Geographic information systems (GIS) and kriging: Analysis of the spatial and temporal distributions of the oyster pathogen Perkinsus marinus in a developed and an undeveloped estuary

Infection and prevalence of Perkinsus marinus (Dermo), a common protozoan p athogen of the oyster (Crassostrea virginica), are commonly correlated with temperature and salinity. However, these factors do not account for all in fection variability. Other factors such as watershed dynamics or anthropoge nic disturbances may play a role. Geographic Information System (GIS) techn ology applying land use and anthropogenic activity was used to document Der mo infections in two South Carolina coastal estuaries. Kriging analysis was used to calculate disease prevalence from sample sites to the estuary as a whole. Results indicate that land use patterns may affect the distribution of the disease.