Biodiversity of freshwater algae and cyanobacteria on deglaciated northern part of James Ross Island, Antarctica. A preliminary study.

Freshwater algae and cyanobacteria have been studied at the James Ross Island (Ant- arctica) since the first Czech expedition to the James Ross Island area in austral summer of 2004. Main emphasis, however, has been devoted to cyanobacteria and diatoms. Therefore, recent knowledge on biodiversity of freshwater species of green algae is fragmentary. The main aim of presented study was to contribute to species list of green algae and cyanobacteria from James Ross Island. To evaluate species richness of algae and cyanobacteria, samples of water/mats from 6 different lakes, shallow ponds, and seepages located in northern deglaciated part of the James Ross Island were collected in austral summers 2012 and 2013, respectively. The samples were analysed using optical microscopy approach after transport to Czech laboratories. Algal and cyanobacterial taxa were determined according to morphological characteristics. Frequencies of individual taxa occurrence in samples were evaluated. Species richness differences between sampling sites was found. Dominating taxa differed between collection sites as well. Altogether, 41 algal and cyanobacterial taxa were found. Some species and genera: Cosmarium sp., Actinotaenium curtum, Staurastrum punctulatum and Chlorobotrys regularis are reported for James Ross Island for the first time. In some samples, there were some species that remained undetermined due to limitations of light microscopy and morphological approach.Byly studovány sladkovodní řasy a sinice ostrova Jamese Rosse, Antarktida. Výsledky analýzy biodiverzity jsou uvedeny podle charakteru stanoviště.Freshwater algae and cyanobacteria have been studied at the James Ross Island (Ant- arctica) since the first Czech expedition to the James Ross Island area in austral summer of 2004. Main emphasis, however, has been devoted to cyanobacteria and diatoms. Therefore, recent knowledge on biodiversity of freshwater species of green algae is fragmentary. The main aim of presented study was to contribute to species list of green algae and cyanobacteria from James Ross Island. To evaluate species richness of algae and cyanobacteria, samples of water/mats from 6 different lakes, shallow ponds, and seepages located in northern deglaciated part of the James Ross Island were collected in austral summers 2012 and 2013, respectively. The samples were analysed using optical microscopy approach after transport to Czech laboratories. Algal and cyanobacterial taxa were determined according to morphological characteristics. Frequencies of individual taxa occurrence in samples were evaluated. Species richness differences between sampling sites was found. Dominating taxa differed between collection sites as well. Altogether, 41 algal and cyanobacterial taxa were found. Some species and genera: Cosmarium sp., Actinotaenium curtum, Staurastrum punctulatum and Chlorobotrys regularis are reported for James Ross Island for the first time. In some samples, there were some species that remained undetermined due to limitations of light microscopy and morphological approach

The genus <i>Nitzschia</i> on the South Shetland Islands and James Ross Island

The purpose of this study was to present LM and SEM observations of Nitzschia taxa encountered on the South Shetland Islands and James Ross Island. During the ongoing taxonomical revision of the freshwater and limno-terrestrial diatom flora on the South Shetland Islands and James Ross Island (Maritime Antarctic Region) eight unknown taxa belonging to the genus Nitzschia were found. These taxa were previously force-fitted into European names such as N. commutata or N. perminuta, but detailed light and scanning electron microscopical observations allowed their separation from the already known taxa and resulted in the description of eight new species. The paper discusses all twelve Nitzschia taxa found in the Maritime Antarctic Region. New taxa are compared to the morphologically most similar taxa and their ecology and biogeography are discussed. Although the genus Nitzschia is present worldwide, a large number of Nitzschia taxa have a restricted distribution within the Antarctic Region, showing a clear bioregionalism

Zeolites from the James Ross Island Volcanic Group basalts, near to Santa Rita Point, James Ross Island, Antarctica

