Page 52 - SAMCoT_2013

52 SAMCoT • ANNUAL REPORT 2013
sounds of an icebreaker crunching through an ice ridge.
Those were just a few of the many research objectives
achieved by the multinational team who completed
the two-week cruise in the icy waters off northeast
Greenland.
“This gave us a great opportunity to test out many of
our new technologies,” said Raed Lubbad, NTNU cruise
Leader. “We were able to build our database and collect
as much full-scale data as possible.”
The Swedish icebreaker Oden left Longyearbyen,
Svalbard on 19 August and returned late in the evening
on 1 September. The two-week cruise was designed to
allow the 28 ice engineers and scientists to measure
and quantify different aspects of sea ice, icebergs and
their interaction with the ship. Five marine mammal
researchers were also aboard the vessel, where they
conducted acoustic research and combined conven-
tional marine mammal observations with more high-
tech approaches.
Silent but noisy
Researchers in the Marine Mammal Observation
group reported that they were very excited about their
measurements of underwater sounds as the icebreaker
moved past icebergs and broke through larger ice floes.
The group says that the Arctic Ocean can be seen as both
themost silent andmost noisy of all oceans. The breakup
or collapse of an iceberg can be noisy, but a thick layer
of ice can insulate the underwater world from surface
noises. As researcher Michel André observed, however,
scientists have relatively little data on how man-made
underwater sounds, such as the crunching of the boat
through ice ridges, propagate under the ice.
André, who is director of the Laboratory of Applied
Bioacoustics at the Technical University of Catalonia
BarcelonaTech (UPC) in Spain, says that the data the
group collected from the cruise is particularly valuable
for this reason, especially as increased activity in the
Arctic Ocean boosts the amount of man-made noise in
the water. The information can be used to conduct a risk
assessment for the possible impact of noise on marine
mammals.
The scientists measured the sound using a buoy
equipped with a hydrophone and a sound recorder,
deployed from the ship and left in the ocean during the
ice breaking trials. “Then the buoy has to be found again,
and this is itself a challenging task,” said Statoil biolo-
gist Jürgen Weissenberger, who coordinated the marine
mammal group. “Finding and taking a small buoy on
board requires the skills of an experienced icebreaker
crew, and that we had on board Oden.”
André during noise measurements at oARTC2013.
Photo: Jan Durinck Photo: Andy Mahoney
Hydrophone buoy and Ivory gull.