Phenotypic and ecological diversity of freshwater coccoid cyanobacteria from maritime Antarctica and Islands of NW Weddell Sea. II.

2014 ◽  
Vol 4 (1) ◽  
pp. 17-39 ◽  
Author(s):  
Jiří Komárek
Keyword(s):  
Natural Populations ◽  
Weddell Sea ◽  
South Shetland Islands ◽  
Eastern Region ◽  
Maritime Antarctica ◽  
Shetland Islands ◽  
North Eastern ◽  
Modern System ◽  
Freshwater Habitats ◽  
James Ross Island

The article contains the second part of the review of natural populations of coccoid (unicellular, colonial) cyanobacteria from the coastal, maritime Antarctica and the vicinity of Antarctic Peninsula, mainly from its north-eastern region. The samples were collected from several localities with terrestrial and freshwater habitats of the deglaciated parts of South Shetland Islands, and from the northern part of James Ross Island. The material was identified according to the modern system (Komárek et al. 2014b). This second part contains 16 species (from 12 genera) from the cytologically more complicated orders Chroococcales, Pleurocapsales and Chroococcidiopsidales, characterized also by more irregular thylakoidal system. Similarly as in types from the order Synechococcales, all species are connected with special habitats and their cultivation is difficult. They are adapted to the special biotopes and in spite of their relatively wide diversity, only few occurred rarely in massive populations. Several species are evidently endemic for Antarctica, 8 species are described as new recognized taxa.

Phenotypic and ecological diversity of freshwater coccoid cyanobacteria from maritime Antarctica and islands of NW Weddell Sea. I. Synechococcales.

2013 ◽  
Vol 3 (2) ◽  
pp. 130-143 ◽  
Author(s):  
Jiří Komárek
Keyword(s):  
Natural Populations ◽  
Weddell Sea ◽  
South Shetland Islands ◽  
Ecological Diversity ◽  
Maritime Antarctica ◽  
Shetland Islands ◽  
Terrestrial Habitats ◽  
James Ross Island ◽  
Cyanobacterial Diversity

The review of freshwater natural populations of coccoid cyanobacteria from the ecosystems of the coastal Antarctica in the vicinity of Antarctic Peninsula is presented in two consequent articles. The natural cyanobacterial populations were studied from deglaciated regions with aquatic and terrestrial habitats, mainly from the islands Nelson and King George (South Shetland Islands) and from the northern deglaciated part of the James Ross Island (NW part of the Weddell Sea). Majority of identified morphospecies was distinctly ecologically restricted and their cultivation was not successful; the molecular evaluation was therefore not possible. All morphotypes appeared also in small quantities, and only few morphospecies created locally more intense populations. However, the knowledge of phenotype variation is important for the classification of Antarctic cyanobacterial diversity. This first article contains 11 taxa (morphospecies) from 9 genera from the simple phylogenetic clade, classified recently in the order Synechococcales (the second part will contain species from more complicated unicellular cyanobacterial orders). Our results were compared with literary data, but several populations occurred only rarely in atypical stages and their taxonomic classification was difficult. The modern cyanobacterial system (Hoffmann et al. 2005, Komárek et al. 2013) is used for the classification.

Freshwater Cyanobacteria of North-Eastern Australia: 2. Chroococcales

Phytotaxa ◽  
2013 ◽  
Vol 133 (1) ◽  
pp. 1 ◽  
Author(s):  
GLENN B. MCGREGOR
Keyword(s):  
Light Microscopy ◽  
Natural Populations ◽  
Northern Territory ◽  
Detailed Account ◽  
Ecological Data ◽  
Eastern Australia ◽  
North Eastern ◽  
Rivers And Streams ◽  
Original Illustrations ◽  
Freshwater Habitats

This volume provides the first detailed account of the Chroococcales of north-eastern Australia. It provides keys, morphological and ecological data for 6 families, 33 genera and 112 species, and photomicrographs and original illustrations to enable the identification of natural populations based on stable and recognizable characters observable with the aid of light microscopy. Distributional data are based on extensive surveys at 270 sites representing the major freshwater habitats including rivers and streams, palustrine and lacustrine wetlands, thermal springs, and man-made reservoirs in Queensland and the Northern Territory as well as a review of the Australian phycological literature. 

Three new Hantzschia species (Bacillariophyta) from the Maritime Antarctic Region

Phytotaxa ◽  
2018 ◽  
Vol 371 (3) ◽  
pp. 168 ◽  
Author(s):  
MARIE BULÍNOVÁ ◽  
NATALIA KOCHMAN-KĘDZIORA ◽  
KATEŘINA KOPALOVÁ ◽  
BART VAN DE VIJVER
Keyword(s):  
Electron Microscopy ◽  
New Species ◽  
Morphological Analysis ◽  
South Shetland Islands ◽  
Maritime Antarctic ◽  
Antarctic Region ◽  
Shetland Islands ◽  
James Ross Island ◽  
Three New Species ◽  
Scanning Electron

Following an earlier revision of the genus Hantzschia (Bacillariophyta) in the Maritime Antarctic Region, several at present unidentified or poorly known taxa of this aerophilic genus have been investigated using both light and scanning electron microscopy. Based on the morphological analysis of the observations, three new species are currently described: Hantzschia australabundans sp. nov., H. zidarovae sp. nov. and H. zikmundiana sp. nov. The new species differ from comparable taxa in valve outline, structure of the internal proximal raphe endings and structure of the striae and areolae. Additional observations are presented on Hantzschia amphioxys and its forma muelleri, H. abundans and H. incognita, based on observations of Antarctic populations from the South Shetland Islands, Vega Island and James Ross Island. Brief notes on the ecology of all reported species are added.

