A new study from Scottish start-up SalmoSim indicates insects used to break down plastic waste could be viable protein sources for farmed Atlantic salmon.
The study showed protein produced from plastic-fed wax worms had the same digestibility when analysed by SalmoSim as compared to other commercially available feeds.
SalmoSim is an in-vitro model of the Atlantic salmon’s gut system established and based at the University of Glasgow.
Originally developed to study the salmon’s gut microbiome, SalmoSim says it is now deploying a novel assay named “SalmoSim Digest” which predicts the digestibility of alternative ingredients alongside a model for the absorption of nutrients by the fish.
As part of the testing process, SalmoSim says waxworms were maintained with a diet of either LDPE plastic (cling film) or a traditional balanced diet while waxworm growth was monitored – waxworms fed LDPE gained weight compared to unfed controls.
The need to find alternative, sustainable and low-cost feedstocks for farmed fish has never been greater.
SalmoSim says that compared to other insect meals, and benchmarked against fish meal, waxworms could be an important source of feed for salmon and further testing is now required to establish the safety of salmon fed on plastic-fed waxworms.
Commenting on the findings of the study, Martin Llewellyn, Professor of Molecular Ecology at Glasgow University and Founding Director of SalmoSim, said: “We are hugely encouraged by this data which indicate waxworms used to break down plastic could be a potential source of protein for farmed Atlantic salmon.
“As the pressure on wild fish stocks used for fish meal continues to grow, the need to find alternative, sustainable and low-cost feedstocks for farmed fish has never been greater.
“While the next step is to ensure that plastic-fed wax worms pose no toxicity to salmon, and can safely enter the human food chain, there is clearly exciting potential here and we look forward to continuing with our research into sustainable protein sources for farmed Atlantic salmon.”