title: The potential for waterbirds to act as a vector for zooplankton dispersal in the North Island, New Zealand

authors: Jamieson, Kelly

subjects: Zooplankton

abstract: Zooplankton are essential components of freshwater ecosystems by controlling algal growth and sustaining higher trophic levels. Freshwater zooplankton are geographically isolated and are incapable of active dispersal to new freshwater sites. The dispersal of zooplankton can occur through natural dispersal vectors (e.g., wind, rain or waterfowl) or through human-mediated dispersal vectors (e.g., accidental or deliberate introductions). Dispersal of zooplankton is vital for maintaining gene flow between isolated sites and colonising new habitats. Zooplankton diapause eggs are well suited for dispersal as they are resistant to harsh conditions, e.g., digestion, drying and freezing. Diapause eggs increase the chance of survival in unfavourable conditions and are an important part of a zooplankton’s life cycle. This paper analyses New Zealand waterbirds’ dispersal of zooplankton internally (endozoochory) and externally (ectozoochory). 

This study quantified the dispersal of zooplankton internally (endozoochory) using the faecal droppings collected from waterbirds at two New Zealand Lakes. Faecal droppings were collected from Mallard Ducks, Canadian Geese, Greylag Geese, Black Swans and Australian Coots from Lake Rotoroa and Lake Rotorua. A total of 50 eggs were found in the faecal droppings of waterbirds, with a mean number of 0.75 eggs found per dropping. These results indicate that waterbirds are consuming zooplankton eggs. However, no significant difference was observed in the propagule count among waterbird species. Therefore it was unlikely that the waterbird species impacted the abundance or viability of diapause eggs. 

The sediment experiment showed zooplankton are inhabiting the shores of Lake Rotorua and Lake Rotoroa, where waterbirds are likely to come in contact with diapause located within the sediment. In Lake Rotorua, diapausing eggs from six species of rotifers, cladocerans, copepods and ostracods hatched from the littoral sediments. Strikingly, no hatching was observed in the littoral sediments from Lake Rotoroa. These results suggest that diapausing eggs are readily available to be picked up by waterbirds for external dispersal (ectozoochory). This study quantified the potential for zooplankton to be dispersed by waterbirds internally (endozoochory) and externally (ectozoochory). Results suggest that waterbird dispersal of zooplankton is occurring, but the numbers being transported are low. Although, the transport of a few individuals may be enough to achieve gene flow. Waterbirds are not be the primary vector for the dispersal of zooplankton. Human-mediated contributions e.g., shipping-related activities (ballast tanks), may play a more significant role than waterbirds in the dispersal of zooplankton.

text: The potential for waterbirds to act as a vector for zooplankton dispersal in the North Island, New Zealand Zooplankton are essential components of freshwater ecosystems by controlling algal growth and sustaining higher trophic levels. Freshwater zooplankton are geographically isolated and are incapable of active dispersal to new freshwater sites. The dispersal of zooplankton can occur through natural dispersal vectors (e.g., wind, rain or waterfowl) or through human-mediated dispersal vectors (e.g., accidental or deliberate introductions). Dispersal of zooplankton is vital for maintaining gene flow between isolated sites and colonising new habitats. Zooplankton diapause eggs are well suited for dispersal as they are resistant to harsh conditions, e.g., digestion, drying and freezing. Diapause eggs increase the chance of survival in unfavourable conditions and are an important part of a zooplankton’s life cycle. This paper analyses New Zealand waterbirds’ dispersal of zooplankton internally (endozoochory) and externally (ectozoochory). 

This study quantified the dispersal of zooplankton internally (endozoochory) using the faecal droppings collected from waterbirds at two New Zealand Lakes. Faecal droppings were collected from Mallard Ducks, Canadian Geese, Greylag Geese, Black Swans and Australian Coots from Lake Rotoroa and Lake Rotorua. A total of 50 eggs were found in the faecal droppings of waterbirds, with a mean number of 0.75 eggs found per dropping. These results indicate that waterbirds are consuming zooplankton eggs. However, no significant difference was observed in the propagule count among waterbird species. Therefore it was unlikely that the waterbird species impacted the abundance or viability of diapause eggs. 

The sediment experiment showed zooplankton are inhabiting the shores of Lake Rotorua and Lake Rotoroa, where waterbirds are likely to come in contact with diapause located within the sediment. In Lake Rotorua, diapausing eggs from six species of rotifers, cladocerans, copepods and ostracods hatched from the littoral sediments. Strikingly, no hatching was observed in the littoral sediments from Lake Rotoroa. These results suggest that diapausing eggs are readily available to be picked up by waterbirds for external dispersal (ectozoochory). This study quantified the potential for zooplankton to be dispersed by waterbirds internally (endozoochory) and externally (ectozoochory). Results suggest that waterbird dispersal of zooplankton is occurring, but the numbers being transported are low. Although, the transport of a few individuals may be enough to achieve gene flow. Waterbirds are not be the primary vector for the dispersal of zooplankton. Human-mediated contributions e.g., shipping-related activities (ballast tanks), may play a more significant role than waterbirds in the dispersal of zooplankton.

year: 2022

title: The general theory of R-separation for Helmholtz equations

authors: Kalnins, Ernie G.

