Variable effects of a Sub Lethal ‘Heat Wave’ on juvenile Olympia Oysters (Ostrea lurida) previously exposed to Low pH conditions

Abstract

With more anthropogenic CO2 equilibrating with the oceans and decreasing the concentration of carbonate ions, ocean acidification is a current concern for all marine organisms, especially those that build calcium carbonate shells like the Olympia Oyster. This study looks at the effect of elevated pCO2 levels with a subsequent heat shock on the mortality rates of juvenile Olympia Oysters. The oysters were bred from adults at Totten Inlet. The juveniles were exposed to pH levels of 7.27, 7.64 and 8.02 and then put through a sub lethal and lethal heat shock. Unexpectedly, the oysters from the lowest pH level seemed to have higher survival rates than the oysters from the highest pH level. This could be attributed to the release of the chaperone protein that can help the organism with a secondary stress.