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Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Swan-Canning Estuary (Perth, WA): ecology, status, and future research.

Chabanne, D., Finn, H., Salgado, C., Nam Lo, H., Moiler, K. and Bejder, L. (2011) Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Swan-Canning Estuary (Perth, WA): ecology, status, and future research. In: 48th Annual Conference of the Australian Marine Science Association, 3 - 7 July, Fremantle, Western Australia.

Abstract

From October 2001 to June 2003 we photo-identified 35 Indo-Pacific bottlenose dolphins (Tursiops aduncus) within the Swan-Canning Estuary in Perth, Western Australia (n = 223 survey days). Analyses of occupancy, ranging, and association patterns identified two main groupings: (a) transient - dolphins sighted less than six times generally near the estuary mouth (n = 13, 37.1%) and (b) resident - dolphins consistently observed (n > 23 sightings) throughout the estuary and in association with each other (n = 18, 51.4%). The current status of dolphins in the estuary is not known. Low-level monitoring (n = 17 survey days) in 2008-9 re-sighted nine (50%) of the 2001-3 residents, while the carcasses of two (11.1%) were recovered in 2006 and 2009, one (5.6%) was presumed dead in 2002, and the status of the other six (33.3%) is not known. The deaths of six dolphins within the estuary in 2009 raised concerns about the long-term conservation of dolphins in the estuary and emphasised the need for new research. As part of a broader study of dolphins in the metropolitan waters of Perth, from June 2011 we will be conducting systematic boat-based surveys using belt transects coupled with individual focal follows within the estuary and adjacent coastal waters. This research has several objectives: (1) estimate dolphin abundance across the study area using photo-identification and mark-recapture methods; (2) determine residency and ranging patterns for individuals in order to better understand site fidelity and population structure; (3) determine habitat use patterns through habitat modelling; and (4) collect behavioural, environmental, and epidemiological data related to interactions with human activities and dolphin health (e.g. entanglements, epidermal diseases).

Publication Type: Conference Item
Murdoch Affiliation: Centre for Fish and Fisheries Research
Conference Website: https://www.amsa.asn.au/conference/amsa2011_freman...
URI: http://researchrepository.murdoch.edu.au/id/eprint/6681
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