Dec 26, 2007, 8:57 GMT
Washington - Gentle whale sharks are thriving in western Australia's Ningaloo reef area thanks to a successful eco-tourism programme, according to scientists who have been studying the 'fingerprints' of the sea's largest fish.
In a study published Wednesday in the journal Ecological Applications, Australian marine scientist Brad Norman teamed up with an astronomer and computer programmer to develop pattern-recognition software to identify the unique white lines and spots on the flanks of the white shark.
Starting in 1995, the software was used to help the authors keep track of individual whale sharks - a non-predatory fish that eats tiny zooplankton - and helped them determine that more whale sharks were returning to the northern area of Ningaloo Marine Park from season to season.
The findings suggested that the whale-shark population was growing and that about two-thirds of the sharks were repeat visitors.
The sharks range up to 20 metres in length, weigh up to 20 tonnes, and have broad, flattened heads. They are listed as a rare species, and inhabit tropical and warm seas, including the western Atlantic and southern Pacific, according to the study.
The authors said the study - based on 5,100 underwater images collected by hundreds of researchers, divers, and ecotourists - shows the park's management guidelines were working. The number was ten times the size of samples in previous whale-shark studies, the authors said.
'Applying these guidelines to other locations along whale shark migration routes may offer a viable alternative to hunting these fish, one that yields both economic and conservation benefits,' said Norman in a statement before the article appeared.
The software was developed by US computer programmer Jason Holmberg and astronomer Zaven Arzoumanian, who adapted software originally designed for the Hubble space telescope.
To study whale sharks in a meaningful way, we really had to rethink how we collect data and how we analyze it,' said Holmberg.
Whale sharks are a big draw to the Ningaloo marine park, where tourists pay to swim close to the sharks.
The journal is published by the Ecological Society of America.
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