ANALYSIS OF SEAWATER QUALITY ON THE ORAN COAST USING PHYSICO-CHEMICAL PARAMETERS AND TRACE METALS (FE, MN, NI) AND THEIR IMPACT ON CHELON LABROSUS (RISSO, 1827) FISH

The Oran coastline in Algeria is a region particularly affected by human activities. This area faces significant environmental concerns in the Mediterranean due to the pressures exerted by urban, industrial, agricultural, and port traffic discharges. Therefore, it is essential to conduct a water quality assessment based on physico-chemical parameters and the measurement of certain trace metals in order to understand their impact on Chelon labrosus a species highly valued by the local population. This research is part of an environmental monitoring mission aimed at studying parameters to detect and assess pollution levels in water and in Chelon labrosus. The aim of the study is to spatially evaluate the physico-chemical parameters and the concentration of trace metal elements in the water of the Oran coast, as well as the levels of these elements in the various organs of Thick-lipped grey mullet. The results of water quality assessment in the Oran coast have revealed that the general trend in the levels of the parameters analysed shows a deterioration. These results indicate a slight risk, as some parameters exceed international seawater quality standards. Analyses of trace metal elements reveal the presence of these pollutants both in the water taken from the sampling site and in the fish species caught. The highest concentration in seawater was observed for nickel, followed by manganese and finally iron, with values of 0.74 mg/l, 0.56 mg/l and 0.47 mg/l respectively. Compared with the concentration of iron, manganese and nickel found in the water sampled at the sampling site, the levels of these elements in the Chelon labrosus are significantly higher, at 1.94 mg/kg, 1.71 mg/kg and 1.09 mg/kg respectively.