If you are interested in volunteering with the Great Bay Oyster Restoration program or other environmental stewardship programs, reach out to the New England Stewardship Network. These seed oysters are held in floating crates, through which water is pumped. We helped by volunteering a few hours on a sunny morning to count oyster spats that will be delivered to local homeowners that will monitor their growth. Better grow-out times are achieved using Chilean spat, bought at 7 - 12 mm size. Now about 8 years underway there is a community effort to restore the oyster population. During the 1980s a deadly disease was introduced to the region that destroyed most of the oyster beds. The oysters were key to the health of the estuary. Great Bay had a long tradition of large populations of oysters that helped filter and clean the waters. Curious what an oyster spat is? Well, it's a baby oyster and UNH has teamed up the The Nature Conservancy and volunteer Oyster Conservationist to help repopulate this body of water with oysters. Chesapeake Bay: Nature of the Estuary, A Field Guide by Christopher P.Although a majority of our projects are completed in the Lakes Region, this past July we were able to spend a morning at the UNH Jackson Estuarine Laboratory on the shores of the Great Bay in Durham to help count oyster spats.Life in the Chesapeake Bay by Alice Jane Lippson and Robert L.An adult oyster can filter up to 50 gallons of water in one day under certain conditions.Historically, oysters were only eaten during months whose names contain an “R.” This is because oyster quality is poor right after they have spawned, and because oysters would spoil without refrigeration during warmer months.Oysters are one of the most important commercially harvested species in the Chesapeake Bay.During cooler months, oysters can live out of the water for extended periods of time. However, freezing air temperatures will kill them. This allows oysters to survive for a long time without having to open their shells to feed. The cavity within an oyster’s shell is always filled with water.Most oysters less than one year old are male, while most older oysters are female. Settled juvenile oysters are called "spat." Many oysters change sex over the course of their lifetime. Once larvae find a suitable surface to settle on, they secrete a cement-like substance, which fixes the left shell (also called a valve) into place. Oysters can attach to one another, forming dense reefs (also called oyster bars, beds or rocks) that provide habitat for many fish and invertebrates.
They eventually mature to the pediveliger stage, when they can ‘set’ or attach to hard substrate. Over the next two to three weeks, oyster larvae are planktonic (when an organism is too small to propell itself through water). Adults grow larger and stronger as the weather cools. In less than 24 hours, fertilized eggs develop into free-swimming larvae. Females can produce about 100 million eggs each year. After spawning, oysters are thin because they have used up their stored food reserves. Spawning occurs in early summer when water temperatures and salinity levels rise. Adults release eggs and sperm into the water. Shorebirds feed on adult oysters exposed on intertidal flats. Oysters are prone to infection by parasites that cause the aquatic diseases MSX and Dermo. They have other natural predators that include:Īnemones, sea nettles, and other filter feeders feed on oyster larvae.įlatworms and mud crabs feed on new spat.īlue crabs and some fish feed on older spat and first-year oysters. Feedingįilter feeders, oysters feed on plankton by opening their shells and pumping water through their gills. The right or top shell is flat, while the left or bottom shell is cupped, with a purple muscle scar on the inside.
Two rough shells enclose its soft body and vary in color from white to gray to tan. AppearanceĮastern oysters usually grow to three to five inches in length, but can reach a length of eight inches.
It forms reefs in brackish and salty waters throughout the Chesapeake Bay. Also known as the American or Virginia oyster, the eastern oyster is a bivalve with two rough, whitish shells.
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