Modeling the presence of mercury in the aquatic environment: a focus on South Carolina. (South Carolina Academy of Sciences Abstracts).
In South Carolina, elemental mercury has accumulated in the aquatic
environment via atmospheric deposition. Through methylation, elemental
mercury is converted to methylmercury and absorbed by aquatic biota.
Biomagnifying up the food chain, mercury is concentrated in high
tropic-level fish and is consumed by humans. Since 1993, the South
Carolina Department of Health and Environmental Control has been
sampling fish throughout the state for their mercury content. This data
provides the opportunity to model the spatial distribution of mercury in
the aquatic environment of South Carolina. The mercury to methylmercury
conversion is space-specific and is higher in areas with high organic
content in soil, reducing conditions, soil environments. Because these
environments can be spatially explicit, it is possible to use a
Geographic Information System to model where these conditions exist.
Through the availability of site-specific fish-tissue data and the
locations of methylating conditions on the landscape, a relationship
between these two variables is deduced through regression. This
predictive model reveals the probable concentration of mercury in
fish-tissue in areas where sampling has not been conducted. This model
allows for fish-consumption warnings to be issued in South Carolina
areas where sampling is not economically or environmentally possible.
Tara M. Koman
Department of Geography
University of South Carolina