O. T. Moldovan, E. Levei, C. Marin, M. Banciu, H. L. Banciu, C. Pavelescu, T. Brad, M. Cîmpean, I. Meleg, S. Iepure, I. Povara, Spatial distribution patterns of the hyporheic invertebrate communities in a polluted river in Romania, Hydrobiologia, , 669 (2011) 63-82.

Title: Spatial distribution patterns of the hyporheic invertebrate communities in a polluted river inRomania

Abstract: The purpose of this study was to examine the sensitivity, in a field situation, of the hyporheic fauna to pollution by heavy metals and also to test the use of oxidative stress enzymes produced by this fauna as a sensitive indicator of oxidative stress generated by chemical contamination. This was done by surveying the patterns of distribution, structure, and composition of hyporheic invertebrate communities in one of the most polluted rivers in Romania. Twelve permanent sampling stations with differing water qualities were established along a 180 km transect of the Aries¸ River. Data on hyporheic invertebrate abundance and richness,chemistry of the surface and hyporheic water and interstitial suspended particles were analyzed via multifactorial analyses. In the downstream, more polluted stations, epigean species were less abundant and hyporheic communities, especially macrocrustaceans and oligochetes, became dominant. The higher levels of hyporheic invertebrate biodiversity in the moderately polluted stations compared to highly polluted, and the increase of the number of some hyporheos (especially macrocrustaceans) in the moderately polluted stations,suggested that the hyporheic fauna wasmore tolerant of heavymetal pollution than the surfacewater fauna of the area. However, the different richness and abundance of hyporheic fauna in sites of similar water chemistry suggested that additional factors, such as sediment structure are shaping the spatial distribution of hyporheic fauna. Strong correlations between superoxide dismutase (SOD) activity in pooled tissues extracts andsome chemical parameters suggest that oxidative stress enzymes may prove to be sensitive indicators of chemical pollution in hyporheic zones.

Keywords: Interstitial fauna, Crustacea, Heavy