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MCSS
are pleased to announce some very good news with respect
to funding and support for the whale shark monitoring
programme for the 2007 and 2008 seasons. The Save Our Seas
Foundation has extended the funding it has provided over
the last two years for a further two years. This funding
is aimed primarily at developing a satellite tagging
technique that does not require the use of tethers or
immobilising the study animal that will help define the
migratory paths of whale sharks from Seychelles and
identify the factors affecting their movements. The
project will provide information to local and
international authorities to allow the informed
development of conservation and management plans for this
species.
The project will be implemented by programme leader David
Rowat with assistance from Dr. Mauvis Gore and Dr. Rupert
Ormond of the University Marine Biological Station
Millport, the marine field station of the University of
London. The plan is to deploy at least three fin-mounted
SPLASH tags each year that will not only provide
information on the animals’ movements but also provide
oceanographic data of the water masses they encounter. It
is hoped that this will build substantially on the pool of
information already gathered from the satellite tracking
programme that MCSS has successfully implemented over the
last six years as well as refining attachment techniques
that can be used in a number of other fields of shark
research.
Dorsal fin-mounted tags have been used successfully on
several species of shark but have to date required the
immobilisation of the shark to allow attachment, something
that would be particularly difficult with even a small
whale shark. The benefits of the system are the longer
periods of attachment as there is no tether to become
entangled in floating seaweed or debris and they are less
likely to be damaged by the animal rubbing itself on the
sea-bed or coral structures as some sharks (including
whale sharks) seem to do.
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Fin
mount tag being attached to the dorsal fin of a
restrained great white shark and a released shark
with tag attached. Photos: M.C.Scholl and Marine
and Coastal Management South Africa.
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The focus of the programme will thus be the development of
an instantaneous attachment method that will secure the
tag safely to the dorsal fin thus allowing the tag to
transmit to the satellite system whenever the dorsal fin
breaks the surface, which is quite regularly in whale
sharks. A similar system is being developed in Australia
based upon a C-clamp that is ‘riveted’ to the front of
the dorsal fin; this device was trialled two years ago but
was used with towed tags on short tethers. While this did
increase the time that the tags remained attached, they
still had problems with the tethers accumulating seaweed
and so their new system is a totally fin-mounted unit with
no tethers.
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