Australia is a 'goldmine' for undescribed tiny marine organisms, according to a University of Queensland scientist who specialises in classifying them.
With less than 15 percent of Australia's biodiversity described, let alone understood, taxonomist Dr Leslie Chisholm feels she has no shortage of creatures to study.
'We have to know what's there, before we can determine whether species are being lost,' she said.
'This is no small task since Australia has up to 20 percent of the world's biota but only one percent of the world's taxonomists (scientists who classify living organisms).
'The International Year of the Ocean highlights the importance of increasing knowledge to help us manage marine resources effectively.'
Dr Chisholm, a Parasitology Department postdoctoral fellow, is part of a formidable world-class team with access to unique marine specimens at the University's Heron Island Research Station, near Gladstone.
She is a leading authority on a cosmopolitan family of parasitic flatworms which live exclusively on sharks and stingrays. Members of the family Monocotylidae are found from eastern Australia, to America, the Northeastern Atlantic and the Mediterranean.
Almost one quarter of all known monocotylids have been recorded from Australian waters and Dr Chisholm's research indicates many new species remain to be described. However, because only 92 species have been described, and many more are suspected, the scientific classification (taxonomy) of the family is far from complete.
The work opens up a Pandora's box of questions about the biological association of parasites with sharks and rays - a most significant group of fishes. Is the presence or absence of these parasites on their hosts significant? Why are the parasites found on a diversity of host sites including the skin, gills, nose and cloaca ?
Dr Chisholm said the most recent comprehensive survey of Heron Island monocotylids was in the 1960s so her PhD thesis supervised by station director Dr Ian Whittington had aimed to systematically revise the group.
In the past few years since arriving from Canada, Dr Chisholm has described seven new species in waters around Heron Island, Moreton Bay and Tasmania and has discovered species known previously only in the northern hemisphere.
'Current knowledge of this family of parasites is inadequate, especially as it is not based on live specimens,' she said.
'Often structures not visible in preserved material are distinct in living animals, and freshly fixed specimens can be viewed with ease under scanning electron microscopes.'
Dr Chisholm is also describing the larvae of all new and previously described Australian species. Most larvae are undescribed so Dr Chisholm has already doubled the world's quantum of knowledge on these microscopic creatures. She is also investigating their biology and ecology.
Dr Chisholm said the flatworms shed eggs directly into warm tropical waters, and within seven to 14 days, small, ciliated larvae developed within the eggs. However, scientists did not know what factors triggered the eggs to hatch.
'No one knows how the free-swimming larvae find their hosts, or infect them, nor how they reach their final attachment site on the host,' she said. 'Even the creatures' longevity is unknown.'
Toronto-born Dr Chisholm literally saw the light to begin studying marine science. While on a family holiday in Florida, she wondered about the source of the glow on a Sanibel Island beach. No one could tell her: she later discovered the source to be tiny, bioluminescent planktonic organisms.
She completed an undergraduate degree in marine biology, followed by a master of science in marine ecology in 1988 (both from the University of Guelph in Canada).
In an attempt to escape the cold Canadian winters, she undertook her masters degree on tropical plankton with field work based at the University of the West Indies in Jamaica.
After working as a research associate at the University of Guelph for five years, she developed a keen interest in parasites which live on sharks and rays, and requested to undertake a PhD in Australia to work with Dr Whittington, one of the world's respected authorities on monogenean parasites.
In 1995 she won a $1200 bursary from the Australian Federation of University Women and she has attracted University of Queensland Postgraduate Research, and Overseas Postgraduate Research Scholarships.
Dr Chisholm's many awards include a Natural Sciences and Engineering Research Council of Canada (NSERC) postgraduate scholarship, and this year NSERC also awarded her a two-year postdoctoral research fellowship.
These awards are rarely allowed to be taken outside Canada. However, Dr Chisholm was able to make a strong case why the fellowship should be taken at the University of Queensland.
The University's Heron Island Research Station and world-class scientific facilities allow her access to representatives of all six subfamilies and many genera of the Monocotylidae found in Australian waters.
For further information, contact Dr Chisholm, telephone 07 3365 6974, email: l.chisholm@mailbox.uq.edu.au
phone 07 3365 2705/07 3365 2944, email: m.bennett@mailbox.uq.edu.au, Dr Sue Bennett, telephone 07 3365 5756, email: s.bennett@mailbox.uq.edu.au or Dr Adrian Bradley, telephone 07 3365 3386, email: a.bradley@mailbox.uq.edu.au
