Atlantic surfclam

Atlantic surfclam

Spisula solidissima

ALSO KNOWN AS:

    Surfclam, Clam, Hen Clam, Bar Clam, Sea Clam

SOURCE:

    U.S. wild-caught from New England to North Carolina
 

STATUS

  • POPULATION
  • FISHING RATE
  • HABITAT IMPACTS
  • BYCATCH
 

Click the icons to learn more about each criteria

 
 

OVERVIEW

Atlantic surfclam

Haul on deck of a clam dredge.

LAUNCH GALLERY

The largest bivalves in the western North Atlantic, surfclams support a multimillion-dollar fishery along the East Coast and are the most important commercial clam species harvested in the United States. The United States is the only source for surfclam, which is too big and too coarse to be eaten whole like other clams. Instead, they are sold processed, rather than live, in fresh, frozen, and canned products such as clam strips, minced clams, stuffed clams, chowders, and broth.

The surfclam fishery was one of the first to be managed under a fishery management plan as directed by the Magnuson-Stevens Act in 1976. It’s also the first U.S. fishery to be managed under an Individual Transferable Quota system, an innovative “catch share” program that allocates shares of the annual harvest to individual fishermen or vessels. The owner of the individual quota can sell his quota to another person permanently or lease his quota to another person temporarily. When fishermen have a fixed share of the annual harvest, they are able to fish when it is best for them, taking into consideration the market, weather conditions, and other factors. This slows the pace of the fishery, making harvesting surfclams safer, more efficient, profitable, and environmentally friendly—a win-win for the fishermen and the surfclam resource.

Not only does the surfclam fishery operate sustainably, but surfclams also offer little waste—two-thirds of the surf clam’s shucked weight is used, and its nectar is a delicacy. Also, some of the shell is used crushed in construction, or whole as containers for stuffed dishes.

Looking Ahead

A number of species of algae live in marine waters, and under the right conditions, can multiply and form blooms. Algal blooms have different impacts. Most are harmless, but 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.

 
 
 

LOCATION & HABITAT

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.

Juveniles burrow in medium- to fine-grain, low organic sands in waters 30 to 80 feet deep; adults prefer medium- to coarse-grain sand and gravel from beach zones to over 160 feet deep. They prefer more turbulent waters and bury themselves just below the sediment surface.

 
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BIOLOGY

Surfclams can live up to 35 years. On average, surfclams living in open water live longer than those living inshore. Growth rates depend on water temperature—southern surfclam populations in warmer water grow more slowly than the more northern populations. In general, surfclams grow fast, reaching a harvestable size of about 5 inches in 5 to 7 years. 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.

 
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PHYSICAL DESCRIPTION

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

 
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OVERVIEW

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.

 
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POPULATION STATUS

The most recent stock assessment for surfclams (2013) found that the stock is abundant. The stock is estimated to be 9 percent above its target population level. Biomass increased from 2,932 million pounds of meats and peaked at 5,512 million pounds of meats between 1982 and 1988. During 1989-2011, biomass declined at a rate of about 3.5 percent per year. Stock biomass during 2011 was 2,337 million pounds of meats, which was slightly less than the 2,425 million pounds of meats during 2010.

 
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ADDITIONAL RESEARCH

 
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Harvesting surfclams

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. The bars are spaced to allow smaller clams to fall out.

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Management

Who’s in charge? NOAA Fisheries, the Mid-Atlantic Fishery Management Council, and state resource management agencies

Current management:
Federal waters (3 to 200 miles offshore): Surfclam-Ocean Quahog Fishery Management Plan disclaimer.

  • Fishermen must have a permit to harvest surfclams.
  • Individual transferable quota system – managers set an annual harvest quota for federal waters and allocate it among individual fishermen or vessel owners. These quotas can be sold or leased.
  • Surfclams must be a minimum length of 4.75 inches; however, managers consider this size limit every year and may suspend it depending on changes in the population or other fishery management measures. The minimum size has been suspended for many years including 2013.
  • A number of areas are closed to the harvesting of surfclams, either due to environmental degradation or to toxins that cause paralytic shellfish poisoning (PSP).
  • Mandatory vessel monitoring systems monitor closed areas and borders between state and federal jurisdiction.
  • Fishermen must maintain and submit logbooks of each fishing trip to document catch.
  • Fishermen harvesting surfclams from Georges Bank have additional requirements under the PSP testing protocol.

State waters (within 3 miles of shore): Surfclams support valuable fisheries in New Jersey disclaimer and New York disclaimer state waters; state authorities are responsible for managing these fisheries.

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Annual Harvest

The quota for surfclams has remained constant since 2004, while the annual harvest has ranged from 61 percent to 95 percent of the quota over the period. The harvest from year to year may vary because of many factors, but is primarily a result of changes in market demand for clam products. Over 41 million pounds of surfclam meats were harvested in 2012 in both state and federal waters, a decrease of approximately 2.7 million pounds from 2011. New Jersey led with 20.5 million pounds, followed by Massachusetts with 18.2 million pounds and Maryland with 1.9 million pounds.

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Economy

The United States is the only source of Atlantic surfclams. Total revenues for the surfclam fishery were about $30 million in 2012, an increase of more than $380,000 from 2011. The average ex-vessel price (price fishermen receive) per pound of meats was $0.73  in 2012.

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OVERVIEW

The largest bivalves in the western North Atlantic, surfclams are too big and too coarse to be eaten whole like other clams. They’re sold processed, rather than live, in fresh, frozen, and canned products such as breaded clam strips, minced clams, stuffed clams, chowders, and broth. Canned clams should be in clear to opaque liquid. Breading should be intact on breaded product.

The raw meat is whitish-orange; cooked meat ranges from ivory to golden yellow, with some dark areas. Surfclams are less flavorful than hardshells. When cooked, the chewy white meat is mild and sweet.

Processing surfclams produces little waste: two-thirds of the surf clam’s shucked weight is used. Half of that is the “tongue,” used primarily for fried clam strips. The other half is the meat that runs around the shell, plus the twin adductor muscles (white cylinders attached to the shell) that open and close the shell. The adductor muscles are ground or chopped and used for chowders, bisques, and sauces. Shells serve as containers for stuffed dishes, and the clam nectar is delicious. (Seafood Business, 2011) disclaimer

 
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SEASONAL AVAILABILITY

Year-round.

 
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NUTRITION

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

Servings 1
Serving Weight 100 g
Calories 74
Protein 12.77 g
Fat, total 0.97 g
Saturated fatty acids, total 0.094 g
Carbohydrate 2.57 g
Sugars, total 0 g
Fiber, total dietary 0 g
Cholesterol 34 mg
Selenium 24.3 mcg
Sodium 56 mg

Atlantic Surfclam Table of Nutrition

 
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RECIPES

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