title: An investigation into the commercial feasibility of Jasus edwardsii aquaculture in New Zealand

authors: Ruru, Ian Hector

subjects: New Zealand

abstract: In 1996 New Zealand introduced legislation to allow Jasus edwardsii pueruli to be collected as "seedstock" and ongrown in a commercial aquaculture trial. The aim of this thesis was to investigate the commercial feasibility of J. edwardsii aquaculture in New Zealand by working with an organisation involved in the trial.
The methodology involved a combination of experiments in the field, in laboratories, and within an ongrowing facility. This thesis examined five key areas and found the following:
1. Data obtained in the research indicates that New Zealand will continue to rely on harvesting pueruli from the wild since significant technical obstacles remain in the development of commercial scale pueruli hatcheries. Forecast data, obtained using the delphi technique and information about current research on larval rearing, indicates that commercial scale supply of pueruli from hatcheries may occur between 2017 and 2021.
2. Harvesting trials collected a low number of pueruli with the lowest unit cost for collection being $1.80. A greater collection rate could be achieved with a better understanding of seasonal and local settlement patterns.
3. Survival rates in pueruli transporting experiments were significantly affected by stocking density, time and temperature. The safest transit conditions were achieved with 15 pueruli per litre for less than 6 hours at 14°C.
4. A range of stocking densities, from 3 lobsters per tank to 12 per tank, were tested for their effect on growth of six-month old lobsters. The lobsters were reared in a total recirculation seawater system at a constant 16°C, and fed fresh mussels (Perna canaliculus). For the 121 day trial, no statistically significant effect was detected. However, there was a trend for growth rates to be highest at 3 and 6 lobsters per tank and for growth rates at stocking densities of 9 and 12 lobsters per tank to decrease after Day 50. Lobsters showed increased mortality at the highest stocking rate.
5. A bioeconomic model of a hypothetical farm was developed to assess economic benefits and risks and to determine overall profitability. The model showed an annual net cash position of $287,100 and cumulative cash position of $859,200 by the 10th year of operation based on annual sales of 10,837 kg at $65 per kg. The model indicates that the highest cost components in the first 10 years are processing and transport, and labour. Based on the model and the scenarios examined, profitability is very sensitive to factors such as the farm size, processing and transport costs, and sale price. Biological factors such as growth rates, survival, and feed requirements also influence overall profitability. Good returns will depend upon consistent exports of high quality lobsters.
The study concludes that commercial feasibility will be affected by these key areas. The potential of J. edwardsii aquaculture in New Zealand will continue to benefit from further research.

text: An investigation into the commercial feasibility of Jasus edwardsii aquaculture in New Zealand In 1996 New Zealand introduced legislation to allow Jasus edwardsii pueruli to be collected as "seedstock" and ongrown in a commercial aquaculture trial. The aim of this thesis was to investigate the commercial feasibility of J. edwardsii aquaculture in New Zealand by working with an organisation involved in the trial.
The methodology involved a combination of experiments in the field, in laboratories, and within an ongrowing facility. This thesis examined five key areas and found the following:
1. Data obtained in the research indicates that New Zealand will continue to rely on harvesting pueruli from the wild since significant technical obstacles remain in the development of commercial scale pueruli hatcheries. Forecast data, obtained using the delphi technique and information about current research on larval rearing, indicates that commercial scale supply of pueruli from hatcheries may occur between 2017 and 2021.
2. Harvesting trials collected a low number of pueruli with the lowest unit cost for collection being $1.80. A greater collection rate could be achieved with a better understanding of seasonal and local settlement patterns.
3. Survival rates in pueruli transporting experiments were significantly affected by stocking density, time and temperature. The safest transit conditions were achieved with 15 pueruli per litre for less than 6 hours at 14°C.
4. A range of stocking densities, from 3 lobsters per tank to 12 per tank, were tested for their effect on growth of six-month old lobsters. The lobsters were reared in a total recirculation seawater system at a constant 16°C, and fed fresh mussels (Perna canaliculus). For the 121 day trial, no statistically significant effect was detected. However, there was a trend for growth rates to be highest at 3 and 6 lobsters per tank and for growth rates at stocking densities of 9 and 12 lobsters per tank to decrease after Day 50. Lobsters showed increased mortality at the highest stocking rate.
5. A bioeconomic model of a hypothetical farm was developed to assess economic benefits and risks and to determine overall profitability. The model showed an annual net cash position of $287,100 and cumulative cash position of $859,200 by the 10th year of operation based on annual sales of 10,837 kg at $65 per kg. The model indicates that the highest cost components in the first 10 years are processing and transport, and labour. Based on the model and the scenarios examined, profitability is very sensitive to factors such as the farm size, processing and transport costs, and sale price. Biological factors such as growth rates, survival, and feed requirements also influence overall profitability. Good returns will depend upon consistent exports of high quality lobsters.
The study concludes that commercial feasibility will be affected by these key areas. The potential of J. edwardsii aquaculture in New Zealand will continue to benefit from further research.

