- Aotearoa New Zealand’s green-lipped mussel industry provides a relatively sustainable source of animal protein, but the plastic ropes used to catch mussel larvae are a source of marine plastic pollution.
- Researchers are using mātauranga (Māori traditional knowledge) and Western science to work out whether natural fiber ropes, made from native species traditionally used by Māori, could provide a suitable and biodegradable alternative.
- Mongabay spoke with Indigenous researcher Nicola Macdonald about the research process, the findings so far, and the team’s hopes for helping create a more sustainable aquaculture industry.
At low tide, on many a craggy corner of Aotearoa New Zealand’s coastline, you can find clusters of large, oval, emerald-and-gold bivalves, encrusted with barnacles and sucked tightly onto the rocks. They’re quick to pick and easy to prepare: boil or steam them for just a couple of minutes, and the shells spring open to reveal the salty, chewy meat.
Green-lipped mussels (Perna canaliculus), known as kuku and kūtai in the Māori language, are endemic to this place. As well as growing wild, they are farmed on floating lines in many of the country’s calmer bays and harbors — a form of aquaculture that can yield a large amount of nutrient-rich animal protein with a relatively small carbon and freshwater footprint.
But green-lipped mussel farms are also responsible for a large amount of plastic waste. Mussel farmers usually use plastic ropes to “catch” wild mussel larvae, which attach to the ropes and become “spat,” or seed mussels. These ropes are sometimes lost into the ocean, and regularly end up in landfill at the end of their life cycle, as they are not always recyclable.
Given that microplastic particles have now been found inside green-lipped mussels, as well as in many other marine species — which can harm the animals, their habitats, and the humans who eat them — many local iwi (Māori tribes) representatives and scientists have highlighted the importance of finding alternative aquaculture gear that doesn’t contribute to the problem.
With this in mind, a team of Māori and tauiwi (non-Māori) researchers and project partners are employing mātauranga Māori (Māori knowledge) and Western science in the cause of developing an effective, biodegradable alternative to plastic spat-catching rope out of native plant fibers.
Māori have many centuries of experience at using natural fibers to make ropes that can be used in marine environments, and deep knowledge of how to identify, cultivate, and process native plant fibers for this purpose.
The Kōhanga Kūtai (Mussel Nest/Nursery) project is supported by the Sustainable Seas National Science Challenge and co-led by kairaranga (master weavers) from two Māori iwi, Ngāti Manuhiri and Ngāti Rehua. It involves scientists at the University of Auckland and the Manaaki Whenua – Landcare Research institute, as well as three Māori aquaculture businesses: Aotea Marine Farms, Rough Waters, and Whakatōhea Mussels (Ōpōtiki). Also involved in the project are the curators of Te Kohinga Harakeke o Aotearoa – National NZ Flax Collection, a collection of traditional weaving varieties of harakeke (New Zealand flax or hemp, Phormium tenax).
Mongabay caught up with Nicola Macdonald, descended from the Ngāti Rehua, Ngāti Wai, Te Rarawa, Te Atiawa, and Ngāti Maru ki Taranaki iwi, who is the chief executive of the Ngāti Manuhiri Settlement Trust(NMST) and one of the project’s co-leads.
She spoke about how the project is going so far, and the challenges and opportunities of working with mātauranga and Western science to further environmental and economic ends in the country’s sustainable aquaculture sector.
INTERVIEW WITH NICOLA MACDONALD
Mongabay: How did the Kōhanga Kūtai project come about?
Nicola Macdonald: Well, let me start with some background. Our hapū [subtribe] of Ngāti Manuhiri settled our treaty grievances in 2011. (Note: This was redress for breaches of the guarantees set out in the 1840 Treaty of Waitangi that was signed by the British Crown and a number of Māori chiefs.)
Our area of interest is quite large — it starts from the top of the Bream Tail, includes all the inner and outer islands of the Hauraki Gulf, comes right into the heart of Auckland City, and stretches out into the West Coast, through the Waitakere ranges and up through Kaipara. We take our name from our tupuna [ancestor] Manuhiri, who was born in Kāwhia and settled our areas in the 14th century. So as a people, Ngāti Manuhiri have occupied our ancestral lands since then till the present day.
