title: Detecting low densities of koi carp and other pest fish species in lakes using environmental DNA

authors: Reiser, Ashton

subjects: edna

abstract: Environmental DNA (eDNA) is a quick, effective and sensitive biomonitoring tool that can be used to detect invasive species at low densities in aquatic habitats. The aim of my study was to develop a standard operating protocol (SOP) for the detection of invasive fish in New Zealand’s lowland lakes, specifically koi carp (Cyprinus rubrofuscus). Four separate eDNA surveys between October 2022 and April 2024 sampled 18 lakes in total across the Auckland and Waikato Regions in the North Island of New Zealand. I evaluated different aspects of eDNA sampling including sample collection methods, filter sizes, seasonality, laboratory analysis methods, along with the optimal number of samples and spatial locations to filter water from. My study found that eDNA was a simple, reliable, and effective tool that can be easily used to detect koi and other pest species at low densities across a wide variety of lakes. The efficacy of eDNA sampling was proven during a real-world koi incursion at Lake Waiwhakareke, where I successfully detected koi for the first time in this lake at very low densities using eDNA. Overall, I found that a coarser (5 μm) filter size outperformed the finer (1.2 μm) filter in every comparison and that the qPCR laboratory analysis method was slightly superior to the metabarcoding method, although it has the disadvantage of only being able to detect a single species. My study showed that the multisite composite sample collection method performed marginally better than the single collection overall, across 13 lakes in the Auckland Region. Targeting the littoral margins of the lakes was found to be significantly better in terms of metabarcoding read counts and species detections than sampling the pelagic/mid-lake regions at both Lake Puketirini and Lake Waiwhakareke. In the spatio-temporal study in the Waikato, I found that there was a higher degree of variation between the two seasons sampled (Spring and Autumn) than there was between the three lakes. The spring season performed best in terms of fish detections and metabarcoding read counts. In terms of the sampling number and density, I found that eight samples per kilometre of lake perimeter was found to be optimal to detect koi carp at very low densities at Lake Waiwhakareke and Lake Puketirini. However, further research is needed to better understand the uncertainties involved with eDNA sampling, including the amount of sampling required to provide high levels of confidence in the results. Using negative and positive controls at the time of sampling and during laboratories analyses, in addition to species distribution modelling may help ascertain the sensitivities of eDNA detection with a greater level of certainty.

text: Detecting low densities of koi carp and other pest fish species in lakes using environmental DNA Environmental DNA (eDNA) is a quick, effective and sensitive biomonitoring tool that can be used to detect invasive species at low densities in aquatic habitats. The aim of my study was to develop a standard operating protocol (SOP) for the detection of invasive fish in New Zealand’s lowland lakes, specifically koi carp (Cyprinus rubrofuscus). Four separate eDNA surveys between October 2022 and April 2024 sampled 18 lakes in total across the Auckland and Waikato Regions in the North Island of New Zealand. I evaluated different aspects of eDNA sampling including sample collection methods, filter sizes, seasonality, laboratory analysis methods, along with the optimal number of samples and spatial locations to filter water from. My study found that eDNA was a simple, reliable, and effective tool that can be easily used to detect koi and other pest species at low densities across a wide variety of lakes. The efficacy of eDNA sampling was proven during a real-world koi incursion at Lake Waiwhakareke, where I successfully detected koi for the first time in this lake at very low densities using eDNA. Overall, I found that a coarser (5 μm) filter size outperformed the finer (1.2 μm) filter in every comparison and that the qPCR laboratory analysis method was slightly superior to the metabarcoding method, although it has the disadvantage of only being able to detect a single species. My study showed that the multisite composite sample collection method performed marginally better than the single collection overall, across 13 lakes in the Auckland Region. Targeting the littoral margins of the lakes was found to be significantly better in terms of metabarcoding read counts and species detections than sampling the pelagic/mid-lake regions at both Lake Puketirini and Lake Waiwhakareke. In the spatio-temporal study in the Waikato, I found that there was a higher degree of variation between the two seasons sampled (Spring and Autumn) than there was between the three lakes. The spring season performed best in terms of fish detections and metabarcoding read counts. In terms of the sampling number and density, I found that eight samples per kilometre of lake perimeter was found to be optimal to detect koi carp at very low densities at Lake Waiwhakareke and Lake Puketirini. However, further research is needed to better understand the uncertainties involved with eDNA sampling, including the amount of sampling required to provide high levels of confidence in the results. Using negative and positive controls at the time of sampling and during laboratories analyses, in addition to species distribution modelling may help ascertain the sensitivities of eDNA detection with a greater level of certainty.

year: 2025-07-08

title: Transformations: Anthropology, Art and the Quilt

authors: Wanigasekera, Gwenda Dorothy

subjects: Anthropology

abstract: Drawing on both anthropological and quilt literature, this thesis shows the many different ways that made objects are thought about by different groups of people.  Awareness of these differences permits a new perspective of 'Western' art and object making.  This awareness allows a space in which to consider the importance of the process of making.

