Atlantic surfclam

Atlantic surfclam. The Atlantic surfclam (*Spisula solidissima*) is a large, commercially significant bivalve mollusk native to the continental shelf of eastern North America. It is a key species in benthic ecosystems and supports one of the most valuable shellfish fisheries in the United States. The species is known for its robust, triangular shell and its adaptation to high-energy, sandy environments.

Description

The Atlantic surfclam possesses a thick, equivalve shell that can exceed 20 centimeters in length, making it one of the largest clam species in its range. The exterior is sculpted with concentric ridges and is typically a dull gray or tan color, often stained by sediments. Internally, the shell is white with a distinctive, large, muscular foot and prominent siphons. The species is often compared to the smaller and more southern Atlantic quahog (*Mercenaria mercenaria*). Key anatomical features are studied at institutions like the Virginia Institute of Marine Science and the National Oceanic and Atmospheric Administration.

Distribution and habitat

This species is found along the continental shelf from the Gulf of Saint Lawrence southward to Cape Hatteras in North Carolina. Its core population and fishery are centered on the Mid-Atlantic Bight, particularly off the coasts of New Jersey and Long Island. The Atlantic surfclam is a burrowing infaunal species, exclusively inhabiting clean, well-sorted sandy or sandy-gravel substrates from the intertidal zone to depths of over 60 meters. It is highly adapted to the dynamic, wave-swept environments of the open coast, unlike related species in calmer bays like the Chesapeake Bay.

Life history and ecology

Atlantic surfclams are broadcast spawners, releasing gametes into the water column primarily during summer months. Planktonic larvae drift for several weeks before settling and metamorphosing into benthic juveniles. They are relatively fast-growing, reaching market size in about 5-7 years, and can live for over 30 years. As filter feeders, they consume phytoplankton and particulate organic matter, playing a role in nutrient cycling. Major predators include Atlantic sea scallop dredges, various demersal fish like cod, and sand tiger shark species. Population dynamics are influenced by climate patterns and have been impacted by events like the 1995 Atlantic hurricane season.

Fishery and uses

The Atlantic surfclam supports a major industrialized fishery managed under the Magnuson–Stevens Fishery Conservation and Management Act by the New England Fishery Management Council. The fleet, based in ports like Point Pleasant, New Jersey and New Bedford, Massachusetts, utilizes large hydraulic dredges. Annual landings are valued in the tens of millions of dollars. The meat is primarily processed into chopped clams for products like clam chowder and breaded strips, with much of the harvest handled by companies like Clearwater Seafoods. The shells are also used as a calcium supplement in agriculture and poultry feed.

Conservation status

The Atlantic surfclam fishery is considered a sustainable success story due to strict science-based quotas and effective management by NOAA Fisheries. The stock is not listed as threatened or endangered by the International Union for Conservation of Nature or under the Endangered Species Act. However, populations face long-term threats from ocean acidification and warming sea temperatures associated with climate change, which affect growth and reproduction. Research and monitoring are conducted by the Northeast Fisheries Science Center and academic partners like the University of Rhode Island.

Category:Bivalves of the Atlantic Ocean Category:Commercial molluscs