Named for the distinctive white tips of their fins, sharks typically school in schools around reefs during the day and are a popular attraction for divers.
They become active at night to hunt small fish and other animals.
Photos of one of the sharks with what appeared to be spots and lesions on the head went viral on social media in April after it was taken by an underwater photographer off the coast of Sabah state on the island of Borneo.
Soon after, divers from Sipadan Island, a famous nearby diving destination, and a team of experts from state university, government, and conservation groups began to see the disease. skin in each group of sharks encountered.
Trying to diagnose what could be causing the illness, the team found that the sea surface temperature at Sipadan had reached 29.5 ° C (85.1 ° F) in May, a degree higher than that of 1985.
“We can almost certainly attribute the warming of the ocean to a role in what we see with sick sharks in Sipadan,” said Davies Austin Spiji, senior marine biologist with the Reef Guardian conservation group.
The reported sightings coincide with reports of coral bleaching in the region, according to Dr Mohamed Shariff Mohamed Din, professor of aquatic veterinary studies at Universiti Putra Malaysia.
“We cannot ignore that changes are happening there due to the higher temperatures,” he said.