title: A bioenergetic assessment of the influence of stocking practices on rainbow trout (Oncorhynchus mykiss) growth and consumption in a New Zealand lake

authors: Blair, Jennifer Marie

subjects: density dependence

abstract: To investigate the carrying capacity and factors affecting growth of rainbow trout in Lake Rotoiti, we employed a bioenergetics model to assess the influence of stocking rates, timing of releases and prey abundance on growth and prey consumption. We hypothesised that stocking rates and prey abundance would affect growth and prey consumption by influencing per-capita prey availability, and that the environmental conditions encountered by fish at the time of stocking would affect growth and consumption.
Prey consumption of stocked rainbow trout was calculated with the Wisconsin bioenergetics model. We calculated growth trajectories of released trout based on data from stocked trout that were released in spring and autumn from 1993 to 2009 and then re-captured by anglers. Diet, prey energy density, body mass lost during spawning and lake temperature were measured locally.
Stocking timing had no effect on return rates to anglers or length or weight of caught fish. Although trout released in autumn were smaller than those released in spring, autumn-released trout grew at a faster rate and had similar lengths and weights to spring cohorts after 2 years of growth in the lake. Modelled consumption parameters were negatively correlated with trout population size, suggesting that stocking rates (347–809 fish ha−1 year−1) caused density-dependent effects on growth. Although common smelt (Retropinna retropinna) accounted for 85% of total prey consumption, no significant relationship was found between prey consumption by individual trout and adult smelt abundance, possibly because trout are targeting smaller smelt that our abundance estimate did not account for.
Releasing trout in autumn appears to be advantageous for growth, possibly because (i) temperature is more suitable for growth in autumn–winter than in spring–summer and (ii) prey for small trout is abundant in autumn. Mild winter conditions appear to enhance overwinter survival and growth of rainbow trout in warm-temperate lakes compared to higher latitudes. This implies that moderately productive warm-temperate lake ecosystems are highly suitable for trout growth in winter, but less so in summer, when lake stratification and high nutrient levels may create conditions suitable for algal blooms and hypolimnetic deoxygenation. High growth rates of trout in warm-temperate lakes can therefore be supported by timing releases to coincide with favourable winter conditions.

text: A bioenergetic assessment of the influence of stocking practices on rainbow trout (Oncorhynchus mykiss) growth and consumption in a New Zealand lake To investigate the carrying capacity and factors affecting growth of rainbow trout in Lake Rotoiti, we employed a bioenergetics model to assess the influence of stocking rates, timing of releases and prey abundance on growth and prey consumption. We hypothesised that stocking rates and prey abundance would affect growth and prey consumption by influencing per-capita prey availability, and that the environmental conditions encountered by fish at the time of stocking would affect growth and consumption.
Prey consumption of stocked rainbow trout was calculated with the Wisconsin bioenergetics model. We calculated growth trajectories of released trout based on data from stocked trout that were released in spring and autumn from 1993 to 2009 and then re-captured by anglers. Diet, prey energy density, body mass lost during spawning and lake temperature were measured locally.
Stocking timing had no effect on return rates to anglers or length or weight of caught fish. Although trout released in autumn were smaller than those released in spring, autumn-released trout grew at a faster rate and had similar lengths and weights to spring cohorts after 2 years of growth in the lake. Modelled consumption parameters were negatively correlated with trout population size, suggesting that stocking rates (347–809 fish ha−1 year−1) caused density-dependent effects on growth. Although common smelt (Retropinna retropinna) accounted for 85% of total prey consumption, no significant relationship was found between prey consumption by individual trout and adult smelt abundance, possibly because trout are targeting smaller smelt that our abundance estimate did not account for.
Releasing trout in autumn appears to be advantageous for growth, possibly because (i) temperature is more suitable for growth in autumn–winter than in spring–summer and (ii) prey for small trout is abundant in autumn. Mild winter conditions appear to enhance overwinter survival and growth of rainbow trout in warm-temperate lakes compared to higher latitudes. This implies that moderately productive warm-temperate lake ecosystems are highly suitable for trout growth in winter, but less so in summer, when lake stratification and high nutrient levels may create conditions suitable for algal blooms and hypolimnetic deoxygenation. High growth rates of trout in warm-temperate lakes can therefore be supported by timing releases to coincide with favourable winter conditions.

