Water Resources Research Act Program

Details for Project ID 2020ME229B

Data-driven support for adaptive pollution-based closure decisions in shellfish growing areas of Maine

Institute: Maine
Year Established: 2020 Start Date: 2020-03-01 End Date: 2021-02-28
Total Federal Funds: $36,000 Total Non-Federal Funds: $49,725

Principal Investigators: Dr. Samuel Roy

Abstract: There are major public health issues associated with fecal borne pathogens entering shellfish growing areas (SGAs) across the Maine coast (DMR 2012). Storm runoff can mobilize pathogens from sources such as leaking septic systems, combined sewer overflows, and overboard discharge sites into coastal waters. The Maine Department of Marine Resources Bureau of Public Health (DMR) oversees the application of the National Shellfish Sanitation Program (DHHS 2015) and has established statewide harvest closure rules based on observed links between heavy rainstorms and coastal pollution. This statewide rule takes a precautionary approach to prevent harvesting of storm-polluted shellfish based on daily rainfall exceeding 2 inches, or 1 inch in particularly sensitive locations. However, this approach can produce unnecessary closures in locations where pollution problems have not occurred. Storm patterns may not predictably trigger regional or statewide pollution because the intensity of rainfall, storm runoff, pollution sources, and tidal mixing exhibit substantial spatial variability across Maine (even at very local scales), and there are many other human and environmental drivers that can influence pollution trends. Wild and aquaculture shellfish harvests recently accounted for ~$56M of Maine’s coastal economy, thousands of local jobs, and a cherished way of life (Athearn 2008). Storm-related pollution poses significant and poorly anticipated threats to public health with real economic and cultural consequences (Mallin et al. 2009, Leight et al. 2016). DMR seeks to reduce unnecessary closures and promote greater economic potential while remaining compliant with national sanitation standards. We are building a comprehensive collaboration with DMR and commercial partners, including Hollander & de Köning mussel aquaculture and Waukeag Neck Oyster Company to analyze the storm-pollution link, expand the analysis to include more potential drivers of pollution, and provide improved, location-specific decision support for pollution-based harvest regulation. The intent of this collaboration is to reduce unnecessary closures and allow for safe re-openings sooner after closures with no added risk to public health. Our approach integrates stakeholder engagement, spatial data analytics, and workforce development for students. Decision support will be based on observed linkages between coastal water quality, measured as fecal coliform (FC) scores, and human (septic systems, overboard discharge sites, combined sewer overflows, wastewater treatment plant outfalls) and environmental (precipitation, runoff, tides, temperature, salinity, season) drivers governing SGA pollution source, delivery, and residence time.