Document Type

Technical Report

Publication Date



geographic information systems, water quality monitoring, pollution


There have been concerns about mercury (Hg) contamination in fish in Arkansas since the discovery of the problem in the Ouachita River in 1992 (Armstrong et aI., 1995). Of the more than 170 lakes and streams sampled by the Mercury Task Force from 1992 through 1994, 23% had fish with Hg concentrations exceeding the FDA Action Level of 1 ppm (Armstrong et aI., 1995). Cause of the fish Hg contamination, however, is unknown. Given the economic, human-health and environmental costs associated with fish Hg contamination, it is critical that the cause of this widely-spread problem be identified. Determination of the cause will lead to an improved management and an effective remediation of the problem. The objective of this study was to investigate the cause of fish Hg contamination in Arkan as through spatial analysis of environmental factors and the locations where fish tissue Hg concentrations have been determined using a Geographic Information System (GIS). The computer software known as Geographic Resources Analysis Support System (GRASS) was used in this study to examine the spatial correlations between fish Hg contamination ann soils, geology, vegetation, topography, and those environmental factors that may favor Hg methylation.

Report Number