Geoduck
Geoduck
Panopea generosa
Also Known As
King Clam, Elephant Clam, Gweduck, Goeduck, Goiduck
Quick Facts
Weight
Up to 7 pounds
Length
Shell typically 6 - 8 inches; siphon can be up to 3 feet
Region
Alaska,
West Coast
About the Species
Geoduck (pronounced “gooey-duck”) can be found along the West Coast of the United States from Alaska to Baja California. There is both wild harvest and a growing geoduck aquaculture industry, particularly in Washington State. The majority of Washington’s geoduck farming takes place in southern Puget Sound.
Environmental Impact
Geoducks provide net environmental benefits by removing excess nutrients and improving water quality.
Feeds
Growing geoducks requires no feed – they filter phytoplankton directly from the water column.
Farming Methods
Geoducks are planted in PVC pipes on intertidal beaches until they are large enough to burrow into the sediment.
Human Health
Shellfish toxins and bacteria occur naturally in the environment and can cause foodborne illnesses. State and federal regulations require monitoring of farmed geoducks to ensure they are safe to eat.
Appearance
- Geoducks are characterized by a small shell and very long siphon, or "neck."
- The long “neck” has two openings at the end – one for taking in oxygen and phytoplankton and one for releasing excess water.
Biology
- Geoducks are long-lived; the oldest ever recorded was 168 years old.
- Geoducks burrow into the sediment about 1 foot per year to a depth of 3 feet.
- In the first 3-5 years, geoducks grow to 1.5 pounds, though they make not reach maximum size, about 7 pounds, for 15 years.
- Females release between 1 and 2 million eggs per spawn.
Fishery Management
- Permitting for shellfish aquaculture is governed by federal, state and local governments.
- The federal agencies involved are NOAA, the Army Corps of Engineers, Fish & Wildlife Service, US 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. //
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Grilled tuna lemon with mayo. Credit: North Carolina Sea Grant/Vanda Lewis.
