TY - JOUR
TI - Underwater Noise From Three Types Of Offshore Wind Turbines: Estimation Of Impact Zones For Harbor Porpoises And Harbor Seals
AU - Tougaard, J
AU - Henriksen, O
AU - Miller, L
T2 - Journal of the Acoustical Society of America
AB - Underwater noise was recorded from three different types of wind turbines in Denmark and Sweden (Middelgrunden, Vindeby, and Bockstigen-Valar) during normal operation. Wind turbine noise was only measurable above ambient noise at frequencies below 500 Hz. Total sound pressure level was in the range 109-127 dB re 1 μPa rms, measured at distances between 14 and 20 m from the foundations. The 1/3-octave noise levels were compared with audiograms of harbor seals and harbor porpoises. Maximum 1/3-octave levels were in the range 106-126 dB re 1 μPa rms. Maximum range of audibility was estimated under two extreme assumptions on transmission loss (3 and 9 dB per doubling of distance, respectively). Audibility was low for harbor porpoises extending 20-70 m from the foundation, whereas audibility for harbor seals ranged from less than 100 m to several kilometers. Behavioral reactions of porpoises to the noise appear unlikely except if they are very close to the foundations. However, behavioral reactions from seals cannot be excluded up to distances of a few hundred meters. It is unlikely that the noise reaches dangerous levels at any distance from the turbines and the noise is considered incapable of masking acoustic communication by seals and porpoises.
DA - 2009/01//
PY - 2009
VL - 125
IS - 6
SP - 3766
EP - 3773
UR - https://asa.scitation.org/doi/full/10.1121/1.3117444
DO - 10.1121/1.3117444
LA - English
KW - Wind Energy
KW - Fixed Offshore Wind
KW - Noise
KW - Marine Mammals
KW - Pinnipeds
ER -