Characterization of organochlorine pesticides in the surface waters of Marchica Lagoon, Morocco

Abstract

The main objective of this initial study is to assess the extent of surface water contamination in Marchica Lagoon caused by organochlorine pesticides (OCPs) historically used in agriculture through a sampling network consisting of eight stations covering all areas of the lagoon during the 2022 summer season. Located on Morocco’s Mediterranean coast, the lagoon has undergone several restoration actions since 2010 to improve its environmental state. However, this ecosystem is under constant pressure from its watershed, which can convey water pollution from agricultural, industrial, mining, and domestic sources, making continuous monitoring essential. Eight organochlorine pesticides (Alpha HCH, Beta HCH, Gamma HCH, Aldrin, Dieldrin, DDD, DDE, and DDT) were detected by gas chromatography-mass spectrometry (GC-MS) using the SIM (Selected Ion Monitoring) method. The results revealed OCPs contamination of the lagoon’s surface waters; the spatial variation of total OCPs concentrations (Σ8OCPs) ranged from 7.58 to 18.79 ng/l. The predominant element detected was β-HCH (lindane), recorded between the Bouarg channel and Selouane wadi, an area characterized by intensive agriculture.