A set of experiments undertaken in Hawaii, Moorea and Okinawa, and now documented in the journal Proceedings of the Royal Society B, offer a glimmer of hope for the future of coral reefs under the continuing threat of Ocean Acidification. In the study, two coral taxa (Pocillopora damicornis and Porites) and two calcified algae (Porolithon onkodes and Halimeda macroloba) were subjected to conditions that mimic oceans if CO2 concentrations in the atmosphere reached 1000 ppm, more than double the levels today. Surprisingly, three out of the four could still easily form their hard calcium shells even in such an acid ocean. Although positive, the discovery doesn’t necessarily mean that ocean acidification won’t be bad for corals and algae though. It does mean that across the Pacific some of species may prove to be more resilient than others.