Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 15
items per page: 25 50 75
Sort by:

Abstract

The purpose of this study was to present the current state of avifauna in the vicinity of Polish Polar Station, at Hornsund (SW Spitsbergen). During four seasons (2003-2006) ten bird species were recorded as breeding there. Among them colonial little auk and Arctic tern were most abundant. Six additional species were noted during the breeding season but none of them bred there and their visits in the study plots were a consequence of their nesting nearby study area. Remaining 11 species were recorded during migration. The most pronounced changes over the last 35 years has been a considerable increase in number of barnacle geese exploiting the tundra as their foraging and resting area.
Go to article

Abstract

Chlorophyll α, phytoplankton, suspensions and zooplankton beneath the fast ice have been studied in Spitsbergen fjords (Hornsund, Bellsund, Sassenfjord, Gronfjord and Kongsfjord) in 1982, 1984/85,1987 and 1988. Observations on ice associated Polar cod and wildlife have been collected simultaneously. There were no typical sympagic communities observed at the West Spitsbergen fast ice. Exception was spring 1982 and 1988 when drifting ice from Barents Sea contributed to the fjords fauna. Fast ice on the investigated fjords was poor in adjacent zooplankton (biomass below 0.06 g/m3). Ice phytoplankton reflects the autumn situation and no specific communities of algae have been found. Chlorophyll α amount and organic sedimentation from ice and from the adjacent water were very similar (0.4 to 1.7 mg/m3 chlorophyll and 8 to 10 g d.w./m2/day sedimenling matter). The diet of Polar cod reflected the food items occurrence, Calanus has been the most common food. N o specific concentration of seabirds have been observed at fjords ice.
Go to article

Abstract

The zooplankton community structure was studied in the Svalbard area at three shelf stations: Billefjorden, Kongsfjorden and Hinlopen (Spitsbergen shelf area), and at two open water stations: Ice West and Ice East (north of Spitsbergen, in the Arctic Ocean). Two different plankton nets – WP-2 and WP-3 – were used to collect a size range of zooplankton. The Bray-Curtis similarity analysis showed differences between sampling stations based on total zooplankton abundance, species composition, and comparison of Calanus spp. development. Total abundance was the highest in Kongsfjorden and Hinlopen. The small omnivorous copepod Oithona similis Claus, 1863 was the dominating species at all localities and the Atlantic copepod Calanus finmarchicus (Gunnerus, 1765) was found at all stations. Calanus spp. development was delayed at the ice stations when compared to the shelf stations. Results are discussed in relation to differences in environmental factors among stations.
Go to article

Abstract

Hornsund and Kongsfjorden are two similar-sized Arctic fjords on the West coast of Spitsbergen. They are influenced by cold coastal Arctic water (Hornsund) and warmer Atlantic water (Kongsfjorden). Environmental conditions affect the timing, quantity, spatial distribution (horizontal and vertical) of spring and summer blooms of protists as well as the taxonomic composition of those assemblages. Here, we compile published data and unpublished own measurement from the past two decades to compare the environmental factors and primary production in two fjord systems. Kongsfjorden is characterized by a deeper euphotic zone, higher biomass and greater proportion of autotrophic species. Hornsund seems to obtain more nutrients due to the extensive seabird colonies and exhibits higher turbidity compared to Kongsfjorden. The annual primary production in the analysed fjords ranges from 48 g C m-2 y-1 in Kongsfjorden to 216 g C m-2 y-1 in Hornsund, with a dominant component of microplankton (90%) followed by macrophytes and microphytobenthos.
Go to article

Abstract

Zooplankton was investigated at fixed site in 24 hours in Kongsfjorden, a glacial fjord situated on the west coast of Spitsbergen (Svalbard) (79°N, 12°E), in order to unveil the level of diurnal variability in community composition and abundance. Parallel to zooplankton study water temperature and salinity were measured while information on local tides and winds was obtained from external sources. Observed changes did not exceed the range of variability regarded intrinsic, resulting from the nature of plankton. Because of this low variability we are of the opinion that the data presented can be regarded a valid measure of the natural heterogeneity of zooplankton communities in hydrologically dynamic Arctic coastal waters in summer. The observed changes in zooplankton were primarily induced by the complex dynamics of the fjord’s water masses. In spite of importance of tidal forcing, the variability in zooplankton did not demonstrate similar temporal fluctuations due to modification of the water movement by other irregular forces (local wind). Also, we have not found any indication of diel vertical migration in coastal water in the Arctic under the condition of midnight sun.
Go to article

