Territory Stories

The Darwin Dolphin Monitoring Program : Abundance, Apparent Survival, Movements and Habitat Use of Humpback, Bottlenose and Snubfin Dolphins in the Darwin Area.



The Darwin Dolphin Monitoring Program : Abundance, Apparent Survival, Movements and Habitat Use of Humpback, Bottlenose and Snubfin Dolphins in the Darwin Area.


Brooks, Lyndon; Pollock, Kenneth; Northern Territory. Department of Land Resource Management


E-Publications; E-Books; PublicationNT




This report presents the results of a coastal dolphin monitoring program for the Ichthys LNG Project (the Project) in Darwin Harbour. The monitoring program comprised a capture-recapture study and a spatial habitat use study on humpback, bottlenose and snubfin dolphins in Darwin Harbour and two adjacent sites, Bynoe Harbour to the west and Shoal Bay to the east (the sample area). Data were collected over a period of three and a half years (October 2011 to April 2015) in a systematic and intensive sampling program consisting of eight twice-yearly sampling sessions (dry and wet season samples), each of approximately three weeks duration (primary samples). The capture-recapture study, based on photographic identification of individuals, yielded estimates of abundance, apparent survival and movements by site and over time. The spatial habitat use study, based on group detections, yielded estimates of variation in use of the sample area in terms of locations and over time.


Made available via the Publications (Legal Deposit) Act 2004 (NT)




Dolphins -- Northern Territory -- Ecology; Biodiversity conservation -- Northern Territory

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Northern Territory Government

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iv, 51 pages : colour map ; 30 cm.

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Attribution International 4.0 (CC BY 4.0)

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Northern Territory Government



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The Darwin Dolphin Monitoring Program 3 GENERAL INTRODUCTION CONTEXT AND PURPOSE A monitoring program for coastal dolphins was required for the Ichthys LNG Project (the Project) in Darwin Harbour as part of the environmental approvals under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and the Northern Territory Environmental Assessment Act 1982. The monitoring program included pre- and post- construction phase monitoring. Dredging for a safe shipping channel and gas export pipeline, and marine pile driving for the product loading jetty and module offloading facility in Darwin Harbour East Arm, are considered to be the extent of the construction phase for this monitoring program. The stated aim of the program was: To detect change, beyond natural spatial and temporal variation, in coastal dolphin abundance and distribution during near shore Project construction activities in Darwin Harbour, including pre- and post- construction phase monitoring. Three species of coastal dolphin inhabit the Darwin Harbour region (extending from Gunn Point to Bynoe Harbour): Australian humpback (Sousa sahulensis; hereafter referred to as humpback, see Mendez et al. 2013 for recent taxonomic results), bottlenose (Tursiops sp., hereafter referred to as bottlenose) and Australian snubfin (Orcaella heinsohni, hereafter referred to as snubfin) dolphins. All three species are listed as Marine and Migratory species (and hence are matters of National Environmental Significance) under the EPBC Act. Dredging first began on 27th August 2012 with backhoes; cutter suction dredging commenced on 4th November 2012 and continued through the 2012/2013 wet season to 30 th April 2013. Dredging was suspended during the 2013 dry season and recommenced on 23rd October 2013 and continued through to 12 th July 2014. Construction pile driving began on 24 th August 2013 and continued through to 14 th November 2014. The objectives for this report are: 1. Assess changes in population dynamic parameters of the three coastal dolphin species at the three sites, including population size, losses (mortality + emigration), gains (births + immigration) and temporary emigration (assumes sufficient population sizes of a species at a site to yield adequate samples for analysis) before, during and after the construction of the Projects facilities in Darwin Harbour.

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