Work

Application of biotic indices to determine the ecological status of Oued El Abid Basin, Azilal, Morocco

Year: 2025

Type: article

Abstract: Morocco is one of the countries the most affected by water shortages, and the Beni Mellal-Khenifra region is not an exception, specifically The Oued El Abid basin. The study was carried out over an annual cycle at 7 stations. Biotic indices including the Normalized Global Biological Index (IBGN), the River Habitat Quality Index (HQI), and the Riparian Quality Index (RQI) were used for the ecological diagnosis. The surface water quality was assessed by analyzing 15 physicochemical parameters (temperature, pH, DO, EC, COD, NO 3– , Cl - , SO 4 2- , PO 4 3- , TH, Fe 2+ , Cu 2+ , Pb, Cr, Cd). Current results indicate a notable degradation in water quality downstream of Oued El Abid, at S7, with high values for COD (42.01 mg L -1 ), EC (1538 µS cm −1 ), and Cl - reaching 205.9 mg L -1 , and upstream of Oued Ahansal (S2) with DO (3.02 mg L -1 ) and COD (36 mg L -1 ) values, which classify this stream as poor to average, linked to domestic and agricultural pollution. Metals analyzed reveal a total or partial absence in places. The values of the three biotic indices classify the water at the various stations studied as being of critical quality for stations S2 and S7, of average quality for S3, S4, and S6, and of average to good quality for S1 and S5. PCA revealed that the three biotic indices shows a high negative correlation with EC and a strong positive correlation with DO. This suggests that less conductive and better-oxygenated waters are associated with better biological quality. Distance-based linear models (DistLM) show that several environmental variables significantly influence the variation of biological or ecological parameters of Oued El Abid aquatic ecosystem.

Source: The Egyptian Journal of Aquatic Research

DOI: 10.1016/j.ejar.2025.09.003

Authors: El-hissoufi Abdelhamid, El Bouqdaoui Karima, Selfati Mohamed, Fahde Abdelilah, Zaroual Zaina, Ait Benichou Samah

Institutions: University of Hassan II Casablanca, Institut Supérieur des Professions Infirmières et Techniques de Santé de Casablanca

Language: English

Topic: Water Quality and Pollution Assessment

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDG: Clean water and sanitation

Open Access status: gold

Estimated APC paid: $1,200