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Wyszukujesz frazę "Węsławski, J. M." wg kryterium: Autor


Wyświetlanie 1-5 z 5
Tytuł:
Ecosystem maturation follows the warming of the Arctic fjords
Autorzy:
Weslawski, J.M.
Buchholz, F.
Gluchowska, M.
Weydmann, A.
Powiązania:
https://bibliotekanauki.pl/articles/48879.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
climate change
biodiversity
ecosystem
maturation
Arctic fjord
Hornsund
Kongsfjorden
physical environment
Opis:
Two fjords in West Spitsbergen (Hornsund 77°N and Kongsfjorden 79°N) differ with regard to their exposure towards increasingly warm Atlantic water inflow. Hornsund remains in many respects cooler than Kongsfjorden (on average 2°C SST in summer) and is less influenced by warmer and more saline Atlantic waters. Reported changes in the physical environment (temperature rise, freshwater inflow, salinity drop, turbidity, fast-ice reduction, coastal change) are discussed in the context of biological observations in the pelagic and benthic realms with special reference to krill (Euphausiacea). We conclude that well-documented changes in the physical environment have had little effect on the fjord biota and that both organisms and their ecological functions in the fjords are well adapted to the scale of ongoing change. The observed changes fit the definition of ecosystem maturation, with greater diversity, a more complex food web and dispersed energy flow at the warmer site.
Źródło:
Oceanologia; 2017, 59, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of bacterial production in the water column between two Arctic fjords, Hornsund and Kongsfjorden (West Spitsbergen)
Autorzy:
Ameryk, A.
Jankowska, K.M.
Kalinowska, A.
Weslawski, J.M.
Powiązania:
https://bibliotekanauki.pl/articles/47914.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
bacterial production
environmental factor
water column
chlorophyll a
water temperature
bacterial biomass
dissolved organic carbon
dissolved organic matter
Arctic fjord
Spitsbergen
Kongsfjorden
Hornsund
Opis:
Bacterial production and the accompanying environmental factors were measured in the water columns of two Arctic fjords during the cruise in July and August 2013. Water samples were collected at six stations located in the central part of Hornsund and Kongsfjorden. In Hornsund, where average water temperatures were 1.25-fold lower than in Kongsfjorden, the bacterial production was twice as high (0.116 ± 0.102 vs 0.05 ± 0.03 mg C m−3 h−1). Statistical analysis indicated that chlorophyll a concentration itself was not a significant factor that affected bacterial production, in contrast to its decomposition product, pheophytin, originating from senescent algal cells or herbivorous activity of zooplankton. Single and multiple regression analysis revealed that water temperature, dissolved organic carbon (DOC), and pheophytin concentration were the main factors affecting bacterial production in both fjords.
Źródło:
Oceanologia; 2017, 59, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entrapment of macroplankton in an Arctic fjord basin, Kongsfjorden, Svalbard
Autorzy:
Weslawski, J.M.
Pedersen, G.
Petersen, S.F.
Porazinski, K.
Powiązania:
https://bibliotekanauki.pl/articles/47968.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
zooplankton
Themisto libellula
Thysanoessa rashii
plankton concentration
Limacina helicina
Arctic fjord
Thysanoessa inermis
macroplankton
krill
Svalbard
Kongsfjorden
Opis:
This paper presents the results of 15 zooplankton tows collected with a Tucker Trawl (1 m2 opening, net of 2 mm mesh size) in Kongsfjorden (79◦N), Svalbard archipelago. The hydroacoustic survey revealed clear differences between the plankton concentrations in the outer and inner fjord basins. Plankton concentrations and fish were observed in the outer fjord, while uniformly scattered objects were detected in the inner basin. The macroplankton community was dominated by Euphausiacea (Thysanoessa inermis, Thysanoessa rashii), Amphipoda (Themisto libellula) and Pteropoda (Limacina helicina). Other taxa were of minor numerical importance. The macroplankton abundance reached 3300 indiv. 100−1 m−3 with a maximum biomass of 100 g wet weight 100−1 m−3 (over 440 kJ 100−1 m−3). L. helicina was advected into the fjord with surface waters, and was found in large abundance (1000 indiv. 100−1 m−3) in the subsurface layers of the inner basin. Euphausids were present in small numbers at the entrance to the fjord, but were found to be very abundant (600 indiv. 100−1 m−3) at the innermost stations, especially in the surface water layer. The estuarine circulation driven by the glacial meltwater discharge is believed to cause the entrapment of zooplankton in the inner fjord basin.
