Diversity of aquatic macroinvertebrates and water quality of the High Andean wetlands of Chalhuanca, Arequipa-Peru

Abstract

Water quality is an issue of global concern because of the evident contamination of the sources of this resource. In recent decades the study of inland waters has been oriented towards the recovery and conservation of these ecosystems, in this sense abundant studies were carried out in lotic systems, and to a lesser extent in lentic systems and in a much more reduced way in high Andean wetlands. This work represents one of the few carried out in high Andean ecosystems , and lentic such as are the Chalhuanca bofedales. The high Andean wetlands of Chal-huanca provide important ecosystem services, among which stand out the water regulation, water reservoirs, and endemic species habitats. The aim was to assess water quality in the high Andean wetlands of Chalhuanca (Arequipa) using macroinvertebrate bioindicators. Samples were taken during the wet season (January) and dry season (June) in 2018; 2 sampling methods were used, Surber net for river and D-frame net for bofedal. Individuals were identified until genus in most cases through taxonomic guides. Biotic quality was determined using the BWMP/Bol, ABI and nPeBMWP indexes; physicochemical parameters were also evaluated in each study site. We found 6 phylum, 10 classes, 18 orders, 26 families and 33 taxa. According to biotic index, sampling sites presented water quality from critical or bad to acceptable. The physicochemical parameters were found in the range set by the ECAs of D.S.004-2017 MINAM, except the dissolved oxygen, which in the most study sites was lower than the established for water intended for conservation of the aquatic environment. Regarding diversity, it was found that it was greater in the dry season both in the river and in the bofedal, however, the abundance varied, finding greater abundance in bofedales in the wet season and greater abundance in the river in the dry season. The high Andean wetlands of Chalhuanca present a limited diversity of macroinvertebrates families and a regular water quality in most sampling sites.