Cooperative Fish and Wildlife Research Units Program: Utah
Education, Research and Technical Assistance for Managing Our Natural Resources

Utah Project

BoR: Understanding and quantifying potential movement patterns of Rio Grande Silvery Minnow in the Middle Rio Grande, New Mexico

May 2018 - January 2023


Participating Agencies

  • Bureau of Recalmation
Ben Stout holding a Rio Grande Silvery Minnow.

The Rio Grande Silvery Minnow (RGSM, Hybognathus amarus) is listed as endangered under the ESA and remains critically imperiled in the Middle Rio Grande River. Although there is existing information on their basic habitat and life histories, there are many critical data gaps. These pelagic spawners release semi-buoyant eggs in the water column and rely on floodplain connectivity for rearing, after drifting downstream and being retained in available habitats. Habitat alteration, loss of inundated floodplains, and alteration and dampening of the hydrograph have negatively impacted the species through reduction in floodplain connectivity, and in the absence of floodplain connectivity, the eggs drift further causing upstream persistence of the species to become reliant on the ability of these fish to move upstream to recolonize areas above. This project aims to describe and quantify the ability to move and drivers of RGSM movement in its contemporary fragmented habitat. To do this, we are releasing PIT-tagged RGSM into the Middle Rio Grande River and tracking their movement during differing environmental conditions and seasons with a combination of stationary and mobile PIT-tag antennas. The project is a collaboration of researchers across multiple agencies and includes the U.S. Bureau of Reclamation and U.S. Fish and Wildlife Service. Our project will inform the design and implementation of future modifications to dams in the Middle Rio Grande aimed at allowing fish movement in the upstream direction in particular.

Research Publications Publication Date
Stout, J.B, M.M. Conner, P. Budy, P. Mackinnon, and M. McKinstry. 2019. We ain’t afraid of no ghosts: Tracking habitat interactions and movement dynamics of ghost tags under differing flow conditions in a sand bed river. 21 September, 2019 Accepted. North American Journal of Fisheries Management, Management Brief 39:1337-1347 September 2019
Stout, J.B., M.M. Conner, P. Budy, P. Mackinnon, and M. McKinstry. 2020. Keeping it classy: Classification of live fish and ghost PIT tags detected with a mobile PIT tag interrogation system using an innovative analytical approach. Canadian Journal of Fisheries and Aquatic Sciences 77:1564-1573. | Abstract June 2020