Humpback chub in the Grand Canyon have flourished under long-running restoration efforts. But now, exotic fish that prey on chub and other native fish have begun to slip through Glen Canyon Dam. It’s an unprecedented problem caused by the drought-stricken low levels of Lake Powell. KNAU’s Melissa Sevigny spoke with National Park Service fisheries biologist Melissa Trammell about her concerns.
Most people think of a dam as pretty effective barrier for fish. Can you explain why fish are able to potentially pass through the dam when the water level is low?
Lake Powell has been declining over the last 20 years, due to reduced runoff…