04 September 2012
New Caledonia is home to the biggest coral reef lagoon and the second biggest coral reef on the planet. Coral reefs, essential to the world's ecosystems, are home to more than 25% of global marine biodiversity but comprise less than 0.1% of the Earth's ocean surface. They are considered biological "hotspots" because they are especially rich in marine species. Parasites play a major role in species evolution and the maintenance of populations and ecosystems. However the role of parasites is little known or appreciated.
South Australian Museum Scientist, Associate Professor Ian Whittington, and Honorary Research Associate at the Museum, Professor Ian Beveridge (University of Melbourne) are among an international research team of eight scientists from Australia, Britain, Czech Republic, and France. Directed by Jean-Lou Justine at the National Museum of Natural History in Paris, the team are embarking on an eight year study investigating parasite biodiversity on fish living in New Caledonia's tropical lagoon.
Their study found that the number of fish parasites is at least ten times the number of fish species in coral reefs (for fish of similar or greater size to the species in the four families studied). Therefore extinction of a fish species on this coral reef would very likely lead to the co-extinction at least ten parasite species associated with it. The disappearance of these parasites, although insignificant at first glance, would result in a biodiversity loss ten times higher. The consequences of such extinctions for the balance of coral reefs and species evolution in general are incalculable.
The Director of the South Australian Museum, Professor Suzanne Miller, says "the findings of this study provide a key insight into the aquatic biodiversity of the Pacific region. Associate Professor Whittington and his colleagues have effectively illustrated the complex relationships between marine organisms and their fragility in the face of climate change and other environmental disturbances."
The team's investigation primarily focused on traditional parasite morphology – with an emphasis on crustaceans, external and internal flukes, tapeworms and roundworms. The aim was to estimate the number of parasite species from reef fish and the number of host-parasite combinations possible, and give a clear picture of marine biodiversity in the region. The results of this study are published this week in the online open access journal Aquatic Biosystems.
The parasite and certain fish material collected and studied is held in several natural history museums across the world including the South Australian Museum's Australian Helminthological Collection in Adelaide. This collection is an internationally renowned collection of parasitic worms established with support from the Australian Society for Parasitology. The material is also held in the Czech Republic, France, UK and USA. All these collections are available to the scientific community for further studies. This emphasises the importance of preserving and increasing the collections of natural history museums. Scientists' pioneering work in this area and the collections will serve as a reference for similar studies on other coral reefs.
- Jean-Lou Justine, UMR 7138 Systematics, Adaptation, Evolution, Muséum National d'Histoire Naturelle, Paris, France
- Ian Beveridge, Department of Veterinary Science, University of Melbourne, Australia
- Geoffrey A. Boxshall, Department of Zoology, Natural History Museum, London, UK
- Rod A. Bray, Department of Zoology, Natural History Museum, London, UK
- Terrence L. Miller, Biodiversity Program, Queensland Museum, Queensland, Australia
- František Moravec, Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, Branišovská, Czech Republic
- John Paul Trilles, Team ecophysiological adaptations and Ontogeny, UMR 5119 (CNRS-IRD-UM1-UM2-IFREMER), Université Montpellier 2, France
- Ian D. Whittington, Monogenean Research Laboratory, The South Australian Museum & Marine Parasitology Laboratory, & Australian Centre for Evolutionary Biology and Biodiversity, The University of Adelaide, Australia