The fishery for North Atlantic sea scallops, which are found from Newfoundland to North Carolina, is the largest scallop fishery in the world. Canadian and U.S. fishermen land about 30,000 metric tons of sea scallop meats a year, with about 90 percent of the catch coming from the U.S. fleet.
About half of the U.S. catch is landed by the New Bedford, Mass. fleet. Scallopers based out of New Jersey and Virginia land most of the rest of the catch. In Canada, boats fishing out of Nova Scotia land almost all the sea scallop catch. Sea scallops are fished year-round, but landings are heaviest from May to September. Boats using dredges catch more than 99 percent of the sea scallop landings. Divers catch a handful of sea scallops in Maine.
In the U.S., only the adductor muscle, which scallops use to hold their shells together, is eaten. Depending on the time of year, the adductor muscle can account for 10-15 percent of the animal’s total weight. In Europe, sea scallops are often served with the roe attached to the adductor muscle, while in Asia the whole animal – muscle, mantle and roe – is usually eaten.
Atlantic sea scallops can grow to a width of eight inches and the adductor can be almost two inches in diameter. Fresh sea scallops are sold ungraded by fishermen in 50-pound linen sacks to processors. Processors, in turn, wash them and grade them, typically U-10, 10-20, 20-30 and 30-40 count per pound.
Based on the customer spec, processors may also soak the scallop meats in sodium tripolyphosphate, an additive that is widely used in the food industry. Depending on the length of the soak and the amount of sodium tripolyphosphate used, the weight of the scallop meat can be increased as much as 20 or 30 percent.
The amount of water added to scallop meats has long been a contentious and confusing issue for scallop buyers. Although a scallop’s moisture content will change depending on the time of year, the moisture content of a sea scallop meat is typically in the range of 75-80 percent water. In the 1990s, the FDA issued a labeling policy that scallops with a moisture content of 80 to 84 percent had to be labeled “Water Added Scallop Product.” A scallop with a moisture content higher than 84 percent was considered “adulterated” by the FDA.
In 2004, however, the FDA abandoned this labeling policy, although processors who treat their scallop meats with sodium tripolyphosphate must still state that on their label. The U.S Department of Commerce, which operates a voluntary seafood inspection program, requires any scallop meats with a moisture content higher than 83 percent to be labeled that they have been treated with sodium tripolyphosphate. In Canada, it is illegal to treat scallops with sodium tripolyphosphate.
Scallops that have not been soaked are normally marketed as “dry” scallops, while treated scallops are usually marketed as “processed” scallops. The term “diver scallop” is often used to indicate a scallop that has not been treated, although most of the scallops sold as diver scallops were fished using a dredge.
The meat of a dry scallop should be firm and mildly translucent with an ivory color, not bright white – a sign the scallop was treated. If the liquid that drains from the scallop is soapy or foamy, this is a sign of excessive soaking.
A slight mottling or pinkish-orange coloration means that roe has discolored the scallop meat. This is purely cosmetic and does not affect the eating quality of the meat.