![]() ![]() "We built a small dredge fitted with four 11-inch hollow hemispheres positioned close to the seabed and mounted on pivots so that if they hit something they could deflect up out of the way," says Goudey. ![]() The most promising results were implemented in a prototype dredge. So Goudey experimented with devices of different shapes and sizes to see how they affected scallop shells placed on the bottom of MIT's towing tank. The best option for that, he decided, was to use jets of water. Goudey figured that would require disturbing or lifting the scallops, in preparation for the chain bag, without physically contacting the ground. Is there a way to catch scallops without leveling the bottom in front of the dredge? But along with the scallops, says Goudey, other organisms living on and buried just below the surface can get caught or damaged. However, on a more typical sea bottom with sand waves or humps and valleys, the cutting bar levels the bottom so that the chain bag can scoop up scallops in its path. The dredge includes a cutting bar, which has little effect on a perfectly level bottom. The standard dredge used to harvest scallops consists of a heavy steel towing frame and a chain bag that drags along the sea floor behind the frame. What current dredges don't do, says Goudey, is take into consideration unintended consequences, such as damaging bottom habitat - a concern since the 1986 reauthorization of the Magnuson-Stevens Act introduced the issue of essential fish habitat. The director of MIT Sea Grant's Center for Fisheries Engineering Research wants to build a better dredge-even though he's the first to admit that current dredges do a fine job of catching the creatures. CAMBRIDGE, Mass.-Cliff Goudey's version of the better mousetrap is the better scallop dredge. ![]()
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