Seasonal Estuary Water Quality Monitoring Underway
The midcoast Maine way of life, including the economy, recreation, and culture, relies on our world-class coastal waters; yet our estuaries, rivers, and bays are under increasing threats from warming waters, acidification, and pollution. The Maine Coastal Observing Alliance (MCOA), a collaborative effort of local conservation organizations, is on the front line of monitoring these threats from Belfast Bay to the Harraseeket River.
Midcoast Conservancy, and our volunteer captains, sample water quality at 13 sites in the Sheepscot and Medomak estuaries from May through October. Through the scientifically rigorous collection of environmental data, we are able to evaluate the health of our estuaries, submit high-quality data to the state for regulatory decisions, and inform restoration priorities throughout the midcoast. And not only is this important work, but, yeah, we get the added bonus of spending time out on some of the most spectacular waters this side of the mid-Atlantic Ridge.
And we would be remiss if we did not mention that one of the best ways to ensure healthy waters is to protect and steward the land.
These are the environmental water quality parameters we monitor:
Clarity: Water clarity is very important in understanding how much light is able to reach the ocean floor. Phytoplankton and marine vegetation, such as eelgrass, rely on sunlight to conduct photosynthesis to produce energy and support many life cycles.
Total Nitrogen: In most estuary systems, increased nitrogen levels can lead to phytoplankton blooms which can cause low dissolved oxygen levels as well as potentially contaminate shellfish with toxins. Nitrogen can enter the estuary from runoff from fertilizers or failing septic systems.
Dissolved Oxygen: This measures how much oxygen is present in the water. This is important as all marine animals need oxygen to live and grow. Several factors can affect dissolved oxygen, such as temperature, salinity, and nutrient loads. For example, cold water can hold more oxygen than warmer waters. When large areas of the estuary have low dissolved oxygen levels, very little can survive. These areas are called "dead zones" and are important to monitor.
pH: Increasing CO2 levels in the atmosphere lead to ocean acidification. As the marine environment gets more acidic it is difficult for shellfish, like clams, oysters, and lobsters to form their shells.
Temperature: The Gulf of Maine is warming faster than almost any other ocean surface on the planet. It is important to monitor this change, as some of the species that we’ve historically seen thriving in the region are migrating to cooler waters, and warmer water species are being seen more frequently.
Salinity: Estuaries are influenced by both freshwater and saltwater. Knowing the salinity, or how much salt is in the water, can help identify the source of the water.
Thank you to our conservation partners at MCOA, our volunteer captains, and the generous support of our members for allowing this important water quality monitoring program to continue!
