32 Hydrogeology

Added due to amount of discipline abstracts submitted.

Tuesday, 10 March 2026
1:30 PM - 5:30 PM
RCC, 106

“In Hot Water”: Assessing Climate Change Impacts to Critical Habitat for Alabama’s Imperiled Fish Species

Paper number: 32-13
Program: Technical Sessions
Time: 4:45 PM – 5:00 PM

Authors

Abstract

Aquatic species face imperilment and are experiencing rapid rates of extinction at a disproportionate rate compared to terrestrial organisms. For aquatic organisms, diverse and dynamic hydrogeological processes as well as anthropogenic stressors are known to influence the suitability of local habitats over short and long timescales, often restricting species distributions. Now, fisheries biologists have been tasked with determining how those local conditions are impacted by the broader and uncertain influence of habitat alteration caused by climate change.

Four of Alabama’s federally listed freshwater fish species are currently found in areas that are reliant on groundwater-surface water interactions and the resulting local habitat conditions to complete life history requirements, including a limited range of water temperature and dissolved oxygen values. Although these species have persisted in the face of significant anthropogenic changes due to natural hydrologic characteristics that buffer habitat temperatures and dissolved oxygen values, potential changes to these water properties from climate change may threaten the current groundwater-surface refugia that these species rely upon, thereby compromising species survival.

To assess the severity of these potential impacts, Geological Survey of Alabama researchers combined long-term climatic models with a correlation and trend analysis of U.S. Geological Survey stream gage data from various sites throughout Alabama. A strong positive relationship between maximum air temperature and maximum water temperature was found, as was a strong negative relationship between water temperature and dissolved oxygen values. Additionally, an analysis of riverine heatwave occurrence (five or more consecutive days of maximum water temperature exceeding the seasonal 90th percentile threshold) revealed that some heatwaves were unique to individual watersheds, while other heatwaves occurred concurrently.

This scenario has the potential to significantly impact the local habitat conditions required by these imperiled fish, conceivably resulting in habitat modifications or loss, most critically in shallow headwater stream environments that are more vulnerable to changes in temperature and dissolved oxygen values related to diminished water volume.

Combining long-term climatic modeling with local habitat monitoring increases our understanding of the effect of altered hydrology and water properties on habitat suitability and species resilience and aids in creating risk assessments that incorporate multiple anthropogenic stressors and natural system controls. This multidisciplinary approach will help protect and enhance these fragmented habitats and better inform species recovery plans.

Geological Society of America Abstracts with Programs. Vol. 58, No. 1

doi: 10.1130/abs/2026SE-411601

© Copyright 2026 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.