MORE evidence is emerging that ecotourism is not as benign as it first appeared. Killer whales are calling for longer in a bid to overcome the cacophony produced by tourist boats.
Sonar use during military operations has been linked to mass strandings of beaked whales and also seems to prompt changes in humpback whale calling behaviour. What is more, dolphins spend longer at the surface and rest less when tourist boats are nearby (Â鶹´«Ã½, 6 March 2004, p 7).
Now a team led by Rus Hoelzel at the University of Durham, UK, has shown that human activities are…
