Coliform enumeration in mussel-growing waters from Niteroi city, RJ-Brazil

Water samples from five different sites on Guanabara Bay (Icarai, Boa Viagein, Santa Cruz, Piratininga, and Rio Branco) were analyzed for estimated numbers of coliform and Escherichia coli. Water pH, salt concentration. and temperature were measured in the sampling place. E. coli countings for samples collected in Icarai, Boa Viagem, and Santa Cruz were usually higher than the values legally accepted by the Brazilian Ministry of Agriculture. In Piratininga and Rio Branco, respectively, 923% and 100% of the samples had countings of less than 3 E. coli/100ml. A significant correlation was found between total coliforms and E. coli countings. The average water temperature and pH were equal in the investigated sites. By contrast, water salinity, total coliforms, and E. coli counts were statistically equal in Icarai, Boa Viagem, and Santa Cruz, but different when compared to samples collected in Piratininga and Rio Branco. Nevertheless, samples collected in Piratininga and Rio Branco were statistically similar in these two sites. Results indicate that water from Icarai, Boa Viagem, and Santa Cruz are unsuitable for cultivating and/or harvesting bivalves for human consumption.