Georgia
Influence of land-based activities on riverine delivery of contaminants
to estuaries
Principal Investigators: Aaron T. Fisk,University of Georgia; James T. Peterson,
University of Georgia; Gregg T. Tomy, Department of Fisheries and Oceans, Canada
ABSTRACT
There is still limited knowledge about the impact of the use and distribution of chemicals
being applied in modern society and produced as by-products of chemical and
manufacturing processes and energy production. These chemicals tend to accumulate
in, and are a concern for, aquatic ecosystems. The range of contaminants that have
been measured in US waters is extensive, and includes such diverse chemicals as
fluorinated stain guards to pesticides to personal care products. Such chemicals are of
particular concern in rivers, which drain urban, industrial, and agricultural regions, but
also the estuaries for which they drain into. As well, changes in stream-flow in rivers in
recent years due to low and high rainfall can influence in the input of freshwater and
associated contaminants into estuaries. Thus the potential contaminants found and their
levels in estuaries are thus likely to be highly influenced by the land-use within its
watershed and changes in stream-flow. Unfortunately, very little is known about the
types and concentrations of contaminants following into estuaries, particularly in the
southeast. Even less is understood about the impact of land-use and stream-flow on the
delivery of contaminants to estuaries. Estuaries, which are important and productive
ecosystems, are under increasing pressure from things such as land development,
climate change, and over-fishing. With increasing land development in the southeast
and along coastal zones there is a need to understand the threat posed by
anthropogenic chemicals.
This project will collect water in two major river systems in Georgia (Atlamaha and
Ogeechee Rivers) to identify and quantify organic contaminants. These rivers have very
different land-use patterns, both between and within the river systems. By collecting
samples in strategic locations on the rivers and use geographic information system
(GIS) data and models, we will identify the types and levels of contaminants associated
with land-use practices. Such information will be highly useful for the State of Georgia,
and interested citizens, so that best management plans (BMPs) for reducing the risk of
anthropogenic contaminants in estuarine systems can be developed. The methods used
in this project and the models developed are applicable to all rivers and estuaries and
will provide useful information and guidance for research and monitoring throughout the
US. This project will utilize state-of-art extraction methods and analytical instrumentation
to provide the most comprehensive examination of organic contaminants in Georgia
estuaries and their watersheds undertaken to date. This project represents the first step
in understanding the role that contaminants play in the health of estuaries