The Effect of Boat Noise on the Physiology and Behavior of European Seabass (Dicentrarchus labrax)

Acoustic pollution is a significant stressor in aquaculture, affecting fish welfare and productivity, particularly in species like European seabass (Dicentrarchus labrax). This study examined the effects of various boat noise types on seabass stress responses, focusing on cortisol as a key biomarker, measured across plasma, muscle, mucus, and fins. While plasma and mucus cortisol levels were highly responsive to noise, muscle and fin cortisol showed more nuanced patterns, with fins being sensitive to unfamiliar sounds, highlighting their potential as medium-term stress indicators. Behavioral responses were also analyzed using video recordings and AI tools. The findings revealed no significant influence of sex or weight on stress responses. Elevated cortisol levels in unfamiliar noise conditions underscore the need for noise management strategies in aquaculture to enhance fish welfare. Non-invasive cortisol measurement methods, such as using mucus and fins, offer practical tools for welfare monitoring. Future research should explore chronic noise exposure's effects on fish health and productivity.