Impact of the longitudinal and seasonal changes of the water quality on the benthic macroinvertebrate assemblages of the Andorran streams.
The ecological quality of the Andorran streams was assessed in 1998-1999, based on the survey of the water chemistry and the benthic macroinvertebrate assemblages. Two types of modification of the water quality were observed in the Andorran rivers: (i) a progressive degradation along the longitudinal gradient with a chronic degradation in the lower water courses; (ii) a seasonal modification in the mid-elevation sites. Two responses of the benthic macroinvertebrate assemblages to these disturbances were observed: an extreme simplification of the composition and a change of the trophic structure of the assemblages in the more impacted sites.
Younes-Baraillé
Yasmina
Y
Laboratoire Dynamique de la Biodiversité, UMR 5172, bât. 4 R3, b1, Université Paul-Sabatier, 118, Route de Narbonne, 31062 Toulouse cedex 4, France. younes@cict.fr
Garcia
Xavier-François
XF
Gagneur
James
J
D000725:Andorra; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005618:Fresh Water; D006863:Hydrogen-Ion Concentration; D007448:Invertebrates / Q000145:classification / Q000502:physiology*; D010100:Oxygen / Q000032:analysis; D012621:Seasons; D013696:Temperature; D014195:Travel; D014873:Water Pollutants / Q000032:analysis; D014876:Water Pollution / Q000009:adverse effects*
D014873:Water Pollutants; D010100:Oxygen