Oceans of noise - Whale and Dolphin Conservation Society

Species type: Boto, Inia geoffrensisTucuxi, Sotalia fluviatilisLocation: Amazon river, Peru• Boto, Inia geoffrensis, and Tucuxi, Sotalia fluviatilis, demonstrated avoidance reactions andwere temporarily displaced by boats.Ref: Leatherwood et al. 1991.Species type: Black dolphin, Cephalorhynchus eutropicaLocation: Chile• Chilean Black dolphins, Cephalorhynchus eutropica, tended to avoid boat traffic. However,on some occasions animals would approach vessels.Ref: Crovetto and Medina 1991.Species type: Narwhal, Monodon monocerosLocation: Arctic• Narwhals, reacting to the noise produced by a large vessel and an icebreaker ship, ceasedvocalising.• Reactions were, however, temporary and normal behaviour resumed even though receivedbroad-band noise levels were as high as 120 dB re 1µPa.• However, avoidance reactions were recorded by some animals and these could be displacedover considerable distances.Ref: Findley et al. 1990.Species type: Squid-eating cetaceansLocation: East Coast, USA.• Densities of squid-eating cetaceans were reduced in the Northwest Atlantic within severalkilometres of shipping vessels.Ref: Sorensen et al. 1984.Species type:Location:Striped dolphin, Stenella coeuruleoalbaSpotted dolphin: Stenella attenuataTropical Pacific Ocean• Striped and spotted dolphins approached by a research vessel tried to evade, increased theirswimming speed and the group became more densely packed, when the vessel came within200m147