In 2006 the Southern Indian Ocean Deepsea Fishers Association was formed by four companies active in the deep-sea high seas fisheries of the Southern Indian Ocean where they have operated since prior to the year 2000. The Association was formed to promote responsible management of the deepwater fishery resources of the SIO to ensure sustained harvests to provide food, livelihoods and create wealth and to ensure conservation of biodiversity, especially deepwater benthos, in the area of the fishery.

The Association’s vessels operate on the high seas in sea depths from 500 to 1200m. In almost all cases, fishing operations are undertaken exclusively by benthopelagic trawling. This requires highly targeted fishing using complex acoustical equipment. Fishing is associated with bottom features such as ridges, knolls, hills and seamounts. 

The gear is only set when fish aggregations are located in an area where fishing operations are possible. As such, Fishing may be ‘mid-water’, in which case the trawl is fished in close association with, but may not contact, the sea floor. When ‘bottom’ fishing is undertaken, contact with the sea floor may continue from a few minutes up to 20 minutes. Most areas of sea features cannot be fished because of their rough topography: on some features there may be only one place fishing is possible along a well defined towing lane.