The International Quiet Ocean Experiment is a decade long study which is aimed at exploring the totality of ocean noise, including commercial shipping.
The UNESCO sponsored activity will provide a basis for focusing US regulators, and regulators throughout the world, on the major sound sources in lieu of an undue emphasis on seismic exploration.
Which federal regulatory agencies oversee the commercial shipping industry for their impact on marine mammals?
Do other countries have such agencies?
Look at these sound levels–someone should reguate these guys!
Underwater radiated noise from modern commercial ships
J. Acoust. Soc. Am. Volume 131, Issue 1, pp. 92-103 (2012); (12 pages)
Megan F. McKenna1, Donald Ross2, Sean M. Wiggins1, and John A. Hildebrand1 1Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0205
22404 Loring Street, Box 101, San Diego, California 92109
Underwater radiated noise measurements for seven types of modern commercial ships during normal operating conditions are presented. Calibrated acoustic data (<1000 Hz) from an autonomous seafloor-mounted acoustic recorder were combined with ship passage information from the Automatic Identification System. This approach allowed for detailed measurements (i.e., source level, sound exposure level, and transmission range) on ships of opportunity. A key result was different acoustic levels and spectral shapes observed from different ship-types. A 54 kGT container ship had the highest broadband source level at 188 dB re 1μPa@1m; a 26 kGT chemical tanker had the lowest at 177 dB re 1μPa@1m. Bulk carriers had higher source levels near 100 Hz, while container ship and tanker noise was predominantly below 40 Hz. Simple models to predict source levels of modern merchant ships as a group from particular ship characteristics (e.g., length, gross tonnage, and speed) were not possible given individual ship-type differences. Furthermore, ship noise was observed to radiate asymmetrically. Stern aspect noise levels are 5 to 10 dB higher than bow aspect noise levels. Collectively, these results emphasize the importance of including modern ship-types in quantifying shipping noise for predictive models of global, regional, and local marine environments.
© 2012 Acoustical Society of America