Study finds whale sharks homebodies
Teenage humans are well known for their ability to lock themselves in their rooms and never stray too far, and it seems young whale shark world may be no different.
Researchers from the University of Western Australia, Australian Institute of Marine Science and collaborators across the Indian Ocean have found juvenile male whale sharks don’t venture too far from home.
The researchers used photoidentification data, collected by citizen scientist, including crews working on the tour boats, and researchers, to assess the connectedness of five whale shark aggregation sites across the Indian Ocean over a decade.
After sifting through more than 6000 photos, they found on average 35 percent of whale sharks were seen again at the same site in more than one year but no sharks were found to have moved across the Indian Ocean.
UWA Oceans Institute and AIMS PhD researcher Samantha Andrzejaczek said the researchers had initially thought the juveniles crossed oceans to visit other important sites during their migration.
“Whale sharks are under threat from human impacts of hunting and ship strike and it makes it much easier to plan for conservation if we only have to deal with neighbouring countries in each region rather than localities spread across the entire Indian Ocean,” she said.
“Our young males don’t seem in any hurry to move on from their feeding grounds at Ningaloo — we have some individuals that have now been sighted here for 19 years and have even matured.”
Most of the whale sharks at Ningaloo are male teenagers.
Study co-author Mark Meekan said adult whale sharks still proved elusive in the Indian Ocean.
“We know the teenage males are homebodies, but that does not necessarily apply to the rest of the population,” he said.