Many North Island lakes are in poor health, a study says. Photo: Supplied / ThermalAir
New Zealand scientists say almost half of the country's lakes are in poor health, but it's not too late to fix them.
Lakes380, a collaborative project between GNS Science and the Cawthron Institute, wants more resources to clean 1700 lakes that are contaminated.
The project has been measuring the health of lakes throughout Aotearoa.
"A combination of traditional environmental reconstruction techniques and more recent methods (such as environmental DNA and high resolution core scanning) will be used to collect data that will allow us to characterise current lake health, and explore rates and causes of change over the last 1000 years," the Cawthron Institute said on its website.
Co-leader Susie Wood said it will be hard, but action needs to be taken before it is too late.
"Our lakes are incredibly important, obviously culturally, socially and environmentally.
"You know, we're worried because we're losing places that are culturally significant. Our native freshwater species, most of them or many of them are threatened and declining in numbers."
Wood said the situation is much worse in the North Island, where almost all of the island's lakes are under threat.
"Up in the North Island of course our landscape has been much more modified, so we've got a lot more urban development, a lot more farming and forestry.
"What happens on the land really has a significant impact on the water quality."
The group has launched an app measuring lake water quality which can be found on their website.