Seasonal dynamics of bacterial communities in a highly polluted coastal lagoon: Dominance of sulfur bacteria in response to elevated HS levels.

This study aims to evaluate the effects of different environmental gradients and seasonality on the bacterial communities of an impacted coastal lagoon. While the community compositions were homogenous in surface waters with the dominance of Candidatus Pelagibacter, diversity showed high vertical variation due to salinity and dissolved oxygen gradients. Anoxic conditions occurred at deeper parts of the lagoon, particularly at 14 m and 18 m, where nutrient enrichment and high HS concentration were detected resulting in a shift of bacterial community to anoxic species.