title: Parkins v Parkins

authors: Chevalier-Watts, Juliet

abstract: This case came about by appeal from the District Court, which dismissed the appellant’s claim.  The appellant, Grant Parkins (Grant) declared 25% interest by way of institutional constructive trust over a property in the Marlborough Sounds (the property), which is opposed by his brothers, Steven Parkins (Steven) and Reece Parkins (Reece).   Grant states that his interest arises because of his substantial contributions to the property after it was bought by his late father, Morris Parkins (Morris).  The property was substantively developed after its purchase.  The property had been left in equal shares to the three brothers by Morris in his will. Of note is that the terms of Morris’ will were not challenged in any way by any of the brothers. Whilst this case does not challenge the law of institutional constructive trusts, it provides a useful and instructive summary of the established law and thus adds to the institutional constructive trust narrative.  Prior to considering the law, we will first provide an overview of the facts.

text: Parkins v Parkins This case came about by appeal from the District Court, which dismissed the appellant’s claim.  The appellant, Grant Parkins (Grant) declared 25% interest by way of institutional constructive trust over a property in the Marlborough Sounds (the property), which is opposed by his brothers, Steven Parkins (Steven) and Reece Parkins (Reece).   Grant states that his interest arises because of his substantial contributions to the property after it was bought by his late father, Morris Parkins (Morris).  The property was substantively developed after its purchase.  The property had been left in equal shares to the three brothers by Morris in his will. Of note is that the terms of Morris’ will were not challenged in any way by any of the brothers. Whilst this case does not challenge the law of institutional constructive trusts, it provides a useful and instructive summary of the established law and thus adds to the institutional constructive trust narrative.  Prior to considering the law, we will first provide an overview of the facts.

year: 2022-06-01

title: Investigating drivers of cyanobacterial blooms in Aotearoa – New Zealand lakes using sedimentary ancient DNA

authors: Picard, Maïlys

subjects: Cyanobacteria

abstract: Healthy lake ecosystems support biodiversity and human populations. They provide many ecosystem services such as water, food and energy. Lakes can be impacted by natural disturbances, but they are increasingly threatened by human-induced disturbances. Studies have shown that eutrophication and climate change often enhance cyanobacteria over other photosynthetic taxa. As cyanobacterial blooms are becoming more frequent and intense throughout the world, more lake systems are being investigated. In some cases there is not a clear link between eutrophication and cyanobacterial blooms. One such example is Lake Pounui (Wairarapa, New Zealand), which has little intensive agriculture in its catchment but water quality has degraded markedly in the last decade. The lake now experiences heavy cyanobacterial blooms every summer. This could be due to the presence of a non-native fish population, the European perch (Perca fluviatilis). This thesis examined the relationship between cyanobacterial blooms and perch introduction in New Zealand
lakes, including a multi-trophic study in Lake Pounui. Perch were introduced c. 1870 in New Zealand but introduction records are patchy and sometimes non-existent. Moreover, most lake systems are not studied until they are already degraded. This thesis used a combination of traditional proxies (pollen, charcoal, pigments) and modern proxies (sedimentary ancient DNA, XRF scanning) from lake sediment cores to reconstruct lake ecology in pre-human times, after M¯aori settlement between the 13th to 15th century, and after European settlement from 1840 AD. Timelines and intensity of human impact were reconstructed with pollen, charcoal analysis, and sediment dating when possible.

Cyanobacterial communities in six lakes were reconstructed through their sedimentary ancient DNA (sedaDNA) using metabarcoding and droplet digital PCR (ddPCR) in Chapter 2. Bloom-forming species were present in all lakes prior to human arrival; however their overall abundance was low. Total cyanobacteria abundance and richness increased in all lakes after European settlement but was very pronounced in four lakes, where bloom-forming taxa became dominant. The trends in cyanobacterial abundance from ddPCR were then compared to cyanobacterial pigments (canthaxanthin, echinenone, myxoxanthophyll and zeaxanthin) using highperformance liquid chromatography in Chapter 3, to assess the likelihood of the historical increase observed. Pigments / sedaDNA relationships were more consistent when all pigments were summed, which is likely due to differences in species composition across lakes. The positive correlations confirmed an increase in cyanobacterial biomass since European arrival.

