title: The presence, speciation, and movement of arsenic in Lake Tarawera

authors: Cochrane, Kirstie-Lee May Nicole

subjects: Arsenic, Lake Tarawera, rhizons

abstract: Arsenic is a naturally occurring element with potential toxicity to humans depending on concentration and chemical state. Contamination of freshwater environments by arsenic has been seen globally, occurring through both natural and anthropogenic sources. This thesis explores the presence, speciation, and movement of arsenic within Lake Tarawera, including the related physical and biogeochemical processes that control the movement and state of arsenic within the water body and from inlet sources. 
Lake Tarawera, in the Bay of Plenty Region, North Island, New Zealand is a large deep-water lake in an active volcanic region. Field measurements taken from Lake Tarawera were targeted towards a known localised geothermal area to explore spatial heterogeneity. The results show how the monomictic cycling regime of Lake Tarawera contributes to the retention of arsenic in the water column through increasing concentrations of benthic arsenic during the period of stratification across five open-water sites (196% difference between surface and benthic water As concentrations in March 2020), and homogenous distribution through winter overturning (10% maximum difference in As concentrations, statistically insignificant). The physical and chemical conditions of the lake (temperature and pH) and high solubility of arsenic retain dissolved species in the water column. Oxygen depletion is observed in the deepest part of the lake (2.3 mg L⁻¹ at 79 m depth) which corresponds with increased benthic arsenic concentrations (126 µg L⁻¹).  
Inlets in the southern arm of the lake (Wairua Arm) are higher sources of arsenic into the water body than inlets in the main body of the lake, with arsenic concentrations from all sampled Wairua Arm inlets exceeding the World Heath Organisation 10 µg L⁻¹ drinking water standard; dissolved concentrations ranging from 41.0-947 µg L⁻¹. One high volume waterfall (Rotomahana WateArsenic is a naturally occurring element with potential toxicity to humans depending on concentration and chemical state. Contamination of freshwater environments by arsenic has been seen globally, occurring through both natural and anthropogenic sources. This thesis explores the presence, speciation, and movement of arsenic within Lake Tarawera, including the related physical and biogeochemical processes that control the movement and state of arsenic within the water body and from inlet sources.  Lake Tarawera, in the Bay of Plenty Region, North Island, New Zealand is a large deep-water lake in an active volcanic region. Field measurements taken from Lake Tarawera were targeted towards a known localised geothermal area to explore spatial heterogeneity. The results show how the monomictic cycling regime of Lake Tarawera contributes to the retention of arsenic in the water column through increasing concentrations of benthic arsenic during the period of stratification across five open-water sites (196% difference between surface and benthic water As concentrations in March 2020), and homogenous distribution through winter overturning (10% maximum difference in As concentrations, statistically insignificant). The physical and chemical conditions of the lake (temperature and pH) and high solubility of arsenic retain dissolved species in the water column. Oxygen depletion is observed in the deepest part of the lake (2.3 mg L⁻¹ at 79 m depth) which corresponds with increased benthic arsenic concentrations (126 µg L⁻¹).  Inlets in the southern arm of the lake (Wairua Arm) are higher sources of arsenic into the water body than inlets in the main body of the lake, with arsenic concentrations from all sampled Wairua Arm inlets exceeding the World Heath Organisation 10 µg L⁻¹ drinking water standard; dissolved concentrations ranging from 41.0-947 µg L⁻¹. One high volume waterfall (Rotomahana Waterfall) provides a per second arsenic loading of 16,400 ± 2,660 µg As s⁻¹. The more toxic form of arsenic (AsIII) was only detected in one instance, from a warm water stream inlet. Iron and manganese concentrations and the partitioning of these transition metals indicates the ratio of arsenic to these binding elements is not of the right order of  magnitude to remove substantial arsenic from the water column, as dissolved arsenic concentrations exceed that of both iron and manganese. 
