title: Atypical residency of short-beaked common dolphins (Delphinus delphis) to a shallow, urbanized embayment in south-eastern Australia.
abstract: Short-beaked common dolphins (Delphinus delphis) are typically considered highly mobile, offshore delphinids. This study assessed the residency of a small community of short-beaked common dolphins in the shallow, urbanized Port Phillip Bay, south-eastern Australia. The ability to identify common dolphins by their dorsal fin markings and coloration using photo-identification was also investigated. Systematic and non-systematic boat surveys were undertaken between 2007 and 2014. Results showed that 13 adult common dolphins and their offspring inhabit Port Phillip Bay, of which 10 adults exhibit residency to the bay. The majority of these adults are reproductively active females, suggesting that female philopatry may occur in the community. Systematic surveys conducted between 2012 and 2014 revealed that the dolphins were found in a median water depth of 16 m and median distance of 2.2 km from the coast. The shallow, urbanized habitat of this resident common dolphin community is atypical for this species. As a result, these common dolphins face threats usually associated with inshore bottlenose dolphin communities. We suggest that the Port Phillip Bay common dolphin community is considered and managed separate to those outside the embayment and offshore to ensure the community's long-term viability and residency in the bay.
authors.affiliation: The Dolphin Research Institute (DRI), PO Box 77, Hastings, Victoria 3915, Australia; Centre of Marine Science and Technology (CMST), Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia.
authors.forename: Suzanne
authors.identifier: 0000-0002-6053-9062
authors.initials: S
authors.lastname: Mason
authors.affiliation: Centre of Marine Science and Technology (CMST) , Curtin University , GPO Box U1987, Perth, Western Australia 6845 , Australia.
authors.forename: Chandra
authors.initials: C
authors.lastname: Salgado Kent
authors.affiliation: The Dolphin Research Institute (DRI) , PO Box 77, Hastings, Victoria 3915 , Australia.
authors.forename: David
authors.initials: D
authors.lastname: Donnelly
authors.affiliation: The Dolphin Research Institute (DRI) , PO Box 77, Hastings, Victoria 3915 , Australia.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Weir
authors.affiliation: Department of Biological Sciences , Macquarie University , Sydney, New South Wales 2109 , Australia.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Bilgmann
keywords: female philopatry; inshore community; residency