Research
Tagging
Whale Sharks: Six whale sharks tagged at Ningaloo Reef
Six whale sharks, ranging in size from four to eight metres, were
fitted with 'SPLASH' tags in May 2005 at Ningaloo Reef, Western
Australia.
Five of the six tags have detached from the sharks, after tracing
their Indian Ocean excursions for periods of 29 days to 136 days
(see map below). The sixth tag hasn't reported in since late September.
More whale shark tagging is likely to take place at Ningaloo in
March 2006.
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Whale shark tracks: The whale shark
track are represented by coloured lines - these are thinner
for the parts of the track when the tag is adrift [last update:
12/11/08
[click on image for larger view]
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The whale sharks were tagged using the latest satellite tags from
Wildlife Computers and tag housings and application methods
developed by the Marine Technology Group at CSIRO Marine and
Atmospheric Research.
The transmitters are contained in a small torpedo-shaped float
that is attached to the shark's dorsal fin via a one-metre tether.
All six tags are transmitting location and swimming depth information
via polar-orbiting satellites fitted with ARGOS receivers.
The tags were attached underwater by a snorkeller using a specially
designed applicator that causes little or no reaction from the sharks.
Tagging is carried out under an Animals Ethics permit.
CSIRO, the Australian Institute of Marine Science, NOAA Fisheries
(Pacific Islands Fisheries Science Center), Hubbs-SeaWorld Research
Institute (California), the WA Department of Conservation and Land
Management, the Commonwealth Government Department of Environment
and Heritage, Wildlife Computers, BHP Billiton Petroleum, Woodside
Energy, and Chevron are partners in the research.
Conservation
Satellite tracking has been attempted for several years off Ningaloo
in response to concerns that the whale sharks that visit this area
are vulnerable to exploitation by fisheries outside Australian waters.
It is hoped these tags will provide longer duration tracks with
accurate locations and swimming depths.
Improved knowledge of the movement patterns of the whale sharks
will form the basis of management and conservation plans for this
species in Australia, and assessment of likely impacts from overseas
fisheries. It also will have educational value for the people participating
in whale shark viewing.
Movements
Little is known about the migration patterns of whale sharks and
what drives them, or how their populations are linked across the
world's tropical and warm temperate seas.
Whale sharks inhabit deep and shallow waters, typically between
latitudes 30°N and 35°S, and prefer sea temperatures of
21-25°C. They appear to be highly migratory, and aggregations
(probably associated with feeding) have been recorded in waters
off Australia, India, Indonesia, Thailand, the Philippines, Taiwan,
Seychelles, Kenya and Somalia.
In Australia, whale sharks are known to aggregate off northern
Queensland in the Coral Sea, and at Ningaloo. Their presence may
be related to seasonal food pulses, such as the mass spawning of
corals at Ningaloo in March and April.
Acknowledgements
CSIRO, the Australian Institute of Marine Science, NOAA Fisheries
(Pacific Islands Fisheries Science Center), Hubbs-SeaWorld Research
Institute (California), the WA Department of Conservation and Land
Management, the Commonwealth Government Department of Environment
and Heritage, Wildlife Computers, BHP Billiton Petroleum, Woodside
Energy, and Chevron are partners in the research.
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Last updated
12/11/08
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