Can swimming with whales in Tonga be sustainable?

• Main Authors: Kessler, Megan, Harcourt, Robert, Heller, Gabien
• Format: Conference Object
• Language: English
• Published: 2012
• Subjects: /dk/atira/pure/mqoutputs/27; E2 - Non-refereed Conference Publication - paper published in full; Tonga; Humpback Whale; Megaptera novaeangliae
• Online Access: https://researchers.mq.edu.au/en/publications/0637b377-4f6a-4e9a-b52f-b085772756e3; https://archive.iwc.int/pages/search.php?search=!collection186&bc_from=themes

Humpback whales (Megaptera novaeangliae) using Tongan waters are part of the endangered Oceania population. Despite their slow recovery rate and small population size, this population supports a swim-with whale industry that generates approximately 15% of all foreign income in the Tongan economy. However, the sustainability of swimming with whales in Tonga has been questioned due to its potential disturbance of breeding mothers and calves. This study investigated whether whales responded differently when swimmers and boats were with whales compared to when boats were present without swimmers, and assessed the influence of different swimmer behaviour. Humpback whale behaviour was recorded from a commercial whale watching vessel and from dedicated research vessels. In the swim treatments, up to five swimmers approached whales in one of three ways: 1/ quietly slipping into the water and approaching at the surface making minimal noise; 2/ approaching the whales at the surface making loud, vigorous splashes; and 3/ approaching the whales with surface swimming and undertaking subsurface diving. In the no swimming control, whale behaviour was recorded when the boat approached the whales but no swimmers entered the water. Time until whales moved away was recorded. 51 trials were conducted, spread across treatments and boats. Preliminary results show that a quiet swim approach does not create a significantly different impact on the animals’ behaviour compared to watching from a boat. A louder approach causes a significant change in behaviour. Operators’ selection of how the swimmers approach the whales is crucial in ensuring the sustainability of the industry.