TY - JOUR
TI - Pile Driving Zone of Responsiveness Extends Beyond 20 km for Harbour Porpoises (Phocoena phocoena (L.))
AU - Tougaard, J
AU - Carstensen, J
AU - Teilmann, J
AU - Skov, H
AU - Rasmussen, P
T2 - Journal of the Acoustical Society of America
AB - Behavioral reactions of harbor porpoises (Phocoena phocoena) to underwater noise from pile driving were studied. Steel monopile foundations (4 m diameter) for offshore wind turbines were driven into hard sand in shallow water at Horns Reef, the North Sea. The impulsive sounds generated had high sound pressures [source level 235 dB re 1 μPapp at 1 m, transmission loss 18 log(distance)] with a strong low frequency emphasis but with significant energy up to 100 kHz. Reactions of porpoises were studied by passive acoustic loggers (T-PODs). Intervals between echolocation events (encounters) were analyzed, and a significant increase was found from average 5.9 h between encounters in the construction period as a whole to on average 7.5 h between first and second encounters after pile driving. The size of the zone of responsiveness could not be inferred as no grading in response was observed with distance from the pile driving site but must have exceeded 21 km (distance to most distant T-POD station).
DA - 2009/03//
PY - 2009
VL - 26
IS - 1
SP - 11
EP - 14
UR - http://scitation.aip.org/content/asa/journal/jasa/126/1/10.1121/1.3132523
DO - 10.1121/1.3132523
LA - English
KW - Wind Energy
KW - Fixed Offshore Wind
KW - Noise
KW - Marine Mammals
ER -