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The marine Arctic has played an essential role in the history of our planet over the past 130 million years and contributes considerably to the present functioning of Earth and its life. The global cycles of a variety of materials fundamental to atmospheric conditions and thus to life depend to a signifi cant extent on Arctic marine processes (Aargaard et al., 1999). The past decades have seen remarkable changes in key Arctic variables. The decrease of sea-ice extent and sea-ice thickness in the past decade is statistically signifi - cant (Cavalieri et al., 1997; Parkinson et al., 1999; Walsh and Chapman, 2001; Partington et al., 2003; Johannessen et al., 2004). There have also been large changes in the upper and intermediate layers of the ocean, which have environmental implications. For instance, the deep Greenland Sea has continued its decadal trend towards warmer and saltier conditions, with a corresponding decrease in oxygen content, refl ecting the lack of effective local convection and ventilation (Dickson et al., 1996; Boenisch et al., 1997). Changes in temperature and salinity and associated shifts in nutrient distributions will directly affect the marine biota on multiple scales from communities and populations to individuals, consequently altering food-web structures and ecosystem functioning (Benson and Trites, 2002; Moore, 2003; Schumacher et al., 2003; Wiltshire and Manly, 2004; Perry et al., 2005). Today, we do not know whether the severe alterations in abiotic parameters represent perturbations due to human impacts, natural long-term trends, or new equilibriums (Bengtson et al., 2004). Because Arctic organisms are highly adapted to extreme environmental conditions with strong seasonal forcing, the accelerating rate of recent climate change challenges the resilience of Arctic life (Hassol, 2004). The entire system is likely to be severely affected by changing ice and water conditions, varying primary production and food availability to faunal communities, an increase in contaminants, and possibly increased UV irradiance. The stability of a number of Arctic populations and ecosystems is probably not strong enough to withstand the sum of these factors, which might lead to a collapse of subsystems. To detect and track the impact of large-scale environmental changes in the transition zone between the northern North Atlantic and the central Arctic Ocean, and to determine experimentally the factors controlling deep-sea biodiversity, the German Alfred Wegener Institute for Polar and Marine Research (AWI) established the deepsea, long-term observatory HAUSGARTEN, representing the fi rst, and by now only, open-ocean, long-term station in a polar region.

Three main aspects of the possible impacts of retreating pack ice and changing ice coverage in the European Arctic on the higher trophic levels are discussed in this chapter: 1. Seabirds are depending on their colonies on land during the breeding season; the main species, e.g. little auk Alle alle, feed in mixed Polar/ Arctic Water in order to bring back food (polar zooplankton) to their chicks on the nest. In case ice coverage is very low, distance between colony and feeding grounds might become too long for such daily trips, and little auks might have to interrupt breeding and massively leave their colonies before the end of the reproduction cycle (e.g. on Jan Mayen in July 2005). On a longer term, if ice coverage was decreasing too much in future years, the whole Spitzbergen population might be affected, as well as other seabird species feeding mainly at the ice edge. 2. Stocks of large whales were close to depletion in the north-eastern Atlantic due to massive over-exploitation by whaling, and to their separation from the more abundant North Pacific stocks by high ice coverage of both the North-East and North-West Passages. In the frame of our long-term study of the at-sea distribution of seabirds and marine mammals in Arctic seas from 1979 on, resulting in more than 10,000 half-an-hour transect counts, an important increase of the north-eastern Atlantic stocks was detected from 2007 on, the year with lowest ice coverage, mainly for bowhead Balaena mysticus, blue whale Balaenoptera musculus, humpback whale Megaptera novaeangliae and fin whale Balaenoptera physalus. Such a sudden and important increase cannot be attributed to population growth, but to a probable inflow from the more abundant Pacific stocks, the decrease of ice coverage allowing the opening of the Passages. 3. On the other hand, polar bear Ursus maritimus and its prey: pinnipeds - mainly harp seal Pagophilus (Phoca) groenlandica - seem not to show any important decline of their population, with a few local exceptions. Moreover, encountered bears regularly concerned mother with cub(s), which also reflect the good health status of the population. The reason is probably that they are not bound to pack ice as such, but to the Outer Marginal Ice Zone (OMIZ): they are almost absent in the Closed Pack Ice (CPI). They seem to adapt and follow the OMIZ, even when its position is influenced by changes in ice coverage. These data collected on board icebreaking RV Polarstern are discussed in this chapter, in function of changes in ice coverage, in the extent of the main water masses and thus in the position of the ice edge and fronts.

