Bad news for bivalves comes this week from scientists studying ocean acidification.
Ocean water in parts of the world is changing. Its chemistry is very slowly becoming more acidic, like lemon juice, and less alkaline, a la baking soda.
The change so far is small — you wouldn't notice if you swam in the ocean or even drank it (not recommended, in any case). But numerous scientific studies show that it could get worse. One reason is that as humans produce more carbon dioxide, a lot is absorbed into the oceans. That makes the water more acidic.