Water isotope ratios and dissolved arsenic concentrations from Rotomahana Waterfall show a complicated mixing regime, including influences such as wind, rainfall, other inlets, and opposing water flows coming from the main water and the high flow waterfall. High temperature and low flow waters from Hot Water Beach demonstrates the influence of inlet water temperature because they alter the movement and concentrations of arsenic heading out towards the open-water inlets. The high temperature of Hot Water Beach creates a localised area of thermal stratification, which causes surface mixing and dilution of the inlet waters with the nearest open-water site. Mixing then occurs with depth closer to the open-water site, passed the point of the hot water induced thermocline. These targeted samples highlight how well arsenic is diluted and buffered by such a large volume of water, and demonstrate the importance of stratification, temperature, and flow rate on the movement of As.  
Laboratory and field studies attempted to minimise oxygen introduction to pore water samples using rhizons (pore water filters) and vacutainers. Arsenic speciation was retained in field samples in the vacutainers for up to three months, with concentrations of up to 2,230 µg L-1 of AsIII measured; this result which led to laboratory experiments on the long-term storage and retention of AsIII. However, the data from these laboratory studies were inconclusive for over-time analyses of two experiments; days 2, 26, and 55 after sample spiking for the first experiment, and days 2 and 29 for the second experiment. Vacutainers and rhizons extracted pore waters in-situ in attempt to minimise oxygen introduction to low dissolved oxygen samples; however, the methodology for long-term storage requires further research.  
Speciation of arsenic occurs in the sediments due to the highly anoxic environment, with pore water AsIII concentrations ranging exceeding 2,000 µg L⁻¹ in the surface sediments and decreasing with depth. Sediment concentrations show distinct accumulation boundaries which are indicative of redox boundaries over time. rfall) provides a per second arsenic loading of 16,400 ± 2,660 µg As s⁻¹. The more toxic form of arsenic (AsIII) was only detected in one instance, from a warm water stream inlet. Iron and manganese concentrations and the partitioning of these transition metals indicates the ratio of arsenic to these binding elements is not of the right order of  magnitude to remove substantial arsenic from the water column, as dissolved arsenic concentrations exceed that of both iron and manganese. Water isotope ratios and dissolved arsenic concentrations from Rotomahana Waterfall show a complicated mixing regime, including influences such as wind, rainfall, other inlets, and opposing water flows coming from the main water and the high flow waterfall. High temperature and low flow waters from Hot Water Beach demonstrates the influence of inlet water temperature because they alter the movement and concentrations of arsenic heading out towards the open-water inlets. The high temperature of Hot Water Beach creates a localised area of thermal stratification, which causes surface mixing and dilution of the inlet waters with the nearest open-water site. Mixing then occurs with depth closer to the open-water site, passed the point of the hot water induced thermocline. These targeted samples highlight how well arsenic is diluted and buffered by such a large volume of water, and demonstrate the importance of stratification, temperature, and flow rate on the movement of As.  Laboratory and field studies attempted to minimise oxygen introduction to pore water samples using rhizons (pore water filters) and vacutainers. Arsenic speciation was retained in field samples in the vacutainers for up to three months, with concentrations of up to 2,230 µg L⁻¹ of AsIII measured; this result which led to laboratory experiments on the long-term storage and retention of AsIII. However, the data from these laboratory studies were inconclusive for over-time analyses of two experiments; days 2, 26, and 55 after sample spiking for the first experiment, and days 2 and 29 for the second experiment. Vacutainers and rhizons extracted pore waters in-situ in attempt to minimise oxygen introduction to low dissolved oxygen samples; however, the methodology for long-term storage requires further research.  Speciation of arsenic occurs in the sediments due to the highly anoxic environment, with pore water AsIII concentrations ranging exceeding 2,000 µg L⁻¹ in the surface sediments and decreasing with depth. Sediment concentrations show distinct accumulation boundaries which are indicative of redox boundaries over time.

