Assessing a capture-translocation strategy to improve spawning migration connectivity of Razorback Suckers, Xyrauchen texanus, in the San Juan River

Authors: Matthew Bogaard, Keith Gido, Mark McKinstry, Casey Pennock, Adam Barkalow, Benjamin Schleicher, Brian Hines, Katherine Creighton, Sophia Bonjour, Jerrod Bowman, T. Yazzie

Year: 2021

Abstract

In the southwestern United States, decades of water diversions, construction of large impoundments, and loss of floodplain habitats have all contributed to a highly fragmented riverine landscape. Additionally, barriers negatively impact population vital rates of riverine fishes that rely on connectivity between migratory routes to complete components of their life cycle, such as reproduction and recruitment. A capture-translocation strategy has been implemented for Razorback Suckers, Xyrauchen texanus, in the San Juan River to mitigate negative effects of barriers, while precluding nonnative species. Our goal was to use radio telemetry to assess movement behavior of Razorback Suckers following translocation above two barriers in the San Juan River. We deployed fixed remote radio receivers to determine residency time above each barrier and conducted mobile telemetry surveys to monitor upstream movements following translocation. Although individuals are likely to return downstream of a barrier within a year of translocation, we expected most individuals remained upstream long enough to successfully spawn. After translocation above the Piute Farms Waterfall, (PFW) 80% of individuals remained upstream for 26 days in 2020 and 23 days in 2021. Movement dynamics differed following translocation above the Public Company of New Mexico (PNM) weir, where 80% of individuals remained upstream for 37 days in 2021. At each barrier, we observed upstream movements ranging from 2 to 262 km and detected distinct aggregations within the expected spawning season. While translocation efforts may seasonally reconnect migratory routes for a proportion of the population, continued management and mitigation will be needed to improve the reproductive potential of this imperiled species.