Total mercury content, weight and length relationship in swordfish (Xiphias gladius) in Sri Lanka

Mercury (Hg) is a global environmental pollutant that has been the cause of many public health concerns. It is transferred through trophic level and bio magnification in the food chain. Total Hg level was measured by cold vapour atomic absorption spectrometry in muscle tissue of 176 Swordfish (Xiphiasgladius) samples ranging from 11.8-112.0 kg total weight and 45-278 cm total length, collected from major fish landing sites in Sri Lanka during July 2009 to March 2010. Total Hg concentration varied between 0.18-2.58 mg/kg wet weight (ww), with a mean value ± standard deviation of 0.90 ± 0.52 mg/kg ww. Of the investigated samples 32% exceeded Hg limits as set by the European Union and Sri Lankan legislation (1 mg/kg, ww). Hg concentration of swordfish showed a significant positive relationship (P value < 0.05) with the fish length and weight. Consequently, consumption of larger fish leads to an increase in the exposure level for consumers.