Dynamics of prokaryotic community in Boka Kotorska Bay (South-eastern Adriatic Sea)

Abstract

     The dynamics of the prokaryotic picoplankton community were studied at six stations of three embayments in Boka Kotorska Bay from January 2010 to January 2011. The abundance of non-pigmented bacteria, high nucleic acid content (HNA) bacteria, low nucleic acid content (LNA) bacteria, bacterial production and heterotrophic nanoflagellates was determined, as well as the chlorophyll a, physical and chemical factors of the water column. It seems that freshwater input has the ability to control bacterial abundance as well as the proportion of HNA cells in bacterial community and thus the abundance of HNF cells. During the warmer seasons, in the investigated area, which is mainly oligotrophic, we found an increase in values and domination of the LNA group in the bacterial population. The dominance of the HNA group was found only during the colder seasons. Weak coupling between bacteria and HNF suggests that predation (top down control) is not dominant in controling of bacterial abundance in studied area.