Why Do Whales and Dolphins Frequently Strand in Indonesian Waters?

A recent incident in Rote Ndao Regency, East Nusa Tenggara, saw 55 short-finned pilot whales (Globicephala macrorhynchus) strand on the shores of Mbadokai Beach and Fuafuni Village. The event on Monday, March 9, 2026, resulted in the death of 21 individuals—4 calves and 17 adults—with the remaining whales being guided back into the sea. Achmad Sahri, a marine mammal expert from the National Research and Innovation Agency (BRIN), stated that such strandings are not uncommon. He explained that pilot whales are a species with very strong social bonds, typically forming communities of 50 to hundreds of individuals. When one individual experiences a problem, whether due to health, natural, or human factors, others tend to follow, leading to mass strandings. "Even when approaching coastal areas, they remain together until they strand. So, it's purely due to social bonds," stated the Senior Research Scientist on Thursday (27/8/26). Sahri noted that the short-finned pilot whale case exemplifies common causes for whale and dolphin strandings. Two main factors are identified: natural causes such as disease or old age, and anthropogenic factors stemming from human activities. These can occur individually or in combination, though further research, including medical dissection of the animals, is necessary. "Natural factors can also include solar storms, something that might be difficult to measure," he added. Anthropogenic causes include environmental degradation leading to pollution and changes in marine ecosystems, such as plastic waste. Coastal development and the use of underwater sonar in oil and gas exploration are also implicated. Whales and dolphins use sound for communication and navigation, and disruptions to these acoustic environments can disorient them. Indonesia, with its extensive coastline and rich marine biodiversity, frequently witnesses such events, highlighting the critical need for conservation efforts and responsible human interaction with marine life.