Background: Mazandaran province, with the largest coastline of the Caspian Sea in the country, draws a large number of travelers and tourists every year. This study aimed to determine and interpret the microbial health quality of its coastal waters. Methods: ۱۹ swimming points in Sari, Miandorud, Juybar, and Babolsar counties were weekly sampled for six months. Microbial testing for collected samples was performed using the MPN method and membrane filter based on EPA method ۱۶۰۰. The data were analyzed using SPSS software.  Descriptive, normality, one-way analysis of variance (ANOVA) and LSD tests were also conducted. Results: The mean of enterococcus in all the stations was standard; however, fecal coliform in P۴, P۱, and P۰ of Babolsar was high. Normality tests of geometric mean indices, normal distribution, and results of one-way analysis of variance between stations and sampling time showed a significant difference at the level of P < ۰.۰۵. The highest contamination was observed at P۴, P۱, P۰, Edalat ۴, and Farahabad. Conclusion: Due to the presence of microbial contamination in some areas, determining fecal coliform indicator in addition to enterococci is necessary to accurately estimate the status of microbial contamination of coastal waters in the region.

Keywords:

Coastal recreational waters , Fecal indicators , Caspian Sea , Mazandaran province