Effects of Chronic Boat Noise on the Physiology of the European Seabass (Dicentrarchus labrax)

Acoustic pollution is increasingly recognized as a significant stressor in marine ecosystems, fundamentally altering the underwater soundscape and affecting fish behavior, physiology, and overall fitness. This study investigates the physiological responses of European seabass (Dicentrarchus labrax) to chronic exposure to boat noise, a prevalent form of anthropogenic disturbance in coastal environments. Experimental groups included a control (no sound exposure) and a treatment group exposed to chronic boat noise through underwater speakers. To assess the impact of noise as a stressor, several biomarkers were measured, with a primary focus on cortisol levels across multiple tissues: plasma, gonads, scales, and fins. In addition, secondary stress indicators such as hematocrit and leukocyte formula in blood and glucose and lactate in plasma were analyzed to detect potential systemic alterations caused by prolonged acoustic exposure. The results of this study may provide insight into the physiological effects of boat noise on D. labrax, contributing to a broader understanding of how anthropogenic sound pollution may affect fish health and stress regulation mechanisms in marine environments.