Establishing the pattern of heterotrophic bacterial activity in three Central Amazonian lakes

Three lakes of the Central Amazon were studied in depth for a year. Patterns of heterotrophic activity were seen to develop as the result of a variety of factors in the three lakes. Primary mechanisms that appear to control the heterotrophic activity were the water levels, the nutrient concentrations, including labile carbon, and the chlorophyll-a levels. Heterotrophic activity (V_max) in the three lakes varied from values comparable to extreme oligotrophic to eutrophic in each of the lakes studies. The large range (0.045–9.644 µg 1^–1 h^–1) of V_max is viewed as a part of the cycle of growth and renewal which is characteristic of the Central Amazonian Ria and Varzea lakes.