En la isla James Ross, al noreste de la península Antártica, afloran sedimentitas cretácicas y las suprayacen los basaltos del Grupo Volcánico Isla James Ross. Éstos se caracterizan por diferentes coladas emplazadas en ambientes marino subácueo, subglacial, y subaéreo. Las coladas emplazadas en ambiente subácueo originan hialoclastitas. En Punta Santa Rita (64°13’52’’LS y 57°16’10’’LO), situada al sureste de Punta Ekelöf, algunos niveles de basaltos subaéreos poseen estructura amigdaloide, con cavidades de tamaño variable entre 0,3 mm y 1 cm, rellenas con zeolitas y calcita. Los minerales que componen el relleno de las cavidades han sido estudiados con técnicas petrográficas convencionales, microscopía electrónica de barrido, EDS y difracción de rayos x. Todas las zeolitas están enriquecidas en Na. Un intercrecimiento de chabazita-gmelinita, tapiza las paredes de las cavidades, acompañadas por analcima, thomsonita, phillipsita, y calcita hacia el centro, mineral que también se presenta en venillas. El vidrio palagonítico se localiza en las superficies libres y químicamente también está enriquecido en Na, además de Al, K y Ca. Las asociaciones de zeolitas se habrían originado por reacción con aguas superficiales durante el enfriamiento inicial de los flujos de lavas y por recristalización de vidrio. Los basaltos habrían estado expuestos a la acción de fluidos de origen marino, evidenciado por la abundancia de Na hallada en todas las zeolitas y en la palagonita.In the James Ross Island, northeast of the Antarctic Peninsula, Cretaceous sedimentary rocks crop out and they are overlaid by basalts of the James Ross Island Volcanic Group. These basalts are characterized by their different volcanic successions emplaced in subglacial, marine, subaqueous and subaerial environments. Lavas emplaced in subaqueous environment originate hyaloclastite breccia. In Santa Rita Point (64° and 57° 16’10’’W 13’52’’S), located to the southeast of Ekelöf Point, some basalt horizons have amygdaloidal structure with cavities filled with zeolites and calcite, ranging in size between 0.3 mm and 1 cm. The minerals that filled the cavities have been studied with conventional petrographic techniques, SEM, EDS and Xray diffraction. All zeolites are enriched in Na. An intergrowth of chabazite-gmelinite crystals, lining the walls of the cavities, accompanied by analcime, thomsonite, phillipsite, and calcite developed to the center. Calcite also occurs in veins. Palagonite glass is located at the free surfaces and chemically, is also enriched in Na, in addition to Al, K and Ca. Zeolites associations would have been originated by reaction with surface water during the initial cooling of lava flows and / or by recrystallization of glass. The basalts may have been exposed to the action of marine waters, as is evidenced by the abundance of Na in all zeolites and in the palagonitic glass.Fil: Montenegro, Teresita Francis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Basicas, Aplicadas y Ambientales de Buenos Aires; Argentin

First report of Laternula elliptica in the Antarctic intertidal zone

Many Antarctic marine invertebrates are considered to be highly stenothermal, subjected to loss of functionality at increased temperatures and so at high risk of mortality in a rapidly warming environment. The bivalve Laternula elliptica is often used as a model taxon to test these theories. Here, we report the first instance L. elliptica from an intertidal site. Genetic analysis of the tissue confirms the species identity. A total of seven animals ranging in length from 6 to 85 mm were collected from 3 × 0.25 m2 quadrats of intertidal sediments at St Martha Cove on James Ross Island, Eastern Antarctic Peninsula. Ambient temperatures of 7.5 °C within the sediment and 10 °C (air) were recorded. This raises questions as to the current perception that “many Antarctic marine invertebrates cannot adapt to higher temperatures”

Biodiversity of freshwater algae and cyanobacteria on deglaciated northern part of James Ross Island, Antarctica. A preliminary study.

Freshwater algae and cyanobacteria have been studied at the James Ross Island (Ant-arctica) since the first Czech expedition to the James Ross Island area in austral summer of 2004. Main emphasis, however, has been devoted to cyanobacteria and diatoms. Therefore, recent knowledge on biodiversity of freshwater species of green algae is fragmentary. The main aim of presented study was to contribute to species list of green algae and cyanobacteria from James Ross Island. To evaluate species richness of algae and cyanobacteria, samples of water/mats from 6 different lakes, shallow ponds, and seepages located in northern deglaciated part of the James Ross Island were collected in austral summers 2012 and 2013, respectively. The samples were analysed using optical microscopy approach after transport to Czech laboratories. Algal and cyanobacterial taxa were determined according to morphological characteristics. Frequencies of individual taxa occurrence in samples were evaluated. Species richness differences between sampling sites was found. Dominating taxa differed between collection sites as well. Altogether, 41 algal and cyanobacterial taxa were found. Some species and genera: Cosmarium sp., Actinotaenium curtum, Staurastrum punctulatum and Chlorobotrys regularis are reported for James Ross Island for the first time. In some samples, there were some species that remained undetermined due to limitations of light microscopy and morphological approach. We plan to sample those locations of the James Ross Island that have never been investigated before for future studie

Facilities of J. G. Mendel Antarctic station: Technical and technological solutions with a special respect to energy sources

