An Assessment of the Total and Methyl Mercury Content of Zooplankton and Fish Tissue Collected from Kuwait Territorial Waters

Abstract

The results of a study of total-Hg (T-Hg) and MeHg concentrations in zooplankton and various fish species collected from Kuwait Bay and the northern area of Kuwait are reported. T-Hg concentrations in zooplankton ranged from 0.004 – 0.035 μg g −1 (dry weight) with MeHg representing <25% of the T-Hg. Total and MeHg concentrations in fish differed between species and ranged from 0.073 μg g −1 ( Liza subviridis) to 3.923 μg g −1 ( Epinephelus coiodes). T-Hg and MeHg in fish tissue were significantly correlated at 0.01 level. They were also correlated with length and weight of the analysed species. The mean percentage of MeHg ranged from 40.1% ( Hilsha ilisha) to 80% ( Epinephelus coiodes) of the T-Hg. The relationships between observed concentration, habitat and feeding habits are examined. Of the fish analysed 20.6% were ⩾0.500 μg g −1 T-Hg, and exceeded the WHO limit. For MeHg, 20.6% were ⩾0.300 μg g −1. It is estimated that ∼3.2 kg of Hg and ∼1.9 kg of MeHg are being removed yearly by fish landings from Kuwait territorial waters and introduced to the local food supply.