Tagging Whale sharks in the Seychelles

Nature Facts

Where: Marine Conservation Society, Seychelles International Airport, Mahé, Seychelles, Indian Ocean
When: October
Nature facts: 
Whale sharks are filter feeders which can grow up to 60 feet in length and weight up to 34 tonnes. The Far Eastern restaurant business as made them an endangered species

One of the chief concerns of the Marine Conservation Society, based at Seychelles International Airport in Mahé, is to save the Whale shark from extinction.

About Whale Sharks

Whale sharks have very distinctive colourings; their dorsal surface is covered with white spots and stripes. They are known as filter feeders, feeding on zooplankton, small fish, and squid. Their large mouths engulf huge volumes of water which is filtered by a sieve-like organ inside the gill slits on the sides of their head. Whale sharks are approximately 22 to 30 feet long, but they can grow to as long as 60 feet and weigh up to 34 tonnes. Considering that a big elephant weighs six tonnes, the Whale shark is a very heavy beast indeed.

Monitoring Whale Sharks

Whale sharks tend to inhabit the warm waters around the Equatorial belt. Very little is known about them, so monitoring is essential to form an understanding of their behaviour, subsistence, and mating seasons in order to save them. Over the last five years, Whale sharks in the Indian Ocean have been slaughtered to cater for the Far Eastern restaurant business and their numbers have vastly declined to the point that they’re now considered an endangered species.

Whale sharks are the biggest fish on the planet and they’re easier to spot in the waters than almost anything. But because they’re a threatened species, and because they’re very individualistic and don’t swim in schools, they’re not easy to find, so initially whale conservationists go plane-spotting for the sharks using planes. The microlight is the aircraft of choice because it can fly low and it’s a lot cheaper than a helicopter or a cessna.

Tagging Whale Sharks in the Seychelles

In October, the sharks arrive to bask in the deep blue, warm waters of the Indian Ocean and feed off plankton on the islands of the Seychelles, so this is the best time to tag and monitor the whales. This is done by someone diving down and harpooning the back of the shark with an electronic tag, inscribed with ‘S’ for the Seychelles, a different colour for each year, and a number to identify the individual shark. Often the shark will shake off their old tag, so underwater photos are taken to try and identify the ones that have returned. There have been over 70 sharks tagged in the first four years since the project started in 2001.

Tourists can, for a fee, help out with spotting the Whale sharks with David Rowat from theMarine Conservation Society Seychelles by taking out a microlight to survey the sea from the air in the morning. In the afternoon, you go on the boat with the scientists and snorkel with the Whale sharks, all under the supervision of David and his team. There are strict rules: you can’t come closer than four metres (thirteen feet) from the shark, no flash photography may be used, and no more than eight people can be around a Whale shark at any one time.

More Information

Marine Conservation Society Seychelles
Look at their website to see how you can help the whale sharks from being hunted.

Underwater Centre Seychelles
Coral Strand Hotel
Beau Vallon
PO Box 384
Mahé, Seychelles
Telephone: 248 247 165

This is one of the best diving centres in the Seychelles, run by Scotland-born Glynis, who can take you to see amazing marine life. Check out their website for rates and details. Glynis’s husband runs the The Marine Conservation Society Seychelles.

By Susi O’Neill

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