title: The Continental Shelf as a Site for Dredged Material Disposal, Northeast New Zealand

authors: Flaim, Bryna K.

subjects: dredged material

abstract: Disposal of dredged material has been an on-going problem in the Auckland Coastal Marine Area (CMA) since the early 1980s in New Zealand.  Many disposal grounds have been established and used, but public concern over adverse effects resulted in their ultimate closure.  Presently, dredged material is disposed off-shore at a site simultaneously accessed by the Royal New Zealand Navy for disposal of WWII munitions recovered from coastal areas.  As early as the mid-1990s, parliamentary focus groups established the need for a more suitable disposal option for dredged material.  Establishment of a disposal site north of Cuvier Island in waters deeper than 100 m was one of the key recommendations presented by these groups.  The need for a new site was compounded after the establishment of the Hauraki Gulf Marine Park in 2000.  Taking up the majority of the Auckland CMA this culturally significant Park makes the consent for open water disposal a complex process.

A site east of Great Barrier Island in 140 m of water has been identified as a potential suitable site for disposal of dredged material.  The main goal of the present study is to determine the suitability of this site and provide the necessary information required by enforcing authorities for permit submission. 

Investigations to determine the suitability of the site were undertaken in several ways.  An extensive literature review of previous studies was carried out to gain insight into the physical and biological characteristics of the northeast coast and shelf.  The main hydrodynamic features of the region and the observed behaviours were determined.  Attentions were then directed at determining the more specific site characteristics.  Analytical calculations were undertaken using known site parameters to estimate the potential for transport of sediment away from the site after disposal.  Through analysis of known wave and current measurements it was estimated that only rarely would sediment be entrained off the seafloor.  Samples were then collected from the site in November 2007, which were used for sediment textural analysis and benthic identification.  It was determined that the main textural component of the site sediments is muddy/sand.  Diversity of benthic species is relatively high, but abundance is low.  Polychaetes were the most diverse and abundant taxon identified at sample locations across the site.  Next, the 3DD model was used to numerically simulate 2-dimensional tidal currents.  Depth-averaged spring tidal currents at the site were predicted to be less than 0.2 ms-1.  The derived bottom velocity for such a current is 0.08 ms-1, which is much less than the velocity required for initiation of sediment movement in this case.  The numerical simulation also showed that residual spring tidal flow is directed to the southeast.  Finally, an assessment of potential impacts was done by reviewing previous studies of ecological impacts caused by disposal of dredged material.  Based on the preliminary studies summarised above, the review of potential impacts indicates that there will only be minimal effects at and surrounding the proposed site.  The result of this study is an encouraging step toward establishment of a new disposal option, but further research is required to confidently declare that the site is suitable for disposal operations.

text: The Continental Shelf as a Site for Dredged Material Disposal, Northeast New Zealand Disposal of dredged material has been an on-going problem in the Auckland Coastal Marine Area (CMA) since the early 1980s in New Zealand.  Many disposal grounds have been established and used, but public concern over adverse effects resulted in their ultimate closure.  Presently, dredged material is disposed off-shore at a site simultaneously accessed by the Royal New Zealand Navy for disposal of WWII munitions recovered from coastal areas.  As early as the mid-1990s, parliamentary focus groups established the need for a more suitable disposal option for dredged material.  Establishment of a disposal site north of Cuvier Island in waters deeper than 100 m was one of the key recommendations presented by these groups.  The need for a new site was compounded after the establishment of the Hauraki Gulf Marine Park in 2000.  Taking up the majority of the Auckland CMA this culturally significant Park makes the consent for open water disposal a complex process.

A site east of Great Barrier Island in 140 m of water has been identified as a potential suitable site for disposal of dredged material.  The main goal of the present study is to determine the suitability of this site and provide the necessary information required by enforcing authorities for permit submission. 

Investigations to determine the suitability of the site were undertaken in several ways.  An extensive literature review of previous studies was carried out to gain insight into the physical and biological characteristics of the northeast coast and shelf.  The main hydrodynamic features of the region and the observed behaviours were determined.  Attentions were then directed at determining the more specific site characteristics.  Analytical calculations were undertaken using known site parameters to estimate the potential for transport of sediment away from the site after disposal.  Through analysis of known wave and current measurements it was estimated that only rarely would sediment be entrained off the seafloor.  Samples were then collected from the site in November 2007, which were used for sediment textural analysis and benthic identification.  It was determined that the main textural component of the site sediments is muddy/sand.  Diversity of benthic species is relatively high, but abundance is low.  Polychaetes were the most diverse and abundant taxon identified at sample locations across the site.  Next, the 3DD model was used to numerically simulate 2-dimensional tidal currents.  Depth-averaged spring tidal currents at the site were predicted to be less than 0.2 ms-1.  The derived bottom velocity for such a current is 0.08 ms-1, which is much less than the velocity required for initiation of sediment movement in this case.  The numerical simulation also showed that residual spring tidal flow is directed to the southeast.  Finally, an assessment of potential impacts was done by reviewing previous studies of ecological impacts caused by disposal of dredged material.  Based on the preliminary studies summarised above, the review of potential impacts indicates that there will only be minimal effects at and surrounding the proposed site.  The result of this study is an encouraging step toward establishment of a new disposal option, but further research is required to confidently declare that the site is suitable for disposal operations.

