(Supplement Table 1) Individual measurements of prosome length, dry weight and lipid sacs (length, width, area) in arctic calanoid copepods

We present an accurate, fast, simple and non-destructive photographic method to estimate wax ester and lipid content in single individuals of the calanoid copepod genus Calanus and test this method against gas-chromatographic lipid measurements.

(Table 1) Concentration of organohalogenated compounds in clean and contaminated hair of polar bears (Ursus maritimus) from East Greenland

In this pilot study, we report on levels of persistent organohalogenated contaminants (OHCs) in hair of polar bears (Ursus maritimus) from East Greenland sampled between 1999 and 2001. To our knowledge, this is the first study on the validation of polar bear hair as a non-invasive matrix representative of concentrations and profiles in internal organs and blood plasma. Because of low sample weights (13-140 mg), only major bioaccumulative OHCs were detected above the limit of quantification: five polychlorinated biphenyl (PCB) congeners (CB 99, 138, 153, 170 and 180), one polybrominated diphenyl ether (PBDE) congener (BDE 47), oxychlordane, trans-nonachlor and ß-hexachlorocyclohexane. The PCB profile in hair was similar to that of internal tissues (i.e. adipose, liver, brain and blood), with CB 153 and 180 as the major congeners in all matrices. A gender difference was found for concentrations in hair relative to concentrations in internal tissues. Females (n = 6) were found to display negative correlations, while males (n = 5) showed positive correlations, although p-values were not found significant. These negative correlations in females may reflect seasonal OHC mobilisation from periphery adipose tissue due to, for example, lactation and fasting. The lack of significance in most correlations may be due to small sample sizes and seasonal variability of concentrations in soft tissues. Further research with larger sample weights and sizes is therefore necessary to draw more definitive conclusions on the usefulness of hair for biomonitoring OHCs in polar bears and other fur mammals.

Fish biometry and concentration of volatile siloxanes in liver of Atlantic cod (Gadus morhua) and shorthorn sculpin (Myxocephalus scorpius) sampled during RV Lance cruise COPOL in 2009

The purpose of this study was to investigate presence and potential accumulation of cyclic volatile methyl siloxanes (cVMS) in the Arctic environment. Octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcy-clohexasiloxane (D6) were analyzed in sediment, Zooplankton, Atlantic cod (Gadus morhua), shorthorn sculpin (Myxocephalus scorpius), and bearded seal (Erignathus barbatus) collected from the Svalbard archipelago within the European Arctic in July 2009. Highest levels were found for D5 in fish collected from Adventfjorden, with average concentrations of 176 and 531 ng/g lipid in Atlantic cod and shorthorn sculpin, respectively. Decreasing concentration of D5 in sediment collected away from waste water outlet in Adventfjorden indicates that the local settlement of Longyearbyen is a point source to the local aquatic environment. Median biota sediment accumulation factors (BSAFs) calculated for D5 in Adventfjorden were 2.1 and 1.5 for Atlantic cod and shorthorn sculpin, respectively. Biota concentrations of D5 were lower or below detection limits in remote and sparsely populated regions (Kongsfjorden and Liefdefjorden) compared to Adventfjorden. The levels of cVMS were found to be low or below detection limits in bearded seal blubber and indicate a low risk for cVMS accumulation within mammals. Accumulation of cVMS in fish appears to be influenced by local exposure from human settlements within the Arctic.

