Résumé:
This work focuses on the structure and diversity of benthic macroinvertebrates in the
national parc of chréa. Benthic macroinvertebrates were sampled according to the Standard
Global Biological Index (IBGN) protocol at three (03) stations (0ued el mardja , 0ued el
hamdania ,Oued chiffa ). The structure of benthic communities has been studied using
Shannon and Piélou indices. A Canonical Correspondence Analysis (CCA) was conducted to
characterize the macroinvertebrate community. The results show that the macroinvertebrates
harvested (1345 individuals) belong to 41 families and 14 order. This macrofauna consists
insects, worms and molluscs. The families of Diptera and Ephéméroptera are the most
frequent and the most abundant on all stations. The values of the Shannon and Piélou indices
obtained were low. The distribution of macroinvertebrates was strongly influenced by altitude
and depth. The preponderance of the three families of polluo-resistant macroinvertebrates
(chironomidae, ceratopogonidae and lumbriculidae) reveals indicates the poor water quality of
the water in the three stations. Similarly, the indices of diversity and equitability indicate that
the macroinvertebrate community of our stations are very unbalanced. These results lay the
foundation for any biomonitoring action of the ecological water quality of those valleys
