Algal Bioversity, Assessment of the Trophic Status of a Pampean Wetland

This work is part of a general project that includes the study of algal dynamics in lenitic systems in the province of La Pampa. The objective was to know and categorize the phycoflora of Laguna Ea. Ans?n, belonging to the Luan Lauquen system (Dpto. Capital). Biological, physical-chemical and seasonal environmental samplings were carried out between May and December 2011. Of the total number of species recorded, the Chlorophyceae class showed the highest specific richness with 86 taxa, followed by Cyanophyceae (32), Bacillariophyceae (23), Euglenophyceae (12) and Chrysophyceae (1). The degree of phycological community similarity throughout the sampling period ranged from 41.5 >= 47%. The results of the Nygaard indices applied qualify the lagoon as eutrophic, typical of the Pampean region, characterized by alkaline pH and low salinity waters. The saprophytic status of the basin (S= 2.32) established from the bioecology of the organisms classifies it within the β-mesosaprobic range of moderately polluted waters.