Māori knowledge and surveying paint a picture of wetland's past and present

A mix of modern science and indigenous knowledge are combining to paint a picture of Ahuriri Lagoon’s past and present – and to forecast for a better future.

A Mātauranga Māori (Māori knowledge) monitoring programme is being conducted on the culturally significant wetland as part of a wider project aimed at increasing its mahinga kai and ecological values.

Boffa Miskell environmental consultants are conducting surveys of fish – including tuna (eel) – and establishing an index of cultural health with the help from local Papatipu Rūnanga and the Ahuriri Lagoon Steering Group. The programme is funded by Environment Canterbury, the Government’s Freshwater Improvement Fund, and NIWA.

The surveys include observing or catching and counting fish  and observing and noting numbers of plants and, invertebrates.

It is a unique project aiming to demonstrate how to measure the cultural outcomes of the project, and whether the resulting changes over time to the lagoon will improve cultural outcomes for Ngāi Tahu Papatipu Rūnanga.

The programme is part of the Whakaora Te Ahuriri/Ahuriri Lagoon Project – a $3.5 million plan started in 2018 to reconstruct a wetland, which aims to improve biodiversity values, water quality and the future of mahinga kai both in the lagoon and further downstream in Huritini/Halswell River and Te Waihora/Lake Ellesmere.

Researching the past, measuring the present and forecasting the future

While surveying will help with a snapshot of current ecosystem health, the Mātauranga Māori programme is also taking into account indigenous knowledge, historical accounts and observations to help understand the area's past. That way, changes in ecosystem health over time can be put into a greater context.

Ahuriri Lagoon retains a strong significance to several local rūnanga, as it was an important historical place for gathering mahinga kai.

Boffa Miskell consultant Craig Pauling (Ngāi Tahu – Taumutu) said the programme is designed to give them a good idea of the waterway’s ecology now, in the past and in future.

“If we go back to not too long ago, we know that this area would have been completely covered in native species – there would have been no introduced species at all. That’s a good indicator, knowing from there what we should be aiming for,” he said.

Pauling added that we know the Huritini/Halswell River has been extensively modified – a large stretch has been turned from a meandering stream to an arrow-straight channel – but the effects that modifications had on ecology have not been well measured until now.

“When all the science is done, we can add in our mātauranga to the western science and get a more complete picture of what we want to achieve, which in a way is getting a better overall picture of the area here.”