Blue Whales of the Banda Sea and Forgotten Islands

Blue Whales of the Banda Sea and Forgotten Islands

WORDS & PICTURES Simon Mustoe


There are a handful of places where the history of oceans, life on Earth and Western civilisation collide in spectacular form; where networks that stabilise weather systems, create fisheries, our economy, determine our farming seasons, regulate climate and fuel global food production, can be appreciated through what you observe in plain sight. One of these is the Banda Sea. 

The ocean supplies ingredients for all life on Earth. Gravitational forces agitate this viscous, three-dimensional world into a Herculean swirling mass, the energy from which, stirs food-chain reactions that support unfathomable densities and diversity of creatures. 

The oceans’ animals moderate the chaos. Millions of years of evolution have created stable ecosystems where wildlife, from the smallest plankton to the greatest whales, act together so planet-scale energy is released in just the right quantity and timing for stability. 



Barrel Sponges like this grow at a rate of just 1.5cm a year. The oldest in the world are estimated to be over 2,300 years of age.   

Places like the Banda Sea have lent themselves to the development of our civilisation. We are both a cause and effect of what exists there today.  

Located between northern Australia and Sulawesi, a rim of volcanic islands skirt the Banda Sea over 7,000 metres deep in places, creating a channel where the Pacific empties into the Indian Ocean. Some of the world’s greatest forces coincide here to create conditions like nowhere else.  

The first of these is the Indonesian Through Flow, a current equivalent to 15 million tonnes of water a second, over ten times the volume of all the world’s rivers. Gravity and the planet’s rotation trap the ocean against Earth’s crust and a phenomenon known as Coriolis (the pattern of liquid movement over a rotating sphere) sets off currents north and south of the equator, where they become a series of interlocking, circular-motion eddies.

This transfer of planetary energy into motion creates all our wind and weather. It’s shaped our agriculture, fisheries and has long fed a growing human population.

Prompted by Coriolis, the world’s warm shallow currents then twist, bend and bounce off continental land masses, a perpetual motion driven by evaporation.

Ocean water rises and falls with changes in density, salinity and temperature. Cool waters surface off Alaska and heat up as they flow south to equatorial seas before crossing the Pacific and passing into Indonesia. A full circulation of the world’s ocean water takes about a thousand years.

When the Through Flow first strikes, it hits Raja Ampat, an archipelago of islands supporting 75% of the world’s coral species. For the most part though, it flows along the top of Halmahera and then down the west coast of Sulawesi before tracking east along the Sumba chain. 

By the time it has reached Banda, this buoyant 150m deep layer of water has been stripped bare of nutrients. It’s crystal clear, bright blue and devoid of life.   

But here it meets a mass of nutrient-rich water from below, lifted by a phenomenal natural force, which strengthens in the south east monsoon. 

Driven by warming of the Asian continent and thermals over the Himalayas, trade winds are sucked in from the south east between June and August. In a small handful of locations world wide, where wind blows parallel to a lengthy coastline and there is deep ocean nearby, frigid abyssal waters can well-up carrying nutrients back to the surface. 

Sandwiched deep underwater between these two massive layers plankton become concentrated at unimaginable densities. For just a few months of the year, fuelled by nutrients from the deep and squeezed like a glass ceiling, against the warm Through Flow from above, the Banda Sea plays host to one of our ocean’s greatest, albeit hidden, wildlife events.   


 The tail of a Blue Whale can be 7m across. When deep-diving, they throw their flukes vertical and descend rapidly to the food layer. 

The story of this remarkable region is made sensational by the presence of the largest animal that ever lived. The evolutionary origin of Blue Whales, like most wildlife, can be traced back millions of years and their existence here is nothing short of serendipity. Humans and wildlife occur  because of the roles we act out  inside a vast physical, chemical and biological theatre.

One of Earth’s greatest mysteries is how populations of any species persist so long given the interdependency of so many seemingly random factors on their existence let alone survival.

Like any great mystery novel it doesn’t stop with a single character. The ecology of the Banda Sea’s Blue Whales is one chapter in a chronicle of all life on Earth with a supporting cast that includes the biggest planetary processes to the smallest creatures. These silvery leviathans exist in a realm we can only imagine and despite the best science detective work, their world is something we are only just beginning to understand.

The first published description of a Blue Whale was by Robert Sibbald in 1694, long after the Dutch and Portuguese started fighting over the Banda Islands and the species wasn’t described formally by Linnaeus until 1758.  Until then, Blue Whales were mythologised.

European crewmen, press-ganged into a life at sea, could reach Banda during the south east monsoon, when it’s one of the world’s most treacherous seaways. Trade winds parade across its several hundred mile reach, stirring ocean swells that still thwart transportation to the islands by ferry for six months of the year. It’s little wonder sailors would return with stories of sea monsters.

