Community Update

Water quality in Damariscotta Estuary

Tue, 01/27/2015 - 12:15pm

    Twenty-five municipal officials, citizen volunteers, Damariscotta River Association (DRA) board members, and other interested citizens gathered at the DRA Jan. 8 to learn about the Damariscotta Estuary, its water quality and overall condition.

    The speakers were Drs. Larry Mayer and Damian Brady of the University of Maine Darling Marine Center.

    DRA Director of Education and Environmental Monitoring Sarah Gladu opened the evening with a description of DRA estuary monitoring efforts over the past two years.

    “The citizen volunteers gather dissolved oxygen, salinity, temperature and transparency data at seven locations in the estuary twice a month May through October,” Gladu said. “They also take water samples which are analyzed for total nitrogen at the Darling Marine Center.”

    This data, she continued, will be used to inform the community about the health of the estuary over time, provide guidance to municipal policy and inform landowners of best practices to minimize impact of land-based activities on the estuary, building on more than 25 years of DRA volunteer water quality monitoring.

    Dr. Larry Mayer reviewed the water quality conditions as indicated by the DRA volunteers' data, comparing them with measurements from university classes and researchers. He addressed the question of whether the estuary is healthy or not, noting that most data indicate a reasonably unpolluted and productive body of water.

    However, the frequent sampling enabled by the citizen monitoring showed times and places that are worth watching for future environmental changes. In particular, high rainfall events or nutrient inputs may lead to ocean acidification in the upper estuary.

    Dr. Damian Brady provided historical perspective through his presentation which utilized data from Dr. Bernie McAlice from 1968 through 1977.

    Brady focused on temperature change in several of his slides which depicted the clear increase of temperature over recent decades. He also discussed the link between temperature changes of a few degrees and how this impacts certain animals such as short-nosed sturgeon, a species that have historically been found in the Damariscotta estuary.

    Brady showed the audience graphs from McAlice’s work compared to recent monitoring by Dr. Mary Jane Perry, Director of the Darling Marine Center. These graphs depicted dramatic temporal changes in phytoplankton blooms.

    Phytoplankton are the single-celled plants that form the basis of the marine food web.

    Both scientists agreed that DRA sampling provides invaluable data and that gathering this water quality data should continue even as additional automated measuring devices are deployed.

    According to Gladu, DRA intends to continue volunteer water monitoring while also providing leadership for a new coast-wide coalition of water quality monitoring groups called Maine Coast Observing Alliance.

    Visitors are welcome at the Great Salt Bay Heritage Center in Damariscotta as well as the many other DRA properties throughout the region.

    There a number of volunteer opportunities and a volunteer application can be requested from the DRA.

    For more information, call 207-563-1393, email, or visit