year: 2013

title: Plots, plants and paradoxes: contemporary domestic gardens in Aotearoa/New Zealand

authors: Longhurst, Robyn

subjects: domestic gardens

abstract: Currently, gardens, gardening and horticulture—plots and plants—are receiving increasing attention from geographers and others interested in spatial disciplines because they provide a useful lens for understanding the complex politics surrounding social and cultural life. In this paper I aim to add to this literature by examining contemporary domestic gardens as paradoxical spaces. The paper begins by outlining some of the reasons for choosing to examine contemporary domestic gardens. Following this is a brief review of a range of geographical literature on gardens, gardening and horticulture. The paper then presents data collected on domestic gardens and gardening practices in Hamilton and Auckland, Aotearoa/New Zealand to illustrate that domestic gardens are paradoxical spaces where the binaries nature and culture, private and public, individuality and sociality, leisure and work, and colonial and postcolonial are destabilized. The paper concludes that although domestic gardens are paradoxical spaces, this does not necessarily mean that they pose a threat or danger because of their ambiguity, or that they are sites of radical politics. Rather domestic gardens are spaces where it is possible to reinforce hegemonic geographies and/or create alternative ones.
Les jardins, le jardinage et l'horticulture—les parcelles et les plantes—bénéficient présentement d'une attention accrue de la part de géographes et de ceux qui s'intéressent aux disciplines spatiales, car celles-ci fournissent une lentille utile pour saisir les questions politiques complexes entourant la vie sociale et culturelle. Par cet article, je souhaite apporter une contribution à la littérature de ce domaine en considérant les jardins domestiques contemporains comme des espaces paradoxaux. D'entrée de jeu, cet article présente brièvement les raisons pour lesquelles les jardins domestiques contemporains ont fait l'objet d'une étude et passe en revue la littérature géographique sur les jardins, le jardinage et l'horticulture. Par la suite, cet article présente les données recueillies sur les jardins privés et les pratiques de jardinage à Hamilton et à Auckland, en Aotearoa/Nouvelle Zélande dans le but de montrer que les jardins domestiques sont des espaces paradoxaux dans lesquels les couples nature et culture, privé et public, individualité et socialité, loisir et travail, et colonial et postcolonial sont ébranlés. En terminant, bien que les jardins privés soient des espaces paradoxaux, cela ne signifie pas pour autant qu'ils constituent une menace ou un danger en raison de leur ambiguïté, ou qu'ils représentent des lieux de politiques extrémistes. Les jardins domestiques, en fait, sont des espaces o[ugrave] il est envisageable de consolider des géographies hégémoniques et/ou de d'en concevoir d'autres.
Actualmente los jardines, jardinería y horticultura—parcelas y plantas—reciben cada vez mas atención de los geógrafos y otros interesados en las disciplinas espaciales, ya que ofrecen una manera útil de entender la compleja política de la vida social y cultural. En este papel, pretendo ampliar esta literatura por medio de un examen de los jardines domésticos como espacios paradójicos. El papel empieza con una breve descripción de algunos de los motivos por haber elegido estudiar los jardines domésticos contemporáneos. Luego hay un resumen de una variedad de literatura geográfica sobre jardines, jardinería y horticultura. Después el papel presenta datos sobre jardines domésticos y costumbres de jardinería en Hamilton y Aukland, Aotearoa/Nuevo Zelanda para ilustrar que los jardines domésticos son espacios paradójicos donde se ven desestablecidos los binarios naturaleza/cultura, privado/publico, individualidad/socialidad, ocio/trabajo y colonial/poscolonial. El papel concluye por decir que el hecho de que son espacios paradójicos no quiere decir que los jardines domésticos representen una amenaza o peligro por causa de su ambigüedad o que sean sitios de política radical. Más bien los jardines domésticos son espacios donde es posible reforzar geografías hegemónicas y/o crear otras alternativas.

