Spatial changes in trace element water chemistry across Piedmont rivers of Georgia with applications for native fish species conservation

Anthropogenic changes to freshwater river systems have impacted native fish and mussel distribution and abundance. Disruptions in movement and migration have led to the declines of many important species in Georgia, including several threatened and endangered species. Furthermore, anthropogenic barriers, physical stream alterations, and reservoir construction may facilitate invasive species expansion and colonization, thereby impacting native species through displacement, disease, and hybridization. The impacts of these human activities – and their relative degrees of influence – vary among river basins and among distinct segments within systems. To help assess the impacts anthropogenic effects have on native species, fish microchemistry can be used to help decipher large scale movement patterns, natal origins and introductions, and habitat use. Trace elements, such as strontium and barium are incorporated into calcified structures of fishes relative to water concentrations. Therefore, quantifying trace element concentrations within and among river systems is a conduit for examining fish behaviors, such as movement and dispersal. The Piedmont ecoregion is an ideal place to study microchemistry as it has unique geologic features and human population centers that can influence water chemistry. Furthermore, there is a diverse fish assemblage containing a mix of native species in need of conservation and introduced or invasive fishes.

Research sponsored by the USGS/NIWR Water Resources Act Program 104b Grant (Fiscal Year 2023-2024)

Report Title

Spatial changes in trace element water chemistry across Piedmont rivers of Georgia with applications for native fish species conservation

Principal Investigator(s)/Authors and Affiliation

Dr. Martin Hamel
University of Georgia, Associate Professor

Dr. James Shelton
University of Georgia, Associate Professor

Abstract

Anthropogenic changes to freshwater river systems have impacted native fish and mussel distribution and abundance. Disruptions in movement and migration have led to the declines of many important species in Georgia, including several threatened and endangered species. Furthermore, anthropogenic barriers, physical stream alterations, and reservoir construction may facilitate invasive species expansion and colonization, thereby impacting native species through displacement, disease, and hybridization. The impacts of these human activities – and their relative degrees of influence – vary among river basins and among distinct segments within systems. To help assess the impacts anthropogenic effects have on native species, fish microchemistry can be used to help decipher large scale movement patterns, natal origins and introductions, and habitat use. Trace elements, such as strontium and barium are incorporated into calcified structures of fishes relative to water concentrations. Therefore, quantifying trace element concentrations within and among river systems is a conduit for examining fish behaviors, such as movement and dispersal. The Piedmont ecoregion is an ideal place to study microchemistry as it has unique geologic features and human population centers that can influence water chemistry. Furthermore, there is a diverse fish assemblage containing a mix of native species in need of conservation and introduced or invasive fishes.

The objective of our study is to develop a comprehensive data set of environmental levels of trace elements among major river systems and their tributaries in the Piedmont region of Georgia. Assessments of water chemistry throughout a network of rivers in the Piedmont ecoregion will provide a baseline for future changes in water chemistry due to land use changes resulting from urbanization, agriculture, or other sources of change, and a mechanism for understanding fish movement dynamics.

Report

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