This WAMSI 2 project complements wider research programs which aim to increase our understanding of the distribution, abundance and population connectivity of Australian snubfin (Orcaella heinsohni) and humpback (Sousa sahulenis) dolphins, including the development of new research and monitoring methods.
In this project, we:
(i) collected genetic samples from snubfin and humpback dolphins at selected locations in the Kimberley and assessed the connectivity between these and previously sampled populations elsewhere in north-western Australian waters;
(ii) collected boat-based sightings and photo-identification data to assess the relative abundance of snubfin and humpback dolphins at selected locations in the Kimberley region; and,
(iii) investigated the application of passive acoustic monitoring (PAM) as an effective technique for monitoring these species, including: characterisation of the underwater soundscape of two Kimberley locations; and, the collection of data on the acoustic repertoire and vocalisation rates of snubfin and humpback dolphins.
Our results provide managers and policy-makers with valuable data on the relative importance of several sites within the Kimberley region to snubfin and humpback dolphins, along with an improved understanding of the connectivity of populations and the appropriate geographic scales at which to manage them. We have shown that PAM provides a method of effectively detecting snubfin and humpback dolphins in high-use areas, and have increased the information base from which to further develop PAM towards more quantitative and species-specific monitoring of these dolphins.
Our collaborative approach included training and participation by Yawuru, Bardi-Jawi, Dambimangari and Balanggarra Traditional Owners, and a Marine Park Joint Management team. This has resulted in an improved understanding and capacity of relevant local land and sea managers to collect data on these poorly-understood species within remote areas, and laid the foundation for ongoing research in the Kimberley region.
