Whale
shark spy-cam
Feature
by Kerie Hull
June 20, 2003
Australian Institute of Marine Science
researchers set out to capture something no one
has ever seen before, but they got much more
than they bargained for. By tethering a video
camera to the back of a whale shark they were
hoping for an insight into the daily life of
whale sharks but they also discovered how the
whale sharks have been cleverly thwarting
scientists attempts to track their every move.
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 Dr. Mark
Meekan.
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Whale Shark
Photo: Peter Nicholas
(For a larger view of this image see
bottom of this news feature)
Off the north coast of
Western Australia scientists aboard the AIMS research vessel
RV Cape Ferguson
are overcome with relief as they watch a clear water
mass roll in, transforming grey desolate swells to clear
calm, brimming with sea life. Chasing an abundance of
bait fish and krill brought in by the change, are hungry
whale sharks, right on cue. After seven days of choppy
seas and too few signs of whale sharks, the break in the
weather is sheer delight for cruise leader Mark Meekan
who is hoping to catch a world first… a spy’s-eye
view of a whale shark at mealtime.
Using a "crittercam",
a camera (provided by the National Geographic Society)
attached to the back of a whale shark, Dr Meekan hopes
to witness what has previously been hidden from
researchers - a detailed profile of where the animals
spend most of their time, exactly how they feed and
interact with their own kind, wherever they roam.
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They’re the world’s biggest fish, and so mild mannered
tourists travel the world over to snorkel with them. But they
usually inhabit oceanic waters far from shore, hence little is
known about them.
It’s not known whether the annual
aggregation at Ningaloo Reef is unique or whether the animals
that occur here are part of a global population. Where they go
after Ningaloo and where they breed also remains a
mystery.
For the AIMS scientists who have been searching for answers
over the past four years, resolving some of these questions
this tagging trip is more critical than ever because it will
be the last, unless funding circumstances change.
While three different types of tags will be deployed during
the research trip, the pride of the project is the "crittercam",
never before fitted to a whale shark.
It all starts with a surveillance plane circling overhead to
spot the whale sharks. Some of Meekan’s team leave the
larger research vessel, the Cape Ferguson, to join divers on a
smaller boat. The divers gear up in readiness for a specimen
to tag. The whales are plentiful ranging from
"babies" at a mere four metres long to one
individual 12 metres the spotter plane pilot says is the
biggest one he has ever seen at Ningaloo.
It takes a steady hand to plunge into open water, sneak within
two metres of the animal, reach out the applicator pole with
dart head and camera attached, and successfully position the
camera to the dorsal surface. There’s no other way… but
the researchers who do it relish the opportunity to brush
shoulders with the world’s largest fish.
Meekan recalls the thrill, " Once you’re in the
water you no longer have a good vantage point. You have to
rely on the boaties to guide you into the path of the shark.
Once you’re in position you then have to swim hard to keep
up with the shark travelling at about two knots and get enough
momentum to be able to precisely position the tag.
"They’re
very curious creatures. They often swim directly towards
you to check out what the hell you are.
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All you can see
is a gaping mouth bigger than a circle you could make
with your arms… actually a lot bigger," he says
as he reconsiders.
Often we are
bobbing around waiting in the boat for more than five
hours for a shark to tag… once you have a shark lined
up you have a window of only 30 seconds to get the job
done. It’s not a matter of being scared … I’m just
trying to stay focussed on not dropping the bloody pole
or screwing up."
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Diver
approaching the dorsel
fin of a Whale Shark.
Photo: Peter Nicholas
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The team were well aware the moment the spotter plane pilot
alerted the crew of a five- metre whale shark nearby they’d
be embarking on world first attempt at mounting a camera to a
whale shark. What the scientists didn’t realise was the turn
of events to come would dramatically change the way they
approach their tagging programme.
"The diver swam up to the shark and deployed the
crittercam …without so much as a flinch the shark took the
crittercam straight to the bottom," Dr Meekan recalls.
And next, "The film showed a swirl of sand, the shark
rolling on its side and scratching the camera off … and
finally a lovely view of the sand from 60 metres and rising,
as the Crittercam floated to the surface," he says. After many
months of planning it took no less than a minute and a
half for the shark to figure out how to shed the camera.
The second attempt yielded the same behaviour.
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"Clearly
the sharks are not as dumb as we thought they were, and
they obviously don’t want the tag attached," Dr
Meekan says. "Seeing this behaviour is really
interesting because it explains why we’ve had such
problems in the past attaching the satellite tags to the
sharks."
"We had no idea what was happening to these tags we
thought were firmly in place. Now a lot of things are clear.
It also explains problems other researchers have had in trying
to tag these creatures," says the cruise leader.
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 The
critter-cam being
positioned.
Photo: Peter Nicholas
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For the scientists it was a positive sign. They are now
able to see a way forward and devise a better position for the
equipment to be rigged. Dr Meekan says,
"We looked at the remora- a fish that hitches a ride
on the sharks- to get and idea of what position works. Like
fleas on a dog we have to find a spot they are less likely to
scratch them off."
After these false starts, the team finally managed to
deploy the camera on a seven metre female. The research team
had finally hit pay dirt.
