The war on koi
Invasive koi carp now writhe through wetlands from Auckland to Marlborough, displacing native species and destroying freshwater habitats. For 25 years, bowhunters in Waikato have ministered their own brand of pest control, the World Koi Carp Classic, resulting in prizes, and 70 tonnes of puréed fish.
On October 29, 1988, Dave Gousmett travelled south from Auckland to the Whangamarino wetlands, north of Huntly. He’d heard rumours of huge golden fish having infiltrated the area. An avid bowhunter, he thought he might have a go at shooting one. The day was overcast and still, with water levels high enough to flood parts of the Waikato. It was a perfect day for shooting fish.
Gousmett had a day’s tour plotted out on advice of DOC staff. The second spot on his list was a submerged paddock on Falls Rd. It was here that he saw his first koi carp. Pretty soon he saw his second, then his third. There were dozens, bright-orange flecked with black, basking in shallow water.
Koi carp are thought to have been naturalised after fish from a garden pond were liberated into a waterway near Te Awamutu in the 1960s. For 20 years, they spread and bred, first coming to DOC’s attention in 1983, with Gousmett and the bowhunters following a few years later. But it wasn’t until the 1990s that the true extent of the problem was revealed.
Koi carp are now widespread in Auckland and Waikato and are spreading into Northland. They have been found in Whanganui, Hawke’s Bay and Wellington, and illegally released in the Nelson/ Marlborough region too.
All morning, Gousmett fired and came up empty, the alloy target arrows bouncing off or breaking in the strong, thick-skinned fish. Finally, he came upon a large patch, and fired once more. Another miss, and the fish were spooked, fleeing up a stream. He took aim at the last fish in the school, fired—and hit. Three kilos of inedible ornamental koi carp was on the line, and a strange passion was lit among a small but devoted bunch of archers.
Gousmett has since made more than 450 trips down from Auckland to the Waikato wetlands to hunt the fish. He and other bowhunters love koi. “If you’re a bowhunter, you like shooting your bow,” he says.
With koi, you get to do that a lot. When hunting deer, you might fire two or three shots in a week. A good bowhunter can hit more than 100 fish in a single day.
While koi were still rare in the late ‘80s, in subsequent decades they’ve thrived spectacularly.
I stand alongside a small stream adjacent to Lake Waikare, near Huntly, and watch koi constantly for half an hour. They breach and wriggle muscularly upstream through the rapids. It’s a spectacular sight, all the more so for the incongruity it represents—these fish are bright orange and yellow, striped and spotted and quite manifestly not from around here. I’ve seen them before, lazily meandering through ponds at fancy hotels. There they made sense. Here their presence is unnerving.
This invasive species—‘pest fish’, to those who work with them—is now the subject of intense efforts to control its spread, to purge it from conservation areas and give aquatic life a chance to revitalise there, away from the koi’s suffocating presence.
The bowhunters—for their part—have expanded their hunt with the expanding range and population of their quarry, and decided to make a competition of it. The grandly titled World Koi Carp Classic (WKCC) was first run two years after Gousmett shot his first fish. The tournament has now become New Zealand’s biggest bow-fishing event, and one of our nation’s most bloody and bizarre sporting contests.
The tournament is now in its 25th year, and the aim has remained the same: to shoot and kill as many koi as possible. A relatively small number of bowhunters gather at Huntly each year and go mad with bows and arrows. Together they’ve claimed more than 25,000 koi. More than 70 tonnes of coarse fish. There are prizes for the biggest and smallest in various colours, and two categories for the benefit of the bloodthirsty: Team Weight, for heaviest cumulative catch, and Most Carp, for the sharpest-shooting individual.
On the first weekend of November, men gathered from around the country to take to the region’s waterways with bows and arrows. While the number of participants was down somewhat on previous years when more than 100 took part, there were still more than 50 archers roaming the lakes and streams of the Waikato in boats and on foot, shooting fish.
