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.
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.
The shell of the pteropod sea snail in the Southern Ocean was severely dissolved by more acidic surface water, the researchers from the British Antarctic Survey, Royal Netherlands Institute for Sea Research, the US National Oceanic and Atmospheric Administration (NOAA) and other institutions found.
And although the snails did not necessarily die, it increased their vulnerability to predators and infection which could affect other parts of the food chain.
The sea snails are an important source of food for fish and birds as well as an indicator of marine ecosystem health.
Since the start of the industrial revolution, the acidity of surface ocean waters has increased by 30 percent, according to NOAA research.
If CO2 levels continue to rise in the future, surface waters could be almost 150 percent more acidic by the end of this century, levels which have not been experienced for more than 20 million years.