Leviathan spotters having a whale of a time
The world’s largest fish has emerged in big numbers in the waters off Christmas Island.
The world’s largest fish has emerged in surprising numbers from the dark Java trench to feed on coral spawn in the warm waters off Christmas Island.
Whale sharks visit the remote Australian territory between November and March each year but locals can’t remember seeing this many at once. The Faulkners are among local families who have taken to their boats these school holidays to snorkel with the endangered species.
“It’s an awesome whale shark season — people have been seeing up to eight in one day,” Kirsty Faulkner said.
“There’s lots of coral spawn and cold currents bringing loads of food for them. Hopefully they will still be here for the crab spawning at the end of January.”
Whale sharks grow slowly and can reach up to 12m in length.
To feed, they open their mouths wide and let the water drain out through their gills, which are lined with hundreds of tiny teeth called gill rakers that catch plankton.
At Christmas Island, this includes the coral spawn from the tropical reef that circles the island and the larvae of red land crabs. Once every wet season, an estimated 50 million red crabs march out of the island’s monsoonal forest to lay their eggs in the sea on a receding high tide during the last quarter of the moon.
David Attenborough went to the island with a BBC crew to film the migration in 1990 and he has since described it as one of the world’s great natural wonders.
It is manna for whale sharks.
In Australia, whale sharks are best-known to visit the World Heritage-listed Ningaloo Reef, 1200km north of Perth, between March and June. About 180,000 tourists a year go to Ningaloo and the trade is sophisticated and heavily regulated: big tour boats rely on a network of spotter planes to make sure every passenger gets a chance to swim alongside a whale shark.
On Christmas Island, closer to Jakarta than Darwin, two small tourist operators take locals and visitors to dive and snorkel with dolphins, giant trevally, tropical fish and whale sharks.
Whale sharks movements were relatively unknown, but electronic tags are helping researchers learn more about them, including that one swam more than 8000km in 150 days. Another dived to a depth of almost 2000m in the Gulf of Mexico.
There have been few sightings in waters with temperatures below 22C.
In 2008, a tagged whale shark was detected on the Great Barrier Reef for the first time.
Despite their size, whale sharks are not a danger to humans.
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