The ever more popular coasts

Humanity is increasingly gravitating towards the coasts. About one in every three people on the planet now live within 100 kilometres of the sea, and 44 percent of the world’s population – more people than inhabited the entire globe in 1950 – are within 150 kilometres of it. Two thirds of all the cities with over 2.5 million inhabitants are on the coast, and they are growing fast. Casablanca’s population soared from 600 in 1839 to 29,000 in 1900, and to almost 5 million today. Dar Es Salaam is growing by 7.8 percent a year, well over twice as fast as population growth in Tanzania as a whole. The rate of population growth in coastal areas is accelerating and increasing tourism adds to the pressure on the environment.

The more people that crowd into coastal areas, the more pressure they impose both on land and sea. Natural land-scapes and habitats are altered, overwhelmed and destroyed to accommodate them. Lagoons and coastal waters are ‘reclaimed’, wetlands are drained and covered with rubbish, the floodplains around estuaries are built over and reduced, and mangroves and other forests are cut down. Ecosystems are damaged, frequently lost forever. Fish stocks, fresh water, soils and beach sands are often overexploited, at great economic and ecological cost.

Increasing volumes of waste, particularly sewage, are sluiced out into coastal waters: this can cause eutrophication and endanger public health. Garbage is of-ten dumped on important habitats, like wetlands. and mangroves; they are destroyed, and contaminants leach from the rubbish into coastal waters. The waste itself is increasingly getting into the sea, either by accident or design.