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

• Published in: Marine pollution bulletin 2012-05, Vol.64 (5), p.984-993
• Main Authors: Fewtrell, J.L., McCauley, R.D.
• Format: Article
• Language: English
• Subjects: Airgun; Animals; Behavior, Animal - physiology; Behaviour; coasts; Decapodiformes - physiology; Firearms; Fish; Fishes - physiology; Marine; marine fish; Noise; Noise - adverse effects; Seawater - chemistry; sounds; Squid; squids; swimming; water pollution
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2012.02.009

► 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 >147–151dB re 1μPa SEL. ► The proportion of alarm responses increased with increasing noise level. In this study various species of captive marine fish and one species of squid were exposed to the noise from a single air gun. Six trials were conducted off the coast of Western Australia with each trial using a different noise exposure regime. Noise levels received by the animals ranged between 120 and 184dBre1μPa2.s (SEL). Behavioural observations of the fish and squid were made before, during and after air gun noise exposure. Results indicate that as air gun noise levels increase, fish respond by moving to the bottom of the water column and swimming faster in more tightly cohesive groups. Significant increases in alarm responses were observed in fish and squid to air gun noise exceeding 147–151dBre1μPa SEL. An increase in the occurrence of alarm responses was also observed as noise level increased.