South Carolina Sea Grant

A large percentage of South Carolina’s
economy is driven by the popularity of beaches as tourist destinations.  Hypoxic (low-oxygen) conditions have been
documented in the nearshore coastal waters of Long Bay, South Carolina, during
summer months over the past several years. 
To maintain a healthy environment for recreation it is necessary to
assess the impacts of land use on groundwater discharge to the area.  Researchers measured radon activities of
shallow beachface groundwater and nearshore bottom waters to estimate mixing
rates and submarine groundwater discharge in Long Bay.  They successfully developed a mixing model
based on these measurements, which helped determine that natural phenomena such
as limited mixing and submarine groundwater discharge (both previously
overlooked) can significantly influence nearshore water quality and lead to
hypoxic conditions.  This model can be
applied to other types of marine environments to help determine the causes of
hypoxia, and as such could be a valuable tool in maintaining coastal water
quality, especially in highly developed (urban) areas.