Philippines play vital role for whale sharks

A comprehensive tracking study of juvenile whale sharks show the importance of the Philippine archipelago in their migration patterns through Indo-Pacific waters.

Researchers from Large Marine Vertebrates Research Institute Philippines, Marine Megafauna Foundation and Tubbataha Management Office attached Wildlife Computers SPOT5 satellite tags to juvenile whale sharks to follow the movements in near real-time to gain an insight into their behavior. The finding were published in PeerJ—the Journal of Life and Environmental Sciences.

Seven individual whale sharks, ranging in size between 4.5—7 meters, were tagged between April 2015 and April 2016 in three different locations in the Philippines: Panaon Island (Southern Leyte), northern Mindanao (Misamis Oriental and Surigao del Norte) and Tubbataha Reefs Natural Park (Palawan).

According to their findings, the researchers discovered that the tracks from the tags showed that all whale sharks stayed within the Philippines over the tracking period, emphasising the importance of the archipelago for the species. The longest track observed was from a whale shark originally tagged in Tubbataha Reefs Natural Park, which appeared to swim through the Sulu and Bohol Seas and into the Pacific, a journey accumulating over 2,500 km in length. While whale sharks are not known for their speed, results revealed that one individual whale shark was averaging 47km a day, further emphasizing the species’ mobile tendencies.

“This research highlights the high mobility of whale sharks, even juveniles, and the need for broader scale management and conservation plans for this endangered species,” lead author Gonzalo Araujo said via press release.

According to WhaleSharks.org, the Philippines is home to the third largest known population of whale sharks. The species has been protected in the Philippines since 1998, globally the species was uplisted in 2016 to ‘endangered to extinction’ in the IUCN Red List of Threatened Species due to a population decline of more than 50%, largely caused by continued exploitation in the Indo-Pacific. Particularly in South East Asia, concerns remain due to continued fishing in regional waters; understanding the movements of whale sharks in the Philippines is vital if we are to identify conservation priorities for the species.