(Table 2) Mercury and selenium concentration in the brain stem of wild polar bears (Ursus maritimus), east Greenland

Polar bears (Ursus maritimus) are exposed to high concentrations of mercury because they are apex predators in the Arctic ecosystem. Although mercury is a potent neurotoxic heavy metal, it is not known whether current exposures are of neurotoxicological concern to polar bears. We tested the hypotheses that polar bears accumulate levels of mercury in their brains that exceed the estimated lowest observable adverse effect level (20 µg/g dry wt) for mammalian wildlife and that such exposures are associated with subtle neurological damage, as determined by measuring neurochemical biomarkers previously shown to be disrupted by mercury in other high-trophic wildlife. Brain stem (medulla oblongata) tissues from 82 polar bears subsistence hunted in East Greenland were studied. Despite surprisingly low levels of mercury in the brain stem region (total mercury = 0.36 ± 0.12 µg/g dry wt), a significant negative correlation was measured between N-methyl-D-aspartate (NMDA) receptor levels and both total mercury (r = -0.34, p < 0.01) and methylmercury (r = -0.89, p < 0.05). No relationships were observed among mercury, selenium, and several other neurochemical biomarkers (dopamine-2, gamma-aminobutyric acid type A, muscarinic cholinergic, and nicotinic cholinergic receptors; cholinesterase and monoamine oxidase enzymes). These data show that East Greenland polar bears do not accumulate high levels of mercury in their brain stems. However, decreased levels of NMDA receptors could be one of the most sensitive indicators of mercury's subclinical and early effects.

(Table 1) Lipid and organochlorine content in blood of common eiders (Somateria mollissima) in Svalbard

Female common eiders (Somateria mollissima) starve during the nesting stage and may lose 30-45% of their initial body mass, mostly through lipid mobilization. In this study, the effects of fasting on the blood concentrations of three lipid-soluble organochlorines (OCs: polychlorinated biphenyl [PCB]-153; 1-dichloro-2,2-bis (p-chlorophenyl) ethylene [p,p'-DDE]; and hexachlorobenzene [HCB]) were examined in eiders breeding in the high Arctic. Blood samples were taken from females (n = 47) at day 5 and day 20 of the incubation period. The mean wet weight concentrations of PCB-153 and p,p'-DDE increased strongly between day 5 and day 20 (3.6 and 8.2-fold, respectively), while HCB increased less (1.7-fold). There was a strong negative association between daily increase in PCB-153 and clutch size, and a weaker relationship for p,p'-DDE, suggesting that maternal transfer to the eggs is a significant pathway of elimination of OCs in eiders. Moreover, poor body condition (body mass controlled for body size) late in the incubation period was associated with strong daily increase of both p,p'-DDE and PCB-153, which may suggest that the release of these compounds increases when lipid reserves become depleted. For HCB, the increase was mainly associated with increase in blood lipid concentrations, and weakly to the amount of burned lipids. The causes for the differences between the compounds are, however, poorly understood. Although the absolute levels of OCs in eiders were relatively low, their rapid build-up during incubation is worrying as it coincides with poor body condition and weakened immune systems.

(Table 1) Carbon and lipids at DSDP Hole 61-462

The lipids of a Pliocene and a Cretaceous sample from Site 462 were analyzed to assess their source and diagenetic history. Judging from the distributions of the n-alkanes, n-fatty acids, n-alkylcyclohexanes and molecular markers, they are autochthonous, of marine origin, and deposited under oxic paleoenvironmental conditions of sedimentation. The stereochemistry of the various molecular markers (e.g., triterpanes and steranes) of the Pliocene sample indicates that the lipids are geologically mature. This supports the hypothesis of sediment recycling from older formations by turbidite redistribution into the Nauru Basin

Atmospheric, oceanic and hydrological polar motion excitation mechanisms based on a combination of geometric and gravimetric space observations

