Here is an interesting oyster article:

A mystery in the oysters: Scientists probe unexplained die-off Chesapeake’s farm-raised oysters - Eastern Shore Post

Few people realize the terrible decimation of the oyster population in Chincoteague Bay. O

From a 2013 Maryland study:

Oyster Results: Status and Trends
1. Recent Status
None of the 28 documented shell bars in the Coastal Bays have living oysters.
In addition to the 150 handscrape tows taken in 1994 on the former oyster bars of Chincoteague Bay, almost 4,000 clam dredge stations throughout the coastal system have been sampled over the past twenty years and never has a live oyster been found on the old oyster grounds. To a large extent the bars themselves have been buried by sediment, greatly reducing this ecologically important habitat.