title: A cardano blockchain prototype for migrant data security and cultural heritage preservation

authors: Rengasamy Rajamanikkam, Vikneswaran

subjects: Blockchain

abstract: This thesis investigates the challenges faced by migrants in managing and sharing personal data during migration processes, as well as the potential privacy, security, and data sovereignty risks that may arise from poor data management practices or malicious actors. It further examines the difficulties migrants face in preserving their cultural heritage within their host countries.

Migrants are often required to disclose extensive personal and sensitive information to immigration authorities and associated organisations, which raises significant concerns regarding data privacy, data security, and data sovereignty. These issues may result in adverse outcomes, including misuse of data, loss of control over personal information, and the loss of cultural identity. To better understand these challenges, a study was conducted with twenty migrants to explore their experiences with documentation procedures, their awareness of potential privacy risks, and their perspectives on safeguarding cultural heritage information.

Based on insights from existing literature and the findings of the study, this thesis proposes a Self-Sovereign Identity (SSI) and Verifiable Credentials (VC) based system that enables paperless and secure data sharing and management in a decentralised manner among stakeholders involved in the migration process. The proposed solution also includes a mechanism that allows migrants to securely store information related to their cultural heritage using a decentralised approach and independently issue Verifiable Credentials. The system utilises the Cardano blockchain, Hyperledger Identus, and the InterPlanetary File System (IPFS) to ensure decentralisation, privacy protection, data security, data sovereignty, and data integrity. A prototype was developed to demonstrate the feasibility of the approach and was informally evaluated by a small group of migrant users to assess the usability and acceptance of the proposed system.

text: A cardano blockchain prototype for migrant data security and cultural heritage preservation This thesis investigates the challenges faced by migrants in managing and sharing personal data during migration processes, as well as the potential privacy, security, and data sovereignty risks that may arise from poor data management practices or malicious actors. It further examines the difficulties migrants face in preserving their cultural heritage within their host countries.

Migrants are often required to disclose extensive personal and sensitive information to immigration authorities and associated organisations, which raises significant concerns regarding data privacy, data security, and data sovereignty. These issues may result in adverse outcomes, including misuse of data, loss of control over personal information, and the loss of cultural identity. To better understand these challenges, a study was conducted with twenty migrants to explore their experiences with documentation procedures, their awareness of potential privacy risks, and their perspectives on safeguarding cultural heritage information.

Based on insights from existing literature and the findings of the study, this thesis proposes a Self-Sovereign Identity (SSI) and Verifiable Credentials (VC) based system that enables paperless and secure data sharing and management in a decentralised manner among stakeholders involved in the migration process. The proposed solution also includes a mechanism that allows migrants to securely store information related to their cultural heritage using a decentralised approach and independently issue Verifiable Credentials. The system utilises the Cardano blockchain, Hyperledger Identus, and the InterPlanetary File System (IPFS) to ensure decentralisation, privacy protection, data security, data sovereignty, and data integrity. A prototype was developed to demonstrate the feasibility of the approach and was informally evaluated by a small group of migrant users to assess the usability and acceptance of the proposed system.

year: 2026-01-13

title: An investigation of koi carp (Cyprinus carpio) movement in the Waikato region using laser ablation otolith microchemistry

authors: Blair, Jennifer Marie

subjects: Carp

abstract: The koi carp Cyprinus carpio is an invasive fish that has reached high numbers and biomass in the North Island of New Zealand, particularly in the Waikato region. This species has a variety of negative effects on aquatic ecosystems, increasing turbidity, uprooting aquatic macrophytes, and affecting water column
nutrient levels. Recent research in Australia and New Zealand has shown that adult carp, though largely restricted to small scale movements, are capable of moving long distances. Movement in adult carp may be underestimated by these studies, and comparatively little is known about the movement of smaller carp. This study examined the feasibility of using laser ablation otolith microchemistry to track koi carp movement and identify spawning areas.

Water samples from six locations (Lake Waahi, Lake Whangape, Lake Waikare, the Whangamarino River, and the Waikato River at Aka Aka and Rangiriri) were analysed using inductively coupled plasma mass spectrometry (ICP-MS).
Significant differences between sites were found in the water concentrations of many elements. Koi carp were collected from the above locations, as well as from Opuatia Stream, Pungarehu Stream, the Maramarua River and Lake Hakanoa. The elemental concentrations in the asteriscus otoliths were analysed using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP-MS). Elemental concentrations in the edges and nuclei of adult koi carp and the edges
of young-of-the-year (YOY) koi carp were significantly different between capture sites. No significant differences were found in elemental concentrations between sites in the nuclei of YOY koi carp.

