,, - Atlantic Shellfish QL 626 U52 No 4 1985 Underwater World Atlantic Shellfish fishermen, processors and distributors. Atlantic hellfish are aquatic animals which Canada's Atlantic shellfish generate Slack a backbone and whose soft about half of fishermen's total income Shellfish bodies are usually enclosed in a protec- from the fisheries although they make tive outer shell. Sorne of them such as up less than one-fifth of total landings. lobsters and crabs are covered with a Major Canadian Atlantic shellfish in hard but jointed and flexible shell and usual order of economic importance are classed as crustaceans. Others like are: lobsters, scallops, snow crab, oysters and clams are called mol/uses shrimp, squid, clams and oysters. (a word from the Latin meaning soft- bodied). Afew molluscs such as octo- pus and squid do not have the outer shell but instead have a remnant of it inside their bodies. Shellfish are among the most popular of all seafood species and though harvests are limited in quantity, they contribute significantly to incomes of American Lobster from .23 to .91 kg. Giant lobsters can Lobster American Lobsters, widely acclaimed exceed 20 kg. (Homarus americanus) for their delicious meat, are truly kings Lobsters are found ail along the of Canadian shellfish. Their shell- North American east coast from armoured body is divided into two Labrador to the state of North main sections, the combined head and Carolina. They are most abundant in thorax, and the six-jointed abdomen the central part of this range, and the commonly called the "tail". There are inshore waters of Canada's Atlantic two pairs of antennae, a complicated provinces provide the greatest supply set of mouth parts, and two black eyes of lobsters to be found anywhere in mounted on short movable stalks set North America. A sizable offshore on either side of a stout, spiny horn. population also exists off the south- The body rests on four pairs of western coast of Nova Scotia and on spindly, jointed walking legs, the first Georges Bank. two pairs of which have small claws. Licensed Canadian fishermen har- Two large front legs provide the lobster vest inshore lobsters during the open with formidable tools for capturing season in their area, usually in the food. They are well-armed with strong warm months of the year, although the claws generously equipped with teeth open season in certain regions of New and sharp spines. Usually, one claw is Brunswick and Nova Scotia is from considerably heavier and is known as November to June or July. They use the "crusher" in contrast to the other, small boats to fish with baited, more slender "pincer". There is a wooden-frame traps or pots which are series of small paddles or swimmerets weighted and lowered to the sea bot- on the underside of the abdomen, tom. The traps are hauled by ropes which ends in a wide, flattened tail fan. attached to brightly-painted buoys The shell is often speckled with dark which mark their location. spots and varies in colour with the area There is also a small fleet of offshore of habitat, ranging from greenish blue lobster vessels. They use oversize traps to reddish brown. Lobsters are great because of the larger lobsters and are scavengers and live chiefly on fish not permitted to fish doser than 80 km (dead or alive) and immobile or slow- from shore. moving invertebrates such as mussels, More than half of the annual lobster sea urchins, crabs and worms which in- catch is shipped live to markets in other habit the sea bottom. Lobsters in the parts of Canada, the United States and commercial catch generally range in Europe. The remainder is sold as fresh- length from 18 to 30 cm and in weight cooked, frozen or canned lobster meat. Underwater World 2 AOU 12 1993 Sea Scallops Important Canadian sea scallop Sea Scallop Sea scallops, also called giant or fisheries are conducted by inshore (Placopecten magellanicus) smooth scallops, are the most impor- fishermen in the Gulf of St. Lawrence tant commercial species of molluscan and the Bay of Fundy off Digby, Nova shellfish in Canada. Scotia. The offshore fishery occurs on These shellfish are bivalves, that is, Georges Bank off the southwestern tip they have two round valves or shells, of Nova Scotia. Depending on the held together by a small straight hinge. area, scallop fishing can be conducted The lower valve is flat, smooth and on a year-round basis. white or cream in colour, while the Fishermen harvesting inshore sea upper one is arched slightly and usually scallops use vessels of about 18 m reddish brown. The shell size in which tow drags equipped with large commercial catches ranges from 15 to wire-mesh bags over the ocean bottom. 