Global Environment Outlook 3 (GEO 3)

1 8 3

COASTAL AND MARINE AREAS

entanglement in or ingestion of non-biodegradable litter. Human-induced changes in the natural flow of sediment have emerged since the Stockholm Conference as a major threat to coastal habitats. Urban and industrial development drives the construction of residential and industrial infrastructure which, depending on its nature, can alter sediment flow. In addition, agriculture, deforestation and construction typically mobilize sediments. Deltas, mangrove forests, beaches and other coastal habitats are sustained by the supply of sediment, while other habitats, such as coral reefs and seagrass beds, may be smothered or deprived of light. Sedimentation is one of the major global threats to reefs, particularly in the Caribbean, Indian Ocean, and South and Southeast Asia (Bryant and others 1998, Wilkinson 2000). Fisheries The Stockholm Conference projected that annual harvests could approximately double from 1970 levels to ‘rather more than 100 million tonnes’ (UN 1972b), although the depletion of some fisheries by overexploitation was also recognized. In the same year the world’s largest fishery, the Peruvian anchovy, crashed spectacularly, a result of years of unsustainable harvests precipitated by a strong El Niño event. Harvests from marine capture fisheries did rise but failed to reach 100 million tonnes, fluctuating around 80-90 million tonnes from the mid- 1980s (see graph). Contrary to indications that the global fisheries catch is stable, a recent study reveals that catches have actually been declining for more than a decade (Watson and Pauly 2001). The study shows that vast overreporting of catches by some countries combined with the large and wildly fluctuating catch of the Peruvian anchovy, have painted a false picture of the health of the oceans. Aquaculture production, by contrast, has risen sharply but is entirely dominated by Asia and the Pacific (see graph). The Stockholm Conference recommended two basic approaches to fisheries management: improving management information through research, assessment and monitoring, and international cooperation. Despite great improvement in the quality and scope of fisheries information, better fisheries management has generally not been achieved. There has been an almost inexorable global trend towards increasingly intense exploitation and depletion of fisheries stocks (see figure), three-quarters of which

Annual fish, mollusc and crustacean catch (milllion tonnes) by region

100

West Asia North America

Latin America and the Caribbean

Africa

80

Europe Asia and the Pacific

60

40

20

0

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

Annual fish, mollusc and crustacean catch per capita (kg) by region

60

50

40

30

20

10

0

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

Africa

Europe

Latin America and the Caribbean

West Asia

North America

Asia and the Pacific

Annual aquaculture production (million tonnes) by region

45

West Asia North America Latin America and the Caribbean Europe Asia and the Pacific Africa

40

35

30

25

20

15

10

5

0

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

Global fish, mollusc and crustacean catch seems to have stabilized at around 90 million tonnes but per capita values have declined in Europe and North America; note Latin American variations due to fluctuations in the Peruvian anchovy fishery. Aquaculture production has risen steeply for more than a decade, and is dominated by Asia and the Pacific

Source: compiled from Fishstat 2001 and United Nations Population Division 2001