In this paper, we focus on technical facilities and technologies used at the Johann Gregor Mendel station (James Ross Island, Antarctica) with a special respect to energy sources used for running the station. Construction of the station is evaluated from energy demand and energy loss points of view. Detailed description of main energy sources, i.e. wind turbines, solar thermal panels, and diesel generators is given. Water management and combustible solid waste management are described as well. Brief overview of future plans related to energy sources at the Johann Gregor Mendel station including an increase in the exploitation of solar energy from photovoltaic panels is given.V článku jsou popsána technická zařízení antarktické stanice J.G.Mendela s ohledem na využití zdrojů energie: větrné elektrárny, solární panely, fotovoltaické články, diesel agregáty. Pozornost je rovněž věnovány konstrukci stanice z hledika vytápění a optimalizace využití energie.In this paper, we focus on technical facilities and technologies used at the Johann Gregor Mendel station (James Ross Island, Antarctica) with a special respect to energy sources used for running the station. Construction of the station is evaluated from energy demand and energy loss points of view. Detailed description of main energy sources, i.e. wind turbines, solar thermal panels, and diesel generators is given. Water management and combustible solid waste management are described as well. Brief overview of future plans related to energy sources at the Johann Gregor Mendel station including an increase in the exploitation of solar energy from photovoltaic panels is given

Seasonal hydrological and suspended sediment transport dynamics in proglacial streams, James Ross Island, Antarctica

Rapid warming of the Antarctic Peninsula is producing accelerated glacier mass loss and can be expected to have significant impacts on meltwater runoff regimes and proglacial fluvial activity. This study presents analysis of the hydrology and suspended sediment dynamics of two proglacial streams on James Ross Island, Antarctic Peninsula. Mean water discharge during 8 January 2015 to 18 February 2015 reached 0.19 m3 s−1 and 0.06 m3 s−1 for Bohemian Stream and Algal Stream, respectively, equivalent to specific runoff of 76 and 60 mm month−1. The daily discharge regime strongly correlated with air and ground temperatures. The effect of global radiation on proglacial water discharge was found low to negligible. Suspended sediment concentrations of Bohemian Stream were very high (up to 2927 mg L−1) due to aeolian supply and due to the high erodibility of local rocks. Total sediment yield (186 t km−2 yr−1) was high for (nearly) deglaciated catchments, but relatively low in comparison with streams draining more glaciated alpine and arctic catchments. The sediment provenance was mostly local Cretaceous marine and aeolian sediments; volcanic rocks are not an important source for suspended load. High Rb/Sr ratios for some samples suggested chemical weathering. Overall, this monitoring of proglacial hydrological and suspended sediment dynamics contributes to the dearth of such data from Antarctic environments and offers an insight to the nature of the proglacial fluvial activity, which is likely to be in a transient state with ongoing climate change

Summer season variability of dissolved oxygen concentration in Antarctic lakes rich in cyanobaterial mats

Since 2007, limnological investigation of terrestrial lakes has been carried out at James Ross Island, Antarctica. The lakes in scope differ in their size, origin, geomorphological and hydrological characteristics. In several selected lakes, dissolved oxygen is measured repeatedly each summer season in order to quantify lake- and weather-related differences. For this study, typical reresentatives of (i) coastal shalow lakes, and (ii) high-altitude lakes with cyanobacterial mats were chosen. We present data on dissolved oxygen measured in 3 d interval during January 2010. Within this time, water temperature decreased gradually from 13 to 3 degC, as well as dissolved oxygen concentration. It varied within in the range of 12.50-18.0 mg l-1 indicating the values close to saturation and suprasaturation, respectively. Dissolved oxygen concentration showed slightly decreasing trend in a course of time. In majority of cases, the lakes with rich cyanobacterial flora showed higher dissolved oxygen concentrations than Lachman Lake 2 which posses less cyanobacterial mats than other the lakes involved into the study. Due to air temperature decrease, Dulanek lake, a high-altitude lake, froze in the last week of January 2010.Článek se zabývá měřeník koncentrace rozpuštěného kyslíku v několika jezerech severní odledněné části ostrova Jamese Rosse jako odrazu fotosyntetické aktivity autotrofů (řas a sinic) vyskytujících se v těchto jezerech.Since 2007, limnological investigation of terrestrial lakes has been carried out at James Ross Island, Antarctica. The lakes in scope differ in their size, origin, geomorphological and hydrological characteristics. In several selected lakes, dissolved oxygen is measured repeatedly each summer season in order to quantify lake- and weather-related differences. For this study, typical reresentatives of (i) coastal shalow lakes, and (ii) high-altitude lakes with cyanobacterial mats were chosen. We present data on dissolved oxygen measured in 3 d interval during January 2010. Within this time, water temperature decreased gradually from 13 to 3 degC, as well as dissolved oxygen concentration. It varied within in the range of 12.50-18.0 mg l-1 indicating the values close to saturation and suprasaturation, respectively. Dissolved oxygen concentration showed slightly decreasing trend in a course of time. In majority of cases, the lakes with rich cyanobacterial flora showed higher dissolved oxygen concentrations than Lachman Lake 2 which posses less cyanobacterial mats than other the lakes involved into the study. Due to air temperature decrease, Dulanek lake, a high-altitude lake, froze in the last week of January 2010

