BUZZ

Changing Water Flow in Grand Canyon Leads to More Bugs

The flows are part of an experiment to support endangered fish.

An experiment to change the flow of water from a dam near the Arizona-Utah state line appears to have boosted the number of aquatic insects near the Grand Canyon. Scientists found that releasing low, steady flows of water gives the eggs that bugs lay just below the water’s surface a better chance of survival. The water flows are part of a larger plan that could help native fish such as the endangered humpback chub and non-native trout survive. The plan allows for high flows of water to push built up sand in Colorado River tributaries through the Grand Canyon, as well as other experiments. Researchers are recommending three consecutive years of increased bug flows in order to support the fish. “It’s a powerful reminder that flows really matter, that just a couple days a week of steady flow can illicit massive emergence,” said Kennedy, a research ecologist with the U.S. Geological Survey.