Some observations about bacterial presence in seawater related to mucilaginous aggregates in the Northwest Adriatic Sea

Mucus aggregates are an ubiquitous physiological component in marine waters, but there is uncertainty about their ecological role and its relationship to heterotrophic activity. To this end a preliminary investigation was initiated that considered bacterial density and its bearing on the presence or absence of such aggregates in the form of ‘marine snow’ in seawater. Bacterial density was found to increase by at least one order of magnitude in the presence of mucus aggregates compared with clear water. Implications and speculations regarding the role of bacteria as potential producers of viscous exopolymers and their possible role in the formation of mucus aggregates are discussed.