Science News - by scipa

"Trawling is the most widespread form of fishing. But bottom trawling is brutal. It uses an enormous, toothed bar mounted on a device called a dredge to scrape the seabed. Dredging throws the intended catch up into a cloud that is captured by a net trailing behind."

"The dredge has several hemispheric scoops in place of the toothed bar. As it is pulled along, the scoops direct water downward. That creates a series of gentle jets that can shuffle the scallops from their resting places—but the streams of water are not powerful enough to damage the benthic zone's long-term tenants. And the scoops swivel out of the way if they encounter anything solid, so the dredge does not destroy such protuberances. Best of all, from the fisherman's point of view, it takes less effort to float a dredge on water jets than it does to drag it across the uneven surface of the seabed. That makes Dr Goudey's new device a more fuel-efficient way to fish than the traditional method."