Wildlife Fact Sheet

Oyster

Ostreidae

Lifespan | Up to 20 years
Habitat | As babies (called spat), oysters settle on top of other oysters on the seafloor to form oyster reefs. Oysters can also be grown by humans in oyster farms.
Range | In the Atlantic, oysters range from Canada to Argentina, and in the Pacific, from Japan to Washington state and even as far south as Australia.
Preferred Food | Oysters are filter feeders and pass water over their gills to get oxygen to breathe and plankton to eat.

About

Oysters are among the hardest working animals in the ocean. As adults, oysters can filter 25-50 gallons of water each day. Back in the day, the entire Chesapeake Bay could be filtered in just five days before oyster populations dropped to just 1% of their historic levels. In fact, oysters are part of the reason the Chesapeake got its name—it’s an Algonquin Native American word that means “Great Shellfish Bay.”

Because oysters filter massive amounts of water, they are vulnerable to what ends up in the ocean. Their numbers can drop if there are increased amounts of runoff or coastal erosion (which is when you would want MORE animals filtering the water). Oysters also can collect toxins in their bodies which can be harmful for the humans who eat them.

Oysters do much more than filter water, though. Oysters latch onto each other to form big reefs that provide shelter for fish and crabs and that stabilize muddy estuary bottoms. Also, filtered water provides better conditions for seagrass, a crucial habitat and breeding ground for animals like rockfish and blue crabs to grow.

Did You Know?

Oysters take on the flavor of the water where they grow up. East Coast oysters tend to be saltier and brinier while West Coast oysters tend to be a little sweeter.

Get Ocean Updates in Your Inbox

Sign up with your email and never miss an update.

This field is hidden when viewing the form
Name(Required)
By providing your email address, you consent to receive emails from Ocean Conservancy.
Terms & Conditions and Privacy Policy


This field is hidden when viewing the form
Email Opt-in: Selected(Required)

Fast Facts

  • Oyster
  • Oyster