text: The presence, speciation, and movement of arsenic in Lake Tarawera Arsenic is a naturally occurring element with potential toxicity to humans depending on concentration and chemical state. Contamination of freshwater environments by arsenic has been seen globally, occurring through both natural and anthropogenic sources. This thesis explores the presence, speciation, and movement of arsenic within Lake Tarawera, including the related physical and biogeochemical processes that control the movement and state of arsenic within the water body and from inlet sources. 
Lake Tarawera, in the Bay of Plenty Region, North Island, New Zealand is a large deep-water lake in an active volcanic region. Field measurements taken from Lake Tarawera were targeted towards a known localised geothermal area to explore spatial heterogeneity. The results show how the monomictic cycling regime of Lake Tarawera contributes to the retention of arsenic in the water column through increasing concentrations of benthic arsenic during the period of stratification across five open-water sites (196% difference between surface and benthic water As concentrations in March 2020), and homogenous distribution through winter overturning (10% maximum difference in As concentrations, statistically insignificant). The physical and chemical conditions of the lake (temperature and pH) and high solubility of arsenic retain dissolved species in the water column. Oxygen depletion is observed in the deepest part of the lake (2.3 mg L⁻¹ at 79 m depth) which corresponds with increased benthic arsenic concentrations (126 µg L⁻¹).  
Inlets in the southern arm of the lake (Wairua Arm) are higher sources of arsenic into the water body than inlets in the main body of the lake, with arsenic concentrations from all sampled Wairua Arm inlets exceeding the World Heath Organisation 10 µg L⁻¹ drinking water standard; dissolved concentrations ranging from 41.0-947 µg L⁻¹. One high volume waterfall (Rotomahana WateArsenic is a naturally occurring element with potential toxicity to humans depending on concentration and chemical state. Contamination of freshwater environments by arsenic has been seen globally, occurring through both natural and anthropogenic sources. This thesis explores the presence, speciation, and movement of arsenic within Lake Tarawera, including the related physical and biogeochemical processes that control the movement and state of arsenic within the water body and from inlet sources.  Lake Tarawera, in the Bay of Plenty Region, North Island, New Zealand is a large deep-water lake in an active volcanic region. Field measurements taken from Lake Tarawera were targeted towards a known localised geothermal area to explore spatial heterogeneity. The results show how the monomictic cycling regime of Lake Tarawera contributes to the retention of arsenic in the water column through increasing concentrations of benthic arsenic during the period of stratification across five open-water sites (196% difference between surface and benthic water As concentrations in March 2020), and homogenous distribution through winter overturning (10% maximum difference in As concentrations, statistically insignificant). The physical and chemical conditions of the lake (temperature and pH) and high solubility of arsenic retain dissolved species in the water column. Oxygen depletion is observed in the deepest part of the lake (2.3 mg L⁻¹ at 79 m depth) which corresponds with increased benthic arsenic concentrations (126 µg L⁻¹).  Inlets in the southern arm of the lake (Wairua Arm) are higher sources of arsenic into the water body than inlets in the main body of the lake, with arsenic concentrations from all sampled Wairua Arm inlets exceeding the World Heath Organisation 10 µg L⁻¹ drinking water standard; dissolved concentrations ranging from 41.0-947 µg L⁻¹. One high volume waterfall (Rotomahana Waterfall) provides a per second arsenic loading of 16,400 ± 2,660 µg As s⁻¹. The more toxic form of arsenic (AsIII) was only detected in one instance, from a warm water stream inlet. Iron and manganese concentrations and the partitioning of these transition metals indicates the ratio of arsenic to these binding elements is not of the right order of  magnitude to remove substantial arsenic from the water column, as dissolved arsenic concentrations exceed that of both iron and manganese. 