In our brief rise as a species on Earth we’ve capitalised on the Banda Sea’s services without knowing it at all.   

Instead, the first Europeans to visit were attracted by its tangible riches. The region is famous for its volcanic islands and deep fertile soils, wealthy in spices.

By the 1600s, the Dutch had ousted the Portuguese and colonised nine of the ten Banda islands, setting off a bloody history that would see most of the indigenous population slaughtered and replaced by slaves from Java. 


A Dutch cannon from the 1600s, pointing between ramparts on the pentagonal fortress of Banda Neira. 

For two hundred years, the islands’ spice - Nutmeg in particular -  were fiercely contested. 

The Banda Sea became a source of European wealth and economies were built on the trade of these precious commodities, that preserved food and gave it rich flavour.   

Worth more than gold and attracting a 16,000% markup in Europe, the Dutch East India trade company plied the world’s oceans. By the late 1600s, the Dutch had a monopoly on world trade, having secured the island of Run from the British in return for New Holland (that became New York) and securing their control for another 120 years. 



Blue Whales are constantly attacked by cookie-cutter sharks. Patterns of bites, including a fresh one on this whale, are what help conservationists tell animals apart. 

For the whales it was a time when whaling was done by indigenous whalers only. As Europe’s wealth and technology grew, people sought more and more ways to exploit the oceans. Sperm Whales began to be harvested but not until the mid 20th century, did Russian mechanised whaling ships start hunting southern Indian Ocean Blue Whales. 

A genetically isolated and svelte tropical population of Blue Whales split off from their larger southern ocean counterparts about 20,000 years ago to migrate each year, as they still do today, several thousand kilometres between the south coast of Australia and the Banda Sea. 

In the 1600s, their numbers would have almost certainly been greater. An incomplete record of whaling suggests over 12,000 animals were taken in the southern Indian Ocean. Where it’s common to see ten animals foraging now, perhaps there were once dozens.   

Watch these animals for a while and you begin to get a sense of their power and influence on our environment. 

Marine fish, whales and dolphins ‘stir’ the ocean, it’s thought, as much as all tides and wind combined (about a third of all ocean mixing) and this is greatly significant for global climate regulation.

As much as 15-20% of carbon ends up sinking to the seafloor. Fifty to 80% is used up along the way: that is, consumed by animals that assimilate nutrients before expelling a portion again as waste. It’s not the existence of nutrients in the ocean that creates life, it’s the rate at which it is absorbed, expelled and reabsorbed. It’s the cycles of living and death, not life itself, that drives the Earth.




The island of Suanggi or 'Little Manuk' has hundreds of seabirds breeding on it. It's just north of Banda Neira and is surrounded by spectacular coral reef. 

Marine animals trade nutrients inside their own economy. In fact, measuring nutrients in a natural system is difficult, because they are almost immediately absorbed. It’s the same as if we started leaving sums of money lying conspicuously in public open spaces. We’d expect them to be fairly quickly absorbed too!

Seabirds pick the scraps from schooling tuna, whales defecate iron back into the system to be immediately consumed by algae. Iron is strongly limited in the ocean surface but is a major electron carrier and catalyst for photosynthesis. More iron means more carbon uptake, lower atmospheric temperatures and greater productivity for global fisheries. 

There are so many connections we can’t possibly understand them all but seeing a relatively intact ecosystem is awe-inspiring. This is a place that has built up over millions of years, unaffected by ice-ages and where deep nutrients, thrown aloft to break clear of the Through Flow’s glass ceiling, become available for sea life to thrive.

Blue Whale populations in this area were less affected by whaling than in the southern ocean, where almost 98% of whales (almost 350,000 animals) were removed. The fact Blue Whales deep-feed on copepods, which have little direct economic benefit to us, may be the reason why they’ve persisted through a period of otherwise unprecedented exploitation of the Banda Sea’s bounty. 

Since Indonesia independence in 1945, tuna have been fished relentlessly to the point that recently, the stocks were considered ‘fully exploited’.   
Indonesia’s fisheries Minister Susi Pudjiastuti has recently overseen the high profile destruction of over 200 foreign-flagged fishing boats that remained fishing illegally in the region. A $4 billion industry collapsed and in ten years 800,000 local households, who had earned from fishing, lost their livelihoods.  
Today you won’t see a trawler in the Banda Sea but neither will you see large schools of tuna or as many hammerhead sharks as their used to be (some say up to 600 animals a night were caught by some vessels). 

It’s becomes no surprise that loss of human livelihood cascades off the effects of change when such volumes of large animals are taken from the environment. The effects are felt far away. 

