Dear Colleagues,
Those of you interested in the effects of underwater noise on aquatic life may be interested in our recent Open Access publication in Scientific Reports:
Underwater noise levels in UK waters (2016)
Nathan D. Merchant, Kate L. Brookes, Rebecca C. Faulkner, Anthony W. J. Bicknell, Brendan J. Godley & Matthew J. Witt
Scientific Reports 6, Article number: 36942
http://www.nature.com/articles/srep36942
Abstract: Underwater noise from human activities appears to be rising, with ramifications for acoustically sensitive marine organisms and the functioning of marine ecosystems. Policymakers are beginning to address the risk of ecological
impact, but are constrained by a lack of data on current and historic noise levels. Here, we present the first nationally coordinated effort to quantify underwater noise levels, in support of UK policy objectives under the EU Marine Strategy Framework Directive
(MSFD). Field measurements were made during 2013–2014 at twelve sites around the UK. Median noise levels ranged from 81.5–95.5 dB re 1 μPa for one-third octave bands from 63–500 Hz. Noise exposure varied considerably, with little anthropogenic influence at
the Celtic Sea site, to several North Sea sites with persistent vessel noise. Comparison of acoustic metrics found that the RMS level (conventionally used to represent the mean) was highly skewed by outliers, exceeding the 97th percentile at some frequencies.
We conclude that environmental indicators of anthropogenic noise should instead use percentiles, to ensure statistical robustness. Power analysis indicated that at least three decades of continuous monitoring would be required to detect trends of similar magnitude
to historic rises in noise levels observed in the Northeast Pacific.
Kind regards,
Nathan
Dr Nathan Merchant
Principal Scientist, Noise & Bioacoustics Team
Pakefield Road, Lowestoft, Suffolk, NR33 0HT, UK
Tel: +44(0) 1502 527780 | Mob: +44 (0) 7789 651086
Email:
https://scholar.google.co.uk/citations?user=XPctSoUAAAAJ&hl=en
https://www.cefas.co.uk/services/research-advice-and-consultancy/underwater-noise/
https://www.cefas.co.uk/media/52916/noise-bioacoustics.pdf
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