Water isotope ratios and dissolved arsenic concentrations from Rotomahana Waterfall show a complicated mixing regime, including influences such as wind, rainfall, other inlets, and opposing water flows coming from the main water and the high flow waterfall. High temperature and low flow waters from Hot Water Beach demonstrates the influence of inlet water temperature because they alter the movement and concentrations of arsenic heading out towards the open-water inlets. The high temperature of Hot Water Beach creates a localised area of thermal stratification, which causes surface mixing and dilution of the inlet waters with the nearest open-water site. Mixing then occurs with depth closer to the open-water site, passed the point of the hot water induced thermocline. These targeted samples highlight how well arsenic is diluted and buffered by such a large volume of water, and demonstrate the importance of stratification, temperature, and flow rate on the movement of As.  
Laboratory and field studies attempted to minimise oxygen introduction to pore water samples using rhizons (pore water filters) and vacutainers. Arsenic speciation was retained in field samples in the vacutainers for up to three months, with concentrations of up to 2,230 µg L-1 of AsIII measured; this result which led to laboratory experiments on the long-term storage and retention of AsIII. However, the data from these laboratory studies were inconclusive for over-time analyses of two experiments; days 2, 26, and 55 after sample spiking for the first experiment, and days 2 and 29 for the second experiment. Vacutainers and rhizons extracted pore waters in-situ in attempt to minimise oxygen introduction to low dissolved oxygen samples; however, the methodology for long-term storage requires further research.  
Speciation of arsenic occurs in the sediments due to the highly anoxic environment, with pore water AsIII concentrations ranging exceeding 2,000 µg L⁻¹ in the surface sediments and decreasing with depth. Sediment concentrations show distinct accumulation boundaries which are indicative of redox boundaries over time. rfall) provides a per second arsenic loading of 16,400 ± 2,660 µg As s⁻¹. The more toxic form of arsenic (AsIII) was only detected in one instance, from a warm water stream inlet. Iron and manganese concentrations and the partitioning of these transition metals indicates the ratio of arsenic to these binding elements is not of the right order of  magnitude to remove substantial arsenic from the water column, as dissolved arsenic concentrations exceed that of both iron and manganese. Water isotope ratios and dissolved arsenic concentrations from Rotomahana Waterfall show a complicated mixing regime, including influences such as wind, rainfall, other inlets, and opposing water flows coming from the main water and the high flow waterfall. High temperature and low flow waters from Hot Water Beach demonstrates the influence of inlet water temperature because they alter the movement and concentrations of arsenic heading out towards the open-water inlets. The high temperature of Hot Water Beach creates a localised area of thermal stratification, which causes surface mixing and dilution of the inlet waters with the nearest open-water site. Mixing then occurs with depth closer to the open-water site, passed the point of the hot water induced thermocline. These targeted samples highlight how well arsenic is diluted and buffered by such a large volume of water, and demonstrate the importance of stratification, temperature, and flow rate on the movement of As.  Laboratory and field studies attempted to minimise oxygen introduction to pore water samples using rhizons (pore water filters) and vacutainers. Arsenic speciation was retained in field samples in the vacutainers for up to three months, with concentrations of up to 2,230 µg L⁻¹ of AsIII measured; this result which led to laboratory experiments on the long-term storage and retention of AsIII. However, the data from these laboratory studies were inconclusive for over-time analyses of two experiments; days 2, 26, and 55 after sample spiking for the first experiment, and days 2 and 29 for the second experiment. Vacutainers and rhizons extracted pore waters in-situ in attempt to minimise oxygen introduction to low dissolved oxygen samples; however, the methodology for long-term storage requires further research.  Speciation of arsenic occurs in the sediments due to the highly anoxic environment, with pore water AsIII concentrations ranging exceeding 2,000 µg L⁻¹ in the surface sediments and decreasing with depth. Sediment concentrations show distinct accumulation boundaries which are indicative of redox boundaries over time.

