Enhancing Beach Water Quality through Microbial Source Tracking-Based Interventions

Community Science/Research
Oral Presentation

Prepared by S. Esenther, M. Pascucilla
East Shore District Health Department, 688 E Main St, Branford, CT, 06405, United States


Contact Information: [email protected]; (203) 481-4233

ABSTRACT

Closure of recreational beaches is currently determined by simple fecal indicator bacteria thresholds. When water samples exceed these thresholds, closures are enacted, but this method does not offer insight into the source of contamination. While this approach streamlines the management process, it cannot identify the root causes of persistent contamination and guide targeted mitigation strategies in areas with consistently poor water quality. In this study, we demonstrate how microbial source tracking (MST) can be utilized to identify the origin of fecal bacteria from outfalls in Branford, Connecticut, discharging into the Long Island Sound near popular swimming beaches. Contrary to the assumption that failing sewage systems were behind the high contamination levels, our findings reveal that canine bacteria were responsible for the chronic bacteria contamination and resulting beach closures in this neighborhood. We describe the resultant public health campaign targeted to improve infrastructure and change community behavior, which successfully reduced canine-related contamination and led to zero beach closures during the 2024-2025 season. As climate change increases the frequency and severity of extreme rainfall events, coastal waters are expected to experience higher levels of bacterial contamination. The use of MST and other technologies will play an increasingly crucial role in monitoring recreational beach water quality and safeguarding public health in a changing climate.