Structure of benthic communities (macroinvertebrates and diatoms) in the lower stretch of a Mediterranean larger river.

Resumo

The Ebro River, located in the NE of the Iberian Peninsula (Fig. 1), is the largest Mediterranean river in Spain. With a basin surface of 85 550 km2, it is the Spanish river with the highest mean annual flow and one of the most important tributaries to the Mediterranean Sea. (Sierra et al., 2004; Ibánez et al., 2008; Prats et al., 2010; Ibáñez et al., 2012). The lower part showed a characteristic pattern of anthropogenic alterations (flow regulation and water pollution) present in large Mediterranean rivers.

The aim of this study was to examine benthic communities with regard to species composition, community structure and distribution patterns along spatial and temporal scales and to describe the main abiotic factors affecting communities of macroinvertebrates and diatoms. The study area cover all the lower Ebro river morphological variability.