Over half of the world’s human population live in coastal areas (less than 50km from the sea). Many people depend on the sea for their livelihood: fishery, port activities, tourism, etc. Eighty percent of all human activities take place in coastal zones, inevitably causing some harm to the marine environment, through oil spills, sewage disposal, sand mining, and so on. Overfishing fosters coastal erosion, which causes economic losses, e.g. by sedimentation, which in turn necessitates expensive dredging operations.
Today, conservation of the sea and coastline is receiving increasing attention. For example, a joint programme of IUCN (International Union for Conservation of Nature) and UNEP (United Nations Environmental Programme), under the aegis of the Barcelona Convention, is helping the countries around the Mediterranean to create protected marine areas and adopt a common approach for managing their coastlines. The OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic entered into force in 1998, which moreover was the International Year of the Ocean (IYO).
Both optical and radar satellite data can be of great help
for sustainable management of oceans and coastal environments.
In coastal areas, satellite data are used to locate navigable
channels and perform bathymetric measurements, identify schools
of fish, detect oil spills, but also to monitor coastlines,
water quality, sedimentation, and fragile marine ecosystems
such as reefs and mangroves. Radar images are particularly useful
for detecting oil spills, sand banks, etc.
Further out on the open sea, satellite data are used to map
currents, measure and monitor water surface temperature, and
help determine the most suitable shipping routes. Radar data
can also be used to validate and improve forecasting models
for waves and storms.
