Eastern Oyster
The Eastern oyster is treasured as food by humans and other species. They are habitat for fish, crabs, and other critters—and because as filter feeders, they help filter the water. Centuries ago, they were plentiful. In some places, reefs were so big that ships had to navigate around them. Since then, in many areas, the populations have dwindled to just a few percent of what they once were. This is due to disease, overharvesting, habitat loss, and poor water quality.
Appearance
- Reaches 8 inches at maturity.
- The shell has smooth edges and is oval in shape. The inside of the shell is white to off-white to brownish in color.
- The shell has a “cupped” shape to it, giving rise to its alternate name “American cupped oyster.”
Biology
- Are of the shellfish family. Like mussels, clams and scallops they are bivalve mollusks, and have a hinged shell.
- Adults are sessile—they stay in one place—and inhabit both intertidal and subtidal areas.
- Have fast growth rates and high reproduction rates.
- First mature as males, then later develop female reproductive capabilities.
- Each female can produce over 100 million eggs during a spawning event.
Where They Live
Range
- Eastern oysters are found along eastern North America from the Gulf of St. Lawrence to the Gulf of Mexico. They are found in the middle and lower Chesapeake Bay and its rivers. They are the only species of oyster native to this region.
Habitat
- Eastern oysters live in brackish and salty waters from 8 to 35 feet deep. In some warmer areas, they are able to live in the intertidal zone. They attach to firm bottom areas, and to each other, to grow into reefs. These reefs provide habitat for fish, crabs, invertebrates, macrofauna, and birds.
Source: NOAA Fisheries