Abstract
Bays, estuaries, and rivers provide vital ecological, economical, and recreational services to coastal communities. These vital water bodies are under increasing pressures from urbanization, land-use changes, population growth, a changing climate, sea-level rise, and extreme weather events. Closures of shellfish harvesting (and recreational) coastal and inland waters are most often due to fecal contamination. Fecal indicator bacteria (FIB) can come from many sources; leaking sanitary sewers, pets, livestock, wildlife, and birds. Understanding the origin (source) of fecal pollution at locations where shellfish are grown is essential in assessing the associated human health risks as well as the determining actions required to manage shellfish harvesting areas. Regulatory methods for monitoring fecal contamination cannot differentiate between human and non-human fecal sources. Management and mitigation of fecal pollution entering shellfish waters would be more cost-effective if species-specific identification of the sources of fecal contamination were possible. To help address this gap, DNA-based genetic fingerprinting methods, collectively referred to as Microbial Source Tracking (MST) are gaining use, particularly as tools to supplement watershed assessments. Although MST-based studies have focused on beach and recreational waters, fewer have addressed their applicability for assessing shellfish growing areas. The overall objective of this project is to identify the species-specific source(s) of fecal contamination impairing shellfish harvesting waters in the Fowl River Bay area. Our experimental approach is to apply DNA-based source tracking methods using species-specific FIB markers for human, avian, ruminant, and domestic animal fecal bacteria present in water samples collected from designated shellfish harvesting locations in the Fowl River Bay. During this presentation, preliminary data for the applicability of a set of species-specific DNA markers for shellfish harvesting waters will be discussed.
