大沽河河口潮滩表层沉积物中有机物的时空分布特征

Spatio-temporal characteristics of organic matters of surface sediment in tidal flats of the Daguhe Estuary

为明确胶州湾大沽河河口潮滩贝类底播养殖区生态功能退化的原因,2009年2月、5月、8月和11月,在该潮滩采集表层沉积物样品,分析其中有机物的质量分数并评价表层沉积物的环境质量。结果表明:2月,非底播潮滩、底播潮滩和河道的表层沉积物中有机物的质量分数分别是7.35%、6.00%和4.12%;5月,上述区域表层沉积物中有机物的质量分数分别为1.90%、6.67%和3.29%;8月,表层沉积物中有机物的质量分数分别为1.66%、5.69%和3.71%;11月,表层沉积物物中有机物的质量分数分别为1.88%、4.20%和4.94%。贝类养殖潮滩表层沉积物的环境质量在5月为三类水平,在2月、8月和11月属二类;非养殖潮滩在2月属三类水平,在5月、8月和11月属一类;河道在2月、11月属二类水平,在5月、8月属一类。因此,潮滩底播养殖区生态功能退化源于表层沉积物中过多有机物质的积聚,在2月,贝类食物短缺也是其成因。

In order to make certain the right reason that caused the degradation of ecological function of tidal flats in the Daguhe Estuary for the bottom sowing enhancement,surface sediment cores were sampled in February,May,August and November of 2009.Furthermore,the organic matters content of these sediments were measured and the environmental quantities of sediments were assessed.In February,the organic matters content of sediments in the tidal flat without benthic shellfish culture,the tidal flat with benthic shellfish culture and the river way was 7.35%,6.00% and 4.12%,respectively.In May,it was 1.90%,6.67% and 3.29%,respectively.The organic matters content of sediments in August in these areas was 1.66%,5.69% and 3.71%,respectively.Nevertheless,in November,it was 1.88%,4.20% and 4.94%,respectively.The environmental quantity of sediments in the tidal flat with benthic shellfish culture belonged to the third level in May and it belonged to the second level in other sampling months.Nevertheless,the environmental quantity of sediments in the uncultured tidal belonged to the third level in February and belonged to the first level in May,August and November.The environmental quantity of sediments in the river way belonged to the second level in February and November.In May and August,it belonged to the first level.It was the accumulation of organic matters leading to the decline of the growth rate and the increase of mortality rate of cultured shellfish.Besides that,the shortage of food affected these shellfish.