Abstract

The total numbers and biomass of bacterioplankton in two Arctic glacial fjords off west Spitsbergen were studied. Samples were collected from different water depth layers – from the surface to 80–90 m depth. Total bacterial number (TBN), biomass and morphological structure (shape of bacteria) were determined using the acridine orange direct count method. The highest values of TBN and biomass in the water column were found in Kongsfjorden in the stations adjacent to Kongsbreen Glacier, and the lowest values in the outer part of the Krossfjorden. The local maxima of bacterioplankton were observed in water layers around pycnocline. The morphological structure was similar in all samples – the bacteria were dominated by rods (over 65%), followed by cocci (16–20%) and vibrios (11–15%).
Go to article

Abstract

Fjords of West Spitsbergen are very dynamic in terms of hydrology. Here we tested whether the qualitative analysis of the taxonomic composition of phytoplankton may be useful as a fast method to assess the origin of the waters and whether it can give any additional information to hydrological data. Phytoplankton samples were collected along transects in Hornsund and Kongsfjord. Among total of 109 taxa identified, only 49 were common in both fjords. The assemblages in Hornsund implied that inflow of the cold waters of the Sřrkapp Current had occurred some time before samples collection, while in Kongsfjord the taxonomic composition was typical for the summer and did not show any recent, unusual hydrological phenomenon. Concluding, the method can be useful in the surveys in which hydrological data are collected infrequently.
Go to article

Abstract

Admiralty Bay (King George Island) is an Antarctic Specially Managed Area and one the most thoroughly studied small-scale marine basins in the Southern Ocean. Our study provides new data on the isopod fauna in this glacially affected fjord. Twelve species of isopods were recorded in this basin for the first time. Six of them were found for the first time in the region of the South Shetland Islands. The highest number of species new for Admiralty Bay were found in the families Munnopsidae (4 species) and Munnidae (3 species).
Go to article

Abstract

Thirty-two species of echinoderms from epibenthic sledges, dredges, scuba diving, and other samples (in total: 467 samples and c. 20 000 specimens) from fjords and coastal waters off Spitsbergen were analysed between 1996 and 2014. The most numerous group of echinoderms in the coastal waters off Spitsbergen is brittle stars (78% of the total individuals). The echinoderms do not form any clear assemblages according to depth or distance from glacial sedimentation and substrate. Some species prefer hard bottom (Strongylocentrotus droebachiensis) or water free from glacial suspensions (Ophiopholis aculeata). In contrast to the species listed above, we also found opportunistic species such as the starfish Urasterias lincki and the brittle star Ophiocten sericeum. These two species are distributed quite uniformly, regardless of the environmental factors. The majority of the species prefer a soft bottom below 200 m.
Go to article

Abstract

We describe surface currents in the Porsanger fjord (Porsangerfjorden) located in the European Arctic in the vicinity of the Barents Sea. Our analysis is based on surface current data collected in the summer of 2014 using High Frequency (WERA, Helzel Messtechnik GmbH) radar system. One of our objectives was to separate out the tidal from the nontidal components of the currents and to determine the most important tidal constituents. Tides in the Porsanger fjord are substantial, with tidal range on the order of about 3 m. Tidal analysis attributes to tides about 99% of variance in sea level time series recorded in Honningsvaag. The most important tidal component in sea level data is the M2 component, with amplitude of ∼90 cm. The S2 and N2 constituents (amplitude of ∼20 cm) also play a significant role in the semidiurnal sea level oscillations. The most important diurnal component is K1 with amplitude of about 8 cm. The most important tidal component in analyzed surface currents records is the M2 component. The second most important component is the S2. Our results indicate that in contrast to sea level, only about 10-30% of variance in surface currents can be attributed to tidal currents. This means that about 70-90% of variance is due to wind-induced and geostrophic currents.
Go to article

Abstract

The environments of inlets, coves and lagoons varies widely. Climate warming has lead to retreat of glaciers directly entering the sea. In lagoons this is accompanied by exposure of an uncolonized substratum. Colonization processes in these lagoon appear to describe processes which have previously occurred in bays and fjords of glacial origin in the South Shetlands.
Go to article

