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Quahog

By Eleanor Ely
P1123

The shellfish that Rhode Islanders call a quahog possesses an impressive variety of names, and even the word "quahog" (which comes from the Narragansett Indian name "poquauhock") has an alternate spelling, "quahaug," and a number of pronunciations: KO-hog, KWO-hog, and KWA-hog. The quahog's scientific name, Mercenaria mercenaria, is derived from a Latin word meaning "wages" and was chosen because Indians used quahog shells to make beads that were used as money (called wampum). In much of the United States, quahogs are simply called "hard clams" or "hard-shell clams."

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Quahogs live buried just below the surface in the bottom sand or mud, with their two siphons sticking up into the water.  Drawing by Steve Silvia.

Still other names are based on a quahog's size. Little necks (or "necks") are the smallest legal size, measuring 1 inch thick at the largest thickness; chowders are the largest size; and cherrystones are in between.

In Rhode Island, quahogs grow to legal size in 3 to 4 years if conditions are good. A quahog's age can be determined by counting the growth rings on its shell. As quahogs get older, they grow more slowly, so the growth rings get very close together and difficult to count accurately. Researchers estimate that the largest quahogs (4 inches or more in length) are as much as 40 years old.

Quahogs - like soft-shell clams, oysters, scallops, and mussels - are classified as bivalve mollusks because they have hinged shells made up of two halves, or "valves." Bivalves obtain their food by "filter feeding." Water is taken in through a siphon and passed over the gills, which are specially adapted to filter out food (microscopic algae and other small organic particles). The filtered water is then expelled via another siphon. A large clam can filter about a gallon of water in one hour.

Quahogs prefer salinities between 18 and 26 parts per thousand. This is less salty than the open ocean (salinity about 35 parts per thousand), so quahogs are often found in estuaries (like Narragansett Bay) where the mixing of fresh and salt water provides ideal conditions.

Although quahogs can be found along the North American Atlantic coast from Canada's Gulf of Saint Lawrence to Florida, they are particularly abundant between Cape Cod and New Jersey. Farther north, most waters are too cold for quahogs, restricting them to just a few relatively warm coves; while to the south, quahogs have more predators, such as blue crabs.

Rhode Island, situated right in the middle of "quahog country," has supplied a quarter of the nation's total annual commercial quahog catch. In 1987, the humble quahog was elevated to the status of Rhode Island's official state shell.

Commercial fishery


Today, the quahog is by far the most economically important resource harvested from Narragansett Bay. At the turn of the century, though, oysters dominated commercial shellfishing in the bay. But the oyster population gradually declined after the 1920s, and at the same time the quahog fishery expanded.

By the 1950s, two groups of quahoggers were competing for the resource in the bay. The dredgers, who used boats to drag metal dredges across the bottom, could harvest large numbers of clams much faster than could the handrakers, who used their own muscle power to harvest quahogs with bullrakes and tongs. The handrakers complained that the dredgers were wiping out the quahog population, damaging clams, and putting the handrakers out of work. Eventually the handrakers won out, and today dredging in Narragansett Bay is severely restricted.

Significantly improved bullrakes, capable of harvesting quahogs from as far down as 70 feet, appeared in the early 1970s. (Tongs and older bullrakes could only be used in shallower waters.) Following this development, Rhode Island quahog harvests increased steadily - from about 1 million pounds in the early 1970s to about 3.5 million in 1980 - and have remained in the vicinity of 3.5 to 4 million pounds per year ever since. In 1987, the catch was 3,349,334 pounds of meats, with a value of $15.6 million at the dock.

Pollution in Narragansett Bay affects the quahog industry because the filter-feeding process concentrates not only food particles but also many pollutants - including disease-causing bacteria and viruses, and toxic compounds. Thus, even pollutants that are present only in low levels in the water can accumulate to dangerous levels in filter feeders.

About 1/4 of Narragansett Bay's total area - including the Providence River and Mount Hope Bay - is permanently closed to shellfishing because of the danger of sewage contamination. In addition, a portion of the upper bay is closed after rainfalls because antiquated "combined sewage" systems in Providence and other towns allow inadequately treated sewage to enter the bay during rainstorms.

Digging your own quahogs


There is some risk associated with any meat or seafood that is eaten raw. To reduce the chance of contracting gastroenteritis, or possibly even more serious diseases like typhoid or hepatitis, take care to collect quahogs only from approved areas. Warning signs are posted in areas that are closed due to pollution, but vandals sometimes remove the signs.

Rhode Island's basic statewide catch limit is 1/2 bushel of quahogs per person per day. However, many places, classified as special shellfish management areas, have lower catch limits and, in some cases, specific opening and closing dates. These include all the coastal ponds, Greenwich Bay, upper Narragansett Bay, and many other areas. All the special management areas are listed in the leaflet Rhode Island Marine Fisheries Laws and Regulations," available in bait shops or town halls.

Out-of-staters need a license, obtainable at town halls and bait shops, to dig clams in Rhode Island.

For information about special management areas or closures due to pollution, call DEM at 401-222-6800, or view shellfish closure maps on-line.

In some parts of New England, it is also important to watch for shellfishing closures due to red tides. Shellfish taken from a red tide area can contain a toxin that causes paralytic shellfish poisoning. The toxin is not destroyed by cooking. However, no occurrences of red tide have been recorded in Narragansett Bay.

Quahogs are found in the top 3 inches of sandy or sand-and-mud bottoms, usually below the low-tide line. It's easier to dig for them at low tide.

Digging your own quahogs requires little or no equipment. One popular method is "treading": Simply probe the bottom with your foot until you feel a quahog, then reach down and pull it up with your hand. Alternatively, you may use a hand rake (available at hardware stores). A clam rake resembles a garden rake, but the tines are longer and the handle is shorter. Drag the rake through the bottom until you feel a scraping, then push the rake in deeper and pull it toward you and upwards to harvest the quahogs. Be sure to wear old shoes or sneakers to protect your feet.

Once you get the quahogs home, rinse them in cold water to remove sand and discard any that have opened (they are either dead or dying). They will keep up to a week in the refrigerator if they are unopened and laid on their sides.

Shucking (opening) quahogs can be frustrating, especially for the novice. Clams "relax" and become much easier to open if they are chilled, on ice or in the refrigerator, for several hours. To open a clam, hold it in your left hand (if you are right-handed) and use your right hand to work a special shucking knife (available at the housewares departments of most stores, or at many fish stores) into the space between the shells. As soon as the knife penetrates, slide it along the inside of one shell to cut the two adductor muscles). Open the clam and detach the meat by cutting the other side of the adductor muscle. The quahog is now ready to be served on the half shell, used in recipes, or frozen for later use. Quahogs make excellent chowder, clam cakes, stuffed clams, and clam sauce for pasta. However, they are too tough to make good steamed or fried clams.

Though purists would object, quahogs that are not going to be eaten raw may be steamed or placed in a microwave until they begin to open. These procedures make opening the clams much easier but they also slightly toughen the meats.

FOR FURTHER READING:

Olsen, Stephen, Donald D. Robadue, Jr and Virginia Lee. 1980. An Interpretive Atlas of Narragansett Bay. Rhode Island Sea Grant, Narragansett, Rl.

Ricciuti, Edward. 1982. Secrets of Shellfishing. Hancock Plouse, Killingworth, CT

Return to Rhode Island Sea Grant Fact Sheets

posted 4/98
updated 5/01