Unexpected result: Ocean acidification can also promote shell formation More carbon dioxide in the air also acidifies the oceans. It seemed to be the logical conclusion that shellfish and corals will suffer, because chalk formation becomes more difficult in more acidic seawater. But now a group of scientists discovered to their own surprise that some tiny unicellular shellfish (foraminifera) make better shells in an acidic environment. This is a completely new insight. https://www.sciencedaily.com/releases/2017/01/170127112942.htm