Ten new Bacillariophyta species from James Ross Island and the South Shetland Islands (Maritime Antarctic Region)

Phytotaxa ◽  
2016 ◽  
Vol 272 (1) ◽  
pp. 37 ◽  
Author(s):  
RALITSA ZIDAROVA ◽  
KATEŘINA KOPALOVÁ ◽  
BART VAN DE VIJVER
Keyword(s):  
New Species ◽  
South Shetland Islands ◽  
Similar Species ◽  
Maritime Antarctic ◽  
The South ◽  
Antarctic Region ◽  
Shetland Islands ◽  
James Ross Island ◽  
The Antarctic

The present paper describes 10 new diatom (Bacillariophyta) species from the Maritime Antarctic Region. Five of the newly described taxa: Caloneis australis sp. nov., Mayamaea sweetloveana sp. nov., Navicula romanedwardii sp. nov., Sellaphora antarctica sp. nov. and Sellaphora gracillima sp. nov. have been previously reported from the Antarctic Region but were force-fitted into incorrect names. Five other taxa: Chamaepinnularia elliptica sp. nov., Cosmioneis regigeorgiensis sp. nov., Mayamaea tytgatiana sp. nov., Muelleria pimpireviana sp. nov. and Pinnularia pinseeliana sp. nov. are newly discovered taxa. The morphology of all new species is studied using both light and scanning electon microscope observations and compared with similar species from the Antarctic Region and worldwide. Data about the ecology and confirmed Antarctic distribution of the new species are added.

scholarly journals Surface mass balance of small glaciers on James Ross Island, north-eastern Antarctic Peninsula, during 2009–2015

2018 ◽  
Vol 64 (245) ◽  
pp. 349-361 ◽  
Author(s):  
ZBYNĚK ENGEL ◽  
KAMIL LÁSKA ◽  
DANIEL NÝVLT ◽  
ZDENĚK STACHOŇ
Keyword(s):  
Mass Balance ◽  
Antarctic Peninsula ◽  
Mass Gain ◽  
Equilibrium Line ◽  
South Shetland Islands ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
North Eastern ◽  
James Ross Island ◽  
The Mean

ABSTRACTTwo small glaciers on James Ross Island, the north-eastern Antarctic Peninsula, experienced surface mass gain between 2009 and 2015 as revealed by field measurements. A positive cumulative surface mass balance of 0.57 ± 0.67 and 0.11 ± 0.37 m w.e. was observed during the 2009–2015 period on Whisky Glacier and Davies Dome, respectively. The results indicate a change from surface mass loss that prevailed in the region during the first decade of the 21st century to predominantly positive surface mass balance after 2009/10. The spatial pattern of annual surface mass-balance distribution implies snow redistribution by wind on both glaciers. The mean equilibrium line altitudes for Whisky Glacier (311 ± 16 m a.s.l.) and Davies Dome (393 ± 18 m a.s.l.) are in accordance with the regional data indicating 200–300 m higher equilibrium line on James Ross and Vega Islands compared with the South Shetland Islands. The mean accumulation-area ratio of 0.68 ± 0.09 and 0.44 ± 0.09 determined for Whisky Glacier and Davies Dome, respectively, is similar to the value reported for Vega Island and within the range of typical values for high-latitude glaciers.

scholarly journals The genus Stauroneis (Bacillariophyta) from the South Shetland Islands and James Ross Island (Antarctica).

Fottea ◽  
2014 ◽  
Vol 14 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Ralitsa Zidarova ◽  
Katerina Kopalova ◽  
Bart Van de Vijver
Keyword(s):  
South Shetland Islands ◽  
The South ◽  
Shetland Islands ◽  
James Ross Island

Surface mass balance of Davies Dome and Whisky Glacier on James Ross Island, north-eastern Antarctic Peninsula, based on different volume-mass conversion approaches

2019 ◽  
Vol 9 (1) ◽  
pp. 1-12
Author(s):  
Zbyněk Engel ◽  
Filip Hrbáček ◽  
Kamil Láska ◽  
Daniel Nývlt ◽  
Zdeněk Stachoň
Keyword(s):  
Mass Balance ◽  
Mass Gain ◽  
Equilibrium Line ◽  
South Shetland Islands ◽  
Surface Mass Balance ◽  
Equilibrium Line Altitude ◽  
Surface Mass ◽  
Shetland Islands ◽  
James Ross Island ◽  
Accumulation Area Ratio

