INVESTIGATING POTENTIAL IMPACTS OF CLIMATE CHANGE ON THE GULF OF MAINE THROUGH WATER QUALITY MONITORING AND MYTILUS EDULIS AS BIO-INDICATORS

The Gulf of Maine is one of the fastest-warming bodies of water on Earth. In Blue Hill Bay, the second largest bay in Maine, the Shaw Institute has documented an increase of SST by more than 2^oC over the past two decades, causing noticeable effects on the health and biodiversity of the bay. Drastic population declines have been observed in native species while warm-water invasive species have boomed in their place. Blue mussels, a keystone species in Gulf of Maine coastal ecosystems have decreased by more than 60% over the last 40 years, and their loss could cause cascading extinctions throughout the food web. This study investigated the relationship between ocean warming, coastal acidification, and decreasing Mytilus edulis populations in Blue Hill Bay. Two field sites, a thriving mussel bed and a declining mussel bed, were selected and mussel larvae collection boxes were placed in random configuration within the intertidal zone from June to October. Boxes were retrieved in October and their contents analyzed for mussel spat, physical size, population size, pH-induced shell deterioration, and predation. Water quality parameters such as temperature, pH, DO, turbidity, flow velocity, and chlorophyll a were collected twice weekly at each site during mussel box deployment. Classification of sediment type and size, as well as temperature and pH of the sediment were also investigated as potential factors influencing the decline of blue mussels. Understanding the scope of climate change impacts in the Gulf of Maine as well as developing mitigation and response strategies is essential in being prepared with globally beneficial solutions to a warming and acidifying ocean. Ecological implications of changing water quality and sediment parameters on blue mussel population declines across the Gulf of Maine will be discussed.