The use of backwaters and the conservation plan for native fishes of the lower Colorado River

Authors: Brian R. Kesner, Paul C. Marsh, Thomas E. Dowling

Year: 2010 (xlii)

Abstract

Use of backwater or off-channel environments free of nonnative fishes is a central component of conservation plans for bonytail Gila elegans and razorback sucker Xyrauchen texanus in the lower Colorado River and the current focus of efforts on behalf of these species within the multi-agency long-term Lower Colorado River Multi-Species Conservation Program (LCRMSCP). As part of a larger study to investigate ecological and genetic factors involved in the success of the conservation strategy, two backwaters on Lake Mohave, Arizona-Nevada, were each stocked with 200 PIT tagged and fin clipped razorback sucker in February, 2010. Fish were allowed to grow and reproduce, and were harvested in September, 2010. Survival for stocked fish was greater than 75% and more than 1,000 young-of-year razorback sucker were produced in each backwater. The experiment is presented as an example of how off-channel habitats free of nonnatives can work, although larger applications of this technique to date have been wrought with logistic hurdles and agency intransigence.