Influence of trawling on the behaviour and spatial distribution of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in Moreton Bay, Australia

2003 ◽  
Vol 81 (12) ◽  
pp. 1947-1955 ◽  
Author(s):  
B Louise Chilvers ◽  
Peter J Corkeron ◽  
Marji L Puotinen
Keyword(s):  
Spatial Distribution ◽  
Bottlenose Dolphins ◽  
Geographical Information ◽  
Foraging Strategies ◽  
Tursiops Aduncus ◽  
Moreton Bay ◽  
Spatial Use ◽  
Free Ranging ◽  
Marine Wildlife ◽  
Southeast Queensland

Sympatric communities of inshore Indo-Pacific bottlenose dolphins (Tursiops aduncus) have previously been identified within Moreton Bay, southeast Queensland, Australia. The two communities overlap in distribution, yet are almost completely socially segregated and forage in distinctly different ways. The correlation between this social segregation, the different foraging strategies, and a human activity (trawling) has previously been demonstrated. This paper investigates the possible effects of trawling on the behaviour and spatial distribution of these two communities. A geographical information system is used to determine the spatial use of each community. The behavioural budgets of both communities showed significantly higher levels of foraging behaviours than reported for most other bottlenose dolphin communities. The spatial use of both communities changed seasonally. These results provide further detail on how human activities may indirectly influence the behaviour and spatial use of free-ranging marine wildlife.

Habitat preferences of Guiana dolphins, Sotalia guianensis (Cetacea: Delphinidae), in Norte Bay, southern Brazil

2010 ◽  
Vol 90 (8) ◽  
pp. 1561-1570 ◽  
Author(s):  
Leonardo L. Wedekin ◽  
Fábio G. Daura-Jorge ◽  
Paulo C. Simões-Lopes
Keyword(s):  
Spatial Distribution ◽  
Habitat Preference ◽  
Geographical Information ◽  
Foraging Strategies ◽  
Fish Stock ◽  
Southern Brazil ◽  
Western Atlantic ◽  
Narrow Strip ◽  
Sotalia Guianensis ◽  
Clayey Silt

Habitat preference and spatial distribution of Guiana dolphins (Sotalia guianensis) in Norte Bay, southern Brazil, was studied from 2001 to 2005. Boat surveys (N = 91) were made to evaluate the spatial distribution of the dolphins. Seven habitat variables were integrated into a geographical information system, and habitat preference was tested using the ‘Neu method’ and a habitat index. The Guiana dolphins did not use all habitat types in the same proportion as were available. Areas used more intensively included, in order of importance: (1) areas with a steep sloping sea-floor; (2) areas further from urban areas; (3) areas further from mangroves; (4) areas near the mouth of the bay; (5) shallow water areas; (6) areas of clayey-silt sediments; and (7) areas close to shore. From 2001 to 2005 there was a shift in spatial distribution and habitat use by the dolphins. The low frequency of use of areas close to urban encroachment and its related impacts to the marine environment raises concern about the coastal habitat destruction. The Guiana dolphin may be considered a habitat specialist, despite its wide latitudinal distribution in the western Atlantic Ocean. The ecological niche of the species may be defined by a narrow strip of shallow coastal waters (mostly < 30 m) bordering the coastline. The shift in the spatial use was probably linked with changes in the abundance of important prey of the species and possibly was caused by the collapse of a fish stock in the study area region. Different habitats may favour different assemblages of prey and consequently different foraging strategies by the dolphins. Human-related habitat alterations throughout the range of this species are likely to affect dolphins' ecology in many ways and, thus, must be evaluated and mitigated to conserve their critical habitats.

scholarly journals Signature whistles in free-ranging populations of Indo-Pacific bottlenose dolphins,Tursiops aduncus

