Submarine canyons are considered the main pathways between the shelf and the deep sea, funnelling sediments in sometimes catastrophic flows, while also transporting pollutants and litter from shallow to deep waters. Their steep morphology has a strong influence on the local oceanography and current patterns, causing the formation of large internal tides, upwelling and enhanced surface primary productivity. These processes, together with the high terrain heterogeneity, often result in high biodiversity, which means that submarine canyons are generally considered biodiversity hotspots.
Still, the various processes acting in submarine canyons are poorly understood. Their extreme morphology makes them challenging and inaccessible locations for study. Thanks to recent technological developments, especially in marine robotics, we now can start to build a picture of true canyon morphology, current regimes, sediment transport processes and habitat distribution. This presentation will demonstrate a new approach to habitat mapping in submarine canyons, developed at the National Oceanography Centre, Southampton, and applied to the Whittard Canyon in the Bay of Biscay, NE Atlantic. Making simulteaneous use of an AUV, ROV and a Seaglider, we could observe all submarine canyon processes at the scale they occur, while also imaging the morphology and faunal patterns of near-vertical and overhanging walls, locations that until recently had stayed out of sight and out of mind.