Photographer Richie Robinson and I arranged to meet at the tournament’s headquarters, the former Huntly railway station alongside Lake Puketirini, a former opencast mine turned into one of the region’s few pristine bodies of water. We arrived at 8am and found not a soul. Bowhunters are solitary and competitive sorts—most had been up at dawn and off alone or in teams to prime locations they guard jealously.
Around the far edge of the lake we met up with the last to leave. Logan Cubitt and Jon Howard were gazing out to the water and prepping their gear. They make an odd pair. Cubitt is tall and in his late 20s. He got into bowfishing mainly as a “piss trip” with some mates. They drifted away, but bowfishing stayed with him. Howard is 14, a student at Tauranga Boys’ College, and here with his father. He’s solidly built and ghostly pale, only six months into archery but already possessed of his first big-game badge: ‘daytime wallaby’. They agree to let the photographer and me tag along for the morning.
We drive north before heading back across the Waikato River near Glen Murray, then make a left through what looks like a private farm gate. The track deteriorates until it is barely a contour in the grass, shadowing a small tributary of the Waikato which flows from the north-western tip of Lake Whangape.
There’s a rocky weir running along the boundary of the river and lake. The trio walk across, Cubitt striding confidently, pulling ahead, while Howard and his father linger gingerly. Towards the far edge, Cubitt pauses. In one smooth motion he draws his bow, aims and shoots. There’s a flash of white, then a mighty stir.
He’s nailed a five-kilogram white koi mere minutes into the morning. It’s not long after 9am on a perfect day in the Waikato, and the omens look good for these young archers, and very bad for carp.
Then, for a long time, there’s nothing. Howard wanders down the riverbank, firing dozens of times, always missing. He’s shooting too often, and from too far off. Cubitt is far more circumspect. He has a very particular walking style: feet very flat, with weight on his heels. Long, slow, deliberate steps.
Koi have a bone in their skulls that is extremely sensitive to vibrations, hence they spook easily at human footfall. But for all his patience and experience, Cubitt’s results are as poor as Howard’s.
After an excruciating hour, Howard finally finds flesh, winging a rather miserable little goldfish—another invasive species endemic to the area. The pair give up, though Cubitt picks up another good-sized orange koi on his return journey. He tows his fish behind him on a rope hooked through gills to mouth. They trail over rock and grass and arrive grazed and dirty, with none of the reverence often reserved for edible fish. He smokes a couple of Dunhill blues while they weigh their meagre haul. Cubitt’s are both in the five-kilogram range, while Howard’s goldfish is a little under a kilo.
It flops around forlornly, and Howard bashes it with a club. A little too enthusiastically.
“Jon! You’re going to reduce the weight of it if you take its head off,” admonishes his father.
“I’m just going to squeeze the guts out,” says Howard. He’s keen to take out the ‘smallest’ category. Dad’s not impressed. “You’ll win fairly or not at all,” he says sternly.
It’s a disappointing start to the weekend. We’d heard about 25-kilogram grass carp, about water teeming with fish, about spawning events that turned the water bright orange. We’d been told about Kevin Low, a tournament legend with stamina to match his aim. He would run along the lakeshore, shooting as he went, leaving his partner to pick up the catch. Many of the WKCC’s meticulous records for size, volume and total weight are owned by him or his teams. Low won Most Carp eight years in a row; his record weekend haul was 331 in 2006, when his team brought in a monumental 869 kilograms of carp—more than one per cent of all fish shot in the history of the competition. By one team, in one weekend.
While bowhunting represents one method of control, science has presented another; a $250,000 project called ‘Carpuccino’, operated by Bruno David, a driven, passionate Australian freshwater ecologist. It consists of a clever trap and even cleverer ‘digester’, driven by geothermal bacteria, turning an environmental disaster into a neat environmental win in the form of organic fertiliser.
