Whale shark numbers at Western Australia's Ningaloo Reef are declining, according to Charles Darwin University researcher Dr Corey Bradshaw.
Dr Bradshaw, senior research fellow, School for Environmental Research, has used records over 12 years to monitor whale shark population trends.
The sharks, which migrate up to 12,000 kilometres, are harvested by many countries for commercial purposes.
Dr Bradshaw, who worked on the research project with marine scientist Dr Mark Meekan, said understanding more about their movements and slow reproductive biology were the keys to their protection.
‘For such a rapid decline to be observed in such a long lived species suggests a strong mortality source,’ he further explained.
Paul Gamblin of the World Wildlife Fund said the federal government should raise the issue with our Asian neighbours to discuss how to reduce the take of whale sharks.
‘The whale sharks draw thousands of visitors to Ningaloo Reef every year and are used heavily in WA tourism, and as a result need much better protection.’