sea trees of Trondheim
||Text Rudolf Svensen
This article was printed in DIVER April 98, the leading British
diving magazine. It is written by Rudolf Svensen, based on an expedition
to Skarnsundet, Trondheimsfjord, Norway, that the Svensen brothers and
my self (Frank Emil Moen) carried through in October 97. The goal of the
expedition was to take the first in situ (at the original place) pictures
of the deep sea corals Lophelia pertusa
(stone coral) and Paragorgia arborea (gorgonian)
Rudolf taking pictures of
My 10-litre deco-gas cylinder thumps rhythmically against my hip
as I battle the current's efforts to knock me off the wall. Below is the
abyss - should I slip and fall I would travel 100m before hitting the bottom.
Ahead I see it, a sea tree, perhaps the first ever to be observed
by a diver. Broadside on to the current, it looks like a big fan. It is
On the opposite side of the sea tree Frank Emil has obviously managed
to settle on firm ground, because I can see his camera flashing continually.
Sea trees (Paragorgia
arborea) normally grow to 1-2m, but can reach as much as 6m.
These horn corals usually live between 200 and 1300m deep, but we have
found the exception, in this shallow habitat in Norway's Trondheimsfjord.
Here unique marine conditions allow such corals to grow within reach of
Sea trees are filter-eaters, picking out their food from the water
that passes through their polyps. The one we have found has all its polyps
out, and thered, flower-like eating organs make a beautiful spectacle.
We would have liked to track down some of the numerous marine creatures
that live on such corals, but we have been at 55m and all too soon have
to return to the surface.
On our way up we pass orange sea bushes Paramuricea
placomus, their flat sides set against the current. These are
smaller relatives of the sea tree, corals that form colonies up to 1m in
height as far up as 25m from the surface.
Colonies are shaped like fans and are known to have many lodgers, particularly
amphipods and isopods. Six thousand five hundred such small crustaceans
have been found on a single sea bush just 35cm high.
We stop at 30m and take pictures of the basket stars sitting on
top of a big sea bush. At 9m we exchange breathing gas and begin a 30-minute
decompression. A week of diving in Skarnsundet at the head of Trondheimsfjord
is about to end.
Eight days earlier we had driven 1200km to arrive, loaded down
with equipment, in the town of Steinkjer, We had spent more than six months
planning this autumn expedition, and besides our photographic and diving
equipment we had a compressor, GPS, portable echo-sounder, laptop computer
with software for dive planning and tide tables, and 15,000 litres of nitrox
80 for decompression.We planned to use a computer program to set up deco
schedules and plan bottom times. Alternative dives would be simulated on
the computer before we hit the water, and each diver brought his own collection
of diving profiles.
As we had six days of diving (one day off for every three days
of diving), we would allow twice as much deco time as necessary on every
dive. Even on shallow night dives down to 20m the plan was to breathe nitrox
80 before ascending.
We hoped not simply to take pictures of sea bushes - which in this
part of the world can be found all over the place - not only of the sea
tree, but of the ratfish and of no less a phenomenon than a coral reef
in Norwegian waters.
|The sun set several hours
ago. We pad along the pier, fully equipped for diving. After today's earlier
meeting with the corals, we are planning to snoop about in the shallows
with our cameras.
Erling and Frank Emil are a few metres ahead of me as we slide down
the narrow crevice in the steep cliff. Our lights creep over the rock,
where sea cucumbers strive to stand firm in the current.
Just below me at about 16m I see a long, narrow fish sliding into Erling's
torchbeam. The next few minutes are chaos.
We have found another stray from the deep, a creature we had been curious
to see for years - the ratfish, or sea mouse.
We had seen it before only in illustrations. Its Latin name, Chimaera
monstrosa, originates from Greek mythology and refers to a fire-breathing
goat with a snake's body and a lion's head. Pictures show a creature with
big, golden eyes and a whip-like tail.
The others catch sight of the ratfish at the same time as me, but it
is not alone - there are five of these "monsters"in the cleft. In their efforts to take pictures while stopping themselves descending,
the divers' fins stir up a lot of mud.