I head east across the Waikato, past Te Kauwhata to a smaller stream off another lake to check it out. Carpuccino is easy to find, at the end of a gravel road around to the western edge of Lake Waikare. I hop over a gate and stare through a chain-link fence at this contraption, at once ordinary and brilliant.
It features a one-way gate allowing koi in, but not out. They thrash about in a large basket adjacent to a raised conveyor. The conveyor leads to a log mulcher, the product of which flows in turn to a faded red shipping container.
David and his team will find six to eight tonnes of carp in the trap during spawning season. The pests are hoisted up from the trap in a kind of fish-execution elevator, which slides them down the chute to be mulched, and from there the pulpy mess heads into the shipping container. Inside, micro-organisms known as geothermal bacteria get to work.
They’re brutally efficient. Within 48–72 hours, all that’s left of the carp—known for their leathery skin and dense skulls—is a fine brown powder reminiscent of ground coffee in consistency, if not aroma.
Because the carp are swimming in the dairy-intensive Waikato district, they hold abundant nutrients. There’s zinc, used to treat facial eczema in cattle. Potassium, to regulate their osmotic pressure. And nitrate, to aid bacteria in the rumen.These minerals are great for cows, but terrible in the water. Unless you’re koi, that is. They thrive in adverse conditions. And as the water in the Waikato has degraded, the koi population has exploded.
Today, koi carp represent an estimated 80 per cent of the biomass in the Waikato’s waterways, and experience on the five continents (only Antarctica is safe—so far) suggests once they’re established, getting rid of them is all but impossible.
A mature female can lay half a million eggs at a time, and their population density is now so high that their average weight has halved since they were first found. They are at capacity for the ecosystem.
The biggest casualties of koi’s bright, merciless march to dominance have been native fish and eels, whose numbers continue to drop precipitously.
You could forgive a passionate ecologist like Bruno David for being discouraged in light of this seemingly irresolvable downward spiral. Ever more intensive dairying degrades the water quality, the carp benefit, and their destructive foraging style exacerbates the turbidity. This further endangers native fish.
But David’s an upbeat chap, in love with his work. He has big, wild dreams, and the ability to get them put into motion. Carpuccino is the wildest, and has the most exciting potential. His plan is to take Carpuccino’s output and render it in tablet form. When placed underneath the native. trees his team plant on riparian margins, it has the effect of turbo-charging their growth and increasing survival rates.
It’s an idea that excites the mind—taking a pest filled with excess nutrients out of the water, using it to create fertiliser that is then used to help return riverbanks to their natural state. This provides a habitat for birds and, eventually, improves the habitat for native fish too. Better yet, it has the ability to be fiscally neutral.
“I like the idea of creating a funding stream from the invasive fish,” says David. “At no cost to ratepayers, we could run an invasive species control programme.”
David calls carp “nutrient vectors”—big sacks of nutrient-rich biomass, swimming around. When they’re captured and killed, that nutrient can be transformed from a ‘problem’ in one context into a ‘solution’ in another.
The prospect thrills him. “We’re wanting to create a moralistic tablet from these unwanted invasive species that we can then use in the right context,” he says. “We’re taking nutrients from an area—the Waikato—where it’s in excess, and putting it in the dunes, where it’s poor today but in fact it used to be rich.”
Such creative scientific thought, such knowledge of the ecosystem, such care over building something good from the carp problem. Ultimately, though, it involves the slaughter of fish in industrial quantities. And while David’s fancy machine is a sophisticated, moral assassin, all around the Waikato that weekend, there were dozens of more primitive killers.
The day after our mostly fruitless trip down to Huntly, Richie and I returned together to meet tournament organiser Allan Metcalfe, a bluff former dairy farmer with a thick grey-brown moustache, and his friend Philipp Loest. We arrived at Metcalfe’s home a few minutes west of Huntly—an old farmhouse, unwanted by the company that bought his farm, perched on a hill overlooking Lake Waahi. Metcalfe is kept busy by turning his homestead into a convention centre and venue, with 1000 guests booked for various events through Christmas.
