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IDB2012 booklet

IDB 2012

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The Green Wave

International Day for Biological Diversity 2012


Marine Biodiversity was the theme for International Day for Biological Diversity (IDB) in 2012. Designation of IDB 2012 on the theme of marine ecosystems provides Parties to the Convention on Biological Diversity (CBD) and everyone interested in marine life, the opportunity to raise awareness of the issue and increase practical action.


How Much Life Is in the Sea?

From 2000 to 2010, an unprecedented worldwide collaboration by scientists around the world set out to try and determine how much life is in the sea.

Dubbed the ‘Census of Marine Life’, the effort involved 2,700 scientists from over 80 nations, who participated in 540 expeditions around the world. They studied surface seawater and probed the deepest, darkest depths of the ocean, sailed tropical seas and explored ice-strewn oceans in the Arctic and Antarctic.

By the time the Census ended, it had added 1,200 species to the known roster of life in the sea; scientists are still working their way through another 5,000 specimens to determine whether they are also newly-discovered species. The estimate of the number of known marine species - the species that have been identified and the ones that have been documented but await classification - has increased as a direct result of the Census efforts, and is now around 250,000. (This total does not include some microbial life forms such as marine viruses.) In its final report, the Census team suggested it could be at least a million. Some think the figure could be twice as high.


Marine and Coastal Biodiversity

Along the Coast

The Continental Shelf

The Open Ocean

The Deep

Great Migrations

The Human Impact

Causes of Decline

A Warmer Ocean

A More Acidic Ocean

The Problem of Over-Fishing

Why We Should Care

Blue Carbon

The Value of Marine Reserves

CBD and the Jakarta Mandate


Causes of Decline

Many different human activities impact marine and coastal wildlife and ecosystems. Over-hunting has reduced the numbers of many marine species. Toxic pollution from chemical compounds and heavy metals can affect the reproduction, growth, and behavior of seabirds, fish and other marine wildlife. Nutrient pollution, the result of excess nitrogen from, for example, fertilizers and animal waste entering coastal waters, can cause a phenomenon known as eutrophication, which ultimately results in areas of seawater where oxygen levels are greatly reduced. Dam construction can alter the flow of rivers, and the transport of needed sediments and nutrients, to coastal ecosystems. Coastal urbanization can ‘squeeze’ ecosystems like sandy beaches. Plastic debris can entangle, strangle and be eaten by marine life. Non-native species, released from aquariums or discharged in ships’ ballast water, can invade ecosystems and out-compete native species. Even the noise generated by shipping and industrial activity can prevent species like whales from communicating with each other across miles of ocean.

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  • United Nations
  • United Nations Environment Programme