RESUMO
The aim of this work was to evaluate the microbial activity of the surface sediments (0-10 cm) of the Chacopata-Bocaripo lagoon axis (Ch-BLA) through microbiological parameters: microbial biomass (Cmic) dehydrogenase activity (DHS), fluorescein diacetate hydrolysis (HFDA), arginine ammonification (AA) and biochemical parameters: phosphatase (PHa) and urease (URa) activity. They were determined during transition (July 2010) and upwelling (March 2011) periods. Total organic carbon (TOC) did not vary significantly (p⩾0.05) between climatic periods. All the parameters studied were higher in upwelling season: Cmic (191.79 mg Cmic kg(-1)), DHS (228.70 µg TFF g(-1) 24 h(-1)), HFDA (204.09 µg fluorescein g(-1) 24 h(-1)), AA (13.09 µg NH4-N g(-1) h(-1)), PHa (132.31 µg pNF g(-1) h(-1)), URa (12.90 µg NH4-N g(-1) h(-1)). They appear to be controlled by the availability and quality of nutrients in each climatic period, and were useful tools for evaluating changes in microbial activity in marine sediments.