Document Type : Original Research Paper
Authors
1
Department of Biotechnology, Bioresources and Bioinformatics, Khenifra Higher School of Technology Sultane Moulay Slimane University, Khenifra , Morocco
2
Department of Biotechnology, Bio-resources and Bioinformatics, Khénifra Higher School of Technology; Sultane Moulay Slimane University, Morocco.
3
Laboratory of multidisciplinary research in science, technology and society, Khenifra Higher School of Technology; Sultane Moulay Slimane University, Morocco.
4
Laboratory Biology and Health, Department of Life Sciences, Faculty of Sciences, Kenitra, Ibn Tofail University, Morocco.
5
Laboratory of "Scientific Research and Educational Innovation", Regional Center for Education and Training Professions, (CRMEF Rabat-Salé-Kénitra), Morocco.
10.22059/poll.2026.405316.3185
Abstract
The Oum Er Rbia River is an ecosystem that is essential for biodiversity and human activities, but it is threatened by the degradation of its aquatic habitats, particularly due to the discharge of domestic wastewater. The assessment of water quality, carried out using physicochemical and biological approaches, shows significant variations between sampling stations. Stations S1 and S2 exhibited optimal physico-chemical characteristics for biodiversity, complying with water quality standards (e.g., BOD₅ below 3 mg/L). This was reflected in the biotic communities, which showed high taxonomic diversity and a dominance of highly sensitive groups such as Ephemeroptera and Plecoptera. In contrast, station S3 has very poor water quality, with BOD₅ of 48 mg O₂/L and COD of 239 mg/L, as well as Dissolved Oxygen (DO) to 5 mg/L. The IBGN is very low 5 < IBGN < 8, with a dominance of polluent-tolerant taxa, such as Chironomidae, reflecting a significant loss of biodiversity. At the downstream station S4, BOD₅ decreases to 11 mg O₂/L and COD to 38 mg/L. The IBGN reaches 13 and the OPI is 3.25, indicating moderate pollution. Statistical analysis confirmed that organic pollution is the principal driver of water quality degradation and biological impairment along the river, with principal component analysis (PCA) clearly demonstrating the strong relationship between organic load, physicochemical parameters, and macroinvertebrate community structure. This study provides crucial information to guide conservation and restoration efforts for the Oum Er Rabia ecosystem.
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