2000—2015年大鹏湾中5日生化需氧量的时空分布  

Temporal and Spatial Distributions of 5-day Biochemical Oxygen Demand in the Mirs Bay

作　　者：林梵[1] 李绪录[1] 许春玲[1] 史华明[1] LIN Fan;LI Xulu;XU Chunling;SHI Huaming(South China Sea Marine Survey and Technology Center, State Oceanic Administration, Guangzhou 510300, China)

机构地区：[1]国家海洋局南海调查技术中心,广东广州510300

出　　处：《生态环境学报》2017年第5期883-889,共7页Ecology and Environmental Sciences

基　　金：国家海洋局南海分局海洋科学技术局长基金项目(1523;1524);国家"908"专项(908-02-02-03)

摘　　要：生物可利用有机物影响着全球海洋和沿岸水域中浮游生物的群体组成、种类分布、生产力及生态系统结构。依据2000—2015年每月1次的调查资料,分析了大鹏湾中5日生化需氧量(5-day biochemical oxygen demand,BOD_5)的时空分布,并结合叶绿素a(Chlorophyll a,Chl a)、颗粒有机物(Particulate organic matter,POM)和溶解有机氮(Dissolved organic nitrogen,DON)实测数据,应用回归分析法分析了BOD_5与它们之间的关系,研究了各形态有机物的稳定性和生物可利用性。研究期间,大鹏湾中ρ(BOD_5)为(1.1±0.8)mg·L^(-1),表层高于底层,春、夏季高于秋、冬季,年际变化略呈下降趋势,从2000年的1.2 mg·L^(-1)下降至2015年的1.0 mg·L^(-1)。由于受到香港和深圳人为排放的影响,吐露港内和沙头角附近水域的ρ(BOD_5)明显高于大鹏湾主区。3—4月和7—8月表层ρ(BOD_5)上升幅度较大,表明这些时期不稳定有机物(Labile organic matter,LOM)在表层水中积累。研究海区中表层ρ(Chl a)与ρ(BOD_5)之间关系密切,初级生产过程中LOM释放率约为134 g·g^(-1)(LOM/Chl a),而LOM滞留时间约为4.2 d。ρ(BOD_5)分别与ρ(POM)、ρ(DON)之间均存在着密切的线性正相关,显示POM和DON被微生物降解的速率分别与ρ(POM)和ρ(DON)呈正比。大鹏湾水体中溶解有机物比POM更最稳定,POM和DON的生物利用率分别约为24.6%和28.5%,与珠江口中盐度(S为20~30)混合区中实测溶解有机碳生物利用率相近。研究表明,吐露港内和沙头角附近水域的生态环境质量分别受到香港和深圳人为排放的影响比较严重。Bioavailable organic matterimpacts community composition,species distribution and productivity of plankton andecosystemic structures in the global open oceans and coastal waters.Data obtained monthly from2000to2015were used foranalyzing temporal and spatial distributions of5-day biochemical oxygen demand(BOD5)in the Mirs Bay,the northern South ChinaSea.Also correlation of the BOD5with the chlorophyll-a(Chl-a),particulate organic matter(POM)and dissolved organic nitrogen(DON)mass concentrations,bioavailability and stability of the various forms of organic matter were investigated by a regressionanalysis method in combination with the measurements in the field.The mass concentration of BOD5was(1.1±0.8)mg·L-1in the bayduring the period studied.It was higher at the surface than the bottom and also higher in the spring and summer than the autumn andwinter.The inter-annual variability of the BOD5witnessed a decrease trend in thebay from2000to2015.The seaward dischargesfrom the cities of Hong Kong and Shenzhen caused the BOD5to be muchhigher in the inner Tolo Harbour and Shatoujiao adjacentwatersthan the main zone of the bay.The surface BOD5increased largely from March to April and July to August,implying thatlabile organic matter(LOM)accumulated in the surface-water during the periods.The surface Chl-a concentration found to beclosely correlated with the BOD5,the release rate of LOM about134g·g-1(LOM/Chl a)during the phytoplankton productionprocesses,and the residence time of LOM about4.2d in the bay.The BOD5was correlated well with the POM and DON respectivelyin a positive linearity,revealing that degradation rates of the POM and DON were proportional to the POM and DON concentrationsin the waters studied.The POM was found to be more unstable than the dissolved organic matter.The bioavailability of both POMand DON was respectively estimated for about28.5%and24.6%in the bay,nearly equal to thedissolved organic carbonbioavailability observed in the mixing zone with middle salinity(20to30)in the Pearl River Estuary.Th

关 键 词：5日生化需氧量时空分布 不稳定有机物滞留时间 有机物生物利用率 大鹏湾 

分 类 号：X131.2[环境科学与工程—环境科学]