Secrets of endangered whale shark revealed

ENDANGERED WHALE sharks, gathering en masse at just a handful of locations around the world, have long perplexed conservationists worldwide with their unusual habits.

Known as the world’s largest fish, they often gather offshore, but only at 20 locations including in Australia, the Maldives and Mexico. Now, a new study by the University of York in collaboration with the Maldives Whale Shark Research Programme has uncovered one of their secrets.

The shark ‘aggregation sites’ show many common characteristics, they say, and are all in areas of warm, shallow water in close proximity to a sharp sea-floor drop off into deep water. Such sites, researchers suggest, provide an ideal setting for the filterfeeding sharks to search for food in both deep water and the warm shallows.

Dr Bryce Stewart from the Environment Department at the University of York, supervising author of the study alongside lead author Joshua Copping, said: “Sharks are ectotherms, which means they depend on external sources of body heat.

“Because they may dive down to feed at depths of more than 1,900 metres (2,077 yards), where the water temperature can be as cold as four degrees, they need somewhere close by to rest and get their body temperature back up.

“Steep slopes in the sea bed also cause an upwelling of sea currents that stimulate plankton and small crustaceans such as krill that the whale sharks feed on.”

The new insights will help inform conservation efforts for this mysterious species, say the researchers.

“The more we know about the biology of whale sharks the more we can protect them and this research may help us to predict where whale sharks might move to as our climate changes,” added Dr Stewart.