Startle response of captive North Sea fish species to underwater tones between 0.1 and 64 kHz.
World-wide, underwater background noise levels are increasing due to anthropogenic activities. Little is known about the effects of anthropogenic noise on marine fish, and information is needed to predict any negative effects. Behavioural startle response thresholds were determined for eight marine fish species, held in a large tank, to tones of 0.1-64 kHz. Response threshold levels varied per frequency within and between species. For sea bass, the 50% reaction threshold occurred for signals of 0.1-0.7 kHz, for thicklip mullet 0.4-0.7 kHz, for pout 0.1-0.25 kHz, for horse mackerel 0.1-2 kHz and for Atlantic herring 4 kHz. For cod, pollack and eel, no 50% reaction thresholds were reached. Reaction threshold levels increased from approximately 100 dB (re 1 microPa, rms) at 0.1 kHz to approximately 160 dB at 0.7 kHz. The 50% reaction thresholds did not run parallel to the hearing curves. This shows that fish species react very differently to sound, and that generalisations about the effects of sound on fish should be made with care. As well as on the spectrum and level of anthropogenic sounds, the reactions of fish probably depend on the context (e.g. location, temperature, physiological state, age, body size, and school size).
Kastelein
Ronald A
RA
Sea Mammal Research Company, Julianalaan 46, 3843 CC Harderwijk, The Netherlands. researchteam@zonnet.nl
Heul
Sander van der
Sv
Verboom
Willem C
WC
Jennings
Nancy
N
Veen
Jan van der
Jv
de Haan
Dick
D
D000161:Acoustic Stimulation; D000818:Animals; D005399:Fishes / Q000502:physiology*; D006309:Hearing / Q000502:physiology; D009622:Noise / Q000009:adverse effects*; D009659:North Sea; D013216:Reflex, Startle / Q000502:physiology*; D012623:Seawater; D013016:Sound / Q000009:adverse effects; D013045:Species Specificity; D013550:Swimming