The goal of our study is to determine accurate time series of geophysical Earth rotation excitations to learn more about global dynamic processes in the Earth system. For this purpose, we developed an adjustment model which allows to combine precise observations from space geodetic observation systems, such as Satellite Laser Ranging (SLR), Global Navigation Satellite Systems (GNSS), Very Long Baseline Interferometry (VLBI), Doppler Orbit determination and Radiopositioning Integrated on Satellite (DORIS), satellite altimetry and satellite gravimetry in order to separate geophysical excitation mechanisms of Earth rotation. Three polar motion time series are applied to derive the polar motion excitation functions (integral effect). Furthermore we use five time variable gravity field solutions from Gravity Recovery and Climate Experiment (GRACE) to determine not only the integral mass effect but also the oceanic and hydrological mass effects by applying suitable filter techniques and a land-ocean mask. For comparison the integral mass effect is also derived from degree 2 potential coefficients that are estimated from SLR observations. The oceanic mass effect is also determined from sea level anomalies observed by satellite altimetry by reducing the steric sea level anomalies derived from temperature and salinity fields of the oceans. Due to the combination of all geodetic estimated excitations the weaknesses of the individual processing strategies can be reduced and the technique-specific strengths can be accounted for. The formal errors of the adjusted geodetic solutions are smaller than the RMS differences of the geophysical model solutions. The improved excitation time series can be used to improve the geophysical modeling.

(Tables 1,2) Tracking records and space use statistics of polar bears (Ursus maritimus) in Storfjorden, Svalbard

Arctic sea ice is declining rapidly, making it vital to understand the importance of different types of sea ice for ice-dependent species such as polar bears Ursus maritimus. In this study we used GPS telemetry (25 polar bear tracks obtained in Svalbard, Norway, during spring) and high-resolution synthetic aperture radar (SAR) sea-ice data to investigate fine-scale space use by female polar bears. Space use patterns differed according to reproductive state; females with cubs of the year (COYs) had smaller home ranges and used fast-ice areas more frequently than lone females. First-passage time (FPT) analysis revealed that females with COYs displayed significantly longer FPTs near (<10 km) glacier fronts than in other fast-ice areas; lone females also increased their FPTs in such areas, but they also frequently used drifting pack ice. These results clearly demonstrate the importance of fast-ice areas, in particular close to glacier fronts, especially for females with COYs. Access to abundant and predictable prey (ringed seal pups), energy conservation and reluctance to cross large open water areas are possible reasons for the observed patterns. However, glacier fronts are retracting in Svalbard, and declines in land-fast ice have been notable over the past decade. The eventual disappearance of these important habitats might become critical for the survival of polar bear cubs in Svalbard and other regions with similar habitat characteristics. Given the relatively small size of many fast-ice areas in Svalbard, the results observed in this study would not have been revealed using less accurate location data or lower-resolution sea-ice data.

Stable carbon isotopic composition of biomarker lipids of DSDP Hole 31-302

The middle Paleocene through early Eocene long-term gradual warming was superimposed by several transient warming events, such as the Paleocene-Eocene Thermal Maximum (PETM) and Eocene Thermal Maximum 2 (ETM2). Both events show evidence for extreme global warming associated with a major injection of carbon into the ocean-atmosphere system, but the mechanisms of carbon injection and many aspects of the environmental response are still poorly understood. In this study, we analyzed the concentration and stable carbon isotopic (d13C) composition of several sulfur-bound biomarkers derived from marine photoautotrophs, deposited in the Arctic Ocean at ~85°N, during ETM2. The presence of sulfur-bound biomarkers across this event points toward high primary productivity and anoxic bottom water conditions. The previously reported presence of isorenieratene derivatives indicates euxinic conditions in the photic zone, likely caused by a combination of enhanced primary productivity and salinity stratification. The negative carbon isotope excursion measured at the onset of ETM2 for several biomarkers, ranges between 3 per mil and 4.5 per mil, much larger than the ~1.4 per mil recorded in marine carbonates elsewhere, suggesting substantial enhanced isotopic fractionation by the primary producers likely due to a significant rise in pCO2. In the absence of biogenic carbonates in the ETM2 section of our core we use coeval planktonic d13C from elsewhere to estimate surface water d13C in the Arctic Ocean and then apply the relation between isotopic fractionation and pCO2, originally calibrated for haptophyte alkenones, to three selected organic biomarkers (i.e., S-bound phytane, C35 hopane, and a C25 highly branched isoprenoid). This yields pCO2 values potentially in the range of four times preindustrial levels. However, these estimates are uncertain because of a lack of knowledge on the importance of pCO2 on photosynthetic isotopic fractionation.