Pacific Oyster

A cluster of Pacific oysters in eelgrass.

About The Species

U.S. farmed Pacific oysters are a smart seafood choice because they are sustainably grown and harvested under U.S. state and federal regulations.


  • Can reach up to 10 inches in length.
  • The shell is elongated, thick, rough and sometimes sharp. The inside of the shell is white to off/white with purple streaks.
  • The shell has a “cupped” shape to it, giving rise to its alternate name “Pacific cupped oyster.”
Behavior and Diet
  • 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 sub-tidal areas.
  • Have fast growth rates and high reproduction rates.
  • First mature as males, then later develop female reproductive capabilities.
  • Each female can produce between 50 and 200 million eggs during a spawning event.
  • Permitting for shellfish aquaculture is governed by federal, state and local governments.
  • The federal agencies involved are NOAA, the Army Corps of Engineers, U.S. Fish & Wildlife Service, U.S. Department of Agriculture, the Environmental Protection Agency, the Food and Drug Administration, the Bureau of Ocean Energy Management, and the Coast Guard.
  • Shellfish farms must adhere to federal regulations including those in the Magnuson-Stevens Fishery Conservation & Management Act, the Endangered Species Act, the National Environmental Policy Act and the Clean Water Act.
  • Information on shellfish aquaculture permitting can be found in the Shellfish Growers Guide.
  • A variety of shellfish aquaculture tools, including maps and models, are available to coastal managers.