LAKE ROTOMA, New Zealand —Once a riot of native plant species covered the shallows of Lake Rotoma, one of several bodies of water that sprinkle New Zealand’s upper North Island. At night, mottled green crayfish would come down from the depths to graze under the leaves in such abundant numbers that the local Māori tribe could collect a meal in a few minutes of wading.
Today, the bottom of the lake is covered with an alien canopy. Sharp spiral weeds, introduced by goldfish owners who dump unwanted tanks, form an impenetrable wall around the edge of the lake. Because they couldn’t get through on their daily commute, the crayfish largely disappeared.
Now the local tribe, Te Arawa, and conservation groups race to quell the weed’s explosive growth as it chokes out once pristine aquatic ecosystems. At Lake Rotomā, the tribe found a surprising solution in an age-old resource — contributing to a spirited debate about how ancestral Māori knowledge can complement conventional science.
Te Arawa, which has long used woven flax mats known as uwhi to cross water and gather food in shallow swamps, uses modern diving technology to staple uwhi underwater where aquatic herbicide has not worked or should not be sprayed. It has helped stop the weed growth and create new migration routes for the crayfish.
“This is a perfect example of combining mātauranga Māori” – traditional Māori knowledge – “and Western science,” said William Anaru, Te Arawa biosafety manager.
The use of uwhi is an example of the growing prominence in Western societies of indigenous knowledge systems, collected and passed on over the centuries.
In Canada, a 2019 law requires the government to consider Indigenous knowledge in regulatory decisions. In New Zealand, researchers inspired by mātauranga have investigated whether kauri forests are harmed by a lack of Māori prayer and the use of crushed whalebones to treat fungal infections that devastate native trees.
The phenomenon has proved controversial among academics unaccustomed to drawing on amorphous – and sometimes spiritual – systems of knowledge. The resulting backlash has split New Zealand’s scientific community, attracting interventions from one of the world’s foremost academics and sparking a debate about what it means to “know” something.
According to Dan Hikuroa, a senior lecturer in Māori studies at the University of Auckland, mātauranga Māori includes “knowledge, culture, values, and worldview.”
It covers everything from systematic observations about which plants grow best in certain areas or which stars to track across vast oceans, to legends that refer to particular rivers as home to taniwha – unpredictable supernatural creatures.
Such legends can be both literal and metaphorical, said Dr. hikuroa. Understanding a river as the home of a taniwha, for example, helps describe its sinuous appearance and warns of its volatility or ability to break its banks.
Moreover, mātauranga is not only a collection of knowledge, but also a philosophy supported by values such as kaitiakitanga and manaakitanga – guardianship and hospitality.
However, many of New Zealand’s more traditionally minded scientists view the spiritual and moral aspects of mātauranga as contradictory to conventional science, which is supposed to be value-neutral and limited to knowledge that can be empirically proven.
That tension came to a head last year when a collection of top New Zealand scientists published an open letter in The Listener, a major national magazine. In it, they rejected proposed changes to the school curriculum that would ensure “parity” between mātauranga Māori and conventional science and teach that “science has been used to support the dominance of Eurocentric views”.
Kendall Clements, a marine biologist who signed the letter, said they weren’t trying to disparage mātauranga, but to emphasize the differences between it and conventional science.
Mātauranga has the “seeds of science”, he said, “but to say that mātauranga Māori equals science makes no sense, because there are a lot of elements that are not in science, such as visions, prophecies and dance. .”
Proponents of mātauranga say this misses the point. dr. Hikuroa agreed that mātauranga is not the same as conventional science. But it’s valuable, he said, because it gives alternative explanations about the world and encourages people to think differently.
“If we try to explore that difference, we can collectively come to a better understanding of a solution than if we stayed away from a single knowledge,” he said.
As an example, Dr. Hikuroa on the construction of a state highway in the early 2000s. It was to pass through a swamp that local Māori said was inhabited by a rambunctious taniwha. Engineers had not identified any risks, but rerouted the road to allay their concerns. A year later, a major flood hit the area. The diverted road was spared major damage.
A taniwha was the “local tribe’s way of recording the observation made over the years that this place floods from time to time,” said Dr. hikuroa.
However, skeptics say that if the truth of the more spiritual aspects of mātauranga cannot be definitively proven, they cannot be called knowledge.
This tension between traditionally-minded scholars and mātauranga advocates, brought to a boil by the open letter in The Listener, sparked a fierce personal debate.
Proponents who had watched for years as scientists dismissed mātauranga as an unquantifiable superstition were prone to an alleged disrespect from the letter’s signatories.
Some argued that the letter was an example of white supremacy. Waikaremoana Waitoki, the president of the New Zealand Psychological Society, denounced the letter’s “racist tropes” and “moral panic”.
Others were frustrated that the letter’s authors lacked expertise in mātauranga. Melanie Mark-Shadbolt, an environmental sociologist, said it was motivated by “a little bit of fear” and “a lot of ignorance.”
The signatories, for their part, believed that their positions had been deliberately misinterpreted. “I believe that the vast majority of people who have attacked our letter have attacked misrepresentation,” said Dr. Clements. “Some of it was absolutely intentional.”
The prestigious Royal Society of New Zealand began investigating whether two of its fellows — the biochemist Garth Cooper and the philosopher Robert Nola — should face disciplinary action for signing the letter. Things got even more tense after polarizing British biologist Richard Dawkins denounced the Royal Society’s research and described mātauranga as “no science and not true.”
The commotion only recently calmed down after the Royal Society halted its research and Dr. cooper and dr. Nola chose to resign as fellows. Neither side is happy, but few have the energy to continue fighting.
Outside of these ivory tower debates, however, the use of mātauranga continues.
For Te Arawa, the fusion of mātauranga with conventional science has proved successful. A huge clearing has formed amid the weedy jungle in the shallows of Lake Rotoma.
The tribe turned to uwhi after becoming disillusioned with jute mats and herbicide, two alternatives that are more expensive and involve imported materials that often arouse suspicion among locals.
Cory O’Neill, Te Arawa’s lead diver, said the uwhi placed by his team are more effective than the jute mats or rubber mats, which can be ripped from the bottom of the lake by accumulated gas from degenerate lake weed.
In fact, while the uwhi stops thick weeds, thin gaps in the tissue allow leaner native plants to grow through them and create new forests of their own. Now, for the first time in decades, crayfish in Lake Rotomā have a clear path to ancient feeding grounds among the plants they relied on for millennia.
“We’ve essentially created a new mātauranga,” Mr. O’Neill said before carefully tucking his dreadlocks under the cap of his wetsuit and sliding into the lake. “And we’re going to use it to finish off the last weeds of the lake.”
