PFAS contamination in freshwater food sources : a study on Aotearoa New Zealand's freshwater fish : a thesis submitted in partial fulfilment of the requirement for the degree of Master of Science in Ecology at Massey University, Palmerston North, New Zealand

Abstract

PFAS (per and polyfluoroalkyl substances) have become major potential toxicants of humans and wildlife over the last decade. PFAS are a class of environmentally persistent synthetic chemicals that have been detected in groundwater, drinking water supplies, freshwater fish, and even marine mammals. This has raised concern in many communities that rely on these freshwater species as food sources. Although PFAS concentrations have been assessed in some New Zealand waterways and marine mammals, surprisingly, only one study, limited to two eel samples has examined PFAS levels in commonly consumed New Zealand freshwater fish. To investigate distribution, concentration and composition of PFAS across different locations and fish species, I collected six fish species across seven sites North Island, New Zealand. Livers and fins from wild-caught fish provided by local Salmonid anglers, tangata whenua (indigenous communities), and me were analysed for 75 different PFAS. Native shortfin eels Anguilla australis (Richardson, 1841), a culturally significant food source for Māori, were found to have higher total PFAS. In some samples, levels in the liver exceeded Food Safety Australia and New Zealand (FSANZ) trigger values. Concentrations of perfluorooctanesulfonic acid (PFOS) in the fish fins were strongly correlated with those in the fish liver, indicating that fins may serve as a useful non-lethal proxy for assessing PFOS contamination in fish. Overall, the results highlight the importance of addressing PFAS contamination in New Zealand’s freshwater environments at a wider scale and signal potential consequences for public health, long-term sustainability of fisheries, and viability of export markets in New Zealand.