Non-Native Fish Control Downstream
from Glen Canyon Dam
The Bureau of Reclamation, Upper Colorado Region, proposes to control non-native fish in the Colorado River downstream from Glen Canyon Dam in an effort to help conserve endangered fish. The non-native fish control efforts would be located within Glen Canyon National Recreation Area and Grand Canyon National Park, Coconino County, Ariz. The purpose of the action is to minimize the negative impacts of competition and predation on an endangered fish, the humpback chub (Gila cypha) in Grand Canyon. The action is needed because competition and predation by rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) are reducing survival and recruitment of young humpback chub and threatening the potential recovery of the species. Rainbow trout and brown trout are not native to the Colorado River Basin and have been introduced into the region and are managed as sport fish.
This action is being conducted through the Glen Canyon Dam Adaptive Management Program. Accordingly, an additional purpose of this action is to evaluate, in an adaptive management framework, the effectiveness of conducting these nonnative fish control actions in conserving the endangered humpback chub and other native fishes Reclamation proposes that this action start in 2011 and extend to 2020. Starting the action in 2011 addresses the importance and need for implementing non-native fish control activities as soon as possible in order to address the ongoing threat to the humpback chub, as well as a number of cultural and socioeconomic concerns and issues, further described in the Issues section of this EA. .