[MARMAM] New publication: ship noise extends to high frequencies

Scott Veirs info at beamreach.org
Tue Feb 2 13:45:13 PST 2016


We would like to announce that a new paper on underwater source levels 
of 12 classes of ships has been published in the open-access, 
peer-reviewed journal PeerJ.

Veirs S, Veirs V, Wood JD. (2016) Ship noise extends to frequencies used 
for echolocation by endangered killer whales. PeerJ 4:e1657 

Main findings from ~2,800 measurements of ~1,600 unique ships in 12 classes:
-- In the Salish Sea ships dominate the soundscape (~20 ships/day, 
year-round; mean+/-s.d. broadband source level of 173 +/- 7 dB re 1 uPa 
@ 1m)
-- Median noise spectrum levels received in killer whale habitat (2 km 
from shipping lane) were raised 5-30 dB (re 1 uPa^2@/Hz) above 
background by ships at all reported frequencies (11.5 Hz - 40,000 Hz).
-- Source spectra of different ship classes show similar levels above 
20,000 Hz, but bifurcation into lower and higher power groups at lower 
frequencies (~20 dB re 1 uPa^2/Hz @ 1 m difference at the 50 Hz power peak).
-- Container ships have highest median spectrum levels; military ships 
have some of the lowest levels, especially below 1,000 Hz.
-- Within each class, source spectrum levels vary 15-30 dB re 1 uPa^2/Hz 
@ 1 m between the 5% and 95% quantiles.

Supplemental information (R scripts, data, example mp3 files) can be 
accessed here:

We hope this characterization of ship noise will help inform models of 
potential impacts on marine life, development of policies regarding 
ocean noise, and strategies for mitigating noise pollution from ships.

Best regards,
Scott, Val, and Jason

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