title: Consumption of submerged aquatic macrophytes by rudd (scardinius erythrophthalmus L.) in New Zealand

authors: Lake, Michael D.

subjects: aquatic macrophytes

abstract: In experiments in New Zealand, rudd (Scardinius erythrophthalmus L.) of 108–277mm fork length (FL) ate a wide range of native and introduced submerged aquatic macrophytes in captivity and in the field. Rudd consumed the native charophytes Chara globularis Thuill., Chara fibrosa Ag. ex Bruz., and Nitella spp., the native macrophytes Potamogeton ochreatus Raoul. and Myriophyllum propinquum A. Cunn., and the introduced macrophytes Elodea canadensis Michx., Egeria densa Planch., Lagarosiphon major L., and Ceratophyllum demersum L. Rudd consistently consumed the Nitella spp. and Potamogeton ochreatus before Ceratophyllum demersum. From the results of experiments in tanks and in the field, we found the order of highest to lowest palatability was: Nitella spp. > Potamogeton ochreatus > Elodea canadensis> Chara globularis = Chara fibrosa> Egeria densa = Lagarosiphon major > Myriophyllum propinquum > Ceratophyllum demersum. The order of consumption was subject to some variation with season, especially for Egeria densa, Lagarosiphon major, and Myriophyllum propinquum. Rudd
consumed up to 20% of their body weight per day of Egeria densa in spring, and 22% of their body weight per day of Nitella spp. in summer. Consumption rates were considerably lower in winter than in summer. The results of our field trial suggested that the order of consumption also applies in the field and that rudd are having a profound impact on vulnerable native aquatic plant communities in New Zealand. Nitella spp. and Potamogeton ochreatus are likely to be selectively eaten, and herbivory by rudd might prevent the re-establishment of these species in
restoration efforts.

text: Consumption of submerged aquatic macrophytes by rudd (scardinius erythrophthalmus L.) in New Zealand In experiments in New Zealand, rudd (Scardinius erythrophthalmus L.) of 108–277mm fork length (FL) ate a wide range of native and introduced submerged aquatic macrophytes in captivity and in the field. Rudd consumed the native charophytes Chara globularis Thuill., Chara fibrosa Ag. ex Bruz., and Nitella spp., the native macrophytes Potamogeton ochreatus Raoul. and Myriophyllum propinquum A. Cunn., and the introduced macrophytes Elodea canadensis Michx., Egeria densa Planch., Lagarosiphon major L., and Ceratophyllum demersum L. Rudd consistently consumed the Nitella spp. and Potamogeton ochreatus before Ceratophyllum demersum. From the results of experiments in tanks and in the field, we found the order of highest to lowest palatability was: Nitella spp. > Potamogeton ochreatus > Elodea canadensis> Chara globularis = Chara fibrosa> Egeria densa = Lagarosiphon major > Myriophyllum propinquum > Ceratophyllum demersum. The order of consumption was subject to some variation with season, especially for Egeria densa, Lagarosiphon major, and Myriophyllum propinquum. Rudd
consumed up to 20% of their body weight per day of Egeria densa in spring, and 22% of their body weight per day of Nitella spp. in summer. Consumption rates were considerably lower in winter than in summer. The results of our field trial suggested that the order of consumption also applies in the field and that rudd are having a profound impact on vulnerable native aquatic plant communities in New Zealand. Nitella spp. and Potamogeton ochreatus are likely to be selectively eaten, and herbivory by rudd might prevent the re-establishment of these species in
restoration efforts.

year: 2002

title: Trade, migration, poverty and inequality: A global perspective

authors: Abdul Ghani, Rosmaiza Binti

subjects: Bilateral trade

abstract: Trade and migration have been extensively studied in a variety of disciplines but their inter relationship is still arguable. It is crucial to understand how trade and migration are linked, since they are important elements in a modern, globalized economy. This thesis presents three interconnected studies on trade and migration that make use of newly estimated international migration flows data, to understand these relationships and the potential contributions of trade and migration to global poverty and inequality reduction. The first study examines the bi-directional relationship between trade and migration using international bilateral trade and migration flows data within a seemingly unrelated regression gravity model framework. The study finds that trade and migration are complements, which means that larger migration flows are associated with higher trade flows, and vice versa. Although these results do not definitively demonstrate causality, they suggest that, if world trade decreases due to countries implementation on current protectionist policies, migration flows might also be likely to decline. The second study extends the investigation by examining the causal relationship between trade and migration. The study uses a novel instrumental variables strategy, utilising World Trade Organisation (WTO) affiliation and average tariff rates as instruments within a gravity model framework, to overcome endogeneity in the regression model. The results suggest that trade is a causal driver of migration. This means that migration flows would increase following an increase in trade flows. The third study investigates whether international trade or migration has a larger effect on global extreme poverty and inequality. Again, an instrumental variables approach is used to address any endogeneity problems. The results suggest that trade has a larger potential impact on reducing extreme poverty and inequality. Overall, the outcomes of this thesis are important to policy makers in countries where growing migration is a political issue, and to origin countries that want to restrict the mobility of migrants and reduce the brain drain from their countries. It suggests that how countries treat their borders influences poverty and income inequality outcomes. This thesis suggests that trade provides a greater impact than migration on extreme poverty as well as inequality. Therefore, a country might want to allow freer trade by reducing their national border barriers, in order to reduce extreme poverty and inequality.

