Trace metal distribution in pelagic fish species from the north-west African coast (Morocco)

Imane Afandi,Sophia Talba,Luis Tito De Morais,Ali Benhra,Raymond Laë,Samir Benbrahim,Rachid Chfiri,Fatima Zohra Bouthir,Hicham Masski,Maylis Labonne,Mohammed Bekkali

doi:10.1007/s40071-018-0192-7

Abstract

In the current study, ten elements contents (Fe, Zn, Mn, Cu, Cr, Co, Ni, Cd, Pb and Hg) have been measured in muscle and liver of four pelagic fish species (Engraulis encrasicolus, Sardina pilchardus, Scomber japonicus and Trachurus trachurus) from the north-west African coast (South Atlantic Moroccan coast), collected during summer and autumn seasons (July and December 2013, respectively). Significant differences in metal contents were found between the different species (p < 0.05). Metals levels were also much higher in liver than those recorded in muscle tissues. The concentrations of Fe, Zn, Cd, Co, Cu and Pb were significantly higher in mackerel liver (p < 0.05).While, in muscle, anchovy presents a higher content of Mn, Cu, Cr, Ni and Pb. A high level of cadmium was recorded in liver of the different species which can be attributed to an anthropogenic source (phosphate industry) and to natural sources (upwelling activities). The main concentration of toxic elements (Cd, Pb and Hg) recorded in the four edible muscles of pelagic fish species, under study, were below the established values by the European Commission Regulations and show that their effect on the consumers health can be considered as negligible.

Highlights

The metal pollution of the marine ecosystem has always been admitted as a serious environmental issue (Blakas et al 1982; Tariq et al 1991)
The concentration of ten metals elements measured in liver and muscle tissues are reported for each species in Tables 2 and 3
The investigation of trace metal contamination levels in fish from the southern Atlantic Moroccan coast showed the presence of differences of contamination between species and considered organs, as well as Concentrations μg.g-1d.w

Summary

Introduction

The metal pollution of the marine ecosystem has always been admitted as a serious environmental issue (Blakas et al 1982; Tariq et al 1991). Four pelagic fish species including (Engraulis encrasicolus (anchovy), Sardina pilchardus (sardine), trachurus trachurus (horse mackerel) and Scomber japonicus (mackerel)) were selected These fish species are of particular importance due to their intermediate position in the food web and for their abundance. Mackerel has a cosmopolitan distribution including warm and temperate waters of the Atlantic, Indian and Pacific Oceans and adjacent seas It is essentially a near coastal species, with a vertical distribution ranging between 0 and 300 m of depths. The purpose of this work (involved in the framework of EPURE project research program) is to determine and compare the concentrations of Zn, Fe, Cu, Pb, Cd, Cr, Co and Hg in the liver and muscle of four small pelagic fish species from the south Atlantic Moroccan coast during two periods of upwelling phenomena, in July season of strong upwelling and December season of weak upwelling. The objective is to describe the differences of the concentrations of trace metals between species, between upwelling seasons and to compare the results with guidelines set down by the European Commission Regulation (European Commission Regulation (EC) 2008, 2014, 2015) for the safe consumption limits of fish and the other studies

Materials and methods

Results

Discussion