Dwarf minke whales are an undescribed subspecies of minke whale that occur throughout the southern hemisphere and were first recognised in the Great Barrier Reef in the 1980s1. As the name would imply, dwarf minke whales are smaller than other forms of minke whale (less than 8m), and are recognizable by their distinct colour patterns which include swirls and blazes not present in other minke whales and a distinct white shoulder patch2.
The Great Barrier Reef off the northeast coast of Australia has been a popular diving and snorkeling destination for many decades. It was declared a World Heritage Area in 1981, and in 2016 it attracted 2.4 million tourists3. In the 1990s, as divers and snorkellers began frequenting the outer shelf Ribbon Reefs north of Port Douglas on live-aboard dive vessels during the austral winter, they began to experience close encounters dwarf minke whales. From the mid-1990s onward dive tour operators began to advertise ‘swim-with-minke whales’ trips. Although swimming with whales in Australia was generally prohibited, a limited swim-with whale program was officially recognized, endorsed and permitted by the Great Barrier Reef Marine Park Authority in 2003. A cap was set on the number of operators (maximum of 9 permits) that would be able to offer swim-with-minke whales tours: all of which have been based in the Cairns and Port Douglas region.
Permits are issued under the condition that all vessels interacting with dwarf minke whales comply with a Code of Practice, and contribute to standardized monitoring of all their whale encounters. The operators are encouraged to share additional data from their encounters (underwater photos, etc) with researchers conducting long-term studies of the whale’s population biology and behaviour. More than 20 years of close collaboration between the dive operators, Reef managers, and scientists from the Minke Whale Project at James Cook University has resulted in an improved understanding of the whales’ population, behavior and migration, and has helped to refine management policy to ensure that the swim-with activities are managed sustainably.
An unusual aspect of the minke whale swims, is that the majority of encounters are initiated by the whales themselves, which often approach a stationary vessel or swimmers/divers who are already in the water4. Passenger-whale interactions tend to be extensive, lasting an average of more than two hours5. To ensure the safety of snorkelers during in-water encounters, and to prevent whales being chased or harassed, it is required for the operators to put out surface ropes for swimmers to hold onto.4
While little is known about the whales’ population and life history outside of their brief aggregation each winter in the Great Barrier Reef, photo-identification studies have allowed researchers to recognize individual whales that are re-sighted within and across seasons6,7. Analyses of data on the distribution, frequency, and duration of encounters have shown that whales are reliably found in a limited number of ‘hotspots’ in the Ribbon Reefs, and individual whales have been observed returning to these same places year after year. Such hotspots have been targeted with increasing frequency by permitted live-aboard vessels, resulting in highly reliable interactions each June-July season.
Research conducted in the late 90’s contributed to the drafting of the first code of practice for swimming with dwarf minke whales 1999. This code was voluntarily adopted by operators in 2002, and was recognised by the Great Barrier Marine Park Authority when they issued the first permits to manage swim-with-whale tourism in the Marine Park in 2003. Since that time, permits have been a legal requirement to conduct swims, and the number of operators remains low to reduce the potential for cumulative impacts of human interactions on the whales.
The Code of Practice for minke whale encounters is based on research and observations of hundreds of interactions with the whales, and is designed to be adaptive, allowing it to be updated from time to time as new information or management issues emerge. The current code includes the following stipulations:
There are concerns in the research and conservation community about in-water encounters with whales. Whales are large and powerful animals, capable of causing injury to humans with the sweep of a tail. There are also concerns for the well-being of the whales, particularly for those individual dwarf minke whales who return to the same site every year and may be the focus of repeated and lengthy encounters with humans during their stay8. Studies have documented the potential long-term impacts of tourism-induced changes to whale or dolphin behaviour9-12, and these potential impacts need to be considered for minke whales on the Great Barrier Reef as well. The Minke Whale Project has an ongoing role in monitoring the sustainability of the swim-with-whales activity, and many of the rules and recommendations in the Code of Practice and other related materials (e.g. interpretive materials distributed to each permitted boat each year, annual reports to government agencies) have been based on research findings and designed with the well-being of the whales as the first priority.
This case study presents a number of strengths and challenges for consideration:
Strengths:
Challenges:
For more information about swimming with minke whales in the Great Barrier Reef please consult: