Why are otherwise healthy lakes all over the world turning bright green?
Researchers at Nelson's Cawthron Institute are co-leading an international collaboration looking into this puzzling phenomenon.
The Institute's Dr Simon Stewart joins us to explain what could be behind this scientific mystery.
There are several lakes in New Zealand that are already experiencing these blooms, including Ōtūwharekai (Upper Māori Lake) near Ashburton. Photo: Cawthron Institute / Supplied
