Observing Winter Carbonate Chemistry Dynamics Throughout the Mid-Atlantic Bight Shelf Using Novel Glider Technology

Abstract

Increased atmospheric carbon dioxide (CO2) has led to global climate change and ocean acidification (OA) via the absorption of atmospheric CO2 by the ocean. Coastal shelves are also affected by various processes that influence the acidity of seawater, causing acidity to vary over time and space. These variations in ocean acidity can negatively impact marine species, especially calcifying organisms such as surfclams and sea scallops. In the Mid-Atlantic Bight (MAB), a subsection of the U.S. Northeast Shelf (NES), this variation in acidity generates ecological and economic concerns as the MAB is home to some of the nation’s most productive and profitable estuaries and fisheries. In this study, Rutgers University (southern MAB) and Stony Brook University (northern MAB, Hudson Canyon) deployed two gliders equipped with sensors measur-ing depth, temperature, salinity, pH, dissolved oxygen, and chlorophyll to monitor winter 2021 carbonate chemistry conditions on the shelf as well as in slope waters of the MAB. For both deployments, measured pH and calculated aragonite saturation state (Ω_arag) showed opposing patterns, with high pH and low Ω_arag in shelf/nearshore and low pH and high Ω_arag in slope waters. These trends were attributed to different driving factors whereas pH was more influenced by biological processes (i.e. photo-synthesis) and Ω_arag was influenced mostly by thermodynamics and chemical factors (i.e. temperature, total alkalinity). The results of this study underscore the importance of monitoring coastal acidity to understand potential impacts on important species.