Submarine canyons – Submarine canyons are defined as “steep-walled, sinuous valleys with V-shaped cross sections, axes sloping outward as continuously as river-cut land canyons and relief comparable to even the largest of land canyons” (Shepard, 1963). “Large” canyons were mapped in this study based on the definition of Harris and Whiteway (2011), which requires canyons to extend over a depth range of at least 1,000 m and to be incised at least 100 m into the slope at some point along their thalweg.
Submarine canyons are diverse and complex in terms of their origins, hydrography, geologic settings and biodiversity. The combination of steep rocky slopes, strong currents and enhanced access to food makes submarine canyons places of special ecological significance. Canyons often are iconic, defining features of marine reserves in many locations because of their association with higher biomass and biodiversity. For example, the La Jolla Canyon off southern California has been shown to have as much as 50 times the biomass than surrounding areas of shelf and slope (Vetter and Dayton, 1998).