We drive down farm trails and spendthe next six hours wading through the wetlands around Lake Waahi. The lake is cut in two by a private road running between the coal mine and Huntly Power Station, with an underpass for swans—a legacy of the ‘think big’ era, says Metcalfe. “The swans never used it.”
Despite the industry, the farming and the man-made intrusion into the habitat, down at the water it’s serene. The lake surround is skirted in parts with trees and bush and looks healthier than much of the rest of the region’s waterways. Still, Metcalfe ruefully recalls what’s gone: the deafening chorus of frogs that used to accompany his time down here, and the freshwater shrimp his kids once caught.
It crosses my mind, briefly and uncharitably, that it’s a little rich for a dairy farmer to be lamenting the loss of biodiversity in a lake which is bordered for long stretches by land his cattle once grazed. As if sensing it, he points out that he and his wife, Dawn—a fervent environmentalist—personally fenced the full seven-kilometre circumference of Lake Waahi, and says they farmed differently in his day.
“It’s not just one thing that’s harmed the waterways,” he says. “I never used nitrogen. Nowadays, they just pour it on.” Metcalfe is a different kind of farmer, from a different, fading era.
The shooting is slow this morning. The previous day, Loest snapped a string under the weight of the fish he was dragging, and still ended the day three fish behind Metcalfe. They pretend to be relaxed about their personal tallies, but I’m not convinced.
“You shot your three?” asks Metcalfe. “Can I start shooting yet?”
Loest goads him all day. “Allan was shooting here yesterday,” says Loest when we arrive at the lake, “so there’ll be a lot of wounded fish out there.”
That’s unlikely. Metcalfe may be older than 60, but he remains a crack shot. He turned to archery after a bad concussion ended his rugby career, and became good enough to represent New Zealand. He and Loest trade shots, hitting a koi every 15 minutes or so for a few hours. Eventually, appropriately, they end up even.
Metcalfe and I wait in the shallows while Loest lingers way out in the lake, on the other side of some trees. It seems he’s determined to win. Half an hour later, he comes striding back with a good-sized yellow koi, unable to suppress a grin. That fish has won him the weekend.
Despite the infrequency of action—at least compared to the really hot spots they never showed any interest in moving to a different location. Waahi is familiar; it’s koi bowfishing’s spiritual home. The last evidence of that era is a shed with a peeling wooden sign reading ‘The Koi Club’ further around the shore. We stop there for lunch after finishing for the day. Inside, one of the windows has been smashed by vandals, but years’ worth of records remain pinned to the wall.
The competing bowfishers all used to camp in the paddock behind the shed, have a big bonfire and get on the beers. Now the original crew are older, a little more restrained. But Metcalfe’s got more fight in him than he lets on.
“I’ll tell you what would really piss him off,” says Metcalfe, while Loest takes a break. “If I were to go out there and shoot one now.”
The thought proves irresistible. He sneaks off up the bay, and 15 minutes later, he’s back—with one last fish. “I had to shoot him in the head because I didn’t have my club,” he says. The arrow is dead between the eyes—the hardest shot in bowfishing. It’s sealed a draw. Loest smiles grimly.
An hour later, we’re back at tournament HQ at Lake Puketirini. For the first time, I’m witnessing the true nature of this competition—the bowhunting fraternity en masse. The participants are a mixture of slightly wild-looking men in their 30s and 40s, and a younger group who in bearing call to mind the taciturn survivalist set in the United States.
Nigel Mills is pale, freckled and very heavy, with a blue singlet on and dirty blond braids. He sits on a bench in the shade of the old railway station, waiting for the catch to come in—the first of a steady stream of fishermen that will flow through.
