Seawater carbonate chemistry and growth retardation of Pacific oyster Crassostrea gigas

We evaluated the recovery capacity of a model calcifier, the Pacific oyster Crassostrea gigas. We exposed juveniles to 15 pH conditions between 6.4 and 7.8 for 14 days. Oyster growth was retarded below pH 7.1 while shells were corroded at pH 6.5. We then placed the oysters under ambient pH > 7.8 for 42 days. The oysters from each pH condition were briefly dried with absorbent paper and the total wet body weight was measured with a Mettler precision balance (Mettler-Toledo) during the exposure period on days 6, 10 and 14, and then during the ambient pH period on days 4, 7, 9, 11, 14, 18, 22, 28, 36 and 42.