Seasonal Variations of Total Coliform and Fecal Coliform in the Lagoon Seawater of Shanghai Jinshan City Beach in North Hangzhou Bay

Abstract

To investigate the hygienic quality of the lagoon seawater in Shanghai Jinshan City Beach (30°42 22 -30°43 06 N 121°20 40 -121°21 24 E) of North Hangzhou Bay, total coliform and fecal coliform was analyzed monthly from August 2006 to July 2007. The results showed that the densities of total coliform was no more than 1400MPN/L,the concentration is higher in July, August and September, the highest concentration of total coliform reached 1400MPN/L in September, after that, it began to decline. Monthly average fecal coliform was no more than 940MPN/L all the year round, likewise, it was relatively higher in July, August and September, but lower in winter and spring, with a lowest concentration of 20MPN/L,the highest concentration was 940MPN/L in September. From the regression analysis, it showed that coliform was positively correlated with fecal coli-group, their correlation coefficient was 0.7934. In addition, some environmental parameters including physical and chemical properties of seawater quality were also investigated. The environmental parameters were not positively correlated with both total coliform and fecal coliform. According to the Sea Water Quality Standard (GB3097-1997), the quality of seawater in Shanghai Jinshan City Beach was classified as the Second Grade and might be suitable for opening beach recreation park including swimming and other water direct contact activities.