A new study published in this week's issue of Science has found that more than 40 percent of the world's oceans are heavily affected by human activities, and virtually all areas have been disturbed more or less by anthropic influences.

The study has looked at global data on human impacts to marine ecosystems such as coral reefs, seagrass beds, continental shelves and the deep ocean. The research was conducted at the National Science Foundation (NSF)'s National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California at Santa Barbara. In addition, other 19 scientists from a range of universities, NGOs, and government agencies have worked on the study.

"This research is a critically needed synthesis of the impact of human activity on ocean ecosystems," said David Garrison, biological oceanography program director at NSF. "The effort is likely to be a model for assessing these effects at local and regional scales."

Anthropic threats include overfishing, pollution, and rising ocean temperatures and ocean acidification caused by global warming. Around 17 types of human impacts on the world's oceans have been taken into account.

The research has produced a map of the world's oceans which shows in a easy to comprehend graphic format the magnitude and location of human influences on them. The most affected region of the world's oceans are topped by the eastern Caribbean, the North Sea, the eastern North American seaboard, the Mediterranean, and the waters around Japan.

"For the first time we can see where some of the most threatened marine ecosystems are and what might be degrading them," said study co-author Elizabeth Selig of the University of North Carolina.

Image credit: NSF