Global Environment Outlook 3 (GEO 3)

1 4 6

STATE OF THE ENVIRONMENT AND POLICY RETROSPECTIVE: 1972–2002

Biodiversity: the Polar Regions The polar regions face threats from climate change, ozone depletion, altered land use and the unsustainable use of natural resources. The ocean areas include some of the largest marine ecosystems on Earth and are threatened by commercial fisheries and the harvesting of marine mammals. Arctic The Arctic has considerable biological diversity (see table below). There are also robust populations of plankton in the marine environment. The Arctic fisheries are an important resource: the Bering Sea fisheries alone provide half the US catch and 2–5 per cent of the global catch (CAFF 2001). For centuries the Arctic has attracted hunters of mammals such as whales, seals, walruses, polar bears and otters. Many species have been repeatedly driven to near extinction and some are below safe biological limits. Hunting continues but is now more tightly regulated. Even so, marine mammal populations in decline include local populations of the Beluga whale, walrus, Steller’s sea lion, harbour seal, northern fur seal and the fin whale. For many more marine mammals, the trend is unknown. Several bird populations and fish species are in decline. The latter include local populations of Atlantic cod, Arctic cod, Greenland halibut and wolf-fishes. Many

Polar bear populations in the Arctic

Polar bear populations are stable in the pale blue areas, increasing in the dark blue area. Trends are unknown in grey areas. Largest images of the polar bear denote populations of 3 500, smallest images populations of 500

Source: CAFF 2001

wildlife populations have suffered starvation due to human activity such as overfishing. For example, in the mid-1980s the capelin stock of the Barents Sea collapsed due to overfishing, resulting in the starvation of hundreds of thousands of harp seals. At least 50 000 more were drowned in fishing gear. Norway banned capelin fishing during 1987–90, allowing the capelin population to recover and fishing to resume but at more sustainable levels (NCM 1993). Puffins have been another casualty. They feed their young mainly on herring fry. In the late 1970s, some 1.4 million pairs of puffins nested at the southwestern end of the Lofoten Islands. In the 1980s, the colony contracted at a rate of 10–15 per cent a year. By 1995, it was less than half its former size because most puffin chicks starved to death due to the overfishing of herring fry since the 1960s. By the mid-1990s, puffins had still not recovered despite an increase in the herring population due to strict fishing regulations (Bernes 1996). Reducing exploitation and other responses have had positive impacts on other populations. For example, an Icelandic fishing ban on Atlantic herring between 1972-75 helped the stock to make a gradual recovery and it is now considered to be within safe biological limits. In the 1940s, the Svalbard population of the barnacle goose had been reduced to only 300 birds. It was then totally protected on its winter ranges in the United Kingdom and a nature reserve

Biological diversity in the Arctic: number of known species

Global

Arctic

Arctic %

fungi

65 000 16 000 10 000

5 000 2 000 1 100

7.6

lichens mosses

12.5 11.0

liverworts

6 000

180

3.0 0.5 1.2 1.2 1.2 0.3 1.6 1.8

ferns

12 000

60

conifers

550

8

flowering plants

270 000 75 000 950 000 52 000 25 000

3 000 1 000 3 000

spiders insects

vertebrates

860 450

fishes

reptiles

7 400 4 630 9 950

4

>0.1

mammals

130 280

2.8 2.8

birds

Source: CAFF 2001