High mercury concentrations in Atlantic Goliath Grouper: Spatial analysis of a vulnerable species.

The Atlantic Goliath Grouper Epinephelus itajara is currently a protected species in the southeastern United States waters of the Atlantic and the Gulf of Mexico and is considered vulnerable throughout its geographic range. In this study, I evaluated mercury concentrations in their tissues (muscle, liver), which revealed high concentrations (μg/g ww) of mercury (mean ± SE) in liver (6.18 ± 0.86) and muscle (1.12 ± 0.06) tissue that increased with size and age. Mercury concentrations were highest in fish caught off Florida's Atlantic coast, but varied on a finer regional scale. Mercury concentrations in muscle tissue were generally greater near urbanized areas with known mercury sources and environmental conditions appropriate for higher methylation rates. This suggests that management should consider improving the water quality in these areas to reduce the risk of health effects to human consumers and to the fish themselves. • Mercury concentrations were the highest reported for any regional grouper species. • Differences occurred in mercury concentrations within and between Florida ocean basins. • %Methyl mercury increased with age in muscle tissue and decreased in the liver. • Nearly all mercury concentrations exceeded federal recommendations for consumption. • High liver-to-muscle mercury relationships indicate heightened mercury exposure. [ABSTRACT FROM AUTHOR]