|
Interview with a shark diver
Plunge into icy waters with an experienced shark researcher and Arctic diver
By Tobi McIntyre
Ever wonder what it’s like jumping into a narrow triangle in the ice — on
purpose — to see what flows beneath the frozen water? CG Online asks with Jeffrey
Gallant, regional director of the Shark Research Institute of Canada and experienced Arctic
diver, for his take on plunging into the Saguenay fjord in search of Greenland sharks.
CG: What’s the first feeling that comes over you when you jump through the
ice into freezing water?
JG: Excitement! It’s like being Alice going down the rabbit hole, crossing into
another dimension where gravity and your daily preoccupations are replaced by weightlessness
and the unknown. No matter how often we dive at the same site, we never know what’s
going to surprise us and that’s one of the things that keep us coming back.
 CG:
How long does it take to adjust to that environment?
JG: Diving in these conditions requires careful planning and mental preparation. With
experience, you adjust as soon as you hit the water. The first thing you notice is the
sudden and welcome weightlessness after lugging all of the heavy gear across the ice. Then
as you peer down into the depths, you see nothing but darkness and you get your first taste
of the water, the taste of adventure! On the first dive of the expedition, you never really
know what’s down there.
CG: Can you explain thermohaloclines and how it affects your diving experience?
JG: The thermohalocline is where the brackish surface layer meets the seawater layer
at a depth of about 10 metres. The thermohalocline is a fuzzy zone where there is an abrupt
variation in salinity and temperature. This creates a one-metre-thick layer of water that
has the reddish appearance of grenadine. You can see your dive computer but you can’t
read any of the numbers. It’s like looking at a distant object that is distorted
by heat emanating from hot pavement. It only lasts for a few seconds and then we cross
into a marine environment.
CG: Is there any life down there? Can you compare diving there to diving in tropical
waters?
JG: There is a lot of life down there. In fact, small jellyfish are encountered throughout
the saltwater column and myriad lifeforms cling to every bit of solid substrate on the
bottom. Some of the sea life we observe is quite similar to what you would see in warmer
waters. Like the Caribbean, the Saguenay Fjord also has sponges, tubeworms and anemones.
The only difference is that these are coldwater species that can’t be seen in the
tropics. Exoticism is thus in the eye of the beholder. Best of all, we are still trying
to identify some of the animals and invertebrates that we observed during our two winter
expeditions, including sponge and squid species that we had never seen before.
CG: Did you have any experiences diving in the Saguenay fjord that caught your breath,
made you wonder, or gave you the chills?
JG: I have been diving in many parts of the world and I have to admit that the Saguenay
is a spooky place. Diving in total darkness when you are massively baiting for a possible
seven-metre shark, you always wonder what’s ahead or even worse, what’s coming
up behind you. The way our lights suddenly lit up boulders and created moving shadows certainly
caught my breath a couple of times on the first dive. It is quite exciting, and I guess
I kind of like it.
CG: What is the quality of light like under the ice? Do you have to fight against
claustrophobia, disorientation?
JG: Hardly any light makes it through the snow and ice and the reddish layer of brackish
water absorbs the rest. Beyond five metres, we are in total darkness, thus we use very
bright dive lights mounted on helmets to light our way. Our cameras also require powerful
strobes and video lights to film otherwise unseen lifeforms. Although it is easy to orient
ourselves vertically, it is impossible to locate the dive hole without a lifeline. Losing
your link to the surface is the ice-diver’s ultimate nightmare and it crosses my
mind on every Saguenay dive.
CG: How does your body react to being in that water? What gets cold first?
JG: Getting into the water is actually a relief when the surface temperature is a bone-chilling
-30°C. The temperature of the brackish top layer hovers around 4°C while the saltwater
layer is between -1 and 2°C. When you slide into the hole, the first thing you notice
is the cold water on your face. It’s like someone has put clothespins on your lips.
It hurts for less than a minute and then they go numb. Since we wear thick neoprene drysuits,
the rest of our body doesn’t feel the cold. In fact, we often surface sweating after
an average 20 minutes underwater.
 CG:
You say it is even more unique than the Arctic. How so? The diving experience or the
environment itself?
JG: The Arctic is a big place with similar conditions found at the same latitudes. You
can dive at two different locations hundreds of kilometres apart and observe the same overall
picture. The Saguenay is a relatively small place and it presents an environment unlike
any other at the same latitude anywhere in the world. Because of its very cold waters year-round,
we can observe lifeforms that are normally found at much higher latitudes without the logistical
difficulties of setting up an Arctic expedition. Its very steep profile also makes for
high densities of certain species that inhabit specific depths. This results in a form
of species layering. It’s like climbing down the side of a skyscraper where each
floor houses a different company.
CG: What sort of precautions do you take when diving in a fjord versus diving somewhere
less dynamic?
JG: Diving under the ice in the Saguenay is much more challenging than diving in a lake.
Darkness and especially strong currents dramatically increase the risk factor. All of our
dives were planned at specific times between tidal movements. That left us with only two
short dive windows per day. Regardless of these factors, no matter how experienced or well-prepared
you are, and no matter where you dive, your main concern should always be human error.
When ice diving, every member of the team, both underwater and at the surface, has to remain
alert and focused at all times. Knowing how to read and respect environmental conditions
is also crucial, especially in a dynamic environment such as the Saguenay. Current under
ice is unforgiving. Never challenge the ocean for one more photo or just because you drove
five hours to get to the dive site. There is always tomorrow or next year, and patience
eventually pays off. We did finally see the Greenland shark and it’s only the beginning
of an even greater adventure.
CG: What type of diving experiences have you had? Where was your favourite dive?
JG: Diving in Canada is incredibly underestimated. You could dive here your entire life
and never surface disappointed. I’ve been diving for more than 20 years and there
are so many places I still haven’t seen for myself. Saguenay dives are among my favourite
because you just never know what you’ll see. However, although I like to think that
every dive I have ever done was just as rewarding as the last, diving with the Greenland
shark in the St. Lawrence tops my list of best-ever dives. After all our efforts and research,
I never felt so excited in my life. And since diving is always full of unexpected surprises
and new discoveries, especially in Canada, I know it will happen again.
Images courtesy of Aqualog.com
top
|
