Abstract
A diffuse aggregation of dwarf minke whales occurs in the northern Great Barrier Reef World Heritage Area (GBRWHA) during the austral winter months. The whales voluntarily approach dive tourism vessels and their passengers and maintain contact for prolonged periods (mean ± SE = 3.9 ± 0.57 h). We report on 521 industry-wide dwarf minke whale encounters (2006–2007) and provide detailed analyses of 20 encounters in 2006 and 18 in 2007 from the vessel Undersea Explorer. The whales surfaced significantly more often within a 60 m radius of the vessel than expected, and aggregated especially around swimmers. The inquisitiveness of the whales creates several management issues including compliance difficulties for non-swim-with whales endorsed operations. The whales' close and prolonged association with vessels and swimmers indicates a strong attraction of these animals to the stimulus and raises concerns about the wellbeing of the whales and the swimming participants. Preventing these encounters would be difficult without banning dive tourism in the GBRWHA for several months. Several management strategies are highlighted and broader education is recommended to reduce the potential of adverse impacts on the whales.