Characterization (δ13C, δ15N and TOC/TN) of marine sediments from restored seagrass (Zostera marina) meadows in coastal lagoons of Virginia.

Noah Egge, University of Virginia, noah@virginia.edu (Presenter)
Stephen Macko, University of Virginia, sam8f@virginia.edu

Restoration of the Chesapeake Bay and its neighboring coastal areas has been a major focus of scientific research in the last ten years. The decline of the area is often linked with the explosive population growth and subsequent increases in agriculture and urbanization of the region. In the coastal bays of Virginia, large efforts have been made to restore seagrass (Zostera marina) meadows, which were devastated by a combination of events in the 1930s. As a result of the restoration efforts begun in 2001, seagrass has come to dominate portions of South Bay and Hog Island Bay.

Sedimentary characterization (δ¹³C, δ¹⁵N, total organic carbon and total nitrogen) is used to assess sources of organic matter in marine environments. Push cores were used to collect samples from sites that have different records of seagrass cover. Sediments dominated by seagrass contain organic matter enriched in ¹³C relative to autochthonous algal sources. Within the sediment record there are two regions that show heightened ¹³C content—one near the surface and another at lower depths. Organic matter enriched in ¹³C near the surface is from current seagrass cover. Similar characteristics of sediment deeper in the core imply that the area was previously dominated comparable vegetation. Results may be used as a proxy to infer the spatial extent of the historic (prior to 1930) presence of seagrass and guide future restoration projects.

Presentation Type:  Poster

Session:  Global Change Impact & Vulnerability   (Tue 11:30 AM)

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Poster Location ID: 174