title: Hauraki Gulf sedimentation: Unintended consequences of flood protection

authors: de Lange, Willem P.

abstract: The Universities of Waikato and Bremen have examined sedimentation in the Hauraki Gulf, focussing on the sediment discharges from the Coromandel Peninsula and the Waihou/Ohinemuri river systems, to assess whether anthropic land-use changes over the last millennium have resulted in increased sedimentation rates. Previous studies identified increased sedimentation due to burning of vegetation following Polynesian settlement, and Kauri logging, mining and forest clearance following European settlement. Most studies attribute the highest sedimentation rates to European settlement. This paper considers the results of investigations of depocenters in the central Hauraki Gulf, Southern Firth of Thames, and Coromandel Harbour, as well as the sediment pathway along the Ohinemuri and Waihou Rivers from mining areas of the southern Coromandel Peninsula to the Hauraki Gulf. Contrary to expectations, the central Hauraki Gulf was found to consist of palimpsest fluvial and biogenic marine deposits, with minor Holocene sedimentation lacking a clear anthropic signal. The shallower depocenters contain thicker sequences of Holocene sediments, with high spatial variability. Areas with clear anthropic signals were those proximal to potential sources. Commonly there was a significant time gap between the palynological indications of European settlement and changes in metal concentrations or inferred sedimentation rates, which was inconsistent with historical records suggesting land disturbance was contemporary with settlement. Gold mining in the southern Coromandel Peninsula generated tailings that were deposited into the Ohinemuri River. Initially the Ohinemuri River aggraded and annual floods deposited tailings on the floodplains, predominantly between the Waihou and Ohinemuri Rivers south of Paeroa. Since 1910, the floodplains have progressively been drained and protected by stopbanks constructed from sediment dredged from the beds of rivers and canals, and intertidal flats; with the final major scheme being completed in 1972. Metal concentrations in surficial sediments indicate most tailings have been deposited on floodplains upstream of Paeroa, with little evidence of transport downstream of the Waihou/Ohinemuri confluence. Since the completion of the stopbanks major floods have predominantly discharged sediment into the Firth of Thames, instead of onto the floodplains. The progressive removal of the floodplains as potential depositional sites coincides with the documented expansion of mudflats and mangrove in the southern Firth of Thames. This may also account for the delayed onset of a significant anthropic signal in the Firth of Thames depocenter.

text: Hauraki Gulf sedimentation: Unintended consequences of flood protection The Universities of Waikato and Bremen have examined sedimentation in the Hauraki Gulf, focussing on the sediment discharges from the Coromandel Peninsula and the Waihou/Ohinemuri river systems, to assess whether anthropic land-use changes over the last millennium have resulted in increased sedimentation rates. Previous studies identified increased sedimentation due to burning of vegetation following Polynesian settlement, and Kauri logging, mining and forest clearance following European settlement. Most studies attribute the highest sedimentation rates to European settlement. This paper considers the results of investigations of depocenters in the central Hauraki Gulf, Southern Firth of Thames, and Coromandel Harbour, as well as the sediment pathway along the Ohinemuri and Waihou Rivers from mining areas of the southern Coromandel Peninsula to the Hauraki Gulf. Contrary to expectations, the central Hauraki Gulf was found to consist of palimpsest fluvial and biogenic marine deposits, with minor Holocene sedimentation lacking a clear anthropic signal. The shallower depocenters contain thicker sequences of Holocene sediments, with high spatial variability. Areas with clear anthropic signals were those proximal to potential sources. Commonly there was a significant time gap between the palynological indications of European settlement and changes in metal concentrations or inferred sedimentation rates, which was inconsistent with historical records suggesting land disturbance was contemporary with settlement. Gold mining in the southern Coromandel Peninsula generated tailings that were deposited into the Ohinemuri River. Initially the Ohinemuri River aggraded and annual floods deposited tailings on the floodplains, predominantly between the Waihou and Ohinemuri Rivers south of Paeroa. Since 1910, the floodplains have progressively been drained and protected by stopbanks constructed from sediment dredged from the beds of rivers and canals, and intertidal flats; with the final major scheme being completed in 1972. Metal concentrations in surficial sediments indicate most tailings have been deposited on floodplains upstream of Paeroa, with little evidence of transport downstream of the Waihou/Ohinemuri confluence. Since the completion of the stopbanks major floods have predominantly discharged sediment into the Firth of Thames, instead of onto the floodplains. The progressive removal of the floodplains as potential depositional sites coincides with the documented expansion of mudflats and mangrove in the southern Firth of Thames. This may also account for the delayed onset of a significant anthropic signal in the Firth of Thames depocenter.

