Rare whale shark encounter for semi-sub passengers

10th of August 2022

Imagine coming face to face with the biggest fish in the sea – the whale shark. That’s just what happened to a group of lucky passengers with Great Adventures in a very rare encounter while they were seated in the semi-submarine at Moore Reef.

The whale shark, estimated to be 4 - 5 metres in length swam up close and alongside the semi-sub window as excited passengers looked on in awe. This vision was captured by one of the lucky passengers.

Quicksilver Group Environment and Compliance Manager Doug Baird said. “For what is the world’s largest fish, we really do know very little about them and their behaviour here on the east coast of Australia.” 

More often associated with the northern waters of Western Australia, whale shark encounters on the Great Barrier Reef are quite sporadic.

“We wouldn’t normally expect to see them here at this time of year. As plankton feeders you would expect likelier sightings around seasonal plankton blooms and coral spawning.”

This sighting is of great interest to researchers who have been working to identify a potential whale shark aggregation site in the far north regions of the Reef. 

As the largest fish in the sea reaching lengths of over 12 metres, whale sharks are docile fish feeding mostly on plankton, crab larvae and jellyfish, which they scoop up with their colossal gaping mouths while swimming close to the water’s surface. They are listed as a vulnerable species and prior to the mid 1980s there were less than 350 confirmed reports of whale sharks world-wide. 

Researchers are able to identify individuals from photographs by analysing the patterns of markings on their bodies - a bit like fingerprints. The whale shark’s back and sides are gray to brown with white spots among pale vertical and horizontal stripes, and its belly is white. The flattened head sports a blunt snout above its mouth with short barbels protruding from its nostrils. Its two dorsal fins are set rearward on its body, which ends in a large dual-lobbed caudal fin (or tail).