Razorback Sucker Xyrauchen texanus in Lake Mead and Lake Powell Inflows

Authors: Ron Kegerries, Bradon Albrecht, Mark McKinstry

Year: 2016 (xlviii)

Abstract

Endangered Razorback Sucker Xyrauchen texanus populations have been reduced throughout their historic range during the last century. Dramatic changes in habitat through altered flow regimes, anthropogenic modifications, and the introduction of nonna tive fishes have limited recruitment. However, studies in Lake Mead since 1996, have tracked wild spawning and natural recruitment near inflow areas. Telemetry efforts at the Colorado River inflow area documented movement of sonic -tagged Razorback Suckers between Lake Mead and the Colorado River within the Grand Canyon. Additional larval and small-bodied fish sampling has documented reproduction within the Grand Canyon; however, in-river recruitment has not been documented. Similar Razorback Sucker investigations at the San Juan and Colorado rivers inflow areas of Lake Powell have also documented the presence of ad ult and larval Razorback Sucker in both areas. Given the results from Lakes Mead and Powell, we propose that inflow areas provide important, and perhaps necessary, habitat for natural Razorback Sucker recruitment and reproduction under current conditions. Thus, inflow areas, along with adjacent lacustrine and riverine habitats may be important locations for Razorback Sucker conservation and recovery efforts.