Studying fish reaction to sound
The 8m oil filled array can be deployed to depths of 100m
The Norwegian University of Science and Technology (NTNU) has been working with the UK’s marine sensor manufacturer, Chelsea Technologies Group (CTG), to design an acoustic hydrophone array in order to study the impact of human noise on fish and other aquatic organisms.
CTG says there is growing interest in understanding the effects of human generated sound on fish. Boats and ships are a major source of noise, as well as sonar systems used by navies, shipping companies, fishing industries and the oceanographic research community. Pile driving for the windfarm industry seismic airgun arrays is also a high intensity source.
CTG initially designed a 6m vertical acoustic hydrophone array to conduct underwater acoustic experiments. This was followed by the design of three 8m long, active hydrophone arrays which are now being used to map the sound field inside a fish pen at Austevoll, south of Bergen.
Nils Olav Handegard, marine researcher, NTNU, told World Fishing & Aquaculture: "The reason for the study is to obtain a better understanding of how sound affects schooling behavior in Atlantic herring, a keystone species in the Norwegian Sea. Since sound propagates much better in water than air, sound pollution is potentially a larger issue for aquatic organisms than in terrestrial systems. In order to understand the human footprint on our marine ecosystem, a better understanding of how various aquatic animals responds to sound is needed."
The NTNU has conducted several experiments in the Trondheim fjord, leading to an optimised underwater acoustic transmittance and transfer of data.