Rare, Tiny Ocean Find in WA waters

Date: 17 June 2004

The Phaeodaria measures only 1.4 mm

A miniscule marine creature caught during a recent Indian Ocean research voyage is believed to be the first of its kind identified in the Southern Hemisphere.

The single celled organism, supporting what looks like 6 legs is a phaeodaria from the family coelodendridae, also known as a radiolarian. Measuring only 1.4 mm, the organism was found during an investigation of ocean eddies by the National Marine Facility, Southern Surveyor.

"It was a case of being in the right place at the right time with the right people," says PhD student Harriet Paterson, who discovered the radiolarian. Harriet works with the Strategic Research Fund for the Marine Environment (SRFME) a joint CSIRO-West Australian Government marine research team based at Floreat, Perth.

"Our objective was to collect samples of marine life in ocean eddies and this was a complete surprise to us, and I’m sure to other researchers in this field from Northern Hemisphere institutions," Ms Paterson said.

The phaeodaria, from the family coelodendridae, is a single celled organism supporting what looks like 6 legs. 3D model image by Dirk Slawinski. (Click on image for larger view).

Ms Paterson detailed her research to colleagues during a science symposium in Perth yesterday (June 16).

The Director of SRFME, Dr John Keesing, said the discovery is an example of how state and federal agencies are coming together to tackle the problem of exploring and managing Australia's vast and valuable ocean resources.

"Australia's territory is 70% ocean. We need more ocean scientists. We need to be able to provide hard scientific facts about our oceans that will allow legislators, regulators and industry to be able to address the challenge of managing our ocean resources.

"The West Australian Government, CSIRO Marine and Atmospheric Research and the CSIRO Wealth from Oceans Flagship have come together to provide a program to train and supervise new PhD students in the area of marine science. This discovery is a direct result of that program," said Dr Keesing.

This sea surface temperature image highlights the warm-core and cold-core eddies centred near 31.2S 111.6E and 30.7S 110.1E. Using satellite images such as this, oceanographers in Hobart guided the Southern Surveyor to the eddies for sampling. (click on image for larger view).

The find has excited scientists researching the microzooplankton world. The pheodaria was captured in a sediment trap deployed within an ‘upwelling’ eddy bringing cold and nutrient-rich deep ocean water to the surface by Dr Stephan Pesant a member of the University of Western Australia team lead by Dr Anya Waite, Centre for Water Research.

The microzooplankton species is understood to live from depths of 100 to 5,000 metres. Its food range extends from ocean algae to tiny shellfish. It consumes prey in the same manner as a spider, remineralising part of the ‘ocean snow’ and helping to sustain other small forms of marine life.

Ms Paterson has searched the scientific literature and believe this is the first sample to be found in the Southern Hemisphere.

The first sample was recorded during the world’s first oceanographic voyage by the British ship Challenger in the 1870’s, and then more than a century later, US scientist Dr Neil Swanberg collected 18 specimens down to a depth of 500 metres in one voyage from a submersible in 1986.

Links:

The biophysical oceanography off Western Australia

More information:

Craig Macaulay: 03-6232 5219, e-mail

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