Wildlife managers in Grand Canyon National Park are trying to find new methods to control invasive fish species in the Colorado River.
The Arizona Daily Sun reports numbers of brown trout and green sunfish have been rising in the river over the past few years. Those fish prey on and compete with native species. One of the Park Service’s proposals involves undergoing long-term “electro-fishing,” a process that uses electrical currents to stun fish until they float to the surface, then removing the non-native fish. But electro-fishing has prompted criticism from Arizona state wildlife officials and fishing groups. The park service has a range of other ideas, including genetic population controls, reducing water for the invasive species to spawn, and introducing chemicals to target the fish. A public comment period to suggest further alternatives ends on Friday. After that, park officials will sort through the options and eventually decide on a course of action.