text: Trade, migration, poverty and inequality: A global perspective Trade and migration have been extensively studied in a variety of disciplines but their inter relationship is still arguable. It is crucial to understand how trade and migration are linked, since they are important elements in a modern, globalized economy. This thesis presents three interconnected studies on trade and migration that make use of newly estimated international migration flows data, to understand these relationships and the potential contributions of trade and migration to global poverty and inequality reduction. The first study examines the bi-directional relationship between trade and migration using international bilateral trade and migration flows data within a seemingly unrelated regression gravity model framework. The study finds that trade and migration are complements, which means that larger migration flows are associated with higher trade flows, and vice versa. Although these results do not definitively demonstrate causality, they suggest that, if world trade decreases due to countries implementation on current protectionist policies, migration flows might also be likely to decline. The second study extends the investigation by examining the causal relationship between trade and migration. The study uses a novel instrumental variables strategy, utilising World Trade Organisation (WTO) affiliation and average tariff rates as instruments within a gravity model framework, to overcome endogeneity in the regression model. The results suggest that trade is a causal driver of migration. This means that migration flows would increase following an increase in trade flows. The third study investigates whether international trade or migration has a larger effect on global extreme poverty and inequality. Again, an instrumental variables approach is used to address any endogeneity problems. The results suggest that trade has a larger potential impact on reducing extreme poverty and inequality. Overall, the outcomes of this thesis are important to policy makers in countries where growing migration is a political issue, and to origin countries that want to restrict the mobility of migrants and reduce the brain drain from their countries. It suggests that how countries treat their borders influences poverty and income inequality outcomes. This thesis suggests that trade provides a greater impact than migration on extreme poverty as well as inequality. Therefore, a country might want to allow freer trade by reducing their national border barriers, in order to reduce extreme poverty and inequality.

year: 2020

title: Disabled Māori and disability support options

authors: Nikora, Linda Waimarie

subjects: Maori

abstract: The goal of this research project was to provide information to enhance the development and implementation of an effective model of disability support service provision to Maori with disabilities. This was done by identifying and documenting the needs expressed by disabled Maori and their carers living in the Midland area, and by considering the experiences and observations of a key informant group. From our reading of the literature and the feedback we received from participants, a proposed model of disability support service provision has been proposed.

In five sections, this report begins by defining disability, and also by defining the act of caring for the disabled. Focussing on the Maori experience, obstacles, access to existing support services, cultural barriers, and health policies are discussed. In the second chapter, the research methodology is described, along with how the information was gathered. Following this is the third section which presents the opinions and reflections of Maori with disabilities. It concludes strategically with a view of the ideal community, suggesting possible resolutions, by exposing current flaws and inadequacies. Chapter four records the views and perspectives of key informant/whanau carers who participated in the project. They offer an insightful account of the often unrecognised side of the disability experience. Considering the preceding discussions, the final section develops a model of service provision for Maori with disabilities, and proposes this for effective service delivery.

text: Disabled Māori and disability support options The goal of this research project was to provide information to enhance the development and implementation of an effective model of disability support service provision to Maori with disabilities. This was done by identifying and documenting the needs expressed by disabled Maori and their carers living in the Midland area, and by considering the experiences and observations of a key informant group. From our reading of the literature and the feedback we received from participants, a proposed model of disability support service provision has been proposed.

In five sections, this report begins by defining disability, and also by defining the act of caring for the disabled. Focussing on the Maori experience, obstacles, access to existing support services, cultural barriers, and health policies are discussed. In the second chapter, the research methodology is described, along with how the information was gathered. Following this is the third section which presents the opinions and reflections of Maori with disabilities. It concludes strategically with a view of the ideal community, suggesting possible resolutions, by exposing current flaws and inadequacies. Chapter four records the views and perspectives of key informant/whanau carers who participated in the project. They offer an insightful account of the often unrecognised side of the disability experience. Considering the preceding discussions, the final section develops a model of service provision for Maori with disabilities, and proposes this for effective service delivery.

year: 2004-01-01