Heavy metals and other elements in three tissues of cod, Gadus morhua from the Northwest Atlantic

Abstract

Over twenty elements were analysed in the muscle, liver and ovaries of cod, ( Gadus morhua) collected in Norwest Atlantic Fisheries Organization (NAFO) Divisions 2J and 3Ps off the coast of Newfoundland. Many of the elements are being reported for the first time for marine fish in general and cod in particular. Kendall rank correlations existed between the concentrations of 16 elements (Ag, As, Ca, Cd, Co, Cs, Cu, Fe, Mg, Mn, Mo, Ni, Rb, Se, Sr, and Zn) in liver and ovary and liver and ovary size. This relationship was most pronounced for Mn in muscle. Concentrations of priority heavy metals (Hg, Cd, and Pb) in muscle and liver were similar or lower than levels reported in cod from the NE Atlantic, the North Sea and the Baltic Sea. They were also similar to concentrations reported in cod from NAFO Divisions 3M, 4X, 4T, and 4Vn. Overall, concentrations of the priority heavy metals Hg, Cd, and Pb were well below levels permissible in food products. Of all the elements investigated in this study, Hg was elevated in muscle, Ag in liver, and Zn and Se in ovaries. One of the most novel observations in this study with cod was the distinct differences in boron and aluminum levels between the two stocks of fish, boron being elevated 28 fold in the muscle of fish from Division 2J. The source and nature of boron in fish muscle warrants further study.