Freshwaters are among the most threatened ecosystems, particularly in North Africa where urbanization and climate change are exerting an important pressure on aquatic fauna. Long-term investigation of macroinvertebrates is one of the best ways of tracking and understanding the influence of environmental and anthropogenic pressures on community dynamics. In this study, we focus on determining the community structure and diversity of benthic macroinvertebrates as well as the state of aquatic physicochemical parameters in the Bouhamdane Stream, near the outlet of Bouhamdane dam, Seybouse watershed, north-eastern Algeria. We carried out a bi-monthly sampling of macroinvertebrates and nine water physicochemical parameters from September 2017 to July 2018 at three sites. Results show that the collected macroinvertebrates (6756 individuals) belong to 15 families and 12 orders. The abundance of the macrofauna consisted of 88.19% crustaceans, 7.74% insects, 3.7% molluscs and 0.16% annelids. Physicochemical analyzes (depth, turbidity, pH, dissolved O2, temperature, salinity, and conductivity) showed variability among sites. The families of Gammaridae and Baetidae were the most frequent and the most abundant on all the stations. The results indicate that aquatic macroinvertebrates constitute good indicators of the biological quality of water. This study shows that even with the occurrence of regular dam water discharge, the macroinvertebrate community is still able to persist either through adaptation to high water velocity or high colonization rate.
Different hydro climatic conditions at and above a continental shelf have significant effects on the ecology of the environment (temperature, nutrient richness and pelagic production). Indeed, bioclimatic changes defined clearly reflects the prevailing conditions imposed above the continental shelf. Based on contributions made to the sea (rainfall, temperature, wind ...) and those put together by the internal dynamics can be distinguished marine years that correspond to low enrichment in terms of any change in continental and marine conditions generally short and strong enrichment of years corresponding to eventful years and transformations of continental and marine conditions, strong shifts in time. Thus, a hot or cold but very fluctuating period influence the marine ecosystem and phytoplankton growth. Also, the impact of development on the coastal and marine environment is localized mainly in the coastal metropolitan areas characterized by high urbanization and concentration of activities. Keywords: climate change; environmental variability; Ecosystem vulnerability; West coast of Algeria. Résumé Les différentes conditions hydro climatiques qui règnent sur et au-dessus d'un plateau continental ont de considérables effets sur l'écologie du milieu (température, richesse nutritive et production pélagique). En effet, l'évolution bioclimatique définie, reflète nettement les conditions dominantes imposées au-dessus du plateau continental. En fonction des apports apportés à la mer
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