year: 2008

title: Dwelling in the city: A qualitative exploration of the human-nature relationship in three types of urban greenspace

authors: Elliot Noe, Elizabeth Emma

subjects: Connection to nature

abstract: The combination of increasing numbers of people in cities, coupled with decreasing levels of biodiversity, is hypothesised to result in the extinction of experience, or the continued disintegration of the human relationship with the natural world. We use the concepts of sense of place and dwelling to investigate the human relationship with nature in cities by considering the emotional connections between people and places. We conducted ‘go-along’ interviews with 21 residents of Hamilton, New Zealand, to explore the significance of neighbourhood parks and home gardens in the lives of urban residents. Our study highlights the importance of greenspaces in cities to the physical, mental and social health of local residents. Bush parks provided the best opportunities for respondents to observe nature and thereby escape the stress of city life. Participants wanted a variety of parks which would meet the range of their community’s needs and provide habitat for wildlife. Proximity and frequent use of parks resulted in a sense of ownership and responsibility which led to concrete action, such as participation in ecological restoration of valued greenspaces. Providing high quality natural greenspaces within walking distance of residents’ homes disrupts the extinction of experience by fostering positive personal experiences of nature, crucial for the health and wellbeing of people and for native biodiversity.

text: Dwelling in the city: A qualitative exploration of the human-nature relationship in three types of urban greenspace The combination of increasing numbers of people in cities, coupled with decreasing levels of biodiversity, is hypothesised to result in the extinction of experience, or the continued disintegration of the human relationship with the natural world. We use the concepts of sense of place and dwelling to investigate the human relationship with nature in cities by considering the emotional connections between people and places. We conducted ‘go-along’ interviews with 21 residents of Hamilton, New Zealand, to explore the significance of neighbourhood parks and home gardens in the lives of urban residents. Our study highlights the importance of greenspaces in cities to the physical, mental and social health of local residents. Bush parks provided the best opportunities for respondents to observe nature and thereby escape the stress of city life. Participants wanted a variety of parks which would meet the range of their community’s needs and provide habitat for wildlife. Proximity and frequent use of parks resulted in a sense of ownership and responsibility which led to concrete action, such as participation in ecological restoration of valued greenspaces. Providing high quality natural greenspaces within walking distance of residents’ homes disrupts the extinction of experience by fostering positive personal experiences of nature, crucial for the health and wellbeing of people and for native biodiversity.

year: 2023-02-01

title: Land/seascapes of exclusion: social order on the coastal margins

authors: Ryks, John

abstract: The hegemonic discourse of coastal planning and development has an impact on the social ordering of Aotearoa/New Zealand’s coastal communities in a number of ways. One way in which social order is controlled and maintained is through the (ab)use of boundaries. Boundaries constructed and maintained under the authority of government and/or funded by development dictate where people may or may not live. In many cases these boundaries are used as instruments of exclusion. Boundaries constructed by hegemonic groups exclude those who define the coast according to other criteria. The hegemonic deployment of boundaries and the domination of coastal people and place generally is explored through an analysis of discourse. This analysis is structured according to differences in social order, coded as places of Otherness (heterotopia), Euclidean coasts, and places in transition reflecting images of both the former and the latter.
Drawing on a number of coastal communities, including the Northland community of Otia (otherwise known as the Seaweed Pickers), Taylor’s Mistake, Whitianga and the wealth enclave of Pauanui, it is shown that the land/seascape of coastal Aotearoa/New Zealand is gradually being disciplined through the design of coasts that are accommodating of a particular patronage. These ‘exclusive’ coasts appear in stark contrast to those places where an alternative social ordering takes place. Here, in the absence of a Euclidean spatiality, uncertainty and liminality feature in the social construction of the coast. Residents of these places mark out and define the coast in a way that is quite different from the accepted norm, a fact that determines a particular ‘cartographic anxiety’ on the part of the dominant. This anxiety is instrumental in the construction of Otherness and the (re)production of exclusion.

text: Land/seascapes of exclusion: social order on the coastal margins The hegemonic discourse of coastal planning and development has an impact on the social ordering of Aotearoa/New Zealand’s coastal communities in a number of ways. One way in which social order is controlled and maintained is through the (ab)use of boundaries. Boundaries constructed and maintained under the authority of government and/or funded by development dictate where people may or may not live. In many cases these boundaries are used as instruments of exclusion. Boundaries constructed by hegemonic groups exclude those who define the coast according to other criteria. The hegemonic deployment of boundaries and the domination of coastal people and place generally is explored through an analysis of discourse. This analysis is structured according to differences in social order, coded as places of Otherness (heterotopia), Euclidean coasts, and places in transition reflecting images of both the former and the latter.
Drawing on a number of coastal communities, including the Northland community of Otia (otherwise known as the Seaweed Pickers), Taylor’s Mistake, Whitianga and the wealth enclave of Pauanui, it is shown that the land/seascape of coastal Aotearoa/New Zealand is gradually being disciplined through the design of coasts that are accommodating of a particular patronage. These ‘exclusive’ coasts appear in stark contrast to those places where an alternative social ordering takes place. Here, in the absence of a Euclidean spatiality, uncertainty and liminality feature in the social construction of the coast. Residents of these places mark out and define the coast in a way that is quite different from the accepted norm, a fact that determines a particular ‘cartographic anxiety’ on the part of the dominant. This anxiety is instrumental in the construction of Otherness and the (re)production of exclusion.

year: 2002