D M R   N O T I C E

Water Monitoring Sensors

AUGUSTA, ME—The Maine Department of Marine Resources (DMR) has installed three new sensors in Boothbay Harbor, including one paid for with an $11,000 grant from the Maine Outdoor Heritage Fund (MOHF), that will help researchers understand how ocean acidification and dissolved oxygen levels can impact Maine’s marine life and ecosystem health.

The sensor purchased with the MOHF grant will monitor pH levels, which is a measure of waters acidity. The other two will measure carbon dioxide concentration, which can impact acidity, and dissolved oxygen, a key indicator of water quality. The three new sensors will soon begin providing data that will be publicly available through a DMR web portal.

Research shows that approximately 30 percent of the excess carbon dioxide that goes into the atmosphere from man-made sources like automobile emissions has dissolved into the oceans, increasing the acidity of the ocean by a similar amount. Low levels of dissolve oxygen can cause widespread shellfish mortality and often coincide with acidification.

Data from the sensors will be integrated into an existing system managed by DMR that records sea surface temperatures in what is the longest running series of ocean temperature observations on the Atlantic Coast. Dating back to 1905, the temperature series today includes other oceanographic and meteorological variables such as air temperature, relative humidity, barometric pressure, wind speed, and tide height.

“Having the resources to continuously monitor changes in acidification, dissolved oxygen and carbon dioxide concentration will provide important information over time that we can use to evaluate trends,” said DMR Scientist Jesica Waller, who is coordinating the project.

The project addresses a goal adopted in 2015 by a Commission established by Maine’s legislature to study the effects of ocean acidification. The Commission unanimously supported the need to invest in Maine’s capacity to monitor and investigate the effects of ocean acidification on commercially important species.

Crustaceans, including lobsters, as well as other shellfish like softshell clams, all have shown sensitivity to ocean acidification and poor water quality associated with low levels of dissolve oxygen. Continuous long-term data collection is essential to understanding the environmental threats to our valuable marine species and ecosystem, said Waller.

The datasets from the sensors will also be incorporated into undergraduate programming at the UMaine Darling Marine Center and the Bigelow Laboratory for Ocean Sciences. Because the effects of ocean acidification and poor water quality are not immediately apparent, education is important to illuminate the seriousness of the issue, said Waller.

“Continuous pH, CO2 and O2 data provides critical information for understanding and modeling changes in our coastal waters,” said David Fields, a senior research scientist at Bigelow Laboratory for Ocean Sciences. “These new sensors will add significantly to the DMR’s capacity to manage our local resources and will provide an essential resource to the growing coalition of public and private collaborators that work with DMR.”

“By many measures, Maine is the most susceptible state on the east coast to acidification due our dependence on organisms that grow shells and low buffering capacity of coastal water, said Damian Brady, Associate Professor with the Darling Center. “The Department of Marine Resources has long been a leader in observing changes in coastal ecosystems, so adding acidification monitoring to their portfolio is an important step toward understanding whether our marine resources are under threat.”