By Alok Jha in Boston
The Guardian
Friday February 15 2008

A global map of the overall impact that 17 different human activities are having on marine ecosystems. Insets show three of the most heavily impacted areas in the world, and one of the least impacted areas.

Fishing, climate change and pollution have left an indelible mark on virtually all of the world's oceans, according to a huge study that has mapped the total human impact on the seas for the first time. Scientists found that almost no areas have been left pristine and more than 40% of the world's oceans have been heavily affected.

"This project allows us to finally start to see the big picture of how humans are affecting the oceans," said Ben Halpern, assistant research scientist at the University of California, Santa Barbara, who led the research.

"Our results show that when these and other individual impacts are summed up the big picture looks much worse than I imagine most people expected. It was certainly a surprise to me."

Human impact is most severe in the North Sea, the South and East China Seas, the Caribbean, the Mediterranean, the Red Sea, the Gulf, the Bering Sea, along the eastern coast of North America and in much of the western Pacific.

The oceans at the poles are less affected but melting ice sheets will leave them vulnerable, researchers said.

The study found that almost half of the world's coral reefs have been heavily damaged. Other concerns rest with seagrass beds, mangrove forests, seamounts, rocky reefs and continental shelves. Soft-bottom ecosystems and open ocean fared best but even these were not pristine in most locations.

For the full article, please visit: http://www.guardian.co.uk/science/2008/feb/15/biodiversity.scienceofclimatechange \\