NZ is the largest producer of king salmon (Oncorhynchus tshawytscha) in the world, with an annual aquaculture production of 14kt worth around $130 million NZD. Improving feed conversion efficiency (FCE) and health are key priorities for the sector. For reasons we do not understand yet, king salmon’s FCE is considerably poorer than that for many other species of fish, and there is considerable scope for improvements to be made. To gain new insights into processes that influence king salmon’s FCE, an integrated systems biology approach is being conducted by our multidisciplinary team, covering environmental interactions, fish behaviour, health, histology, gut microbiomics, genetics, blood biochemistry, and metabolomics, among others. Before initiating our experimental trials to understand how each fish responds to changes in its environment and feed under controlled settings, we are conducting an extensive survey of salmon from across NZ’s farms over different seasons, life-stages, family genetics, culture conditions, and environments to obtain important baseline information for this species. We have collected around 350 fish to date, with dissections yielding over 4000 samples for different analyses. Preliminary GC/MS- and NMR-based metabolomics data is allowing us to begin piecing together the king salmon metabolome, establish reference values, and discern natural biological variability. We envision that metabolomics will provide valuable information to improve FCE in fish, potentially though metabolic trait identifications for selective breeding purposes, incorporation of tracer-based techniques to investigate nutritional uptake/partitioning and energetics, and for functional genomic assessments. Our king salmon FCE project will equip farmers with the knowledge needed to improve on farm production, supporting the future growth of this sustainable industry.