IMR project to study fish reactions to sound
The 8m long, oil filled array, houses eight omni-directional identical hydrophones. The array is designed to be deployed to depths of 100m
A research project being carried out by the Institute of Marine Research (IMR) in Bergen to map the sound field inside a fish pen at Austevoll is using three 8m long, active hydrophone arrays designed by Chelsea Technologies Group Ltd.
The reactions of a school of herring (ca. 10000 fish) to waterborne acoustic signals and noise of various types is currently being studied to get a better understanding of the environmental impact human-made noise can have on fish. The primary objective of the project is to gain an understanding of the interaction between direct stimuli and the information transfer between individuals in schooling fish, and to understand how this affects their behaviour.
Tim Cato Netland, technical engineer at the Norwegian University of Science and Technology (NTNU) said, “The marine acoustics team at NTNU are responsible for the acoustic modelling and instrumentation on the penned herring project. We have conducted several experiments in the Trondheim fjord, leading to an optimised underwater acoustic transmittance and transfer of data. The use of the Chelsea acoustic arrays has greatly simplified the testing process”.
The research involves observing the collective behaviour of penned herring and investigating the effect of various sound stimuli. An area of particular interest is to understand how information is transferred in animals groups, and how stimuli is amplified or dampened through social interactions.
The project will perform lab experiments on schooling fish in response to external stimuli, and investigate the role of the social interactions. The fish will be observed using video cameras, and techniques to extract the behavioural information will be further developed.
An important aspect of the proposal is to establish a link between the highly controlled laboratory observations to in situ experiments. The results from the laboratory will be used to form rigorous hypotheses on the collective behavioural rules in herring, a key species both economically and ecologically. These will be tested on herring in a net pen setup. We will use both video cameras and acoustic cameras to observe the behaviour, and the methods developed from the laboratory experiments will be refined to fit the herring net-pen system.
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