http://www.eurekalert.org/pub_releases/2006-12/awif-fab_1122206.php
Public release date: 22-Dec-2006
4 Arnoux's Beaked Whales observed from Polarstern expedition
The Arnoux' Beaked Whales is one of the least known species of
the Beaked Whales family (Ziphidae).
Click here for more information.
On the 17th of December, Meike Scheidat & Linn Lehnert, the whale
watchers on board of Polarstern, made a remarkable cetaceans sighting:
Four Arnoux's Beaked Whales (Berardius arnuxii), observed from the
helicopter.
The Arnoux's Beaked Whales is one of the least known species of the
Beaked Whales family (Ziphidae), itself poorly known in general.
Arnoux's is one of the biggest species amongst beaked whales. The ones
observed were probably 9 metre long. These deep-sea feeding whales are
particularly sensitive to underwater acoustic disturbances. The
pictures showed a whole array of scars on their skin, which are already
under investigation. Some of these scars could have been inflicted by
orcas, their potential predators, or by squids, their most common
preys, as proposed by Elaina Jorgensen one of our cephalopod specialist
onboard. Other scars could be caused by cookie-cutter sharks, which
would imply big migration between the subtropical waters where these
sharks are found and the ice-edge (64°06 S) where they were observed.
Supply of German Neumayer station
After crossing the Atlantic and the sea ice of the Atka Bay Polarstern
supplied the German research station Neumayer on the Ekström Ice Shelf
with food and fuel. Helicopters brought up hoses to refill eight
20,000-liter tanks with diesel fuel. The tanks were sitting on sledges
ready for later transportation to the station by Caterpillars. The
cargo had to be loaded on a secure area on the sea ice as ice
conditions did not allow Polarstern to enter the "ice port" right next
to the shelf edge.
The first samples
A Spanish team of scientists seized the opportunity of a small patch of
open water to catch live animals for observation in aquaria. They will
investigate sessile cnidarians living on the seafloor. The main
objective is to find out whether these animals are exclusively feeding
on fresh algae from the summer bloom or can they also utilize other
food sources under conditions of extended periods of sea ice cover.
These findings will be a substantial contribution to answer much
broader questions such as how did communities adapt to the particular
conditions beneath the Larsen Ice Shelves and how do they differ from
"normal" areas. A catch with the Agassiz trawl was bountiful and also
provided sponges, the most distinct group of animals living on the
seafloor in the shelf ecosystem. As the first working groups are
supplied with organisms scientific work is running.
Fish survey
On the way to the Antartic Peninsula where the major scientific work
will be running Polarstern carried out more than 75 thirty-minute
trawls. Length measurements, weight and gender determination, stomach
content analyses and the removal of tiny ear bones for age structure
analyses are done on board. The sum of the scientific data will provide
a comprehensive indication of the fish population dynamics since the
end of Antarctic commercial fishing in 1990. The bottom fish survey
conducted during ANT XXIII/8 is the seventh survey in a row in the
southern Scotia Arc region. The survey contributes to the 'Convention
on the Conservation of Antarctic Marine Living Resources' (CCAMLR).
This organization is responsible for the conservation and rational use
of all Antarctic marine resources with the exception of cetaceans.
Germany focuses its CCAMLR-related research on the state of fish and
krill stocks in the Atlantic sector of the Southern Ocean. This
research is conducted by the Seafisheries Institute of the Federal
Research Centre for Fisheries in Hamburg on behalf of the Federal
Ministry of Nutrition, Agriculture and Consumer's Protection in
cooperation with foreign institutions, such as the Southwest Fisheries
Science Centre of the National Marine Fisheries Service in La Jolla,
USA.
###
Education, Outreach, Communication
Besides their scientifc work Dr Gauthier Chapelle fom the International
Polar Foundation and the chief scientist Dr Julian Gutt are providing
several internet websites with pictures, films, reports and personal
impressions directly from board of Polarstern. If you like to join the
expediton, have a look on the following internet pages:
http://www.polarjahr.de/Expeditionsberichte.38.0.html
http://www.polarfoundation.org/
http://www.cousteau.org/caml.html
http://www.caml.aq/news/
http://www.awi.de/Polar/Polarstern/report-index-d.html
Bremerhaven, 21 December 2006
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