title: Environmentally Sustainable Aquaculture: An Eco-Physical Perspective

authors: Longdill, Peter C.

subjects: Bay of Plenty

abstract: The New Zealand aquaculture industry during the late 1990s and early 2000s experienced a significant and sustained period of growth.  Greenshell mussels (Perna canaliculus) are proving to be a popular and valuable cultured species, with large domestic and international markets.  Traditionally, these bivalves have been farmed within enclosed embayments and on relatively small scales (~3 Ha).  The recent expansion of the industry coupled with the near saturation of existing 'traditional' sites and new culture technologies has led the industry toward alternate environments, notably exposed offshore sites.  Initial proposals within the Bay of Plenty have included multiple farms of ~4500 Ha each.  This novel approach to shellfish culture created uncertainty with respect to potential environmental impacts, cumulative effects, and sustainable carrying capacities within these exposed open-coast locations.  In zoning for Aquaculture Management Areas (AMAs), environmental managers must be informed of each of these aspects to ensure the rational and sustainable use of the coastal-marine space.

The overall goal of this study is to determine the potential for environmentally sustainable large-scale offshore mussel culture within the Bay of Plenty marine environment.  The long term sustainability of aquaculture development on an open coast is a function of many influences which can vary in both time and space.  The benthic environments of the Bay of Plenty exhibit great variability in their ability to assimilate waste inputs from suspended mussel culture; a direct function of the variability in sedimentary environments and benthic habitats within the region.  Specifically, silty sediments with low natural organic contents, generally found between 40 and 100 m depths are the most suitable locations for sustainable mussel aquaculture from an environmental impact perspective.  Both observations and model predictions indicate productivity potential within the region to be greatest within neritic zones of the western Bay of Plenty.  Local wind forcing is the predominant mechanism forcing local shelf currents.  Current meter data and numerical modelling tests from this study indicate that local winds explain the majority of water current variability on the shelf, generate the delivery of new nutrients to the shelf through upwelling, and hence create the variability in productivity potential.  Complicating the AMA zoning process for environmental managers, however, are existing uses of, and societal values toward, the coastal-marine environment.  GIS planning tools have been shown to be effective at minimising conflicts and maximising sustainability potential through informed site selection.  Within the Bay of Plenty, these preferential sites are located on the mid-shelf (60-80 m depths) offshore from Pukehina, Matata, and Whakatane.  

This study shows that the simulated cumulative lower trophic-level depletion impacts of two large (~5000 Ha) proposed offshore mussel farms vary seasonally as a result of subtle changes in ecosystem dynamics and mussel feeding patterns.  At proposed stocking densities, largest relative impacts are expected during autumn and winter, when relative phytoplankton biomass is low and growth rates slow.  During spring, while absolute impacts are greater than those during autumn/winter, greater phytoplankton-zooplankton biomass and faster growth rates result in quicker recovery times and reduced 'depletion halo' extents.  Year-long predicted impacts are below those applied as 'acceptable limits of change', both within New Zealand and internationally, indicative of the ecological carrying capacity.

text: Environmentally Sustainable Aquaculture: An Eco-Physical Perspective The New Zealand aquaculture industry during the late 1990s and early 2000s experienced a significant and sustained period of growth.  Greenshell mussels (Perna canaliculus) are proving to be a popular and valuable cultured species, with large domestic and international markets.  Traditionally, these bivalves have been farmed within enclosed embayments and on relatively small scales (~3 Ha).  The recent expansion of the industry coupled with the near saturation of existing 'traditional' sites and new culture technologies has led the industry toward alternate environments, notably exposed offshore sites.  Initial proposals within the Bay of Plenty have included multiple farms of ~4500 Ha each.  This novel approach to shellfish culture created uncertainty with respect to potential environmental impacts, cumulative effects, and sustainable carrying capacities within these exposed open-coast locations.  In zoning for Aquaculture Management Areas (AMAs), environmental managers must be informed of each of these aspects to ensure the rational and sustainable use of the coastal-marine space.

The overall goal of this study is to determine the potential for environmentally sustainable large-scale offshore mussel culture within the Bay of Plenty marine environment.  The long term sustainability of aquaculture development on an open coast is a function of many influences which can vary in both time and space.  The benthic environments of the Bay of Plenty exhibit great variability in their ability to assimilate waste inputs from suspended mussel culture; a direct function of the variability in sedimentary environments and benthic habitats within the region.  Specifically, silty sediments with low natural organic contents, generally found between 40 and 100 m depths are the most suitable locations for sustainable mussel aquaculture from an environmental impact perspective.  Both observations and model predictions indicate productivity potential within the region to be greatest within neritic zones of the western Bay of Plenty.  Local wind forcing is the predominant mechanism forcing local shelf currents.  Current meter data and numerical modelling tests from this study indicate that local winds explain the majority of water current variability on the shelf, generate the delivery of new nutrients to the shelf through upwelling, and hence create the variability in productivity potential.  Complicating the AMA zoning process for environmental managers, however, are existing uses of, and societal values toward, the coastal-marine environment.  GIS planning tools have been shown to be effective at minimising conflicts and maximising sustainability potential through informed site selection.  Within the Bay of Plenty, these preferential sites are located on the mid-shelf (60-80 m depths) offshore from Pukehina, Matata, and Whakatane.  

