Impact of air gun noise on the behaviour of marine fish and squid

► Captive fish and squid were exposed to varying levels of air gun noise. ► Behavioural observations were made before, during and after noise exposure. ► As noise level increased fish swam faster, in tighter groups and deeper in the cage. ► Increases in alarm responses were observed at noise levels >147-151 dB re 1 μPa SEL. ► The proportion of alarm responses increased with increasing noise level.