
About The Species
U.S. farmed hard clams are a smart seafood choice because they are sustainably grown and harvested under U.S. state and federal regulations.
Appearance
- Adult hard clams are just less than 3 inches, but can reach up to 5 inches.
- The shell is thick, grey to white in color, and has outer concentric growth rings.
- The inside of the shell is white with violet markings.
- Some hatchery raised clams have dark, zigzag stripes across the shell known as “notata”.
Biology
- Are of the shellfish family. Like oysters, mussels, and scallops they are bivalve mollusks, and have a hinged shell.
- Clams have slow growth rates and can live 12-20 years on average, and up to 40 years.
- Adults are sessile – they stay in one place – and inhabit both intertidal and sub-tidal areas.
- Clams burrow into the sediment, leaving only their siphons expose to feed.
- Hard clams prefer saline water and cannot survive if the salt content is too low.
- Each female can produce between 1 and 5 million eggs during a spawning event.
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, 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.