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Seawater temperature effect on metal accumulation and toxicity in the subantarctic Macquarie Island isopod, Exosphaeroma gigas


Lewis, A and King, CK and Hill, NA and Cooper, A and Townsend, AT and Mondon, JA, Seawater temperature effect on metal accumulation and toxicity in the subantarctic Macquarie Island isopod, Exosphaeroma gigas, Aquatic Toxicology, 177 pp. 333-342. ISSN 0166-445X (2016) [Refereed Article]

Copyright Statement

Copyright 2016 Elsevier B.V.

DOI: doi:10.1016/j.aquatox.2016.06.002


Very little is currently known of subantarctic nearshore invertebrates’ sensitivity to environmental metals and the role of temperature in this relationship. This study investigated Cu and Zn toxicity in the common subantarctic intertidal isopod, Exosphaeroma gigas, and the influence of temperature on Cu toxicity and bioaccumulation kinetics. Adult E. gigas are insensitive to Cu and Zn at concentrations of 3200 and 7400 μg/L respectively in non-renewal tests at 5.5 °C (ambient subtidal temperature) over 14 days. Under renewed exposures over the same temperature and time period the LC50 for copper was 2204 μg/L. A 10-fold increase in Cu body burden occurred relative to zinc, indicating E. gigas has different strategies for regulating the two metals. Copper toxicity and time to mortality both increased with elevated temperature. However, temperature did not significantly affect Cu uptake rate and efflux rate constants derived from biodynamic modelling at lower Cu concentrations. These results may be attributable to E. gigas being an intertidal species with physiological mechanisms adapted to fluctuating environmental conditions. Cu concentrations required to elicit a toxicity response indicates that E. gigas would not be directly threatened by current levels of Cu or Zn present in Macquarie Island intertidal habitats, with the associated elevated temperature fluctuations. This study provides evidence that the sensitivity of this subantarctic intertidal species to metal contaminants is not as high as expected, and which has significance for the derivation of relevant guidelines specific to this distinct subpolar region of the world.

Item Details

Item Type:Refereed Article
Keywords:ecotoxicology, copper, Macquarie Island, Exosphaeroma gigas, zinc, toxicity, subantarctic, temperature, bioaccumulation, biodynamic modelling
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Environmental Management
Objective Group:Management of Antarctic and Southern Ocean environments
Objective Field:Management of Antarctic and Southern Ocean environments not elsewhere classified
UTAS Author:Hill, NA (Dr Nicole Hill)
UTAS Author:Townsend, AT (Associate Professor Ashley Townsend)
ID Code:109641
Year Published:2016
Web of Science® Times Cited:7
Deposited By:Ecology and Biodiversity
Deposited On:2016-06-24
Last Modified:2018-04-13

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