title: The influence of river plume discharge and winds on sediment transport into a coastal mangrove environment

authors: Vundavilli, Hemanth

abstract: We investigate how the physical forcing factors of river discharge and winds affect sediment delivery to, and retention within, mangrove-lined coastal regions. We use an idealized numerical model, broadly similar to the Firth of Thames deltaic system in New Zealand, to isolate and explore the underlying processes without some of the complexities of the real system. Total sediment transport and the relative contributions of riverine and bed-sourced sediment into the forest are assessed using a transect along the edge of the forest region. The model results demonstrate that both river discharge and winds alter the distribution of sediment transport, and that the spatial patterns relate to different regions of the river plume. At the river mouth (the near-field region), irrespective of the discharge employed, sediment fluxes are directed into the mangrove forest, indicating an accretionary environment consistent with satellite observations. Here, contributions from the riverine and bed-sourced sediments are similar. For small to medium discharge scenarios (up to ∼ 280 m3 s-1, flow speeds ∼ 0.6 m s-1), mass loads increase with river discharge. However, in the case of large discharge events, the high momentum in the near-field region allows the river plume to effectively transport sediment through the full width of forested region and out of the forest front. In the mid- and far-field regions of the plume, tidal influences also play a stronger role. Suspended sediment is primarily composed of bed-sourced material and transported out of the forest. Weaker winds are found to affect the far- and mid-field regions of the river plume. Stronger winds are able to reshape the entire plume structure, also including the near-field, such that sediment deposition is enhanced when winds are directed towards the forest.

text: The influence of river plume discharge and winds on sediment transport into a coastal mangrove environment We investigate how the physical forcing factors of river discharge and winds affect sediment delivery to, and retention within, mangrove-lined coastal regions. We use an idealized numerical model, broadly similar to the Firth of Thames deltaic system in New Zealand, to isolate and explore the underlying processes without some of the complexities of the real system. Total sediment transport and the relative contributions of riverine and bed-sourced sediment into the forest are assessed using a transect along the edge of the forest region. The model results demonstrate that both river discharge and winds alter the distribution of sediment transport, and that the spatial patterns relate to different regions of the river plume. At the river mouth (the near-field region), irrespective of the discharge employed, sediment fluxes are directed into the mangrove forest, indicating an accretionary environment consistent with satellite observations. Here, contributions from the riverine and bed-sourced sediments are similar. For small to medium discharge scenarios (up to ∼ 280 m3 s-1, flow speeds ∼ 0.6 m s-1), mass loads increase with river discharge. However, in the case of large discharge events, the high momentum in the near-field region allows the river plume to effectively transport sediment through the full width of forested region and out of the forest front. In the mid- and far-field regions of the plume, tidal influences also play a stronger role. Suspended sediment is primarily composed of bed-sourced material and transported out of the forest. Weaker winds are found to affect the far- and mid-field regions of the river plume. Stronger winds are able to reshape the entire plume structure, also including the near-field, such that sediment deposition is enhanced when winds are directed towards the forest.

year: 2024-06-07

title: Monitoring brown trout (Salmo trutta) eradication in a wildlife sanctuary using environmental DNA

authors: Banks, Jonathan C.

subjects: brown trout

abstract: Restoration of habitats often necessitates the eradication of exotic animals from a specified area. One of the many challenges associated with the removal of introduced animals is determining the distribution and continued presence of individuals in order to efficiently target control operations and minimise any adverse effects associated with removal. We examined the feasibility of using environmental DNA (eDNA) from water samples, relative to more traditional electric fishing, netting and spotlight surveys (i.e., visual observations of the small streams at night), to determine the presence of brown trout. Samples were taken from within the Zealandia Sanctuary near Wellington, New Zealand, before and after treatment with the piscicide rotenone. Using filtration of water samples, we successfully extracted brown trout DNA from water both before and after rotenone treatment. In most cases, DNA presence corresponded to results obtained through netting and spotlight surveys, and in one instance detected the continued presence of trout in a treated stream (which was subsequently confirmed). We conclude that the use of environmental DNA to detect the presence of exotic fish can be a useful tool to assist in the assessment and restoration of aquatic habitats.

