Kimberley dolphin monitoring
With its beakless rounded snout, this unusual cetacean was, until 2005, thought to be the Irrawaddy river dolphin, a species once prevalent in South-East Asia. DNA and morphology reassessment however, revealed it be a separate species (Orcaella heinsohni) unique to northern Australia. This was an exciting discovery for modern day science, as it is extremely rare for a new species of mammal to be described.
Even more exciting is the discovery that Roebuck Bay has one of the largest known populations across its range. Dr Alex Brown (Murdoch University Cetacean Unit) photographically identified around 130 snubfin dolphins in Roebuck Bay, from individual markings on their dorsal fins. Whilst the dominant species in the bay are snubfins, smaller mixed populations of Australian humpack dolphins and Indo-Pacific bottlenose dolphins can be seen too.
Threats
A RECENT EXPANSION in human activities targeting the Kimberley’s rich resources, remoteness and grandeur has resulted in intrusions into dolphin habitat with commercial fishing; coastal boat based ecotourism; recreational line and net fishing; illegal Indonesian fishing; oil and gas developments and extensive marine (pearl) farming.
Identifying habitat and status
IN A JOINT program with WWF-Australia and the Kimberley Land Council, the Kimberley Coast Inshore Dolphin Project aims to combine scientific research and real community participation to identify important habitat and determine the conservation status of Orcaella using marine surveys, land based tracking and a community sighting network.
The program involves intensive research, training in marine wildlife monitoring for Indigenous rangers and knowledge sharing across Kimberley communities.
IN ADDITION, we are gathering the same information for the two other nearshore dolphin species in the Kimberley: the Indo-Pacific Humpback Dolphin and the Bottlenose Dolphin and other marine wildlife species. This information will help to raise awareness of the nature and importance of protecting Kimberley ecosystems for the future.
Engaging the community
Kimberley near shore dolphin identification card. © 2009 Deborah Thiele. Press to enlarge.
A COMMUNITY sighting network has been operating since 2005 around Broome. Photographs and records of sightings sent in from members of the community have been critical in tracking individual dolphins in Roebuck Bay. For example, photographs sent in by John and Jacqui Rushford have been combined with the research team photo identification catalogue allowing us to track one individual snubfin dolphin over a four year period. This sort of information is very important in building up a picture of how the dolphins use the bay, where they feed, their health, the incidence of injuries and the social dynamics and movements of these animals.
Anyone with a pen and paper and a camera can contribute in this way. So if you are out and about in coastal or estuarine waters from Cape Londonderry to Broome or in the Cambridge Gulf area, we would like you to participate in the sighting network.
Supported by:
Volunteering opportunities…