Exploring the future of marine farming in New Zealand under climate change conditions: using sea surface temperature

This study explores and provides new insight in to how the increase in sea surface temperature as a result of climate change may affect the marine farming industry and coastal zone management of New Zealand. As the world’s population grows and the effects of climate change intensify there will be a greater demand for sustainable food resources. Aquaculture can provide our growing population with this resource as long as there is effective environmental management. Policy and decision makers must review and consider the full array of effects climate change may have on the coastal zone and aquaculture. A marine farmer questionnaire was developed to gain insight into how current marine farmers viewed important variables in marine farm site selection and climate change. A number of GIS techniques were used to identify what species are at risk of experiencing water temperatures that exceed their physiological threshold. A simple agent-based model was developed to estimate the potential loss in the numbers of those animals that may experience extreme water temperatures. Lastly, a suitability analysis was developed to identify alternative sites for farming the at risk species. A majority of marine farmers rated some important physical and social variables in marine farm site selection as less important than farmers 15 years ago. A majority of marine farmers feel they are somewhat informed and have little concern for climate change. The King Salmon is at risk of experiencing water temperatures that exceed its physiological threshold. Around 15-66% of the salmon currently being farmed in the Marlborough Sounds could be lost to water temperature greater than 17°C. Alternative sites for farming salmon are located in the middle-lower regions of the South Island, New Zealand under the IPPC’s A2 and B1 emissions scenarios. The findings from this research are useful to organisations such as Aquaculture NZ and the Marine Farming Association in planning for the future of the industry. These findings are also useful to policy and decision makers for developing effective management strategies and in marine space allocation in the wake of climate change. This is a novel study for New Zealand, as very little research has been undertaken to explore the effects of climate change on the aquaculture industry and coastal zone management. Based on the results the current literature gaps in the body of knowledge are filled. It also provides a solution to help mitigate the effects of climate change for decision makers and those farms that are may experience extreme water temperatures.