Our data on the temperature, nutrient concentrations, pH range, dissolved oxygen values, and Secchi transparency were in general in agreement with limnological characteristics of Colombian and other tropical water bodies ('บmafia and Collado 1990; Suarez-Morales et al. 1993; Paaby 1995; Lopez-Lopez and Serna-Hernandez 1999; Gonzalez et al. 2002; Ramirez et al. 2002).