Date of Award

Winter 2011

Project Type


Program or Major

Natural Resources

Degree Name

Master of Science

First Advisor

Stephen H Jones


Escherichia coli ribotyping was used to identify fecal contamination sources in Grommet Creek- a tidal creek that drains into Great Bay and contaminates shellfishing beds. Water samples were collected during late summer through late fall. Fecal samples were collected to establish a local source species database. Fecal indicator bacteria were enumerated from water samples and ribotyping was conducted by using EcoR1 restriction enzyme digestion and an automated RiboPrinter(c). There was consistent relative abundance between source types with wild animals and birds as the primary sources. An optimized approach for maximizing source identification involved using a 90% similarity threshold and prioritizing the first (local) database, then the second (larger area), and the third (regional) database for source identification. Using this approach, 67% of the E. coli water sample isolates were identified to sources, mainly as geese, deer, and fox, suggesting that diminishing of these sources could improve water quality.