Abstract

Intertidal zone of four gravel beaches in Hornsund Fjord (West Spitsbergen) were investigated in order to study macrofaunal distribution and diversity in these poor habitats. A total of 12 macrofaunal taxa were found in the collected material. The most frequent and the most abundant taxon was Lumbricillus sp. (Oligochaeta). The next most numerous group were juvenile Gammarus spp. juv. The fauna included also polychaetes, molluscs and other crustaceans. The diversity measured with Shannon-Weaver index was low and varied from 0 to 1.4. The analysis revealed that there were no statistically important differences in macrofaunal distribution among stations in fjord. However there were significant differences among various tidal mark zones and high patchiness in animals abundance at each station. Also species composition, density and biomass were diversified along the tide level profile.
Go to article

Abstract

The specific activity of natural gamma emitters like actinium (228Ac), bismuth (212Bi, 214Bi), lead (212Pb, 214Pb), potassium (40K), radium (224Ra), thallium (208Tl) and artificial radioisotope caesium (137Cs) was measured in 2005 in the surface layer of marine sediments in the northern Svalbard: Wijdefjorden, Woodfjorden, Vestfjorden and Bockfjorden as well as in the freshwater reservoirs in Andre Land. Nonuniform spatial distribution of these radionuclides was found. Sediment sample from Bockfjorden had the highest specific activities of all natural radionuclides. The specific radioactivity of 137Cs was much lower than specific radioactivities of natural radionuclides but there were differences between investigated locations. The distribution of 137Cs is similar to persistent organic pollutants of the lake sediments in the area.
Go to article

Abstract

Modern hydrology of a typical Arctic fjord (Hornsund, SW Spitsbergen, Sval− bard) was investigated and compared with commonly used in paleoceanography proxies: benthic foraminiferal assemblages and their stable isotope (#2;18O and #2;13C) composition. The benthic foraminifera from Hornsund comprised 45 species and 28 genera. Their spatial variations follow the zonation pattern, resulting from the influence of Atlantic water at the fjord mouth and glacial meltwaters at the fjord head. At the mouth of the fjord, the total number of species and the contribution of agglutinating species were the highest. In the in− ner part of fjord, the foraminiferal faunas were poor in species and individuals, and aggluti− nating species were absent. “Living” (stained) foraminifera were found to be common throughout the short sediment cores (~10 cm long) studied. The stable isotope values of #2;18O and #2;13C were measured on tests of four species: Elphidium excavatum forma clavata, Cassidulina reniforme, Nonionellina labradorica and Cibicides lobatulus. The results con− firmed the importance of species−specific vital effects, particularly in the case of C. loba− tulus. The variability in the isotopic composition measured on different individuals within a single sample are comparable to isotopic composition of the same species test between sam− pling stations. The temperatures and bottom water salinities calculated from #2;18O values in different foraminifera tests mirrored those recorded for bottom waters in the central and outer fjords relatively well. However, in the case of the inner fjord, where winter−cooled bottom waters were present, the calculated values from #2;18O were systematically higher by about 2#3;C. The obtained results imply that particular caution must be taken in interpretation of fjord benthic foraminifera assemblages in high resolution studies and in selection of ma− terial for isotope analyses and their interpretation in cores from inner fjords or silled fjords, where winter−cooled waters may be present.
Go to article

Abstract

The buoyant hypopycnal flow of brackish water and suspended sediment transport and settling were studied in two sub-polar fjords: the glacial Kongsfjörden and the outwash (non-glacial contact) Adventfjörden, Svalbard . The data presented indicates faster water mixing on the tidal flat in comparison to the englacial runoff, which leads to faster horizontal density gradients decreases in the non-glaciated fjord. The fast settling of particles in the narrow zone of the steep slope at the edge of the tidal flat leads to the removal of 25% of the surface suspended sediment. The rapid settling is due to increasing salinity, decreasing velocity, and flocculation of fine particles. The fast settling of suspended particulate matter (SPM) in the tidal flat area causes sediment redeposition and resuspension followed by sediment transport along the bottom with hyperpycnal flows. This leads to grain sorting in the fjord head. In contrast, at the glacier front, SPM is transported farther into the fjord, where tidal pumping and water mixing lead to the removal of 71% of total SPM. The fjords investigated represent two different sedimentological regimes. In the glaciated Kongsfjörden, the buoyant hypopycnal flow of brackish water is the main sediment transporting factor. In the non-glacial Adventfjörden, hyperpycnal flows transport sediment along the bottom.
Go to article

This page uses 'cookies'. Learn more