subjects: Mathematics

abstract: We develop the theory of R-separation for the Helmholtz equation on a pseudo-Riemannian manifold (including the possibility of null coordinates) and show that it, and not ordinary variable separation, is the natural analogy of additive separation for the Hamilton–Jacobi equation. We provide a coordinate-free characterization of variable separation in terms of commuting symmetry operators.

text: The general theory of R-separation for Helmholtz equations We develop the theory of R-separation for the Helmholtz equation on a pseudo-Riemannian manifold (including the possibility of null coordinates) and show that it, and not ordinary variable separation, is the natural analogy of additive separation for the Hamilton–Jacobi equation. We provide a coordinate-free characterization of variable separation in terms of commuting symmetry operators.

year: 1983-05

title: Caught in the cross-fire: the realities of being Māori at a bicultural law school

authors: Papuni-Ball, Makere

abstract: This thesis examines the first Waikato Māori Law Graduates’ experiences at law school and our employment choices. It has been written as a result of a research project which was conducted in 1994. The paper begins with establishing the importance of other Māori the guidelines on this project. In this discussion, my role as the researcher is explained together with how the original research project impacted upon this thesis.

Waikato School of Law was established in an era of socio-political changes in our society. Te Matahauariki Report supported its establishment based upon proven demand for law graduates. It also envisaged the School as being a meeting place for all who attended, an institution which might encourage relationships between Māori and Pakeha societies. The Council of Legal Education supported the need to have at least one law school which would not reflect the traditional legal education system and acknowledged the need to incorporate a Māori perspective. Tainui as tangata whenua hoped the school would provide opportunities for Māori students, including Māori in the curriculum and assist in promoting research ensuring the recognition of Māori lore/law.

Amongst this backdrop, the most important reason why we came to law school was because of our whānau expectations. It is the accountability and responsibility we have as Māori to our whānau and the wider Māori community that is a major theme throughout this thesis. As students we were expected to utilise our skills to benefit our wider Māori networks.

We had expected that the School would provide us with a legal education which would be enriched in Māori kaupapa. Our experiences tell another story. Instead of being educated in Māori tikanga and the true discourse of the law as a tool of oppression, we were exposed to continual suppression of our cultural heritage. In class we had become the teachers of the Māori content.

The School, although admiral in its aims, was not prepared in structure, staff or mental processes for biculturalism. The consequences for the Māori students who were exposed to this structure was devastating. Our experiences of being discriminated against and made to justify our Māori perspective against the backdrop of the dominant Pakeha legal culture have affected our perceptions of the law. The myths of one law for all and the neutrality of the justice system have resulted in our choosing to work in jobs that will continue to benefit Māori.

It is suggested that our legal education has influenced our choices to work in areas which focus on benefiting the Māori community. In those monocultural work areas which have few Māori practising, this is because such places repel those of us who know that such work places perpetuate the dominant Pakeha culture. Māori struggle against the oppressive presence of the dominant culture.

This thesis calls upon my own experiences and the experiences of my fellow Māori law graduates. It is a starting point for other Māori to write about their experiences and to reassert Māori rangatiratanga not only in law school, but in the wider community.

text: Caught in the cross-fire: the realities of being Māori at a bicultural law school This thesis examines the first Waikato Māori Law Graduates’ experiences at law school and our employment choices. It has been written as a result of a research project which was conducted in 1994. The paper begins with establishing the importance of other Māori the guidelines on this project. In this discussion, my role as the researcher is explained together with how the original research project impacted upon this thesis.

Waikato School of Law was established in an era of socio-political changes in our society. Te Matahauariki Report supported its establishment based upon proven demand for law graduates. It also envisaged the School as being a meeting place for all who attended, an institution which might encourage relationships between Māori and Pakeha societies. The Council of Legal Education supported the need to have at least one law school which would not reflect the traditional legal education system and acknowledged the need to incorporate a Māori perspective. Tainui as tangata whenua hoped the school would provide opportunities for Māori students, including Māori in the curriculum and assist in promoting research ensuring the recognition of Māori lore/law.

Amongst this backdrop, the most important reason why we came to law school was because of our whānau expectations. It is the accountability and responsibility we have as Māori to our whānau and the wider Māori community that is a major theme throughout this thesis. As students we were expected to utilise our skills to benefit our wider Māori networks.

We had expected that the School would provide us with a legal education which would be enriched in Māori kaupapa. Our experiences tell another story. Instead of being educated in Māori tikanga and the true discourse of the law as a tool of oppression, we were exposed to continual suppression of our cultural heritage. In class we had become the teachers of the Māori content.

The School, although admiral in its aims, was not prepared in structure, staff or mental processes for biculturalism. The consequences for the Māori students who were exposed to this structure was devastating. Our experiences of being discriminated against and made to justify our Māori perspective against the backdrop of the dominant Pakeha legal culture have affected our perceptions of the law. The myths of one law for all and the neutrality of the justice system have resulted in our choosing to work in jobs that will continue to benefit Māori.

It is suggested that our legal education has influenced our choices to work in areas which focus on benefiting the Māori community. In those monocultural work areas which have few Māori practising, this is because such places repel those of us who know that such work places perpetuate the dominant Pakeha culture. Māori struggle against the oppressive presence of the dominant culture.

This thesis calls upon my own experiences and the experiences of my fellow Māori law graduates. It is a starting point for other Māori to write about their experiences and to reassert Māori rangatiratanga not only in law school, but in the wider community.

year: 1996