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Thus commercial harvesting in the Southern Ocean has continued for over two centuries.  Exploitation began in the late 18th and 19th centuries when Antarctic and Sub-Antarctic fur seals Arctocephalus gazella and A. tropicalis were harvested for their pelts.  This ceased only as the species neared extinction.  Subsequently in the middle to late 19th century, penguins and elephant seals Mirounga leonina were exploited for their oil, as were baleen whales Balaenoptera spp in the early 20th century.  The serial over-exploitation of the great whale species culminated in whaling (and with it sealing) becoming commercially unviable by the 1960s.  Harvesting then transferred to finfish and krill.  With the collapse of overfished icefish Champsocephalus gunnari stocks in the 1970s there was recognition that uncontrolled exploitation of species such as Antarctic krill would have an unprecedented effect upon the many species that were dependant upon it as a prey species, including the recovering stocks of previously harvested species such as whales, Antarctic fur seals and fin-fish. 

The Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) came into force in 1982, as part of the Antarctic Treaty System. It was established mainly in response to concerns that an increase in commercial krill catches in the Southern Ocean could have a serious impact on populations of krill and other marine life; particularly on seabirds, seals and fish, which mainly depend upon krill for food. Thus, the aim of the Convention is to conserve marine life in the Southern Ocean. However, conservation does not exclude harvesting if it is carried out in a rational manner.

CCAMLR was a pioneer in the development of what has become known as the ‘ecosystem approach’ to the management of marine fisheries. This methodology does not simply concentrate upon the target species fished, but also seeks to avoid situations whereby fisheries have a detrimental or adverse effect upon ‘dependent and related species’. CCAMLR therefore aspires to develop management approaches that assess the status of the ecosystem and its health.

CCAMLR has adopted a precautionary approach to management based on the considerable uncertainty associated with data collected in the vast tracts of the Antarctic, and particularly given the complexity of the underlying marine ecosystem.

CCAMLR has several approaches to regulate harvesting in the Southern Ocean and draws on five main data sources to improve management advice:

• fisheries catch and effort statistics;
• biological information and data on by-catches of fish in commercial fisheries;
• biological information and data on seabirds and marine mammals caught during commercial operations and collected by national and international scientific observers;
• biological information collected during scientific and fishery-independent surveys; and,
• biological information on krill and dependent species collected as part of the CCAMLR Ecosystem Monitoring Program.

Given the complexity and dynamics of the Southern Ocean, CCAMLR is still far from reaching its principal goals. However, CCAMLR has made important steps towards the development of an integrated approach to fisheries management and has, in many respects, been the fisheries organisation that has taken the lead in developing such approaches.

Threats to the Southern Ocean are mainly due to fishing practices.  The main threats are bycatch, illegal, unregulated, and unreported (IUU) fishing, and marine debris.  Longline fishing for toothfish has resulted in the bycatch of seabirds, especially albatrosses and petrels who try to steal bait from the lines, and of fish, such as skates and rays that are caught and killed or discarded.  Bycatch is also an issue for midwater trawlers that use fine-mesh nets, which may also catch larvae and juveniles.

         The threat posed by IUU activity to regulated toothfish fisheries is well documented (Agnew 2000, Constable et al 2000, CCAMLR 2003).  Despite initiatives to address the situation, especially the resolute policing of the main fishing grounds around sub-Antarctic Islands, only at South Georgia (and in the Ross Sea) are IUU catches currently at insignificant levels, although there is evidence of reduction in levels elsewhere, which may augur better for the future.  If not, many stocks of toothfish will soon become depleted to levels potentially prejudicial to their recovery. 

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