Mercury Contamination of the EEL (Anguilla Anguilla) and Roach (Rutilus Rutilus) in East Anglia, UK

The muscle tissue total mercury (THg) and organomercury (OrHg) concentrations of eel (Anguilla anguilla) and roach (Rutilus rutilis) from the Hg-contaminated River Yare and the uncontaminated Ormesby Broad were compared to their respective bed sediment THg and OrHg concentrations in order to determine if fish in the River Yare had begun to approach 'background' levels. While eel from the Yare had higher flesh concentrations (260 g kg-1) than those from Ormesby Broad (102 g kg- 1), roach were found to have similar concentrations regardless of location (55 and 54 g kg-1 for Yare and Ormesby respectively). However, roach in the Yare had significantly higher body burdens of Hg and organomercury, which when analysed over time (1985–95) showed a decreasing trend approaching the levels observed in fish from Ormesby Broad, suggesting that roach are an overall better biomonitor of contamination then eel. This said, the elevated levels of Hg found in fish from Ormesby Broad indicate the existence of a diffuse source such as atmospheric deposition to the surface waters of East Anglia.