DV-19-07 Shell Day: Marine Monitoring Blitz

University of Maine
Parker Gassett

Ocean acidification refers to a decrease in the pH of seawater due to the absorption of CO2 from the atmosphere. An increase in atmospheric CO2 levels results in an increase of CO2 absorption and more acidic water. Shellfish, which contribute $56.0 million to the economy and 1,500 jobs for Maine residents, are particularly affected by this issue since many shellfish have shells composed of calcium carbonate. As the pH of the seawater decreases (becomes more acidic), shellfish, such as oysters, clams, and mussels have a harder time obtaining the necessary components to maintain the structural integrity of their shells from the seawater. Along the coast, this issue is amplified by the presence of rivers (freshwater has a lower tolerance for pH changes than seawater) and by nutrient runoff, which can cause blooms of phytoplankton that influence the chemistry of the water (for more information visit the NECAN website.) 

In order to engage local communities and inform the public of the issues that impact Maine’s coastal regions, a single-day water monitoring blitz will be held along the coast from Long Island Sound to Downeast Maine in August 2019. The question being asked: “What is the relationship between salinity and alkalinity?” Alkalinity is the ability of water to neutralize an acid, or in other words, resist pH fluctuations. However, testing the alkalinity of the water is not as easy as determining the salinity. Thus, the objective is to determine whether salinity could be used as a proxy for total alkalinity in order to assess the risk of coastal acidification on shellfish. Throughout the day, citizen science organizations will collect water samples and measure the temperature, salinity, and pH in each location at low, mid, and high tides. The samples will be sent to participating labs and the results will be distributed. The data gathered from this citizen-science effort will allow researchers to gain a better understanding of the local vulnerability to ocean acidification and the impacts on shellfish populations. 

Sea Grant Funds: $5,000