Anna Schmid Bjørgea, Kine Østnes Hansen,a, Terje Vasskog,a, Marthe Jenssen,b and Ingvild Wathne a br’
a Natural Products and Medicinal Chemistry Research Group, Department of Pharmacy, UiT the Arctic University of
Norway, Tromsø, Norway
b Department of Marine Biotechnology, Norwegian Institute of Food, Fisheries and Aquaculture research (Nofima),
Tromsø, Norway
Email: abj088@uit.no
Fishing and aquaculture have been central to Norwegian culture and economy for generations. In modern times, the sector continues to experience strong growth driven by international demand. Atlantic cod is still primarily wild-caught, and export value is expected to plateau due to natural resource limitations. Thus, Norwegian cod farming is undergoing a revival, but biological and quality challenges still limit sustainable growth. Reports note high mortality linked to intestinal inflammation, skeletal/swim bladder deformities, fatty liver with green discoloration, and poor fillet texture/color (1). There is solid evidence that lipids can drive (or strongly modulate) these problems. For example: Fatty liver in cod is tightly linked to high-lipid diets (2, 3). And: fillet quality (texture/color during storage) depends on lipid content/class and oxidation state and diet oil source and lipid quality influence product quality traits in cod (4). While lipids are known to influence/drive these problematic processes, the detailed involvement of lipid profiles remains unclear. Lipidomics, the comprehensive profiling of lipid classes and lipid species, can reveal lipidome signatures of health, stress, nutrition, and disease. Although high-resolution mass spectrometry (HR-MS) enables advanced lipidomics, applications in cod have largely focused on toxicology or narrow biochemical pathways (2, 5, 6), leaving broader questions of fish welfare and fillet quality unanswered and highlighting a gap between modern molecular tools and their practical use in cod aquaculture.
This project will develop robust, tissue-appropriate standard operating procedures (SOPs) for lipid-extraction for key cod matrices, like skin, liver and white muscle, that are fully compatible with downstream LC–HRMS lipidomics. Lipid extraction from biomass is challenging because the lipidome spans a wide polarity/lipophilicity range (from highly polar phospholipids to neutral triacylglycerols), and complex matrices can cause selective losses or co-extraction biases. Therefore, it is essential to optimize an extraction protocol that ensures reproducible, broad-coverage recovery of lipid classes so the measured profile truly represents the whole lipidome and supports reliable conclusions. This will de-risk and enable a precise comparison between e.g. healthy and inflamed intestine by minimizing pre-analytical variance.
We will benchmark five standard extraction systems, e.g. dichloromethane/methanol:H₂O and isopropanol, across the target tissues. Key extraction parameters, like solvent volume, biomass amount, extraction time, number of extractions, shaking, and sonication, will be evaluated. All parameters are selected to be evaluated based on parameters evaluated in the development of comparable extraction protocols from different fish species and extraction theory. LC–Orbitrap-MS (ESI+, reversed phase) runs on extracts from each tissue/protocol will confirm chromatographic behavior, ionization efficiency, and identification depth.
References 1 Kristoffersen S, et al. Oppdrettstorsk – status og utfordringer. Nofima; 2025. 2 Eide M, et al. Integrative omics-analysis of lipid metabolism regulation by peroxisome proliferator-activated receptor a and b agonists in male Atlantic cod. Front Physiol. 2023;14. 3 Kjær MA, et al. Characterisation of lipid transport in Atlantic cod (Gadus morhua) when fasted and fed high or low fat diets. Aquaculture. 2009;288(3-4):325–36. 4 Suárez-Medina MD, et al. The Effect of Low Temperature Storage on the Lipid Quality of Fish, Either Alone or Combined with Alternative Preservation Technologies. Foods. 2024;13(7). 5 Khan EA, et al. Quantitative transcriptomics, and lipidomics in evaluating ovarian developmental effects in Atlantic cod (Gadus morhua) caged at a capped marine waste disposal site. Environ Res. 2020;189. 6 Dale K, et al. Proteomics and lipidomics analyses reveal modulation of lipid metabolism by perfluoroalkyl substances in liver of Atlantic cod (Gadus morhua). Aquat Toxicol. 2020;227.