Due to patchy records for fish introduction, fish sedimentary DNA was compared to environmental DNA (eDNA) from water samples as a methodological check (Chapter 4) before applying this method to the sediment cores. This study was undertaken in three small and shallow lowland lakes by targeting perch and rudd (Scardinius erythrophthalmus). Fish DNA was evenly distributed across the whole lake except when the fish population was low. Samples collected from the sediment contained fish DNA more often than water samples in two out of the three small shallow lakes (including Lake Pounui). Sediment geochemistry probably impeded detection in the third lake. Perch sedaDNA was therefore used as an indication of fish presence in Lake Pounui for Chapter 5, which explored multitrophic changes in Lake Pounui over the last c. 1,000 years. In addition to pollen, charcoal, and 14C dating, XRF scanning was used to reconstruct mineralogic shifts from the catchment (Ti/inc, K/inc) and within the lake (inc/coh). Biological trends were reconstructed
by targeting the sedaDNA of bacteria (16S rRNA), microeukaryotes (18S rRNA), metazoans (CO1), and macrophytes (rbcL, trnL). Complemented by historical records and studies, the data produced in this thesis indicated that the biggest changes in Lake Pounui happened after European settlement (c. 1845), with land clearance, perch introduction, climate change, and probable fertiliser application driving the degradation of the water quality in c. 180 years. This study revealed shifts in native communities (macrophytes, bacteria, oligochaete worms) and the appearance of new species (perch, macrophytes, freshwater nematodes) previously undocumented using sedaDNA. The results highlight just how complex yet fragile lake ecosystems can be and how little we still know about them. Sedimentary ancient DNA is a useful tool to study the insidious and long-lasting impact of nonnative species on freshwater ecosystems because it widens the range of species that can be studied. However, it needs to be complemented with other proxies. This thesis provides a framework to study fish DNA in small shallow lakes (Chapter 4). It can also inform future management and restoration strategies in lakes, especially in Lake Pounui, by retracing historical water quality (Chapter 2) and identifying taxa present prior to, during, and after lake degradation (Chapter 5).

text: Investigating drivers of cyanobacterial blooms in Aotearoa – New Zealand lakes using sedimentary ancient DNA Healthy lake ecosystems support biodiversity and human populations. They provide many ecosystem services such as water, food and energy. Lakes can be impacted by natural disturbances, but they are increasingly threatened by human-induced disturbances. Studies have shown that eutrophication and climate change often enhance cyanobacteria over other photosynthetic taxa. As cyanobacterial blooms are becoming more frequent and intense throughout the world, more lake systems are being investigated. In some cases there is not a clear link between eutrophication and cyanobacterial blooms. One such example is Lake Pounui (Wairarapa, New Zealand), which has little intensive agriculture in its catchment but water quality has degraded markedly in the last decade. The lake now experiences heavy cyanobacterial blooms every summer. This could be due to the presence of a non-native fish population, the European perch (Perca fluviatilis). This thesis examined the relationship between cyanobacterial blooms and perch introduction in New Zealand
lakes, including a multi-trophic study in Lake Pounui. Perch were introduced c. 1870 in New Zealand but introduction records are patchy and sometimes non-existent. Moreover, most lake systems are not studied until they are already degraded. This thesis used a combination of traditional proxies (pollen, charcoal, pigments) and modern proxies (sedimentary ancient DNA, XRF scanning) from lake sediment cores to reconstruct lake ecology in pre-human times, after M¯aori settlement between the 13th to 15th century, and after European settlement from 1840 AD. Timelines and intensity of human impact were reconstructed with pollen, charcoal analysis, and sediment dating when possible.

Cyanobacterial communities in six lakes were reconstructed through their sedimentary ancient DNA (sedaDNA) using metabarcoding and droplet digital PCR (ddPCR) in Chapter 2. Bloom-forming species were present in all lakes prior to human arrival; however their overall abundance was low. Total cyanobacteria abundance and richness increased in all lakes after European settlement but was very pronounced in four lakes, where bloom-forming taxa became dominant. The trends in cyanobacterial abundance from ddPCR were then compared to cyanobacterial pigments (canthaxanthin, echinenone, myxoxanthophyll and zeaxanthin) using highperformance liquid chromatography in Chapter 3, to assess the likelihood of the historical increase observed. Pigments / sedaDNA relationships were more consistent when all pigments were summed, which is likely due to differences in species composition across lakes. The positive correlations confirmed an increase in cyanobacterial biomass since European arrival.

