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.
