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Mercury (Hg) is a naturally occurring metal in the earth's crust and can enter the aquatic environment through natural
and anthropogenic activities. Part o f Hg is converted to methyl-mercury (MeHg) and accumulates in fish through the food chain
reaching its highest levels in large predatory fish such as tuna. Consumption of contaminated fish has been considered a serious
public health concern. Yellow fin tuna ( Thunnus albacares, YFT) comprises the most important component o f the Indian Ocean
tuna catches and it can contain significant levels o f MeHg. For better understanding and monitoring purpose of Hg levels in YFT
populations, total Hg (T-Hg) concentrations were analyzed in edible muscle tissue from 140 YFT collected from major fish
landing sites o f Sri Lanka in 2010 and 2011. The samples were analyzed using cold vapour atomic absorption spectrophotometric
method, with microwave assisted digestion. In Sri Lankan waters, Hg levels in YFT ranged from <LOD (0.021) to 0.98 mg/kg
(mean ± SD = 0.30±0.18 mg/kg; median = 0.27 mg/kg) in wet weight basis. Data from the present study suggest that Sri Lankan
YFT contain lower levels o f Hg compared with the EU/EC recommendations (1 mg/kg). T-Hg levels of YFT were positively
related with fish length and weight.
