Methylmercury and total mercury content in soft tissues of two bird species wintering in the Baltic Sea near Gdansk, Poland.

Of the various forms of Hg occurring in nature, (mono) methylmercury (MeHg) is an especially toxic form and practically all forms of Hg can be converted into MeHg as a result of natural processes. Total mercury (THg) and MeHg were determined in tissues of two piscivorous birds: razorbill Alca torda and black-throated loon Gavia arctica to provide baseline data on current mercury concentrations for liver, kidneys and pectoral muscle mercury concentrations of birds which winter on the south Baltic Sea coast. Intra and inter-specific comparisons were carried out. The study is conducted between winter and autumn and the distributions of mercury in tissues were compared with data in other studies. The following paper contains discussion of the results based on the statistical analysis and ecology aspect. The highest average Hg content was in the liver (loon ≈ 3.86 mg kg-1 dw; razorbill ≈ 1.57 mg kg-1 dw), then in the kidneys (loon ≈ 3.14 mg kg-1 dw; razorbill ≈ 1.53 mg kg-1 dw) and the lowest concentrations were in pectoral muscles (loon ≈ 1.97 mg kg-1 dw; razorbill ≈ 0.67 mg kg-1 dw).