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.
NIWA staff regularly take measurements at several hundred sites with a range of structures and installed equipment around New Zealand. Typically, these are hydrometric stations with small or large structures on streams and rivers, and climate stations with instruments on the ground or on masts. However there is also a range of other installations for various purposes. Some stations are owned by NIWA and some by our clients. Mostly we do not have any ownership or legal title but they are essentially under NIWA’s control from a workplace and safety responsibility perspective. (A few, such as sites on energy company property, are controlled by those companies and we often need express authorisation to enter the workplace.) This report provides a guide for hydrodynamic and climate station safety inspections for NIWA staff. Guidelines to prepare for inspection of a site. Guide to the checklist (the form): 1 Access 2 General 3 Mains power supply 4 Riverbank access 5 Structures 6 Ladders 7 Cableway 8 Across-river cables The appendices contain The Inspection Form, Identification of steel I-beam sizes and photographic examples of faults.
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.
Plant and Food Research engaged NIWA to design and implement a survey programme to monitor the effects of an experimental fish feeding operation on the benthic environment in Nelson Haven, to satisfy resource consent requirements. This was conducted to assess whether the feeding programme would adversely affect the local benthic environment, the survey focussed on measuring key indicators of organic enrichment. To do this, a range of sediment physicochemical parameters were characterised using benthic cores and sledding methods. Parameters included: sediment grain size, sediment organic content, sediment colour and smell, and redox potential of surficial sediment,and also biotic features including: the composition of animal communities living upon and within the sediments, and the distribution and abundance of macroalgae. This report describes the survey undertaken 8 months after the commencement of the fish feeding activity. Benthic and sediment data from 7 sites have been processed, checked, analysed, and summarised in the client report. Previous reports in this time series are: Brown, S. N. (2014a). Wildfish 2030: Benthic Monitoring Baseline Survey. Report prepared for Plant and Food Research Ltd. NIWA Client Report No. NEL2014-013. 18 p. Brown, S. N. (2014b). Wildfish 2030: Benthic Monitoring Survey – First post baseline survey. Report prepared for Plant and Food Research Ltd. NIWA Client Report No. NEL2014-021.18 p.
To satisfy resource consent conditions at a mussel farm site near Beacon Rock and Blind Bay, Banks Peninsula, Sanford LTD commissioned NIWA to conduct a benthic monitoring survey. Sampling for this project included a benthic grab and benthic sled to obtain samples to describe sediment physicochemical characteristics, and benthic assemblages at sample sites established along transects extending to the northwest, north and east of the farm block.
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.
Just Mussels LTD engaged NIWA to complete a benthic survey and assessment as part of a coastal permit application for an extension to marine farm 8321, in Wilson Bay, Pelorus Sound. This assessment comprised side-scan-sonar swath mapping of sites to characterise seabed topography, photoquadrats of the seabed to ground-truth the side-scans, samples of epifauana, diver observations and core sampling. The report indicated that the proposed extension is not expected to cause any significant adverse ecological effects. The ecological effects of farming the proposed additional mollusc species are likely to be no greater than the effects of farming green mussels. Farming of the algal species (as proposed) is unlikely to have any significant ecological effects. The report identifies a dense population of burrowing shrimp (Upogebia hirtifrons) adjacent to the inshore boundary of the site. However, the report notes that there is unlikely to be any significant detrimental effect of the proposed extension to the shrimp burrow habitat.
The reports describes: 1. The methods of sampling & analyses used based upon questionnaires completed by iwi members. 2. Results for bioaccumulative contaminants, e.g. DDTs, PCBs, heavy metals, arsenic. 3. A discussion of the significance of these results to respective Iwi. 4. Recommendations for future research. Questionnaires were used to survey Te Arawa iwi members about their past and present consumption rates of traditional kai species. Hair samples were also collected from Te Arawa participants to assess possible exposure to mercury, a highly accumulative contaminant. Fish and/or shellfish (including longfin or shortfin eel, rainbow or brown trout, koura, pipi, mussel, flounder and kakahi) and watercress samples were gathered from multiple important harvesting sites in the different regions, and tested to assess their bioaccumulative contaminant levels. Aquatic sediments, which are known to concentrate contaminants on organic material, were sampled from these locations as well. Analytical data for fish, shellfish and sediment samples was collected for a range of organochlorine compounds, including DDT (historically used as a pesticide), chlordane (a pesticide) and dieldrin (an insecticide), arsenic (As),and heavy metals e.g. cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni) and zinc (Zn). Eel and/or trout fillets were also analysed for selected polychlorinated biphenyls (PCBs). Watercress was analysed for heavy metals and arsenic only. Highest total DDT (ΣDDT) concentrations in Te Arawa rohe were detected in trout from the Upper Puarenga Stream site whereas the concentrations of ΣDDT were generally much lower in eels. Mercury concentrations in Te Arawa Rohe were generally highest in trout tissue, with the highest concentrations found at the Upper Puarenga Stream. Arsenic, cadmium and nickel concentrations were highest in pipis and mussels collected from the Maketu site and copper concentrations were higher in koura than any other species, with the highest concentrations ranging in Lake Rotokakahi and in Lake Okareka in Te Arawa rohe. The average concentration of mercury in the hair samples of Te Arawa iwi was three times higher than the study reference group and twice that of New Zealander’s who consume 1-4 meals of fish per month. The low number of Te Arawa responders in this study meant it was not possible to analyse potential links with consumption of wild kai. The ANZECC interim sediment quality guideline (ISQG) low values in Te Arawa rohe were exceeded for arsenic and mercury at 55 percent of sites sampled and for cadmium at 10 percent of the sites. The ANZECC ISQG high guideline value for arsenic was exceeded at 15 percent of sites and at 25 percent of sites for mercury. Based on the ratio of sediment to tissue metal concentrations, bioaccumulation “hotspots” were identified at Maketu (for shellfish), the Lower Kaituna site (for whitebait) and the Ohau Channel (for smelt). This health risk assessment using local iwi data on meal size and weekly consumption showed that mercury and arsenic were the primary contaminants of concern for Te Arawa iwi. The risk assessment indicated that there may be an increased risk to members of the Te Arawa iwi from long-term consumption of trout, pipi, mussel and watercress. Current consumption rates for eel are also close to exceeding safe levels. If kai was mostly gathered at the more contaminated sites then a significant risk exists when eating trout, eel and pipi.