This study shows that the simulated cumulative lower trophic-level depletion impacts of two large (~5000 Ha) proposed offshore mussel farms vary seasonally as a result of subtle changes in ecosystem dynamics and mussel feeding patterns.  At proposed stocking densities, largest relative impacts are expected during autumn and winter, when relative phytoplankton biomass is low and growth rates slow.  During spring, while absolute impacts are greater than those during autumn/winter, greater phytoplankton-zooplankton biomass and faster growth rates result in quicker recovery times and reduced 'depletion halo' extents.  Year-long predicted impacts are below those applied as 'acceptable limits of change', both within New Zealand and internationally, indicative of the ecological carrying capacity.

year: 2008

title: A map-based place-browser for a PDA

authors: Bainbridge, David

subjects: mobile searching

abstract: This article describes PlaceBrowser, a PDA based application that allows the user of the application to navigate around an area of geographical interest, such as a city, using a zoomable, panable hierarchy of aerial images, in a fashion similar to Google Maps. The novel aspect to the work is that an area of precise interest within the map can be pin-pointed by the user by directly dragging out a rectangular area on the map. This forms the source to a spatial search that returns landmarks that are then used to trigger a Web based query. The results of this query are displayed to the user. The net effect is that, in response to dragging out a rectangular area, web pages that are relevant to this area but have not been explicitly geo-spatially tagged with metadata (longitude,latitude) are shown to the user.

text: A map-based place-browser for a PDA This article describes PlaceBrowser, a PDA based application that allows the user of the application to navigate around an area of geographical interest, such as a city, using a zoomable, panable hierarchy of aerial images, in a fashion similar to Google Maps. The novel aspect to the work is that an area of precise interest within the map can be pin-pointed by the user by directly dragging out a rectangular area on the map. This forms the source to a spatial search that returns landmarks that are then used to trigger a Web based query. The results of this query are displayed to the user. The net effect is that, in response to dragging out a rectangular area, web pages that are relevant to this area but have not been explicitly geo-spatially tagged with metadata (longitude,latitude) are shown to the user.

year: 2007-10-24

title: Ngā whakaaro o ngā ākonga: perspectives and experiences of Māori students in outdoor education in Aotearoa New Zealand

authors: Washbourn, Phil

subjects: Outdoor education

abstract: This study aims to develop an understanding of the perspectives and experiences of Māori students in a secondary school outdoor education programme in Aotearoa New Zealand. Lynch (2012) indicated that “there is a clear need, and wide scope, for research into: cultural elements of outdoor education programmes; cultural effects on participants; culturally appropriate research approaches and programme effects on, and experiences of, people who identify as Māori” (p.49). Outdoor education in Aotearoa New Zealand has been heavily influenced by ‘Eurocentric’ values and practices that contrast with those of Te Ao Māori. In line with a number of calls to re-envision the field, the perspectives and experiences of Māori and the incorporation of Te Ao Māori pedagogies are vital to the reconstruction of an integrated and inclusive Aotearoa New Zealand expression of Outdoor Education for the 21st century.
This study, guided by culturally responsive research methodology, used focus groups to investigate the opinions, thoughts and expectations of Māori students of outdoor education. Thematic analysis was used to analyse the focus group data, and four major themes were identified: the importance of shared experience and relationships to positive experiences of outdoor education; the distinctive practices of outdoor education make learning enjoyable and engaging; the importance to students of making connections with Te Ao Māori through experience, stories of places and history; and the complexity of engaging Māori in participation in outdoor education, including factors such as affordability, the influence of friends and whānau and prioritising educational pathways. A range of practices and approaches from Te Ao Māori are considered and presented, based on the contribution of the student participants, including pedagogical principles from Te Ao Māori such as wānanga, whanaungatanga and tauira. Suggestions for practice include developing connections within the community and experiencing Te Ao Māori learning contexts such as waka ama, noho marae and mahinga kai.

text: Ngā whakaaro o ngā ākonga: perspectives and experiences of Māori students in outdoor education in Aotearoa New Zealand This study aims to develop an understanding of the perspectives and experiences of Māori students in a secondary school outdoor education programme in Aotearoa New Zealand. Lynch (2012) indicated that “there is a clear need, and wide scope, for research into: cultural elements of outdoor education programmes; cultural effects on participants; culturally appropriate research approaches and programme effects on, and experiences of, people who identify as Māori” (p.49). Outdoor education in Aotearoa New Zealand has been heavily influenced by ‘Eurocentric’ values and practices that contrast with those of Te Ao Māori. In line with a number of calls to re-envision the field, the perspectives and experiences of Māori and the incorporation of Te Ao Māori pedagogies are vital to the reconstruction of an integrated and inclusive Aotearoa New Zealand expression of Outdoor Education for the 21st century.
This study, guided by culturally responsive research methodology, used focus groups to investigate the opinions, thoughts and expectations of Māori students of outdoor education. Thematic analysis was used to analyse the focus group data, and four major themes were identified: the importance of shared experience and relationships to positive experiences of outdoor education; the distinctive practices of outdoor education make learning enjoyable and engaging; the importance to students of making connections with Te Ao Māori through experience, stories of places and history; and the complexity of engaging Māori in participation in outdoor education, including factors such as affordability, the influence of friends and whānau and prioritising educational pathways. A range of practices and approaches from Te Ao Māori are considered and presented, based on the contribution of the student participants, including pedagogical principles from Te Ao Māori such as wānanga, whanaungatanga and tauira. Suggestions for practice include developing connections within the community and experiencing Te Ao Māori learning contexts such as waka ama, noho marae and mahinga kai.

year: 2018