Bacteria and phytoplankton production rates in eight river stretches of the middle Rio Doce hidrographic basin (Southeast Brazil)

Abstract

Measurements of bacterial secondary production (BSP), together with primary phytoplanktonic production (PPP) were conducted during dry and rainy seasons, in eight rivers of different orders submitted to different degrees of human impacts (different trophic degree). We aimed to determine and compare the importance of BSP and PPP in carbon fixation in these different lotic ecosystems. Our results showed that the Ipanema River was the most modified system by anthropogenic effluents inputs. These inputs altered the trophic degree and BSP rates of these streams and rivers.