Part of our treaty settlement looks at the way in which we increase our cultural footprint, the way in which we hold and protect and increase our cultural intelligence — our mātauranga — and also how we can provide future aspirations for ourselves as a hapū. To do that, we have different relationships with the Crown’s agencies and other interested stakeholders.
The University of Auckland’s Institute of Marine Science is one of those groups with which the Settlement Trust has a formal relationship, which describes the way our areas of interest in science and in research intersect, particularly around the marine space, and we work closely with several researchers and professors of that institute.
One particular project that interested us quite a lot was investigating how we can support mussel spat in the water without using plastic ropes. The university approached us to see whether we would be interested in doing research on that topic that incorporated mātauranga Māori and Western science.
Mongabay: What sets this research process apart from a more conventional “Western science” approach?
Nicola Macdonald: Well, for anything where you’re looking at different worldviews and lenses, there’s a process around how you incorporate and keep the integrity of an Indigenous science that’s going to be used in a Western science outcome. So, we’ve had to run parallel to one another — using the Western science and technology to look at the functionality of mussel spat, and then alongside that, looking at what Indigenous technologies we would consider important to be included.
For us, that meant starting with a workshop with our kaumatua [elders] that were knowledge holders of the different forms of taonga [highly prized] species. It meant looking at a maramataka, which is a seasonal calendar that tells us when things are ready for harvesting and planting. And also looking at the different types of plants that we thought might be suitable as a way of holding mussel spat, outside of those plastic ropes.
So, the way we worked involved a series of wānanga [intensive workshops] with those knowledge holders, and then we moved into the actual ngāhere [forest]. We made a number of different visits: these things aren’t done in one day, they’re done over a season, so that’s a different way of working when you’re looking at Western science that has very specific ethics frameworks and time frames and deadlines. The natural world has its own clock, and that’s the way we needed to work, in conjunction with Papatūānuku [Mother Earth], in conjunction with nature, and to allow nature to tell us “this plant is ready for harvest.”
Mongabay: Which plants have you tested out so far?
Nicola Macdonald: We’re so lucky because we have a full pharmacopoeia of plants: we’re just so fortunate that the ngāhere produces so many different taonga, and each one has different properties and different benefits.
We trialed over 15 types of fiber. One was kuta [swamp reed, Eleocharis sphacelate], which is an underwater reed, found in certain lakes — and I won’t disclose where the lakes are because it’s very highly prized and once people know where they are, oh my goodness! So kuta is traditionally used in tukutuku [decorative wall panels], and we had to dive for it.
We’ve also trialed harakeke. There are 30 to 40 different varieties in New Zealand, and we tried a few of them, from the very fine harakeke called kōhungahunga, which is used for fine cloaks and is almost like a silk, to more hardy plants that you’d use perhaps for baskets for gathering kaimoana [seafood], which are quite strong and durable. We’ve trialed tī kouka [cabbage tree, Cordyline australis] too.
We also trialed pampas [Cortaderia spp.], a fiber that is not a taonga species and is not native to Aotearoa. But it is a pest plant, so we decided to see if it had any properties that might be of some use.
Mongabay: How do you make the fibers into ropes?
Nicola Macdonald: Well, first we go out to harvest according to our maramataka, and we have karakia [prayers] that we use, and tikanga [protocols] to follow, such as never harvesting when it’s raining, or when we are menstruating. We harvest the plant in the ways that our foremothers and forefathers have taught us, and we usually prepare the leaves on-site.
The traditional way to process the fibers is to use a very sharp mussel shell to scrape all the fleshy parts off the plant so you’re just left with the long stringy parts. We’ve also been trying different kinds of equipment for extracting the fiber, such as a sheep-shearing comb, which has lots of little metal teeth in it. Then we twist and roll them into quite rough, bristly ropes: what we’re trying to create is a kind of rope that has lots of little strings coming off it and is quite billowy, so that it can attract the spat and provide lots of landing spaces for them to attach themselves onto.
