Acid rain hurting marine organisms

WOODS HOLE, Mass., Sept. 7 (UPI) -- U.S. researchers say acid rain's impact on the world's oceans is greatest along the coastlines.

The report, published online in the Proceedings of the National Academy of Sciences, said ocean acidification hampers the ability of marine organisms to harness calcium carbonate for making hard outer shells or exoskeletons, which provide essential food and habitat to other organisms.

Ocean acidification occurs when chemical compounds such as carbon dioxide, sulfur or nitrogen mix with seawater, a process which lowers the pH and reduces the storage of carbon.

"Acid rain isn't just a problem of the land -- it's also affecting the ocean," lead author Scott Doney of the Woods Hole Oceanographic Institution said Friday in a release. "That effect is most pronounced near the coasts, which are already some of the most heavily affected and vulnerable parts of the ocean due to pollution, over-fishing and climate change."

In addition to acidification, excess nitrogen promotes increased growth of phytoplankton and other marine plants which can cause harmful algal blooms.

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