Dolphin Research

Did you know that there are numerous studies on the dolphins that live in the rivers and in WA coastal waters? Check out some of the following papers below:

Integrating systematic and citizen science surveys for monitoring and management of near-threatened Indo-Pacific bottlenose dolphins in the Swan Canning Riverpark, Western Australia  (Prepared by Chandra Salgado Kent1 and Delphine Chabanne21 School of Science, Edith Cowan University, Joondalup, WA 6027 2 Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch WA 6150

The aim of this study was to undertake a comparative analysis of spatial and temporal patterns of Indo-Pacific bottlenose dolphin (Tursiops aduncus) sighted in the Swan Canning Riverpark (Western Australia) collected from two survey modes (citizen science and scientific vessel surveys); and thereby inform management directly and plan for ongoing future monitoring.

Niche partitioning among social clusters of a resident estuarine apex predator (Prepared by Dr Krista Nicholson)

This study identified intra-population resource partitioning according to social structure in a resident estuarine dolphin population. The heterogeneity in space use and diet among social clusters may result in individuals being susceptible to different pressures and threats. The dolphins’ foraging behavior and trophic interactions identified them as an apex predator in the Peel-Harvey Estuary, with their collective minimum annual food intake (~ 200,000 kg) exceeding the annual fish biomass removed by commercial fishers. As top predators in the system, dolphins may suppress prey populations through consumption and as agents of intimidation by changing prey distribution and behavior. This study provides scientific basis for recognizing dolphins as an important component of the Peel-Harvey Estuary ecosystem.

Minimum Age Estimation of Swan Riverpark Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) using teeth structure as a Determinant.

Data on age at mortality is limited for mammals in general, and more so for marine mammals because of their difficult accessibility. For mammals studied, minimum age at mortality data from naturally deceased animals has been obtained successfully through the analysis of tooth structure. The dentine and cementum layers provide an indication of age because alternating opaque and translucent layers of tissue are laid down annually.

Regional assessment of the conservation status of Snubfin Dolphins (Orcaella heinsohni) in the Kimberley Region

Implementing conservation measures for data-limited species is a fundamental challenge for wildlife managers and policy-makers, and proves difficult for cryptic marine animals occurring in naturally low numbers across remote seascapes. There is currently scant information on the abundance and habitat preferences of Australian snubfin dolphins (Orcaella heinsohni) throughout much of their geographical range, and especially within the Kimberley region of northern Western Australia. Such knowledge gaps curtail rigorous threat assessments on both local and regional scales. To address this and assist future conservation listings, we built the first comprehensive catalogue of snubfin dolphin sightings for the Kimberley. We used these data to estimate the species’ extent of occurrence (EOO) and area of occupancy (AOO) along the region’s 7,000 km coastline.

Inconsistency between socio-spatial and genetic structure in a coastal dolphin poplulation

Back in 2013-2015, Dr Delphine Chabanne collected some skin/blubber sample from dolphins. From those samples, Delphine extracted the DNA which was then used to identify the sex of our dolphins and mostly specifically to this recently published study DNA was used to check whether dolphins were genetically connected based on the level of similarity and difference we can find between individual’s DNA.

The results supported that our Swan Canning Riverpark dolphins are genetically connected with dolphins from Cockburn Sound and from other adjacent waters.

Whistle Characteristics of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) in the Fremantle Inner Harbour, Western Australia 
Centre for Marine Science and technology, Curtin University
Overview: Bottlenose dolphins use whistles to communicate with each other. We recorded 477 whistles of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Fremantle Inner Harbour, Western Australia, on nine occasions over a six-week period during May/June 2013. 

Cetacean Morbillivirus in Coastal Indo-Pacific Bottlenose Dolphins, Western Australia.

Overview: Cetacean morbillivirus (CeMV) has caused several epizootics in multiple species of cetaceans globally and is an emerging disease among cetaceans in Australia. We detected CeMV in 2 stranded coastal Indo-Pacific bottlenose dolphins (Tursiops aduncus) in Western Australia. Preliminary phylogenetic data suggest that this virus variant is divergent from known strains. (Stephens et al_2014)

Identifying the Relevant Local Population for Environmental Impact Assessments of Mobile Marine Fauna

Overview: Environmental impact assessments must be addressed at a scale that reflects the biological organization for the species affected. It can be challenging to identify the relevant local wildlife population for impact assessment for those species that are continuously distributed and highly mobile. Here, we document the existence of local communities of Indo-Pacific bottlenose dolphins (Tursiops aduncus) inhabiting coastal and estuarine waters of Perth, Western Australia, where major coastal developments have been undertaken or are proposed. Poster here.

Applying the multistate capture–recapture robust design to characterize metapopulation structure  

Overview: To date, bottlenose dolphin studies using mark–recapture approach have focussed on investigating single subpopulations. Here, in a heterogeneous coastal–estuarine environment, we demonstrated that spatially structured bottlenose dolphin subpopulations contained distinct suites of individuals and differed in size, demographics and connectivity. Such insights into the dynamics of a metapopulation can assist in localā€scale species conservation. Summary presentation here.

 

Annual Reports

The data collected by volunteers each year is interpreted by scientists at Curtin and Murdoch universities. These annual reports serve as a window into the lives of the dolphins and calves living in and visiting the Swan and Canning rivers. 
To all of the dedicated Dolphin Watchers, please keep up the good work. 

Dolphin Watch Annual Report 2015 -16

Dolphin Watch Annual Report 2014 -15

Dolphin Watch Annual Report 2013 -14

Dolphin Watch Annual Report 2012 -13

Dolphin Watch Annual Report 2011 -12

Dolphin Watch Annual Report 2010- 11

Dolphin Watch Annual Report 2009 -10