Based on variations of pelagial dissolved inorganic carbon (DIC) concentrations this article provides estimations of net primary productivity and net mineralization -- net carbon metabolism -- in Cima Lake (Rio de Janeiro State). DIC concentrations varied from 203 to 773 µmol L-1 and %CO2(aq) (saturation) from 339 to 4,901. Net carbon metabolism per light/dark periods from the 36 hours of study ranged, respectively, from -556 to 503 mmol DIC m-2 12 h-1. Marked variations in daily net carbon metabolism of the lake were also observed. The values ranged from -25 to -194 mmol DIC m-2 day-1. The findings were discussed as indicators of dynamic biological behavior toward production or mineralization of organic matter in the system. And, the system seemed to... |