Researchers found that selectively bred Australasian snapper (Chrysophrys auratus) performed better in farmed environments than wild-caught snapper across both land-based and ocean-based system.
The study comes as rising sea temperatures challenge the viability of Chinook salmon farming, currently the sole species underpinning New Zealand’s ocean-based finfish aquaculture industry.
In recent years, summer water temperatures in the top of the South Island have repeatedly exceeded 18°C, contributing to marine heatwaves and significant salmon mortality events.
Producers are increasingly exploring climate-adapted alternatives suited to warmer conditions.
Dr Maren Wellenreuther, who led the research, emphasised that traditional finfish aquaculture faces mounting pressure as sea temperatures increase.
“New Zealand’s finfish aquaculture sector currently relies on salmon, which are known to be sensitive to temperature change. By finding new species to grow in aquaculture settings, the seafood sector can not only expand its offering to consumers but also develop resilience to changes in the climate.”
This research demonstrated that sea-pen farming was a highly feasible production system for snapper.
Snapper is closely related to red sea bream from Japan and gilthead sea bream in the Mediterranean.
Both are among the most successfully cultured species in their regions and have potential to become the next major bream species for aquaculture in New Zealand.
As a warm-water species, snapper grow well under local conditions and display strong survival and performance traits, even in regions increasingly affected by marine heatwaves.
The research was conducted by a team from the New Zealand Institute for Plant and Food Research and the School of Biological Sciences, University of Auckland. The findings were published in the New Zealand Journal of Marine and Freshwater Research.
Faster growth in farmed environment
The breeding programme selected parent fish in each generation based on traits favourable for aquaculture production, such as growth and survival in captivity.
Both groups were reared in two farming systems: sea pens in the Marlborough Sounds and land-based tank systems. Across both environments, selectively bred snapper demonstrated superior biological performance.
In land-based systems, selectively bred fish recorded a 1.7 per cent increase in body length and a 9.8 per cent improvement in body weight relative to wild fish.
In sea pens, gains were more pronounced, with body length increasing by 4.8 per cent and body weight by 14.2 per cent.
Survival rates also rose significantly. In land-based tanks, survival improved by 84.2 per cent, while sea-pen systems saw a 60.8 per cent increase compared to wild fish.
“These results demonstrate that selective breeding can produce snapper that are not only faster-growing but also more resilient to environmental stressors, offering a climate-adapted solution for aquaculture. Our findings show that snapper could play a key role in future-proofing aquaculture in Aotearoa New Zealand,” said Georgia Samuels, first author on the research publication.
The researchers suggested that future research should focus on using selective breeding to boost snapper aquaculture, aiming to improve growth rates and strengthen the species’ resilience to colder water conditions.
Samuels, G., Ashton, D., Ford, S., Fantham, J., Blommaert, J., Moran, D., & Wellenreuther, M. (2025). Selective breeding and production strategies to support snapper farming in the warming waters of New Zealand’s South Island. New Zealand Journal of Marine and Freshwater Research. https://doi.org/10.1002/nzm2.70011