Population Assessment of Eastern Oysters (Crassostrea virginica) in the Seaside Coastal Bays

Declines of oyster populations and commercial harvest from the Virginia seaside coastal bays have followed similar patterns, though not as severe, as those in Chesapeake Bay. High prevalence of Dermo disease (Perkinsus marinus) and MSX disease (Haplosporidium nelsoni) coupled with over harvest and habitat destruction have dramatically reduced populations. Nevertheless, there are several promising signs that significant enhancement of the population could be achieved with well conceived restoration efforts. Oyster habitat and population distribution were examined in the coastal bay system on the seaside of the Eastern Shore of Virginia. This system is composed of barrier islands, salt marshes, broad and shallow coastal bays, intertidal mud flats, and deeper water channels. Manmade shorelines such as bulkhead and rip rap are prevalent in limited areas. This study provides the first quantitative assessment of oyster population abundance on a region wide scale in the coastal bays on the seaside of Virginia’s Eastern Shore. Our estimate of 3.2 billion oysters in this region exceeds the most recent population estimate of 1.8 billion oysters for the entire Virginia portion of Chesapeake Bay produced by the VIMS CBOPE (http://web.vims.edu/mollusc/cbope/VAPDFfiles/VABasin2006.pdf). At the time of our sampling, Dec. 2007 – June 2008, the oyster population was comprised of a wide range of sizes representing several year classes that suggest a self-sustaining population with the potential for significant expansion. The spatially-explicit oyster population GIS product developed through this work provides a valuable tool for guiding fisheries resource management and restoration activities for oysters in this region. The ultimate usefulness of this product lies in its integrative aspect as a GIS tool