It is always a gamble, but the odds of getting the camera
equipment back are fairly good because this camera
automatically disconnects as it is designed to. It should have
been a simple search and rescue operation. A VHS signal should
have been detected via an aerial on the camera now floating
somewhere at the surface but scientists feared a modification
made to the camera could be sinking to aerial out of range.
An agonising six hours had passed and only moments before
the RV Cape Ferguson was due to leave the area the camera was
found.
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The video that emerges is "magic" says Dr
Meekan. "It’s like you’re holding onto the dorsal fin
of the shark and it’s taking you for a dive. It’s just
brilliant," he says.
The film is crisp and clear and to
the researchers it is pure gold. These are scenes previously
hidden from scientists, but now they could see what the whale
sharks sees, as Meekan recalls, "We followed the shark
along the bottom. Watched it swimming over the contours, and
the schools of fish playing around its head. It doesn’t swim
during a dive, but rather performs an enormous graceful glide
gathering quite a bit of momentum before levelling out just
off the bottom."
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Moment
of contact.
Photo: Peter Nicholas
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"It proves we can deploy
the crittercam and use it to monitor whale shark
behaviour," Meekan says.
"Because the
head of the whale shark is so huge it blocks any view of
feeding. But what we do see is spectacular. As the shark
glides like a submarine straight to the bottom, it’s colour
changes. The white spots on its back turn a brilliant blue,
and fish scatter as the shark plummets to depths," Dr
Meekan says.
"No one has
ever done this before. Our entire interaction with whale
sharks is based on the time they spend at the surface in the
15 minutes or so between dives . We have no idea what they do
when they are out of reach of snorkellers and beyond our view
in deep water.
Captured on film
is the bouncing behaviour scientists have witnessed from the
surface. The sharks dive from the surface to the bottom like a
yo-yo Meekan says. "A whole industry is based on the
whale sharks coming to the surface but we still don’t know
why they need to do this.
The crittercam will be a useful tool
to help us interpret the dive data we have collected from the
surface. At the moment it’s just a squiggle on graph. We
assume a lot without having any means to check on our ideas -
now we can. We can put the dive pattern data and the
crittercam information together to validate and interpret our
data.
The technology
used to spy on mealtime is more than just a video camera. As
well as recording film, it’s a miniature laboratory
archiving water temperature and depth.
The package is wrapped
in a waterproof housing. In all, it’s about two hand spans
in length and shaped like a torpedo with a windscreen at the
front for the camera.
The cruise
hasn’t been all smooth sailing. Twenty-five knot winds and
two metre plus swells at the beginning of the trip created its
own dramas. Diving with an animal the length of a bus and
attaching a dart head the size of thumb nail precisely behind
the dorsal fin was no easy feat in lumpy seas. Meekan says,
"It was like trying to drink a cup of coffee on a
roller-coaster. If tagging whale sharks was simple everyone
would have done it by now. It’s not. You have a big animal
coming past you at great speed and as you can’t stop or
capture the animal, you only have one shot at it, " he
says.
Despite the
elements, several acoustic tags were successfully deployed, in
collaboration with Dr John Stevens of CSIRO, Australia’s
foremost shark expert. These tags send out a signal – a
"ping" detected by a hydrophone on board the smaller
of the boats enabling scientists to track short term movements
of the animal.
It’s like a
highly sophisticated game of follow the leader over a 24 hour
period. Dr Meekan says, "We followed the shark into dense
patches of bait fish and krill. We dropped an underwater video
camera over the side of the boat to confirm what the sonar
suggested the sharks were chasing."
"A
consistent pattern seems to be that the sharks are
coming in from off shore targeting krill and bait fish
accumulations along deep-sea the ridge lines created by
ancient sea levels," Dr Meekan says.
Still questions remain:
where the sharks go after their spell at Ningaloo? How
they navigate around the world’s oceans, where the
adults go to breed, and how many sharks turn up at
Ningaloo every year? What scientists do know is their
popularity on restaurant menus in South East Asia has
made them a target of the commercial fishing industry,
an unrestrained harvest that may lead to the demise of
the species.
Dr Meekan’s research
will now shift to studying the long-term movements of
whale sharks that will be located via satellite. In
collaboration with NOOA and Hubbs Seaworld research
Institute from the US, four sharks have been rigged with
PAT (pop-up archival tags) that are designed to gather
data on the sharks’ location, depth and the water
temperature around the animal for eight months and then
fall out, floating to the surface to transmit their data
to satellites. "It’ll be an intense eight months
anxiously waiting for results," he says.
The aim of this research trip
is gaining insight into the whale shark’s life and how
humans can help protect the species. "It’s unique, no
one has ever seen this before. I hope these spectacular
crittercam images will help us understand what draws these
animals to Ningaloo and ultimately to protect this
resource," says Dr Meekan.
To date the whale shark is
internationally listed as "threatened" and there’s
a campaign to have that level of protection stepped up.
"The objective of the "crittercam" project, and
one of the reasons we have been supported by and able to work
in collaboration with the Department of Conservation and Land
Management of Western Australia is that the information we are
gathering about the animals may actually make the difference
needed to coexist peacefully with these incredible
animals," Meekan says.
A
graceful Whale Shark glides by.
Photo: Peter Nicholas
For more information
contact
Dr Mark Meekan,
AIMS scientist
Email: m.meekan@aims.gov.au
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20030620