Commercial Swim Programs With Dwarf Minke Whales On The Northern Great Barrier Reef, Australia: Some Characteristics Of The Encounters With Management Implications

Abstract

Commercial swim programs with the dwarf minke whale Balaenoptera ?acutorostrata occur seasonally (primarily June - July) within the Cairns and Far Northern sections of the Great Barrier Reef (GBR) Marine Park. Observations of whale-swimmer interactions over five seasons indicate that initiation and maintenance of contact with vessel and swimmers is largely voluntary and thus the swim programs can comply with the general principle that the whales control the initiation and nature of interactions. Preliminary data on within-season (13 whales in 1999) and between year (four whales from 1999 in 2000, 2001) re-sightings within the study area suggest that any impacts from swim programs may affect a particular subset of the population. The extent of possible cumulative effects can be assessed by continuation of the existing photo and video-ID program. No signs of aggression have been documented but some behaviour (bubble blasts, jaw gape) could be considered as threat display. More detailed analysis of behaviour is necessary to monitor such behaviour. A risk analysis is given for aspects of the interactions, with suggested research to monitor such risks.