The state of the world’s oceans continues to deteriorate. As new threats to the health and viability of the oceans emerge, most of the problems identified decades ago have still not been solved and many have become worse, according to a study carried out in 2001 by the United Nations Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection. At risk are the vast resources of the oceans and the many economic benefits that humanity derives from them, estimated to be about $7 trillion per year.

Coastal areas  the most productive marine environments are the most affected. Currently more than half of the world’s population lives within 100 kilometers of the coast, with two thirds of all cities with over 2.5 million inhabitants. By 2025, it is expected that 75 per cent of the world’s population will live in coastal areas.

The large-scale movements of populations to coastal areas have been coupled with a significant increase in economic activity and industrialization along the coastline such as oil and gas exploration, mining, fish farming, tourism, development of ports, marinas and coastal defenses  putting enormous pressure on coastal areas. Pollution, the overexploitation of marine resources and the destruction of marine environments are the greatest threats to the oceans. About 80 per cent of all pollution entering the oceans comes from land-based sources: this includes both land-based discharges and discharges through the atmosphere. The rest is due to maritime transportation, dumping and offshore production.

Marine experts of United Nations organizations listed 20 issues of global concern regarding deterioration of the marine environment:

• Harmful algal blooms

• The effects of classical contaminants (sewage, metals, persistent organic substances, petroleum hydrocarbons, radio nuclides)

• The effects of deforestation

• The effects of increased or decreased mobilization of sediments

• The demise of coral reefs

• The loss of wetlands

• Declines in mangroves

• Habitat destruction

• The transfer of harmful species into coastal areas

• Climate change

• Sea-level rise

• Inundation as a consequence of physical alteration

• Increased risks to human health

• Reduced biodiversity

• Endocrine-disrupting chemicals

• Over fishing

• Destructive fishing practices

• The effects of the exploitation of coastal mineral resources, particularly sand and gravel and

• Litter