2013 ◽  
Vol 30 (2) ◽  
pp. 512-527 ◽  
Author(s):  
Tess Gridley ◽  
Victor G. Cockcroft ◽  
Elizabeth R. Hawkins ◽  
Michelle Lemon Blewitt ◽  
Tadamichi Morisaka ◽  
...  
Keyword(s):  
Bottlenose Dolphins ◽  
Tursiops Aduncus ◽  
Signature Whistles ◽  
Free Ranging

Reduced Detection of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) in an Inner Harbour Channel During Pile Driving Activities

2015 ◽  
Vol 41 (4) ◽  
pp. 455-468 ◽  
Author(s):  
Estênio G. Paiva ◽  
Chandra P. Salgado Kent ◽  
Marthe Monique Gagnon ◽  
Robert McCauley ◽  
Hugh Finn
Keyword(s):  
Bottlenose Dolphins ◽  
Pile Driving ◽  
Tursiops Aduncus

The Archaeology of the Peel Island Lazaret: Part 1: Survey

2002 ◽  
Vol 13 ◽  
pp. 31 ◽  
Author(s):  
Jonathan Prangnell
Keyword(s):  
Conservation Planning ◽  
Archaeological Survey ◽  
Landscape Modification ◽  
Moreton Bay ◽  
Nineteenth And Twentieth Centuries ◽  
Southeast Queensland

<p>An archaeological survey on Peel Island in Moreton Bay, southeast Queensland, was conducted to assist the conservation planning for the Peel Island Lazaret (PIL), one of a number of institutions housed on the island during the nineteenth and twentieth centuries. The survey revealed a patterning of artefacts across the island as well as landscape modification related to its Aboriginal and European institutional uses.</p>

Pregnancy Cravings: Visitation at a Food-Provisioning Site is Driven by the Reproductive Status of Bottlenose Dolphins

2020 ◽  
Vol 15 (3) ◽  
pp. 237-248
Author(s):  
Valeria Senigaglia ◽  
Lars Bejder
Keyword(s):  
Prey Availability ◽  
Southern Oscillation ◽  
Bottlenose Dolphins ◽  
Reproductive Status ◽  
Food Provisioning ◽  
Human Interactions ◽  
Increase Risk ◽  
Lactating Females ◽  
Tourism Attractions ◽  
Marine Wildlife

Marine wildlife tourism attractions often use food rewards to ensure close-up encounters with freeranging animals. In Bunbury, Western Australia, the Dolphin Discovery Centre (DDC) conducts a foodprovision program where bottlenose dolphins (N = 22; between 2000 and 2018) are offered food rewards to encourage their visitation at a beach in front of the DDC. We used historical records on individual beach visits by adult female dolphins collected by the DDC from 2000 to 2018 to develop generalized mixed effects models (GLMM) to test whether the frequency of beach visitation was influenced by their reproductive status (pregnant, lactating, nonreproductive) or climatic events (El Niño-Southern Oscillation phases) that could affect prey availability. We also quantified the behavioral budget of dolphins during food-provisioning sessions and documented intra- and interspecific aggressive behaviors using individual focal follows collected in 2017–2018. Provisioned females spend most of the time resting within the interaction area (66.3%) and aggressive interactions arise as a consequence of dominance behavior over food access. Visitation rates were most influenced by reproductive status with pregnant and lactating females visiting the provisioning area more frequently (z = 2.085, p = 0.037 and z = 2.437, p = 0.014, respectively). Females that frequently visit the provisioning area expose their dependent calves to regular human interactions at an early age when they are more susceptible to behavioral conditioning. Such experiences could cause the loss of awareness towards humans and promote maladaptive behaviors such as begging that increase risk of entanglement in fishing gear, boat strikes, and propeller injuries.

Whistle Characteristics of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) in the Fremantle Inner Harbour, Western Australia

2016 ◽  
Vol 44 (1) ◽  
pp. 159-169 ◽  
Author(s):  
Rhianne Ward ◽  
Iain Parnum ◽  
Christine Erbe ◽  
Chandra Salgado-Kent
Keyword(s):  
Western Australia ◽  
Bottlenose Dolphins ◽  
Tursiops Aduncus
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