Evaluación del impacto ambiental sobre las comunidades de protozoos en la desembocadura del Rio Almendares, Ciudad de la Habana, Cuba.

Abstract

One of the practical utilities of the protozoa resides in their employment as biological indicators of the degree of environmental contamination. In this work a characterization of the protozoa community is made in the outlet of the river Almendares, which constitutes the most important fluvial current in the Cuban archipelago from the historical point of view, for they were selected it five stations that they were randomized monthly for a two year-old period (1996-1998). Of the 100 identified species 34 constitute new registrations for this segment of the river. The biggest specific richness corresponded to the ciliates, representing 67% of the total of species. The smallest specific richness corresponded to the estuary, where species are included restricted to brackish habitats and others of great ecological plasticity. Three species were collected exclusively in this place: Oxyrrhis marina (Mastigophora), Euglypha acantophora (Sarcodina) and Stentor coeruleus (Ciliophora). The bacteriophage characterized to most of the species of the community, although the presence of other alimentary alternatives as the protozoa microdepredation and algae, suggests the existence of certain complexity in the alimentary web for the presence of species of niche wide trophic. The temperature of the water and the of dry and rain periods didn't influence significantly in the richness of species, the absence of a marked estacionality in the behavior of the protozoa community can be due to the qualitative analysis carried out in function of the richness of species. The seasonal answer is possibly reflected in the populational densities of certain species, whose fluctuations are dependent of the analyzed factor. The number of species is relatively high if it is considered that the figure offered in an investigation carried out in the previous decade in this same area was of 64. As the contamination diminishes the changes are reflected in this parameter, so that the protozoa presence is considered as sign of flowing not very polluted. The tendency for the recovery of the quality of the waters of the river, had been shown.