Their lights keep flashing, and I stay above and out of the way until
things calm down. The eyes of the ratfish are very sensitive, and the flashes
obviously make them uneasy. Two of them head towards me. Their heads resemble those of dogs, and
their big eyes sparkle with green brilliance in the light of my torch. One comes close and "snuffs" at my camera before turning back down
and disappearing. moving with incredible grace.
Suddenly they are all gone, leaving in the crevice three dazed divers
amid clouds of mud.
Later in the week we would meet these extraordinary fish several
The sky is bright, and the
sea is almost calm. I am sweating as I arrange the equipment, and the excitement
in the boat is almost tangible. Have we found it? Soon we will have an
I tumble into the water and slide down the shotline. It is low tide, and
there is little current. I need to check that there really is a reef down
here. If I cannot find anything near the mooring, I will play out my line
and make a circular search out from the shotline. The computer indicates
that I am near the bottom. Expectantly I play my light down into the darkness.
A big, white object appears as I land on the dark sand. I identify
it as a sponge (Geodia sp.).
As the light sweeps up the slope, I can just make out something else big
and white on the edge of the cone. I swim somewhat nervously into the unknown. I will never forget that swim. Large fan sponges and trees of
ricegrain corals Primnoa
resedaeformis surround me
, and Norway haddock Sebastes viviparus
hang around in the water.
I feel as if I am in some weird, bewitched forest.
These quaint creatures have never before been disturbed by humans.
Why should such beauty be hidden under masses of cold, dark water?
It really is the Lophelia
reef (Lophelia pertusa), and not one but three. They are
not big; Lophelia reefs of up to 500,000sq m have been found in Norwegian
waters, usually on the Continental shelf between 200 and 400m.
This one is at 55m. "Our reefs" are no bigger than a VW van, but that doesn't
matter. We have found what we were looking for. Carefully I touch the fragile
corals. They are quite hard, like stone corals in warm waters, and the
reef reminds me of a thick thornbush. It bears a striking resemblance to
shallow tropical coral reefs.
I have hardly time to acknowledge a few shrimps and a couple of troll lobsters
before I have to head back to the shotline.
On my way back I pick up a small, loose piece of live coral from the bottom.
Perhaps it was torn off by a fisherman's jig. The deco-stops give me time to absorb the dive, which ranks among
the most wonderful experiences of my diving career. I want to go straight
back down, but there is plenty of time.
Travel by ferry or fly from the UK to Oslo or Bergen, hire a
car for the 650km drive to Skarnsundet, or fly on to Vaernes, 80km from
the site. Accommodation is available at Vangshylla Rorbuer at the western
end of Skarnsundet, in new cottages that sleep up to six and cost £300
a week. Call Svein Gusta, tel. 00 47 74155641. Boats can be rented locally,
air can be obtained from the local fire station or Steinkjer Diving Club
25km away. Viz is best in winter but varies from 0-40m. The water is cold,
between 4-7°C at depth, possibly warmer at the surface in summer.
More details from Rudolf Svensen
on 00 47 51861329.
FIVE days later we leave the reef for the last time. Nothing has
changed. The Norway haddock is still hanging in the water, and the coral
fans wave goodbye. The six films we have taken on the reef are likely to
include pictures of several species never before photographed by divers.
It has been a successful expedition. After only three dives, all our
objectives had been achieved - to see the sea tree, ratfish and coral reef.
Diving in Skarnsundet can be very challenging and is not recommended
for beginners. We constantly had to fight unpredictable currents, sometimes
going in opposite directions along the wall on the same dive. In some places
currents also went straight up or down in a wedge-like formation.
The area off Skarnsundet is biologically very interesting and less
difficult to dive, but it is still possible to see sea bushes in the relatively
shallow and still waters. There are few diveable wrecks in this area, but
for anyone interested in marine fauna it is unique. Divers are likely to
visit in great numbers in coming years.
The picture showsErling Svensen at deco (nitrox 80)
Also take a look at the thumbnail
site from Skarnsundet
Frank Emil Moen is responsible for this site. The pictures are
taken by Frank Emil Moen and Erling Svensen.