COMPARATIVE LIMNOLOGY AND THE EUTROPHICATION OF A WARM LAKE: LAKE AMATITLAN, GUATEMALA (NUTRIENT LOADING, TROPICAL)

Nutrient loading criteria, developed to evaluate eutrophication of water bodies in temperate regions, were used to investigate the trophic status of a warm lake in Central America, Lake Amatitlan. Furthermore, information from 28 lakes located in Central and South America was compiled in order to compare temperate and warm waterbodies and highlight the similarities and differences.; Based on this investigation, the same nutrient loading criteria cannot be used to define the trophic status of warm lakes because the warm lake responses to nutrient loadings are less dramatic than in temperate lakes. This is shown by the higher transparency and lower chlorophyll a values in the warm lakes compared to the temperate lakes for the same amount of nutrient loadings. Weather patterns affect the loadings and lake responses. Thus, a new trophic status of lakes and reservoirs has to be defined in order to account for the pseudo-eutrophic conditions shown by most of the warm waterbodies.; Lake Amatitlan's total-P and total-N loadings were estimated using export coefficients corrected for the slope of the land. The loadings predicted in that manner are in the range of values expected for a polluted river such as Rio Villalobos, which feeds Lake Amatitlan. By using the modified Vollenweider lake model, the mean lake total-P concentration was estimated, and is in agreement with the few reliable measurements of total phosphorus in Lake Amatitlan.