粤东大规模海水增养殖区柘林湾表层沉积物中的含水量、有机质、氮和磷  

Sediment water,organic matter,nitrogen and phosphorus contents in a large-scale mariculture located in Zhelin Bay,eastern Guangdong Province,China

作　　者：黄长江[1] 董巧香[1] 林俊达[1] 商栩[1] 李金[1] 

机构地区：[1]温州医学院环境与公共卫生学院,浙江温州325035

出　　处：《海洋学报》2008年第2期38-50,共13页

基　　金：温州市科技局重大项目(S20060023);温州医学院重大项目(XNK0b008)

摘　　要：柘林湾是粤东地区规模最大的海水增养殖区,近20年来水体富营养化情况日益加重,赤潮频繁发生。2002年7月至2003年7月对该湾9个站位表层沉积物中的含水量(W)、有机质(TOM)和不同形态的氮(TkN,NH4+)与磷(Ex-P,Fe-P,Au-P,De-P,OP)进行每月一次的周年调查。结果显示,表层沉积物中的含水量和有机质及不同形态的氮、磷均呈现极显著意义的正相关关系,今后可用含水量直接对这些指标进行粗略估算。有机质与氮、磷呈显著意义的正相关关系,表明有机质是影响氮、磷含量和分布的重要因素之一。凯氏氮(TkN)和总磷(TP)的总平均值分别为(1 113.1±382.5)μg/g和(567.2±223.3)μg/g,显著高于国内外许多同类型的海湾。各形态氮、磷含量年均值的平面分布呈现湾内(除S1,S7站外)高于湾外、养殖区高于非养殖区、网箱渔排养殖区高于牡蛎养殖区的总体趋势,说明湾内大规模增养殖业对海湾富营养化进程起着重要的作用。各形态氮、磷含量均于盛夏至初秋的高温季节(7-9月)处于年度峰值,这与该季节养殖动物处于生长旺期与高死亡率所造成的生物碎屑增多和有机质分解加速有关。与2002年7月相比,2003年7月的TkN和TP均出现大幅升高,与水体富营养化程度不断加重的趋势相符。此外,自生磷(Au-P)年平均占TP的49.2%,是该湾沉积物中最主要的磷形态。由于水体富营养化能导致沉积物的pH降低,继而促进Au-P中的自生钙氟磷灰石和碳酸钙所结合的磷释放进入水体,因而表层沉积物中高浓度的Au-P可能成为此类海湾富营养化水平加剧和赤潮大规模暴发加剧的隐患。Zhelin Bay is one of the most important bays China. Due to the increasing human population and the for large scale mariculture in Guangdong Province, expanding mariculture in the last two decades, the ecological environment has greatly changed with frequent harmful algal blooms. We conducted a monthly survey of water content （W）, organic matter （TOM）, and various forms of nitrogen （N） and phosphorous （P） in the sediment from July 2002 to July 2003. The results show that water content correlated highly significantly with TOM and various forms of N and P and can be used as proxy for quick and rough estimate of these factor in the future surveys. TOM also correlated significantly with various forms of N and P, indicating that it is one of the key factors to affect the concentrations and distributions of N and P in the investigated waters. Average total Kjeldhal nitrogen （TkN） and total phosphorus （TP） was （1 113.1±382.5）μg/g and（567. 2±223.3）μg/g, respectively, much higher than those of similar estuaries in China and else- where. Average N and P tended to be higher inside than outside the bay, higher at aquaculture than non- aquaculture areas, and higher at fish-cage culture than oyster culture areas, suggesting that large-scale mariculture inside the bay play an important role in the eutrophication of Zhelin Bay. Various forms of N and P concentrations were higher during the warm season （July--September）, due to the increased decomposition and concentration of organic matter resulted from the fast growth and high mortality of the cultured species. Compared to July of 2002, TkN and TP were much higher in July of 2003, in consonance with the eutrophication of the Zhelin Bay. Since BP （biologiccal phosphorus） in the sediment includes Ex- P （exchangable phosphorus）, Fe--P （iron-- bouned phosphorus）, OP （organic phosphorus） and some Au-P （authigenic phosphorus）. Since Ex-P, Fe-P and OP combined accounted for 34.3% of the TP and Au-P accounted for 49.2% of the T

关 键 词：柘林湾 表层沉积物 氮 磷 含水量 有机质 

分 类 号：P734.61[天文地球—海洋化学]