Unclear what the black patch is - perhaps a type of jellyfish that has collidedwith the bottom.
4/9/2019 2:26:46 PM
Date: 20130816T162931Z
Credit: NOAA OKEANOS Explorer Program , 2013 Northeast U. S. Canyons Expedition
Location: Between Alvin and Nantucket Canyons, 896-778m