Abhatoo - Centre Nationale de Documentation

Benthic macroinvertebrates of the Afenourirlake were studied from samples collected between June 2015 and June2016 ; the results of the benthic fauna identified in this study consist of 4945 individuals representing 17 families belonging to 4 faunistic groups : (arthropods (79%), annelids (15%), mollusks (5%), and Nemathelminthes (1%)). The number of benthic population showed a dominance of the crustaceans (44%) and, Diptera (Chironomidae larvae (32%)) followed by, Oligochaeta (9%), the Achaetes (6%), and gastropods (6%). whereas the Odonata (1%), Heteroptera (1%), Ephemeroptera (1%) and Coleoptera (0%) are only a small fraction of the total fauna. A comparison is made between pollu-tolerant and pollu-sensitive taxa in order to assess the quality of the water of the lake and the degree of degradation of the wetland. This comparison shows that at the level of 4 stations (upstream and downstream), there is a poor water quality due to a high proportion of pollu-tolerant taxa (ChironomidaeSp, and annelids). The results obtained in this study show a critical situation of water
quality at the Afenourirlake and this may cause a degradation of the wetland. To address this problem, it is necessary to carry out a proper planning and management of human activities practiced at Afenourir.