The aim of this paper was to determine the abundance and secondary production by bacteria inhabiting the surface microlayer and subsurface water in a specific water basin, i.e., polluted estuarine harbour channel. In a 3-year seasonal cycle, the total number of bacteria and their biomass were higher in the surface microlayer (SML) 7.57 × 108cells dm-3 and 15.86 µg C dm-3 than in the subsurface water (SSW) 4.25 × 108cells dm-3 and 9.11 µg C dm-3 of the studied channel. The opposite relationship was noted in the level of the secondary production (SML-37.16 μg C dm-3 h-1, SSW-60.26 μg C dm-3 h-1) in this water basin. According to the analysed microbiological parameters, the total number of bacteria and secondary production varied along the horizontal profile in the water of the studied channel. The total number of bacteria and their secondary production showed the seasonal variation as well.
Keywords: Bacterial production; Harbour channel; Subsurface water; Surface microlayer; Total bacterial number.
© 2021. The Author(s).