东海沿岸海域表层海水酸化趋势及影响因素研究

摘要

根据2002-2011年东海沿岸海域(4个区域,16个站位)春、夏、秋三个季节的表层海水pH、温度、盐度和叶绿素a等监测资料,对该海域pH的年际时空变化及其影响因素进行了探讨.结果表明,东海沿岸海域表层海水十年间pH变化趋势存在明显的季节和区域差异,共有10个站点表层海水pH呈下降趋势,主要集中于长江口和杭州湾海域,而三门湾和椒江口海域的酸化则不明显.环境因子相关性分析显示,杭州湾海域夏季表层海水的pH与叶绿素a浓度呈极显著正相关,其它海域两者间未显示出显著的相关性;杭州湾海域的pH与海表温度也存在显著的相关性,但季节不同趋势不同,呈现出春季正相关而夏季负相关的特征;pH与盐度的关系在各海域表现得更加明显,长江口、杭州湾和三门湾三个调查海区海水的pH变化与盐度都存在显著的正相关.总之,在10年的连续监测内东海沿岸海域存在一定程度的酸化趋势,其影响机制还需进一步研究.%Using 2002-2011 monitoring data of pH,temperature,salinity and chlorophyll a in spring,summer,and autumn in surface seawater of the coastal East China Sea in four areas and 16 sites,we studied the annual temporal-spatial variation of pH and the influencing factors.The results show that seasonal and regional variations in pH of the surface water in last 10 years was significant.The pH value decreased in 10 sites in the Changjiang (Yangtze) River estuary and Hangzhou Bay,but did not in the Sanmen Bay and Jiaojiang River mouth.Correlation analysis showed that,correlation between pH value and chlorophyll a concentration was significantly positive in the surface waters of Hangzhou Bay during summer,but not in other waters and seasons.The correlation between the pH value and sea surface temperature was significant in the Hangzhou Bay,but varied in seasonal trend:positive in spring and negative in summer.The correlation between pH and salinity was obvious in all waters:significantly positive in the Changjiang River estuary,Hangzhou Bay and Sanmen Bay.In conclusion,there was a certain degree of acidification trend in the coastal East China Sea within 10 years of continuous monitoring,the impact mechanism still need further study.