Vegetation mapping of moss-dominated areas of northern part of James Ross Island (Antarctica) and a suggestion of protective measures

In this study, a GPS method was used to measure moss-dominated vegetation areas located at northern part of James Ross Island. Several small-scale (above 400 m2) areas were selected for the measurements of their shape, total area, boarder line, mean slope, and exposition as well as biodiversity of mosses. The areas of interest were located particularly in neighbourhood of the Big and Small Lachman lakes and northern slopes of Berry Hill mesa. Typically, the mossdominated areas were supplied with melt water from neighbouring snow fields formed in previous austral winter season. Specimens of mosses were collected from each site so that dominating species forming community structure could be evaluated. Individual areas differed in species richness, however, Bryum pseudotriquetrum and Hypnum revolutum dominated most of them. Sanionia uncinata was found at the only one of the investigated areas and might be considered as rare species for James Ross Island. In the paper, shape location and area of moss-dominated spots at James Ross Island is reported and discussed in relation to morphological characteristics of particular sites as well as water availability during austral summer season.Práce přináší výsledky mapování vegetačních oáz severní části ostrova Jamese rosse, Antarktida.In this study, a GPS method was used to measure moss-dominated vegetation areas located at northern part of James Ross Island. Several small-scale (above 400 m2) areas were selected for the measurements of their shape, total area, boarder line, mean slope, and exposition as well as biodiversity of mosses. The areas of interest were located particularly in neighbourhood of the Big and Small Lachman lakes and northern slopes of Berry Hill mesa. Typically, the mossdominated areas were supplied with melt water from neighbouring snow fields formed in previous austral winter season. Specimens of mosses were collected from each site so that dominating species forming community structure could be evaluated. Individual areas differed in species richness, however, Bryum pseudotriquetrum and Hypnum revolutum dominated most of them. Sanionia uncinata was found at the only one of the investigated areas and might be considered as rare species for James Ross Island. In the paper, shape location and area of moss-dominated spots at James Ross Island is reported and discussed in relation to morphological characteristics of particular sites as well as water availability during austral summer season

A latest Cretaceous to earliest Paleogene dinoflagellate cyst zonation of Antarctica, and implications for phytoprovincialism in the high southern latitudes

The thickest uppermost Cretaceous to lowermost Paleogene (Maastrichtian to Danian) sedimentary succession in the world is exposed on southern Seymour Island (65° South) in the James Ross Basin, Antarctic Peninsula. This fossiliferous shallow marine sequence, which spans the Cretaceous–Paleogene boundary, has allowed a high-resolution analysis of well-preserved marine palynomorphs. Previous correlation of Cretaceous–Paleogene marine palynomorph assemblages in the south polar region relied on dinoflagellate cyst biozonations from New Zealand and southern Australia. The age model of the southern Seymour Island succession is refined and placed within the stratigraphical context of the mid to high southern palaeolatitudes. Quantitative palynological analysis of a new 1102 m continuous stratigraphical section comprising the uppermost Snow Hill Island Formation and the López de Bertodano Formation (Marambio Group) across southern Seymour Island was undertaken. We propose the first formal late Maastrichtian to early Danian dinoflagellate cyst zonation scheme for the Antarctic based on this exceptional succession. Two new late Maastrichtian zones, including three subzones, and one new early Danian zone are defined. The oldest beds correlate well with the late Maastrichtian of New Zealand. In a wider context, a new South Polar Province based on Maastrichtian to Danian dinoflagellate cysts is proposed, which excludes most southern South American marine palynofloras. This interpretation is supported by models of ocean currents around Antarctica and implies an unrestricted oceanic connection across Antarctica between southern South America and the Tasman Sea