Image courtesy of the NOAA Office of Ocean Exploration and Research, Northeast U.S. Canyons Expedition 2013.
A boulder encrusted with biology – anemones and corals. Note the variety of rock sizes in the depression or moat around the boulder; these rocks may be dropstones, which reached the seafloor thousands of years ago as icebergs (products of the last continental ice sheet) floating at the surface melted and released them. The depression around the boulder is caused by currents sweeping along the seafloor and provides habitat for a variety of organisms such as fish, crabs, and shrimp. Download image (jpg, 76.0 KB).