Richard Robinson slathers sun cream through his stubble and across his brow in a single motion, flops his cap onto his crown and pulls it taut by the brim. Standing on the cabin top of the boat, he whips a rope around his hips and throws a loose bowline to form a big loop.
“This is my favourite thing,” he says. “I live for it.”
Not riding on a rooftop, but what we’re about to do—point the bow at the razor horizon and strike a fine white line from the known into the unknown, from green water to blue water, from the place of coastal creatures to that wide, wild realm of Tangaroa.
“Let’s go,” he says, leaning back into the rope noose and hitching a pair of binoculars around his neck.
The diesel engine roars, throwing a ragged jet of white spume that propels us forward. The turbo whines, water hisses against the boat’s chines, and wavelets patter on the hull.
The sea is oily calm, like kerosene, and the air thick with humidity. To the east, huge cumulous clouds bale up on a tight-rope horizon. To the north and south it is clear, the sun creating a silvery path across the sea as if it was made of aluminium foil.
Keep travelling east from here and you’re unlikely to encounter a patch of dry earth until you reach South America, 9000 kilometres distant. Two thousand kilometres north are Tonga, Fiji and Samoa, a scattering of limestone rocks that interrupt a more or less unbroken line to the Bering Sea and the cold east wing of Russia. To the west, the coastal outpost of the Poor Knights Islands and the long, rich shore of the Tutukaka coast. To the south, the great embayment of the Hauraki Gulf, once an aquarium of coastal sea life, now heavily trafficked and fished.
To landlubbers, this space beyond New Zealand’s territorial limit is a featureless swathe of open sea, but to mariners, this is the edge of a vast prairie defined by abyssal plains, oceanic trenches, high submarine ridges and towering sea mounts. It’s the end of New Zealand as we know it, and the beginning of something else entirely, a liquid world ruled by strange currents and invisible waves.
“The whole subsurface is an unseen world. It’s easy not to think about it,” says NIWA oceanographer Joanne O’Callaghan. “But we care about the weather, and the oceans are in constant change along our coasts, too—this is like ocean weather.”
Balancing a laptop on her knees, she lifts the lid as though it’s a treasure chest. Inside, a dazzling, tie-dyed graphic of sinusoidal waves.
She tells me how internal tides are compressed by the continental shelf and propagate at the thermocline, then, sensing I’m out of my depth in the shallows, breaks it down. “An internal tide is a wave of pressure under the surface of the sea. When it reaches shallower water, it becomes amplified, and draws up chlorophyll from deeper water.”
Chlorophyll is the green stuff in plants, algae and phytoplankton—the base of the food web in ocean systems. Subsurface waves move plankton upward through as much as 60 metres, like an undersea escalator, closer to the things that feed on it. Saury, pilchards and other anchovy-like fish come with it, and they in turn are prey for larger fish such as kahawai and kingfish, and those species that migrate with the warm summer currents—tuna, sharks, dolphins, pseudorca and pilot whales.
Above the aggregation, small fluttering birds such as shearwaters, terns and gulls feed on the plankton and schooling fish. With aggregations that include toothed whales such as pseudorca and pilot whales, black petrels also join in, uplifting the particles of flesh strewn as fish are shredded.
It may be more helpful to think of these throngs as a single organism, rather than individual species—interdependent and mutually beneficial, but vulnerable to climate change and industry. Shifts in water temperature can move the blooms of phytoplankton by hundreds of kilometres. And fishing can collapse the whole order.
O’Callaghan pulls up a world map that is marbled with streams and patches of colour. Each corresponds to a site of these internal waves. The north-east coast of the North Island is painted tulip red.
“We don’t fully understand these subsurface waves,” she says. “We know they’re important, but there are a lot of questions about their generation and how the energy is mixed and used in the ocean.
“It’s where we fish, where we dive, but it’s also the waters we use for shipping and aquaculture. Understanding these systems will inform how we manage ecosystems, where we do things or where we don’t do things.”
Using Google Earth, a casual observer can see the pattern of these waves online, yet we know little about what happens underneath the expressions on the surface.
A thousand little geysers spring from the sea around me, the breath of life rendered visible in spray erupting from the rounded mantles of whales and dolphins.
We happened upon them, a click beyond the territorial limit of New Zealand, idling on the surface like a crowd mingling at an event that has either ended or is yet to begin. We shut down the boat a distance off the group and loiter, in a manner not unlike the whales, and gradually their meanderings coincide with our drift, until we are surrounded by their breath—short puffs of vapour from pelagic bottlenose dolphins, plumes of gas from false killer whales, and the launch of a salvo of mortar shells that announces the arrival of pilot whales.
