The acidification experiment on the sea urchins is now running rather smoothly. An aquarium system has been set up and the Aquatronica material is doing a very good job for controlling the pH. The first results indicate that Sterechinus neumayeri is reacting very quickly to acidification: the acid-base balance of the inner fluid is already controlled after 4 days of progressive decrease of the sea water pH. This supports the hypothesis emitted in our previous work on Antarctic sea urchins and published in Global Change Biology (Collard et al. 2014, GCB doi: 10.1111/gcb.12735 )