Commercial krill fishing has been undertaken in the Southern Ocean for twenty years. Recently the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) introduced a reporting scheme to summarize catch data from half degree of latitude by one degree of longitude rectangles. These data demonstrate that commercial fishing in the southwest Atlantic is concentrated in the shelf zone. Certain krill predators are also restricted to this area whilst collecting food for their young during the summer. Krill fishing takes place year round, moving northwards in winter as the ice edge advances.