Coastal and Marine Ecosystems
Length of Coastline was derived from the World Vector Shoreline database of the United States Mapping Agency. The estimates presented here were calculated using a Geographic Information System (GIS) with a resolution of 1:250,000 kilometers and an underlying database consistent for the entire world. In general, the coastline length of islands that are part of a country, but are not overseas territories, are included in the coastline estimate for that country (i.e., Canary Islands are included in Spain)
Percent of Population within 100 km of Coast. Estimates were based on 1995 population figures. The Gridded Population of the World is a raster data set that provides information on the spatial distribution of the world's human population. The grid cells are approximately 4.6 km on each side. Populations are distributed according to administrative districts which vary in scale, level and size from country to country. A 100 km coastal buffer with a 10 km 'safe area' falling into the sea were used in the geographic information system to calculate the number of people in the coastal zone for each country individually.
Area of Continental Shelf. According to the UN Convention of the Law of the Sea, the Continental Shelf is the area of the seabed and subsoil which extends beyond the territorial sea to a distance of 200 nautical miles from the territorial sea baseline and beyond that distance to the outer edge of the continental margin. Coastal States have sovereign rights over the continental shelf (the national area of the seabed) for exploring and exploiting it; the shelf can extend at least 200 nautical miles from the shore, and more under specified circumstances.
Territorial Sea is defined under the United Nations Convention on the Law of the Sea (UNCLOS) as the 12-nautical mile zone from the baseline or low-water line along the coast. The coastal State's sovereignty extends to the territorial sea, including its sea-bed, subsoil, and air space above it. Foreign vessels are allowed "innocent passage" through those waters. Even though the established limit for a territorial sea is 12 nautical miles, some countries claim larger areas.