passages through and around dams. As a result of these measures, the National Oceanic and Atmospheric Administration (NOAA) Fisheries’ research suggests that the survival rates of fish in rivers with hydroelectric dams are approaching those of rivers without dams.
Salmon and sockeye still face numerous dangers. Four out of five fish mortalities occur in the ocean, where protection is much more difficult than simply investing in fish ladders. And, fish runs fluctuate year-to-year based on the survival rate of juveniles, oceanic conditions, and a number of other factors unrelated to dams; while 2014 signified record-breaking returns, scientists are already looking toward 2015’s fish run.
However, 2014’s fish runs are particularly encouraging for Oregon’s salmon industry, which generates more than $18.4 million for the economy. With continued growth in fish returns, the salmon industry can continue to prosper in Oregon, sustainably catching and harvesting fish for generations. Through dams that are safer for fish, Oregon and its economy can benefit both from hydroelectric power and a healthy fish population.