Qualitative Behavioural Assessment as a welfare indicator for farmed Atlantic salmon (Salmo salar) in response to a stressful challenge

  • Key finding:

    Animal welfare assessments are constantly faced with the issue of somehow including an animal's emotional state within their evaluations while still remaining objective in their analysis. Qualitative Behavioural Assessment (QBA), a tool which has been validated within welfare assessments across a variety of terrestrial farmed animals, may provide unique insights into an animal's subjective experiences without compromising scientific rigour. Instead of measuring and assessing explicit, physical behaviours (e.g., how fast an animal moves or how much it eats), QBA focuses on evaluating the overall expressive manner in which an animal carries out those behaviours (e.g., how relaxed or agitated they appear). Despite it's potential, QBA's application within aquaculture remains largely unexplored. Highlights of this study: - 9 tanks of juvenile Atlantic salmon (~80 per tank) were video-recorded systematically every morning over a 7-day period, in the middle of which an invasive sampling event was conducted on the salmon. - The 63 video clips recorded throughout this week were then semi-randomised to avoid predictability and treatment bias for QBA scoring. - Before scoring was carried out, 12 salmon-industry professionals generated a list of 16 qualitative terms (e.g., relaxed, unsettled, agitated, stressed) used to describe various expressive characteristics of salmon behaviour that would then be scored in the QBA. - Another group of 5 observers, with varied experience in salmon farming and who were blind to treatment, then scored these videos using QBA. - QBA scores were significantly different between days the salmon were recorded before and after the intrusive sampling event, with the salmon being regarded as significantly more stressed / agitated / unsettled after sampling. Inter- and intra-observer reliability was also scored as acceptable. -This is the first study to demonstrate QBA's ability to capture changes in the behavioural expression of salmon following exposure to a presumably stressful event, therefore highlighting QBA's potential as a unique welfare indicator for farmed Atlantic salmon.

Links to Open Access Publications or DOI:


Wiese, T. R., Rey Planellas, S., Betancor, M., Haskell, M., Jarvis, S., Davie, A., Wemelsfelder, F., Turnbull, J. F. (2023). Qualitative Behavioural Assessment as a welfare indicator for farmed Atlantic salmon (Salmo salar) in response to a stressful challenge. Frontiers in Veterinary Science, 10. 1-12. doi:10.3389/fvets.2023.1260090