What is a whale shark?
The whale shark is the world's largest fish, a gentle filter-feeding shark that can grow to more than 12 metres long. Each year, whale sharks gather at Ningaloo Reef in Western Australia.
Despite their huge size, whale sharks feed on tiny plankton, fish eggs and small fish, filtering them from the water through their wide mouths and gill rakers. They pose no danger to swimmers.
Each whale shark has a unique pattern of white spots on its dark grey back. Scientists use photographs of these patterns to identify individuals and track them across years.
Swimming with whale sharks
From about March to July, whale sharks arrive at Ningaloo, likely drawn by plankton blooms after coral spawning. Licensed tours from Exmouth and Coral Bay take swimmers out to snorkel beside them.
Strict rules require swimmers to stay several metres away and not touch the sharks.
Whale sharks are listed as endangered globally, threatened by fishing in some countries and ship strikes. Ningaloo's tours have become a model for responsible wildlife tourism and help fund research. Tags fitted to some sharks have shown that they travel thousands of kilometres into the Indian Ocean and toward Southeast Asia after leaving the reef.
Did You Know?
Whale sharks are found in tropical oceans worldwide, but Ningaloo is one of the most reliable places to see them.