It’s not too late to save our lakes, say scientists as national study confirms 45% of lakes are in poor health

17 April 2023

Five years after commencing the biggest survey of lake health in Aotearoa New Zealand’s history, Lakes380 Programme leaders at Cawthron Institute and GNS Science say there has never been a stronger call to action for New Zealanders to work together to improve the health of our precious lakes.

“Unfortunately the news isn’t good, with the results of our surveying and modelling revealing that over 80% of lakes in the North Island and 45% nationally are in poor or very poor health,” says programme co-leader Dr Susie Wood of Cawthron Institute.

These results align very closely to the findings of the Our Freshwater 2023 report released by the Ministry for the Environment and Statistics New Zealand this week, confirming the seriousness of the challenges facing Aotearoa New Zealand’s lakes.

“Nutrients are leaching into our lakes, sediment is smothering the lakebeds, non-native species are irreversibly changing their ecology and they are being overtaken by algae blooms. As a result of this degradation, these lakes are losing biodiversity and many are no longer safe to swim in or harvest food from.”

“But, it’s not too late to save our lakes from passing ecological tipping points that will be even more difficult to recover from, if we come together and make some big changes now.”

Wood says although the initial five-year funded Programme has come to an end, the research team intends to continue this important work and is currently seeking funding to do so.

“The benefits of the data and tools produced by the Lakes380 Programme are just the beginning – after completing the biggest lake health survey in our nation’s history, we understand the scale of the challenge facing us and have the engagement of communities across Aotearoa New Zealand who care passionately about making a difference.

“The next step is to start building the biggest lake restoration effort in the history of Aotearoa New Zealand. We need to develop better monitoring tools and systems, and innovative new restoration solutions.”

“We’re seeking funding support from Government to do this.”

The ambitious Lakes380 Programme, funded by the Ministry of Business, Innovation and Employment’s Endeavour Fund, and co-led by Cawthron Institute and GNS Science, kicked-off in 2017 with the lofty target of sampling 10% of lakes in Aotearoa New Zealand.

Programme Co-Leader Dr Marcus Vandergoes of GNS Science says the work involved going beyond sampling the water and sediment in the lakes, and collecting and analysing lake sediment cores that can provide the history of a lake dating back more than a thousand years, pre-human arrival in Aotearoa New Zealand.

“In addition to the data collected from sampling, a huge focus was working with communities to understand more about their relationships with their lakes and sharing information that can inform restoration actions,” Vandergoes says.

“The quality of the scientific research that has been carried out through Lakes380 is truly impressive. We’ve developed methods and tools that will empower not only researchers but also managers and communities to better monitor and understand the health of their lakes, like environmental DNA (eDNA) monitoring tools that can easily detect the presence of taonga species like tuna (eel) and kākahi (freshwater mussels).”

A truly national effort, the team of researchers represented organisations including GNS Science, Cawthron Institute, Te Herenga Waka Victoria University of Wellington, Otago University, Auckland University, Matana Consulting, Waka Taurua Consulting, and international researchers from the UK, USA and Australia. Another group of stakeholders was involved in guiding and supporting the Programme’s objectives, including a large number of iwi/hapū/whānau groups whose permission was sought before sampling took place, and central and local government organisations and conservation groups.

The team has also been supporting the inclusion of mātauranga Māori in lake monitoring and management, drawing on and integrating knowledge of iwi/hapū as kaitiaki, and working closely with four iwi groups – Ngāti Koata in Te Tauihu, Ngā Puna Rau o Rangitīkei in Rangitīkei district, Ngāti Kahungunu ki Wairarapa & Rangitāne o Wairarapa in Wairarapa, and Te Rūnaka o Ōtākou (Kai Tahu).

Vandergoes says we now have a good platform to build on to support restoration action.

“Our research team are currently working hard to secure funding to continue this work that will support restoration efforts. I’d encourage New Zealanders to visit and view the data we have produced for the lakes in their region, as I think some of the results may surprise people in terms of understanding why our lakes are in the state they are in, and what has happened in their history.”

“We all have a part to play in protecting and restoring our lakes, and it’s not too late to make a difference that will benefit future generations.”

– Explore our Lake Water Quality App

– View lake health information sheets available that summarise the data from many of the lakes we have surveyed

– Watch videos about our research via the video gallery on our website

– Visit 

Image: Lakes380. A team of over 70 researchers sampled 10% of Aotearoa New Zealand’s lakes during the five year research Programme.

Dr Susie Wood (Cawthron Institute) and Dr Marcus Vandergoes (GNS Science), co-leaders of the Lakes380 Programme.

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