Thermotolerant coliforms (Canal da Passagem, Vitória ES): Temporal distribution related to tidal dynamics and physical chemical factors in a tropical estuary

The main objective was to describe the spatial and temporal distribution of thermotolerant coliforms in the Passagem Channel and relate them to physical-chemical and tidal data, which generally have considerable gradients in an estuary. In addition, it aimed to establish a relationship between distribution and specific sources of faecal pollution, compare the results with previous studies, and assess the sanitary quality of the environment. Samples were collected during the spring tide, at high and low tide. The physical-chemical data submitted to Spearman's correlation and linear regression were temperature, conductivity, dissolved oxygen, redox potential, pH, total dissolved solids and ammoniacal nitrogen, from which no significant correlations were obtained. There were significant correlations in relation to the tide. Tidal currents are the main forces responsible for the dynamics of the Canal. No significant temporal variability was observed, which can be attributed to the absence of rainfall in the days prior to the collections. The waters of the Passagem Canal are extremely affected by faecal contamination and are not suitable for any human use, except upstream.