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Microalgal Biodiversity at Antarctica
A collection of about 20 isolates of Antarctic microalgae from the Windmill Islands region, around Casey Station has been established in the University of Malaya Algae Culture Collection (UMACC). The Antarctic microalgae in the collection includes Chlamydomonas, Chlorella, Stichococcus, Navicula. Ulothrix and Chlorosarcina. Comparative studies on the effect of global warming and UVR stress on these Antarctic microalgae and the tropical collection are being conducted. From the abstract of one of the referenced papers: The growth, biochemical composition and fatty acid profiles of six Antarctic microalgae cultured at different temperatures, ranging from 4, 6, 9, 14, 20 to 30 degrees C, were compared. The algae were isolated from seawater, freshwater, soil and snow samples collected during our recent expeditions to Casey, Antarctica, and are currently deposited in the University of Malaya Algae Culture Collection (UMACC). The algae chosen for the study were Chlamydomonas UMACC 229, Chlorella UMACC 234, Chlorella UMACC 237, Klebsormidium UMACC 227, Navicula UMAC 231 and Stichococcus UMACC 238. All the isolates could grow at temperatures up to 20 degrees C; three isolates, namely Navicula UMACC 231 and the two Chlorella isolates (UMACC 234 and UMACC 237) grew even at 30 degrees C. Both Chlorella UMACC 234 and Stichococcus UMAC 238 had broad optimal temperatures for growth, ranging from 6 to 20 degrees C (growth rate = 0.19 - 0.22 per day) and 4 to 14 degrees C (growth rate = 0.13 - 0.16 per day), respectively. In constrast, optimal growth temperatures for Navicula UMACC 231 and Chlamydomonas UMACC 229 were 4 degrees C (growth rate = 0.34 per day) and 6 to 9 degrees C (growth rate = 0.39 - 0.40 per day), respectively. The protein content of the Antarctic algae was markedly affected by culture temperature. All except Navicula UMACC 231 and Stichococcus UMACC contained higher amount of proteins when grown at low temperatures (6-9 degrees C). The percentage of PUFA, especially 20:5 in Navicula UMACC 231 decreased with increasing culture temperature. However, the percentages of unsaturated fatty acids did not show consistent trend with culture temperature for the other algae studied. There are three spreadsheets available in the download file. ASAC_2590 - provides detail about where each species of algae was collected from. ASAC_2590a - provides data from Teoh Ming-Li et al (2004) ASAC_2590b - provides data from Wong Chiew-Yen et al (2004) The fields in this dataset are: Isolate Culture Collection number Origin (Location) Fatty acids saturated fatty acids polyunsaturated fatty acids monounsaturated fatty acids Temperature growth rate PAR UVB
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Photosynthetic rates of Antarctic sea-ice algae
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From the abstract of one of the papers: Oxygen microelectrodes were used to measure the photosynthetic rates of Antarctic fast ice algal mats. Using the oxygen flux across the diffusive boundary layer below the fast ice at Davis, a productivity range of 0-1.78mg C per square metre per hour was measured. This is at the lower end of fast ice productivity estimates and suggests that conventional carbon 14 techniques may overestimate sea ice algal mat productivity. Photosynthetic capacity (P max) approached 0.05 mg per C.(mg chlorophyl a) per hr. Onset of photosynthesis saturation, E k, was found at about 14 micromol photons per square metre per second. The irradiance of photoinhibition onset, E inh, was about 20 micromol photons per square metre per second and the irradiance at the compensation point, E c, was 4 micromol photons per square metre per second.
Role of micronutrients in the sea ice microbial ecosystem
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The productivity of Antarctic waters may be controlled by the amount of iron. Experiments have shown that this is probably the case for phytoplankton but as yet we do not know if iron limits the growth of sea ice algae. This study will assess whether iron limits sea ice algae production and will conduct experiments to work out how these algae use iron. Measurements have been made to determine whether sea ice algae are limited by Fe. Sea ice samples were taken and this spreadsheet refers to those ice cores Columns A-G are self explanatory Column G is the depth in the ice core from the bottom Column H is the chlorophyll concentration in mg Chl m-2 Column I is the phaeophytin concentration in mg m-2 J is the total amount of protein in the sample ng m-2 K is the total amount of the protein flavodoxin ng m-2 L is the total amount of ferrodoxin ng m-2 These last two enable the Fe limitation status to calculated (not completed).