20 cm in diameter. Larger, more powerful vessels (about Between the shells are the soft body 30 m in length) are used to harvest the parts which account for about 40 per offshore scallops. cent of a scallop's total weight. The Scallops are shelled or "shucked" as large white muscle in the centre which soon as they are caught. Most Cana- opens and closes the shells is called the dian-landed scallops are sold in the "meat" and is the only part of the sea United States where they are marketed scallop eaten in Canada. fresh or frozen, or as breaded and Unlike most other shelled molluscs, partially fried products. scallops can swim. If disturbed by fishing operations, for example, scallops will contract their powerful muscle and 'clap' the shells together. This movement forces water out from the corners of the hinge, propelling them forward. If left relatively undisturbed, how- ever, scallops generally remain seden- tary and lie with the flattened shell on firm gravel, shells or rocks on the ocean floor. Where food and tempera- ture conditions are most favourable for survival, sea scallops occur in dense local populations called "beds". Scallops feed on minute plants and anirnals which they strain from the water by an elaborate filter mechanism involving the gills. Sea scallops are found in the north- west Atlantic from the northern part of the Gulf of St. Lawrence to the coastal waters of North Carolina in the United States. In the northern part of this range, they occur in shallow water (less than 18 m) while in the southern por- tion, they are found in water deeper than 55 m. 3 Underwater World Atlantic Snow Crab Atlantic Snow Crab are commonly found on the muddy or (Chionoecetes opilio) Atlantic snow crabs are crustaceans sandy sea floor at 75-450 m. and belong to the family of spider Snow crabs occur in the northwest crabs, so-called because their legs are Atlantic from Greenland down the long and slender in proportion to their Canadian Atlantic coast and into the rounded bodies. Canadian fishermen Gulf of Maine. ln Canadian waters, originally marketed this species under they are most abundant off Labrador, the trade name of queen crab. Newfoundland and in the Gulf of St. The Canadian fishery for these Lawrence. ln the Gulf, snow crabs are shellfish began in 1967 after explora- landed from May through September tory fishing efforts found abundant and in some areas off Newfoundland stocks in the Gulf of St. Lawrence. and Labrador, year-round fishing is Since that time, the fishery has possible when ice conditions permit. developed rapidly and snow crabs rank Fishermen harvest snow crabs in the with lobster and salmon among Atlantic Gulf of St. Lawrence from 16-18 m Canada's top taste treats in fishery boats which have been converted from products. gillnetting, seining or dragging for Snow crabs have a flattened, almost groundfish. Each boat works about circular body and five pairs of long, 35-80 square steel-frame traps. These spider-like legs, one pair of which is traps are baited, set singly and hauled equipped with strong claws. The upper daily by ropes which lead to surface surface of the shell is orangey tan and buoys. The crabs are stored alive on ice the underneath is creamy white. When in the boat's hold. In the deeper waters fully mature, male crabs are twice as of Newfoundland's bays (over 185 m), large as females and average about small conical traps are used from 13 cm across the body shell. Average smaller boats. These are set together in weight of these crabs in the commercial lines of about IO traps each. catch is . 7 kg. In Canadian waters, they A gourmet food item, snow crab meat is marketed in Canada, the United States and Europe as cooked frozen meat and canned meat. Underwater World 4 Shrimp Pink shrimp in North American Pink Shrimp Shrimp are crustaceans closely waters range from the Columbia River (Pandelus borealis) related to lobsters and crayfish. The on the Pacifie coast, along the Arctic Atlantic shrimp fisheries mainly coast and south to Massachusetts Bay harvest pink shrimp, also known as on the Atlantic coast. Canadian northern pink shrimp and great nor- harvests on the Atlantic coast take thern prawn. Continuing high world place mainly in the Gulf of St. Law- market demand is reflected in the rence, on the Scotian Shelf, and along growing importance of Canada's the coast of Labrador. eastern shrimp fishery. The most common method of shrimp Small, spindly, long-bodied animais, fishing involves the use of otter trawls. of pinky-red colouring, pink shrimp Shrimp are usually cooked fairly average 7.4 to IO cm in length. It takes soon after capture, and are principally approximately 120 to 130 of them to marketed as headless, cooked and make l kg.