辽河口粪便污染指示菌的时空分布特征

2013年分别于夏季和秋季对辽河口海域的粪便污染指示菌(总大肠菌群、粪大肠菌群和肠球菌)及环境、水化学要素进行分析,研究粪便污染指示菌在海水中的数量、分布特征及其与环境、水化学指标间的相关性,在此基础上,选取河口地区合适的粪便污染指示菌.结果表明:夏季总大肠菌群数量在1.7×105~6.2×106CFU·L-1之间,粪大肠菌群数量在5.0×102~8.7×104CFU·L-1之间,肠球菌数量在1.0×101~2.5×102CFU·L-1之间;秋季总大肠菌群数量在5.0×102~1.1×105CFU·L-1之间,粪大肠菌群数量在4.0×102~1.0×103CFU·L-1之间,肠球菌数量在3~95 CFU·L-1之间.总大肠菌群、粪大肠菌群和肠球菌的数量变化与环境指标之间有着密切联系,特别是与盐度存在显著相关性;粪大肠菌群、肠球菌与水化学指标Si O4-4-Si、NH+4-N、TP和COD之间均存在显著相关性;其中粪大肠菌群与SiO4-4-Si和TP的相关性系数均大于0.742(p0.01),肠球菌与TP和COD的相关性系数均大于0.742.实验结果表明,辽河口粪便污染指示菌的数量在夏季高于秋季,近岸高于远海,其中粪大肠菌群和肠球菌的数量、分布特征与陆源污染物特别是氮磷的输入量密切相关,而且两者之间呈显著正相关关系.粪大肠菌群与肠球菌在一定程度上可以反映河口粪便污染情况,建议采用粪大肠菌群与肠球菌作为河口粪便污染的指示菌.

Spatial and temporal distribution of fecal pollution indicator bacteria in Liaohe estuary

The aim of this study was to investigate the abundance and distribution of fecal indicator bacteria in seawater and its correlation with environmental factors. In 2013, the fecal indicator bacterium (total coliforms, fecal coliforms and enterococci) and environmental factors were identified both in summer and autumn of Liaohe estuary. Based on this, we choose the proper indicator bacteria to present the fecal pollution. The results showed that in summer the number of total coliforms, fecal coliform and enterococci was between 1.7×10⁵~6.2×10⁶ CFU·L^-1, 5.0×10²~8.7×10⁴ CFU·L^-1 and 1.0×10¹~2.5×10² CFU·L^-1, respectively. While in autumn the number was between 5.0×10²~1.1×10⁵ CFU·L^-1, 4.0×10²~1.0×10³ CFU·L^-1 and 3~95 CFU·L^-1, respectively. Correlations were significant between the variations of the number of total coliforms, fecal coliform and enterococci, especially under salty condition. Fecal coliforms and enterococci were significantly correlated with water chemistry indicators SiO₄^4--Si,NH₄⁺-N, TP and COD. Correlation coefficient of fecal coliforms with SiO₄^4--Si and TP were both greater than 0.742(p<0.01), while those of enterococci with TP and COD were both greater than 0.742. The experiment results showed that the number of bacterial indicators in summer was higher than that in autumnand offshore higher than the far shore. At the same time, the number of fecal coliform and enterococci distribution was significantly correlated with land-based pollutants especially nitrogen and phosphorus inputs. In summary, the fecal coliform and enterococcus in estuarine area can reflect fecal pollution. Therefore, we suggest the fecal coliform and enterococcus should be used as indicators to evaluate fecal pollution in Liaohe estuary.