What's controlling pH in the Damariscotta River?

As climate change continues to alter marine ecosystems through temperature and salinity changes, acidification, and sea level rise, understanding how the estuaries and aquaculture may respond to these changes is critical to sustainable management. The Damariscotta River is the highest producer of oysters annually in Maine. Understanding this system is paramount to expand aquaculture throughout the state to meet the needs of a growing population and support coastal communities. We are developing a coupled hydrodynamic-biogeochemical model of the Damariscotta River that will focus on understanding why the Damariscotta River is such a productive oyster aquaculture area. The model will incorporate parameters such as temperature and salinity, nutrient sources, fresh water flow, primary productivity rates, chlorophyll a standing stock, uptake rates by oysters, proportion of food coming from detritus vs phytoplankton, benthic pelagic coupling and remineralization rates, bottom type, and bathymetry. Several questions of interest to be answered with the model include: What is the carrying capacity of the Damariscotta River for oysters? How does the composition of detritus in the river impact oyster growth rates, and what are the possibly implications due to shift in detritus composition? Increased temperature will likely increase oyster growth rates, will the oyster food supply increase proportionately? Will shelf intrusion of acidic water be of concern for the growing areas in the upper portions of the river? Will decreased pH due to increased freshwater runoff have an impact on growth rates?

Faculty Mentor: Damian Brady