Whale sharks tagged in satellite tracking project

Scientists are tagging whale sharks in the region in an effort to monitor their movements, and make a case for protecting the animal, which is at risk of extinction.
David Robinson tags his first whale shark, an eight-metre female named Amna. It is hoped the data from the tag, and of 25 others, will help scientists understand the role local waters play in the life of the shark.
David Robinson tags his first whale shark, an eight-metre female named Amna. It is hoped the data from the tag, and of 25 others, will help scientists understand the role local waters play in the life of the shark.

Amna, an eight-metre female whale shark found swimming near an oil rig on April 23, was the first of her kind to be tagged in the Arabian Gulf.

In the next five years, an additional 25 whale sharks will be tagged, as researchers attempt to demystify the behaviour of the world's largest fish.

The whale shark, which can grow up to 12 metres long and weigh 21 tonnes, is notable not just for its size. It also migrates for tremendous distances and dives to depths of one kilometre. However, it is also at risk of extinction, according to the International Union for Conservation of Nature.

David Robinson, a researcher at the Heriot-Watt University Dubai, is among a handful of researchers in the Gulf who are attempting to learn more about the shark's population size and habits.

"We do not know if they stay regional, if they migrate to and from this area, or if they are simply passing through," said Mr Robinson, who is studying for his doctorate at the university.

The satellite tags will track the sharks for six months before detaching automatically. The data from the tags will form part of Mr Robinson's PhD dissertation and will help conservationists understand the role regional waters play in the life of the animal.

The information will help conservationists push for stronger legislation to protect the sharks in the countries whose waters they inhabit. While the whale shark is already protected under UAE law, other countries in the GCC lack such regulations.

"To be able to protect a species, we must first know how that species utilises its environment," Mr Robinson said.

In addition to tracking the sharks' migratory routes, the tags also record how deep they are swimming. Tracking the sharks' depth provides scientists an insight into their diets, as well as what temperatures they prefer.

Despite their size, whale sharks are filter feeders, living off microscopic plankton in the water.

Presently, little is known about the behaviour of sharks in the region. In the Indian Ocean, the fish are predominantly male. However, the Gulf region appears to have higher populations of females and juveniles, which, according to the wildlife documentary filmmaker Jonathan Ali Khan, means the region may act as a nursery and breeding ground for the sharks.

Historically, waters in the Gulf region have been heavily protected, making them ideal breeding grounds.

"Until the advent of the oil era, the shallow areas of the region have been quite void of human interference," said Mr Ali Khan.

"Now, in under 50 years, there has been a changed dynamic of the sea and our interaction with marine life," he added.

Conservationists have launched other efforts to learn more about the lives of whale sharks. In 2009, an online database was launched to record sightings.

The website acts as the Gulf arm of a global whale shark database created in 2003. The site enables anyone to upload images and details of sightings. Mr Ali Khan estimated that he has already increased the information available about the shark's life in the region by 80 to 100 per cent.

The global database utilises a computer software tool that can identify individual whale sharks by the unique spot patterns on their skin behind the gills. For conservationists, the information is an important tool in convincing decision-makers of the importance of regional waters to the shark's international migrations.

"We need to broaden the outlook to ensure the areas where the whale sharks are known to frequent have protective measures taken," Mr Ali Khan said.

mdetrie@thenational.ae

Published: May 9, 2011 04:00 AM

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