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Graduate Research Fellowship
Metals contamination in the Apalachicola River and estuary

Debra Harrington
Graduate Research Fellow 1997-1999
Apalachicola, FL
Florida State University

Assessment of a watershed's environmental quality should include a combination of biomonitoring techniques and hydrochemical analysis. Metal concentrations associated with transport phases such as bioavailable, dissolved, colloidal and particulate phases can be correlated to representative organisms at various trophic levels. Hydrological variations during storms provide a significant transport mechanism for toxic metals from uplands and flood plains. Agricultural practices, urbanization and industrial development in uplands can lead to extreme changes in the hydrochemical response of the watershed during storms. Research has indicated that toxic metals, commonly originating from these sources are a significant precursor to ecosystem deterioration. Acute or chronic exposure to toxic metals with water quality fluctuations, can impact sensitive species that occupy essential positions in the food web. The mobilization and transport of toxic metals threaten both local and regional ecosystems. The Apalachicola Bay system includes a 19,200-km2 drainage area flowing from Georgia, Alabama and Florida. The Apalachicola National Estuarine Research Reserve comprises the lower portion and receives massive influxes of sediment from the Apalachicola River system. In recent years, observations of ecological stress include fish kills that possibly originated off-shore.

The purpose of this study is to investigate seasonal variation in toxic metal concentrations during baseflow and stormflow in the estuary and the impact to representative organisms in the ecosystem. The proposed study differs from previous research on metals in the estuary, as it includes a comprehensive reliable sampling protocol and sites that are known hot spots. The protocol and procedures used for this study employs and expands on those developed by the author to conduct research in the Mid-Atlantic region. The metal analysis will be conducted on an ICP-MS instrument that can quantify trace metals at low detection limits. Monitoring toxic metals in the Apalachicola estuary and surrounding wetlands will help to identify present and potential influences on the ecosystem's deterioration. The data is submitted to an intensive statistical analysis to indicate significant correlations between metal concentrations and ecological assessments. Expected outcomes of this research will be: the identification of sources of metal loading, enhanced understanding of high flow events on the transport of metals, and practical assistance to managers seeking to prevent further ecosystem deterioration.
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