APPLICATION OF TROPHIC STATE INDICES IN THE DAM OF SALTO GRANDE

Abstract

Eutrophication is the process by which nutrients, mainly phosphorus, are
contributed. Currently, this has increased due to human activity and population growth
which has caused the deterioration of water quality and limited its potential uses. In this
study, the trophic state of the Salto Grande Reservoir was determined in the stretch between
Monte Caseros/Bella Union and the dam, during the summer period of 2010 through the
application of different indices. Moreover, the representative blue green algae from the area
corresponding to the genera Microcystis and Dolichospermum and their relation to the nutrients
were studied. Nutrient concentrations, mainly phosphorus, were relatively high, determining
an eutrophic state from the area of study. Due to the flooding which began in November 2009,
the relative abundance of cyanobacteria was not high, with a maximum of approximately
40,000 cells/ml. Furthermore, no linear correlation was established between cyanobacteria
and the nutrients studied. We conclude that, as suggested by the records, nutrients would
not be a limiting factor for the proliferation of cyanobacteria in the reservoir area of Salto
Grande.