to him.
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I would like to announce our latest publication in Marine Ecology Progress
Series
(MEPS). It is entitled
Behavioural reactions of free-ranging porpoises and seals to the noise of
a simulated 2 MW windpower generator
MEPS 265: 263-273
If you want a pdf-copy of the full article, please mail to
[EMAIL PROTECTED]
Abstract: Operational underwater noise emitted at 8 m s?1 by a 550 kW
WindWorld wind-turbine was recorded from the sea and modified to simulate
a 2 MW wind-turbine. The sound was replayed from an audio CD through a car
CD-player and a J-13 transducer. The maximum sound energy was emitted
between 30 and 800 Hz with peak source levels of 128 dB (re 1 µPa2 Hz?1 at
1 m) at 80 and 160 Hz (1/3-octave centre frequencies). This simulated 2 MW
wind-turbine noise was played back on calm days (<1 Beaufort) to
free-ranging harbour porpoises Phocoena phocoena and harbour seals Phoca
vitulina in Fortune Channel, Vancouver Island, Canada. Swimming tracks of
porpoises and surfacings of seals were recorded with an electronic
theodolite situated on a clifftop 14 m above sea level. Echolocation
activity of harbour porpoises close to the sound source was recorded
simultaneously via an electronic click detector placed below the
transducer. In total we tracked 375 porpoise groups and 157 seals during
play-back experiments, and 380 porpoise groups and 141 surfacing seals
during controls. Both species showed a distinct reaction to wind-turbine
noise. Surfacings in harbour seals were recorded at larger distances from
the sound source (median = 284 vs 239 m during controls; p = 0.008,
Kolmogorov-Smirnov test) and closest approaches increased from a median of
120 to 182 m (p < 0.001) in harbour porpoises. Furthermore, the number of
time intervals during which porpoise echolocation clicks were detected
increased by a factor of 2 when the sound source was active (19.6% of all
1 min intervals as opposed to 8.4% of all intervals during controls; p <
0.001).These results show that harbour porpoises and harbour seals are
able to detect the low-frequency sound generated by offshore
wind-turbines. Controlled exposure experiments such as the one described
here are a first step to assess the impact on marine mammals of the new
offshore wind-turbine industry.
key words: Harbour porpoise · Phocoena phocoena · Harbour seal · Phoca
vitulina · Noise · Offshore windpower · Environmental assessment
authors: Sven Koschinski, Boris M. Culik, Oluf Damsgaard Henriksen, Nick
Tregenza, Graeme Ellis, Christoph Jansen, Günter Kathe
source: MEPS 265: 263-273
Sven Koschinski
Kuehlandweg 12
24326 Nehmten
Germany
[EMAIL PROTECTED]
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