South Carolina Sea Grant Consortium

A few times a year, volunteers fan out along the causeway that links the South Carolina mainland with the seashore community of Folly Beach to clean up plastic bottles, straws, bags, and other debris from along the road and the salt marsh. Some of this debris has come from cities miles away. On windy days, litter is often blown off city streets into waterways. During rainstorms, debris floats into drains that empty into rivers. Other trash probably came from places closer to home. “I see bags and other plastic flying off the beds of pickup trucks going down the causeway,” says Marty Morganello, who organizes the cleanups for the Charleston-area chapter of the nonprofit Surfrider Foundation. “I see them coming out the open windows of cars and out the backs of garbage trucks and even recycling trucks. This material is lightweight, and if you don’t secure it, it will fly away.” By one estimate, the volume of plastic debris going into the world’s oceans could more than double by 2025, assuming current trends in coastal development and plastics use. Some countries have begun identifying ways to improve management of plastic ... Beach cleanups yield enormous amounts of trash, with plastic items a major constituent.1 Although the human health impacts of this marine plastic pollution remain poorly characterized, it is widely seen as an emerging problem that deserves much more research attention.2 Likewise, there is a growing urgency among industry, government, nongovernmental organizations, and environmental groups to develop tools and policies to track, capture, and recycle plastic waste before it reaches the ocean.

Sediments and biota from 11 tidal creeks were sampled and classified into forested, suburban, and urban/industrial watershed land-use categories. Total PAH levels ( summation operatorPAH(16)) in sediments were significantly higher in urban/industrialized creeks (5,795 +/- 1,173 ng/g) compared to suburban (793 +/- 131 ng/g) and forested (238 +/- 34 ng/g) creeks. No differences in summation operatorPAH(16) levels among land-use classifications were found for either oligochaetes (Monopylephorus rubroniveus) or grass shrimp (Palaemonetes pugio). However, summation operatorPAH(16) levels in grass shrimp were related to sediment summation operatorPAH(16) levels and summation operatorPAH(16) levels in oligochaetes and grass shrimp eggs were related to impervious cover in the watershed. Diagnostic ratios suggest that the primary sources of PAH in suburban and urban/industrialized creeks are pyrogenic. Carcinogenic PAH contents of sediments and biota were related to impervious cover. While human exposures to these sediment-associated carcinogens were not assessed, levels of several carcinogenic PAHs in sediments of urban/industrial tidal creeks were above the levels that represent an increased cancer risk in humans.

Many coastal ecosystems are undergoing anthropogenic stress from large increases in population and urbanization. In many regions changes in freshwater and material inputs to the coastal zone are altering the biogeochemical and biological capacities of ecosystems. Despite increased watershed inputs, large tidal volumes and flushing indicative of macrotidal estuaries can modulate the fate of introduced materials masking some of the symptoms of eutrophication. The Land Use Coastal Ecosystem Study (LU-CES) examined linkages between land use and environmental properties of Malind and Okatee Creeks in South Carolina from 2001 to 2004. The objectives of this particular study were to assess the hydrography of the two macrotidal creek ecosystems, explore differences in dissolved oxygen (DO), and develop a better understanding of the variations in primary and benthic secondary production in southeastern creek ecosystems. Depth, pH, salinity, and DO were reduced and more variable in Malind Creek than in Okatee Creek, although both creeks had strong semidiurnal frequencies in salinity time signatures. While time series analyses of DO saturation in Malind Creek revealed a dominant semidiurnal pattern, Okatee Creek had a distinctly diel DO pattern. The strongly semidiurnal fluctuations in DO and reduced flushing time indicated that biological processes were not fast enough to influence DO in Malind Creek. The Okatee Creek system had a much greater storage volume, a wider marsh, and a dominant 25-h DO frequency. These attributes contributed to an estimated 8-10 times more phytoplankton-based carbon in Okatee Creek and twice the annual benthic production. As expected from their proximity to the upland, low surface area, and high organic content, both ecosystems were net heterotrophic. This fundamental understanding of tidal creek hydrography is being used to help define linkages among differential watershed land uses, flushing characteristics, and levels of biological production in coastal ecosystems of the southeastern United States.

The Southeast Coastal Ocean Observing Regional Association (SECOORA) is maturing into an organization that can effectively coordinate the development and evolution of a comprehensive coastal ocean observing program for the Southeast U.S. Strategies are being developed to productively integrate the existing base of legacy assets (including observation systems and platforms, data analysis and management centers, research efforts, educational initiatives, and personnel) and the wide spectrum of current and potential stakeholders. There are many direct and indirect applications of the data and information derived from coastal ocean observing systems, and the issues related to coastal natural hazards are of particular interest in the southeastern U.S. Risks to life, property, and natural resources from natural hazard events will increase due to the projected increase in storm frequency and intensity and growth of the region's coastal population over the next several decades. Unprecedented hurricane damage and human despair that resulted from the 2005 hurricane season has tested government response at all levels, revealing unanswered questions regarding the level of our preparedness to deal with and respond to disasters of this magnitude. SECOORA provides a regional coordination and planning mechanism by which coastal inundation forecasting and mitigation efforts can be initiated and addressed through collaborative efforts in the Southeast U.S. among its sub-regional observing systems and their numerical modeling and data management capabilities.