title: The influence of harvest frequency and regime on the performance of  Filamentous Algae Nutrient Scrubbers treating agricultural drainage

authors: Waaka, Okeroa

subjects: Filamentous algae nutrient scrubbers

abstract: Filamentous algae nutrient scrubbers (FANS) are ecologically engineered flow-ways that have recently been proposed as a potential on-farm method to treat agricultural drainage in New Zealand. The effectiveness of FANS systems to remove nutrients from polluted waters and to produce algal biomass as a harvestable by-product is heavily influenced by operational parameters. As filamentous algae grow on a flow-way, the thickness of the algal biomass increases and begins to reduce light penetration and nutrient assimilation. Therefore, periodic harvesting of the accumulated algal biomass plays a key role in determining the biomass production and nutrient removal performance of FANS systems. 

The overall aim of this study was to investigate the influence of harvest frequency and harvest regime on biomass productivity and nutrient removal of an outdoor FANS system. The FANS system used in this study consisted of six flow-ways that were split into two sets of triplicate flow-ways named “FULL” and “PARTIAL”. Harvesting of the FULL replicate flow-ways occurred once a week, where algal biomass accumulated along the entirety of the flow-way was collected. Harvesting of the PARTIAL replicate flow-ways occurred twice a week, where the algal biomass was collected in alternate meter sections (a total of 3-metre harvest length every 3 – 3.5 days). 

The increased harvest frequency (3 – 3.5 days) and sectioned harvest regime implemented in the PARTIAL replicate flow-ways significantly improved biomass productivity (3.2 g DW m-2. d) in comparison to the less frequent (7 – 7.5 days) and total harvest regime implemented in the FULL replicate flow-ways (0.9 g DW m-2. d). However, there was no significant difference in nutrient removal rates between the PARTIAL and FULL replicate flow-ways. There is still limited understanding of how operational parameters can be optimized to maximise biomass productivity and nutrient removal in FANS systems on a year-round basis. However, the findings of this study demonstrate that an increased harvest frequency and sectioned harvest regime can improve the biomass yield of filamentous algae grown on an outdoor FANS system during spring to summer months. 

Furthermore, this study has suggested the potential for Māori acceptance of FANS technology and algal biomass use. In person interviews with whanau and iwi members recalled use of algal biomass harvested from rivers and streams as fertilizer for vegetable gardens or bait for eel trapping. Moreover, the literature review and in person interviews highlighted the importance of identifying and using ngā kupu (words and terms) used by Māori to describe freshwater algae. The intergenerational observation and utilization of algae as a resource by Māori may reveal an awareness of biological processes that either differs or compliments a Western Science point of view. Incorporating this knowledge into current water and environmental management practices could be extremely beneficial for improving water quality of streams in Aotearoa New Zealand.

text: The influence of harvest frequency and regime on the performance of  Filamentous Algae Nutrient Scrubbers treating agricultural drainage Filamentous algae nutrient scrubbers (FANS) are ecologically engineered flow-ways that have recently been proposed as a potential on-farm method to treat agricultural drainage in New Zealand. The effectiveness of FANS systems to remove nutrients from polluted waters and to produce algal biomass as a harvestable by-product is heavily influenced by operational parameters. As filamentous algae grow on a flow-way, the thickness of the algal biomass increases and begins to reduce light penetration and nutrient assimilation. Therefore, periodic harvesting of the accumulated algal biomass plays a key role in determining the biomass production and nutrient removal performance of FANS systems. 

The overall aim of this study was to investigate the influence of harvest frequency and harvest regime on biomass productivity and nutrient removal of an outdoor FANS system. The FANS system used in this study consisted of six flow-ways that were split into two sets of triplicate flow-ways named “FULL” and “PARTIAL”. Harvesting of the FULL replicate flow-ways occurred once a week, where algal biomass accumulated along the entirety of the flow-way was collected. Harvesting of the PARTIAL replicate flow-ways occurred twice a week, where the algal biomass was collected in alternate meter sections (a total of 3-metre harvest length every 3 – 3.5 days). 

The increased harvest frequency (3 – 3.5 days) and sectioned harvest regime implemented in the PARTIAL replicate flow-ways significantly improved biomass productivity (3.2 g DW m-2. d) in comparison to the less frequent (7 – 7.5 days) and total harvest regime implemented in the FULL replicate flow-ways (0.9 g DW m-2. d). However, there was no significant difference in nutrient removal rates between the PARTIAL and FULL replicate flow-ways. There is still limited understanding of how operational parameters can be optimized to maximise biomass productivity and nutrient removal in FANS systems on a year-round basis. However, the findings of this study demonstrate that an increased harvest frequency and sectioned harvest regime can improve the biomass yield of filamentous algae grown on an outdoor FANS system during spring to summer months. 

Furthermore, this study has suggested the potential for Māori acceptance of FANS technology and algal biomass use. In person interviews with whanau and iwi members recalled use of algal biomass harvested from rivers and streams as fertilizer for vegetable gardens or bait for eel trapping. Moreover, the literature review and in person interviews highlighted the importance of identifying and using ngā kupu (words and terms) used by Māori to describe freshwater algae. The intergenerational observation and utilization of algae as a resource by Māori may reveal an awareness of biological processes that either differs or compliments a Western Science point of view. Incorporating this knowledge into current water and environmental management practices could be extremely beneficial for improving water quality of streams in Aotearoa New Zealand.

year: 2023

title: Changes in the pronunciation of Māori and implications for teachers and learners of Māori

authors: Keegan, Peter J.

subjects: pronunciation of Maori

abstract: This paper discusses changes in the pronunciation of Māori and implications for teachers and learners of Māori. Data on changes in the pronunciation of Māori derives from the MAONZE project (Māori and New Zealand English with support from the Marsden fund). The project uses recordings from three sets of speakers to track changes in the pronunciation of Māori and evaluate influence from English. Results from the project show changes in both vowel quality and vowel duration and some evidence of diphthong mergers in pairs such as ai/ae and ou/au, especially amongst the younger speakers. In terms of duration the younger speakers are producing smaller length distinctions between long/short vowel pairs other than /ā, a/. We discuss the implications of such changes for those teaching Māori and for students learning Māori as a subject. These changes raise interesting questions concerning the pronunciation of Māori by future generations.

text: Changes in the pronunciation of Māori and implications for teachers and learners of Māori This paper discusses changes in the pronunciation of Māori and implications for teachers and learners of Māori. Data on changes in the pronunciation of Māori derives from the MAONZE project (Māori and New Zealand English with support from the Marsden fund). The project uses recordings from three sets of speakers to track changes in the pronunciation of Māori and evaluate influence from English. Results from the project show changes in both vowel quality and vowel duration and some evidence of diphthong mergers in pairs such as ai/ae and ou/au, especially amongst the younger speakers. In terms of duration the younger speakers are producing smaller length distinctions between long/short vowel pairs other than /ā, a/. We discuss the implications of such changes for those teaching Māori and for students learning Māori as a subject. These changes raise interesting questions concerning the pronunciation of Māori by future generations.

year: 2009

title: Strengthening flood governance in Aotearoa New Zealand: Achieving multi-level policy coherence

authors: Hanna, Christina Jane

abstract: Effective flood risk management in Aotearoa New Zealand requires more directive and coherent governance across all levels. This includes clear national direction and policy frameworks for natural hazards and climate change adaptation planning.

text: Strengthening flood governance in Aotearoa New Zealand: Achieving multi-level policy coherence Effective flood risk management in Aotearoa New Zealand requires more directive and coherent governance across all levels. This includes clear national direction and policy frameworks for natural hazards and climate change adaptation planning.

year: 2025