Municipal, industrial and agricultural wastes and run-off account for as much as 80 per cent of all marine pollution.

Sewage and waste water, persistent organic pollutants (including pesticides), heavy metals, oils, nutrients and sediments - whether brought by rivers or discharged directly into coastal waters - take a severe toll on human health and well-being as well as on coastal ecosystems. The result is more carcinogens in seafood, more closed beaches, more red tides, and more beached carcasses of seabirds, fish and even marine mammals.

The first regional steps to deal with this widespread problem were taken in the Mediterranean, with the adoption of the Protocol on Land-Based Sources of Pollution in May 1980 after three years of difficult and delicate negotiations. Over the next two decades, this landmark agreement led to similar regional agreements in other Regional Seas.

One billion people in developing countries depend on fish for their primary source of protein, making them vulnerable to the chemicals they carry.

Over the next two decades, Regional Seas programmes around the world have established similar agreements, guided largely by the 1995 Global Programme of Action for the Protection of the Marine Environment from Land-based Activities (GPA), which works to identify the sources of land-based pollution or harmful activities, and prepares priority action programmes of measures to reduce them.