江门市近岸海域春季环境质量评价

Evaluation on environmental quality of Jiangmen near-shore waters in spring

2016年4月对江门市近岸海域水质、表层沉积物、浮游动植物和底栖生物进行了调查研究。水质调查结果表明:除COD、BOD5、SS、无机氮(DIN)、活性磷酸盐(DIP)、铅、铜和镍外,其他项目均符合《海水水质标准》(GB 3097—1997)第二类标准;其中,COD、SS、DIN和DIP超出GB 3097—1997第四类标准。水体富营养化指数和有机污染评价指数显示,近期江门市近岸海域总体呈重度富营养状态,部分海域甚至呈严重富营养状态,有机污染严重。表层沉积物调查结果表明,依据《海洋沉积物质量》(GB18668—2002)第一类标准,调查海域表层沉积物中铜和有机质超标严重,超标率达100.0%;表层沉积物已经受到重金属污染。浮游植物共有55种,以硅藻门占绝对优势;浮游动物共有42种,优势种仅有夜光虫(Noctiluca);底栖生物有16种,绝对优势种为小头虫(Capitella capitata)。研究发现,调查海域在春季存在甲藻赤潮和夜光虫赤潮暴发的风险。底栖生物的丰度和生物量与表层沉积物中污染物的相关性分析表明:丰度与铬呈显著正相关;生物量与锌呈显著正相关,与铜接近显著正相关。

The investigation was conducted on ocean environmental quality in Jiangmen near-shore waters in April 2016,including seawater quality,surface sediment,phytoplankton,zooplankton and benthos.The survey results of seawater quality showed that in addition to COD,BOD5,SS,DIN,DIP,Pb,Cu and Ni,the other monitoring factors met ClassⅡ standard of＂Sea water quality standard＂（GB 3097-1997）.The concentrations of COD,SS,DIN and DIP even exceeded the ClassⅣ standard of GB 3097-1997.The results of eutrophication index and organic pollution index showed that the coastal areas of Jiangmen was in a heavy state of eutrophication,and some areas even showed serious eutrophication with serious organic pollution.The survey results of surface sediment showed that the over-standard of Cu and organic matter was serious in Jiangmen coastal area.The over-standard rates of Cu and organic matter based on ClassⅠ of＂Marine sediment quality＂（GB 18668-2002）reached to 100.0%.Surface sediment had been polluted by heavy metals.A total of 55 species of phytoplankton were identified,dominated by Bacillariophyta.A total of 42 species of zooplankton were identified with the only dominant species Noctiluca.A total of 16 species of benthos were identified with the absolute dominant species Capitella capitata.The study found that there was a risk of Dinoflagellates red tide and Noctiluca red tide in investigation near-shore waters in spring.Correlation analysis showed that benthos abundance was significantly positively correlated with Cr;benthos biomass was significantly positively correlated with Zn,and nearly significantly positively with Cu.