Blue Carbon emphasizes the role of aquatic plants in the carbon cycle. However, the global importance of submerged aquatic vegetation (SAV) is highly uncertain, as <10% of this resource has been mapped. Satellite technology now provides daily coverage of the global coastal environment at 3 m resolution, enabling the mapping of Blue Carbon system dynamics at spatial and temporal scales not previously attainable. We employed satellite imagery from the Planet/Dove constellation to quantify the monthly dynamics of SAV Blue Carbon potential at five locations in the Chesapeake Bay ranging from the upper Bay dominated by freshwater SAV to the oceanic coastal lagoons exclusively vegetated by eelgrass (Zostera marina L.). We employed machine learning to classify the images and a physics-based model of reflectance to quantify Blue Carbon abundance. Since 2018, the SAV meadows occupying the oceanic coastal lagoons were temporally stable, supporting a mean above-ground biomass of 40 g C m^-2. Meadows in the polyhaline lower Bay supported less biomass (~34 g C m^-2) with a seasonal amplitude characterized by winter declines and summer re-growth. SAV meadows covered extensive mudflats in the freshwater uppermost portion of the Bay at extremely high density (>40 g C m^-2) in summer but disappear almost completely during winter. Our efforts to quantify the seasonal dynamics of SAV from satellite imagery will improve the assessment of Blue Carbon in the Chesapeake Bay and provide an automated workflow environment that can be scaled to routine assessment of SAV dynamics across the globe.

Primary Presenter: Richard Zimmerman, Old Dominion University (rzimmerm@odu.edu)

Authors:

Victoria Hill, Old Dominion University  (vhill@odu.edu)

Kylie Harrison, OLd Dominion University  (kharr102@odu.edu)