@inproceedings{fdi:010081984,
  title = {{D}o whales really care about conventional fisheries acoustics ? [poster]},
  author = {{N}øttestad, {L}. and {B}rehmer, {P}atrice and {J}osse, {E}rwan and {D}oksaeter, {L}. and {P}avan, {G}. and {S}ancho, {G}. and {L}ebourges-{D}haussy, {A}nne and {G}eorgakarakos, {S}. and {A}umeeruddy, {R}. and {D}alen, {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}ntroduction : {A}coustic  monitoring  is  considered  essential  for  the  modern  exploration  and  understanding  of  marine  communities  and  ecosystems.  {N}evertheless, underwater  noise  pollution  may  have  potentially  negative  effects,  particularly  on  marine  mammal  and  fish  physiology  and  behaviour.  {T}his  study  aim  to  quantify how offshore  whales and dolphins react on conventional fisheries acoustics from both a stationary and moving research vessel. {M}aterial and {M}ethods : {A}n acoustic monitoring methodology was applied with conventional fisheries acoustic instrumentation. {A} three-frequency echosounder (38, 70 and 120 k{H}z) and  an omnidirectional  multibeam sonar  (24  k{H}z)  were  connected  to  artificial  drifting  {F}ish  {A}ggregating  {D}evices  ({FAD}s)  during  an  international  scientific  cruise  ({F}ebruary  2004)  in  the  western  {I}ndian  {O}cean.  {A}  moving  vessel  equipped  with  multi-frequency echosounders (18,  38,  70,  120  and  200  k{H}z)  andmultibeam (20-30, 110-120 k{H}z) sonars was also used during an ecosystem survey in the {N}orwegian {S}ea. {D}igital filming and ping-to-ping sonar tracking of animals were used to study marine mammal behaviour and possible reaction patterns to emitted sound from hydro-acoustic instrumentation. {R}esults : {W}hen using conventional fisheries acoustics in the {I}ndian {O}cean, a group of sei whale approached a stationary vessel, providing some evidence that the acoustic signals did not cause a measurable avoidance response by the whales. {S}imilarly, large whales (fin, humpback and sperm whales), and dolphins (pilot and killer whales) did not show measurable behavioural responses and avoidance reactions towards a moving vessel. {G}roups of whales and dolphins were actively feeding on herring, mackerel and krill for 10-40 minutes simultaneously as the vessel was within 50-800 meters distance at different speed (2-12 knots). {O}ur results suggest that many marine mammals in open oceans do not actively avoid stationary or moving vessels applying fisheries acoustics. {F}urther studies are needed to find operational hydro-acoustic thresholds (intensity, time and frequency), according to species and area specific hearing sensibility and reaction patterns, and to enlighten the physical/physiological impacts of human induced acoustic stimuli on marine mammals. {W}e stress the importance of defining ?{U}nderwater {N}oise {T}olerance {T}hresholds?, as other anthropogenic sounds may strongly influence marine mammal behaviour and physiology.},
  keywords = {{OCEAN} {INDIEN} ; {MER} {DE} {NORVEGE}},
  numero = {},
  pages = {1  multigr.},
  booktitle = {},
  year = {2007},
  URL = {https://www.documentation.ird.fr/hor/fdi:010081984},
}