00:00 Aerial
view – BAS Rothera Research Station, Antarctica
Wide
of Rothera Research Station
Divers
going into water
Divers
at surface and descending
Notothenia coriiceps- the Arctic Cod, in natural
surroundings
Pull
out from tube worm
Wide
of Antarctic coast
Antarctic
Cod in laboratory tank
Researcher
(Dr Hamish Campbell) pulling fish from tank
c.u.
fish with tag
Guide voice: This is the Rothera Research
Station on the Antarctic Peninsular; an unlikely place to find key
medical breakthroughs. But Researchers from the UK’s
University of Birmingham and the British Antarctic Survey (BAS) are
hoping to do just that - by investigating the behaviour and
physiology of a fish that became isolated in the area, when the
Antarctic circumpolar current was formed, around 30 million years
ago.
The 'Antarctic Cod' (Notothenia coriiceps) an
olive-coloured fish with a broad head and a narrow body, is able to
live in very low temperatures and scientists are eager to find out
how its cardiovascular system has been able to evolve to cope with
such extreme conditions.
00:36 SOT: Dr. Stuart Egginton, Reader in Physiology,
University of Birmingham - “If you and I drop
our core temperature, our deep body temperature just by a couple of
degrees, our heart has real problems pumping the more thick blood
around, and the regulation of that regular beat becomes
problematic.So you start to get some fluttering and irregularities.
And if that body temperature continues to drop by a few more
degrees, than we can have real problems; we can have, basically, a
heart attack. So if we drop our heart temperature by about 10
degrees, we essentially stop. But these animals continue to
beat about 40 degrees lower than our normal body temperature.
So what we're trying to find out is how they regulate that
heartbeat, how they control their cardiovascular system to work in
very low temperatures”.
01:20 c.u.
sign – University of Birmingham Medical School
Wide,
Medical School Building
Dr.
Eggington walking out of laboratory
c.u.
Antarctic Cod in formaldehyde
Guide voice: Controlling heart rate in humans
would be extremely advantageous in medical terms - especially
relating to the problems experienced by human hearts when made to
beat slowly, such as during surgery involving heart-lung
bypass.
01:32 SOT: Dr Stuart Egginton - “The
advantage of cooling people down is then you can do surgery that
otherwise you can't do on the normal body temperature, because the
cellular metabolism is too high, the heartbeat is too high. If we
could really slow the heartbeat down, we could do all sorts
of surgical procedures that are simply not feasible at the
moment. But at present we don't understand how the control,
how the regulation of that heartbeat, breaks down when you cool
it. So therefore we can't avoid those kind of what they call
fibrillations, or fluttering - heart fluttering”.
02:02 Antarctic
Cod in laboratory tank
Researchers
at sea
Divers
surfacing at sea
c.u.
Divers at surface
Divers
climb into boat
Researchers
walking towards Rothera building
Antarctic
Cod in laboratory tank
Guide voice: The fish being studied are unique
to the Antarctic and have developed in complete isolation. In order
to accurately assemble the data they need, researchers must study
the fish in its natural environment throughout the course of the
year. Not so bad during the 24 hour daylight of summer months but
considerably more difficult and dangerous in the darkness of winter
months in temperatures of up to minus 40 degrees. This is a role
that is being undertaken by Dr Hamish Campbell of Birmingham
University.
02:29 SOT: Dr. Hamish Campbell, Post-Doctoral Research
Fellow, University of Birmingham –
“We’re interested in their biology, their unique
physiology, to try to determine firstly, what enables them to live
in such a hostile environment and, secondly, to try and determine
what possible future environmental change may have upon their
biology”.
02:54 c.u.
fish testing equipment
Wide
– Hamish Campbell and testing equipment
c.u.
Antarctic Cod heart rate shown on computer screen
Guide voice: Back in a Laboratory data gathered
at the Rothera Research Station can be studied in order to unlock
the physiological secrets of these fascinating fish.
03:02 SOT: Dr Stuart Egginton demonstrates data on
computer screen - “The kind of data that we
collect is an arterial blood pressure, some estimation of the
respiration or the ventilation of the animal, and then this ECG
signal. Now, what we can see is this. Each deflection
here is a beat of the heart. And what we're interested in is
how those separations vary. This is a - an animal that's
beating at a very high heart rate, and therefore these beats are
quite regular, there's very little variability.But as the heart
slows down, then you get fast beats followed by slow beats at large
intervals. And the extent of that variability is a good
indication of the health of the cardiovascular system, and it also
gives us a good clue as to what neural and hormonal controls are
regulating the rhythm of that heart”.
03:53 Antarctic
Cod in laboratory tank
c.u.
Cod with tagging device
wide
– Cod in tank
Antarctic
coastline and glacier
Floating
ice
Antarctic
coastline
Aerial
shot of Antarctic bay
Antarctic
Cod in natural environment
Guide voice: So – the ways in which the
Antarctic Cod regulates its heart beat could hold the key to more
successful surgical procedures in the future – but
researchers may have to move quickly.
Understanding how well the ‘Antarctic cod’ copes
with the predicted environmental change brought about by global
warming is also expected to help stock management and conservation
of biodiversity within the Southern Ocean. Sadly, evidence suggests
it may also bring about the extinction of this fascinating
creature.
04:22
Ends
