乳山湾邻近海域有机碳的分布与底界面过程  

Characteristics and benthic processes of organic carbon in the adjacent area of Rushan Bay

作　　者：臧家业[1] 赵晨英 刘军[1,2] 谢琳萍[1] 王以斌[1] 张爱军[1] 冉祥滨[1] 

机构地区：[1]国家海洋局第一海洋研究所,海洋生态研究中心,山东青岛266061 [2]国家海洋局第一海洋研究所,海洋地质与地球物理研究室,山东青岛266061

出　　处：《中国环境科学》2017年第3期1089-1102,共14页China Environmental Science

基　　金：中央级公益性科研院所基本科研业务费专项(GY0216Q03);国家自然科学基金(41376093,41106072)

摘　　要：根据2009年和2014年夏季在乳山湾口及邻近海域的综合调查结果,分析了该海域夏季有机碳的时空分布、底界面过程与影响因素.结果表明,2009年夏季乳山湾近海水体溶解有机碳(DOC)含量介于0.70~3.19mg/L之间,平均值为1.80mg/L;DOC的平均值在8月最高,7月与9月次之,6月最低;2014年8月份DOC的变化范围为1.79~15.2mg/L,高于2009年同期水平,颗粒有机碳(POC)的变化范围为0.04~1.33mg/L;水体有机碳的分布受陆源输入、海洋初级生产以及潮汐的显著影响.研究区域夏季颗粒有机碳(POC)的沉降通量为(25±0.8)g/m^2,约占初级生产固碳量的66%;沉积物上层(0~4cm)间隙水中DOC的浓度是沉积物上覆水的8~9倍,DOC在沉积物—水界面存在向上覆水释放的现象;乳山湾湾口DOC交换通量为14.4–97g/(m^2·a),占水体存量的1.1%~13.4%.人类活动一定程度上影响了乳山湾及其近海有机碳的构成与循环收支过程,是区域环境变化的重要驱动因子之一.有超过50%的有机碳会随潮流输送到外海,显示潮流在有机碳输送中巨大作用;沉积物-水界面DOC的交换会影响底界面有机碳的收支与循环过程,有机碳的收支表明研究海域底界面有机碳的降解所产生的溶解有机碳是水体DOC的重要来源,最终保存在沉积物中的碳其埋藏量约占初级生产的13%;相对较低的溶解氧水平可能会增加DOC的交换通量,影响碳在陆架边缘海的埋藏.Estuaries, lagoons and bays are considered as the most important ocean margins due to their important influence in land-sea interaction under human activities, playing key roles in the regional carbon biogeochemical cycles. Based on measurements obtained from comprehensive survey in the adjacent area of Rushan Bay in summer of 2009 and 2014, organic carbon（OC） distributions, its benthic processes and influence factors were determined. The results showed that the concentration of dissolved organic carbon（DOC） in summer 2009 ranges from 0.70 to 3.19mg/L, with an average concentration of 1.80mg/L. Concentration of DOC was high in August, and low in June. Time-dependent variation of DOC and particulate organic carbon（POC） were ranged in1.79～15.2mg/L and 0.04～1.33mg/L, respectively. DOC patterns were mainly affected by human activities, primary production and tide. Estimated POC sedimentation rate was（25±0.8） g/m2 in summer, accounting for 66% of the carbon fixation by phytoplankton related to primary production. DOC concentrations in the pore water of the upper sediment（0～4cm） were 8～9times larger than those in the overlying water, and benthic DOC flux at the sediment-water interface ranged from 14.4 to 97g/（m2a）, accounting for 1.1%～13.4% of DOC in the water DOC pool. Anthropogenic activities were the key factors that influence the OC distribution and cycling in the coastal areas of Rushan Bay. The OC budget shows that regeneration of sedimentary TOC contributes to a large share of diffusive DOC flux, indicating that the sediment is a significant source of DOC to water column in the study area. More than 50% of OC can be transported by tides and currents. The net burial of OC in sediments represents 13% of the carbon pool that yield by the primary production in summer. Low-oxygen level may enhance benthic diffusive of DOC and other diagenetic processes, which would play a key role in controlling OC conservation in the sediment.

关 键 词：乳山湾 有机碳 通量 初级生产 底界面过程 

分 类 号：X55[环境科学与工程—环境工程] P72[天文地球—海洋科学]