year: 2020

title: The role of women in nation-building: Rocking the Boat at the Risk of making it Capsize?

authors: Williamson, Myra Elsie Jane Bell

abstract: I have been in exile for a long time, and I was amazed at the resilience, intelligence, strength and ability of the Afghan women that I met who came from inside the country and around the world. These women, I promise, can rebuild the country with no problem.1 In this paper I propose to examine the role played by women in post-conflict scenarios, especially with regards to peace-keeping and nation building. I would like to begin with a general statement about the important and equal role of women in society, a principle which is enshrined in both international human rights documents such as the Universal Declaration of Human Rights and the International Covenant on Civil and Political Rights. It is also a principle that is accepted by the major religions, including Islam. The proposed title of the paper takes its inspiration from the following quote: Few policymakers responsible for nation-building would argue against the ultimate goal of establishing equitable, democratic and egalitarian societies in which the human rights of women are respected. Many however, express the fear that pursuing that goal “too soon” may rock the boat, and that in dealing with a boat so shaky that it may capsize anyway, you just can’t take the risk. (Bernard et al, 2008: 3) This paper seeks to determine what role women should play in postconflict scenarios, without “capsizing the boat”. It questions to what degree women’s involvement must be postponed in order to first “stabilize the situation”. Some would argue that given the various advantages in women’s involvement sooner rather than later, that their involvement ought not to be postponed.1 The paper will particularly draw upon the involvement of women in Afghanistan. However, Afghanistan itself provides examples of the danger and difficulty of promoting women’s involvement in nation-building. For example, as recently as Sunday 29th September 2008 it was reported that an iconic Afghan policewoman, Malalai Kakar, had been shot and killed, and that the Taliban had claimed responsibility for her death.2 This was not the first instance of a woman in Afghanistan’s post-2001 police force being directly targeted for assassination. The question these incidents raise is whether an emphasis on promoting the participation of women in the Afghani police-force is premature: is this an example of “rocking the boat” or is this all part and parcel of nation-building? The proposed broad outline for the paper is as follows: Introduction and basic premises: The equality of women and the role of women in society: general legal, social and religious principles; Women and nation-building: definitions, general principles, international documents and statistics; Afghanistan: processes and problems – historical context and modern issues; Conclusion: recommendations for Afghanistan in particular and for women in nation-building in a more general sense.

text: The role of women in nation-building: Rocking the Boat at the Risk of making it Capsize? I have been in exile for a long time, and I was amazed at the resilience, intelligence, strength and ability of the Afghan women that I met who came from inside the country and around the world. These women, I promise, can rebuild the country with no problem.1 In this paper I propose to examine the role played by women in post-conflict scenarios, especially with regards to peace-keeping and nation building. I would like to begin with a general statement about the important and equal role of women in society, a principle which is enshrined in both international human rights documents such as the Universal Declaration of Human Rights and the International Covenant on Civil and Political Rights. It is also a principle that is accepted by the major religions, including Islam. The proposed title of the paper takes its inspiration from the following quote: Few policymakers responsible for nation-building would argue against the ultimate goal of establishing equitable, democratic and egalitarian societies in which the human rights of women are respected. Many however, express the fear that pursuing that goal “too soon” may rock the boat, and that in dealing with a boat so shaky that it may capsize anyway, you just can’t take the risk. (Bernard et al, 2008: 3) This paper seeks to determine what role women should play in postconflict scenarios, without “capsizing the boat”. It questions to what degree women’s involvement must be postponed in order to first “stabilize the situation”. Some would argue that given the various advantages in women’s involvement sooner rather than later, that their involvement ought not to be postponed.1 The paper will particularly draw upon the involvement of women in Afghanistan. However, Afghanistan itself provides examples of the danger and difficulty of promoting women’s involvement in nation-building. For example, as recently as Sunday 29th September 2008 it was reported that an iconic Afghan policewoman, Malalai Kakar, had been shot and killed, and that the Taliban had claimed responsibility for her death.2 This was not the first instance of a woman in Afghanistan’s post-2001 police force being directly targeted for assassination. The question these incidents raise is whether an emphasis on promoting the participation of women in the Afghani police-force is premature: is this an example of “rocking the boat” or is this all part and parcel of nation-building? The proposed broad outline for the paper is as follows: Introduction and basic premises: The equality of women and the role of women in society: general legal, social and religious principles; Women and nation-building: definitions, general principles, international documents and statistics; Afghanistan: processes and problems – historical context and modern issues; Conclusion: recommendations for Afghanistan in particular and for women in nation-building in a more general sense.