Źródło:
Oceanologia; 2000, 42, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The malacostracan fauna of two Arctic fjords (West Spitsbergen): the diversity and distribution patterns of its pelagic and benthic components
Autorzy:
Legezynska, J.
Wlodarska-Kowalczuk, M.
Gluchowska, M.
Ormanczyk, M.
Kedra, M.
Weslawski, J.M.
Powiązania:
https://bibliotekanauki.pl/articles/48015.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Malacostraca
plankton
glacial fjord
Spitsbergen
Kongsfjorden
Hornsund Region
Atlantic water
diversity
distribution
Opis:
This study examines the performance of pelagic and benthic Malacostraca in two glacial fjords of west Spitsbergen: Kongsfjorden, strongly influenced by warm Atlantic waters, and Hornsund which, because of the strong impact of the cold Sørkapp Current, has more of an Arctic character. The material was collected during 12 summer expeditions organized from 1997 to 2013. In all, 24 pelagic and 116 benthic taxa were recorded, most of them widely distributed Arctic-boreal species. The advection of different water masses from the shelf had a direct impact on the structure of the pelagic Malacostraca communities, resulting in the clear dominance of the sub-arctic hyperiid amphipod Themisto abyssorum in Kongsfjorden and the great abundance of Decapoda larvae in Hornsund. The taxonomic, functional and size compositions of the benthic malacostracan assemblages varied between the two fjords, and also between the glacier-proximate inner bays and the main fjord basins, as a result of the varying dominance patterns of the same assemblage of species. There was a significant drop in species richness in the strongly disturbed glacial bays of both fjords, but only in Hornsund was this accompanied by a significant decrease in density and diversity, probably due to greater isolation and poorer quality of sediment organic matter in its innermost basin. Our results suggest that the diversity and distribution of benthic malacostracans in these two fjords are only distantly related to the different hydrological regimes; rather, they are governed by locally acting factors, such as depth, sediment type, the variety of microhabitats and the availability and quality of food.
Źródło:
Oceanologia; 2017, 59, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Can seabirds modify carbon burial in fjords?
Autorzy:
Weslawski, J.M.
Urbanski, J.
Gluchowska, M.
Grzelak, K.
Kotwicki, L.
Kwasniewski, S.
Legezynska, J.
Wiktor, J.
Wlodarska-Kowalczuk, M.
Zaborska, A.
Zajaczkowski, M.
Stempniewicz, L.
Powiązania:
https://bibliotekanauki.pl/articles/47719.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sea bird
sediment
organic matter
Kongsfjorden
microplankton
carbon source
Svalbard Fjord
Opis:
Two high latitude fjords of Spitsbergen (Hornsund 77°N and Kongsfjorden 79°N) are regarded as being highly productive (70 g and 50 gC m−2 year−1) and having organic-rich sediments. Hornsund has more organic matter in its sediments (8%), nearly half of it of terrestrial origin, while most of that in Kongsfjorden (5%) comes from fresh, marine sources (microplankton). Analysis of the carbon sources in both fjords shows that a major difference is the much larger seabird population in Hornsund-dominated with over 100 thousands pairs of plankton feeding little auks in Hornsund versus 2 thousand pairs in Kongsfjorden, and marine food consumption estimated as 5573 tonnes of carbon in Hornsund, versus 3047 tonnes in Kongsfjorden during one month of chick feeding period. Seabird colonies supply rich ornithogenic tundra (595 tonnes of C, as against only 266 tonnes of C in the Kongsfjorden tundra). No much of the terrestrial carbon, flushed out or wind-blown to the fjord, is consumed on the seabed – a state of affairs that is reflected by the low metabolic activity of bacteria and benthos and the lower benthic biomass in Hornsund than in Kongsfjorden.
Źródło:
Oceanologia; 2017, 59, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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