Biomagnification of mercury through the benthic food webs of a temperate estuary: Masan Bay, Korea.

The authors examined food web magnification factors of total mercury (THg) and methylmercury (MeHg) for the benthic organisms in Masan Bay, a semiclosed, temperate estuary located on the southeastern coast of Korea. For benthic invertebrates, concentrations of THg and MeHg (%MeHg) ranged from 9.57 to 195 and 2.56 to 111 ng/g dry weight (12.2-85.6%), respectively. Benthic fish THg and MeHg (%MeHg) concentrations ranged widely from 10.8 to 618 and 2.90 to 529 ng/g dry weight (22.9-93.9%), respectively. The linear regression slopes of log [Hg] relative to δ(15)N (i.e., food web magnification factors) found for the Masan Bay benthic organisms were 0.119 for THg and 0.168 for MeHg. These values are similar to the food web magnification factors of benthic organisms and lower than those of pelagic organisms of various coastal marine environments. It suggests that pelagic organisms might be at greater risk of THg and MeHg accumulation than benthic biota.