BULELENG, DEWATA.NEWS – A short video showing a sperm whale (Physeter macrocephalus) surfacing in the waters off North Bali went viral on Monday, 8 December 2025. The ten-second clip captures the large marine mammal rising to the surface, lifting its tail, and diving back into the sea. The moment was recorded by local fishermen in Pemuteran Village, Gerokgak District, Buleleng Regency.
According to Gede Iwan Setiabudi, a marine science lecturer at Universitas Pendidikan Ganesha (Undiksha), sightings of sperm whales in North Bali are not indicative of a consistent migration path.
“The northern waters of Bali are enclosed and only open from the east. It is very likely that these whales are simply passing through, not using this as a permanent migration route,” Iwan explained on Monday.
He noted that established sperm whale migration patterns are more commonly observed in the Sawu Sea, Sulawesi waters, Maluku, and Papua, regions where movements can be recorded more regularly throughout the year.
“In North Bali, their appearances are unpredictable in both time and location. This is not a migration corridor; they may be following specific hydro-oceanographic patterns or sea currents that occasionally lead them here,” he said.
This is not the first time whales have been spotted in the area. Marine tourism operators in Pemuteran and West Bali National Park have reported occasional sightings, though these remain infrequent and irregular.
Iwan said such random appearances can be triggered by environmental factors. “They may be affected by underwater sonar disturbances, extreme temperature changes, or rough weather. It is storm season now, so the whale may have become separated from its group,” he added.
Sperm whales are social animals that live in structured groups. A whale seen alone, Iwan noted, can suggest it is lost or experiencing a specific physical condition.
From the video, Iwan confirmed that the animal displayed characteristics of an adult sperm whale. “The high tail lift before diving is a fluke-up dive, a typical movement performed before a deep dive,” he explained.
He also described the tail features visible in the footage: a broad, triangular shape, a deep central notch, and a dark color with a straight trailing edge, traits consistent with an adult sperm whale.
“Before diving, the whale also appeared to be logging, or floating calmly for about two seconds to breathe. This is standard behavior before descending to deeper waters to hunt,” he said.