ABSTRACT
We used a comparative approach to investigate the impact of the disposal of gold mine tailings into the ocean near the Lihir mine (Niolam Island, Papua New Guinea). We found abundance and diversity of zooplankton, micronekton and pelagic fish to be similar or higher in the mine region compared to the reference site. We also found relatively high trace metal concentrations in lower trophic level groups, especially zooplankton, near the mine discharge, but few differences in tissue concentrations of micronekton, baitfish and pelagic fish between the two regions. Biomagnification of some trace metals by micronekton, and of mercury by fish was evident in both regions. We conclude that ocean mine waste disposal at Niolam Island has a local impact on the smaller and less mobile pelagic communities in terms of trace metal concentrations, but has little effect on the abundance and biodiversity of the local food web.
Subject(s)
Ecosystem , Gold , Mining , Water Pollutants, Chemical/analysis , Zooplankton/classification , Animals , Biodiversity , Environmental Monitoring , Fishes/metabolism , Food Chain , Mercury/analysis , Mercury/metabolism , Metals/analysis , Metals/metabolism , Papua New Guinea , Refuse Disposal , Water Pollutants, Chemical/metabolism , Zooplankton/growth & development , Zooplankton/metabolismABSTRACT
Little is known about the impacts of mine waste disposal, including deep-sea tailings, on tropical marine environments and this study presents the first account of this impact on deepwater fish communities. The Lihir gold mine in Papua New Guinea has deposited both excavated overburden and processed tailings slurry into the coastal environment since 1997. The abundances of fish species and trace metal concentrations in their tissues were compared between sites adjacent to and away from the mine. In this study (1999-2002), 975 fish of 98 species were caught. Significantly fewer fish were caught close to the mine than in neighbouring regions; the highest numbers were in regions distant from the mine. The catch rates of nine of the 17 most abundant species were lowest, and in three species were highest, close to the mine. There appears to be limited contamination in fish tissues caused by trace metals disposed as mine waste. Although arsenic (several species) and mercury (one species) were found in concentrations above Australian food standards. However, as in the baseline (pre-mine) sampling, it appears they are accumulating these metals mostly from naturally-occurring sources rather than the mine waste.
