AB 2:67-74 (2008)  -  DOI: https://doi.org/10.3354/ab00037

ABSTRACT: The effects of medium term (32 d) hypercapnia on the immune response of Mytilus edulis were investigated in mussels exposed to acidified (using CO₂) sea water (pH 7.7, 7.5 or 6.7; control: pH 7.8). Levels of phagocytosis increased significantly during the exposure period, suggesting an immune response induced by the experimental set-up. However, this induced stress response was suppressed when mussels were exposed to acidified sea water. Acidified sea water did not have any significant effects on other immuno-surveillance parameters measured (superoxide anion production, total and differential cell counts). These results suggest that ocean acidification may impact the physiological condition and functionality of the haemocytes and could have a significant effect on cellular signalling pathways, particularly those pathways that rely on specific concentrations of calcium, and so may be disrupted by calcium carbonate shell dissolution.

KEY WORDS: Mytilus edulis · Ocean acidification · Carbon capture and storage · Seawater pH · Immune response · Phagocytosis