text: Monitoring brown trout (Salmo trutta) eradication in a wildlife sanctuary using environmental DNA Restoration of habitats often necessitates the eradication of exotic animals from a specified area. One of the many challenges associated with the removal of introduced animals is determining the distribution and continued presence of individuals in order to efficiently target control operations and minimise any adverse effects associated with removal. We examined the feasibility of using environmental DNA (eDNA) from water samples, relative to more traditional electric fishing, netting and spotlight surveys (i.e., visual observations of the small streams at night), to determine the presence of brown trout. Samples were taken from within the Zealandia Sanctuary near Wellington, New Zealand, before and after treatment with the piscicide rotenone. Using filtration of water samples, we successfully extracted brown trout DNA from water both before and after rotenone treatment. In most cases, DNA presence corresponded to results obtained through netting and spotlight surveys, and in one instance detected the continued presence of trout in a treated stream (which was subsequently confirmed). We conclude that the use of environmental DNA to detect the presence of exotic fish can be a useful tool to assist in the assessment and restoration of aquatic habitats.

year: 2016

title: Shifting tectonic plates of key discourses in New Zealand early childhood education policy (1989-2017):  A critical discourse analysis at the dawn of change

authors: Westbrook, Fiona

subjects: New Zealand

abstract: This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
The findings of this thesis imply socialism, te Ao Māori and neoliberalism are constantly competing with one another in the analysed policies that construct New Zealand ECE discourses and, as a consequence, influence practice. This plurality has the potential to hinder one discourse from gaining domination over the others. Their joint consumption's and conflicts appear to periodically lessen and strengthen neoliberalism’s power/knowledges across eras, administrations, policies and paragraphs, as exemplified in the updated curriculum. These findings imply that the ‘drivers’ of power are pivotal, hindering and strengthening these discourses which are both complementary and competing. Additionally, the thesis establishes implications regarding the rich complexities of discourses, which can conceal themselves in other discourses, calling for deeper critical reflection if some power/knowledges are to be reduced.

text: Shifting tectonic plates of key discourses in New Zealand early childhood education policy (1989-2017):  A critical discourse analysis at the dawn of change This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
This thesis analysed the presence of neoliberalism, socialism and te Ao Māori in fundamental policy documents that frame New Zealand early childhood practice. It did so to critically engage with, and thus make sense of, neoliberalism’s application and potential growth in New Zealand early childhood policies from 1989 to 2017. The research additionally focused on the interplay of socialist and te Ao Māori discourses in these texts, in conjunction with neoliberalism. It employed a poststructuralist conceptual framework that utilised Kristeva’s intertextuality and Foucault’s discourse, governmentality, and power/knowledge. The philosophical framework facilitated an appreciation of the early childhood education (ECE) sector and government discourses, via policies that exhibited discursive power, truths, and knowledges. This thesis’ approach was employed through a critical discourse analysis, incorporating Kristeva’s intertextuality, Fairclough’s manifest intertextuality and interdiscursivity, as well as a keyword search. This form of document analysis was selected because it enabled me as the researcher to gain a deeper more developed understanding of the policy texts, eliciting meaning and recognition of the discourses often naturalised within them. 
 
Contrary to the dominant claims in ECE literature concerning contemporary discourse, the analysis did not discover the neoliberal discourse’s predominance within the selected policies and documents, as was expected. The neoliberal discourse did exist within government endorsed texts, such as the foreword of Te Whāriki (Ministry of Education, 2017b) and Four Year Plan 2016-2020 (Ministry of Education, 2016). However, when the texts came closest to the sector, such as Te Whāraki (Ministry of Education, 1996; 2017b) and the Licensing Criteria Early Childhood Education and Care (Ministry of Education, 2008), the discourses of socialism, te Ao Māori and neoliberalism, nullified, transformed and modified one another. These findings were exemplified in the updated Te Whāraki (Ministry of Education, 2017b), that limited the neoliberal use of individualism from the original, while also upgrading children’s future potential. ‘Future’ within this text, however, was constructed through a modification of te Ao Māori by absorbing and embodying it in incomplete ways.  
 
The findings of this thesis imply socialism, te Ao Māori and neoliberalism are constantly competing with one another in the analysed policies that construct New Zealand ECE discourses and, as a consequence, influence practice. This plurality has the potential to hinder one discourse from gaining domination over the others. Their joint consumption's and conflicts appear to periodically lessen and strengthen neoliberalism’s power/knowledges across eras, administrations, policies and paragraphs, as exemplified in the updated curriculum. These findings imply that the ‘drivers’ of power are pivotal, hindering and strengthening these discourses which are both complementary and competing. Additionally, the thesis establishes implications regarding the rich complexities of discourses, which can conceal themselves in other discourses, calling for deeper critical reflection if some power/knowledges are to be reduced.

year: 2018