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Long-term study looks at threats to dolphin population


Brigid Veale
17 June 2015

A new season of research, part of the longest ongoing study of the Australian snubfin dolphin and the Australian humpback dolphin, is getting under way in Central Queensland.

The Capricorn Cetaceans Project (CCP) has been looking at the long-term conservation and management of inshore dolphins in Central Queensland since 2006.

The research has shown that the two species are particularly vulnerable to human and natural threatening processes, including habitat degradation, injury or mortality caused by gillnetting and vessel strike.

The project is led by Dr Daniele Cagnazzi, a postdoctoral research fellow with Southern Cross University’s Marine Ecology Research Centre.

Dr Cagnazzi’s research includes the collection of photographs to estimate population size as well as skin samples to determine the genetic make-up of the different dolphin populations. Skin samples have been also used to investigate the level of contaminants accumulated by dolphins through their diet. The samples are taken using a biopsy system specially designed for inshore dolphins.

“We have collected 155 humpback and 85 snubfin dolphin samples from the Central Queensland coast as well as from Moreton Bay, Great Sandy Strait, Whitsundays and Townsville,” Dr Cagnazzi said.

These genetic markers, obtained through the skin samples, are used to distinguish individuals.

“As a mother and child share the same DNA, dolphins from the same population will have a more similar ‘genetic fingerprint’ than dolphins from different populations,” he said.

“In both species, we found the levels of genetic diversity were remarkably low which makes them more vulnerable to anthropogenic threatening processes, including habitat degradation, fishery bycatch and vessel strike.

“We also found very small migration rates between almost all regions. This indicates that humpback and snubfin dolphins from Central Queensland form distinct groups, or what we call ‘Management Units (MUs)’.

“Available population estimates suggest that these Central Queensland management units support less than 200 individuals of each species.
“We need to ensure local conservation policies are put in place to ensure the long-term survival of these local populations.”

The project is funded by Gladstone Ports Corporation, through the Ecosystem Research and Monitoring Program and the Fitzroy Basin Association Inc., through funding from the Australian Government, the Australian Marine Mammal Centre and Southern Cross University.

More information on the project can be viewed on the project webpage and project Facebook page (search for Capricorn Cetaceans Project on Facebook).

More detailed information sessions on the Capricorn Cetaceans Project are being held for any interested members of the public.

Rockhampton Flow Visitor Centre (80 East Street, Rockhampton 4700): Wednesday July 1 at 2pm.

Gladstone City Library (39 Goondoon St, Gladstone 4680): Thursday July 2 at 4.30pm.

See the website for dates and times for Yeppoon.

Photo: An Australian humpback dolphin strand-feeding. Photo by Rebecca Tite, a member of the Capricorn Cetaceans Project team.