LONDON (Reuters) - The shells of some marine snails in the seas around Antarctica are dissolving as the water becomes more acidic, threatening the food chain, a study published in the journal Nature Geoscience said on Sunday. Oceans soak up about a quarter of the carbon dioxide released into the atmosphere each year and as CO2 levels in the atmosphere increase from burning fossil fuels, so do ocean levels, making seas more acidic. Ocean acidification is one of the effects of climate change and threatens coral reefs, marine ecosystems and wildlife. http://news.yahoo.com/sea-snails-show-impact-more-acidic-ocean-043126388.html