MANILA — Sightings of dolphins and whales in a Philippine strait long considered an important waterway for the marine mammals have plummeted over the past two decades, with human activity in the area a likely factor, researchers say.
The latest survey of the Tañon Strait, a 161-kilometer (100-mile) narrow body of water between the central Philippine islands of Negros and Cebu, was carried out last year. It found fewer cetaceans, in smaller groups, than surveys conducted in the area since 1999.
https://news.mongabay.com/2020/01/key-cetacean-site-in-philippines-sees-drop-in-dolphin-whale-sightings/