The legal regime of the Arctic maritime areas has long remained on the backburner as far as the creation of multilateral agreements is concerned. The Arctic's inhospitable climate created natural barriers for the activities of man and limited the usefulness of available technology. At present, however, climate change seems to be responsible for a marked heating up, not only of the physical environment of the Arctic, but of the political tensions concerning the exact legal regime to be applied in the region. This Article will examine the present-day legal status of the Arctic. Since almost all territorial claims have been settled in the area, only Arctic water areas will retain our attention. And, within the multitude of possible offshore activities, this Article will focus solely on navigation. Part I discusses the 1982 United Nations Convention on the Law of the Sea, which seems to have finally become a generally accepted legal cornerstone for appreciating the legal status of these waters. Part II considers climate change in the Arctic and Part III elaborates on how this may impact the legal regime of navigation there. Subsequently, Part IV analyzes the vulnerability as well as the adaptive capacity of the 1982 Convention. Finally, Part V suggests how the existing legal system can better meet the new challenges climate change poses for Arctic water expanses.

14 páginas, 8 figuras, 4 tablas., Latitudinal clines in species diversity in limnic and terrestrial habitats have been noted for well over a century and are consistent across many taxonomic groups. However, studies in marine systems over the past 2 to 3 decades have yielded equivocal results. We conducted initial analyses of the MarBEF (EU Network of Excellence for Marine Biodiversity and Ecosystem Function) database to test for trends in local and regional diversity over the latitudinal extent of European continental-shelf waters (36° to 81° N). Soft-sediment benthic macrofauna exhibit little evidence of a latitudinal cline in local (α-) diversity measures. Relationships with water depth were relatively strong and complex. Statistically significant latitudinal trends were small and positive, suggesting a modest increase in diversity with latitude once water-depth covariates were removed. These results are consistent regardless of whether subsets of the database were used, replicates were pooled, or component taxonomical groups were evaluated separately. Local and regional diversity measures were significantly and positively correlated. Scientific cooperation through data-sharing is a powerful tool with which to address fundamental ecological and evolutionary questions relating to large-scale patterns and processes., The authors acknowledge the support of the MarBEF Network of Excellence ‘Marine Biodiversity and Ecosystem Functioning’ which is funded by the Sustainable Development, Global Change and Ecosystems Programme of the European Community’s Sixth Framework Programme (contract no. GOCE-CT-2003-505446). This publication is contribution no. MPS-09014 of MarBEF.

We studied cellular energy allocation (CEA) in three Arctic benthic species (Gammarus setosus (Amphipoda), Onisimus litoralis (Amphipoda), and Liocyma fluctuosa (Bivalvia)) exposed to oil-related compounds. The CEA biomarker measures the energy budget of organisms by biochemically assessing changes in energy available (carbohydrates, protein and lipid content) and the integrated energy consumption (electron transport system activity (ETS) as the cellular aspect of respiration). Energy budget was measured in organisms subjected to water-accommodated fraction (WAF) of crude oil and drill cuttings (DC) to evaluate whether these compounds affect the energy metabolism of the test species. We observed significantly lower CEA values and higher ETS activity in G. setosus subjected to WAF treatment compared to controls (p = 0.03). Higher CEA value and lower cellular respiration were observed in O. litoralis exposed to DC compared to controls (p = 0.02). No difference in the energy budget of L. fluctuosa was observed between the treatments (p = 0.19). Different responses to oil-related compounds between the three test species are likely the result of differences in feeding and burrowing behavior and species-specific sensitivity to petroleum-related compounds.

