A combination of novel robot technology and ship-based measurements has allowed the National Oceanographic Centre (NOC) to create a 3D map of the only deep-water conservation zone in England (1). The image depicting Whittard Canyon in the Bay of Biscay constitutes the first 3D picture of a submarine canyon habitat (2).
Although subsea mapping techniques used in the past could not provide great detail, the maps created by the NOC can be scaled to display the entire 200 km canyon or a single coral polyp (1,3). Four technologies were used by the NOC to obtain this breadth and depth, known as a ‘nested map’ due to the resulting layers of data and images (1). These technologies included echo-sounders, an autonomous Autosub6000 robot-sub, a remotely controlled vehicle known as Isis, and a Seaglider robot which was borrowed from the University of East Anglia (2).
A map of the canyon with 50m pixel resolution was created with echo-sounders aboard the research vessel (1). The Autosub6000, a second echo-sounder with a novel sideways direction, mapped the vertical walls of the canyon with a resolution of 3-5m per pixel. Isis collected biological and geological samples as well as the record high definition video at a resolution of 10-20 cm (2). Physical aspects of the water column such as temperature, salinity, and turbidity were measured by the Seaglider (2). Funding for these technologies as well as the expedition itself was provided by the CODEMAP project, the NERC MARMARE program, and DERFA (1).
The map revealed that the Whittard Canyon is 4,000m deep and has strong internal tidal flows that deliver plumes of organic-rich sediment to the habitat (1, 2). According to Tahmeena Aslam, who was responsible for the Seaglider, these processes likely have a “major influence on the distribution of habitats and fauna within the canyon” (1). The expedition, which set sail on August 9th, imaged footage of unique biodiversity, including cold-water corals, clams, deep-sea oysters, as well as blue sharks and swordfish (2, 3). In addition to rich faunal distribution, the canyon also contains unique morphology (3).
Dr. Veerle Huvenne, who led the 5-week NOC expedition, said “We have mapped cliffs up to 150m high and 1.6km long, in some locations down to centimetre-scale resolution. This makes us the only group in the world who currently can image vertical cliffs in the deep sea in this way” (3).
Submarine canyons can be as deep as the Grand Canyon and rich with nutrients, making them one of the most undiscovered hot-spots for biodiversity (2). The results from this research will lead to a better understanding of the ecology and biodiversity of the Whittard Canyon, and the technological methods used to create this map will allow researchers around the world discover more about these underwater valleys and the secrets they may hold.
1. National Oceanography Centre. (2015, September 16). Robots help to map England’s only deep-water Marine Conservation Zone. ScienceDaily. Retrieved from www.sciencedaily.com/releases/2015/09/150916113052.htm
2. Robots help create 3D map of subsea canyon. (2015, September 17). Retrieved from http://www.theengineer.co.uk/news/robots-help-create-3d-map-of-subsea-canyon/1021078.article