navigation

Atlantic Surfclam

Spisula solidissima

Atlantic surfclam

Also Known As

  • Surfclam
  • Hen clam
  • Bar clam
  • Sea clam

U.S. wild-caught Atlantic surfclam is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.

Population

Above target population level.

Fishing Rate

At recommended level.

Habitat Impacts

Fishing gear used to harvest surfclams has negative impacts to habitat, but the fishery is managed to minimize these impacts, particularly to sensitive habitat.

Bycatch

Fishing gear used to harvest surfclams is designed to minimize bycatch.

  • Availability

    Year-round. Sold processed, rather than live, in fresh, frozen, and canned products such as breaded clam strips, minced clams, stuffed clams, chowders, and broth.

  • Source

    U.S. wild-caught from New England to North Carolina. The United States is the only source of Atlantic surfclams.

  • Taste

    When cooked, the white meat is mild and sweet.

  • Texture

    Chewy.

  • Color

    The raw meat is whitish-orange. Cooked meat ranges from ivory to golden yellow, with some dark areas.

  • Health Benefits

    Surfclams provide low-fat, high-quality protein and are an excellent source of selenium and niacin.

The U.S. Fishery

Fishery Management

  • NOAA Fisheries, the Mid-Atlantic Fishery Management Council, and state resource management agencies manage the surfclam fishery.
  • Managed under the Surfclam-Ocean Quahog Fishery Management Plan:
    • Fishermen must have a permit to harvest surfclams.
    • Individual transferable quota (catch shares) program – managers set an annual catch limit for federal waters and allocate it among individual fishermen or vessel owners. These quotas can be sold or leased.
    • Minimum size, which can be suspended by managers if they can demonstrate the harvest of small surfclams is below a certain threshold.
    • Closed areas due to environmental degradation or to toxins that cause paralytic shellfish poisoning (PSP).
    • Fishermen harvesting surfclams from Georges Bank have additional requirements under the PSP testing protocol.
    • Mandatory vessel monitoring systems.
    • Fishermen must maintain and submit logbooks of each fishing trip to document catch.
  • Surfclams support valuable fisheries in New Jersey and New York state waters (within 3 miles of shore); state authorities are responsible for managing these fisheries.

Harvest

  • In 2019, commercial landings of surfclam totaled more than 34.3 million pounds and were valued at $29.3 million, according to the NOAA Fisheries commercial fishing landings database
  • Surfclams are the most important commercial clam species harvested in the United States.
  • Commercial fishermen harvest surfclams with hydraulic clam dredges—essentially large, heavy sleds pulled along the sea floor. High-pressure jets blast water into the sediment, which temporarily liquefies it and allows a steel blade to pass through the first few inches of substrate and scoop the clams onto the dredge, where they are captured in a cage made of steel bars.
  • Atlantic surfclams burrow into sandy bottoms on the continental shelf, an environment that is thought to recover quickly after a hydraulic clam dredge passes over it.
  • The bars on commercial clam dredges are spaced several inches apart so they do not collect anything but the targeted surfclams.
  • The surfclam fishery is managed under an individual transferable quota program that provides fishermen with more flexibility on when to fish, slows the pace of the fishery, and increases its efficiency, significantly reducing bycatch.

The Science

Population Status

  • According to the 2020 stock assessment the surfclam stock is not overfished and is not subject to overfishing. Summary stock assessment information can be found on Stock SMART.

Location

  • Atlantic surfclams are found in the western North Atlantic from the southern Gulf of St. Lawrence to Cape Hatteras, North Carolina.
  • They’re most abundant on Georges Bank, the south shore of Long Island, New Jersey, and the Delmarva Peninsula.

Habitat

  • Juveniles burrow in medium- to fine-grain sand in waters 30 to 80 feet deep.
  • Adults prefer medium- to coarse-grain sand and gravel from beach zones to over 160 feet deep.
  • Surfclams prefer more turbulent waters and bury themselves just below the sediment surface.

Physical Description

  • Surfclams are the largest bivalves found in the western North Atlantic.
  • They grow up to 8.9 inches, although clams larger than 7.9 inches are rare.
  • Their shells are thick, triangular, and yellowish-white with rounded edges and concentric ridges.
  • Shells do not close fully and gape slightly.

Biology

  • Surflclams can live up to 35 years.
  • On average, surfclams living in open water live longer than those living inshore.
  • Surfclams grow fast, reaching a harvestable size of about 5 inches in 5 to 7 years.
  • Growth rates depend on water temperature—southern surfclam populations in warmer water grow more slowly than the more northern populations.
  • Some are able to reproduce by age 1, but most spawn by the end of their second year.
  • Surfclams spawn from late spring through early fall.
  • They shed their eggs and sperm directly into the water column.
  • Larvae spend about 3 weeks in the water column as plankton before settling to the bottom to live.
  • Surfclams are planktivorous filter feeders, straining tiny plants out of the water to eat.
  • Larval surfclams eat algal cells.
  • Adults primarily feed on diatoms, green algae, and naked flagellates.
  • Snails, crabs, shrimp, and fish, including haddock and cod, feed on surfclams.

Research

  • Scientists from NOAA’s Northeast Fisheries Science Center, along with industry and academic partners, survey clam populations every 3 years and usually follow these surveys with a full stock assessment.
  • A few species of algae cause Harmful Algal Blooms (HABs), which can have negative impacts on fish, marine animals, birds, and humans. Species of Alexandrium cause HABs in New England that are commonly referred to as “red tides.” Alexandrium toxin becomes concentrated in shellfish such as surfclams. The shellfish themselves are not affected by the toxin, but eating shellfish tainted with this toxin can lead to paralytic shellfish poisoning (PSP), a potentially fatal human illness. There are large-scale monitoring programs all along the coast to assess toxin levels in shellfish; if toxins are detected these areas are immediately closed to harvesting. Contamination from PSP has had a huge impact on fisheries for surfclams. Georges Bank, where almost a third of the surfclam stock is found, has been closed to fishing since 1990 due to the presence of PSP toxins in surfclam meats. In January 2013, a portion of Georges Bank was reopened to the harvest of surfclams and ocean quahogs by vessels using a new PSP testing protocol that was developed through the collaborative efforts of industry, scientists, and managers. This will allow safe harvest of these abundant Georges Bank resources.

Last updated: 12/28/2020