Residues of total mercury in fish from two small lakes in the biosphere reserve of Schorfheide‐Chorin in Brandenburg, east Germany

Abstract

Total mercury was determined in white trunk muscle of fish from two small lakes using flameless AAS. Both lakes, surrounded by forest and agricultural fields, are situated in the biosphere reserve of Schorfheide-Chorin about 50 km northeast of Berlin. Direct contamination by sewage and industrial waste has been excluded definitively. In the Plunzsee (area 25 ha, depth 10 m, no surface inflow, temporary outflow), 9 of 10 northern pike (Esox lucius) had mean Hg contents of 0.590 mg kg−1 (range 0.509–0.674) and therefore residues distinctly above the “normal level” of 0.2 mg kg−1, which is taken by the World Health Organization (WHO) to characterize fish from uncontaminated inland waters. Four of five roach (Rutilus rutilus) had Hg residues (0.272–0.393 mg kg−1) above the WHO limit, but 4 of 5 bighead carp (Aristichthys nobilis), a stocked filter-feeder, ranged beneath it. In the Dollnsee (22 ha, 8 m) Hg residues in 28 pike ranged from 0.027 to 0.378 mg kg−1 with a mean of 0.154 mg kg−1. In 10 bream (Abramis brama), these data were 0.016–0.072 mg kg−1 and 0.050 mg kg−1, respectively. Twenty-one roach had mean Hg contents of 0.088 mg kg−1 (range 0.038–0.182). In 8 perch (Perca fluviatilis) and 12 eel (Anguilla anguilla), these data were 0.063 mg kg−1 (0.051–0.090) and 0.073 mg kg−1 (0.008–0.170), respectively. None of the 99 muscle samples exceeded the hygienic mercury limits of the Federal Republic of Germany. A possible Hg load by airborne wet and dry depositions is discussed. © 1994 by John Wiley & Sons, Inc..