New study shows extent of harmful human influences on global ...( More than 40 percent of the worlds ...),Health

More than 40 percent of the worlds oceans are heavily impacted by human activities, including overfishing and pollution, according to a new study that will appear in tomorrows peer-reviewed journal Science.

Dr. Kenneth Casey, with NOAAs National Oceanographic Data Center in Silver Spring, Md., and co-author of the study A Global Map of Human Impact on Marine Ecosystems, joined a team of researchers that combined 17 data sets of different human activities from fishing and fertilizer run-off, to commercial shipping and pollution and analyzed their effects on marine ecosystems, continental shelves and the deep ocean.

The results, highlighted on a map available on NOAA.gov, revealed the most heavily affected waters include the East Coast of North America, North Sea, South and East China Seas, Caribbean Sea, Mediterranean Sea, Red Sea, Persian Gulf, Bering Sea and areas off the western Pacific Ocean. Least affected areas are near the poles.

Casey said three measures of human-induced climate change were examined by the research team, including changes in sea surface temperatures, UV radiation, and ocean acidification. These measures were found to be among the most important factors in determining the global impacts.

The extent of human influence was probably more than any of us expected, said Casey, explaining that red areas on the map indicate the most heavily impacted regions. He added the study and map designed to visually highlight the trouble spots in the oceans are tools for the worlds decision-makers to assess the real impact of human activities on marine ecosystems and help identify ways to lessen the threats.

According to the study, the ecosystems most at threat are: coral reefs, which house more than 25 percent of all marine life and protect against wave erosion; seagrass beds, which are nursery grounds for young fish and mangroves, which grow in coastal habitats and also help ward off erosion.