Figure 1. General information on the study sites and the studied organism.

(a) Map of the study area with sampling sites 1 (control), 2 (intermediate pCO₂) and 3 (high pCO₂). Boxes show mean values (±SD) of each site for: pH, pCO₂, temperature, light and alkalinity. δ¹³C_DIC and δ¹⁸O_seawater (‰) are presented for the primary vent site. The map was created in Adobe Illustrator CS3 (Adobe Systems Inc., San Jose, USA). (b) Image showing A. viridis at sampling site 3 (high pCO₂). Photo credit: M. F. (b).