FACTBOX - UN Warns on State of World\'s Oceans

Following are some UNEP facts about the seas:

- Oceans cover 70 percent of the world\'s surface and more than 90 percent of the world\'s living biomass - from seaweed to blue whales - is found in the oceans.

- More than 3.5 billion people, more than half the world\'s six billion population, depend on the seas for their primary source of food. The numbers could double to 7.0 billion in 20 years.

- More than 70 percent of the world\'s marine fisheries are fished up to or beyond their sustainable limit. Stocks of fish such as tuna, cod, swordfish and marlin have declined by up to 90 percent in the past century.

- Governments at a 2002 Earth Summit in Johannesburg agreed \"on an urgent basis and where possible by 2015, to maintain or restore depleted fish stocks.\"

- The summit also called for elimination of government subsidies. Estimated at $15-$20 billion a year, subsidies account for almost 20 percent of revenues to the fishing industry worldwide and can promote excess fishing.

- Eighty percent of all pollution in the seas comes from land-based activities. By 2010, 80 percent of the world\'s population will live within 100 km (62.14 miles) of coastlines.

- Death and diseases caused by polluted coastal waters cost the global economy $12.8 billion every year.

- Plastic waste, like supermarket bags, kills up to one million seabirds, 100,000 sea mammals and countless fish yearly.

- An estimated 21 million barrels of oil run into the oceans every year from sources ranging from run-off from streets to ships flushing their tanks.

- In the past decade, an average of 600,000 barrels of oil a year have been accidentally spilled from ships - the equivalent of 12 disasters the size of the sinking of the Prestige tanker off Spain in 2002.

- Sea levels have risen by 10-25 cm in the past 100 years and global warming is threatening further rises. Higher sea levels could destroy corals and swamp some low-lying nations in the Pacific.

- Tropical coral reefs are found off 109 nations - significant damage has occurred to reefs off 93 of them, from factors including coastal development and tourism.

- Coral reefs comprise less than 0.5 percent of the ocean floor but more than 90 percent of marine species are directly or indirectly linked to them. The 2,000 km (1,200 mile) long Great Barrier Reef off Australia is the largest living structure on the planet, visible from the Moon.