A kelp restoration project that seeks to restore flourishing marine ecosystems is getting underway in Whakaraupō Lyttelton Harbour through a collaborative partnership that brings together scientists, iwi, a marine conservation charity and sport.
It builds on ongoing research into the restoration of native rimurimu (or Giant Kelp) in selected South Island sites where kelp has been wiped out due to rising sea temperatures and sedimentation. Led by Otago University’s Matt De Roe in collaboration with hapū of Te Rūnanga o Ngāi Tahu, the focus is on identifying and developing ‘climate resilient’ rimurimu for the best chance of restoration success.
Through 2023 the project known as Māra Moana extends and kicks off in Whakaraupō Lyttelton Harbour. A local Ngāti Wheke team is leading the underwater and coastal effort to harvest the invasive and undesirable kelp (Undaria pinnatifida) and will outplant small tiles reseeded with rimurimu spores.
The wider project is ultimately about restoration with scientists looking to develop toolkits for handover to communities invested in looking after their local areas, and Whakaraupō Lyttelton Harbour is a test bed for this approach.
“We aim to support customary and community-led approaches to marine ecosystem management and restoration. It’s important to be working with local people as they understand their local environment best and have the energy to drive change. Supporting and working alongside tangata tiaki allows them to share their knowledge and guide our research. It also means the outcomes of the research are then left in the hands of those that can continue the hard work,” says Matt De Roe, Research Fellow at Otago University’s Department of Marine Science.
Marine conservation charity Live Ocean Foundation is part of the collaboration supporting the training and upskilling of local Ngāti Wheke divers. As the charity partner of the NZ SailGP team, Live Ocean is the recipient of prize-money coming off the back of the sailing team’s success in recent international SailGP events and this is helping with the Whakaraupō Lyttelton Harbour extension of Māra Moana.
“The ocean is changing fast and warming seas are creating new and complex challenges for the life in them. This is restoration in action which is really exciting, and it’s the kind of thinking that’s needed as we look to the future. To see scientists, Ngāti Wheke and sport lean into this is special,” says Sally Paterson, Live Ocean Foundation Chief Executive.
In Aotearoa New Zealand we’re experiencing longer and more intense marine heatwaves which go beyond the thermal threshold of some of our native kelp populations, likely having significant effects on kelp forests in Lyttelton.
Spores from intact populations of rimurimu have been collected and taken to the laboratory at Otago’s Portobello Marine Lab where small ceramic tiles are ‘reseeded’ with hundreds of spores for out planting into the decimated areas. Removal of the invasive Undaria in Lyttelton Harbour started late last year driven by Te Rūnanga o Ngāi Tahu with funding from Land Information New Zealand. Outplanting trials of native rimurimu will commence in March 2023 and continue through the autumn and winter months.
John Kottier is Program Manager for the Ngāti Wheke Christchurch team involved in the on and under-water work. He remembers when Lyttelton Harbour wasn’t facing this challenge and is optimistic. “This is our opportunity to restore what the ocean and coast here has lost. Being involved in this project from these early stages means we’ll have the skills and knowledge locally to continue this vital work.”
Throughout the year the Otago University research team will continue their work (made possible by the Centre of Research Excellence – Coastal People Southern Skies) to identify and develop ‘climate resilient’ rimurimu.
Matt De Roe explains, “To date, our work has been focused on better understanding kelp populations around the South Island of New Zealand and now we are moving toward actively restoring those that have been lost and buffering those that remain.”
Kelp from multiple locations, including Marlborough, Banks Peninsula and Otago have been genetically characterised and physiologically tested to understand not only how connected they are, but also if they have resilience to warming ocean temperatures.
“We want to identify thermal resilience markers so we can screen populations to identify the individuals that have a higher resilience to climate change impact. Then we start breeding stock from those individual kelp we know are more likely to survive and use them in our restoration efforts.”
By the time the optimal reseeding window of early Spring arrives it’s expected that Ngāti Wheke divers will be reseeding climate resilient rimurimu into Whakaraupō Lyttelton and the harbour’s marine ecosystem will be one step closer to a healthy future.
Pictured below from left: Matt De Roe (University of Otago), Finn Henry (NZ SailGP team), Sally Paterson (Live Ocean Foundation), John Kottier (Ngāti Wheke)