PRODUCCIóN PRIMARIA EN UN LAGO DE AGUAS CLARAS DE LA AMAZONíA COLOMBIANA (LAGO BOA)

phytoplankton production is one of the most significant aspects in aquatic ecosystems. in this paper primary production of the phytoplankton community was measured (14c method) in a clear water lake in the colombian amazon region in different periods of the hydrological cycle. primary production varied between 0.6 and 2.3 g c m-2 d-1, the last recorded at low water phase. results show that the phytoplankton community of lake boa fluctuates from very low capacity of carbon assimilation during high water but increased four times during low water. the strong change in productivity follows the variation in algal abundance, which in turn reflects changes in water quality conditions during the hydrologic cycle. thus, the lake passes from oligotrophic conditions during the flooding period to eutrophic conditions when the lake is disconnected from the river at low water phase.