Mongabay: Which fibers are faring best in the trial?
Nicola Macdonald: We found that the kuta fiber was too brittle, and it didn’t hold up underwater as well as the others. Tī kouka, however, had long tendrils and flowed quite beautifully underwater, and so did harakeke. The pampas is also proving to work quite well, so we’re very keen on investigating this one even further, because it’s such an invasive weed along our coastlines. Unfortunately, due to COVID-19 lockdowns, we are slightly behind in our work plan, so we are still at the stage of refining and finding out what works best.
Mongabay: How have you found the experience of collaborating with the university on this project?
Nicola Macdonald: We’ve got a really good relationship with the Institute of Marine Science. Professor Andrew Jeffs is the co-investigator alongside myself, and he and I have worked together previously on the Auckland Conservation Board. We have a covenant between the university and Ngāti Manuhiri that sets out the ways that we work together, and our values, and there are many things that are shared and aligned.
It’s really important when you’re beginning a relationship between Māori and non-Māori to invest the time in the relationship foundations — after 180 years of being colonized, Māori don’t mind waiting another 180 years! Getting the relationship right will then ensure that the journey we go on is a journey where we are walking side by side.
Mongabay: Any challenges in the research process so far?
Nicola Macdonald: Yeah, I think there are always challenges when we’re looking at Indigenous knowledge in a Western science construct. And the challenge is always about keeping the integrity of ancestral knowledge that passes from generation to generation. As I mentioned earlier, our ancestors came here in the 14th century. So, there’s a lot of responsibility as to: how much do you share? How much do you give? And will that knowledge be looked after and cared for in the right ways? That’s always a challenge for ourselves as tangata whenua [people who have customary authority in a particular place].
I think the journey is made a lot easier when we have a meeting of minds between both partners to the kaupapa [topic, initiative]. But there’ve been some things the university have asked us about and we’ve said “no, we’re not going to go into that space,” and they’ve been very good about it, they’ve been very understanding. And in the end, we’re all wanting to achieve the same outcome, which is to protect te taiao [the environment], and to utilize our different intelligences in ways that will benefit Tangaroa [the Māori god of the sea] and his whanau [family; in this context, marine life].
Mongabay: Do you think the use of natural fibers for mussel farming can be sustainable at larger scales? Is there any interest yet from mussel farmers and the wider community?
Nicola Macdonald: In the Hauraki Gulf, and across a whole lot of coastal areas in New Zealand, microplastics and plastic pollution is a serious issue to tackle. So, we’d love to see the use of more natural fibers. There’s a whole movement in our country around jobs for nature as a result of the COVID pandemic; we’re looking at green economies, and ways in which communities can work together.
We know that something that is organic, that breaks down without causing harm to other fish species into the marine habitats, like a natural fiber, is far better than the plastic ropes that we’ve got right now. We’re still testing out the durability of the natural fiber rope in seawater, and exploring the ongoing sustainability of a natural fiber approach.
If the research is successful, we’ll be promoting that to mussel farmers. And mussel farmers are telling us that they have these concerns as well, which is really great. In terms of sourcing those fibers, our expectation will be to work directly with mana whenua [customary authorities] and iwi and communities to establish large-scale plantations, which can be utilized for environmental and commercial activities. Tikanga Maori [customary practices] ensures sustainability of our natural resources and our existing native fiber plantations.
Kōhanga Kūtai has also resonated amongst a lot of other hapū in Aotearoa, and it’s really inspired a lot of kairangahau [weavers] in the communities, which was an unintended but very positive outcome. And I guess it’s because it takes a whole-of-community approach to address an issue that we want to put right. And that’s what I love about it, is that it can be a whole-of-community approach. It can include Māori and non-Māori. The best thing is that we’ve all got the right intentions, which is to look after our taonga — our treasures from our ancestors.
Related listening from Mongabay’s podcast: Hear Nicola Macdonald discuss these issues in greater detail, plus an archaeologist shares what her team is learning about ingenious, ancient, Indigenous clam gardens in the Pacific Northwest region, listen here: