Abundance, Diversity, and Potential Contamination Sources of Enterococci in Creeks

Abstract

Enterococci in creeks were evaluated with respect to temporal and spatial variation, potential sources, abundance, and diversity in surface water and sediments at eight locations under four temporal conditions. With the exception of one location, Enterococci concentrations exceeded the USEPA recommended level for impaired watershed, suggesting the crucial role of creek water in governing water quality in the environment. Moreover, effective storm water management is critical in maintaining water quality because concentrations of Enterococci in the surface water during highflow were approximately 100 times of those sampled during baseflow. Sediment could serve as a reservoir of Enterococci for the water system, evidenced by their high levels in sediments. Of 702 isolates evaluated, six Enterococcus species were found with Ent. feacalis being most dominant. The less dominant species such as Ent. hirae, Ent. avium, and Ent. dispar may be more useful in microbial source tracking for the watershed evaluated.