Effects of Warm Water Discharge from Sanmen Nuclear Power Plant on Filtration Behavior, Calcification Rate, and Ammonia Excretion of Razor Clam, <i>Sinonovacula constrict</i><i>a</i>: A Simulation Study

Abstract

Warm water discharge from nuclear power plant will elevate the temperature of seawater and may subsequently have influences on important marine aquiculture bivalves. In present study, the effects of temperature elevation caused by warm water discharge on the filtration behavior, calcification rate, and ammonia excretion of a major local bivalve species, razor clam, were investigated via laboratory simulation. The results showed that the filtration rates of razor clam increased significantly with an increased temperature, which were 0.46±0.06, 0.62±0.09, and 0.85±0.08L/g·h for 28 °C, 30 °C, and 32 °C, respectively. Under the experimental temperature gradient, the pattern of calcification rates of razor clam was shown to be bell-shaped, with the highest calcification rate 2.85±0.28μmol/FWg·h at 30 °C. The ammonia excretion rates were shown to increase slightly with increased temperature, which were 0.31±0.03, 0.32±0.09, and 0.34±0.06mg/ g·h for 28 °C, 30 °C, and 32 °C, respectively. The results suggest that razor clam will increase its energy intake and metabolic rate to maintain a relatively constant growth rate under thermal stress within 4 oC range even during the summer season.