Hundreds of animals wheel in slow rotation around us, pull up abeam, spy-hop a little to get a good eyeful of the vessel, then ease beneath the surface.
There isn’t a speck of land to be seen, just a 360-degree rim of blue. Like the whales, the waves lack any perceptible direction, lifting into shiny peaks and dipping into dark, round valleys joined by sharp crescents. The water licks at the sides of the hull and slaps under the chines, but otherwise there is little sound, save the puffs of the whales, vaping.
I slip on fins and gently slide in, the cold water gripping my chest and tracing frosty rivers down my back. As my head dips under the waves, everything changes. The overcast palette of steely grey becomes peacock blue, and my head fills with a chorus that surges up and down the register, both madly shrill and strangely symphonic. The songs seem to come from all directions, like being wrapped in a sheet of sound.
I am five metres underwater now, the surface a glossy, undulating sheet of glass above me. There are whales and dolphins on all sides, from an arm’s length away to the faint point in the distance where the shapes of the animals become indistinguishable from the pearly blue water.
The pelagic bottlenose dolphins are darker in tone than their brethren along our coasts, and significantly bigger—like an American muscle car might appear next to a Honda. But they are dwarfed by the shapely bodywork of the lithe pseudorca, which are half as big again—a steely blue-grey to the bottlenose’s gunmetal flanks.
Next to these leviathans I feel like an inelegant, bony contraption—all elbows and knees, churning flippers and flailing arms, more like a construction drawing than a finished product. They are all longer than I am tall, and many times my weight: sleek tubes of muscle that turn by bending their whole form, and surge forward with a light, positive press on the tail.
I stop pedalling for a moment and hang in the water column, head up, fins down, like a dripping suit on a washing line. I am suspended in blue space, 350 metres off the seafloor, surrounded by sound and whales.
A lumbering herd materialises, with sharply hooked pectoral fins and massive jet-black bodies. Pilot whales, torpedo-like in form and performance, with a brilliant white gang patch across their backs—about 30 of them, that I can count, rising and falling, their backs gracefully hinging in sinuous curves.
Then they depart, like ghosts slipping behind a curtain. I become aware of the sharp, dark lines of a dusky shark a few metres beneath me, snapping back and forth on an erratic course to find a meal.
Stars are forming in my vision, my lungs burn. I kick and crawl and reach for the daylight. Bursting through the surface, I suck in a breath that splutters and gargles.
My skin is slick with salt water, my lungs full again. There’s Richie, chortling through his regulator, and around us an expanse of waves and fins and tiny geysers—two souls adrift in a sea of souls, and the reassuring sight of the vessel that has brought us here, heaving in the sea 60 metres away.
Richie has a card full of photos, I have a head full of new ideas, and new questions. Like, what are they doing here? What is there, 350 metres below us, that attracts several hundred whales and dolphins to this same spot?
Jochen Zaeschmar is speaking to me from his car in Opua, over a fragile Skype connection that shimmers and warbles according to the breeze, or passing clouds.
Zaeschmar is originally from Bremen, an ancient port city on the north coast of Germany. He travelled to New Zealand in 1997 and got stuck, running a charter business from his yacht.
Every day, he would head out to sea in the Bay of Islands, and occasionally come across whales and dolphins. Sometimes together. After years of watching, he noticed that every sighting of pseudorca—also known as false killer whales—was in the company of bottlenose dolphins, and he began to perceive some unusual behaviour. The comparatively larger pseudorca would not only roam with the more numerous bottlenose dolphins, but they would feed with them, too. Sometimes they would even appear to share food—one of the fewknown examples of one species sharing food with another.
Zaeschmar began taking notes. Turns out, he was the only one taking notes.
Pseudorca are a species with too few lovers in New Zealand—no scientific paper had ever been published about our pseudorca, and the only written records were from strandings. It was as though they didn’t exist.
A couple of years and many notebooks later, Zaeschmar decided to correct the record. Despite the lack of any scientific qualification, he began a master’s degree in marine science at Massey University. It was, he admits, “a bit of a learning curve”. Especially because he chose to focus on the little-known relationship between pseudorca and bottlenose dolphins, something that no one had studied before.
Like… why? Why does a pod of hundreds of dolphins need or tolerate the company of a small pod of whales? And why do the whales want to hang out with their smaller, slower cousins?
They are largely preying on the same things, says Zaeschmar, but there are some notable exceptions.
“False killer whales are fast enough and large enough to take big yellowfin tuna, and they’ll share it among their conspecifics, and also with the dolphins,” he says. “But whether the false killer whales are actually sharing their food or whether the bottlenose are just scavenging it from them is a matter of interpretation.”
