Shells of live molluscs from the Southern Ocean are showing signs of severe dissolution, reports a study published online this week in Nature Geoscience. The findings suggest that the effects of ocean acidification on marine ecosystems are beginning to emerge.

Geraint Tarling and colleagues examined shells collected from live molluscs in the surface waters of the Southern Ocean, which circles Antarctica. Shells sampled from more acidic regions of the ocean showed significant signs of dissolution. The researchers attribute the dissolution to the mixing of deep carbon-dioxide-rich waters with surface waters affected by atmospheric carbon dioxide.

In an accompanying News and Views article, Justin Ries suggests that the corrosion documented "may be a harbinger of what is in store for surface waters throughout much of the Southern Ocean".