title: Effects of cadmium accumulation from suspended sediments and phytoplankton on the Oyster Saccostrea glomerata.
abstract: Metals are accumulated by filter feeding organisms via water, ingestion of suspended sediments or food. The uptake pathway can affect metal toxicity. Saccostrea glomerata were exposed to cadmium through cadmium-spiked suspended sediments (19 and 93μg/g dry mass) and cadmium-enriched phytoplankton (1.6-3μg/g dry mass) and cadmium uptake and effects measured. Oysters accumulated appreciable amounts of cadmium from both low and high cadmium spiked suspended sediment treatments (5.9±0.4μg/g and 23±2μg/g respectively compared to controls 0.97±0.05μg/g dry mass). Only a small amount of cadmium was accumulated by ingestion of cadmium-enriched phytoplankton (1.9±0.1μg/g compared to controls 1.2±0.1μg/g). In the cadmium spiked suspended sediment experiments, most cadmium was desorbed from sediments and cadmium concentrations in S. glomerata were significantly related to dissolved cadmium concentrations (4-21μg/L) in the overlying water. In the phytoplankton feeding experiment cadmium concentrations in overlying water were <0.01μg/L. In both exposure experiments, cadmium-exposed oysters showed a significant reduction in total antioxidant capacity and significantly increased lipid peroxidation and percentage of destabilised lysosomes. Destabilised lysosomes in the suspended sediments experiments also resulted from stress of exposure to the suspended sediments. The study demonstrated that exposure to cadmium via suspended sediments and to low concentrations of cadmium through the ingestion of phytoplankton, can cause sublethal stress to S. glomerata.
authors.affiliation: Ecochemistry Laboratory, Institute for Applied Ecology, University of Canberra, Bruce 2601, ACT, Australia.
authors.forename: Helena A
authors.initials: HA
authors.lastname: Schmitz
authors.affiliation: Ecochemistry Laboratory, Institute for Applied Ecology, University of Canberra, Bruce 2601, ACT, Australia. Electronic address: bill.maher@canberra.edu.au.
authors.forename: William A
authors.initials: WA
authors.lastname: Maher
authors.affiliation: Ecochemistry Laboratory, Institute for Applied Ecology, University of Canberra, Bruce 2601, ACT, Australia.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Taylor
authors.affiliation: Ecochemistry Laboratory, Institute for Applied Ecology, University of Canberra, Bruce 2601, ACT, Australia.
authors.forename: Frank
authors.initials: F
authors.lastname: Krikowa
mesh_terms: D000818:Animals; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity*; D019015:Geologic Sediments / Q000737:chemistry*; D000075322:Heavy Metal Poisoning; D015227:Lipid Peroxidation / Q000187:drug effects; D008247:Lysosomes / Q000187:drug effects; D010125:Ostreidae / Q000187:drug effects* / Q000378:metabolism*; D010839:Phytoplankton / Q000737:chemistry*; D011041:Poisoning; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium
keywords: Lipid peroxidation; Lysosomal destabilisation; Metal; Phytoplankton; Suspended sediments; Sydney rock oysters; Total antioxidant capacity