Shellfish in Maine

There are many different varieties of shellfish in Maine in its coastal waters. This short guide will introduce you to some of the more notable species of shellfish throughout the coast. For more information about various species, please see the Maine Sea Grant Seafood Guide. For more harvesting information, please see the Maine Department of Marine Resources Shellfish Identification Guide.

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Soft-Shell ClamsMusselsHard ClamAtlantic Surf ClamAmerican or Eastern OysterEuropean OysterAtlantic Razor ClamMahogany QuahogCommon PeriwinkleCommon Moon SnailWaved WhelkStimpson’s Whelk

Soft-Shell Clams (Essok; Mya Arenaria)

Soft shell clams support one of the largest fisheries in Maine, the soft-shell clam fishery and have been harvested here for over 10,000 years. This clam is usually gray in color, and lives in sandy or muddy intertidal areas.3,4 It takes about three to four years for a clam to grow to legal size to harvest. The harvest size is minimum 2 inches. Currently there is now maximum harvest size limit, however some towns are adopting a 4 inch maximum rule, so please check local regulations. In the Gulf of Maine, soft-shell clams spawn once a year.3,15 Soft shelled clams are regulated by the state Department of Marine Resources (DMR) and most coastal towns through a co-management system, that is described here. These clams are commonly steamed, fried, or served in clam chowder, and are a delicious addition to any clam bake!
Other names: steamers, longnecks

Soft Shell Clams: Bangor Daily News (Patrick Whittle)

Mussels (Massolsok; Mytilus edulis)

The blue mussel is a very common site across Maine’s coast. It is dark blue and elongated, and can be found attached to rocky or hard surfaces up to depths of 200 ft. 6,12 This mussel is commonly used in aquaculture and has been shown to be very successful in Maine’s temperate waters. 8 Blue mussels are also used in multiple climate change studies to understand how shellfish respond to various climate change scenarios and long term monitoring programs. 6,12,13  Mussels can be harvested all year and are also regulated by the DMR.
Other names: common mussel

Mussels: Photo Credit – University of Maine

Hard Clam (Mercenaria mercenaria)

Hard clams are found in the similar habitats to soft shell clams, muddy or sandy tidal areas. It grows to the legal harvest size of 2 inches within 4 to 5 years.11 These have a harder shell than soft-shell clams, and are often used in different studies to re-seed unproductive clam flat areas, as described in this report and other studies as they are thought to be more resistant to predation from green crabs.2,11 Hard clams are regulated similar to soft-shell clams under a co-management system. 
Other names: round clam, cherrystones, littlenecks, countnecks

Hard Clams: Department of Marine Resources Shellfish Guide

Atlantic Surf Clam (Spisula solidissima)

Surf clams are very large and pale, and can easily grow to 7 or 8 inches. This makes them some of the largest clams we eat and the largest type of clam living in the Atlantic. 1,14 They live in sandy areas, and are commonly found lower in the intertidal. Commonly these clams are processed and sold as clam juice, clam strips, minced clams, or bait for other fisheries.1 These clams are often collected on the beach for it’s large shell, as Dave Taft writes, “The Atlantic surf clam’s salad-plate-size shells elevate this bivalve to celebrity status among beach-going children of all ages.” 
Other names: bar clam, hen clam, skimmer, sea clam

Atlantic Surf Clams: Photo Credit – National Fisherman and Caroline Losneck

American or Eastern Oyster (Pahsapsqiyik; Crassostrea virginica)

The American or Eastern oyster gray, rough, and irregularly shaped shells.  They form reefs, and were often thought of as navigational hazards in much of colonial America.15 Traditionally, because of the large size of the reefs, these oysters were able to filter out pollutants in bodies of water like Chesapeake Bay.15  Now, they are found commonly in aquaculture leases. In the Damariscotta River, Sheepscot River, and New Meadows Ponds; there is a Vibrio Control Plan in place that restricts recreational harvest from May 1st to October 31st each year. For more information please visit the DMR website.
Other names: Wellfleet oyster, Virginia oyster, common oyster

Wellfleet Oyster: Photo Credit – JP Shellfish

European Oysters (Ostrea edulis)

European flat oysters or “Belons” are originally from Europe and were transplanted in Boothbay in the 1950s. These oysters are large and flat, and can have greenish, brown, or reddish brown shells. They enjoy hard bottom sediments, and are often retrieved by divers.5  In the Damariscotta River, there is a Vibrio Control Plan in place that restricts recreational harvest from May 1st to October 1st each year. For more information please visit the DMR website. There is also a seasonal closure statewide from June 15th to September 15th every year.
Other names: flat oyster, Belons, mud oyster, edible oyster

Flat oysters: Photo Credit – Myrabella/ Wikipedia Commons

Atlantic Razor Clams (Ensis directus)

Razor or jackknife clams have thin elongated shells and are often yellow, brown or orange. They are found in shallow subtidal areas meaning they can only be harvested at extremely low tides.7,10 The minimum size for harvest is 4 inches, however it is not often commercially fished as they are very difficult to catch.7 Click here to watch a free diver in Ireland catch razor clams underwater.
Other names: American jackknife clam

Razor Clam: Photo Credit- Gulf of Maine Sea Life & Aquarium

Mahogany Quahog (qahaksok; Artica islandica)

Mahogany quahogs have a distinct mahogany color and are small, similar in size to littleneck or cherrystone quahogs. They are considered ocean quahogs. These clams are harvested by dredging, because they live in very deep waters. They are generally known for having a tougher texture while eating, but can be prepared similar to other clams. In 2011, the folks from ClamsAhoy, John and Ted described preparing them in different ways, click here to learn more.
Other names: ocean quahog

Mahogany Quahog – Maine Clammers Association

Common Periwinkle (Pukocalahsok; Littorina littorea)

The common periwinkle is the most common intertidal snail in Maine, introduced in the 1800s from Western Europe. It has a dark or banded shell, and can often be seen in large numbers. It can grow to be 1 ½ inches. In Europe, these snails are seen as a delicacy, and are often lightly boiled in seawater before serving17.

