Biomagnification of methylmercury in a marine food web in Laizhou Bay (North China) and associated potential risks to public health.

The concentrations of total mercury (THg) and methylmercury (MeHg) were assessed in water, sediment and biota (54 species) samples from the coast of Laizhou Bay, to evaluate MeHg biomagnification in Laizhou Bay food web. The trophic web structure was determined with stable isotope ratios. The MeHg concentrations were highly variable among species ranged from 4.8 ng g-1 in primary producers to 411.2 ng g-1 in spotted sea bass. Weight and ecotype were the principal parameters related to the mercury concentrations for most species. The trophic magnification factors (TMFs) for MeHg and THg were 2.09 and 1.69, respectively, indicating that mercury biomagnification is occurring in this marine food web. The estimated weekly intake (EWI) and target hazard quotient (THQ) values demonstrated that consuming predatory fishes from the bay could cause potential health risks to humans.