In December 2008, scientists reported one of the highest concentrations of whales and dolphins ever recorded, in the deep waters off Timor-Leste’s north coast. The survey, led by marine ecologist Karen Edyvane for the Timor-Leste government, counted more than 1,000 animals in a single day, and later research has confirmed the Ombai-Wetar Strait as a global hotspot for cetaceans.
What the 2008 survey found
The boat survey was carried out with Northern Territory government scientists, Timor-Leste’s fisheries ministry and the Australian Institute of Marine Science, following an aerial survey of the coast. The full results are in the 2009 marine megafauna survey report. Along a 50 km stretch of coast, the team counted more than 1,000 whales and dolphins in eight pods in one day. Species included blue whales, beaked whales, short-finned pilot whales, melon-headed whales and six species of dolphins.
“We were all amazed to see such an abundance, diversity and density of cetaceans,” Edyvane told reporters. The scientists linked the numbers to the deep water of the Ombai and Wetar straits, a migration route between the Pacific and Indian Oceans.
What later research added
Edyvane, now at the Australian National University, has continued surveys in Timor-Leste. Work from 2016 to 2023 recorded at least 21 whale and dolphin species and confirmed a yearly migration of pygmy blue whales through the Ombai-Wetar Strait; her programme has logged more than 2,700 blue whale sightings since 2014. In 2020 the strait was named a Mission Blue Hope Spot.
Seeing whales and dolphins
Whale-watching trips leave from Dili and Atauro Island. The main whale season is October to December; dolphins can be seen year-round. Sightings are never guaranteed. See our dolphins and whales guide, and for the story in film, the Ombai-Wetar Strait: Timor-Leste’s whale superhighway.