Cetaceans of Timor-Leste | Whales and Dolphins

Global Cetacean Hotspot

The coastal waters of Timor-Leste are a recognised global ‘whale hot spot’. Both, for the number and diversity of whale and dolphin species (or 'cetaceans') and also, their abundance. As such, at least 1/3 of all known species of cetaceans in the world can be found in Timor-Leste's waters. Some of these species are migratory, while others can be seen all year round.

One of the most common migratory whales passing through the waters of Timor-Leste is the pygmy blue whale (Balaenoptera musculus brevicauda) – known as ‘parawu ina’ (transl: 'blowing whale') by local fishermen. Each year, hundreds of pygmy blue whales pass through Timor-Leste waters on their extraordinary 10,000km annual seasonal migration – from their feeding grounds off southern Australia to their breeding and calving grounds in the Banda Sea (Indonesia). Migrating north through Timor-Leste waters (toward Indonesia) in June-August and returning south (toward Australia) in October-December.

With so many animals occurring so close to shore, Timor-Leste is possibly one of the best places in the world to watch and monitor Pygmy Blue Whales. (Photo Credit: Matthew Barbour).

Tagging studies by Australian researchers confirm that animals that are seen in Timor-Leste have likely come direct from feeding grounds in western and southern Australia (ie. Perth Canyon, Bonney Upwelling).

Large ‘super pods’ of large and small dolphin species (often containing hundreds of animals) – of up to 4-6 different species - are also a major, common feature of the ocean waters off Timor-Leste. And a strong indicator of the high-level of ocean productivity (ie. nutrients, food) in the region. In 2007, the first national-scale cetacean surveys conducted in Timor-Leste (funded by the Government of Timor-Leste) reported some of the highest levels of cetacean abundance ever recorded. In a single day of observations, we observed more than 1,000 individual animals and 10 species, over just 50km of coastline.

At least 24 species of cetaceans have now since been confirmed residing or passing through Timor-Leste’s waters. Among them, baleen whales, toothed whales, killer whales and ‘superpods’ of large and small dolphin species – including some of world’s largest and most threatened cetacean species. These include large, migratory Blue Whales, Bryde’s Whales, Sperm Whales, and also, several species of rare and poorly-known, beaked whales.Around the island of Atauro, 25km north of Dili, semi-resident populations of ‘Blackfish’ (Pilot Whales, Melon-headed Whales) can also be regularly found close to shore.

'Ocean Highways'

Timor-Leste’s geography, complex bathymetry and oceanography are all factors which contribute to the country’s global significance for cetaceans. The island of Timor lies between 2 narrow, ocean trenches (more than 3km deep) - the Ombai-Wetar and Timor Trough - which run along Timor’s northern and southern coast, respectively. Together, these 2 deep-water passages provide ideal migratory corridors or ‘ocean highways’ for cetaceans and other pelagic marine wildlife (eg. sharks, rays, turtles).

The island of Timor sits between 2 deep, narrow, ocean trenches - ideal ‘oceanic highways’ for cetaceans and other pelagic marine wildlife (Data Source: GEBCO 2014).

Importantly, these 2 deep-water passages represent 2 of the 3 major outlets of the Indonesian Throughflow (or ITF), the major current system connecting the waters of the Pacific Ocean to the Indian Ocean. Recent studies have estimated that more > 80% of the total flow of the ITF (ie. -12,400,000 m3s−1 ) passes through Timor’s 2 deep ocean passages – the largest flow of ocean water on the planet.

Significantly, the prevalence of these very deep waters close to Timor’s coast, also, provide conditions for regular, localised seasonal coastal upwellings. Driven by monsoonal winds, these upwellings result in high ocean productivity, bringing colder, nutrient-rich waters from the deep ocean to the surface – providing potential feeding grounds for both, resident and migrating species, particularly baleen whales.

The Ombai –Wetar Strait along the north coast of Timor is particularly narrow (35km wide), with very deep water close to shore - sometimes <100m offshore. With a large number of animals occurring so close to shore, we suggest that Timor-Leste is arguably one of the best and most accessible places in the world to view and monitor Pygmy Blue Whales and other cetaceans.

Monitoring Cetaceans

Whale watching and marine ecotourism hold great untapped economic potential for the Timor-Leste - a fragile, post-conflict, ‘developing’ country - both for established (and new) commercial dive operations and also, for local coastal communities.

With the potential for rapid growth of whale watching in Timor-Leste, there is a critical need for information and ongoing scientific research and monitoring of cetacean species - as well as support and cooperation among the diverse key stakeholders (researchers, government, NGOs, development partners and donors) - to support cetacean conservation and also, to ensure sustainable whale tourism.

Sitting in the direct pathway of the Indonesian Throughflow, at the north-eastern boundary of the Indian Ocean, we believe Timor-Leste is a great location to observe and monitor cetacean species – to better understand their biology, behaviour and movements, and also, their population status and health.

Since 2012, our ongoing cetacean surveys, our ‘citizen-science’ sightings program (with local dive tour operators) and also, community-based monitoring by eco-volunteers and local fishing communities, have now confirmed globally significant levels of cetacean abundance and diversity in the waters of Timor-Leste.

We invite you to join us ! Help us collect information - and improve our scientific knowledge and understanding of the incredible cetaceans of Timor-Leste !