Rencontre SFA // Strasbourg // 3 décembre 2013 Effects of sonar and killer whale sounds playbacks on sperm whales’ behaviour S ea M ammal Charlotte Curé R esearch cc201@st-andrews.ac.uk University U nit of St Andrews P a t r i c k M i l l e r ‘ s L a b // U n i v e r s i t y o f S t - A n d r e w s // S c o t l a n d
I n t r o d u c t i o n Ocean anthropogenic noise = acoustic pollution for many aquatic animals like cetaceans. Fishing boat Ocean mapping Ship noise Naval sonar Oil drilling platform Sonar sounds
I n t r o d u c t i o n Naval sonar : long and loud exposure, in the frequency range of cetaceans’ sounds . Effects on : - Physiology echolocation/acoustic - Behaviour communication : essential for surviving Sonar Pilot whale vocalizations LFAS Frequency (kHz) 2 1 0.4 Time (s) 12
Why KW playbacks? 3S project: investigate and quantify the potential disturbance effects of naval sonar on cetaceans ’ behaviour. Predator vocalizations Sonar exposure (LFAS/MFAS) (Killer Whale playbacks) Interpretation Reactions of cetaceans of the = model of disturbance behavioural changes? Hypothesis: the behavioural changes induced by sonar is similar to a stress triggered by predation risk. Animals have evolved anti predator behaviours and this adaptation may influence how they respond to other potential threats (Frid A. and Dill. L. 2002, 2007).
Field work in the North Atlantic May-July Spitzberg Jan Mayen Lofoten
Studied species Sperm whale ( Physeter macrocephalus ) Minke whale ( Balaenoptera acutorostrata) Humpback whale ( Megaptera novaeangliae) Northern bottlenose whale Long-finned pilot whale ( Hyperoodon ampullatus ) ( Globicephala melas )
How to measure the behaviour of cetaceans? Methods Non invasive Dtag attachment : use of suction cups. D-tag with suction cups Motor boat Silicon suction cup deployed for tagging operations
Tagging method Hand held Pole Air gun
M a t e r i a l a n d M e t h o d s P r o t o c o l Sonar exposure followed Tagging and post-tagging Baseline by a recovery period Playback experiments Tag recovery Silence Playback (15 min) Playback (15 min) 15-30 min Killer whale sounds Broad band noise Data collection 8m 8m 140-155dB 140-155dB
Results: behavioural changes of sperm whales in response to killer whale sounds playbacks 90% time: performing foraging dives 10% time: Sperm whale resting dives ( Physeter macrocephalus ) 1/ Hydrophones Pressure sensor Acoustic recordings Dive profile D-TAG VHF transmitter Observations of the animal at each surfacing to assess: - Horizontal movements - Social behaviour
1/ Results of the dive profile Curé et al. 2013 ( Scientific Reports (3) : 1579 ) Moyenne sur 5 individus Duration of the dives (min) 40 ns Dive profile of one tagged whale 35 30 Noise KW 25 Duration 20 * 0 15 10 100 5 0 Depth (m) ctrl noise orca ctrl Noise KW 200 300 Max depth of the dives (m) 500 ns 400 400 Interruption of the dive Max depth 300 500 0 1 2 200 Time (h) * 100 Killer whale playbacks induced 0 ctrl noise orca ctrl Noise KW shorter and shallower dives.
Results: behavioural changes of sperm whales in response to killer whale sounds playbacks 90% time: performing foraging dives 10% time: Sperm whale resting dives ( Physeter macrocephalus ) 1/ 2/ Hydrophones Pressure sensor Acoustic recordings Dive profile D-TAG VHF transmitter Observations of the animal at each surfacing to assess: - Horizontal movements - Social behaviour
2/ Results of the acoustic recordings Dive profile +vocalizations of one tagged whale Curé et al. 2013 ( Scientific Reports (3) : 1579 ) Absence d’émission Noise KW Durée Vocalizations 0 produced during 100 foraging dives: Depth (m) 200 300 400 500 0 1 2 Time (h) Frequency (kHz) Clicks Buzz 15 Time (s) 15
2/ Results of the acoustic recordings Mean ± sem, N= 5 tagged whales Number of buzzes per dive Clicking time per dive (%) ns ns 100 8 80 6 * * 60 4 40 2 20 0 0 1 2 3 ctrl ctrl Noise bruit orque KW ctrl Noise KW Clicking activity and number of buzzes were significantly lower during KW playbacks compared to baseline . Curé et al. 2013 ( Scientific Reports (3) : 1579 )
Results: behavioural changes of sperm whales in response to killer whale sounds playbacks 90% time: performing foraging dives 10% time: Sperm whale resting dives ( Physeter macrocephalus ) 1/ 2/ Hydrophones Pressure sensor Acoustic recordings Dive profile D-TAG 3/ VHF transmitter Observations of the animal at each surfacing to assess: - Social behaviour - Horizontal movements
3a/ Results : social behaviour Dive profile of tagged whale sw10_150a At each surfacing phase, we collected the group size. Noise KW
3a/ Results : social behaviour Curé et al. 2013 ( Scientific Reports (3) : 1579 ) Dive profile of tagged whale sw10_150a Range of group size Noise KW Noise
C o n c l u s i o n Model of disturbance in sperm whales: Killer whale playbacks specifically modify cetaceans ’ behaviour. Comparison to reactions to sonar: reactions to KW playbacks and to sonar are concordant. Reactions to sonar are less consistent among inviduals than reactions to K playbacks. Abnormal feeding Change in vocal dive production + + KILLER WHALE PLAYBACKS + + SONAR EXPOSURE _ _ Noise PLAYBACKS The behavioural changes triggered by sonar are similar to a stress induced by predation risk
3S Project partners : Research Fundings : Charlotte Curé’ s post -doc fundings and institutions : D irection G énérale de l’ A rmement Norwegian Animal Research Authority (Permit No. 20607 and 61201). St Andrews Animal Welfare and Ethics Committee (AWEC) . WHOI’s Institutional Animal Care and Use Committee (IACUC).
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