Scientists have shown that lobster shells (and shells of other food-providing animals) get thicker when living in water with higher CO2, so why should we be worried about OA?
At least one experimental study showed that the shell mass of several crustaceans, including lobsters, reared in culture for 60 days actually increased with increased CO2. Shell-making requires energy, so increased shell mass almost certainly occurred hand-in-hand with reduced energy for other functions like growth and reproduction. Also, lobsters and other crustaceans make shells using both calcium carbonate and chitin in a different mechanism than other marine organisms. They shed their shell periodically, rather than growing constantly throughout life, and they are thought to retain many of the minerals from their old skeleton to put into the new skeleton. Energy and mineral budgets were not monitored in the above study, so how OA affects the overall health and longevity of these organisms is still not known.
