title: Averaging underwater noise levels for environmental assessment of shipping.
abstract: Rising underwater noise levels from shipping have raised concerns regarding chronic impacts to marine fauna. However, there is a lack of consensus over how to average local shipping noise levels for environmental impact assessment. This paper addresses this issue using 110 days of continuous data recorded in the Strait of Georgia, Canada. Probability densities of ~10(7) 1-s samples in selected 1/3 octave bands were approximately stationary across one-month subsamples. Median and mode levels varied with averaging time. Mean sound pressure levels averaged in linear space, though susceptible to strong bias from outliers, are most relevant to cumulative impact assessment metrics.
authors.affiliation: Department of Physics, University of Bath, Bath, BA2 7AY, United Kingdom. n.d.merchant@bath.ac.uk
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Merchant
authors.forename: Philippe
authors.initials: P
authors.lastname: Blondel
authors.forename: D Tom
authors.initials: DT
authors.lastname: Dakin
authors.forename: John
authors.initials: J
authors.lastname: Dorocicz
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D016014:Linear Models; D009038:Motion; D009624:Noise, Transportation / Q000009:adverse effects*; D009792:Oceans and Seas; D011312:Pressure; D012767:Ships; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014160:Transducers, Pressure; D014867:Water
chemical_list: D014867:Water