Behaviour of dwarf minke whales (Balaenoptera acutorostrata subsp.) associated with a swim-with industry in the northern Great Barrier Reef

• Main Author: Mangott, Arnold H.
• Format: Thesis
• Language: unknown
• Published: 2010
• Subjects: Austral; Balaenoptera acutorostrata; minke whale
• Online Access: https://researchonline.jcu.edu.au/19001/6/JCU_19001_Mangott_2010_Thesis.pdf

A diffuse aggregation of dwarf minke whales occurs in the northern Great Barrier Reef World Heritage Area during the austral winter months. This area coincides with a region heavily used by a large dive and snorkel tourism industry. Over the last two decades a small part of this industry has developed into a swim-with dwarf minke whale industry that has been limited via a permit scheme since 2003. Very little was understood about the whales' behaviour or the response of the whales to the vessels and swimmers. In order to address this knowledge gap, I designed this study with two major aims: (1) to provide detailed insights into the behaviour of dwarf minke whales around tourism vessels and swimmers, and (2) to establish recommendations for the tourism industry and management agencies to provide for discussions on future management and to contribute to the sustainability of this industry. During my research (2006-2008), I described over 30 distinctive dwarf minke behaviours and provided evidence for the presence of behaviours with potential social and investigative functions. Behaviours with likely social attributes such as belly presentations and bubble releases, were significantly influenced by a large group size (>6 animals), while investigatory behaviours such as close and very close approaches, motorboating, and headrises were positively influenced by the presence of resighted animals. Dwarf minke whales are a predominantly solitary oceanic species. When they form social groups, behaviours which convey information among conspecifics via visual communication (e.g. presenting the white belly or releasing bubbles) may be particularly important. The presence of several investigative behaviours during interactions with vessels and swimmers highlights the inquisitive nature of these whales and suggests that such behaviours are an important part of their ecology (i.e. finding mates, food or avoiding predators). I also investigated potential agonistic and disturbance displays of dwarf minke whales and provided an ...