Urbanization

Approximately 66% of the human population, or close to four billion people, now live within 80 kilometres of the coast. This figure isexpected to increase to 75% by 2020. Such a dense coastal population and the attraction of the coast as a travel destination exert increasing direct and indirect pressures on marine and coastal ecosystems through extensive coastal development.

Direct physical alteration and destruction of native habitats occur in coastal regions through dredging for shipping channels and harbours, the filling of shallow habitats for coastal building, and contamination of water sources.

Indirectly, poorly planned urban, industrial and port developments contribute to the destructive effects of land-based sources of pollution to the marine environment through contaminated sediment. Watersheds cleared of their forests and other vegetation covers are vulnerable to erosion and flooding. During high water periods, silt and pollutants within these basins are carried far beyond normal, impacting a greater number and extent of coastal habitats.