To asses effects further away from the sound source, we studied changes in fish behavior and physiology in a laboratory setup featuring a sound system that plays recorded piling sound. In the aquaria, single strike sound levels reached 162 dB re 1 µPa².s and 2400 strikes led to a cumulative sound exposure level of 196 dB re 1 µPa².s. Under these conditions, we observed that normal behavior was disturbed, with an increase in startle responses and stationary behavior at the beginning of the sound exposure but was re-established shortly after the cessation of the sound. Feeding and respiration were not affected and accordingly, feeding conversion efficiency, Fulton’s condition index, length and weight over 15 days were no different than in the ”silent” treatment. The specific growth rate, however, was significantly different between treatments, indicating that food assimilation was decreased due to increased stress levels after exposure.
These results indicate that short-term exposure to impulsive sound creates sound pressure levels at the sound source that are below the lethal sound threshold for fish, but above the stress sound threshold, at least for sea bass smaller than 2 g. Furthermore, the sound levels at a wider range can disturb fish behavior. This disturbance, however, was short-lived and little impact on growth and condition was seen in the conducted experiments.
|Publicatiestatus||Gepubliceerd - 10-mrt.-2015|
|Evenement||Conference on wind energy and wildlife impacts - Berlin, Duitsland|
Duur: 10-mrt.-2015 → 13-mrt.-2015
|Congres||Conference on wind energy and wildlife impacts|
|Periode||10/03/15 → 13/03/15|