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

Texas Project

Development of Pecos assiminea (Assiminea pecos) monitoring methods and effects of habitat restoration on Pecos assiminea at Bitter Lake National Wildlife Refuge

January 2013 - September 2015


Participating Agencies

  • USGS - SSP

Pecos assiminea Assiminea pecos is a tiny (< 2.1 mm) snail with a distribution limited to Chaves County, New Mexico and Pecos County, Texas. The species has been federally listed as endangered since 2005. Bitter Lakes National Wildlife Refuge is one of the few strongholds of Pecos assiminea, but knowledge of its distribution and habitat use remains incomplete. Furthermore without viable survey techniques, the status of the species and the impacts of habitat restoration activities cannot be determined. The recovery plan for Pecos assiminea calls for developing a technique to monitor its abundance, thus our primary and secondary objectives are to evaluate two surveying techniques, quadrat and wood tile sampling, for determining Pecos assiminea distribution, density, and habitat associations and to evaluate the effect of common reed removal on a suite of endangered species including Pecos assiminea, two springsnails and an amphipod (Pyrgulopsis roswellensis, Juturnia kosteri, Gammarus desparatus, respectively).

Research Publications Publication Date
Roesler EL, & TB Grabowski. 2018. Estimating factors influencing the detection probability of semi-aquatic freshwater snails using quadrat survey methods. Hydrobiologia 808:153-161. doi: 10.1007/s10750-017-3415-9 | Abstract February 2018
Theses and Dissertations Publication Date
Roesler EL. 2016. Development of habitat use data, detection, and survey methods for the endangered gastropod, Pecos assiminea (Assiminea pecos) at Bitter Lake National Wildlife Refuge. MS thesis. Texas Tech University, Lubbock, Texas May 2016