Quiltmaking provides an interesting case study.  This thesis therefore describes the field of quiltmaking activity that exists in New Zealand at the present time.  This genre, as it is practised today, had its beginnings in the revival that began in this country during the 1970's.  This study will show that the main impetus of this revival did not draw on known traditions in New Zealand, but rather on a largely imported tradition that had developed in the United States of America.

Ideas about the status of quilts as art objects, comes from a mixture of influences.  The tradition of quiltmaking in the United States was already a strong one and had been through a number of revivals.  Aspects of this traditional culture influenced quiltmakers in New Zealand. Simultaneously, there was an equally strong sense of the quilt as an art object in New Zealand.  However, art entrepreneurs in the United States certainly were part of the transformation of the quilt into an art object in that country.  Their strategies of discourse and display drew on contemporary artworld ideologies and ultimately this valuation affected which quilts could be seen as 'art' in New Zealand.

Through the use of participant observation, interviews and a questionnaire, the content of this study will show the many different ways that New Zealand quiltmakers work, their aims and goals for the quilts they make, and the ways these quilts are perceived by other quilters and the wider public.  Some areas that have resulted in conflict and misunderstandings are discussed. As in any such group, conflicts and misunderstandings arise from the existence of different ways of valuing aspects of cultural activities.

NB Unlike the hard copy of this thesis the colour plates in this electronic version are placed together between the chapters and the appendices.

text: Transformations: Anthropology, Art and the Quilt Drawing on both anthropological and quilt literature, this thesis shows the many different ways that made objects are thought about by different groups of people.  Awareness of these differences permits a new perspective of 'Western' art and object making.  This awareness allows a space in which to consider the importance of the process of making.

Quiltmaking provides an interesting case study.  This thesis therefore describes the field of quiltmaking activity that exists in New Zealand at the present time.  This genre, as it is practised today, had its beginnings in the revival that began in this country during the 1970's.  This study will show that the main impetus of this revival did not draw on known traditions in New Zealand, but rather on a largely imported tradition that had developed in the United States of America.

Ideas about the status of quilts as art objects, comes from a mixture of influences.  The tradition of quiltmaking in the United States was already a strong one and had been through a number of revivals.  Aspects of this traditional culture influenced quiltmakers in New Zealand. Simultaneously, there was an equally strong sense of the quilt as an art object in New Zealand.  However, art entrepreneurs in the United States certainly were part of the transformation of the quilt into an art object in that country.  Their strategies of discourse and display drew on contemporary artworld ideologies and ultimately this valuation affected which quilts could be seen as 'art' in New Zealand.

Through the use of participant observation, interviews and a questionnaire, the content of this study will show the many different ways that New Zealand quiltmakers work, their aims and goals for the quilts they make, and the ways these quilts are perceived by other quilters and the wider public.  Some areas that have resulted in conflict and misunderstandings are discussed. As in any such group, conflicts and misunderstandings arise from the existence of different ways of valuing aspects of cultural activities.

NB Unlike the hard copy of this thesis the colour plates in this electronic version are placed together between the chapters and the appendices.

year: 2006

title: Māori and indigenous views on R and R: Resistance and Resilience

authors: Penehira, Mera

subjects: resilience

abstract: This article explores the development of Mäori and Indigenous frameworks of resilience, considering the impact of engaging with largely State- led notions of resilience on Mäori development. We highlight the closely linked notion of resistance, asserting the necessity of a fi rm political analysis from Indigenous researchers engaged in this discourse. One of the Indigenous criticisms of resilience theories is that by defi nition they assume an acceptance of responsibility for our position as disadvantaged individuals. That is, by examining and developing theories and models of resilience we buy into the idea that this is the way it is and we need simply to get better at bouncing back and being resilient. Resistance, however, represents an approach of collective fi ght- back, exposing the inequitable distribution of power, and actively opposing negative social, political and economic infl uences. This article represents a Mäori Indigenous political response to the resilience discourse.

text: Māori and indigenous views on R and R: Resistance and Resilience This article explores the development of Mäori and Indigenous frameworks of resilience, considering the impact of engaging with largely State- led notions of resilience on Mäori development. We highlight the closely linked notion of resistance, asserting the necessity of a fi rm political analysis from Indigenous researchers engaged in this discourse. One of the Indigenous criticisms of resilience theories is that by defi nition they assume an acceptance of responsibility for our position as disadvantaged individuals. That is, by examining and developing theories and models of resilience we buy into the idea that this is the way it is and we need simply to get better at bouncing back and being resilient. Resistance, however, represents an approach of collective fi ght- back, exposing the inequitable distribution of power, and actively opposing negative social, political and economic infl uences. This article represents a Mäori Indigenous political response to the resilience discourse.

year: 2014