Aquaculutre in action: Dr Simon Muncaster is part of a team fine-tuning fish farming practices to breed Kingfish for commercial farming.
Fish farming in New Zealand is currently limited to salmon, oysters and mussels, but scientists at the University of Waikato and Bay of Plenty Polytechnic are keen to see kingfish added to the list of commercially farmed fish.
Discovering the finer details
Dr Steven Bird, a molecular biologist recently arrived from Scotland, and Dr Simon Muncaster, a New Zealander who completed his doctorate in Norway, have teamed up to discover the finer detail required to successfully breed kingfish in captivity.
Dr Bird says kingfish are already farmed in Australia and Japan, but there are still a lot of issues around deformity and disease in the farming environment. “So we’re trying to find out the ideal conditions for breeding – things like water temperature, diet and how the fish respond to stress.”
Dr Muncaster is a specialist in fish reproductive physiology. He has a good working relationship with scientists at NIWA in Northland who have been breeding kingfish and supplying him with fertilised eggs for research.
“Kingfish grow quickly, which is good for commercial farming, but there are usually a few challenges associated with developing new aquaculture species and this is where we are interested in focusing our research efforts.”
For example, growth often slows down in farmed fish because they reach maturity early under farmed conditions, and this means that a lot of their energy is wasted on reproduction rather than growth before the fish are harvested.
A skilled team
“It is often more evident in one sex than the other. One of our interests is to investigate the process of sexual differentiation in kingfish to see when and how they start developing either male or female characteristics. This could help us to produce fish of the same sex to maximise growth and to stop unwanted breeding, which can be important from an environmental point of view.”
Dr Muncaster says this is already being done in other successfully farmed species and has nothing to do with genetic modification.
“To achieve this though, we will need to rear more kingfish in our Tauranga aquaculture facility. This is a job that requires a skilled team as kingfish larvae are fairly basic and very fragile to start with. We have to produce two different types of zooplankton to feed the larvae and take great care over their environmental conditions so they can successfully metamorphise into juvenile kingfish.”
Quick results
At Waikato University, Dr Bird is using biomarkers - traits that can be used to identify the progress of a disease or condition - and testing genetic level responses to external changes in the environment. The University has provided preliminary funding to obtain the biomarkers that will allow them to look at the genes.
“With this technology we can get results in months not years,” says Dr Bird. “The information we get allows us to monitor responses to environmental changes and in turn fine tune farming practices during the different growth phases.”
Dr Bird says if New Zealand wants to expand its commercial aquaculture base, then it needs to increase the number of species being farmed.
“Ideally, industry players would come on board to support the research but I’m also aware that there will be RMA issues and other consent processes that could potentially detract from expanding fish farming here. But there are also very real opportunities and what we learn in our study could be applied to other species.”
For more stories on research and innovation at the University of Waikato, see the latest issue of re:think.