A team of researchers from Macquarie University and Taronga Zoo has just released the results of a study into the effects of whale watching on the behavior of migrating humpback whales.
The two-year study of humpback whales passing the Sydney area during their northern migration found that in the presence of vessels, the whales were more likely to remain on or around the surface than when no vessels were around.
The study indicates that northerly migrating whales off Sydney are more likely to remain on the surface breathing when vessels are around than they are to take some form of avoidance, says researcher Maryrose Gulesserian from Macquarie University.
The largest of the Southern Hemisphere humpback whale stock (E1), the population uses the east coast of Australia as a migratory corridor to travel between feeding grounds in the Southern Ocean and breeding grounds in northeast Queensland and the south-west Pacific Ocean.
Having been decimated in numbers due to whaling during the mid 20th century, the population is now recovering at close to the maximum rate of growth. The increasing abundance of whales passing within sight of land has seen a growing whale-watching industry over the past decade. In 2008 alone, over 25,000 people boarded dedicated vessels in Sydney for the purpose of whale watching
The results of the study are positive; as with the growth in the whale-watching industry around Sydney, concerns have been raised as to the impact it is having on the migratory behaviour of the whales.
From this study it appears that for this population at least, adult humpback whales are relatively robust to disturbance by whale watching, says Gulesserian.
Explore further: Sexual selection isn't the last word on bird plumage, study shows