After more than a century of decline, the harvest of oysters from the Chesapeake Bay has quadrupled over the last four years. This increase has inspired a debate over whether more -- or fewer -- restrictions are needed on the harvest of the Bay's keystone species.
Watermen dredged and scooped about 433,000 bushels of oysters from the Bay during the most recent season, from October 2013 to March 2014, according to the Maryland Department of Natural Resources. That compared to 101,000 bushels in the 2009 - 2010 season, and 26,000 bushels in 2004-2005.
Scientific sampling suggests that oyster populations – not just oyster harvests -- have been rising over the last four years.
One reason for the rebound could be the fact that, four years ago, Maryland created sanctuaries to prohibit the removal of the shellfish from 24 percent of the Bay’s remaining oyster reefs.
Biologists say another explanation for the increase is that parasitic diseases called MSX and Dermo that ravaged the Bay’s oysters in the 1980s and 1990s are no longer killing as many, perhaps because the oysters are evolving resistance to the diseases. Good weather conditions could also be a cause of the oysters' increased tolerance for disease -- and, of course, weather conditions can change.
Because oysters are still at risk -- and still at a tiny percentage of historic population levels -- some scientists argue that more sanctuaries and catch restrictions -- or even a temporary moratorium on harvesting -- might be necessary to really bring back the ecologically important species.
Watermen, on the other hand, argue that no more restrictions are needed, and that sanctuaries and bans on harvesting oysters are economically devastating to some waterfront communities.