year: 2000

title: Protecting Māori data: Can a Privacy Code of Practice provide a partial solution?

authors: Watts, David

abstract: This paper explores whether a Māori Data Privacy Code, developed under the Privacy Act 2020, could provide additional protection for classes of information that are regarded by Māori as tapu. The Act already covers the personal information of Māori individuals in the same way it does any other individual. We argue that a MDP Code could offer additional protection for particular classes of sensitive personal information – specifically whakapapa data and data pertaining to deceased Māori. A MDP Code could restrict the purposes for which such information can be collected, used, disclosed, retained, stored and disposed of; put stronger requirements on agencies to demonstrate that their collection and use of this information is justified; require free, prior and informed consent for its use and disclosure; and provide for greater transparency and independent Māori oversight.

text: Protecting Māori data: Can a Privacy Code of Practice provide a partial solution? This paper explores whether a Māori Data Privacy Code, developed under the Privacy Act 2020, could provide additional protection for classes of information that are regarded by Māori as tapu. The Act already covers the personal information of Māori individuals in the same way it does any other individual. We argue that a MDP Code could offer additional protection for particular classes of sensitive personal information – specifically whakapapa data and data pertaining to deceased Māori. A MDP Code could restrict the purposes for which such information can be collected, used, disclosed, retained, stored and disposed of; put stronger requirements on agencies to demonstrate that their collection and use of this information is justified; require free, prior and informed consent for its use and disclosure; and provide for greater transparency and independent Māori oversight.

year: 2025-10

title: A sustainable solution for nitrate pollution in New Zealand's drinking water capacitive deionization (CDI)

authors: Sharma , Anisha

abstract: Abstract
This study investigates the performance, feasibility, and practical implications of a small-scale
Capacitive Deionization (CDI) system for simultaneous NaCl and Na₂NO₃ removal from water,
focusing on rural and agricultural applications in New Zealand. Seven trials were conducted under
varying ionic loads, flow rates, and voltages, with operational parameters and removal efficiencies
recorded. Conductivity and nitrate concentration trends were closely monitored, revealing high nitrate
removal rates (up to 79.8%) and significant conductivity reduction across multiple cycles.
The system demonstrated stable adsorption–desorption patterns, with minimal fouling and
rapid regeneration. Comparative cost analysis with Reverse Osmosis (RO) and Ion Exchange
indicated CDI’s substantial economic advantage, with a cost per litre of 0.61 cents, over five times
lower than RO, combined with reduced energy consumption (1.97 NZD/year). Beyond water
treatment, the recovered nitrate stream presents an opportunity for agricultural reuse, reducing
nitrogen fertilizer costs and contributing to nutrient recycling.
The results confirm CDI’s adaptability for low-resource settings, offering a low-maintenance,
scalable, and environmentally sustainable alternative for decentralized water treatment. Furthermore,
derived performance metrics highlighted consistent removal efficiency even under varying salinity
conditions, supporting its resilience for fluctuating feedwater qualities common in rural supplies.
Integrating CDI into farm-level water management could enhance water quality and soil nutrient
availability, supporting sustainable farming practices. Future research should focus on long-term field
trials, optimization of electrode materials for mixed-ion selectivity, and system integration with
renewable energy sources to further reduce operating costs and environmental impact.

text: A sustainable solution for nitrate pollution in New Zealand's drinking water capacitive deionization (CDI) Abstract
This study investigates the performance, feasibility, and practical implications of a small-scale
Capacitive Deionization (CDI) system for simultaneous NaCl and Na₂NO₃ removal from water,
focusing on rural and agricultural applications in New Zealand. Seven trials were conducted under
varying ionic loads, flow rates, and voltages, with operational parameters and removal efficiencies
recorded. Conductivity and nitrate concentration trends were closely monitored, revealing high nitrate
removal rates (up to 79.8%) and significant conductivity reduction across multiple cycles.
The system demonstrated stable adsorption–desorption patterns, with minimal fouling and
rapid regeneration. Comparative cost analysis with Reverse Osmosis (RO) and Ion Exchange
indicated CDI’s substantial economic advantage, with a cost per litre of 0.61 cents, over five times
lower than RO, combined with reduced energy consumption (1.97 NZD/year). Beyond water
treatment, the recovered nitrate stream presents an opportunity for agricultural reuse, reducing
nitrogen fertilizer costs and contributing to nutrient recycling.
The results confirm CDI’s adaptability for low-resource settings, offering a low-maintenance,
scalable, and environmentally sustainable alternative for decentralized water treatment. Furthermore,
derived performance metrics highlighted consistent removal efficiency even under varying salinity
conditions, supporting its resilience for fluctuating feedwater qualities common in rural supplies.
Integrating CDI into farm-level water management could enhance water quality and soil nutrient
availability, supporting sustainable farming practices. Future research should focus on long-term field
trials, optimization of electrode materials for mixed-ion selectivity, and system integration with
renewable energy sources to further reduce operating costs and environmental impact.

year: 2026-01-27