Chironomidae (Diptera) diversity in extreme environments (Salar de Olaroz, Puna Desert, Argentina)

The Salar de Olaroz, located in the Argentine Puna, is one of the largest lithium deposits of the world. Lithium extraction requires large amounts of fresh and brackish water, creating pressure on wetlands of these desert environments. The knowledge of the aquatic fauna of the area is of interest to monitor impacts of these extractive activities. In this work, a study of the Chironomidae (Diptera) prior to mining is carried out in order to understand the structure of the Chironomidae assemblage at morphospecies level, with the aim of evaluating its spatial and seasonal variation, relating changes in the assemblage to some environmental variables. Quantitative biological samples and environmental variables of interest were taken and registered in three streams during four season in three consecutive years (2013-2015). Our results show that the Chironomidae assemblage could respond to variables related with discharge by decreasing its richness. Some morphotypes (e.g., Podonomus, Parametriocnemus, Limnophyes and Polypedilum) associated with changes in pH, decreases in dissolved oxygen and water velocity, and increases of finer sediments could disappear from the area.