This study presents surface mass balance of two small glaciers on James Ross Island calculated using constant and zonally-variable conversion factors. The density of 500 and 900 kg·m–3 adopted for snow in the accumulation area and ice in the ablation area, respectively, provides lower mass balance values that better fit to the glaciological records from glaciers on Vega Island and South Shetland Islands. The difference between the cumulative surface mass balance values based on constant (1.23 ± 0.44 m w.e.) and zonally-variable density (0.57 ± 0.67 m w.e.) is higher for Whisky Glacier where a total mass gain was observed over the period 2009–2015. The cumulative surface mass balance values are 0.46 ± 0.36 and 0.11 ± 0.37 m w.e. for Davies Dome, which experienced lower mass gain over the same period. The conversion approach does not affect much the spatial distribution of surface mass balance on glaciers, equilibrium line altitude and accumulation-area ratio. The pattern of the surface mass balance is almost identical in the ablation zone and very similar in the accumulation zone, where the constant conversion factor yields higher surface mass balance values. The equilibrium line altitude and accumulation-area ratio determined for the investigated glaciers differ by less than 2m and 0.01, respectively. The annual changes of equilibrium line altitude and the mean values determined over the period 2009–2015 for Whisky Glacier (311 ± 16 m a.s.l.) and Davies Dome (393 ± 18 m a.s.l.) coincide with the values reported from Bahía del Diablo Glacier on Vega Island but differ from the glaciological records on South Shetland Islands.

scholarly journals Natural iron enrichment around the Antarctic Peninsula in the Southern Ocean

2009 ◽  
Vol 6 (4) ◽  
pp. 7481-7515 ◽  
Author(s):  
M. V. Ardelan ◽  
O. Holm-Hansen ◽  
C. D. Hewes ◽  
C. S. Reiss ◽  
N. S. Silva ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Weddell Sea ◽  
South Shetland Islands ◽  
The South ◽  
Total Acid ◽  
Shetland Islands ◽  
Iron Enrichment ◽  
Bransfield Strait ◽  
Natural Iron ◽  
The Antarctic

Abstract. As part of the US-AMLR program that occupied 99 hydrographic stations in the South Shetland Islands-Antarctic Peninsula region in January–February of 2006, concentrations of dissolved iron (DFe) and total acid-leachable iron (TaLFe) were measured in the upper 150 m at 16 stations (both coastal and pelagic waters). The concentrations in the upper mixed layer (UML) of DFe and TaLFe were relatively high in Weddell Sea Shelf Waters (~0.6 nM and 15 nM, respectively) and lowest in Drake Passage waters (~0.2 nM and 0.9 nM, respectively). In the Bransfield Strait, representing a mixture of waters from the Weddell Sea and the Antarctic Circumpolar Current (ACC), concentrations of DFe were ~0.4 nM and of TaLFe ~1.7 nM. The highest concentrations of DFe and TaLFe in the UML were found at shallow coastal stations close to Livingston Island (~1.6 nM and 100 nM, respectively). The ratio of TaLFe:DFe varied with the distance to land: ~45 at the shallow coastal stations, ~15 in the high-salinity waters of Bransfield Strait, and ~4 in ACC waters. Concentrations of DFe increased slightly with depth in the water column, while that of TaLFe did not show any consistent trend with depth. Our data are consistent with the hypothesis that the relatively high rates of primary production known from the central regions of the Scotia Sea are partially sustained by natural iron enrichment resulting from a northeasterly flow of iron-rich coastal waters originating in the South Shetland Islands-Antarctic Peninsula region.

scholarly journals Geographic distribution of epilithic diatoms (Bacillariophyceae) in Antarctic lakes, South Shetland Islands, Maritime Antarctica Region

Check List ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. 797-809
Author(s):  
Juliana Ferreira da Silva ◽  
Maria Angélica Oliveira ◽  
Rodrigo Paidano Alves ◽  
Ana Paula Vestena Cassol ◽  
Raylane Ribeiro da Anunciação ◽  
...  
Keyword(s):  
Optical Microscope ◽  
Water Systems ◽  
South Shetland Islands ◽  
Maritime Antarctica ◽  
Shetland Islands ◽  
Epilithic Diatoms ◽  
Polar Environment ◽  
Low Diversity ◽  
Unique Species ◽  
Antarctic Environment

Organisms adapt to the environment by establishing themselves in suitable locations. Adaptation to the harsh Antarctic environment is no different. In this work the communities of epilithic diatoms in ice-free areas of water systems of five Antarctic islands are studied. The samples were oxidized, and permanent sheets were later prepared for analysis of the material. They were examined using an optical microscope and mounted on stubs for identification of the taxon in an electron microscope. Fifty-nine species distributed in 28 genera were collected. Only four species were observed in all study areas. Deception Island had unique species in comparison with those on other islands. Knowing the diatom community is a first step in understanding the systems that they inhabit. The polar environment is challenging due to the difficulty of sampling and low diversity and abundance.

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