Few humans permanently inhabit the land masses of the Southern Ocean*, and all too often their brief visits have severely impacted the animals which depend on the ocean for their survival. Since the 18th century, when humans began hunting in the Southern Ocean, many species have nearly been exterminated by commercial exploitation. A number of others have been reduced to low levels, while uncontrolled exploitation is making inroads into the remainder.

^*  For the purposes of this review, the Southern Ocean is taken to be the area of application (i.e. south of about 50°S) of the Convention Area of Antarctic Marine Living Resources (CCAMLR).

Fur seals were the first hunted and when these became scarce, elephant seals were harvested for their oil. Other seals were taken, though in smaller numbers, for dog food or by sealers searching for new stocks to exploit.

Shore-based commercial whaling began at South Georgia in 1904. With the arrival of factory vessels in the 1920s, whaling ships moved into deeper water offshore to exploit fin and other whale species found there. More than 1.5 million animals were killed by the time the League of Nations took the first steps to protect whales in the 1930s. The International Whaling Commission (IWC) was established in 1946 to regulate whaling and the exploitation of the major whale species was gradually banned in turn (http://ourworld.compuserve.com/ homepages/iwcoffice/newpage6.htm). The last commercial whaling season was in 1986/87, and in 1994 the IWC declared much of the Southern Ocean a whale sanctuary.

Even birds were not exempt from being hunted. In the 20th century, large numbers of penguins were killed for oil, food and fuel. The eggs of these and other bird species were also harvested.

Large-scale commercial exploitation of fish did not commence until the 1970s and soon expanded rapidly. Trawlers first targeted nototheniids, lanternfish and icefish for human consumption and fish meal. Longliners arrived in the mid-1980s to catch Patagonian toothfish (Dissostichus eleginoides) and, inadvertently, albatrosses and petrels drowned when trying to take bait from longline hooks. By mid-1997, some 3.2 million tonnes of finfish had been taken from the Southern Ocean.

Fishing exhibited a similar pattern to that of sealing and whaling – discovery, full-scale exploitation and rapid depletion of stocks, followed by a switch to other stocks or species. By the end of the 1980s, CCAMLR had prohibited fishing for most finfish species or had imposed strict catch limits (see below). However, high levels of illegal, unregulated and unreported (IUU) fishing for Patagonian toothfish have caused considerable international concern in recent years.

Fishing for krill (Euphausia superba) began in the early 1970s amidst much concern that this would impact negatively on the entire Antarctic marine ecosystem. The cause for such concern rested with krill’s role as the main food item of many Antarctic whale, seal, bird and fish species (see diagram). Krill also contribute to making the seasonal pack-ice zone the most productive in Antarctica. Krill catches peaked at more than 500 000 tonnes in 1981/82 with the bulk of the catch being processed for animal feed. Krill are now largely used for aquaculture feed, bait and human consumption. After the large Soviet fleet ceased fishing in the early 1990s, the krill catch dropped dramatically. Nevertheless, an estimated 5.74 million tonnes have been taken to date. The current krill catch is slightly in excess of 100 000 tonnes per year.

A small exploratory fishery for stone crabs (Lithodes murrayi) was initiated in 1992/93, but this did not prove to be economically viable.

Large squid fisheries are located just north of the CCAMLR boundary. One of the target species, Martialia hyadesi, is also found within the CCAMLR Convention Area. The current CCAMLR catch limit for squid is 2 500 tonnes per year.