Tourism 'detrimental' to whales in Tonga

Tourists swimming with whales in northern Tonga are disrupting the natural behaviour of humpback whales who travel there to give birth and bond with their calves, new research shows

Some 20 commercial operators take thousands of tourists to swim with whales in the Vava'u island group, one of the most important breeding grounds for Oceania humpback whales, an Auckland University of Technology study said.  

Humpbacks spend the months of July to October in Tonga to give birth before travelling back to Antarctica for the summer. 

Study findings suggest that tourism activities are disturbing mother-calf pairs, the focus of nearly 80 per cent of tours. 

Drone footage has shown that mother whales dive deeper to avoid tour boats and are separated from their newborn calves more often when tours are underway, according to the research, published in the scientific journal PLOSOne. 

Regulations on swimming with whales in Tonga are not well enforced, with 38.4 per cent of tours contravening "whale resting times" (the time between each interaction with tour boats), the study found. 

Study authors said the findings highlight the risks of swim-with-whales tours, which have grown in popularity over the past 20 years. 

"The behavioural responses documented in this study underlie the risk of detrimental effects on this population of whales targeted by swim-with-whale tourism.

"The rapid growth of swim-with-whales industry experienced by Vava'u over a short period of time and the tour operator focus on mother-calf pairs is concerning, especially in the light of the poor compliance with regulations and the lack of enforcement of formal regulations...

"Overall, our findings reinforce the urge for a more cautious and effective approach to the management of swimming activities with humpback whales, both for Tongan authorities and other governments willing to permit these activities."

The study's authors have recommended the Tongan Ministry of Tourism reduce the number of licensed swim-with-whales vessels, introduce a "break time" in the middle of the day when tours are not allowed, and work on improving compliance with regulations.