SATELLITE TAG STUDY REVEALS PHILIPPINE WATERS ARE INCREDIBLY IMPORTANT FOR ENDANGERED WHALE SHARKS

A new scientific study has tracked juvenile whale sharks across the Philippines, discovering that all the subjects stayed within the country’s waters over the one-year tracking period, emphasising the importance of the archipelago for the species.

By attaching Wildlife Computers SPOT5 satellite tags, researchers from Large Marine Vertebrates Research Institute Philippines (LAMAVE), Marine Megafauna Foundation (MMF) and Tubbataha Management Office (TMO) were able to follow the movements of juvenile whale sharks in near real-time to gain an insight into their behaviour. The tags work by communicating with passing ARGOS satellites, transmitting a location whenever a tagged whale shark breaks the surface.

The study is the most complete tracking study of whale sharks in the country, with satellite tags deployed on different individuals at multiple sites. Seventeen individual whale sharks were tagged in three different locations in the Philippines: Panaon Island, northern Mindanao, and Tubbataha Reefs Natural Park. Tagging took place between April 2015 and April 2016. All tagged whale sharks were juveniles, ranging in size between four-and-a-half and seven metres, with 73 percent of the subjects male.

The Philippines is an important hotspot for whale sharks and globally hosts the third largest-known population of whale sharks. The species has been protected in the Philippines since 1998, but 2016 saw the species move from “Vulnerable” to “Endangered” on the IUCN Red List of Threatened Species. This occurred after a population decline of more than 50 percent, largely caused by continued exploitation in the Indo-Pacific. Particularly in Southeast Asia, concerns remain due to continued fishing in regional waters. Thus, understanding the movements of whale sharks in the Philippines is vital if we are to identify conservation priorities for the species.