title: Geological, hydrodynamic and biogeochemical variability of a New Zealand deep-water methane cold seep during an integrated three-year time-series study

authors: Law, C.S.

subjects: methane

abstract: Cold seeps are widely distributed on active and passive margins and display considerable temporal variability in terms of gas and fluid expulsion rates and volume, over scales of hours to days. To constrain this variability, two cold seeps, the North and South Tower, located at the Wairarapa Seep site on Opouawe Bank, Cook Strait, New Zealand, were monitored in an integrated geological and biogeochemical study during eight surveys between 2005 and 2008. To ensure sampling of the water column within the flare overlying the seeps the vessel was manoeuvred in response to the backscatter data from a hull-mounted 38 kHz single-beam echo-sounder. High methane concentrations (> 100 nmol l− 1) were found within 400–450 m-high flares at both sites, and within an 825 m-high flare at a newly identified seep, southeast of Pahaua Bank. Elevated bottom water methane was also found over newly identified mud volcanoes on the Campbell Bank, Cook Strait. The locations of the seeps appear to be structurally controlled with active methane vents occurring on anticlinal ridges and associated with a 30 m-high normal fault scarp on Opouawe Bank. Fluid flow is facilitated by sedimentary layer permeability properties, structural focusing and dilational fracturing on the crest of a large anticlinal ridge, cored by a seaward-verging reverse fault. The South Tower cold seep did not significantly influence bulk sediment and water column particulates and nutrients, although high bacterial biomass, productivity and methane oxidation rates were associated with elevated methane in the flare. The seep flares exhibited depleted δ13C–CH4 values (− 63 to − 70‰), characteristic of shallow biogenic gas sources. Incorporation of the δ13C–CH4 and CH4 concentration data in a mixing model, and comparison of the water residence time with methane oxidation rates, indicated that the primary fate of methane in the flare was dilution. The dissolved methane originating from the seeps was retained in the water column at depths > 700 m, with minimal contribution to atmospheric emissions, as confirmed by surface methane mapping. Nevertheless, the South Tower seep was a significant source of methane with a column-integrated burden below 700 m of 5.6 mmol m− 2, and an estimated annual emission of 0.5–1 × 106 mol CH4. The structural and tectonic setting of the Wairarapa Seep provides a useful analogue model for other convergent margin cold seeps on the Hikurangi Margin and elsewhere. This unique, three-year integrated study provided valuable insights into the linkage between geological structure and overlying water column biogeochemistry, and confirmed the value of this cold seep site for long-term monitoring.

text: Geological, hydrodynamic and biogeochemical variability of a New Zealand deep-water methane cold seep during an integrated three-year time-series study Cold seeps are widely distributed on active and passive margins and display considerable temporal variability in terms of gas and fluid expulsion rates and volume, over scales of hours to days. To constrain this variability, two cold seeps, the North and South Tower, located at the Wairarapa Seep site on Opouawe Bank, Cook Strait, New Zealand, were monitored in an integrated geological and biogeochemical study during eight surveys between 2005 and 2008. To ensure sampling of the water column within the flare overlying the seeps the vessel was manoeuvred in response to the backscatter data from a hull-mounted 38 kHz single-beam echo-sounder. High methane concentrations (> 100 nmol l− 1) were found within 400–450 m-high flares at both sites, and within an 825 m-high flare at a newly identified seep, southeast of Pahaua Bank. Elevated bottom water methane was also found over newly identified mud volcanoes on the Campbell Bank, Cook Strait. The locations of the seeps appear to be structurally controlled with active methane vents occurring on anticlinal ridges and associated with a 30 m-high normal fault scarp on Opouawe Bank. Fluid flow is facilitated by sedimentary layer permeability properties, structural focusing and dilational fracturing on the crest of a large anticlinal ridge, cored by a seaward-verging reverse fault. The South Tower cold seep did not significantly influence bulk sediment and water column particulates and nutrients, although high bacterial biomass, productivity and methane oxidation rates were associated with elevated methane in the flare. The seep flares exhibited depleted δ13C–CH4 values (− 63 to − 70‰), characteristic of shallow biogenic gas sources. Incorporation of the δ13C–CH4 and CH4 concentration data in a mixing model, and comparison of the water residence time with methane oxidation rates, indicated that the primary fate of methane in the flare was dilution. The dissolved methane originating from the seeps was retained in the water column at depths > 700 m, with minimal contribution to atmospheric emissions, as confirmed by surface methane mapping. Nevertheless, the South Tower seep was a significant source of methane with a column-integrated burden below 700 m of 5.6 mmol m− 2, and an estimated annual emission of 0.5–1 × 106 mol CH4. The structural and tectonic setting of the Wairarapa Seep provides a useful analogue model for other convergent margin cold seeps on the Hikurangi Margin and elsewhere. This unique, three-year integrated study provided valuable insights into the linkage between geological structure and overlying water column biogeochemistry, and confirmed the value of this cold seep site for long-term monitoring.

