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This study provides the first documentation of polar bear (Ursus maritimus) maternity denning in snowdrifts around icebergs frozen into the fast ice or grounded on the seafloor. Based on six den observations in north and northeast Greenland during spring surveys in 2018 and 2019 (109 flight hours), together with observations of 20 adult females with 35 cubs of the year (COYs) in adjacent sea ice, we hypothesize that the use of snowdrifts around icebergs for maternity denning is an established behavior in the region and not a random event. Factors influencing maternity denning in snowdrifts around icebergs may include limited suitable drifts on the nearby terrestrial polar desert due to low precipitation, the presence of suitable wind-blown snow banks regardless of the direction of autumn storm winds, cold and stable habitat throughout the winter denning period, and access to ringed seal (Pusa hispida) pupping habitat in the nearby Northeast Water polynya. This type of maternity denning habitat is only available in glaciated regions of the Arctic where marine-terminating glaciers deposit mélange large enough to become grounded offshore and remain in place for months or years. This habitat may become less stable or disappear with long-term climate warming. [ABSTRACT FROM AUTHOR]

Abstract: The hydrography of the Laptev Sea is significantly influenced by river water and sea-ice processes, which are highly variable over the annual cycle. Despite of an estuarine structure the inner and outer shelf regions are decoupled at times as documented by the stability of a warm intermediate layer formed during summer below the Lena River plume. We demonstrate that a remnant of this warm layer is preserved below the fast ice until the end of winter, while only slightly farther to the north, offshore of the landfast ice in the polynya region, the pycnocline is eroded and no signature of this layer is found. The warm intermediate layer (WIL) formed during summer can be used as tracer for Laptev Sea shelf waters throughout the winter. Thereby, residence times of southern Laptev Sea waters can be estimated to be at least from summer to the end of winter/spring of the following year. [Copyright &y& Elsevier]

Samples of the bottom layer (4 cm) of fast ice and under-ice water were collected in May 1997 from the Adventfjorden (Spitsbergen). Concentrations of particulate organic matter (POM) in the bottom layer of the fast ice and under-ice water were similar (about 5.5 mg l -1 ). However, the content of POM in total particulate matter (TPM) was significantly higher (p < 0.001) in ice (25%) than in water (16%). Algal biomass expressed as chlorophyll a within ice was 2.97 μg l -1 melt ice in comparison with 1.33 μg l -1 in under-ice water. Based on algal pigment determination we found that algal communities in the bottom of the fast ice were composed of the following taxonomic groups: diatoms (68.1%), chlorophytes (20.1%), prasinophytes (10.4%) and cryptophytes (1.4%), whereas under-ice water was dominated by diatoms (56.6%), chlorophytes (31.1%) and prasinophytes (12.3%). The ratio of diatoms and chlorophytes to chlorophyll a signal differed significantly between the two environments. Chlorophyllide a was the most abundant degradation product of chlorophyll a . [ABSTRACT FROM AUTHOR]