million years of evolutionary history,
sharks can quickly home in on which
way you are facing and decipher body
movements. White sharks are very
much intelligent enough to be able to
tell the difference between us and a
natural prey item 99.9% of the time.
However, it is unwise to push them in
their territory, so the number of dives
with them are limited and kept strictly
to scientific purposes.
White shark individuals are easily
identified by the distinct pattern across
their gills. This is where the white of
the underbelly meets the dark silver
of their dorsal colouration, forming a
pattern across the gills that is like a
fingerprint for sharks. Working with
professional photographers who shoot
in high resolution allows us to zoom
in on the images and videos to examine
small details like tumors and other
morphological scars and features.
Biopsies of skin and muscle tissue
samples are sent to a lab to look
at the genetics and stable isotopes.
Muscle samples give us insight into
the types of prey the shark has been
consuming, while examining the
skin can identify distinct genetic
codes that can be compared to the
samples taken from pups that are
caught near the continent to see
where possible pupping grounds
are. At this point in time, no person
has ever been able to record a white
shark giving birth and pupping
grounds are still theoretical. We hope
that a better understanding of the
movements of white sharks can help
support conservation efforts to expand
protection for them.
Unfortunately, white shark
populations around the planet are
dropping and the iconic species is
disappearing. White sharks are very
slow to reproduce, they pup few young,
and we don’t know how many of their
pups actually survive to adulthood.
I’ve been seeing many of the same
larger individuals every one to three
years over the last 10 years at Isla
Guadalupe – a testament to just how
few individuals there are in the area.
The photo identification record for
Isla Guadalupe has only around 200
individuals, and many juveniles are not
yet of reproductive range, and may not
survive long enough to reproduce due
to the high chances of being caught in
nets, longline fisheries, killed for sport
or for shark’s fin soup – the number
one reason sharks are being killed
around the planet.
You can help save white sharks by
supporting good scientific efforts, but
more so by supporting good legislative
action to better protect them and also
by making daily consumer choices that
don’t support the killing of sharks.ABOVE: Ramsey filming the behaviour of the sharks
OPPOSITE PAGE: Ramsey swimming with a great white
IMAGES: Juan Oliphanthttp://www.oneoceandiving.com