Thursday, 4:30 PM
MIT develops a kinder scallop dredge
(Massachusetts Institute of Technology)
By Andrew Ryan, Globe Staff
Cliff Goudey, a research engineer at the Massachusetts Institute of Technology, is almost a Thomas Edison of the sea, inventing algae vacuums, tangle-free buoys, and fish farms that drift in the deep waters of the Gulf Stream.
Now Goudey has developed what MIT described as a “kinder, gentler” scallop dredge, sucking up the succulent mollusks without tearing up the ocean floor.
Traditional scallop dredges use heavy steel bars to plow through ridges on the bottom of the sea, a process some critics compare to clear cut mining. Goudey’s new device shoots jets of water into the sand, minimizing the impact on marine life.
"The scallops get flipped up and start spinning high enough so they are suspended in the water" and get caught by a chain sack, said Goudey, director of the MIT Sea Grant Center for Fisheries Engineering Research.
In additional to being gentler on ocean habitats, the new scallop catcher is also expected to be much more durable than the traditional dredges, which are quickly ground down by sand and gravel on the sea floor.
The newfangled scallop catcher is unique in several ways. First, it skids along the bottom on wheels instead of metal pads that are hallmarks of traditional dredges. The pads wear out and can hurt marine life, Goudey said.
Even more important are the series of bowl-shaped spheres that force streams of water into the sand when the device is dragged along the ocean floor. Water shoots down off the bowls like air off the wing of a plane, creating enough pressure to free scallops from their hiding places.
A prototype was tested successfully on Stellwagen Bank off the coast of Massachusetts and in European waters off the Isle of Man. The apparatus caught about 50 to 60 percent of what is typically hauled in by a traditional scallop dredge, a rate Goudey hopes to improve.
"We believe that with a little adjusting," he said, "that catch rate could become competitive."
