Monitoring and mapping non-native crayfish in the lower Colorado River System (Arizona and New Mexico)

Timeline: 2021-2023
Collaborators: Tony Javiya (UTSA), Jen Smith (UTSA), Jeff Sorensen (AZGFD)
Funded by: United States Fish and Wildlife Service
Overview: Objectives of this research are to (1) perform presence-absence surveys of non-native virile crayfish (Faxonius virilis) and (2) use in situ data loggers to monitor temperature/flow intermittency at 108 sites in the lower Colorado River basin. We are using these field-based data to develop occupancy models and species distribution models with the goal of understanding niche dimensions of crayfish and mapping habitat suitability across ~ 60,000 confluence-to-confluence stream reaches. This research will develop tools (e.g., GIS layers) to inform management decisions (e.g., prioritizing eradication efforts). Ultimately, this work will help to conserve the unique and imperiled fauna of invertebrates, fishes, and herps in the Desert Southwest.



Sabino Creek, Arizona, one of 108 survey locations in the lower Colorado River basin. Photo credit: Matt Troia

A virile crayfish (Faxonius virilis). Photo credit: Jen Smith

Habitat use and population dynamics of Guadalupe bass in the Mission Reach, San Antonio, Texas

Timeline: 2021-2022
Collaborators: Mary Finucane (UTSA), Randy Myers (UTSA), Gordon Linam (UTSA), Shawn Donovan (SARA)
Funded by: Texas Parks and Wildlife Department
Overview: This research has two objectives focused on Guadalupe bass (Micropterus treculii) and largemouth bass (M. salmoides) in the Mission Reach of the San Antonio River: (1) Quantify/compare habitat associations of the two species; and (2) Characterize population size structure and estimate abundance of each species. These data will inform management of this unique urban population of Guadalupe bass, which was re-established in 2015 by TPWD following restoration of the stream channel and riparian zone of the Mission Reach by the City of San Antonio.


A Guadalupe bass captured during July 2021 survey of the Mission Reach. Photo credit: Matt Troia


UTSA students and TPWD collaborators conducting a boat electrofishing survey on the Mission Reach in July 2021. Photo credit: Matt Troia

Thermal sensitivity and exposure of spring-associated fishes in South Texas

Timeline: 2022-2025
Collaborators: Nick Loveland/Garrett Tucker (UTSA), Warren Schlechte (TPWD), Sarah Robertson (TPWD), Marty Kelly (TPWD), David Young (TPWD)
Funded by: Texas Park and Wildlife Department
Overview: This research will use (1) lab-based physiology experiments to characterize thermal sensitivity of spring-associated fishes and field-based monitoring of stream temperature regimes to characterize thermal exposure. Focal species include: the Guadalupe bass (Micropterus treculii), Guadalupe roundnose minnow (Dionda nigrotaeniata), Devils River minnow (D. diaboli), Rio Grande darter (Etheostoma grahami), and plateau shiner (Cyprinella lepida). Monitoring will take place in San Felipe and Pinto Creeks in south Texas and numerous streams draining the Edwards Plateau. By integrating sensitivity and exposure data, we will produce a comprehensive view of spatially-explicit and species-specific vulnerability to warming. This information will inform conservation actions to mitigate climate change, land use change, and groundwater management.


The Guadalupe River. One of many Hill Country streams we'll be studying beginning spring of 2022. Photo credit: Matt Troia


San Felipe Creek in Del Rio, Texas is a designated Critical Habitat for the Federally Threatened Devils River Minnow (Dionda diaboli). We'll be deploying temperature loggers to monitor temperature regimes in this spring-fed stream beginning in 2022. Photo credit: Matt Troia