Submarine canyons, particularly in northern South Africa and northern Mozambique (Parson and Evans 2005, Green 2011), are also a common feature at the shelf edge and upper slope. Estimates of continental shelf areas of the WIO to the 200 m depth contour, ie FAO Area 51. It is now thought that the majority of these features do not actively transfer sediment to the adjacent deep ocean basin (Green and others, 2008). There are few available studies on shelf sediment distribution patterns in the WIO, qualitative reference is made to muddy sediments off river mouths, such as on the Sofala Bank in Mozambique, and Malindi-Ungwana Bay in Kenya (Munga and others, 2013). Detailed studies have been confined to the east coast of South Africa, and were undertaken by Flemming and Hay (1988) and Bosnian and others (2007), surface sediment distributions described in the latter have been recently improved and expanded by Green and MacKay (in press) and Figure 8.3 below.