DAVAO CITY – The carcass of a six-foot male spinner dolphin with ruptured eardrums was found on the shore of Punta Dumalag in Barangay Matina Aplaya here on Wednesday, August 2. American marine biologist Darrel Blatchley said in a social media post that the result of the necropsy did not conclusively reveal the dolphin's cause of death. He said its eardrums appeared to have ruptured “due to blood pooling on both sides.” Blatchley said no traces of food were found on the intestines of the 40-kilo dolphin. “Ruptured eardrums affect the dolphin’s hunting capacity as it’s their sonar or echolocation system,” he said. He said the DNA of the marine creature has been saved for study while its bones will be prepared for display at his D’ Bone Collector Museum here. “Number 76 for the museum, 61 (of them) due to man in 15 years,” he wrote. In a statement, environmental group Ecoteneo said that the “Davao Gulf is home to at least 15 species of marine mammals.” “Activities that affect their hearing are crucial and can cause their death because they travel through echolocation,” it said. Spinner dolphins weigh 100 to 165 pounds and measure 4.25 to 6.89 feet and can live over 20 years, according to Greenpeace.org. The International Whaling Commission said that spinner dolphins are found in the Pacific, Atlantic, and Indian Oceans, as well as the Persian Gulf and Red Sea. The Spinner dolphin is listed as least concern in the IUCN Red List of Threatened Species in 2018.