Five dolphins died in Bais City, following a mass stranding in Bais Bay, Negros Oriental.
Authorities suspect the dolphins died from lung trauma caused by blasting sounds.
Bais City Veterinarian Dr. Melanie Pescadilla said Wednesday that necropsy results revealed lung lacerations in three of the four examined dolphins, consistent with injuries caused by intense underwater pressure or loud explosions.
“They died of drowning secondary to blast trauma,” Pescadilla said, noting that the lungs of dolphins have air spaces that make them vulnerable to pressure/impacts from blasts.
The dead dolphins, identified as pantropical spotted dolphins, were recovered over several days – three on Sunday, one on Monday – and the latest on Tuesday. Four were adult females, while one was a juvenile female.
One dolphin was not examined as it had to be buried immediately due to time constraints.
Authorities have yet to determine whether the lung injuries were caused by illegal dynamite fishing or other underwater activities producing loud blasts.
Pescadilla estimated the trauma to have occurred three to five days before the dolphins’ deaths, based on organ discoloration.
Residents first spotted about 17 dolphins in shallow waters off Barangay Luka in Tanjay City on Saturday. Locals and rescuers attempted to guide them back to deeper waters, but the pod eventually stranded in barangay Canlargo, Bais City, as the tide receded.
The Philippine Coast Guard reported no further sightings of stranded dolphins as of Wednesday, following efforts to guide the surviving ones back to the open sea.
Dr. Lemnuel Aragones, head of the Philippine Marine Mammal Stranding Network, and his research assistant Apple Amor provided virtual assistance during the necropsies.
Local police, Bantay Dagat (sea watch) volunteers, barangay officials, fishers, residents, and personnel from the Bureau of Fisheries & Aquatic Resources also assisted in the rescue and recovery efforts.
Dr. Pescadilla said they are still awaiting laboratory results for further confirmation of the cause of the dolphins’ death. (Judy F. Partlow/PNA)
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Photo Caption: Villagers from Bais City look over a dead dolphin, one of five dolphins that died after a mass stranding in Bais Bay last week. (Choy Gallarde photo)