Data

Movement Patterns and Habitat Usage of Shark Bay Dugongs - Thesis

Australian Ocean Data Network
Holley, David
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://catalogue.aodn.org.au:443/geonetwork/srv/api/records/52f394a0-23b5-11dc-a78e-00188b4c0af8&rft.title=Movement Patterns and Habitat Usage of Shark Bay Dugongs - Thesis&rft.identifier=https://catalogue.aodn.org.au:443/geonetwork/srv/api/records/52f394a0-23b5-11dc-a78e-00188b4c0af8&rft.description=The extent and scope of the seasonal distribution movements and habitat usage of dugongs fitted with remote location recording and transmitting devices within the Shark Bay World Heritage Property (SBWHP) on the mid-West Coast of Western Australia were measured from 2000-2002. In addition to defining movement patterns and habitat preferences of individual dugongs an aerial survey was undertaken during the summer of 2002 to define population distribution and abundance estimates.Maintenance and Update Frequency: notPlannedStatement: The 'chase and catch' procedure was used in this study to capture dugongs in Shark Bay to attach 18 remote tracking tags at locations within the Shark Bay World Heritage Property (see thumbnail). Of the 18 tags, eight were PTT satellite tags, eight were GPS data logger tags, and two were combination PTT/GPS tags capable of both transmitting and logging. All units incorporated a VHF radio transmitter on its own frequency to enable each unit to be tracked at sea. (for full technical descriptions of the tags see Chapter 2 of thesis)Statement: To assess fine scale habitat structure and identify the composition, density and biomass of seagrass forage species that occurred in areas preferred by dugongs (the 50% kernel contours calculated from positions obtained from the GPS tags), a total of 14 sites were sampled. Sites were chosen based upon a subset of the spatial and temporal distribution recorded from two of the GPS tags deployed on female dugongs during their autumn-winter-spring distribution pattern. Habitat surveys were conducted during August 2002. At each site, four 50m transects were laid out on the benthos in a north, south, east and west direction respectively from a randomly located point. A video of the benthos was then taken along each individual transect at a constant speed and height of 50cm above the bottom. Seagrass percentage cover and composition were later determined from the video through consensus of three observers. In addition, eight replicate 0.5m2 quadrats were sampled by SCUBA divers at locations selected randomly over the four transects at each site. Seagrass percentage cover was estimated within each quadrat. Shoot density was determined within a 0.1 m2 sectioned corner of the quadrat after which the seagrass within that corner was harvested for above ground biomass determination. Biomass was measured for dry weight by drying samples at 600C for a 48 hour period.&rft.creator=Holley, David &rft.date=2007&rft.coverage=westlimit=113; southlimit=-27; eastlimit=115; northlimit=-25&rft.coverage=westlimit=113; southlimit=-27; eastlimit=115; northlimit=-25&rft.coverage=uplimit=25; downlimit=0&rft.coverage=uplimit=25; downlimit=0&rft_subject=oceans&rft_subject=Biosphere | Ecological Dynamics | Feeding Habitat&rft_subject=Oceans | Marine Biology | Marine Mammals&rft_subject=RANGE CHANGES&rft_subject=EARTH SCIENCE&rft_subject=BIOSPHERE&rft_subject=ECOLOGICAL DYNAMICS&rft_subject=SPECIES/POPULATION INTERACTIONS&rft_subject=41 206001&rft_subject=Dugong dugon&rft.type=dataset&rft.language=English Access the data
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Brief description

The extent and scope of the seasonal distribution movements and habitat usage of dugongs fitted with remote location recording and transmitting devices within the Shark Bay World Heritage Property (SBWHP) on the mid-West Coast of Western Australia were measured from 2000-2002. In addition to defining movement patterns and habitat preferences of individual dugongs an aerial survey was undertaken during the summer of 2002 to define population distribution and abundance estimates.

Lineage

Maintenance and Update Frequency: notPlanned
Statement: The 'chase and catch' procedure was used in this study to capture dugongs in Shark Bay to attach 18 remote tracking tags at locations within the Shark Bay World Heritage Property (see thumbnail). Of the 18 tags, eight were PTT satellite tags, eight were GPS data logger tags, and two were combination PTT/GPS tags capable of both transmitting and logging. All units incorporated a VHF radio transmitter on its own frequency to enable each unit to be tracked at sea. (for full technical descriptions of the tags see Chapter 2 of thesis)
Statement: To assess fine scale habitat structure and identify the composition, density and biomass of seagrass forage species that occurred in areas preferred by dugongs (the 50% kernel contours calculated from positions obtained from the GPS tags), a total of 14 sites were sampled. Sites were chosen based upon a subset of the spatial and temporal distribution recorded from two of the GPS tags deployed on female dugongs during their autumn-winter-spring distribution pattern. Habitat surveys were conducted during August 2002. At each site, four 50m transects were laid out on the benthos in a north, south, east and west direction respectively from a randomly located point. A video of the benthos was then taken along each individual transect at a constant speed and height of 50cm above the bottom. Seagrass percentage cover and composition were later determined from the video through consensus of three observers. In addition, eight replicate 0.5m2 quadrats were sampled by SCUBA divers at locations selected randomly over the four transects at each site. Seagrass percentage cover was estimated within each quadrat. Shoot density was determined within a 0.1 m2 sectioned corner of the quadrat after which the seagrass within that corner was harvested for above ground biomass determination. Biomass was measured for dry weight by drying samples at 600C for a 48 hour period.

Notes

Credit
Dr Nick Gales
Credit
Dr Paul Lavery
Credit
Department of Conservation and Land Management (now DEC)
Credit
Shark Bay Yadgalah Aboriginal Corporation
Credit
James Cook University (JCU)
Purpose
To provide management agencies with information important for the continued conservation and management of the Shark Bay dugong population.

Created: 26 06 2007

Data time period: 2000-03 to 2002-07

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115,-25 115,-27 113,-27 113,-25 115,-25

114,-26

text: westlimit=113; southlimit=-27; eastlimit=115; northlimit=-25

text: uplimit=25; downlimit=0

Subjects
41 206001 | BIOSPHERE | Biosphere | Ecological Dynamics | Feeding Habitat | Dugong dugon | EARTH SCIENCE | ECOLOGICAL DYNAMICS | Oceans | Marine Biology | Marine Mammals | Range Changes | SPECIES/POPULATION INTERACTIONS | oceans |

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Other Information
(Masters thesis)

uri : http://ro.ecu.edu.au/theses/70/

Identifiers
  • global : 52f394a0-23b5-11dc-a78e-00188b4c0af8