They’re there to complete the process and turn to a remarkable piece of Waikato technology. Stormin’ Norman is a sort of industrial-scale garden mulcher, a petrol-driven brute designed to mince halved sheep. It came from a ferret farm, and is named for the aged farmhand who first spotted it for sale. It eviscerates koi in a heartbeat and turns them into high-quality berley, for which demand has increased markedly since it lured in a monster snapper a while back.
There’s a lot of it to go round—four and a half tonnes by the time the last fish are weighed in. It’s a gruesome makeshift factory: there’s an expanding queue of utes and trailered boats full of carp snaking out of the lot, bringing the fish in, to be counted, weighed and transferred into tubs. Each load is often 25 kilograms or more, and is hefted across the tarmac to a six-by-four-metre wooden pen lined with a large blue tarpaulin. A tractor with Stormin’ Norman on the back is positioned over one end.
Berley customers take turns grabbing a tub, dragging it into the pen, then tossing fish after fish into the grinder. It makes a sound like a chainsaw running through live timber, disposing of a large koi in around a second. It’s efficient, but not a pretty process. Everyone who pitches up for berley comes away flecked with fish guts.
Koi are particularly fragrant—part of the reason they’re not considered edible, except in certain Asian cultures. We’re less than an hour from central Auckland, but this scene is everything I love about rural life—an amiable, community-uniting massacre.
Near the end of the two-hour weigh-in, the heavy-hitters start arriving—all with boats, all with dozens of fish. First Martin Brennan and Theo Ryks, a trans-Tasman team whose small alloy vessel’s hull is ankle-deep in fish.
Ryks jokes that he’s “the last of the dairy farmers”, and lives just up the road. Brennan wears trackpants and drinks beer. He’s over from Australia especially for the tournament, both to see his mate Ryks and because it’s not a pleasure available to him in his adopted home.
“Australia’s got too many stupid laws,” he says. “Every time I’ve tried, the cops have told me, ‘You can’t do that around here’.”
In New Zealand, not only do our officials allow it, they endorse it. Three men with the nightmare job title of ‘Partnerships Ranger’ are here from DOC, which sponsors the tournament to ‘raise awareness’ of the koi situation. What exactly that awareness will do to help matters isn’t made clear, and the department’s stance towards the bowfishers differs from that of Bruno David. The ecologist finds the event’s wanton slaughter both functionless from a control perspective (because it’s geographically so widely dispersed) and morally troublesome. “It’s not their fault,” he says of the koi. “People need to have a certain level of respect.”
There is little of that here this afternoon. The fish are pitched merrily from boat to tub to scale to tub to grinder with no great reverence. I find myself periodically dwelling on the emptiness of killing these thousands of fish, not for food and with no prospect of impacting on the unknowably vast population of the pest species.
I watch Ruben Hastings and Ben Passau—team ‘Monsters Inc’—disgorge their mammoth catch, well over 500 kilograms of fish for the weekend, and it feels a little barbaric. Hastings is in military-style camouflage fatigues: a compact, wiry man in his early 20s with an enormous, unkempt beard.
“There was this tiny inlet we found,” says Hastings of their epic, competition-winning haul. “It just opened up and carp were everywhere.”
I have misgivings about this event, but I can’t reconcile it with the affection I feel for this group—particularly Metcalfe and company. He, wife Dawn and a group of friends do all the heavy lifting for this peculiar event. They’re incredibly hospitable and genuine, glowing with pride and pleasure for the tournament they’ve now run for 25 years. And while they and DOC make the right noises regarding containing the problem, privately they’ll admit it doesn’t even scratch the surface in terms of control.
The World Koi Carp Classic is better described as an event that unites an otherwise quiet and dispersed group of people. For one weekend a year, they come together, kill a bunch of carp and enjoy one another’s company. For the Metcalfes, and the rest of the organisers, that’s enough.
“We’ve really only done it because we enjoy doing it,” says Gousmett. “And because people kept turning up.”