year: 2019

title: Examining the effects of Ki-o-Rahi on the development of fundamental movement skills by children in Aotearoa New Zealand

authors: Daveta, Wiliame

subjects: fundamental movement skills

abstract: Children with poor fundamental movement skills might have challenges when engaging in activities that require specific skills to help them perform effectively. Development of those skills through targeted training has the potential to build the foundation for fundamental movement skills. This study examined whether Ki-o-Rahi can enhance learning fundamental movement skills (FMS) and cognitive and social skills in Aotearoa New Zealand children. A quasi-experimental pre-post design was conducted over 8 weeks with 86 primary school children from five separate classes that were allocated to treatment conditions via cluster sampling: two classes to the intervention group, two to the control group, and one to the legend-only control group. The intervention group learned the legend and played Ki-o-Rahi over 8 sessions, whereas the control groups continued with their regular physical activities, but only one of the control groups learned the legend. FMS were measured using the Test of Gross Motor Development—Third Edition (TGMD-3) and the Motor Assessment Battery for Children (MABC-2). Cognitive skills were measured using the Head-Toes-Knees-Shoulders test (HTKS), forward and backward digit span, and forward and backward corsi block. Researchers measured social skills using the Early Childhood Social Relationship with Peers (ECSRP) teacher-proxy questionnaire. The results demonstrated that the intervention and control group gained improvements in the FMS and social skills but not cognitive skills. The legend-only group showed no significant changes. The findings suggest that Ki-o-rahi can contribute to developing FMS, cognitive, and social skills in Aotearoa New Zealand children. Future research should consider extending the duration of the study to assess long-term effects and include a larger cohort of Pacific or Māori children to explore potential benefits of Ki-o-Rahi in greater depth.

text: Examining the effects of Ki-o-Rahi on the development of fundamental movement skills by children in Aotearoa New Zealand Children with poor fundamental movement skills might have challenges when engaging in activities that require specific skills to help them perform effectively. Development of those skills through targeted training has the potential to build the foundation for fundamental movement skills. This study examined whether Ki-o-Rahi can enhance learning fundamental movement skills (FMS) and cognitive and social skills in Aotearoa New Zealand children. A quasi-experimental pre-post design was conducted over 8 weeks with 86 primary school children from five separate classes that were allocated to treatment conditions via cluster sampling: two classes to the intervention group, two to the control group, and one to the legend-only control group. The intervention group learned the legend and played Ki-o-Rahi over 8 sessions, whereas the control groups continued with their regular physical activities, but only one of the control groups learned the legend. FMS were measured using the Test of Gross Motor Development—Third Edition (TGMD-3) and the Motor Assessment Battery for Children (MABC-2). Cognitive skills were measured using the Head-Toes-Knees-Shoulders test (HTKS), forward and backward digit span, and forward and backward corsi block. Researchers measured social skills using the Early Childhood Social Relationship with Peers (ECSRP) teacher-proxy questionnaire. The results demonstrated that the intervention and control group gained improvements in the FMS and social skills but not cognitive skills. The legend-only group showed no significant changes. The findings suggest that Ki-o-rahi can contribute to developing FMS, cognitive, and social skills in Aotearoa New Zealand children. Future research should consider extending the duration of the study to assess long-term effects and include a larger cohort of Pacific or Māori children to explore potential benefits of Ki-o-Rahi in greater depth.

year: 2024