The lakes and watercourses are habitats for various communities of cyanobacteria and algae, which are among the few primary producers in Antarctica. The amount of nutrients in the mineral-poor Antarctic environment is a limiting factor for the growth of freshwater autotrophs in most cases. In this study, the main aim was to assess the availability of mineral nitrogen for microorganisms in cyanobacterial mats in James Ross Island. The nitrate and ammonium ions in water environment were determined as well as the contents of major elements (C, N, P, S, Na, K, Ca, Mg, Al, Fe, Mn) in cyanobacterial mats. The molar ratios of C:N, C:P and N:P in mats were in focus. The growth of freshwater autotrophs seems not to be limited by the level of nitrogen, according to the content of available mineral nitrogen in water and the biogeochemical stoichiometry of C:N:P. The source of nutrients in the Ulu Peninsula is not obvious. The nitrogen fixation could enhance the nitrogen content in mats, which was observed in some samples containing the Nostoc sp.

The paper presents the results of a study of cyanobacteria and green algae assemblages occurring in various tundra types determined on the basis of mosses and vascular plants and habitat conditions. The research was carried out during summer in the years 2009–2013 on the north sea−coast of Hornsund fjord (West Spitsbergen, Svalbard Archipelago). 58 sites were studied in various tundra types differing in composition of vascular plants, mosses and in trophy and humidity. 141 cyanobacteria and green algae were noted in the research area in total. Cyanobacteria and green algae flora is a significant element of many tundra types and sometimes even dominate there. Despite its importance, it has not been hitherto taken into account in the description and classification of tundra. The aim of the present study was to demonstrate the legitimacy of using phycoflora in supplementing the descriptions of hitherto described tundra and distinguishing new tundra types. Numeric hierarchical−accumulative classification (MVSP 3.1 software) methods were used to analyze the cyanobacterial and algal assemblages and their co−relations with particular tundra types. The analysis determined dominant and distinctive species in the communities in concordance with ecologically diverse types of tundra. The results show the importance of these organisms in the composition of the vegetation of tundra types and their role in the ecosystems of this part of the Arctic.

Filamentous types from the order Oscillatoriales, particularly the species Phormidium autumnale , have widely diverse morphotypes, which dominate in Arctic aquatic microbial mats and wet soils. We cultivated 25 strains of Ph . autumnale from Svalbard and compared them with available strains from surrounding regions. The comparison of strains, based on 16S rDNA and 16S−23S rDNA intergenic spacer sequences, revealed the similarity of strains from Ellesmere Island, the Canadian Arctic and Abisko, Sweden with strains from Svalbard. The rate of colonization of Ph. atumnale from aquatic habitats is relatively high and we suggest geese as a main transmission vector from surrounding lands. Strains of Ph. autumnale were positioned in the phylogenetic tree according to their occurrence in similar habitats. An apparent clustering factor is the duration of availability of water in lakes and long−lasting streams in contrast to rapid and repeated desiccation in soil and on wetted rock in the spray zone of waterfalls. Strains that grow in very cold waters just above the melting point of snow or ice form a distinct genetic group. The strains investigated in this study show morphological similarity in the shape of the trichomes of the studied specimens. Overall, the cell diameter, except for terminal cells, of our strains varied between 3 and 10 μm. Comparison of 16S rDNA sequences of the genus Ph. autumnale with the previously published definition of the species Microcoleus vaginatus revealed the identity of these two species.

This paper describes in detail the phe notypic traits of the newly discovered Leptolyngbya sieminskae sp. n. (Cyanobacteria). The species was found at two islands of the Svalbard archipelago (Spitsbergen and Nordaustlandet) in habitats which differed in humidity, water sources and altitude. The research was conducted at two fjords: on the southern side of Spitsbergen – Hornsund (77 ° N, 015 ° E) and the north−west side of Nordaustlandet – Murchisonfjord (80 ° N, 018 ° E). Although Leptolyngbya sieminskae was found in different latitudes no significant morphological differences were found between the specimens from both sites. The only visible difference is in the thickness of filaments and sheaths.

