A kai consumption survey was completed by 34 whānau members in 2013 which provided the underpinning knowledge required to understand the spatial dimensions of whānau interactions with mahinga kai sites and species in the Te Waihora catchment. Selected mahinga kai species were sampled from Te Waihora catchment in November 2013, including longfin and shortfin eel (tuna), brown trout, wai kākahi (freshwater mussels), swan eggs and watercress, along with other important taonga species such as raupō (bullrush). In addition, the surficial sediment that is in contact with lower trophic species, from which bioaccumulation up the food chain occurs, were also sampled at the same time to provide information on potential source “hotspots” of contamination. Bioaccumulative contaminants, including heavy metals (e.g., mercury, arsenic) and organochlorine contaminants (e.g., DDT, PCB, dieldrin), were measured in the samples collected. The contaminant concentrations in mahinga kai species were then compared with national and international studies and the levels in commercially produced applicable foods.Sediment heavy metal concentrations were all below Australian and New Zealand Environment Conservation Council (ANZECC) Low Interim Sediment Quality Guidelines (low-ISQG).Total organic carbon normalised ΣDDT concentrations in sediments from Taumutu Lagoon, Halswell River and the Kaituna River were above ANZECC low-ISQG, suggesting that these are potential organochlorine “hotspots” in Te Waihora catchment. ΣDDT concentrations were similar in Te Waihora eels when compared to international studies, while ΣPCB concentrations were orders of magnitude less. This study highlights two valid, but differing, approaches to assessment of risk. While the US EPA-based risk assessment illustrated a small but increased risk in consumption of most mahinga kai species from Te Waihora catchment - no FSANZ regulatory limits were exceeded. It is important to note that although based on sound scientific principles, the setting of FSANZ regulatory limits is not as scientifically transparent as the US EPA risk assessment procedure. Comparisons between regulatory limits and consumption limits suggest that New Zealand regulatory bodies use a less conservative risk profile than the US EPA risk assessment when setting their maximum limits. This report is concerned with contaminants that are a long-term (chronic) risk to human health. As such, the contaminants analysed in this risk assessment are environmentally persistent, have a tendency to bioaccumulate in biota and are known (or suspected) to be toxic to humans. This study has significantly increased understanding of risks associate with consumption of kai from Te Waihora. It presents the results of a preliminary human health risk assessment that is based on relatively few samples collected across a large variety of mahinga kai species and a broad spatial area.

Samples of oysters from multiple sites in the Manukau Harbour and transplanted mussels from multiple sites in Auckland estuaries and Waitemata Harbour were analysed for %lipid, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Analytical data for oysters and mussels were presented along with analytical procedures, methods and a quality assurance summary. The report includes lipid-normalised data sets of selected contaminants for comparison with earlier data sets.

Samples of oysters from multiple sites in the Manukau Harbour and transplanted mussels from multiple sites in Auckland estuaries and Waitemata Harbour were analysed for %lipid, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Analytical data for oysters and mussels were presented along with analytical procedures, methods and a quality assurance summary. The report includes lipid-normalised data sets of selected contaminants for comparison with earlier data sets.

Samples of oysters from multiple sites in the Manukau Harbour and transplanted mussels from multiple sites in Auckland estuaries and Waitemata Harbour were analysed for %lipid, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Analytical data for oysters and mussels were presented along with analytical procedures, methods and a quality assurance summary. The report includes lipid-normalised data sets of selected contaminants for comparison with earlier data sets. Oysters data set & Mussels data set are held in separate locations.

Samples of oysters from multiple sites in the Manukau Harbour and transplanted mussels from multiple sites in Auckland estuaries and Waitemata Harbour were analysed for %lipid, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Analytical data for oysters and mussels were presented along with analytical procedures, methods and a quality assurance summary. The report includes lipid-normalised data sets of selected contaminants for comparison with earlier data sets.

Samples of oysters from multiple sites in the Manukau Harbour and transplanted mussels from multiple sites in Auckland estuaries and Waitemata Harbour were analysed for %lipid, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Analytical data for oysters and mussels were presented along with analytical procedures, methods and a quality assurance summary. The report includes lipid-normalised data sets of selected contaminants for comparison with earlier data sets.

Samples of oysters from multiple sites in the Manukau Harbour and transplanted mussels from multiple sites in Auckland estuaries and Waitemata Harbour were analysed for %lipid, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Analytical data for oysters and mussels were presented along with analytical procedures, methods and a quality assurance summary. The report includes lipid-normalised data sets of selected contaminants for comparison with earlier data sets.