Where do whale sharks spend the Australian summer?

Baby whale shark. Photo: Flickr Creative Commons/Drew and Marissa.

BRISBANE (AUSTRALIA)- Swimming with whale sharks winter and autumn is one of the tourist attractions of the Ningaloo reef in Western Australia. But where do the world’s largest fish spend their summers? 

In a world-first, researchers from The University of Queensland (UQ) and the non-profit ECOCEAN have tracked and recorded a full return migration of whale sharks to and from Ningaloo Reef in Western Australia.

Ningaloo reef

UQ graduate and ECOCEAN marine biologist Samantha Reynolds said the study revealed surprising insights into the importance of the Ningaloo Reef area.

“Our tagged whale sharks were tracked returning to Ningaloo Reef throughout the year, and our modelling suggests that it provides suitable habitat for them year-round,” Ms Reynolds said.

Ecotourism

Reynolds: “The ecotourism industry takes visitors swimming with whale sharks at Ningaloo Reef in autumn and winter, but until now the creatures’ whereabouts at other times of the year has remained a mystery.

“Whale shark season at Ningaloo could last all year,” Ms Reynolds said. “This is valuable information for the eco-tourism industry and could provide a boon for the local Ningaloo economy. It’s also vital information for the long-term management and conservation of whale sharks. They are an endangered species. We need to know which areas are critical habitat for them, so we can protect them into the future.”

Whale shark

Satellite tracking

Ms Reynolds said the work had been part of the most extensive satellite tracking study of whale sharks in Australia. It identified areas along the WA coast, in the Timor Sea and in Indonesian and international waters that could be important whale shark habitat. “Our study highlights the need for international co-operation for the protection of whale sharks,” Ms Reynolds said.

“Many of these areas are not designated as Marine Protected Areas and some of the tagged sharks we studied travelled to areas where they could be under threat from ship strike, pollution or targeted fishing.

”The conservation status of whale sharks was changed from vulnerable to endangered last year, because of these threats.”

Whale sharks (Rhincodon typus) are slow-moving filter-feeding carpet sharks, living to 80 years, with the largest confirmed individual weighing about 21.5t with a length of 12.65m.

The research, published in Diversity and Distributions, continues this month with more satellite tagging. ECOCEAN is a finalist in the Innovation in Citizen Science Eureka Prize category announced tonight.