Behavioral responses of humpback whales (Megaptera novaeangliae) to whale-watching vessels on the southeastern coast of Australia

Abstract

This study assessed the short‐term responses of humpback whales to whale‐watching vessels during their southward migration along the south coast of New South Wales (NSW), Australia. The behavior of pods was recorded from commercial whale‐watching vessels during tours and compared to pods observed in the absence of vessels from the shore in the same area. While some individuals showed obvious signs of horizontal avoidance, others approached vessels, initiating interactions. Calf pods were more sensitive to the presence of vessels than non‐calf pods. Dive times and the overall percentage of time whales spent submerged were higher in the presence of vessels, but respiration intervals did not differ. Some surface behaviors occurred less often in the presence of vessels. Whales' responses differed according to whether vessels were operating in accordance with regulations or not. Whales were more likely to avoid a vessel moving within the permitted 100 m approach limit than vessels outside the limit. Whales showed some behavioral changes when vessels operated in accordance with whale‐watching regulations, compared with whales in the absence of vessels. Pods that showed no obvious horizontal responses to vessels changed their diving and surface activity when compared with pods in the absence of vessels. Because the long‐term impacts of effects of vessels are unknown, management of the humpback whale‐watching industry should adopt a conservative approach. Improved knowledge of long‐term impacts of multiple exposures to vessels is required to inform management of the effects of whale‐watching.

Distance does matter: close approaches by boats impede feeding and resting behaviour of Indo-Pacific bottlenose dolphins

“…Southern resident killer whales (Orcinus orca) along San Juan Island, USA, spent more time travelling and less time feeding when whale-watching boats were as far as 1000 m away from the pod ). Humpback whales (Megaptera novaeangliae) also exhibited less feeding behaviour when encountered by whale-watching boats within 1000 m along the south-eastern coast of Australia (Stamation et al 2010).…”

“…Cetacean-based tourism is one of these growing potential threats and has resulted in increased exposure of dolphin and whale populations to high levels of boat traffic and disturbance (e.g. Bejder et al 2006b;Stensland and Berggren 2007;Stamation et al 2010).…”

Whale Watching as Ecotourism: How Sustainable is it?

“…Adaptive management should aim at reducing the number of noise events per boat, which can improve the whale watching experience and reduce the impact on male singing behavior. Stamation et al (2010) found that calf pods were more sensitive to the presence of vessels than non-calf pods, and that dive times and the overall percentage of time whales spent submerged were higher in the presence of vessels. The authors caution that since the long-term impacts of the effects of vessels are unknown, management of the humpback whale-watching industry should adopt a conservative approach.…”

Spatial Distribution and Habitat Use Patterns of Humpback Whales in Okinawa, Japan

“…Meanwhile, whale watching tour to see humpback whales had begun in New England and Hawaii in 1975 and is expanding all over the world since then (Hoyt 2001). As the whale watching industry grows, the concern over negative impact on whales being watched also grows (Tilt 1987;Beach and Weinrich 1989;Corkeron 2004;Stamation et al 2010). There are some reports suggesting that the behavioral changes of whales can be induced by close approach of tourist vessels (Williams et al 2002;Lusseau 2003;Scheidat et al 2004).…”

“…These reports also indicate that females with a calf are more sensitive and susceptible to vessel disturbance *To whom correspondence should be addressed. E-mail: n-kobayashi@okichura.jp than whales without a calf (Bauer 1986;Stamation et al 2010). The Large Whale Ship Strike Database shows that approximately 14% of the collisions between ships and whales in the United States of America are associated with whale watching vessels (Jensen and Silber 2003).…”