Ngāi Tahu is collaborating with marine scientists to study the importance of kelp beds in buffering the effects of ocean acidification in East Otago and Akaroa taiāpure. Photo / Supplied. Photo / supplied
Ngāi Tahu is collaborating with marine scientists to study the importance of kelp beds in buffering the effects of ocean acidification in East Otago and Akaroa taiāpure. Photo / Supplied. Photo / supplied
Opinion by Lisa Tumahai, Kaiwhakahaere (Chair) of Te Rūnanga o Ngāi Tahu
OPINION
As a seafaring people, our oceans have always been a critical element of our identity as Ngāi Tahu.
Our ancestors travelled to Te Waipounamu using the moana to sustain themselves, and once here they continued to rely on the coast and sea.
Sadly, hundreds of years later, our moanais in a perilous state.
The Government’s Our Marine Environment report confirms sea levels are rising fast – twice as fast as in the previous 60 years. Rising tides pose real challenges to our coastal marae and whenua across our Ngāi Tahu takiwā.
But there are two other threats discussed in this report that may be far more detrimental to our people: Ocean warming and acidification.
The effects of a warmer and slightly more acidic sea can be devastating. A fractional change in temperature or pH level can trigger drastic changes to ecosystems.
Ministry for the Environment and Statistics New Zealand publish this report every three years. It outlines key environmental indicators and the findings of peer-reviewed studies to paint a picture of our marine environment. And it’s really worrying.
It tells us open ocean acidity has increased 8.6 per cent in the subantarctic surface water off the coast of Ōtākou (Otago) between 1998 and 2020.
Lisa Tumahai is the kaiwhakahaere (chairwoman) of Te Rūnanga o Ngāi Tahu. Photo / Supplied
Marine heatwaves are becoming more frequent and severe, and on average the sea-surface temperature increased by 0.1 degrees C to 0.2 degrees C per decade across the four oceanic regions.
There are thousands of salmon dying in Marlborough Sounds marine farms because of changing sea temperatures.
My thoughts turn to our native taonga species and how they will fare.
Studies show it’s the marine realm that is witnessing the largest climate impacts.
In acidic waters shellfish struggle to grow and reproduce. Molluscs – pāua, kōura, cockles, and pīpī – are particularly vulnerable.
Chemistry and temperature changes are expected to have a particularly strong effect on calcifiers, organisms that form carbonate shells such as mussels.
Pāua grow more slowly under acidic conditions and their shells show clear signs of dissolving.
Our fish stocks are changing. Temperature and nutrient pattern trends may lead to the southward migration of many fish species into the waters around Aotearoa.
Studies showed that during the 2017–18 Te Waipounamu marine heatwaves, bull kelp suffered losses in Kaikōura and were completely lost from some reefs in Whakaraupō Lyttelton.
So that’s finfish, shellfish and even seaweed. All of which fill our mahinga kai kete. Food that is key to our Ngāi Tahu identity.
To combat this, Ngāi Tahu is collaborating with marine scientists to study the importance of kelp beds in buffering the effects of ocean acidification locally, long-term. We’re deploying benthic moorings in both the East Otago and the Akaroa taiāpure.
We’re also collaborating to undertake restoration work in key traditional fishing grounds focused on adapting to the impacts of climate change, such as the reseeding of pāua.
Climate adaption policies would do well to draw on the traditional ecological knowledge gained over hundreds of years of managing and gathering mahinga kai.
A step in the right direction is last’s month appointment of an Interim Ministerial Advisory Committee to develop a framework for te ao Māori climate crisis responses by engaging with Māori and ensuring they have a voice at the decision-making table.
This committee, which includes David Perenara-O’Connell (Ngāi Tahu, Ngāti Mamoe, Waitaha, nō Taumutu), Michael J.Stevens, (Ngāi Tahu, nō Awarua), and Veronica Baldwin-Smith (Ngāi Tahu, nō Ngāti Waewae), has been established to help ensure whānau, hapū, and iwi are at the forefront of the Government’s climate change response using mātauranga Māori to help better inform decision making.
University of Canterbury research shows māramatanga for each hāpu provided guidance for the timing of gathering mahinga kai. This includes the gathering of shellfish and other seafood, planting and harvesting of crops and food.
For hundreds of years our people have relied on understanding minuscule changes in the environment for their very existence. Our mātauranga can play a crucial role in dealing with the climate crisis, so I look forward to seeing the mahi from the advisory committee ensuring Māori are at the heart of the climate response in Aotearoa.
