July 17, 2016--How hydroelectric power kills insects, and why that matters (Pacific Standard)

Hydroelectric power is a well-established and low-cost form of renewable energy that doesn’t produce greenhouse gases. But, like any power source, it also has its dark side: A common hydroelectric power practice known as hydropeaking can be deadly to insects, with serious downstream consequences for a dammed river’s ecosystem, according to a paper in BioScience. This is, of course, not the first time researchers have identified negative environmental impacts associated with damming rivers. Building a big wall across a river interferes with salmon and other fishes’ migration, even with age-old workarounds like fish ladders. But, United States Geological Service biologist Theodore Kennedy and his colleagues point out, the danger to ecosystems could go beyond an immediate threat to fish populations. In particular, no one’s really looked at the consequences of hydropeaking, in which dam operators release more water through the dam during the day to produce more electricity when it’s most in demand. Like the underlying electricity demand, the hour-to-hour changes in river flow are enormous. In some places, river flows change by as much as a factor of 10 over the course of the day, leading to a cycle of drying and re-wetting along the shore of a river. That creates intertidal zones more akin to what you’d see at an ocean beach than a typical river. To view the full article visit the Pacific Standard.