Heavy Metals in Organs and Tissues of the European Black Vulture (Aegypius monachus): Dependence on Living Conditions

The distribution of Fe, Zn, Cu, Cd, Mn, Pb, and Ni in the organs and tissues (kidneys, liver, lungs, brain, heart, muscles, and feathers) of the European black vulture (Aegypius monachus) was studied. It was shown that heavy metals were not responsible for the mass mortality of these birds in southern Primorye in the winter of 2001–2002. The level of pollution with heavy metals of the range of European black vultures wintering in this region (northern China and western Mongolia) may be regarded as insignificant.     

Metal concentrations in mussel Crenomytilus grayanus and oyster Crassostrea gigas in relation to contamination of ambient sediments

The relationship between Zn, Cu, Cd, Pb, and Ni concentrations in soft tissues of mussels and oysters and those in ambient sediments was examined. The study area was the coastal habitats of the northwestern Sea of Japan, which has a broad range of contamination due to urban sewage. Significant increases of all metals, except Ni, were observed in mussel Crenomytilus grayanus at concentrations of easily leachable metals in ambient sediments higher than 2, 100, and 800 microg/g for Cd, Cu, and Zn, respectively. Pb was accumulated by the mussels with no distinct threshold in Pb contamination of sediments. After 2 months, C. grayanus transplanted from a pristine to a contaminated locality increased in Pb up to 12%, and Cu up to 68% of concentrations of these metals in the contaminated local mussels, but Zn and Cd concentrations increased only in the excretory tissue, not in the somatic tissue, or in the soft tissue as a whole. Such regulation of metal accumulation puts limitations on the use of C. grayanus for monitoring of slightly and moderately contaminated localities. On the other hand, the oyster Crassostrea gigas showed definite accumulation of all metals, except Ni, at moderate contamination of ambient sediments. As contamination of sediments increased, increases of Pb, Zn and Cu concentrations in C. gigas slowed, possibly due to physiological control at very high metal concentrations in oyster soft tissue. Thus, the mussel C. grayanus should be used mainly for the monitoring of heavy contaminated localities, and the oyster C. gigas is more suitable as an indicator of low and moderate contamination.