The Woods Hole Oceanographic Institution researchers said their finding raises new questions about carbon dioxide's impact on marine life, since ocean acidification is caused by high levels of atmospheric CO2.
Scientists have been concerned about the ability of certain organisms to maintain shell strength in such water since carbon dioxide is known to trigger a process that reduces the abundance of carbonate ions in seawater. Carbonate ions are one of the primary materials marine organisms use to build shells and skeletons.
But in the study, a team led by former WHOI postdoctoral researcher Justin Ries found seven of the 18 shelled species studied built more shell when exposed to varying levels of increased acidification.
"Most likely the organisms that responded positively were somehow able to manipulate … dissolved inorganic carbon in the fluid from which they precipitated their skeleton in a way that was beneficial to them," said Ries, now an assistant professor at the University of North Carolina. "They were somehow able to manipulate CO2 … to build their skeletons."
Organisms displaying such improvement also included calcifying red and green algae, limpets and temperate urchins. Mussels showed no effect.
The study is detailed in the journal Geology.