LEVELS OF MERCURY IN THREE SPECIES OF TUNA (KA TSUWONUS PELAMIS, A UXIS THAZARD AND EUTHYNNUS AFFINIS) COLLECTED FROM THE JORDANIAN COAST OF THE GULF OF AQABA, RED SEA

Level of mercury (Hg) heavy metal concentrations were investigated using Direct Mercury Analyzer (DMA) in muscles, liver, gills, gonads and kidney of three fish species (Katsuwonus pelamis, Auxis thazard and Euthynnus affinis) that were collected from the Jordanian coast of the Gulf of Aqaba, Red Sea during May to December 2015. Heavy metals accumulation varied significantly between organs, generally, the highest Hg concentrations were found in muscles of K. pelamis, A. thazard and E. affinis with an average 0.500, 0.354 and 0.244 µg/g respectively and the lowest concentrations were found in gills of K. pelamis with an average 0.113 µg/g and gonads of A. thazard and E.affinis with an average 0.140 µg/g and 0.110 µg/g respectively. The accumulation of heavy metals concentrations in the muscles than other organs is an indicator for clean, pollution-free environment. Strong positive correlations have been found between fish length and Hg concentrations. Levels of Hg in tuna fish muscles were within the acceptable limits for human consumption.