This article describes the morphological characteristics of the populations of green alga, Tetraspora gelatinosa , growing in the stressful Arctic conditions (77 ° 00’22” N, 015 ° 32’54.33” E). We present the first detailed morphological characteristics of this species from such a high latitude. Populations from both stagnant and flowing waters were studied. Depending on the type of habitat, their mucilaginous colonies (thalli) have different shapes, but the structure, size and the placement of the vegetative cells, akinetes and ameboid forms, as well as the pseudocilia morphology of both populations, were very similar. Literature data on the distribution of T. gelatinosa indicate that it is a cosmopolitan species. Our data are compared with some characteristic features of this species growing in different geographical and climatic zones. No significant differences were found in the morphology of the colonies compared, nor in the location and the inner structure of cells. How − ever, there were slight differences in cell size between the populations from warm and cold zones.

Qualitative and quantitative composition of phytoplankton of the Olaf

Prydz Bay (Indian Ocean, East Antarctica) was determined on the basis of 49 samples collected at 34 sampling stations during the period from the 15th to 24th February 1969. Altogether 59 taxa of algae were identified — among them: 57 taxa of the class Bacillariophyceae, 1 species of the class Chrysophyceae and 1 genus of the class Dinophyceae. Species occurring most frequently and most abundantly in the Olaf Prydz Bay are diatoms: Thalassiothrix antarctica, Chaetoceros criophilus, Nitzschia curta, Rhizosolenia alata. At some stations Chaetoceros dichaeta occurred in great numbers. A decrease in phytoplankton numbers in the areas south of 67 S is associated with the lack of neritic algae among dominant species.

The algal microfossil Bolboforma reticulata Daniels and Spiegler is recorded from the Oligocene-Miocene glacio-marine sediments of King George Island, South Shetland Islands, Antarctica. The record extends the geographic extent of the species to Antarctica.

This work presents the results of a study whose aim was to determine the influence of algal blooms on precipitation of heavy metals. The scope of the study covered culture of a mixed population made up of Scenedesmus and Pseudokirchneriella algae in experimental conditions and initiating a metal biosorption process with the use of culture biomass by administering ions of Zn(II) and Ni(II). The process was controlled by assessing the level of biosorption of metals entered at a one-off basis in the form of Zn(II) and Ni(II) salts or in the form of mixture of both ions, in comparison to the control sample, at different exposure times (2 hours and 24 hours). The presence of metals was determined both in the biomass and in the culture medium. The presented results of the study confirm the effectiveness of Chlorophyta in the process of zinc and nickel biosorption. A phenomenon of competitiveness between the metals was observed when they were administered at the same time.

We report on the photoresponse dependence on the terahertz radiation intensity in ALGaN/GaN HEMTs. We show that the ALGaN/GaN HEMT can be used as a THz detector in CW and in pulsed regime up to radiation intensity of several kW/cm². The dynamic range in the pulsed regime of detection can be more than 2 decades. We observed that the photoresponse of the HEMT could have a compound composition if two independent parts of the transistor are involved in the detection process; this result indicates that a more simple one channel device may be preferable on the detection purpose.

During the spring of 1998 sympagic algae and meiofauna were studied in Ross Bay on the western coast of the Kane Basin between Ellesmere Island and Pim Island (Canada). Ice samples were collected by ice coring and the lowermost 2 cm sections were analysed. The sea-ice flora was composed of 59 taxa and was dominated by Nitzschia frigida, Navicula pelagica, Fragilariopsis oceanica and unidentified flagellates (over 60% of total number). Abundance of algae ranged from 1×109 to 3×109 cells per square meter. Sea-ice meiofauna was composed of Nematoda and Harpacticoida and was strongly dominated by nematodes (99.76%). Total sympagic meiofauna abundance ranged from 37.5×103 to 146.1×103 ind. and biomass from 2.88 to 8.83 mg C per m2. There was no clearly marked patchiness in the horizontal distribution of sympagic algae and meiofauna.

