Large areas of the east coast of North America and the Caribbean Sea are among the oceans in the world most heavily affected by human activities. Thatâ€™s the upshot of a global study from the University of California at Santa Barbara this week. According to its findings, more than 40 percent of the worldâ€™s oceans are heavily affected by human activities, such as fishing, climate change and pollution, and few if any areas remain untouched. By overlaying 17 different maps of human activities, researchers came up with a composite map of the toll exacted by humans on the seas. Other ocean areas most severely affected include the North Sea, the South and East China Seas, the Mediterranean Sea, the Red Sea, the Persian Gulf, the Bering Sea, and several regions in the western Pacific. The least affected areas are largely near the poles.