Epixilic algae from a lowland river from Buenos Aires province (Argentina)

RODRIGUEZ, P. L.; PIZARRO, H.; MAIDANA, N. I.; BONAVENTURA, S. M.; DOSANTOS AFONSO, M.

CRYPTOGAMIE. ALGOLOGIE

ADAC-CRYPTOGAMIE

Año: 2006 vol. 27 p. 63 - 83

0181-1568

We analysed the influence of the spatial and temporal variations of the physical and chemical properties of the water on the specific composition of the periphytic algae attached to wooden posts (epixylon) from a section of the low river Luján (Buenos Aires, Argentina) and of a tributary, subject to different degrees of exposure to  wastewater. Algae and water samples were taken nearly monthly from July 2000 to July 2001. During the study period, river Luján and its tributary had very poor water quality showing physical and chemical characteristics typical of polluted urban rivers. At all sites, Bacillariophyceae was the dominant algal Class in terms of richness followed by Cyanobacteria, Chlorophyta and Euglenophyta, and the taxa registered were typical of polluted rivers being some of them adapted to desiccation due to the strong fluctuations in the hydrological level of the river. The RDA analysis indicated that the species composition and richness exhibited a stronger response to the seasonal and spatial variability of the limnological characteristics of the system than to the inputs of domestic and/or industrial pollutants. This is probably the cause that the whole epixylic communities from the low river Luján was composed by algae adapted to polluted watercourses which are subject to frequent peaks of pollutants.