College of Fisheries and Life Science, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China; Shanghai University Knowledge Service Platform, Shanghai Ocean University Aquatic Animal Breeding Center (ZF1206), Shanghai 201306, China.
College of Fisheries and Life Science, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China.
Sci Total Environ. 2015 May 1;514:261-72. doi: 10.1016/j.scitotenv.2015.01.092. Epub 2015 Feb 7.
Anthropogenic CO₂ emissions have caused seawater temperature elevation and ocean acidification. In view of both phenomena are occurring simultaneously, their combined effects on marine species must be experimentally evaluated. The purpose of this study was to estimate the combined effects of seawater acidification and temperature increase on the energy budget of the thick shell mussel Mytilus coruscus. Juvenile mussels were exposed to six combined treatments with three pH levels (8.1, 7.7 and 7.3)×two temperatures (25 °C and 30 °C) for 14 d. We found that clearance rates (CRs), food absorption efficiencies (AEs), respiration rates (RRs), ammonium excretion rates (ER), scope for growth (SFG) and O:N ratios were significantly reduced by elevated temperature sometimes during the whole experiments. Low pH showed significant negative effects on RR and ER, and significantly increased O:N ratios, but showed almost no effects on CR, AE and SFG of M. coruscus. Nevertheless, their interactive effects were observed in RR, ER and O:N ratios. PCA revealed positive relationships among most physiological indicators, especially between SFG and CR under normal temperatures compared to high temperatures. PCA also showed that the high RR was closely correlated to an increasing ER with increasing pH levels. These results suggest that physiological energetics of juvenile M. coruscus are able to acclimate to CO2 acidification with a little physiological effect, but not increased temperatures. Therefore, the negative effects of a temperature increase could potentially impact the ecophysiological responses of M. coruscus and have significant ecological consequences, mainly in those habitats where this species is dominant in terms of abundance and biomass.
人为 CO₂ 排放导致海水温度升高和海洋酸化。鉴于这两种现象同时发生，必须通过实验评估它们对海洋物种的综合影响。本研究的目的是估计海水酸化和温度升高对厚壳贻贝 Mytilus coruscus 能量预算的综合影响。将幼贻贝暴露于六个具有三个 pH 值（8.1、7.7 和 7.3）×两个温度（25°C 和 30°C）的组合处理中 14 天。我们发现，清除率（CR）、食物吸收率（AE）、呼吸率（RR）、氨排泄率（ER）、生长范围（SFG）和 O:N 比因高温而有时在整个实验中降低。低 pH 值对 RR 和 ER 有显著的负面影响，并显著增加了 O:N 比，但对 M. coruscus 的 CR、AE 和 SFG 几乎没有影响。然而，在 RR、ER 和 O:N 比中观察到了它们的交互作用。PCA 揭示了大多数生理指标之间的正相关关系，尤其是在正常温度下与高温相比时，SFG 和 CR 之间的正相关关系。PCA 还表明，高 RR 与 pH 值升高时 ER 的增加密切相关。这些结果表明，幼年 M. coruscus 的生理能量学能够适应 CO2 酸化，生理影响较小，但不能适应温度升高。因此，温度升高的负面影响可能会对 M. coruscus 的生理生态响应产生影响，并产生重大的生态后果，主要是在那些该物种在丰度和生物量方面占主导地位的栖息地。
