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Ecotoxicological studies of the effects of heavy metals and hydrocarbons on Antarctic and temperate echinoderms

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Lane, A (2005) Ecotoxicological studies of the effects of heavy metals and hydrocarbons on Antarctic and temperate echinoderms. PhD thesis, University of Tasmania.

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Abstract

Contamination of Antarctic marine environments with heavy metals and
hydrocarbons has occurred as a result of human habitation and activities over the
past 100 years. Despite a commitment by Antarctic Treaty Nations to minimise
environmental harm and remediate existing contaminated sites, there is
insufficient data on the sensitivities of Antarctic marine species to set priorities or
targets for clean-up efforts or to establish guidelines for water and sediment
quality. As a pre-requisite to collecting these data there is need for relevant and
practical toxicity testing protocols for Antarctic species.
Morphological deformities of Abatus spp. heart urchins from contaminated sites
were quantitatively investigated. Urchins from the contaminated sites were found
to be smaller, flatter and wider, particularly those from the inshore areas closest to
the contamination source. Obvious deformities occurred in nearly 50% of the
inshore urchins. Metal concentrations in carbonate tests of urchins from these
sites appear to correlate with the observed morphological differences.
Techniques for the larval culture of echinoids with planktonic larvae are well
developed, however culture of brooding species has not previously been described.
Methods were developed for the collection, maintenance and transport of juvenile
Abatus spp. with juveniles that were removed from the brood pouch and then
reared for one year. This work has potential application to a range of biological
and toxic iological studies of brooding echinoids.
Juvenile Abatus ingens and A. nimrodi urchins were exposed to metals in seawater
for 10 days. Copper and zinc caused mortality at concentrations affecting larval
development in other echinoid species. In particular copper was toxic within
concentration ranges that may occur in contaminated Antarctic marine
environments.
To assess accumulation of metals by heart urchins, the temperate species
Echinocardium cordatum were exposed to sub-lethal concentrations of lead and
copper in sediments for 60 days. Chemical analysis of the carbonate shell at the
end of this period showed increased concentrations of copper in exposed animals, although results varied between and within individuals. Results of high resolution
elemental analysis suggest that the incorporation of metals occurs throughout the
carbonate test and not only in newly deposited shell material.
The toxicity of diesel in sediments to the Antarctic ophiuroid Ophiura crassa and
to the temperate urchin Echinocardium cordatum was examined over 10 days.
Undispersed diesel impacted on ophiuroid movement within 24 hours although
the effects were reduced over a longer period. Dispersed diesel was more toxic
than undispersed diesel to ophiuroids, causing high rates of mortality. E.
cordatum was not tested with dispersed diesel, but was far more sensitive to
undispersed diesel than 0. crassa, with mortality of all exposed animals at
concentrations 42 mg diesel kg dry sediment-1 .
The methods for culture and toxicological testing described in this thesis have
potential application to other related echinoderm species and toxicants. The
results of the studies have relevance to the development of water and sediment
quality guidelines for Antarctica.

Item Type: Thesis (PhD)
Keywords: Marine pollution, Hydrocarbons, Heavymetals, Echinodermata
Copyright Holders: The Author
Copyright Information:

Copyright 2005 the Author - The University is continuing to endeavour to trace the copyright owner(s) and in the meantime this item has been reproduced here in good faith. We would be pleased to hear from the copyright owner(s).

Additional Information:

For consultation only. No loan or photocopying permitted until 12 March 2007. Thesis (Ph.D.)--University of Tasmania, 2005. Includes bibliographical references

Date Deposited: 19 Dec 2014 02:47
Last Modified: 17 Jul 2017 23:29
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