Atlantic Surf Clam

• Its shells record annual growth rings that make it possible to date individuals of more than thirty years and to reconstruct ocean temperatures in past decades.
• It lives up to thirty years, a notable lifespan for a shelf-dwelling clam.
• It supports one of the most valuable shellfish fisheries on the east coast of the United States, and is the clam that goes into clam chowder and fried clam strips.
• Its population is shifting northwards and into deeper water as the north-west Atlantic warms, one of the best-documented cases of a fishery resource relocating because of climate.
• It is sensitive to thermal stress: warm summers cause die-offs at the southern limit of its range.

Skeleton type

Invertebrate - external calcareous bivalve shell (mollusc)

Habitat and environment

Coastal sandy bottoms of the north-western Atlantic, down to about 60 m

Sexual maturity

2 years

Sources consulted: Dillwyn (1817); NOAA Fisheries; Weinberg et al; ScienceDirect (Hughes 1989); Science Advances, How colonial animals evolve; Wikipedia, Zooid

The pins mark the parks and dive sites where its presence is documented.