
Environmental Health Report: Climate change and toxic freshwater cyanobacteria in Aotearoa NZ
Please note: As of 1 July 2025, the New Zealand Institute for Public Health and Forensic Science (PHF Science) is the new name for the Institute of Environmental Science and Research (ESR). Research and reports published prior to this date may reference the organisation’s former name.
Summary
Climate change is already impacting freshwaters in Aotearoa New Zealand, and cyanobacteria, or blue-green algae, are expected to flourish with continued climate change. Many cyanobacteria species produce toxins that pose a health risk to animals and humans through physical contact, or by consuming them via contaminated water or aquatic foodstuffs. This review assesses the impact climate change will likely have on problematic cyanobacteria in Aotearoa New Zealand and how these changes could impact human health.