Fears that whale shark numbers are in decline have been confirmed even though a large number of countries have ceased harvesting the world’s largest fish.
“Because these animals migrate up to 12,000 km, Australia’s whale shark population is shared with many other countries in South-East Asia and around the Indian Ocean,” Dr Mark Meekan, of the Australian Institute of Marine Science, said.
However, the long life spans of the giant sharks, believed to be more than 70 years, indicate that they will take a long time to recover from over-harvesting.
The last commercial whale shark fishery has recently closed, but there is still some local fishing and possibly some illegal harvesting.
Photographs taken of whale sharks congregating off Ningaloo Reef in Western Australia over the past 12 years show that numbers of sharks are declining.
Charles Darwin University