year: 2010

title: Nutrient and sediment loads from farm drains – fact sheet

authors: Tempero, Grant Wayne

abstract: Runoff from intensive agriculture has been identified as a major contributor to the decline of New Zealand's freshwater ecosystems. Excessive nutrient and sediment losses to lakes and rivers lead to reduced water clarity and quality, which in turn leads to reductions in biodiversity and amenity and aesthetic values.

text: Nutrient and sediment loads from farm drains – fact sheet Runoff from intensive agriculture has been identified as a major contributor to the decline of New Zealand's freshwater ecosystems. Excessive nutrient and sediment losses to lakes and rivers lead to reduced water clarity and quality, which in turn leads to reductions in biodiversity and amenity and aesthetic values.

year: 2015

title: Hā Ora: secondary care barriers and enablers to early diagnosis of lung cancer for Māori communities.

authors: Kidd, Jacquie

subjects: Barriers

abstract: BACKGROUND: Lung Cancer is the leading cause of cancer deaths in Aotearoa New Zealand. Māori communities in particular have higher incidence and mortality rates from Lung Cancer. Diagnosis of lung cancer at an early stage can allow for curative treatment. This project aimed to document the barriers to early diagnosis and treatment of lung cancer in secondary care for Māori communities. 
METHODS: This project used a kaupapa Māori approach. Nine community hui (focus groups) and nine primary healthcare provider hui were carried out in five rural localities in the Midland region. Community hui included cancer patients, whānau (families), and other community members. Healthcare provider hui comprised staff members at the local primary healthcare centre, including General Practitioners and nurses. Hui data were thematically analysed. 
RESULTS: Barriers and enablers to early diagnosis of lung cancer were categorised into two broad themes: Specialist services and treatment, and whānau journey. The barriers and enablers that participants experienced in specialist services and treatment related to access to care, engagement with specialists, communication with specialist services and cultural values and respect, whereas barriers and enablers relating to the whānau journey focused on agency and the impact on whānau. 
CONCLUSIONS: The study highlighted the need to improve communication within and across healthcare services, the importance of understanding the cultural needs of patients and whānau and a health system strategy that meets these needs. Findings also demonstrated the resilience of Māori and the active efforts of whānau as carers to foster health literacy in future generations.

text: Hā Ora: secondary care barriers and enablers to early diagnosis of lung cancer for Māori communities. BACKGROUND: Lung Cancer is the leading cause of cancer deaths in Aotearoa New Zealand. Māori communities in particular have higher incidence and mortality rates from Lung Cancer. Diagnosis of lung cancer at an early stage can allow for curative treatment. This project aimed to document the barriers to early diagnosis and treatment of lung cancer in secondary care for Māori communities. 
METHODS: This project used a kaupapa Māori approach. Nine community hui (focus groups) and nine primary healthcare provider hui were carried out in five rural localities in the Midland region. Community hui included cancer patients, whānau (families), and other community members. Healthcare provider hui comprised staff members at the local primary healthcare centre, including General Practitioners and nurses. Hui data were thematically analysed. 
RESULTS: Barriers and enablers to early diagnosis of lung cancer were categorised into two broad themes: Specialist services and treatment, and whānau journey. The barriers and enablers that participants experienced in specialist services and treatment related to access to care, engagement with specialists, communication with specialist services and cultural values and respect, whereas barriers and enablers relating to the whānau journey focused on agency and the impact on whānau. 
CONCLUSIONS: The study highlighted the need to improve communication within and across healthcare services, the importance of understanding the cultural needs of patients and whānau and a health system strategy that meets these needs. Findings also demonstrated the resilience of Māori and the active efforts of whānau as carers to foster health literacy in future generations.

year: 2021