Long-term response of an arctic fiord system to lead-zinc mining and submarine disposal of mine waste (Maarmorilik, West Greenland)

International audience; Contamination by lead (Pb) and zinc (Zn) was studied in seawater, sediment, seaweed and blue mussels near the former "Black Angel Pb-Zn Mine" in Maarmorilik, West Greenland. The mine was operated during the period 1973-90 when mine waste (tailings and later waste rock) was discharged directly into the sea. Metal concentrations peaked during the mining period and Pb and Zn in seawater within the discharge area were measured up to 440 and 791 μg L, respectively. Pb concentrations in sediment, seaweed and mussels just outside the discharge area were measured up to 187, 84 and 2,650 and Zn up to 655, 363 and 1,190 μg g dry wt., respectively. Within the discharge area, seawater metal concentrations (especially Pb) decreased abruptly after mine closure. Metals concentrations in sediment and biota, however, decrease more slowly and two decades after mine closure seaweed and blue mussels are still contaminated 12 km from the mine.