KEY POINTS:
The 1000th whale shark, a rare and threatened species, has been discovered by researchers using a global programme in which eco-tourists and scientists identify new sharks and lodge photographs on an online library.
"It's a major milestone, for science and for conservation," said Ecocean project leader Brad Norman in Australia.
"It was achieved with the help of ordinary people worldwide who want to study and protect this wonderful creature," Norman said yesterday.
The whale shark is the world's largest fish, a slow-moving filter feeder that can grow to around 12m and weigh up to 21 tonnes.
However, it is difficult to study, remaining in the deep ocean for months and only rarely rising towards the surface.
Ecocean tracks individual whale sharks around the world's oceans using a web-based photo-ID library which catalogues each whale's unique spots.
Researchers and eco-tourists submit images, which are logged to reveal a picture of whale shark movements and behaviour.
The 1000th whale shark was recently reported by marine biologist Simon Piercea in Mozambique.
Piercea has contributed more than 100 sharks from his three-year study in Mozambique.
"We can expect there to be substantially more than 1000 sharks alive in the world today," said Norman. "But, even so, it is still a very tiny global population that needs close monitoring to ensure its survival."
Participation in the Ecocean library has increased dramatically in recent years. It took three years to identify the 500th shark but only one extra year to reach 1000.
Ecocean's website tells readers how to photograph a whale shark, warning swimmers to stay at least 3m from the shark for fear of upsetting it.
It also explains how to photograph the left and right side spot patterns above the pectoral fins for identification.
"We're calling on the public worldwide to become 'citizen scientists' and help us study this wonderful animal by logging their images and sighting details," said Norman.
"The data will help us determine their numbers, movements and identify critical breeding and feeding grounds which need to be protected.
"This will build a better understanding of this threatened species and help save the largest fish in the ocean from extinction."
- REUTERS
* Ecocean Whale Shark Photo-identification Library: www.whaleshark.org