In the remote southern Banda Sea is Manuk, a smouldering 3,000, high volcano that emerges 270 metres above the ocean. This isolated cone is one of six seabird breeding islands left in Indonesia. Brown Booby chicks rest patiently among abrasive basalt rocks crumbling in the overhead sun while their parents forage at sea. Red-footed Boobies and Greater Frigatebirds nest in trees on the precipitous slopes and rats parade on the ground scavenging on fig fruits, awaiting the next crop of young seabirds to eat.  


Frigatebirds have the lowest wing-loading of any bird on Earth. They can soar vast distances but return to the same colony to breed year after year. They drive nutrient processes across vast areas of tropical ocean. 

Only one of these ‘small Manuk’ near Banda Neira, is rat free. Numbers of seabirds have apparently been declining for 60 years, maybe as a result of rats, but its also likely because tuna no longer occur in an abundance high enough to force small fish (the birds’ primary food) to within beak-strike of the surface. Where Blue Whales lift nutrients skyward, food is swept on smaller currents; tuna excite fish to the surface and seabirds ration this, depositing the byproducts over the ocean and onto the nearby islands where the nutrient washes back onto fringing coral reefs and sea snakes thrive in huge numbers (which only happens on a couple of islands). Everything is connected.     




A Banded Sea Krait's tail is adapted for swimming. Two species live around these islands and come up on land to breed. 

Seabirds are resilient to natural fluctuations in ocean conditions but being long-lived, it can be many decades before the symptoms of failed chick-rearing start to show themselves at the population level.

So several thousand 30-tonne animals feeding continuously day after day are a relic of Banda’s once pristine natural history. They offer a glimpse into the sheer energy contained inside the sea’s boundaries. Still today, these whales undoubtedly have a huge role to play in our climate and may even be essential to the recovery of the region’s fisheries. They are worthy of unmitigated conservation. Today maybe as few as 700 animals survive but it’s not uncommon to see mothers with calves in tow, which shows some hope they are recovering from the shadowy days of commercial whaling. 

Diving and surfacing more or less on the spot, Blue Whales emerge with a mighty blast from twin blow-holes, clearing moisture from their nostrils before taking the first of a dozen deep breaths. They are indefatigable foragers, with unstoppable inertia and sleek hydrodynamics.

Even in a choppy sea, the muscular driving upbeat of their 6m wide tail, leaves a surface imprint like mercury, as they power their way to resurface 10 seconds later for another breath. 


A Blue Whale surfaces to blow in the Banda Sea

Eighty percent of their life or more is spent underwater feeding. The precious two and a half minutes in our atmosphere, is time enough to expel toxic gases from the blood and reinvigorate their internal life support with oxygen.

For the next strenuous eight minutes, they will perform ballet-like lunges, twisting and cascading up and down through clouds of invisible plankton. Each mouthful can be as large as their own body and contain up to two million calories. Their huge tongue, pressed against the roof of their mouth, squeezes water out through baleen plates before the salty seafood soup is swallowed.  

There is good evidence in the Banda Sea they are lunging through swarms of copepods, a tiny crustacean smaller than krill, with an energy content ten times greater. Densities of copepods at 4,000 per cubic metre, have been recorded here, far greater than even in the Antarctic.

Observe these animals for a while and you realise they are a big cog in a massive machine. We may think of wildlife as species to be simply protected or exploited but all animals, including us, are part of processes. When we begin to understand that, we not only have greater respect for them but start to see how we are also connected. 

These days, the outline of ‘pirate’ ships still cut an ominous shape on the horizon. Traditional twin-masted Pinisi schooners were plying the world’s oceans long before Europeans discovered spice. Today, vessels like PINDITO, take tourists on altogether more demure experiences. 

Once the purview of adventurers, you can fly to this destination in a day, discovering what would  have taken Darwin or Wallace, many months or years.

Nothing you read about the Banda Sea ought to prepare you for the sheer scale of this landscape.

If your preconception is merely a list of things to see, rather than understand, you can easily be disappointed and miss the chance to feel the mightiness of this place.   



A local fishermen in a dugout canoe has travelled 100 miles to be here and fish beneath this massive volcano. 

There is a scale to the Banda Sea like few locations on Earth: a scale that is hard for humans to comprehend. Diving or snorkelling over the pinnacles of volcanoes in the middle of a vast ocean, some of the deepest in the world, where the largest animal that ever lived roams is mystery enough to make this place enthralling.   

Turning fact into knowledge and experience into emotion is the wisdom that, for those of us who look at wildlife differently, will move us to tears and create impressions that last longer than any photographic negative has faded or digital storage device has been lost or corrupted. 

In our quest to conquer our aspirations to travel, we can forget the world - especially its oceans - remain as much a mystery as they once did and there is still much to be learned for those willing to find a new way to see. 

It is a privilege to visit the Banda Sea, to be offered a rare glimpse into the way this works and discover a profound insight into our actuality as human beings.  



Undersea, even the coral formations are mountainous.