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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


The Continental Shelf

The area fringing coastal landmasses is known as the continental shelf; during ice ages, when sea levels were lower, the shelf was the boundary of the continents but now extends offshore underwater by an average of 80 km. Continental shelf waters are relatively shallow, generally between 100 and 200 metres deep; because their shallowness means they are bathed in sunlight in their upper layers and because their relative proximity to shore provides them with ongoing sources of nutrients from land, they are some of the most productive waters in the ocean. Coral reefs, seagrasses and kelp forests are all in continental shelf waters, as are the vast majority of the world’s fisheries.

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  • United Nations
  • United Nations Environment Programme