Tags (Underwater Sonic transmitters) make it possible
to have a better understanding of movements of
individual animals on an ongoing basis.
underwater receiver, or a series of receivers,
can be located at strategic locations along the
reef slope. They will record when a tagged animal
is within a certain distance from the receiver.
This signal is constant as long as the animal
remains within the reach of the transmitter. Once
the animal moves beyond the transmission distance
the signal will cease. (See diagram on the right)
transmitters are currently being used in the Coral
Sea as part of a home range study of reef sharks
at Osprey Reef.
At Lady Elliot Island, sonic transmitters be attached
to three manta rays. the range will be somewhere
between 500 and 1000 metres
of the transmitter is 48mm long x 16mm diameter.
The tags will be delivered via a hand spear apparatus
by divers on scuba gear, and the tags will be
inserted in the fleshy area on the back of the
animal. Similar methodology has been used for
tagging white pointer sharks in the Spencer Gulf
area of South Australia.
is expected that apart from the initial 'fright'
of being jabbed with the tag, disturbance to the
animals will be minimal. Field work for this part
of the project was undertaken in early May 2001.
website is maintained by Lady Elliot Island in association with the Australian