A discriminant function analysis (DFA) was carried out using the otolith edge
elemental signatures of koi carp. The model used Ba, Sr, Mg, Rb and Zn concentrations to differentiate between four capture locations: the Waikato River, Pungarehu Stream, Lake Waahi, and Lake Waikare and Pungarehu Stream. The DFA was able to correctly predict the capture location of 82% of koi carp using their otolith edge elemental signatures. 

The classification functions created using koi carp otolith edge signatures were then used as a training set to classify otolith nucleus signatures. The otolith nuclei of 80% of YOY koi carp were classified to their site of capture, suggesting they had not moved between locations. The majority of adult koi carp caught at Lake Waikare, Whangamarino River, Pungarehu Stream and Opuatia Stream had nucleus signatures matching their capture sites, indicating that these fish
originated from their capture location. Koi carp from other sites likely moved there from another location. The majority of adult koi carp (88%) caught at the Waikato River at Rangiriri had otolith nucleus signatures matching Lake Waikare
and Pungarehu Stream. Adult koi carp caught at Lake Waahi and the Waikato River at Aka Aka had otolith signatures corresponding to a range of locations. While some areas (Lake Waikare, Pungarehu Stream) appear to have resident koi
carp populations that likely originated there, others (Lake Waahi, the Waikato River) appear to have koi carp populations of mixed origin. These results indicate that Lake Waikare, Pungarehu Stream and the Whangamarino River may be
important sources of koi carp recruits in the lower Waikato region.

text: An investigation of koi carp (Cyprinus carpio) movement in the Waikato region using laser ablation otolith microchemistry The koi carp Cyprinus carpio is an invasive fish that has reached high numbers and biomass in the North Island of New Zealand, particularly in the Waikato region. This species has a variety of negative effects on aquatic ecosystems, increasing turbidity, uprooting aquatic macrophytes, and affecting water column
nutrient levels. Recent research in Australia and New Zealand has shown that adult carp, though largely restricted to small scale movements, are capable of moving long distances. Movement in adult carp may be underestimated by these studies, and comparatively little is known about the movement of smaller carp. This study examined the feasibility of using laser ablation otolith microchemistry to track koi carp movement and identify spawning areas.

Water samples from six locations (Lake Waahi, Lake Whangape, Lake Waikare, the Whangamarino River, and the Waikato River at Aka Aka and Rangiriri) were analysed using inductively coupled plasma mass spectrometry (ICP-MS).
Significant differences between sites were found in the water concentrations of many elements. Koi carp were collected from the above locations, as well as from Opuatia Stream, Pungarehu Stream, the Maramarua River and Lake Hakanoa. The elemental concentrations in the asteriscus otoliths were analysed using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP-MS). Elemental concentrations in the edges and nuclei of adult koi carp and the edges
of young-of-the-year (YOY) koi carp were significantly different between capture sites. No significant differences were found in elemental concentrations between sites in the nuclei of YOY koi carp.

A discriminant function analysis (DFA) was carried out using the otolith edge
elemental signatures of koi carp. The model used Ba, Sr, Mg, Rb and Zn concentrations to differentiate between four capture locations: the Waikato River, Pungarehu Stream, Lake Waahi, and Lake Waikare and Pungarehu Stream. The DFA was able to correctly predict the capture location of 82% of koi carp using their otolith edge elemental signatures. 

The classification functions created using koi carp otolith edge signatures were then used as a training set to classify otolith nucleus signatures. The otolith nuclei of 80% of YOY koi carp were classified to their site of capture, suggesting they had not moved between locations. The majority of adult koi carp caught at Lake Waikare, Whangamarino River, Pungarehu Stream and Opuatia Stream had nucleus signatures matching their capture sites, indicating that these fish
originated from their capture location. Koi carp from other sites likely moved there from another location. The majority of adult koi carp (88%) caught at the Waikato River at Rangiriri had otolith nucleus signatures matching Lake Waikare
and Pungarehu Stream. Adult koi carp caught at Lake Waahi and the Waikato River at Aka Aka had otolith signatures corresponding to a range of locations. While some areas (Lake Waikare, Pungarehu Stream) appear to have resident koi
carp populations that likely originated there, others (Lake Waahi, the Waikato River) appear to have koi carp populations of mixed origin. These results indicate that Lake Waikare, Pungarehu Stream and the Whangamarino River may be
important sources of koi carp recruits in the lower Waikato region.

year: 2008

title: Te Kōtihitihi: Ngā Tuhinga Reo Māori, Putanga 1

authors: Ngāpō, Korohere

abstract: Koinei te katoa o te Putanga 1 o te puka hautaka, Te Kōtihitihi.

text: Te Kōtihitihi: Ngā Tuhinga Reo Māori, Putanga 1 Koinei te katoa o te Putanga 1 o te puka hautaka, Te Kōtihitihi.

year: 2011-04