DOLPHINS in north western Australia are at risk from rapid coastal development says a new study.
The Australian Snubfin dolphin (Orcella heinsohni), Indo Pacific Humpback dolphin (Sousa chinensis) and Indo Pacific Bottlenose dolphin (Tursiops aduncus) inhabit nearshore areas that are undergoing rapid and extensive coastal development. The effects of such development on their populations is unclear.
Lead author, Simon Allen from Murdoch University says “there is a lack of baseline data on these dolphins, to base assessments of their vulnerability to impact from human activity.”
The study, the first published account of dolphin species in north western Australia, surveyed seven sites using photo-identification, biopsies and sightings data.
Results show that Humpback and Bottlenose dolphins occur adjacent to all urban centres, and that the range of the Snubfin dolphin extends considerably further south than previously reported.
The study further identifies contradictions in the James Price Point Environmental Impact Assessment process caused by lack of data on these species and their current conservation listings.
“Current listings require updating to better reflect national and international status,” says Mr Allen.
Internationally, Snubfin and Humpback dolphins are listed as “Near threatened” while the Bottlenose dolphin is listed as “Data Deficient”, although classifications recognise the paucity of data available for all species.
The Australian Environmental Protection and Biodiversity Conservation Act 1999 lists them as “Non Threatened Migratory Species”.
WA's Department of Environment and Conservation does not list any inshore dolphin species as threatened or in need of special protection.
This may change says Dr Kelly Waples of DEC, “Commonwealth has funded work to develop a Coordinated Research Strategy to fill information gaps and allow for an assessment of these species’ conservation status”.
There has been very little research on dolphins species in the area prior to this study. Mr Allen says those that have been conducted have been mainly by the proponents of the developments and their consultants.
Data is not generally made available to scientists or management agencies and is not subject to peer review, says Mr Allen.
“There is a conflict of interest in an environmental consultancy accepting funding from the proponents and not having any checks and balances in terms of scientific rigour of their assessments of impacts.”
Coastal developments can cause changes and destruction to vital dolphin habitat says Mr Allen.
“While developments have the potential to influence dolphin populations, without baseline data it is impossible to determine if impacts are manageable.”
The Australian Snubfin dolphin is endemic to northern Australia and there is very little information on the species, while recent evidence suggests that the Humpback dolphin is a separate species from those found in south-east Asia.
The study ‘Tropical inshore dolphins of north-western Australia: Unknown populations in a rapidly changing region' was published in Pacific Conservation Biology.