RESUMO
During the EOCUMM '94 cruise, 15 stations located in the Eolian Islands area (Southern Tyrrhenian Sea) were sampled to analyse the distributions of the total bacterioplankton densities and the heterotrophic viable bacteria counts on Marine Agar 2216. According to the TS (temperature-salinity) diagrams, obtained by processing the CTD (conductivity-temperature-depth) vertical profiles, the sampled stations were grouped in "hydrological clusters". The bacteriological variables, together with the chlorophyll a and the particulate organic carbon measures obtained during the same cruise were used to compare the stations of the same and different clusters. The results indicated that variabilities of the analysed microbial parameters were not obviously related to the hydrographic features of the sampling stations. This work is an attempt to verify the possibility of using microbial parameters to characterize the structure of the water column.