6533b7d8fe1ef96bd1269b74

RESEARCH PRODUCT

Shared effects of organic microcontaminants and environmental stressors on biofilms and invertebrates in impaired rivers

subject

description

Land use type, physical and chemical stressors, and organic microcontaminants were investigated for their effects on the biological communities (biofilms and invertebrates) in several Mediterranean rivers. The diversity of invertebrates, and the scores of the first principal component of a PCA performed with the diatom communities were the best descriptors of the distribution patterns of the biological communities against the river stressors. These two metrics decreased according to the progressive site impairment (associated to higher area of agricultural and urban-industrial, high water conductivity, higher dissolved organic carbon and dissolved inorganic nitrogen concentrations, and higher concentration of organic microcontaminants, particularly pharmaceutical and industrial compounds). The variance partition analyses (RDAs) attributed the major share (10%) of the biological communities' response to the environmental stressors (nutrients, altered discharge, dissolved organic matter), followed by the land use occupation (6%) and of the organic microcontaminants (2%). However, the variance shared by the three groups of descriptors was very high (41%), indicating that their simultaneous occurrence determined most of the variation in the biological communities This study has been financially supported by the EU through the FP7 project GLOBAQUA (Grant agreement No 603629). The authors are part of the Consolidated Research Groups of the Generalitat de Catalunya (2014 SGR 291dICRA and 2014 SGR 418Water and Soil Quality Unit, IDAEA-CSIC)