Coasts and Coral Reefs

Home for Two-Thirds of World Population

The sea can have such a powerful influence on coastal communities that local people may know more about the immediate seabed offshore than the land that ranges behind them. " Whereas I can name a hundred or more subsea features around Fogo Island", says Newfoundlander Leslie Harris, "I cannot name more than ten hills or prominent features of the interior".

About 60 percent of the world population lives within 60 kilometres of the coast. According to the United Nations Environment Programme (UNEP), this proportion will rise to 75 percent within two decades. The continental shelf is where over 80 percent of all ocean resources are concentrated. Of the world's 23 mega-cities (those with over 2.5 million inhabitants), 16 are in the coastal belt and are growing at a rate of about one million people per day. These cities almost always grew up because of a sheltered harbour for ships seeking trade, searching for resources, or providing a "relief valve for overpopulation." Coastal cities often provide access to and from the interior through a major river system, and to plentiful sources of animal protein in the seas. Nowadays, the coasts are a powerful magnet for tourism, the world's top growth industry. (Text courtesy of UNESCO)

Sea Level Rise

If global temperature continues to increase, scientists predict a parallel rise in sea level. This is partly due to an increased rate of melting of polar ice-caps, partly to the fact that water expands as it warms - and so sea level goes up. The critical question is by how much?

Ever since the end of the last ice age, the sea has been rising, some 1-2 mm per year in the last century or so. Some times it has been much faster as thick ice has slid off land into the sea. Even at the the current rate, there is constant pressure on coral reefs to keep pace and nesting beaches continue to get narrower, wherever they are not taken away completely by human activities. (Text courtesy of UNESCO)

Related Resources