Deep-see Canyons Are Reshaped by Fish Trawling

Trawling is changing the topography and the environment of deep-sea canyons on the continental slope, a new study from the University of Barcelona finds.

The study, published in Nature, contends that marine mountainsides are looking more like plowed fields, which changes the habitats of deep-sea creatures. The process rivals landslides and storms for re-shaping the slopes.

Fishing fleets have been trawling the Mediterranean along the coast of Spain for years, dragging nets along the flat, shallow coastal sea floor. In the 1960?s, they started to pursue shrimp farther offshore and into rugged canyons up to 800 meters deep. Until now, the impact this trawling had on the rough canyon terrain was a mystery.

Geoscientists were surveying off the coast of Spain in 2006 when they found smooth slopes, which they attributed to an underwater cascade. The only problem was that one slope was smoothed in the lee of the supposed cascade.


http://www.redorbit.com/news/science/1112689366/trawling-deep-sea-090712/