Due to patchy records for fish introduction, fish sedimentary DNA was compared to environmental DNA (eDNA) from water samples as a methodological check (Chapter 4) before applying this method to the sediment cores. This study was undertaken in three small and shallow lowland lakes by targeting perch and rudd (Scardinius erythrophthalmus). Fish DNA was evenly distributed across the whole lake except when the fish population was low. Samples collected from the sediment contained fish DNA more often than water samples in two out of the three small shallow lakes (including Lake Pounui). Sediment geochemistry probably impeded detection in the third lake. Perch sedaDNA was therefore used as an indication of fish presence in Lake Pounui for Chapter 5, which explored multitrophic changes in Lake Pounui over the last c. 1,000 years. In addition to pollen, charcoal, and 14C dating, XRF scanning was used to reconstruct mineralogic shifts from the catchment (Ti/inc, K/inc) and within the lake (inc/coh). Biological trends were reconstructed
by targeting the sedaDNA of bacteria (16S rRNA), microeukaryotes (18S rRNA), metazoans (CO1), and macrophytes (rbcL, trnL). Complemented by historical records and studies, the data produced in this thesis indicated that the biggest changes in Lake Pounui happened after European settlement (c. 1845), with land clearance, perch introduction, climate change, and probable fertiliser application driving the degradation of the water quality in c. 180 years. This study revealed shifts in native communities (macrophytes, bacteria, oligochaete worms) and the appearance of new species (perch, macrophytes, freshwater nematodes) previously undocumented using sedaDNA. The results highlight just how complex yet fragile lake ecosystems can be and how little we still know about them. Sedimentary ancient DNA is a useful tool to study the insidious and long-lasting impact of nonnative species on freshwater ecosystems because it widens the range of species that can be studied. However, it needs to be complemented with other proxies. This thesis provides a framework to study fish DNA in small shallow lakes (Chapter 4). It can also inform future management and restoration strategies in lakes, especially in Lake Pounui, by retracing historical water quality (Chapter 2) and identifying taxa present prior to, during, and after lake degradation (Chapter 5).

year: 2023

title: Pūtahitanga: The intersection of western science and mātauranga Māori in the context of Aotearoa New Zealand’s physical oceanography

authors: Stevens, Craig L.

subjects: Mātauranga Māori

abstract: Aotearoa New Zealand is a land and cultures surrounded by one of the planet’s larger marine exclusive economic zones per capita. Understanding, living within and utilising this domain requires a well-developed knowledge of the physical oceanography–fate, provenance and transfer of ocean-water, material and energy. In the Aotearoa New Zealand context, understanding and utilising the environment through science also requires that Māori have a stake in the science and a pathway to connecting with their mātauranga. The pūtahitanga (intersection) of mātauranga Māori and western science perspectives brings challenges for implementation of the Vision Mātauranga framework for physical oceanographic science. Here we discuss the drivers and key themes for the pūtahitanga and propose a mahere kaupapa/plan bound by: (i) climate, (ii) decolonisation, (iii) shared language, (iv) data sovereignty, and (v) developing a cohort who can lead the field in the coming decades.

text: Pūtahitanga: The intersection of western science and mātauranga Māori in the context of Aotearoa New Zealand’s physical oceanography Aotearoa New Zealand is a land and cultures surrounded by one of the planet’s larger marine exclusive economic zones per capita. Understanding, living within and utilising this domain requires a well-developed knowledge of the physical oceanography–fate, provenance and transfer of ocean-water, material and energy. In the Aotearoa New Zealand context, understanding and utilising the environment through science also requires that Māori have a stake in the science and a pathway to connecting with their mātauranga. The pūtahitanga (intersection) of mātauranga Māori and western science perspectives brings challenges for implementation of the Vision Mātauranga framework for physical oceanographic science. Here we discuss the drivers and key themes for the pūtahitanga and propose a mahere kaupapa/plan bound by: (i) climate, (ii) decolonisation, (iii) shared language, (iv) data sovereignty, and (v) developing a cohort who can lead the field in the coming decades.

year: 2021