Belgica, which Adrien de Gerlache used on the first expedition to winter in the Antarctic, was originally a bottlenose whaler named Patria, built in Norway in 1884. She was designed and constructed by Johan Chr. Jakobsen, renowned for his design of polar ships. Patria was sold to Adrien de Gerlache and renamed Belgica in 1896. In 1896-97 she was refitted and equipped in Sandefjord, Norway, for an Antarctic expedition. Nansen and Amundsen met for the first time on Belgica's deck. Late in 1899 Belgica returned to Antwerp after more than two years on an Antarctic expedition. From 1901 to 1904 Belgica returned to bottlenose whaling and, in addition, made a voyage to northeast Greenland to establish depots and build houses for the Baldwin-Ziegler Polar Expedition. In 1905 the Duc d'Orléans chartered her to survey the coast of northeast Greenland, and on her return he bought her. In 1907 and 1909 she sailed on Arctic expeditions led by the Duc d'Orléans and captained by de Gerlache. In 1916 she was sold to Det Norske Kulsyndikat and renamed Isfjord. She became a freighter carrying coal from Longyearbyen to ports in northern Norway. In 1918 she was sold and her new owner converted her into a floating cod-liver oil refinery and fish-processing plant. In 1940 she was impounded by British forces and used as a floating ammunition depot. On 19 May 1940 she was sunk during a German air raid. Her wreck was re-discovered in 1990.

A hindcast simulation of the Arctic and Antarctic sea ice variability during 1955–2001 has been performed with a global, coarse resolution ice–ocean model driven by the National Centers for Environmental Prediction / National Center for Atmospheric Research reanalysis daily surface air temperatures and winds. Both the mean state and variability of the ice packs over the satellite observing period are reasonably well reproduced by the model. Over the 47-year period, the simulated ice area (defined as the total ice-covered oceanic area) in each hemisphere experiences large decadal variability together with a decreasing trend of ~1 % per decade. In the Southern Hemisphere, this trend is mostly caused by an abrupt retreat of the ice cover during the second half of the 1970s and the beginning of the 1980s. The modelled ice volume also exhibits pronounced decadal variability, especially in the Northern Hemisphere. Besides these fluctuations, we detected a downward trend in Arctic ice volume of 1.8 % per decade and an upward trend in Antarctic ice volume of 1.5 % per decade. However, caution must be exercised when interpreting these trends because of the shortness of the simulation and the strong decadal variations. Furthermore, sensitivity experiments have revealed that the trend in Antarctic ice volume is model-dependent.

The ice covering salty or fresh water tends to remain rather thin, even if the air temperature is low for a long time. This is due to the insulating role of the ice cover itself, which slows down the transfer to the atmosphere of the heat produced by the solidification of the water. A simple thermodynamic model is developed to investigate the heat transfer processes associated with ice accretion. It is seen that the ice thickness tends to increase as the square root of the time elapsed and that the temperature profile in the ice layer is approximately linear. The stability of the solution obtained is examined. Finally, the simple model is applied to sea ice in the Arctic and Antarctic. The magnitude of the oceanic heat flux is shown to be partially responsible for the ice cover being generally thicker in the Arctic than in the Antarctic.

Several sections of the thallus of an arctic population of brown macroalga Laminaria saccharina (L.) Lamour, were collected during April-June 1995, in the Kongsfjorden area at Ny-Aålesund, Svalbard and investigated for halogenating activity. Brominating activity was found in the blade only, while iodinating activity occurred in the whole thallus of L. saccharina. The highest activity occurred in the blade, while lower activity was detected in the stipe and holdfast. No evidence for chlorinating activity was found. Halogenating activity, which clearly depends on temperature, showed increasing rates with increasing temperatures between 5 and 35°C.