The occurrence of 18 species of algae was stated in the investigated region. Among them the following were predominant: Himantothallus grandifolius, Desmarestia menziesii, Cystosphaera jacqninotii, Ascoseira mirabilis. Leptosomia simplex. Adenocystis utricularis. Monostroma hariotii, Iridaei: obovata, Hildenbrandia lecunnellieri, Plocamium coccineum and Phycodrys antarctica. Vertical stratification of the distribution of three singled out communities of algae was observed downwards to the depth of 90 m, which is the limit of the occurrence of the algae in the Bay. The process of decomposition depends on the place where it occurs, the kind of the thalluses and the season of the year. The quickest decomposition of algae was observed on the shore, in the summer and spring. The total quantity of algal matter washed ashore along 15.8 km of the coast line of Admiralty Bay, during the period between February and October 1979, was estimated at 279 metric tons of dry weight matter. From this quantity, in result of decomposition of the algae on the shore, 75 tons of the matter were released during an average time of 12 days. The remaining 204 tons of partially decomposed algal matter are driven by winds farther inshore or into the waters of the Bay or remain ashore among the stony rubble.

In surface horizons of Gelic Regosols. Gelic Gleysols and Gelic Cambisols from 5 sites in Kaffiöyra. 26 taxa of blue-green algae have been determined. Species of the genera Gleocapsa, Schizothrix, Tolypothrix and Calothix were the most common. In Gelic Regosols blue-green algae formed during the last 100 years the 0.5 cm thick horizon A, containing 8.6% of humus.

The use of phytoplankton as an indicator of water pollution is a promising tool for assessment of water quality. The purpose of this study was to determine whether diversity indices, including the species richness and diversity of phyto-plankton, could be used for reliable assessment of water quality in the Wadaslintang Reservoir in Indonesia. Surveys were conducted monthly at eight sites, from July 2019 to October 2019. Phytoplankton was collected during the day at 10:00 until approximately 15:00 in the euphotic zone. The parameters investigated were species richness and the abundance of phytoplankton, as well as water quality parameters listed in Government Regulation Number 82 of 2001. The level of pol-lution was represented biologically by the Shannon–Wiener diversity index and physicochemically by the STORET (stor-age and retrieval of water quality data) index. Moreover, the two indices were compared to determine whether a particular diversity index was more effective for assessment of this reservoir. The results showed that during the dry season, 22 taxa of phytoplankton were present, belonging to Cyanophyta, Chlorophyta, Chrysophyta, and Euglenophyta. During the wet season, 29 taxa were found, belonging to Cyanophyta, Chlorophyta, and Chrysophyta. Based on the Shannon-Wiener index and STORET index, water quality was better during the wet season than during the dry season. The results of water quality assessment using both indices were consistent, but the diversity index was a more sensitive indicator of pollution levels. Therefore, the Shannon–Wiener index is a useful tool for assessment of water quality in the Wadaslintang Reservoir.

The article presents a novel solution based on dairy wastewater sorption on a biochar substrate obtained through thermal decomposition of Chlorella sp. algae biomass. The algal biomass obtained in the culture medium containing wastewater from dairy production was separated from the culture medium through sedimentation and centrifugation and then freeze-dried. After freeze-drying, the dry biomass was pyrolysed at 600 °C in a CO ₂ atmosphere.The EDS analysis showed that the oxygen-tocarbon (O/C) and nitrogen-to-carbon (N/C) ratios in the obtained material averaged 0.24 and 0.54 respectively. The arrangement and structure of the obtained biochar was evaluated using Raman spectroscopy. The observed spectra revealed the presence of D bands located at 1346–1354 cm ^-1 and corresponding to disordered carbon structures, as well as G bands located at 1585–1594 cm ^-1 and corresponding to tensile vibrations. The D/G intensity ratio was determined at 0.28. The next phase of the research involved sorption of dairy wastewater from cleaning processes containing 1 g of the obtained biochar using solid phase extraction. The study results confirmed high sorption efficiency of the obtained algal biochar. Turbidity was reduced by 93%, suspension by 88%, sulphates by 61%, chlorides by 80%, and organic carbon by 17%. The research confirmed the possibility of using wastewater from dairy production as a natural culture medium for Chlorella sp. algae cultivation to manufacture valuable biochar, which could be used as a sorption bed in the treatment of dairy wastewater from cleaning processes.

