Sources and impacts of Ocean pollutions

1. 80% of marine pollution comes from land-based sources.

2. In many developing countries 90% of waste water and 70% of industrial waste are discharged without treatment.

3. 6.5 million tons of litter enter the world’s ocean each year. 50% is long-lasting plastic that will drift for hundreds of years before it is degraded.

4. There are 200  known as ‘dead zones’, or areas deprived of oxygen and devoid of life (area between 1 and 70 000 km2) in the world Ocean: this number has doubled every decade since 1960.

5. 12 billion tons of ballast waters containing, at any one time, 3,000 marine species are shipped around the world spreading alien and invasive species.

6. Human health suffers from contamination of coastal water: 250 million of clinical cases (gastroenteritis + respiratory diseases) are caused annually by bathing in contaminated waters.

7. Eating infected shellfish causes 50 000 to 100 000 deaths every year.

8. The global economic cost related to pollution of coastal waters is $16 billion annually, much of which is due to human b>health impacts.

9. Documented economic losses caused by accidental or deliberate introductions of non-indigenous species in the Ocean amount to hundreds of millions of US dollars.


N°1; 2; 5; 6: World Summit on Sustainable Development 2002 – ” A Guide to Oceans, Coasts and Islands”
N°3: Marine litter – an analytical overview – UNEP 2005
N°4: MSNBC News Services
N°7: Pollution from the land 2001– Global Plan of Action brochure
N°8: UNEP – Marine and coastal Ecosystems and Human Well-Being – Report Millennium Ecosystem Assessment
N°9: GESAMP (Group of Experts on Scientific Aspects of Marine Environmental Protection) Report 71 – Protecting the Oceans from Land-based Activities-2001

Problems linked to living resources exploitation

1. 75% of fisheries worldwide are fully exploited or overexploited.

2. 100 million sharks are killed each year for their meat and fins, which are used for shark fin soup.

3. Marine ecologist Ransom Myers (Canada) announced large predatory fish biomass (tuna, cod, swordfish and marlin…) is only 10% of pre-industrialized levels. In November 2006, he predicted that world’s fish and seafood populations could collapse by 2048 if current trends in habitat destruction and over-fishing continue.

4. Outside China, per capita food fish supply in 2004 was estimated at 13.5 kg against 14.6 kg in 1987 because the world’s population has been increasing more quickly than the total food fish supply.

5. 70% of marine mammals are threatened.

6. The 2003 IUCN Red List has highlighted new threats to marine species with many new additions to the List, and numerous other species seen moving to higher degrees of vulnerability.


N° 1; 4: FAO/SOFIA 2006
N°2: UNEP World Environment Day 2004
N°3: Letters to Nature/« Rapid worldwide depletion of predatory fish communities » Ransom A. Myers & Boris Worm
N°5: World Summit on Sustainable Development 2002 – A Guide to Oceans, Coasts and Islands

Loss or degradation of coastal habitat

1. 1/3 of coastal regions run a high risk of degradation, especially from infrastructure development and pollution. In 4/7 of coastal regions, the degradation is increasing.

2. 60% of the Pacific and 35% of the Atlantic Coast shoreline are eroding at a rate of a meter every year.

3. About 30 per cent of the world’s reefs are seriously damaged and 60 % of reefs could be lost by 2030.

4. An estimated 35 per cent of mangrove forest has disappeared, and some countries have lost 80 per cent of cover.

5. The price to pay for maintaining marine coastal ecosystems is much lower than the benefit received. For example, the estimated average operational management cost of a marine protected area is US$775 per km2, or less than 0.2 per cent of the estimated global value of a square kilometre of reef or mangrove.


N°1: UN Ocean Atlas
N°3: « Marine and Coastal Ecosystems and Human Well-being” Synthesis report based on the findings of the Millennium Ecosystem Assessment/UNEP
N°4; 5:“In the Front Line – Shoreline protection and other ecosystem services from mangroves and coral reefs” – UNEP/ICRAN/IUCN

Climate change – observations and projected impact

1. The total temperature increase from 1850 – 1899 to 2001 – 2005 is 0.76°C. Projections for the end of the 21st century relative to 1980–1999 estimates give ranges for globally average surface air warming from 1.8°C to 4.0°C.

2. The total 20th century rise observed sea level rise is estimated to be 0.17 m. Projections of global average sea level rise at the end of the 21st century are between o,18 m to 0,59 m (in 2090-2099 relative to 1980-1999).

3. Sea ice is projected to shrink in both the Arctic and Antarctic. In some projections, Arctic late-summer sea ice disappears almost entirely by the latter part of the 21st century.

4. Increasing atmospheric carbon dioxide concentration leads to increasing acidification of the Ocean. Corals and other marine organism use carbonate (CO3) mineral to construct their skeleton. When CO2 increases in the Ocean, carbonates concentration lowers. The increasing of atmospheric CO2 could result in a significant decrease in the reef-building process.

5. Approximately 20-30% of plant and animal species assessed so far are likely to be at increased risk of extinction if the increase in global average temperature exceeds 1.5-2.5°C.

6. There is observational evidence of an increase of intense tropical cyclone activity in the North Atlantic since about 1970, correlated with increases of tropical sea surface temperatures. There is no clear trend in the annual numbers of tropical cyclones.

7. 46 million people per year are currently at risk of flooding from storm surges.

8. A 1 meter of sea water rise may eliminate entire small island nations and many deltaic areas will be lost.

9. By 2100, in South Asia and Sub Saharan Africa, up to 145 – 220 million additional people could fall below the $2-a-day poverty line, and every year an additional 165,000 – 250,000 children could die compared with a world without climate change.

10. The Stern Review on the Economics of Climate change issued in 2006 estimates that if we don’t act, the overall costs and risks of climate change will be equivalent to losing at least 5% of global GDP each year. If a wider range of risks and impacts is taken into account, the estimates of damage could rise to 20% of GDP or more. In contrast, the costs of action – reducing greenhouse gas emissions to avoid the worst impacts of climate change – can be limited to around 1% of global GDP each year.


N° 1; 2; 3; 4; 6: IPCC Climate Change 2007: The Physical Science Basis – Summary for Policymakers
N° 5: IPCC, Climate Change 2007: Impacts, Adaptation and Vulnerability– Summary for Policymakers
N° 7; 8: World Summit on Sustainable Development 2002 – A Guide to Oceans, Coasts and Islands
N° 9; 10: United Kingdom’s economics and finance ministry (HM Treasury) – Stern Review on the Economics of Climate change

Law of the sea – actual limits

1.  An estimated 64% of the Ocean lie beyond the 200-nautical-mile limit of the Exclusive Economic Zones (EEZs) of coastal states. These areas, known as the High Seas, comprise 80% of the planet’s biosphere and include vast open Ocean and deep sea environments that are some of the least explored and researched areas on Earth.

2. While the Oceans comprise over 70% of the Earth’s surface, less than 1% of the marine environment is within protected areas, compared with nearly 9% of the land surface.

3. One industry source estimates 1300 fishing vessels of significant size are flying flags of convenience (ships which are likely to be involved in contravening international and local fishing policies, guidelines and protected areas).

4. It is estimated that on average 300 000 seabirds are killed annually owing to illegal discharges of bilge oil from ships in the Grand Banks region (Canada).


N°1; 3: WWF
N° 2: World Summit on Sustainable Development 2002 – A Guide to Oceans, Coasts and Islands
N°4: Global Conference on Ocean Coasts and Islands 2003