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
The common practice of freezing sediment cores for later chemical investigation was shown to be inappropriate for samples containing selenium. Pore waters from frozen estuarine sediment cores contained up to eighty times the selenium content of those extracted from chilled but unfrozen cores. Experiments suggested that the increase in selenium concentrations resulted from rupturing the cells of selenium-accumulating bacteria present in the samples.
Subject(s)
Chemistry Techniques, Analytical/methods , Freezing , Geologic Sediments/analysis , Selenium/chemistry , Water/analysis , Centrifugation , Escherichia coli/metabolism , New South Wales , Selenium/pharmacokinetics , Spectrometry, FluorescenceABSTRACT
Design details and operating instructions are provided for a sediment corer that can be converted into a reactor for the measurement of the fluxes of contaminants from sediments to overlying waters. The corer-reactor permits measurements, under controlled laboratory conditions, on intact, largely undisturbed sediment cores, without significantly perturbing the physical and chemical conditions found in the field. The design can be constructed in-house for around US dollar 240 (A dollar 400) (excluding motor and corer lid), making it a relatively inexpensive system.
Subject(s)
Environmental Monitoring/methods , Environmental Pollutants/analysis , Geologic Sediments/chemistry , Specimen Handling , Water Pollutants/analysisABSTRACT
We have previously shown that the peptide FDTGAFDPDWPA is a mimetic of the group B streptococcal type III capsular polysaccharide (CPS(III)). It binds to anti-CPS(III) antibodies and can be used to immunize mice and produce anti-CPS(III). In this paper we investigate the molecular mechanisms underlying this peptide-carbohydrate mimicry in two ways. First, we have examined the conformation of the peptide by NMR spectroscopy in water. Next, we have produced monoclonal anti-peptide and anti-CPS(III) antibodies, compared their fine specificity, and have sequenced them. The results indicate that the peptide assumes a conformation that may be similar to that of the CPS(III) in solution and that the peptide and CPS(III) elicit an overlapping repertoire of antibodies.
