Fish robustNess: a key element of population vulnerability and sustainable aquaculture – FISHNESS

FishNess investigates individual fish robustness as a determinant of population vulnerability and aquaculture sustainability in the face of major global change stressors, warming and hypoxia. Robustness is a core concern for agricultural sustainability in the face of global change. It is measured as the ability to allocate energy towards growth and reproduction under prevailing environmental conditions, and the extent to which this ability is resilient to perturbation by extreme climatic events. Robustness in fishes requires intensive study because it has important implications for both wild and farmed populations.
FishNess combines experimental biology, genomics and modelling, in a case study on a valuable species for fisheries and farming, the European sea bass. The species has three genetically distinct populations, in the Atlantic, Western Mediterranean and Eastern Mediterranean. FishNess will reproduce these in captivity from existing broodstock and rear them over two years, under three seasonal thermal regimes that reflect each population’s range, in a full-factorial design. Individual and populational diversity in robustness will be investigated, as temperature-related allocation of energy to growth, reproduction and physiological performance; and as resilience to summer heatwaves and hypoxic events. The heritable component of variation in traits of robustness will be evaluated with a 57K SNP chip for sea bass, to investigate genotype by environment interactions in each population and existence of local adaptation. Integration of phenotypic information into the dynamic energy budget (DEB) paradigm will be used to project individual outcomes for life history traits such as growth, maturation and reproduction, while accounting for costs of coping with environmental stress. Outputs from individual DEB models, and estimates of their genomic heritability, will be used in evolutionary models to predict robustness to various future scenarios in wild and domesticated populations, across multiple generations.
The results will help preserve fish stocks by revealing population short-term coping capacity and long-term adaptability, and consequences for future stock productivity. They will promote sustainable aquaculture by identifying robust populations, starting genomic selection on robustness, and projecting productivity in future climates.