FORAMINIFERAL MG/CA PALEOTEMPERATURE PROXIES IN HIGH LATITUDES
11. QUANTIFICATION OF HIGHER TROPHIC LEVELS
Charlotte De Grave, Laurent Raty
Laboratory for Ecotoxicology and Polar Ecology, Brussels Objectives
This work’s objective was to quantify the at-sea distribution of seabirds and marine mammals in the Greenland Sea, as a function of the main water masses (Atlantic water, polar water, pack ice), identified on the base of hydrological parameters (water temperature, salinity), and of front structures between water masses and the ice edge.
Work at sea
During the ARK-XXI/1b cruise leg, transect counts of seabirds and marine mammals were realized from the bridge of the RV Polarstern while the ship was steaming.
(Counting while the ship is moving minimizes the interactions between the ship and the birds; at stations, the ship can attract seabirds from an unknown range.) A total of 605 half-hour counts were realized. Two counts by helicopter were also realized near the ice edge, on 4 and 10 September 2005; these two counts concerned mainly mammals.
Preliminary Results
The most numerous encountered seabirds were Fulmar, Kittiwake, Little Auk, Ivory Gull and Brünnich’s Guillemot (the latter was however absent from the ice edge west of the Fram Strait, although this might have been due to the rather late date at which we visited this area). Other seabirds present in significant numbers included Ross’s Gull, Glaucous Gull, Arctic Tern, Black Guillemot, Puffin, and Arctic, Pomarine, Long-tailed and Great Skua. Two Gyrfalcons (of the Greenland white morph) were also observed in the pack ice, one on the Yermak Plateau, and the other near Greenland.
Clear structures in the distribution of birds and seals appeared along the 78°50’N transect, along the way to and from the Yermak Plateau, and along the way from Greenland to the Håkon Mosby Mud Volcano (i.e., each time we crossed the ice edge). The distributions of selected species along the 78°50’N transect are presented as graphs at the end of this report. In the pack ice itself, the most numerous species was Ivory Gull; this species disappeared away from the ice (see Fig. 11.1).
Concentrations of seals (mainly Harp and Hooded) occurred in the outer marginal ice zone (OMIZ), where polar bears were also encountered (see Fig. 11.2). Ross’s Gulls occurred near the ice edge and (in small numbers), in the pack ice itself (see Fig.
11.3). Large numbers of feeding Little Auks were present in the OMIZ on the way from Greenland to the Håkon Mosby Mud Volcano, but were not detected near the other ice edges that we crossed (along the 78°50’N transect, they occurred mainly in the central part of Farm Strait – see Fig.11.4). Fulmars and Kittiwakes occurred mainly in open waters, though a few were also present in the pack ice (see Fig. 11.5 and 11.6).
Small groups of dolphins, both white-beaked and white-sided, were seen around Svalbard, and another group of 3 white-sided was observed off the Norwegian coast, while steaming back to Germany. Pods of Minke and Fin Whales were seen on several occasions, principally around Svalbard, along the eastern portion of the 78°50’N transect and further north, near the Yermak Plateau. Along the transect, eight baleen whales were also seen at a longitude more or less comparable to that where a huge feeding ground had been observed further south, during the first leg of the cruise, but no very large concentrations could be detected. A sperm whale could be observed while we were leaving Svalbard for the second part of the cruise leg.
Lastly, a pod of 7 Northern Bottlenose Whales was seen at 75°31'N at 1°38'W, south-west of the Greenland pack ice. In the same general area, a very probable Blue Whale was also observed.
The number of animals obtained during these counts (raw data) will be converted into densities by using conversion factors depending on the conspicuousness of each species, and by taking into account the distance covered by the ship during each count. The density data will then be expressed as daily food intake and placed into an ecological perspective, taking into account the hydrological parameters that were recorded during the counts. They will also be compared to other similar counts that have already been performed in the Arctic, since 1973, as part of a long-term study concerning Polar regions.
Unexpected observations: at least two Sooty Shearwater, a southern hemisphere breeding species that winters in the northern oceans, and that usually does not occur north of Iceland, were observed near Svalbard (this species had also been detected on two occasions during the first cruise leg).
On two occasions, more southern land birds (a Lesser Whitethroat and a Turtle Dove) were found on the ship. Both birds were juveniles; they were probably reverse migrants (birds migrating in a direction opposite to their normal migration path).
