Phenotypic plasticity of coralline algae in a High CO2 world

It is important to understand how marine calcifying organisms may acclimatize to ocean acidification to assess their survival over the coming century. We cultured the cold water coralline algae, Lithothamnion glaciale, under elevated pCO(2) (408, 566, 770, and 1024atm) for 10months. The results show that the cell (inter and intra) wall thickness is maintained, but there is a reduction in growth rate (linear extension) at all elevated pCO(2). Furthermore a decrease in Mg content at the two highest CO2 treatments was observed. Comparison between our data and that at 3months from the same long-term experiment shows that the acclimation differs over time since at 3months, the samples cultured under high pCO(2) showed a reduction in the cell (inter and intra) wall thickness but a maintained growth rate. This suggests a reallocation of the energy budget between 3 and 10months and highlights the high degree plasticity that is present. This might provide a selective advantage in future high CO2 world.