Resilience of Seagrass and Associated Carbon Stocks to Storms (2024)

Undergraduate: Olivia Key

Faculty Advisor: Antonio Rodriguez
Department: Earth, Marine, and Environmental Sciences

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Seagrass beds support healthy estuaries and are among the most efficient carbon sinks. High-salinity seagrass commonly forms behind barrier islands in areas frequently impacted by storms. Storms can remove some of the seagrass bed as new inlets form and erode areas, or enhance preservation of the seagrass bed as sand is deposited. Researchers commonly assess seagrass carbon stocks from surface samples and assume loss of seagrass area equates to loss of the carbon stock. However, the relationship between carbon burial in seagrass beds and the shifting depositional environment of NC seagrass meadows has yet to be investigated. The main goal of this research is to develop a depositional model for high-salinity temperate seagrass meadows that captures changes in carbon storage associated with storms and spatial variability in sediment composition across the meadow._x000D_
North Carolina has the largest seagrass area on the east coast of North America and ~80% of that area is behind the Outer Banks. We collected two transects in Core Sound extending across the seagrass meadow. The older beds and the surface beds had similar carbon stocks. Cross sections from both sites suggest that rapid deposition of sand buried former seagrass beds, preserved a portion of their carbon stock, and seagrass recolonized that sandy substrate. This work underscores the great resilience of seagrass beds to storm burial events in the past and the need to define carbon stock as the entire seagrass depositional system as opposed to surface beds.