Seabass, trout and salmon were exposed to acute stress (transport and dip vaccination), and to chronic stress (high temperature and stocking densities). Physiological and molecular responses were characterised thus improving our understanding of how fish cope with farming practices and environmental changes. Whiteleg shrimp physiological and behavioural responses to stress were also characterised, and new welfare indicators for this species were proposed.
Datasets from stress experiments were integrated and analysed with machine-learning methods to identify consistent patterns linked to stress and immune activation. The analysis has highlighted candidate biomarkers for non-invasive monitoring of fish health and welfare, supporting earlier detection of problems in farms.
A dedicated biorefinery process is being scaled up to produce sufficient extracts for bioactives testing. The process has been patented, to secure efficient conversion of Salicornia ramosissima green fibres into fermentable sugars for downstream production of protein-rich feed additives. Selected extracts were assessed for antimicrobial activity, and were further evaluated in vitro, ex vivo, and in vivo in all fish and shrimp species. These studies confirmed biological activity and supported the selection of top candidates for functional feed development, to enhance health and resilience under farming-relevant stressors, including heat waves.
In salmon, combinations of intraperitoneal injection and dip vaccination were tested to enhance protection against Tenacibaculum finmarkense, while work continues with commercial ISA vaccines combined with drug treatments. OMV-based vaccination approaches were advanced. Vesicles carrying truncated PorU antigens from T. maritimum were successfully produced, and the innovation was secured through a provisional patent. Uptake of OMVs after oral delivery was demonstrated in seabass and trout, and vaccination trials in seabass showed immune responses after intraperitoneal administration. Oral delivery showed more variable responses, indicating potential but also need for further optimisation.
A key output has been the creation and validation of the first SNP array for the Manila clam, providing a powerful resource for genetic analyses, selective breeding, and resilience studies. In parallel, multiomics and molecular phenotyping pipelines have been optimized to integrate transcriptomic, metabolomic, and proteomic data, enabling a comprehensive assessment of fish responses to challenges.
Biosensors for cortisol and other biomarkers detection were developed, as well as machine-vision models and data-driven IT platforms. By enabling non-invasive sampling and real-time monitoring, these tools reduce handling and other stressful procedures, providing actionable insights for farmers.