Common Periwinkle: Science Source – Andrew J. Martinez

Common Moon Snail (Euspira heros)

Moon snails a snake gray to tan in color that can grow to 4 inches in shell length. They feed on blue mussels and soft-shelled clams, and are known to create a small hole in shells.10 They are commonly harvested to be used as bait for longline gear. 

Other names: northern moon shell

Common Moon Snail: Photo Credit Josh Fecteau

Waved Whelk (Buccinum undatum)

Waved whelks are gray, yellow or tan, and have a heavy spiral shaped shell.  Adult waved whelks are two to four inches in length and are found subtidally. Commonly, they are prepared pickled or eaten in pasta or salad dishes like Scungili.9

Other names: northern whelk, edible whelk, European whelk

Waved Whelk: Photo Credit – Gulf of Maine Inc.

Stimpson’s Whelk (Colus stimpson)

Stimpson’s whelks have a spindle-shaped shell that is dark in color and can grow up to 3 inches in length.  They are found in deeper waters, usually in sandy or muddy habitats. 

Other names: Stimpson’s colus

Stimpson’s Whelk: Photo Credit – Gulf of Maine Inc.


  1. Angoff, B. (2019) The Underappreciated Atlantic Surf Clam. Pangea Shellfish Company
  2. Beal, B.F., G. Protopoescu, K. Yeatts, J. Porada (2009) Experimental trials on the nursery culture, overwintering, and field grow-out of hatchery-reared northern quahogs (hard clams), Mercenaria mercenaria (L.), in Eastern Maine. Journal of Shellfish Research Vol. 28 Issue 4
  3. Beal, B.F., (2002) Adding value to live, commercial size soft-shell clams (Mya arenaria L.) in Maine, USA: results from repeated, small-scale, field impoundment trials. Aquaculture, 2010 P. 119-135
  4. Beaukema, J.J. (1976) Biomass and species richness of the macro-benthic animals living on the tidal flats of the Dutch Wadden Sea. Neth. J. Sea Res. 10 P. 236-261
  5. Browne Trading Company (2020) Maine Belon Oysters
  6. Chase, M.E., S.H. jones, P. Hennigar, J. Sowles, G.C.H. Harding, K. Freeman, P.G. Wells, C. Krahforst, K. Coombs, R. Crawford, J. Pederson, and D. Taylor (2001) Gulfwatch: Monitoring Spatial and Temporal Patterns of Trace Metal and Organic Contaminants in the Gulf of Maine (1991-1997) with the Blue Mussel, Mytilus edulis L. Marine Pollution Bulletin Vol. 42 Issue 6 P490-504
  7. Flanagan, Molly P., (2013)  “Investigation of Early Development and Importance of Sediment Choice in the Hatchery Production of Razor Clams, Ensis Directus” . Honors College. 111.
  8. Green, J., and R. Grizzle (2006) Aquaculture cage biofouling in the Gulf of Maine: How does the blue mussel (Mytilus edulis) out-muscle other species? Journal of Shellfish Research Vol. 25 Issue 2
  9. Gulf of Maine (2020) Waved Whelk (Buccinum undatum)
  10. Kenchington. E., R. Duggan and T. Riddell. (1998). Early life history characteristics of the razor clan1 (Ensis directus) and the moonsnails (Euspira spp.) with applications to fisheries and aquaculture. Can. Tech. Rep. Fish. Aquat. Sci. 2223: vii – 32 p. 
  11. Kraeuter, J. N., G. Flimlin, M.J. Kennish, R. Macaluso, and J. Viggiano (2009) Sustainability of northern quahogs (hard clams) Mercenaria mercenaria, linnaeus in Raritan Bay, New Jersey: assessment of size specific growth and mortality. Journal of Shellfish Research Vol. 28 Issue 2
  12. Lesser, M.P., M.A. Bailley, D.G. Merselis, J.R. Morrison (2010) Physiological response of the blue mussel Mytilus edulis to differences in food and temperature in the Gulf of Maine. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology Vol. 156 Issue 4 P 541-551
  13. Martino, P.A., D.B. Carlon, and S.E. Kingston (2019) Blue Mussel (Genus Mytilus) Transcriptome Response to Simulated Climate Change in the Gulf of Maine. Journal of Shellfish Research Vol. 38 Isssue 3. 
  14. New Jersey Sea Grant (2014) Atlantic Surf Clam and Hard Clam
  15. Oceana (2020) American Oyster, Crassostrea virginica
  16. Tan, E. B. P., & Beal, B. F. (2015). Interactions between the invasive European green crab, Carcinus maenas (L.), and juveniles of the soft-shell clam, Mya arenaria L., in eastern Maine, USA. Journal of experimental marine biology and ecology462, 62-73.
  17. URI, (1998) The Uncommon Guide to Common LIfe on Naragansett Bay, Common Periwinkle (Littorina littorea).