Fitobentos, fitoplancton y zooplancton litoral del bañado de Carilauquen, Cuenca de Llancanelo, Mendoza, Argentina

Abstract

The ecosystem under study represents one of the most important marshes in the Llancanelo wetlands, Mendoza Province, central western Argentina. The objective of this study was to analyse the planktonic and benthic communities as a measure of water quality, and the detection of the possible impact of oil-production on these communities. The research was carried out seasonally from summer 2001 to spring 2002. The marsh waters presented high concentrations of sulphates and carbonates. A conductivity gradient from the springs to the lake was observed (959 µS cm -1 - 10810 µS cm -1 ) which indicated a pattern of spatial and seasonal distribution of the studied communities. Diatoms dominated the algal groups and were the most abundant and diverse in the benthic fraccion. Regarding the zooplankton, shelled amoebas were the most abundant in the zooplankton community, followed by rotifers, ostracods, and ciliates. According to the environmental requirements of the species found, this marsh is defined as eutrophic and polysaprobic, characterized by a high organic matter load. Hydrocarbons were detected in the water in two sampling areas in the winter and spring seasons. Therefore it is hypothesised that this pollutant may be the cause of the marked reduction in planktonic ‐ benthic diversity and the proliferation of cyanophyte algae known to be toxic.