Short-term physiological response of the Pacific oyster, Crassostrea gigas, on exposure to varying levels of polycyclic aromatic hydrocarbon

In the present study, we investigate the short‐term adaptive physiological strategies to polycyclic aromatic hydrocarbon (PAH) of Pacific oysters, Crassostrea gigas, by exposing the oysters to varying levels of PAH (0, 50, 100 and 200 μg L^?1) for 7 days with a 3‐day acclimation period under laboratory conditions. The filtration rate (FR) and respiration rate (R) increased significantly at 50 μg L^?1 PAH and decreased at 100 and 200 μg L^?1 compared with the control. The absorption efficiency (Abs. eff.) was significantly impaired at 200 μg L^?1 PAH. Ammonia excretion (E) increased with increasing PAH levels, with a significant elevation at 200 μg L^?1. Although a significantly elevated FR was observed, oysters exposed to 50 μg L^?1 PAH showed scope for growth (SFG) similar to the control. This indicates that even at nominal levels, PAH contamination is a possible cause of reduced oyster production because of increased food demand. The oysters exposed to 200 μg L^?1 PAH showed negative SFG values, which could be a possible cause of growth stagnation or even mortality when the exposure is chronic.