Characterisation of mucilage aggregate in Adriatic and Tyrrhenian Sea: structure similarities between mucilage samples and the insoluble fractions of marine humic substance

The appearance of gelatinous aggregates called mucilages causes serious damages to tourism and fishery industries of the Adriatic Sea. So, many studies have been planned and some of them are still in progress to clarify the origin and causes of the phenomenon. The scientific research has showed that mucilages are produced by several marine organisms when peculiar climatic and trophic conditions occur. Moreover, as far as the mucilage composition is concerned, although it is well known that polysaccharides give a high contribution, knowledge of the structural characteristics of mucilages and their relationship with the natural organic matter of the marine environment has not been clarified yet. In this paper a study on the characterization of the marine mucilage samples collected in the Adriatic and Tyrrhenian Seas is described. The study was performed by spectroscopic (infrared and colorimetric) techniques, and elemental analysis. The results showed that mucilage samples have chemical and structural similarities with the insoluble fraction of the marine humic substance (humin). According to experimental evidences it is possible to establish the relationship between mucilages and the dissolved organic matter (DOM) in the marine environment in order to identify the most likely pathways of mucilage formation.