Mankind, the sea's worst nightmare

Only 3.7 percent of the ocean is not heavily impacted by human activity, and the most of untouched areas are in the poles, where seasonal or permanent ice limits human reach.

A study by the US National Center for Ecological Analysis and Synthesis (NCEAS) found that more than 40 percent of oceans are deeply affected by overfishing, pollution and biochemical changes due to global warming.

Scientists from a broad range of universities, NGOs and government agencies, produced a global map on how human activities are eroding sea ecosystems.

Things could be soon changing even in the less affected areas.

“As polar ice sheets disappear with global warming and human activities spread into these areas, there is a risk of rapid degradation of these relatively pristine ecosystems,” said Dr Carrie Kappel, an expert from NCEAS.

Co-author and researcher from Univerty of Hawaii, Dr Kim Selkoe, said that higher temperatures increase plankton levels, and change species composition and ocean circulation.

Mankind fishes over 80 percent of the oceans, and now many species are under threat of extinction. Simultaneously, heavy shipping traffic spills fuel and produce noise pollution, which disturbes many species.

According to the study, published in Science magazine, the most affected waters include large areas of the North Sea, the South and East China Seas, the Caribbean Sea, the east coast of North America, the Mediterranean Sea, the Red Sea, the Persian Gulf, the Bering Sea, and several regions in the western Pacific.

More facts

According to recent reports by scientists and Inter-Governmental Panel on Climate Change (IPCC):

The West Antarctica lost 132 billion tons of ice in 2006, compared to about 83 billion tons in 1996.

The sea surface warming was responsible for approximately 40 percent of the increase in Atlantic hurricane activity between 1996 and 2005.

The Arctic sea ice shrank last September to a low of 4.1 million sq km (1.6 million sq miles), more than 1.2 million sq km less than the previous recorded low in 2005.