While food-sharing may be difficult to assess, another reason for the association may be more sinister. Bottlenose dolphins may keep company with the larger, tougher pseudorca to receive some protection from orca—the nine-metre, five-tonne super-dolphins have a reputation for bullying and killing both species.
In return, pseudorca may benefit from the ‘dilution effect’—more potential victims means a lower likelihood of becoming a victim. And, Zaeschmar notes, pseudorca and bottlenose dolphins have different echolocation skills that may complement each other, allowing for more efficient hunting of prey, or different prey, than they may be able to capture on their own.
“Mutualism, parasitism, commensalism… it’s hard to test the relationship scientifically, and the benefits may not be equally distributed. Are they together because it’s safer?” he says, echoing back my question. “It’s hard to isolate just one factor; it seems to be a win-win situation.”
What is more certain is the uncertainty around the population.
After analysis of thousands of dorsal fin photographs, Zaeschmar discovered that he was seeing the same individuals over and over again, which meant two things.
First, there are a small number of these whales around the North Island’s north-east, possibly as few as 200 in two distinct groups, one venturing inshore during summer months, the other remaining farther out. (The latter group can be distinguished by very recent scars from cookie-cutter sharks—a deep-water species that carves biscuit-sized discs of flesh from the flanks of the whales.)
Secondly, they either constantly return to New Zealand waters or perhaps never leave at all, which raises the prospect that this is a small and vulnerable group of residents that neither science nor the authorities know much about.
New Zealand’s pseudorca are, at best, ‘data deficient’. At worst, they could already be locally endangered, a fact that could trigger a very familiar scramble to understand a species and mitigate its perilous decline before it’s too late.
Rochelle Constantine sweeps aside a plastic bag of little bottles to make room on her desk.
“Bits of dolphin,” she says apologetically.
In each vial a tiny sliver of blubber, like a fingernail clipping, floats in alcohol. They are samples of Hector’s and Māui dolphins sent from Massey University pathologists for analysis, she tells me. Extract and sequence the DNA, combine it with findings from other studies, and you’ve got the map of an entire species—data critical to their management and survival.
“There are still fewer than 100 Māui dolphins, but we think the population may be slowly increasing now,” she says. “Some of the immediate threats are gone. That house is no longer on fire.
“It’s nice to think that conservation problems can be solved. They’re still in serious trouble, but we need to celebrate the small successes we’ve had.”
This is the power of human industry. We can push another species right to the edge, then, applying a different ideology, a bit of science and some well-structured solutions, we can turn that legacy around.
But there are some big differences between protecting our coast-loving Māui dolphins and the amorphous target of understanding and making room for a dozen species bound together in an interactive web of relationships—from plankton to pilchards to whales. One difference is data. We’ve little idea how common these aggregations are, whether all players are always present, and what might be threatening them.
“There’s no catch data on small schooling fish, but it’s such a critical link for transferring energy up the food chain,” say Constantine. “There are trawlers going out fishing and we’ve no idea what is being caught. It’s not insubstantial.”
Likewise, fisheries pose a threat to large megafauna—they have high energy demands, and often coincide with commercial species such as tuna and squid. (Pseudorca, in particular, have a reputation for taking tuna right from the hooks of longliners. Some foreign fishers have started shooting at them.)
Finding a balance that is sustainable, not only for the target species but also for those species that rely on them, is complex and contested—particularly offshore, where there is little data on which to base decisions. But there are larger forces at work, too.
The ocean is a mobile and surprising system, responding to a cocktail of conditions that occur at the intersection of temperature gradients, weather events and the collision of ocean currents.
Constantine raps something into Google and swivels her laptop towards me. There, in the loops and flourishes of god-sized handwriting across the Tasman Sea, is a heat map of currents and temperature anomaly data. The seas off Tasmania, she says, baked in a heatwave 3ºC above normal last summer, and tendrils of that anomaly reach out like feathers across the Tasman to New Zealand. The waters of Otago have already increased by 1ºC in the past 60 years, she says.
It’s all coming our way—the oceans are warming and acidifying, fishing effort in the high seas is intensifying, and what that means for those creatures beyond our shores is anyone’s guess.
We are beginning to understand why they are here, and some of the factors that influence their distribution and lifecycles. But we don’t know how many there are, where they travel, what threatens their existence and to what extent.
We don’t know nearly enough to protect this vast blue ecosystem at our edges, or even if it needs active protection.
How do we value this place? Do we pull it closer or hold it further away?
The truth is, this is an ecosystem too remote for many of us to care about, but too close to escape our influence. How we protect it will require a new vision of our relationship with the ocean that carried most of us here. Rather than valuing only what comes out of it, we may need to consider all that remains within.