text: Plots, plants and paradoxes: contemporary domestic gardens in Aotearoa/New Zealand Currently, gardens, gardening and horticulture—plots and plants—are receiving increasing attention from geographers and others interested in spatial disciplines because they provide a useful lens for understanding the complex politics surrounding social and cultural life. In this paper I aim to add to this literature by examining contemporary domestic gardens as paradoxical spaces. The paper begins by outlining some of the reasons for choosing to examine contemporary domestic gardens. Following this is a brief review of a range of geographical literature on gardens, gardening and horticulture. The paper then presents data collected on domestic gardens and gardening practices in Hamilton and Auckland, Aotearoa/New Zealand to illustrate that domestic gardens are paradoxical spaces where the binaries nature and culture, private and public, individuality and sociality, leisure and work, and colonial and postcolonial are destabilized. The paper concludes that although domestic gardens are paradoxical spaces, this does not necessarily mean that they pose a threat or danger because of their ambiguity, or that they are sites of radical politics. Rather domestic gardens are spaces where it is possible to reinforce hegemonic geographies and/or create alternative ones.
Les jardins, le jardinage et l'horticulture—les parcelles et les plantes—bénéficient présentement d'une attention accrue de la part de géographes et de ceux qui s'intéressent aux disciplines spatiales, car celles-ci fournissent une lentille utile pour saisir les questions politiques complexes entourant la vie sociale et culturelle. Par cet article, je souhaite apporter une contribution à la littérature de ce domaine en considérant les jardins domestiques contemporains comme des espaces paradoxaux. D'entrée de jeu, cet article présente brièvement les raisons pour lesquelles les jardins domestiques contemporains ont fait l'objet d'une étude et passe en revue la littérature géographique sur les jardins, le jardinage et l'horticulture. Par la suite, cet article présente les données recueillies sur les jardins privés et les pratiques de jardinage à Hamilton et à Auckland, en Aotearoa/Nouvelle Zélande dans le but de montrer que les jardins domestiques sont des espaces paradoxaux dans lesquels les couples nature et culture, privé et public, individualité et socialité, loisir et travail, et colonial et postcolonial sont ébranlés. En terminant, bien que les jardins privés soient des espaces paradoxaux, cela ne signifie pas pour autant qu'ils constituent une menace ou un danger en raison de leur ambiguïté, ou qu'ils représentent des lieux de politiques extrémistes. Les jardins domestiques, en fait, sont des espaces o[ugrave] il est envisageable de consolider des géographies hégémoniques et/ou de d'en concevoir d'autres.
Actualmente los jardines, jardinería y horticultura—parcelas y plantas—reciben cada vez mas atención de los geógrafos y otros interesados en las disciplinas espaciales, ya que ofrecen una manera útil de entender la compleja política de la vida social y cultural. En este papel, pretendo ampliar esta literatura por medio de un examen de los jardines domésticos como espacios paradójicos. El papel empieza con una breve descripción de algunos de los motivos por haber elegido estudiar los jardines domésticos contemporáneos. Luego hay un resumen de una variedad de literatura geográfica sobre jardines, jardinería y horticultura. Después el papel presenta datos sobre jardines domésticos y costumbres de jardinería en Hamilton y Aukland, Aotearoa/Nuevo Zelanda para ilustrar que los jardines domésticos son espacios paradójicos donde se ven desestablecidos los binarios naturaleza/cultura, privado/publico, individualidad/socialidad, ocio/trabajo y colonial/poscolonial. El papel concluye por decir que el hecho de que son espacios paradójicos no quiere decir que los jardines domésticos representen una amenaza o peligro por causa de su ambigüedad o que sean sitios de política radical. Más bien los jardines domésticos son espacios donde es posible reforzar geografías hegemónicas y/o crear otras alternativas.

year: 2006

title: Kūkū te kererū, ketekete te kākā: The role of literature in indigenous methods of naming native and introduced birds to Aotearoa New Zealand

authors: Raharuhi, Te Urukeiha

subjects: indigenous methods of naming

abstract: This thesis describes the role of academic literature in indigenous epistemology with a focus on indigenous methods of naming native and introduced birds to Aotearoa New Zealand. The story of the role of academic literature in mātauranga Māori transmission presented in this thesis, describes a narrative of indigenous people being increasingly excluded from transmission of mātauranga Māori in literature production. Importantly the exclusion of original sources from participation in literature production and revision resulted in a high degree of persistent error in academic literature presenting oral narratives and te reo Māori bird names.

