摘要
受气候变化和人类活动的影响,传输和沉降到全球近海的大气污染物急剧增加。1997年后对近海营养盐和微量元素大气沉降的众多研究表明,通过大气沉降至近海的氮和磷分别为13~73mmol N/(m2.a)和0.11~1.6mmolP/(m2.a),微量元素的沉降通量具有显著的时空变化特征,在不同海区最高可相差3个数量级。对于很多近海包括东海(East China Sea)和黄海(Yellow Sea),大气沉降的营养盐和部分微量元素可能超出了其河流输入量。大气沉降除了对近海富营养化有重要贡献之外,其事件性特征可使初级生产力在短期内大幅度增加,从而影响赤潮发生。微量元素沉降还可能抑制某些藻类生长,对初级生产力和生态系统结构产生更为复杂的影响。未来研究重点是准确估算近海各物质的大气沉降通量,了解其对浮游植物生长的影响机制。
Atmospheric transport and deposition of pollutants to the coastal oceans increase dramatically due to the impacts of climate change and human activities. The paper summarizes a number of researches after 1997 on the atmospheric inputs of nutrients and trace elements to the world coastal oceans with emphasis on the eastern China seas. The atmospheric fluxes of nitrogen and phosphorus to the coastal oceans range from 13 to 73 mmol N /( m^2·a) and 0. 11 to 1. 6 mmol P /( m^2·a) ,respectively. North Sea appears to be influenced by relatively higher atmospheric flux of nitrogen ( 70 mmol N /( m^2·a) ) compared to the eastern coast of North America ( 50 mmol N / ( m^2·a) ) and eastern China seas ( 50 mmol N /( m^2·a) ). Mediterranean Sea and the Gulf of Aqaba ( Red Sea) receive the lowest fluxes of nitrogen as well as phosphorus from the atmosphere. The deposition fluxes of trace elements vary significantly in both time and space with the highest flux approximately 3 orders of magnitude higher than the lowest one. The flux variations of crustal-dominated trace elements such as Al and Fe are strongly related to the dust transport and agricultural activities of adjacent land,while atmospheric fluxes of non-crustal trace elements like Cd,Zn and Pb are mainly determined by industrial and mobile emissions. Atmospheric inputs of trace elements can partly dissolve into the seawater with the solubility ranging from a few percent to 〉50% and that portion may become bioavailable and thereby influence the costal ecosystem. For many coastal oceans including East China Sea and Yellow Sea,atmospheric fluxes of nutrients and certain trace elements may exceed their riverine inputs. Atmospheric deposition contributes significantly to the coastal eutrophication,and its episodic nature can enhance primary productivity within a short period,which may induce a harmful algal bloom ( red tide). Trace element deposition may have toxic effects on specific phytoplankton and influence both primary productivity and ecosystem structure of the coastal area. Further studies should be conducted for accurate estimation of atmospheric fluxes of various pollutants to the coastal oceans and for understanding their roles in marine phytoplankton growth.
出处
《地球科学进展》
CAS
CSCD
北大核心
2010年第7期682-690,共9页
Advances in Earth Science
基金
上海市浦江人才计划"东中国海的大气沉降及其对近海环境和全球变化的可能影响"(编号:09PJ1401200)
国家教育部博士点新教师基金项目"大气沉降对富营养化淡水湖中微蘘藻毒素浓度的影响机制"(编号:20090071120007)资助
关键词
近海
大气沉降
营养盐
微量元素
富营养化
Coastal Ocean
Atmospheric deposition
Nutrients
Trace elements
Eutrophication.