ASSOCIATION OF TOTAL MERCURY AND CADMIUM CONTENT WITH CAPTURE LOCATION AND FISH SIZE OF SWORDFISH (Xiphias gladius); INDIAN OCEAN

Abstract

Mercury (Hg) and cadmium (Cd) are non-essential trace elements that transfer through the trophic chain which ultimately bio-accumulate and biomagnify in the upper trophic level . The total Hg (THg) and Cd levels of the muscle tissues of swordfish, Xiphias gladius caught in three different areas in the Indian Ocean around Sri Lanka were determined. THg and Cd levels were <0.07-4.30 mg/kg and <0.006-0.180 mg/kg, (wet weight basis) respectively. Of the analyzed samples, 13.3% fish were over 1 mg/kg for THg while not any single sample exceeded 0.30 mg/kg for Cd which is EU, and FDA action limits. The results indicate that the catching locations do not govern the THg and Cd levels and it showed a weak positive relationship between the length and weight of the fish.