Concurrent Session H. Understanding and Managing Land-Sea Connections Along the Maine Coast

Afternoon session

* 2 Training Contact Hours are available for this session.
* 2 AICP CM credits are available for this session.

The focus of this session is on development and use of research and monitoring information to make management and regulatory decisions in coastal estuaries and the watersheds draining freshwater flows to them. This session seeks to bring together researchers and practitioners from academic, governmental, and non-governmental institutions to focus on the dynamics of the coupled systems and issues such as nonpoint source runoff, climate change, and management responses to pollution and habitat problems affecting coastal communities. Special attention will be given to project examples demonstrating strategies used to formulate stakeholder-engaged solutions to problems affecting coastal watershed-estuary systems.

Session Co-chairs:
Sean Smith
Earth & Climate Sciences and Mitchell Center for Sustainability Solutions, UMaine

Bridie McGreavy
Communication & Journalism and Mitchell Center for Sustainability Solutions, UMaine


1:30pm – 1:55pm

Microbial source tracking as a tool for managing coastal water pollution issues

Derek Rothenheber (student), University of New Hampshire;
Meagan Sims, Maine Healthy Beaches


Each year more than 30 million people visit Maine, particularly the southern counties of York and Cumberland and their popular coastal beaches. Monitoring these recreational waters to ensure public health and safety is critical to sustaining Maine’s economy, as tourism is one of the greatest contributors. Traditional fecal pollution source tracking approaches have primarily consisted of enumerating fecal indicator bacteria (E. coli, enterococci, etc.) in a targeted sampling/sanitary survey approach. However, these methods are limited because they are unable to discern host source(s) of fecal contamination. To address this issue, we have adopted microbial source tracking (MST) assays to identify fecal sources (mammals, humans, birds, gulls, dogs, and ruminants) present in coastal waters, as well as assays to quantify the relative strength of three source types (mammals, humans, and birds). Current results allow for identifying predominate fecal source(s), tracking seasonal patterns, determining actual pollution sources, and assessing the relative differences in the strength and significance of identified fecal sources in coastal water across the Northeast. To address ongoing fecal contamination in the Goosefare Brook, the University of New Hampshire partnered with the Maine Healthy Beaches Program to integrate MST into ongoing pollution source tracking work. The addition of MST to identify and quantify fecal sources adds an additional layer of information when addressing water quality issues, by improving decision making for posting beach advisories and helping with the prioritization of fecal source elimination strategies and better resource management.

2:00pm – 2:25pm

Intensive Sampling During Storm Events to Identify Land-based Sources of Fecal Contamination to a Coastal Estuary

Lauren Bizzari, FB Environmental Associates;
Margaret Burns, FB Environmental Associates;


Throughout New England, coastal communities are grappling with how to better identify and manage sources of nonpoint source pollution, specifically with respect to fecal contamination and associated fecal indicator bacteria (FIB). Connections between land and sea are particularly evident during storm events, when drainages that are typically dry under normal conditions become activated. Monitoring programs usually conduct grab sampling during wet and dry weather events. However, low thresholds ( >0.1” within 24 hours) limit our understanding of larger storm events when FIB are mobilized. Additionally, these conditions provide little information on changes in the transport, concentration, and source of FIB to estuaries along the hydrograph. In November 2016, we monitored FIB and nitrate (as a co-indicator of human waste) across two storm events in Parsons Creek, Rye, NH, one of many coastal estuaries impaired by elevated fecal pollution. Overall, the higher-magnitude storm saw significantly higher exceedances (81%) of the instantaneous criterion for New Hampshire (104 col/100ml) than the lower-magnitude storm (38%). Human fecal contamination, possibly from flooded low-lying septic systems, was indicated by high nitrate and bacteria concentrations at several sites. Additionally, continuous relative depth measurements revealed a significant lag (1 to 2 hours) between dead low tide in the Creek compared to a local tide station (Hampton Harbor) as a result of tidal restrictions (e.g. undersized culverts). This study emphasizes the importance of timing during event sampling for bacteria in coastal systems and provides a mechanistic framework for monitoring nonpoint source pollution in other coastal communities across New England.

2:30pm – 3:00pm
Afternoon Break

3:00pm – 3:25pm

A runoff-based vulnerability analysis to examine and communicate the dynamics of bacteria pollution events in the Gulf of Maine

Sam Roy, Senator George J. Mitchell Center for Sustainability Solutions, University of Maine;


The culture and economy of coastal Maine is closely linked to near shore water quality. Besides its obvious impacts on health, bacterial pollution in estuaries and beaches has major negative impacts on the multi-million dollar tourism and shellfishing industries in the state. Local stakeholder groups recognize the need for a decision support system that would provide better informed regulations for coastal watershed management. The New England Sustainability Consortium is an interdisciplinary NSF EPSCoR funded project organized to strengthen the connection between science and decision-making through the practice of sustainability science. Our objectives are to 1) improve contamination event predictions based on quantitative model scenarios, 2) improve lines of communication between stakeholders and researchers, and 3) provide a workable solution on issues of health and lost revenue.

We use a combined statistical approach to identify watershed and estuary characteristics that are linked to higher vulnerability. Hydraulic flow and marine mixing models are used to determine delivery from watershed to coast and contaminant dilution in the estuary. By combining our statistical model results with salinity and fecal coliform count data, we find that the primary trigger for high levels of bacterial contamination are population density, while metrics that describe the delivery and residence time of water have a secondary influence. Results from our hydraulic models suggest that current regional closure regulations can overestimate the time interval of contamination for some watersheds, and new regulations based on quantitative models and local observations would provide greater economic stability without presenting a significant health risk.

3:30pm – 3:55pm

How to Sustain New England’s Tidal Marshes in the Face of Sea Level Rise? A Case Study of Action-oriented Knowledge Sharing among Scientists, Managers, and Stakeholders

Peter H. Taylor, Waterview Consulting;


An initiative sponsored by the Northeast Regional Ocean Council (NROC) in 2014-15 provides a model for knowledge sharing on a priority management issue when scientific understanding is emerging and rapidly changing. Tidal marshes provide high ecological value and diverse ecosystem services. However, they are extremely vulnerable to projected rapid sea level rise. One way that some tidal marshes may be able to survive is through their natural ability to “migrate” landward as the sea rises. Managers and stakeholders seek to take actions that would support tidal marsh migration, working at geographic scales from individual marshes to the Northeast region. However, marsh migration is a complex phenomenon, and scientific understanding is advancing quickly. NROC saw an immediate need to build linkages between the scientific and management realms, so that management outcomes will be as effective as possible. We collaborated with NROC and a multi-agency steering committee to facilitate knowledge sharing regarding best practices for using marsh ecosystem models to inform management and policy. Through interviews with scientific and management experts from government, academic, and non-government entities, a literature review, and a regional workshop, we developed a guidance document: Make Way for Marshes: Guidance on Using Models of Tidal Marsh Migration to Support Community Resilience to Sea Level Rise ( The visually engaging and reader-friendly guide covers the lifecycle from scoping out a modeling approach to communicating results effectively for decision-making. The process of developing the guide strengthened an interdisciplinary community of practice and offers valuable lessons for similar knowledge-sharing efforts.