How do you know what a roto (lake) looked like 1,200 years ago? The answer is in the puehu – the dust, silt and pollen that entered the lake and very slowly built up over time.
Lakes380 – Our lakes’ health: past, present, future is a nationwide project to sample 10% of 3,800 lakes in Aotearoa over 1 hectare (about the size of a rugby field) in size. The Lakes380 team collected sediment cores from the bottom of each lake. Everything that happens in or around the lake leaves a trace in the sediment. As the sediments build up millimetre by millimetre, they create an environmental history of the lake and its surroundings.
Lake Moawhitu is located on Rangitoto ki te Tonga D’Urville Island in the Marlborough Sounds. It is a coastal lake and was once an important source of mahinga kai for local iwi Ngāti Koata. Mātauranga and oral histories from Ngāti Koata have provided a picture of the roto and its catchment from when their tūpuna settled in the area. Evidence from sediment cores are able to support the oral histories and look even further back in time, before people were present in Aotearoa and around Lake Moawhitu.
The historical scientific data we collected in lake sediment cores has shown us what the lake would have looked like, including the vegetation surrounding it and the animals that lived in it, and the oral histories helped us understand the relationship the people of Ngāti Koata have with Moawhitu.Mckayla Holloway, Cawthron Institute and Lakes380
Restoring the mauri of Lake Moawhitu
Due to significant changes in the catchment, the mauri (health) of the lake has been in decline for many decades. Ngāti Koata Trust and the Department of Conservation have teamed up to improve the water quality and restore the lake ecosystem. This upholds the concept of te mana o te wai – if we take care of the water, it will take care of us.
Te mana o te wai describes the first right for water being with the water – lakes, rivers and streams as well as the ocean. The health and wellbeing of water is of vital importance for all living things and must come before other concerns.
The Lakes380 team is providing data to help inform these efforts. Information from the sediment cores showed that, prior to human arrival, podocarp (rimu, kahikatea and mataī) and beech forest were abundant in the region. Pollen grains from flax were also in the cores, and local mātauranga identified the species as wharariki. This knowledge from the past creates a more accurate (and likely successful) restoration plan.
Kotahitanga, or collaboration, is important for lake restoration because a lot of work is involved, and it can take a long time. Ngāti Koata Trust and the Department of Conservation are leading catchment restoration work that includes hands-on planting of native vegetation. It also has a virtual component where Ngāti Koata Trust and Lakes380 have used mātauranga and scientific data to build a browser-based virtual experience: He reo nō te puehu – A voice from the dust. Users can visit four virtual 360-degree worlds: Pre Human, Māori Settlement, Present Day and Future 2122. Each world contains videos, pop-ups with images and facts and immersive experiences in the roto and on the whenua. The virtual worlds illustrate how much the lake and catchment have changed but also inspire hope about restoring the area and its links with mahinga kai.
He reo nō te puehu – A voice from the dust has been instrumental in creating a number of connections. It connects tangata whenua Ngāti Koata with their roto as it once was – and may possibly be again. It makes connections between mātauranga Māori and conventional science – enhancing both knowledge systems. It also shows how innovative and effective science communication can create meaningful connections with a wide audience.
The project also highlights whakapapa – relationships between things within an ecosystem. At Lake Moawhitu, Ngāti Koata relied on tuna for food and plants that grew around the lake for clothing, shelter and tools to catch tuna. Tuna relied on aquatic plants growing in the lake and the pristine water that was cleansed by the ngahere (forest) growing around the lake. The wairuatanga (wellbeing) of all things relies on these connections and the correct balance between them. That’s the vision at Lake Moawhitu – to restore this balance in order to restore the mauri of the lake.
This virtual reality experience really brings the restoration kaupapa to life in a powerful way – you can see for yourself how majestic the lake was and the stark contrast of how degraded it has become, but it also presents an exciting vision of what the future could hold if we continue with our restoration work. This gives us hope for the future of Moawhitu as a significant mahinga kai once again.Alice Woodward, Ngāti Koata
Nature of science
A myth of the nature of science is that science is procedural rather than creative. Creativity is needed in all aspects of scientific research from coming up with a research question through to the dissemination of the results. Science communication can take many forms. The Lakes380 project uses a continuum of methods from the conventional journal publications through to creative and cutting-edge virtual reality.
Māori have a special relationship with water in all its forms – it is taonga. The interactive Wai Māori explores some of these values and connections.
Science, mātauranga Māori and social sciences are interwoven throughout the Lakes380 programme. The article Lakes380 – a context for learning includes key concepts, curriculum links and additional pedagogical help.
The interactive Finding the clues – inputs and lake sediments explains how sediments end up in places like Lake Moawhitu.
Find out more about the ‘Communicating in science’ strand in the New Zealand curriculum.
Encourage students to try out He reo nō te puehu – A voice from the dust for themselves. This activity provides background information about the site and questions to deepen student learning.
Get hands-on to learn about the secrets found in lake water with the activity Finding out what’s in our lake using eDNA.
This resource has been developed in collaboration with Lakes380 – Our lakes’ health: past present, future (C05X1707), Cawthron Institute and GNS Science. The virtual world was developed through a collaboration between Ngāti Koata, Department of Conservation, Mckayla Holloway (Lakes380), Russleigh Parai (Lakes380), Jacob Barrow (Shadow Space), Jeﬀ Brass (GNS Science), Bruce Green (Cawthron Institute), Kirsten Revell (Revell Design), Bob Bickerton and Solomon Rahui.