Supplementary material from "Microplastic content and using food waste-fed insects in fish feed influence appeal of farmed fish"

Although aquaculture can contribute to food security, its high dependency on wild-caught fish as feed has urged the sector to turn to sustainable alternative feed sources. Larvae of black soldier flies fed on food waste represent a sustainable alternative to fish feed. Yet, there remains uncertainty on how consumers would respond to food waste-reared insect-fed farmed fish. Here, we carried out a discrete choice experiment in Singapore (n = 600) to investigate consumers’ preferences for alternative feed sources (wild-caught fish, insects fed with plants, insects fed with pre-/post-consumer food waste), microplastic content, CO2 emissions and origin. We found a general reluctance to purchase insect-fed farmed fish, especially if the insects are fed with post-consumer food waste. Nonetheless, if the feed is produced locally and if the microplastics content is lowered, insect-fed fish could become more appealing. Results further suggest greater purchase intention of fish farmed with alternative feeds among university degree holders. Compared to females, males appear readier to buy farmed fish fed with insects reared on post-consumer food waste. Overall, these results contribute to revealing how consumer preferences for novel aquafeeds, informing sustainable aquaculture marketing and policy.