Remote Sensing

We are in the process of completing a large-scale, state-wide assessment of intertidal shellfish resources using a high resolution aerial photography system complemented with on-the-ground surveys.  The assessment will photograph 8,550 km2 of coast at 0.25 m resolution.  Ground-truthing documents bed presence/absence, spacial coverage and bed quality. Helicopter overflights are used to supplement ground-truthing by photographing some of the state’s oyster flats which are not easily accessible.  Groundtruthing will allow scientists to interpret the aerial imagery to evaluate the oyster resource along the entire coast.  This updated information will be compared with historic data to determine resource trends and to optimize resource enhancement efforts.  Imagery and data will be shared through SCDNR’s ArcIMS clearinghouse. 

Shellfish Diseases

Two oyster diseases caused by protozoan pathogens (Dermo and MSX) have been responsible for widespread oyster deaths in many areas of the country. SCDNR monitors annually for the presence and intensity of these diseases. Because the severity of the diseases is usually worst in warm weather, sampling is conducted in the late summer or early fall. Both Dermo and MSX are present in South Carolina but have not been linked to any mortality events. Dermo is present in all SC oyster populations but the intensity of the disease is generally low compared to reports from other geographic areas. MSX is not present in all SC populations and the infections observed to date have been generally light. For more information please download our technical report

In 2004, we sampled six coastal sites across South Carolina to determine disease levels in oysters. Dermo infections were present at all six sites with infection levels varying throughout the state. MSX infections were not observed at the two northern sites in Georgetown County. At the four remaining sites in Charleston and Beaufort Counties, MSX infection levels ranged from 4% to 20%. Overall, MSX infection levels across SC were higher in 2004 when compared to 2003 where infections never exceeded 4%. We also examined oyster disease levels from one year old and three year old constructed reefs at five SCORE sites. Dermo was present in oysters at all SCORE sites, with mean disease levels highest in the three-year old (constructed in 2001) reefs. MSX infections were identified at four of the five SCORE sites.