Antarctic

The Antarctic terrestrial ecosystem is structurally simplistic with a small number of species. Marine biomass in the Southern Ocean can be immense but species richness is generally low (Wynn Williams 1996). The benthic (bottom) fish fauna of the continental and upper slope of Antarctica includes 213 species confined to 18 families (Eastman 2000). Seals, whales and seabirds dominate the higher levels of the Southern Ocean. Knowledge of Southern Ocean marine diversity is confined largely to the continental shelves and slopes. Little is known about the fauna of the deep sea around Antarctica.

Historic sealing and whaling activities have had a significant impact on these populations in the Southern Ocean, at one point threatening extinction of some species. Today, strict international agreements govern the harvesting of Antarctic seals (Convention for the Conservation of Antarctic Seals) and whales (International Whaling Convention, which also designated large areas of the Southern Ocean as a whale sanctuary). Only limited numbers of seals are taken for scientific purposes, while approximately 440 minke whales are killed each year.

Protected areas in the Arctic
	Number of areas	Total area (km2)	% of country's Arctic land area
Canada	61	500 842	9.5
Finland	54	24 530	30.8
Greenland	15	993 070	45.6
Iceland*	24	12 397	12.0
Norway**	39	41 380	25.3
Russian Federation*	110	625 518	9.9
Sweden	47	21 707	22.8
United States (Alaska)	55	296 499	50.2
Total	405	2 505 943	17.0
Notes: * large marine components are included; ** most of the area protected is in Svalbord, only about 7 per cent of the Arctic mainland is protected Source: CAFF 2001

Fish and krill (tiny planktonic crustaceans) are now primarily the targets of human exploitation in the Southern Ocean. From 1969-70, when records of commercial fishing began, to the end of 1998, a total of 8 739 800 tonnes of krill and fish had been taken from the Southern Ocean (CCAMLR 2000a). In 1982, the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) was established to promote the conservation and rational use of marine living resources south of the Antarctic Convergence. Southern Ocean fisheries are now managed within the framework of CCAMLR.

Although there is uncertainty in its assessments, CCAMLR estimates that the level of illegal, unregulated and unreported (IUU) fishing in the Southern Ocean - which has been a major problem for decades - had decreased in 1998 but has since increased despite stronger CCAMLR measures to combat IUU fishing. The high level of illegal catch of Patagonian toothfish (Dissostichus eleginoides) in the South Indian Ocean has become a major concern as it threatens the sustainability of stocks (CCAMLR 2000a). To address IUU catches, CCAMLR adopted a Catch Documentation Scheme requiring all landings, trans-shipments and importations of toothfish into the territories of contracting parties to be accompanied by a completed catch document. In 2000, CCAMLR took further steps to combat IUU fishing by urging all parties to avoid flagging or licensing vessels with a history of engagement in illegal practices (CCAMLR 2000b).

CCAMLR regulation has reduced the incidental bycatch of seabirds and marine mammals in legal fisheries to low levels but illegal fishing still takes its toll. For some seabird populations, long-line fisheries represent a major threat. This led to the listing in 1997 of all albatross species on the protected species list of the CMS. Albatross and petrel species, such as the wandering albatross (Diomedea exulans) and the Antarctic giant petrel (Macronectes giganteus), have also been listed as vulnerable in the IUCN Red List (Hilton-Taylor 2000). The final draft of the Agreement on the Conservation of Albatross and Petrels was recently completed in Cape Town, South Africa.

Changes to the distribution and composition of terrestrial flora and fauna, attributable to recent warming over Antarctica, have been observed over the past three decades. Composition and distribution of marine species is also expected to change with a changing climate. It has been indicated that the marked increase in the number of Adelie penguins (Pygoscelis adeliae) in the Ross Sea area in the 1980s showed remarkable synchronization with the climatic variation in the same region (Taylor and Wilson 1990, Blackburn and others 1990). At Palmer Station on Anvers Island, where Adelie penguins are known to have nested only prior to the 1950s, gentoo and chinstrap penguins are now breeding and have expanded their ranges southward in the Peninsula within the past 50 years, in correlation with pronounced regional warming (Emslie and others 1998).

Changes in the extent and thickness of ice affect the timing, magnitude and duration of the seasonal pulse of primary production in the polar regions. It has been suggested that sea ice extent affects krill availability which in turn may affect krill predators. Regional warming and reduced krill abundance may therefore affect the marine food web (Loeb and others 1997). The density and abundance of minke whales has been observed to be lower in seasons with warmer sea surface temperatures, fewer cold-water intrusions, and smaller sea ice extent, possibly owing to the shift in availability of prey (Kasamatsu 2000).

Along the west coast of the Antarctic Peninsula, springtime ozone depletion can lead to a twofold increase in biologically effective UV-B radiation (Day and others 1999). UV exposure affects phytoplankton, including inhibition of primary production. This is a major concern in view of the phytoplankton's key role in the short food chain of the Antarctic marine ecosystem. The spring bloom of phytoplankton coincides with the springtime ozone hole and the subsequent period of high UV-B radiation. Reduction of phytoplanktonic production associated with the ozone hole is estimated to be 6-12 per cent (Smith and others 1992).