Highly-endangered Irrawaddy dolphin discovered in Bicol waters for the first time

A highly-endangered Irrawaddy dolphin has been discovered off the shore of Calabanga, Camarines Sur, the first time that its kind was sighted in Bicol waters.

Nicknamed Calab by the Bureau of Fisheries and Aquatic Resources (BFAR) and the Philippine Marine Mammals Stranding Network (PMMSN), the dolphin was a healthy young female that died after it accidentally got entangled in a fisherman’s net in San Miguel Bay last August 16.

According to a statement by the University of the Philippines Diliman College of Science, an autopsy found Calab’s stomach still full of undigested fish, indicating that she died suddenly and unexpectedly.

“Calab’s death is an unfortunate incident, but it has paved the way to learning more about these rare and beautiful creatures,” said Dr. Lemnuel Aragones, president of PMMSN and a professor at the Institute of Environmental Science and Meteorology at the UPD.

Irrawaddy dolphins (Orcaella brevirostris) are characterized by gray or dark-blue backs and pale bellies. They have a high tolerance to various levels of salinity, which enables them to live in areas where salty seawater and freshwater meet, such as in the mouths of rivers and bays.

^{Photo: BFAR V}

They are among the world’s most endangered dolphin species, indicated as critically endangered on the Red List of the International Union for Conservation of Nature and by the Department of Environment and Natural Resources (DENR).

This is the first time that an Irrawaddy dolphin was found on the Pacific or the eastern side of the Philippines. It was previously sighted in the western part, in Malampaya Sound, Palawan, and in the Iloilo-Guimaras Strait.

Experts have yet to understand how Irrawaddy dolphins found their way to these provinces. Aragones suggests that they might have been there since prehistoric times, before humans arrived in the archipelago and possibly even before humans existed, when environmental conditions were optimal for widespread migration.

“Basically, the populations have been there for a very long time, we just didn’t know to look for them,” he said. Despite needing air to breathe, dolphins generally spend as much as 95% of their lives underwater, enabling them to elude discovery."

Aragones said he is eager to know more about other possible marine mammal species in San Miguel Bay. He said Calab is proof that there is still so much to be discovered in the Philippines’ richly biodiverse waters.

He and his team of marine mammal scientists and local BFAR personnel are scheduled to visit the bay to hopefully find more Irrawaddy dolphins and study them in their natural habitat. —Nika Roque/JCB, GMA News