The effect of potential future atmospheric CO2 levels on the Manila clam, Venerupis philippinarum sampled in the west coast of Korea

Abstract

The potential future atmospheric CO2 levels have been presented using a new scenario, Representative Concentration Pathways (RCP) by the 5th Assessment Report of Intergovernmental Panel on Climate Change (IPCC). According to it, atmospheric CO2 level is expected to be from 421ppm (RCP2.6) to 936ppm (RCP8.5) in the year 2100. High atmospheric CO2 dissolves into the surface of ocean, lowers the pH of seawater and thus is expected to pose a potential threat to marine organisms, especially which have shells. We focused on the physiological and behavioral responses of adult Manila clams, Venerupis philippinarum (n = 96, shell length 25.32 ± 1.66㎜ and total wet weight 3.10 ± 0.54 g) to three pCO2 levels (i.e., 438.6, 738.3, 932.9ppm). Each experimental level was regulated by small vapor-liquid equilibrium system and CO2 concentration analyzer with non-Dispersive Infrared (NDIR) method. Eight clams were allocated in a jar with sediment by 4 replicates during 48 days. Our results show no significant difference on mortality, respiration rate and emerging behavior of individuals among three pCO2 levels. The results of this study indicate that near future level pCO2 does not seem to have a serious effect on behavior and physiology of adult Manila clams. CO2 level is expected to be from 421ppm (RCP2.6) to 936ppm (RCP8.5) in the year 2100. High atmospheric CO2 dissolves into the surface of ocean, lowers the pH of seawater and thus is expected to pose a potential threat to marine organisms, especially which have shells. We focused on the physiological and behavioral responses of adult Manila clams, Venerupis philippinarum (n = 96, shell length 25.32 ± 1.66㎜ and total wet weight 3.10 ± 0.54 g) to three pCO2 levels (i.e., 438.6, 738.3, 932.9ppm). Each experimental level was regulated by small vapor-liquid equilibrium system and CO2 concentration analyzer with non-Dispersive Infrared (NDIR) method. Eight clams were allocated in a jar with sediment by 4 replicates during 48 days. Our results show no significant difference on mortality, respiration rate and emerging behavior of individuals among three pCO2 levels. The results of this study indicate that near future level pCO2 does not seem to have a serious effect on behavior and physiology of adult Manila clams.