Periphyton responses to non-point pollution in a natural eutrophic condition in Pampean streams

CAROLINA VILCHES; ADONIS GIORGI; CASCO, M. A.

FUNDAMENTAL AND APPLIED LIMNOLOGY

E SCHWEIZERBARTSCHE VERLAGS

Lugar: Stuttgart; Año: 2013 vol. 183 p. 63 - 74

1863-9135

The aim of this study was to know the effects of different intensities of non-point pollution on the water quality and the periphyton community in natural eutrophic environments as the Pampean streams. Non-point pollution produced by agricultural and farm activities are an important contributor to water quality deterioration. Our hypothesis was that, in spite of the natural water eutrophication of the pampean streams, the pollution generated by rural activities promote changes in water quality modifying nutrient concentrations and promoting or inhibiting the periphyton developed depending of kind and intensity of land use. The more important periphyton parameters to assess the non-point pollution effect due to rural activities estimated were chlorophyll-a, net production and alkaline phosphatase activity. The water quality parameters useful to differentiate rural activities were soluble reactive phosphorus and conductivity. Agriculture caused an increase of authotrophic biomass and then increases net production whereas cattle farming caused an increase of heterotrophic biomass. The chlorophytes were abundant in agricultural zones whereas cyanophytes or euglenophytes were more abundant in the cattle farming areas. Thus, periphyton could be used as indicator of non-point pollution, differentiating not only the types kinds of activit but also their persistence and the intensity of rural practices.