Evaluation of microbiological water quality in Point Judith Pond (Rhode Island, USA): Quantitation of fecal pollution and presence of human pathogenic bacteria

Abstract

Water and sediment samples were collected in the Bluff Hill Cove area of Point Judith Pond from 12 stations along three parallel transects, and eelgrass samples were taken at two sites per transect. Fecal enterococci (FE) in the water samples exceeded USEPA regulatory limit of 100 MPN/100 mL for safe recreational and shellfish harvesting use in 24 out of 41 samples. Sediment samples had the lowest FE counts, whereas eelgrass had the highest counts. Using qPCR, H. pylori was detected in 8 out of 41 samples, but E. coli O157:H7 was not detected. Overall, higher levels of H. pylori were detected in 33% of the eelgrass samples and 33% of the sediment samples as compared to 9% in the water column. Microbial source tracking, using the Bacteroides marker HF183, indicated the presence of human fecal bacteria in 7 out of 41 samples, four of which were positive for H. pylori.