Oysters are an integral part of the Chesapeake Bay ecosystem.  These filter-feeders naturally clean the bay by pumping water through their gills and trapping small particles of food and sediment.  One oyster can filter over 50 gallons of water in one day.  Because of over-harvesting in the past, disease, and habitat loss, populations in the Chesapeake Bay are less than 1% of their historical size (NOAA).  To put this into perspective, in the late 1800s there were enough oysters in the Bay that they could filter the entire Bay in three or four days; today there are so few oysters that it takes almost a year to filter the entire Bay.

In addition to filter-feeding, oysters provide habitat and food for other organisms.  Oyster larvae grow on top of adult oysters, forming layers that build upward and outward as more oysters are added.  Small fish and invertebrates like crabs often hide in between oyster shells.

The 2004 Chesapeake Bay Oyster Management Plan oversees oyster harvesting, establishes sanctuaries, treats the effects of disease, and restores reefs with hatchery-raised oysters.  One way to restore reefs is with Oyster Blox.  These Blox provide new habitat for oysters and restocking the reefs.  The Blox will be installed in the Elizabeth River as an “oyster castle” in hopes that it will contribute to the continuing improvement of the river.

Watch this time lapse video of oysters filtering a dirty tank!  This clip is an excerpt from the Chesapeake Bay Foundation’s documentary Common Ground:  Saving the Chesapeake’s Oysters.