There are approximately 15 million users of system heat in Poland, but unfortunately nearly 70% of the fuel used in heat production is fossil fuel. Therefore, the CO2 emission reduction in the heat production industry is becoming one of the key challenges. City Heat Distribution Enterprise Ltd. in Nowy Sącz (Miejskie Przedsiębiorstwo Energetyki Cieplnej sp. z o.o.) has been conducting a self-financed research and development project entitled The use of algae as carbon dioxide absorbers at MPEC Nowy Sącz. The project deals with postcombustion CO2 capture using Chlorella vulgaris algae. As a result of tests conducted in a 1000 l hermetic container under optimal temperature and light conditions, the recovery of biomass can be performed in weekly cycles, yielding approximately 25 kilograms of biomass per year. Assuming that half of the dry mass of the algae is carbon, it can be said that 240 grams of carbon is bound in one cycle, which, converted to CO2, gives 880 grams of this gas. Our results showed that around 45.8 kilograms of CO2 per year was absorbed. Additionally, it is possible to use waste materials and by-products of technological processes as a nutrient medium for algae

At the northern border of pack ice the study on chlorophyll a content, density of cells, species composition and domination in samples from the drifting ice floes and from brash ice was carried out. 102 taxa of algae were found in the pack ice. In the study area algal taxa were rather uniformly distributed. In different ice layers the qualitative composition of diatom assemblages was similar and usually the diatom Nitzschia cylindrus was dominant and most frequent. Chlorophyll a content (from 0.12 to 334.5 mg m-3) and the density of cells (from 0.3 to 362 x l0 6 cm) varied strongly in various habitats. Ice floes near the northern pack ice border contained low values of chlorophyll a (mean value 0.50 ±0.28 mg m-3) . However, brash sea ice originating from ice floes, contained 142.4 ±117.5 mg m-3 of chlorophyll α in visibly discoloured and 30.1 ±24.3 mg m~3 of chlorophyll α in not visibly discoloured parts on average. The range of chlorophyll α content and the presence of characteristic species allow to distinguish brash sea ice infiltration assemblage of diatoms.

Eight samples of the ice algae were collected from the annual ice in Tikhaia Bay, Hooker Island, Franz Josef Land. Species composition included 58 diatoms (and some Navicula, Nitzschia and other Pennatophyceae unidentified species), 2 dinoflagellates, 2 chrysophyceans, 1 chlorophycean, 1 cyanophycean and possible dinoflagellate and chrysophycean cysts. The maximum quantity was 132300 cells/l. In 4 samples Aulacoseira granulatu prevailed, in other samples Nitzschia frigida, N. cylindrus, Rhizoclonium sp. and dinoflagellate cysts dominated. Xanthiopyxis polaris found by Gran (1904) in Arctic sea ice and referred to the diatoms is, possibly, the dinoflagellate cyst. On the whole, the ice community consisted of benthic and planktonic-benthic species of mainly marine and brackishwater-marine pennate diatoms, their resting stages, freshwater unicellular algae and marine chlorophycean.

