title: Combining the use of gradients and reference areas to study bioaccumulation in wild oysters in the Hunter River estuary, New South Wales, Australia.
abstract: Two approaches for measuring the effects of human activities on aquatic biota are gradient studies and comparison of impacted areas to external references. Wild oysters were sampled at 12 sites adjacent to, upstream and downstream of a steelworks in the Hunter River estuary and in two reference estuaries. Regression analyses for the Hunter indicated reduced concentrations with distance from the point source for some metals and PAHs. Data compared from the reference estuaries to the two sites nearest and the two furthest from the point source in the Hunter indicated elevated concentrations of contaminants both near the point source and on an estuary-wide basis. The gradient approach was useful in identifying the industrial effluent as a point source for bioavailable chemicals. Combining this with the use of reference estuaries provided a broad geographic context in which to interpret results from the Hunter and identified estuary-wide effects.
authors.affiliation: The Ecology Lab Pty Ltd., 4 Green Street, Brookvale, New South Wales 2100, Australia. mls@theecologylab.com.au
authors.forename: Marcus P
authors.initials: MP
authors.lastname: Lincoln-Smith
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Cooper
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D049872:Bivalvia / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data*; D008401:Gas Chromatography-Mass Spectrometry; D005843:Geography; D008669:Metallurgy; D019216:Metals, Heavy / Q000032:analysis; D009517:New South Wales; D010636:Phenols / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D012044:Regression Analysis; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D010636:Phenols; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical