Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Marine Mammal Science 25 (2009): 53-67, doi:10.1111/j.1748-7692.2008.00243.x.
Description:
Acoustic harassment and deterrent devices have become increasingly popular mitigation
tools for negotiating the impacts of marine mammals on fisheries. The rationale for their
variable effectiveness remains unexplained but high variability in the surrounding acoustic field
may be relevant. In the present study, the sound fields of one acoustic harassment device and
three acoustic deterrent devices were measured at three study sites along the Scandinavian coast.
Superimposed onto an overall trend of decreasing sound exposure levels with increasing range
were large local variations in sound level for all sources in each of the environments. This
variability was likely caused by source directionality, inter-ping source level variation and multi-path interference. Rapid and unpredictable variations in the sound level as a function of range
deviated from expectations derived from spherical and cylindrical spreading models and
conflicted with the classic concept of concentric zones of increasing disturbance with decreasing
range. Under such conditions, animals may encounter difficulties when trying to determine the
direction to and location of a sound source, which may complicate or jeopardize avoidance
responses.
Description:
The project was funded by the Swedish Fishermen Association, the Swedish Board of Fisheries, Aage V. Jensen Foundations, Danish Forest and Nature Agency, The Nordic Research Council and the Carlsberg Foundation. Additional logistical support was furnished by the Oticon Foundation and Reson A/S. A.D. Shapiro received financial support from the National Defense Science and Engineering Graduate Fellowship and the WHOI Academic Programs Office.
356
Keywords:
Acoustic harassment device (AHD)
;
Acoustic deterrent device (ADD)
;
Non-geometrical acoustic spreading
;
Sound exposure level
;
Multi-path interference
;
Marine mammal-fisheries interactions
;
By-catch
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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