Chlorophyll a content and the density and species composition of algae were determined in drifting sea ice north of the Elephant Island (between 54-56°W and 60°30'—61°00'S) at the end of October 1986. In yellow-brownish pieces of brash ice the amount of chlorophyll α was on average 203.5 ± 149.9 mg m-3 at the density of algal cells of 255.7+137.8-103 in cm3. In not visibly discoloured ice the respective values were about 80 times lower, and in surface water about 700 times lower. 69 algal taxa were recorded in the samples, almost all of which were diatoms. Nitzschia cylindrus dominated in all the samples. A comparison of species composition in the investigated habitats revealed that the highest species similarities occurred between samples collected in discoloured ice, lower in the uncoloured ice and the lowest ones in water.

Some 20 samples of bottom sediments of freshwater lakes collected in the Antarctic Thala Hills oasis (Enderby Land) were soaked in laboratory cultures. 85 taxa of algae were identified in these cultures: Cyanophyceae — 54, Chrysophyceae — 1, Xanthophyceae 10 and Chlorophyceae — 20 taxa. Most of these taxa are illustrated.

A map was made of the distribution of macroalgae groupings in shallow waters of Admiralty Bay. The map was plotted on the basis of analysis of color reversal air photograph taken from a helicopter. A significant agreement of the results of the pictures analysis with the field studies was found. Also a number of areas not covered by field studies was determined as the ones of probable occurrence of macroalgae. A detailed map of distribution of four distinguished forms of macroalgae groupings was plotted for a small area in the region of Shag Point. Each of these forms is characterised by different association of algal species.

The paper presents descriptions and illustrations of Anthracoporella spectabilis Pia (Dasycladaceae) and Palaeoaplisina laminaeformis Krotov (Hydrozoa) from the Treskelodden Formation (Lower Permian, Sakmarian) of the Hornsund area (Treskelen, Urnetoppen), and Chaetetes arcticus sp. n. (Demospongiae) from the „Wordiekammen Limestone" (Pernio — Carboniferous) of the Isfjorden area of the southern and central part of Spitsbergen. A. spectabilis and P. laminaeformis common in the Hornsund area are also known from the northern Ural Mts. and Timan.

This research analysed the availability of phytoplankton and the growth rate of Vannamei shrimp in relation to water quality changes. The research was carried out in February–March 2021 for a half cycle of shrimp cultivation in two ponds of the Brackish Water Fish Culture Probolinggo Laboratory in Probolinggo, East Java, Indonesia. The research used a descriptive method and included a survey. Sampling was made every two weeks for two months. Nine parameters were measured and ten shrimps were taken for a specific growth rate ( SGR) measurement once per sampling. Data were analysed using the principal component analysis (PCA) and canonical correspondence analysis (CCA). Secondary data of water quality were added for the PCA. The results show that the phytoplankton found in the first pond consisted of Chlorophyta, Chrysophyta, and Cyanophyta, whereas the phytoplankton in the other pond included Chlorophyta, Chrysophyta, Cyanophyta, and Dinophyta. The abundance of phytoplankton ranged from 12–80∙10 ³ cell∙cm ^–3, which indicated eutrophic waters. The PCA demonstrated that pH, nitrate, and total organic matter (TOM) significantly influenced phytoplankton abundance in the pond. In addition, water quality parameters, such as temperature, transparency, salinity, nitrite and phosphate levels, were tolerable in both ponds for the growth of shrimps. However, the level of pH was lower than the aquaculture quality standard, whereas those of nitrate, ammonia, and TOM were higher. The growth rate of Vannamei shrimp increased by 0.76–7.34%∙day ^–1.

It appears from the analysis of the chemical composition of macroalgae of the Antarctic: Adenocystis utricularis and Himantothallus grandifolius (brown algae), Leptosomia simplex (red algae) and Monostroma hariotti (green algae) that the examined algae, brown algae in particular (mainly Adenocystis utricularis), are rich in mineral components, primarily: sodium, potassium, hologens, and structural polysaccharides. Organic substances, such as: proteins, amino acids, lipids, fatty acids, saccharides reduction, chlorophylls and carotenoids, occur in the analysed algae in quantities much smaller in comparison with taxonomically similar macroalgae derived from marine environment having more favourable hydrochemical and climatic conditions.