Currently, te reo Māori names of native and introduced birds are represented in English language academic literature, as subject matter or topic of interest predominately within a scientific research paradigm, in the fields of linguistics, ornithology, ethnology or disciplines where these are combined such as ethno-ornithology or folk-taxonomy. Research inquiry conducted in this study is influenced by a potential to explore indigenous methods of naming in terms of what they reveal about our ways of being (ontology) and our ways of knowing (epistemology).

This thesis presents two literature reviews and the findings of seven semi-structured interviews to explore the complexities of the role of academic literature in indigenous epistemology with a focus on indigenous methods of naming native and indigenous birds to Aotearoa New Zealand. Exploring indigenous methods of naming in this way provides an opportunity to tease out the influence of translation, Western scientific paradigms and the medium of academic literature on the transmission of mātauranga Māori as well as identify opportunities and limitations for indigenous epistemology offered through the medium of academic literature.

A comprehensive index of te reo Māori bird names with attention to the variety of linguistic nuances of geographically specific vernacular presented consistently in the context of indigenous methods of naming, potentially provides an accessible and meaningful taxonomic reference document. At the present time such an index has not been published. The findings of the research presented in this thesis support the potential of academic literature to meaningfully contribute to indigenous methods of naming when it records or facilitates direct participation of hapū in indigenous epistemology rather than predetermine or prematurely theorise indigenous methods of naming native and introduced birds to Aotearoa New Zealand. Equally, it presents findings to support potential for academic literature to contribute to mātauranga Māori when it articulates indigenous epistemology as a valuable way of knowing and does not assume to replace memory arts as the primary methods of mātauranga Māori transmission. Furthermore, the application of an indigenous paradigm to the production of literature about indigenous methods of naming as an aspect of mātauranga Māori has the potential to constitute an accurate and authentic body of knowledge.

text: Kūkū te kererū, ketekete te kākā: The role of literature in indigenous methods of naming native and introduced birds to Aotearoa New Zealand This thesis describes the role of academic literature in indigenous epistemology with a focus on indigenous methods of naming native and introduced birds to Aotearoa New Zealand. The story of the role of academic literature in mātauranga Māori transmission presented in this thesis, describes a narrative of indigenous people being increasingly excluded from transmission of mātauranga Māori in literature production. Importantly the exclusion of original sources from participation in literature production and revision resulted in a high degree of persistent error in academic literature presenting oral narratives and te reo Māori bird names.

Currently, te reo Māori names of native and introduced birds are represented in English language academic literature, as subject matter or topic of interest predominately within a scientific research paradigm, in the fields of linguistics, ornithology, ethnology or disciplines where these are combined such as ethno-ornithology or folk-taxonomy. Research inquiry conducted in this study is influenced by a potential to explore indigenous methods of naming in terms of what they reveal about our ways of being (ontology) and our ways of knowing (epistemology).

This thesis presents two literature reviews and the findings of seven semi-structured interviews to explore the complexities of the role of academic literature in indigenous epistemology with a focus on indigenous methods of naming native and indigenous birds to Aotearoa New Zealand. Exploring indigenous methods of naming in this way provides an opportunity to tease out the influence of translation, Western scientific paradigms and the medium of academic literature on the transmission of mātauranga Māori as well as identify opportunities and limitations for indigenous epistemology offered through the medium of academic literature.

A comprehensive index of te reo Māori bird names with attention to the variety of linguistic nuances of geographically specific vernacular presented consistently in the context of indigenous methods of naming, potentially provides an accessible and meaningful taxonomic reference document. At the present time such an index has not been published. The findings of the research presented in this thesis support the potential of academic literature to meaningfully contribute to indigenous methods of naming when it records or facilitates direct participation of hapū in indigenous epistemology rather than predetermine or prematurely theorise indigenous methods of naming native and introduced birds to Aotearoa New Zealand. Equally, it presents findings to support potential for academic literature to contribute to mātauranga Māori when it articulates indigenous epistemology as a valuable way of knowing and does not assume to replace memory arts as the primary methods of mātauranga Māori transmission. Furthermore, the application of an indigenous paradigm to the production of literature about indigenous methods of naming as an aspect of mātauranga Māori has the potential to constitute an accurate and authentic body of knowledge.

year: 2015