Distribution of selected species along the 78°50’N transect (number of individuals observed per half-hour count as a function of longitude) are displayed in figures 11.1 to 11.6.
ARK-XXI/1B
Nb observed / 30 min
Ivory Gull
Nb observed / 30 min
Ross's Gull
Nb observed / 30 min
Little Auk
Nb observed / 30 min
Kittiwake
Nb observed / 30 min
Fulmar
Fig. 11.1: Ivory Gull Fig. 11.2: Seals (Harp and Hooded), and Polar Bear
Fig. 11.3: Ross’s Gull Fig. 11.4: Little Auk
Fig. 11.5: Kittiwake Fig .11.6: Fulmar
INSTITUTES
Adresse /Address
AWI Alfred-Wegener-Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft
Postfach 12 01 61
27515 Bremerhaven / Germany
DWD Deutscher Wetterdienst Hamburg
Abteilung Seeschifffahrt Bernhard-Nocht Str. 76 20359 Hamburg / Germany HeliTransair HeliTransair GmbH
Am Flugplatz
63329 Egelsbach / Germany
Laeisz Reederei F. Laeisz (Bremerhaven) GmbH Brückenstrasse 25
27568 Bremerhaven / Germany
UAB Institute of Environmental Science and Technology (ICTA)
Edifici Ciències, Torre C5 Parells, Planta 4 Autonomous University of Barcelona
08193 Cerdanyola del Vallès (Barcelona) / Spain University Ancona University of Ancona
Dept. of Marine Science
Polytechnic University of Marcus (MARHE) Via Brecce Biancue
60121 Ancona / Italy University Bergen University of Bergen
P.O. Box 7800
N-5020 Bergen / Norway University Geneva University of Geneva,
Department of Zoology 154, route de Malagnou
1224 - Chêvne-Bougeries /Switzerland
VUB Laboratory for Ecotoxicology and Polar Ecology Free University of Brussels (VUB)
Pleinlaan 2, B-1050 Brussels / Belgium
13. FAHRTTEILNEHMER / PARTICIPANTS
Name / Name
Vorname First name
Institut Institute
Beruf/
Profession
Bardenhagen Janine AWI Geologist
Bauerfeind Eduard AWI Oceanographer
Bergmann Melanie AWI Biologist
Beszczynska-Möller Agnieszka AWI Oceanographer
Büchner Jürgen HeliTransair Pilot
Corella Juan Pablo AWI Student
Cornelius Nils NOC . Student
Damm Ellen AWI Geologist
Dannheim Jennifer AWI Biologist
de Grave Charlotte VUB Student
Fahrbach Eberhard AWI Chief Scientist
Falck Eva University Bergen Scientist
Feseker Thomas AWI Geologist
Fuhs Elisabeth HeliTransair Inspector
Graupner Rainer Optimare Technician
Greil Florian AWI Student
Hans Kerstin AWI Student
Hayek Wolfgang AWI Student
Heckmann Hans Hilmar HeliTransair Pilot
Helmke Elisabeth AWI Biologist
Kanzog Corinna AWI Technician
Kolar Ingrid AWI Student
Krauß Nikolas AWI Student
Lemke Peter AWI Chief Scientist
Lensch Norbert AWI Technician
Lichte Ellen AWI CTA
Longet David University Geneva Student
Ludwichowski Kai-Uwe AWI Engineer
Magagnini Mirko
Martinez Botí Miguel Angél UAB Student
Martinez Garcia Alfredo UAB Student
Monsees Matthias Optimare Technician
Müller Daniel AWI Student
Nauels Alexander AWI Student
Pawlowski Jan University Geneva Biologist
Pusceddu Antonio Uni Ancona Scientist
Raty Laurent VUB Biologist
Rudolf Anton HeliTransair Pilot
Sablotny Burkhard AWI Engineer
Schewe Ingo AWI Biologist
Schütt Ekkehard AWI Technician
Schwarz Jill AWI Scientist
Sonnabend Hartmut DWD Technician
Stimac Mihael HeliTransair Inspector
Strüfing Reinhard DWD Meteorologist
Vöge Ingrid AWI CTA
Vogel Ines AWI Technician
Volkenandt Mareike AWI Student
Wegner Jan AWI Meteorologist
Wisotzki Andreas AWI Oceanographer
Wolff Marthi AWI Technician