8131 - Laserfiche WebLink

Home Browse Search

3 iMcielle?- ???1 l?q -^-°- A Program To Maintain The Endangered Razorback Sucker In A Highly Modified Riverine Habitat. -?. Environmental Enhancement of Water Projects G. Mueller] T. Burke2 M. Hornz ABSTRACT Proceedings from the 1993 Seminar Sacramento, California October 14-16,1993 Sponsored by U.S. Committee on Irrigation and Drainage Co-Sponsored by Bureau of Reclamation Although considered a riverine fish, the endangered razorback suckers last stronghold is in Lake Mohave, a reservoir on the Colorado River. Suckers successfully spawn in the reservoir each spring, but predation on the larvae by nonnative fish prevents successful recruitment. This relic population is composed of suckers over 40 years old. Unless this bottle neck to recruitment can be corrected the population will disappear within the decade. The Native Fish work Group was formed in 1990 through cooperation of six agencies to develop a management plan to save this reservoir population. Within the context of the plan, we are isolating coves and backwaters of the reservoir and using them to rear fish in a predator-free environment. Suckers are allowed to grow unmolested to a size large enough to insure survival before being released into the reservoir. In 1992, 153 suckers exceeding 10 inches (25 cm) in length were tagged and released into the reservoir. Five of these suckers were recaptured 6 months later demonstrating there is survival. Survival rates in the reservoir will be used to guide future stocking efforts. Edited by Wayne O. Dcason Bureau of Reclamation Susan S. Anderson U.S. Committee on Irrigation and Drainage Published by U.S. Committee on Irrigation and Drainage 1616 Seventeenth Street, Suite 483 Denver, CO 80202 (Y? Telephone: 303-628-5430 Fax: 303-628-5431 Research Fishery Biologist, U.S. National Biological Survey, Denver, CO 80225 2Fishery Biologists, U.S. Bureau of Reclamation, Boulder City, NV 89006 17 -r