200 metre depth contour
The 200 m depth contour is the water depth that is taken as the edge of the continental shelf. Beyond this depth the shelf usually steepens dramatically as the sea bed falls away to the ocean floor. The water column above this depth contour is often the focus of fishing as it is an area rich in nutrients that have risen up from the ocean depths.
The 200m contour is derived from GEBCO 30 arc-second bathymetry raster grid.