Evaluation of contaminant interactions using integrative high-throughput technology for aquafeed safety

The composition of Atlantic salmon feed have gone through tremendous changes from being almost completely marine-based fifteen years ago, to the current fish feed containing 70% plant ingredients. Pesticides are used worldwide to increase food production and aquaculture feed producers buy their plant ingredients in a global market. Results show that the pesticides accumulate in zebrafish and that PB, the adjuvant, affects the accumulation. Because our aim was to compare responses in different biological models, a new cell model trial using 3D primary Atlantic salmon hepatocytes has been performed. Cells have been exposed singly or in combination to the adjuvant PB and the pesticides chlorpyrifos-methyl and pirimiphos-metyl to identify possible interaction effects in pesticide mixtures with focus on mode of action pathways. Today there are no feeding studies with pirimiphos-methyl in salmon or other fish species. Data from such studies can be used to set maximum limits in feed ingredients and fish feed (fish health and seafood safety). A sub-chronic toxicological dose-response feeding trial with pirimifos-methyl with Atlantic salmon has been performed and show a dose response effect on growth, blood heamatology, plasma enzymes, and lipid composition. Analyses on omics, including lipidomics are currently in progress. A feed-to-fillet transfer model has been developed from our data. Omics data from the different work packages will now be collected and bioinformatics tools developed to perform the multi-omics approach.

The integration of multiscale data from the salmon lipidome, transcriptome and proteome has broaden our understanding on contaminant interactions. We have also found new lipid mediators of inflammation from the eicosanoid, endocannabinoid and sphingolipid pathways in salmon exposed to pesticides. We have established a feed-to-fillet transfer model for Atlantic salmon that can be used for other contaminants. The overall outcomes of this project will contribute with important knowledge for risk assessment of plant-derived contaminants for fish health and human health as well as harmonization of legislation of pesticides and adjuvangts throughout the seafood production chain.

The composition of Atlantic salmon feed have gone through tremendous changes from being almost completely marine-based fifteen years ago, to the current fish feed containing 70% plant ingredients. Pesticides are used worldwide to increase food production and aquaculture feed producers buy their plant ingredients in a global market. Thus, plant ingredients contain contaminants not earlier associated with salmon farming. Norway, as one of the leading seafood nations, can through this project contribute with pivotal knowledge on the impact of contaminants in plant-based fish feed on fish health and human health. In the proposed project we will take advantage of the salmon genome and state of the art systems biology tools expertise, as well as knowledge from ongoing EU projects on new contaminants in novel salmon feed. The integration of multiscale data from the salmon lipidome, transcriptome and proteome will broaden our understanding on contaminant interactions. Atlantic salmon health will be addressed by investigating altered lipid deposition, lipid accumulation and muscle quality as well as evaluating new affected pathways using lipid-and proteomics. Effects on the salmon immune system will be addressed by investigating lipid mediators of inflammation from the eicosanoid, endocannabinoid and sphingolipid pathways. The possible impact on human health will be addressed by assessing bioavailability and accumulation kinetics to be used in a feed-to-fillet transfer model for Atlantic salmon. We will establish sensitive methodologies for contaminant and metabolite accumulation using liquid chromatography coupled to tandem mass spectrometry. The overall outcomes of this project will contribute with important knowledge for risk assessment of plant-derived contaminants for fish health and human health as well as harmonization of legislation of contaminants throughout the seafood production chain.