year: 2018

title: Natural history, conservation and health: Scottish-trained doctors in New Zealand, 1790–1920s

authors: Beattie, James John

subjects: natural history

abstract: This article considers the nexus between environment, health and colonial development through the migration, and visits, of Scottish-educated doctors to New Zealand. In arguing for the importance of local social, environmental and economic factors to explain their changing prominence within, in particular, the field of natural history, this article enriches and in some cases modifies the work of Richard Grove and John M. MacKenzie.

text: Natural history, conservation and health: Scottish-trained doctors in New Zealand, 1790–1920s This article considers the nexus between environment, health and colonial development through the migration, and visits, of Scottish-educated doctors to New Zealand. In arguing for the importance of local social, environmental and economic factors to explain their changing prominence within, in particular, the field of natural history, this article enriches and in some cases modifies the work of Richard Grove and John M. MacKenzie.

year: 2011

title: Evaluation of Rongo Atea: Alcohol and Other Drug Treatment Centre for Adolescents

authors: Paki, Helen Mary

subjects: Alcohol

abstract: Abstract Rongo Ātea is a residential abstinence-based Kaupapa Māori alcohol and other drug programme accommodating youth between the ages of 13 and 17. This evaluation investigates the role that staff play at Rongo Ātea along with a number of other factors including the physical environment; stages of change; programme implementation and aftercare. As a Kaupapa Māori programme, the role of how culture and identity can influence positive change is also explored along with the development of a youth-focused approach. I utilised a three phase framework borrowed from the work of Mason Durie (2008) to organise themes. These three phases, which Durie (2008) based on marae encounters, include Whakapiri (Engagement); Whakamarama (Enlightenment); and Whakamana (Empowerment) as they aptly reflect a three phase intervention approach: detoxification and early programme engagement; learning and development through ongoing programme commitment; and post treatment outcomes and aftercare. The data collection phase of this evaluation took place in 2006 and was initiated by the manager of Rongo Ātea who requested an evaluation to identify programme strengths and limitations from the perspectives of staff and students, and to make recommendations to Rongo Ātea that would assist with further programme developments. I utilised a collaborative and participatory approach (Bishop, 1996; Patton, 1990). Kaupapa Māori research principles were reflected in the use of ‘kanohi kitea’— face to face contact (Smith, 1999). With appropriate training and management support, staff could have a greater influence on programme outcomes. Evaluation findings suggest that drug and alcohol intervention and treatment for young people in New Zealand is significantly under-resourced, particularly in the areas of detoxification and aftercare. To be effective, residential treatment programmes should consist of a three stage programme covering detoxification; treatment; and aftercare incorporating an integrated approach. A greater emphasis on working with whānau alongside the young person is recommended.

text: Evaluation of Rongo Atea: Alcohol and Other Drug Treatment Centre for Adolescents Abstract Rongo Ātea is a residential abstinence-based Kaupapa Māori alcohol and other drug programme accommodating youth between the ages of 13 and 17. This evaluation investigates the role that staff play at Rongo Ātea along with a number of other factors including the physical environment; stages of change; programme implementation and aftercare. As a Kaupapa Māori programme, the role of how culture and identity can influence positive change is also explored along with the development of a youth-focused approach. I utilised a three phase framework borrowed from the work of Mason Durie (2008) to organise themes. These three phases, which Durie (2008) based on marae encounters, include Whakapiri (Engagement); Whakamarama (Enlightenment); and Whakamana (Empowerment) as they aptly reflect a three phase intervention approach: detoxification and early programme engagement; learning and development through ongoing programme commitment; and post treatment outcomes and aftercare. The data collection phase of this evaluation took place in 2006 and was initiated by the manager of Rongo Ātea who requested an evaluation to identify programme strengths and limitations from the perspectives of staff and students, and to make recommendations to Rongo Ātea that would assist with further programme developments. I utilised a collaborative and participatory approach (Bishop, 1996; Patton, 1990). Kaupapa Māori research principles were reflected in the use of ‘kanohi kitea’— face to face contact (Smith, 1999). With appropriate training and management support, staff could have a greater influence on programme outcomes. Evaluation findings suggest that drug and alcohol intervention and treatment for young people in New Zealand is significantly under-resourced, particularly in the areas of detoxification and aftercare. To be effective, residential treatment programmes should consist of a three stage programme covering detoxification; treatment; and aftercare incorporating an integrated approach. A greater emphasis on working with whānau alongside the young person is recommended.

year: 2010