Macroalgae and seagrass biomass and diversity across the Pilbara Region in November 2013 and May 2014
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As part of the Pilbara Marine Conservation Partnership (PMCP), coral reef surveys of reef macroalgae species (including seagrasses) were undertaken between northern Ningaloo and the Dampier Archipelago. This dataset contains biomass estimates (g DW m-2 and g WW m-2) of macrophytes collected in shallow reef areas in the Pilbara region during two sampling trips: November 2013 and May 2014. Surveys were undertaken using using SCUBA at depths between 2-13m, with macroalgae and seagrasses identified to the lowest possible taxonomic level. The data include: * Macroalgae and seagrass diversity (0.25 square metre quadrats) * Macroalgae and seagrass species composition and biomass per quadrat (0.25 square metre) These data were collected to estimate macrophyte biomass in shallow reef areas across the Pilbara region in two contrasting seasons. These data are an output of the Pilbara Marine Conservation Partnership (PMCP) Coral Reef Health Theme.
Biology of Antarctic Algae
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Metadata record for data from ASAC Project 102 See the link below for public details on this project. From the abstracts of some of the referenced papers: Six species of marine microalgae, namely Phaeodactylum tricornutum Bohlin, Dunaliella tertiolecta Butcher, Isochrysis galbana Parke, Porphyridium purpureum (Bory) Ross, Chroomonas sp., and Oscillatoria woronichinii Anis., have been examined with respect to their gas exchange characteristics and the inorganic carbon species taken up by the cells from the bulk medium. All species showed a high affinity, in photosynthesis, for inorganic carbon and low CO2 compensation concentrations. Such data are suggestive of operation of a 'CO2-concentrating mechanism' in these microalgae. Direct measurements of internal organic carbon pools in four of the species studied confirm this (O. woronichinii and Chroomonas were not tested). By comparison of achieved photosynthetic rates with calculated rates of CO2 supply from the dehydration of bicarbonate, it was shown that Phaeodactylum, Porphyridium and Dunaliella could utilise the bicarbonate present in the medium. Data for the other species were inconclusive although the pH dependence of K 1/2CO2 for photosynthesis by Oscillatoria indicated that this species too could utilise bicarbonate. Such observations could, however, not be used as evidence that, at least in the eucaryotic algae examined, bicarbonate was the inorganic carbon species crossing the plasmalemma as Phaeodactylum, Porphyridium and Dunaliella, and Isochrysis all showed the presence of carbonic anhydrase activity in intact cells as well as in crude extracts. 'External' carbonic anhydrase activity represented from 1/4 to 1/2 of the total activity in the cells of these algae. It is concluded that, as a consequence of a CO2-concentrating mechanism, photorespiration was suppressed in the marine microalgae examined although the data obtained did not allow any firm conclusions to be drawn regarding the species of inorganic carbon transported into the cell. Analysis of the age composition of a given species within a community is fundamental to any study of population dynamics and to the subsequent analyses of community interactions such as competition, succession and productivity. A problem exists in that calendar age often provides little information on the role played by any given individual plant within a population. For many populations the most useful definition of population structure is obtained from an analysis of both the functional age and the vitality of the component plants. Data from such studies on populations of marine macroalgae are lacking mainly because of the lack of suitable methods. This paper provides a review of the methods which have ben applied to such analyses in both terrestrial and marine communities, discusses these methods in the context of marine algae and presents the results of a case study on the analysis of population structure in the large brown alga Durvillaea potatorum. Evidence is presented for the occurrence of sexual reproduction including plasmogamy and meiosis, events previously undescribed in the life history of Ascoseira mirabilis. Ascoseira is monoecious. Gametangia are formed in chains within conceptacles. Synaptonemal complexes, structures concerned with chromosome pairing in meiosis, have been observed in the nucleus of gametangial initials. Mature male and female gametes have the same size and appearance, and resemble typical brown algal zoids. Sexual interaction begins after the female gamete settles down, and both zygotes and unfused gametes develop into sporophytes. It is concluded that Ascoseira has the same basic pattern of life history that characterises the order Fucales, and it is argued that this is probably the result of convergent evolution rather than being indicative of close phylogenetic relationship. Life histories are of central importance in understanding evolution and phylogeny of brown algae. Like other hereditary
Shallow Coastal Marine Fauna of the Vestfold Hills and Rauer Island Antarctica
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This dataset is a description of the shallow coastal marine fauna found in the Vestfold Hills and Rauer Island area, Antarctica. The results are from various surveys in this region over a 12 month period in 1981-82, and a full listing of species (with photographs) is given in the documentation. It includes benthic, pelagic and planktonic organisms of the coast as well as those that inhabit the ice-water interface.
Spring Phytoplankton Assemblages in the Southern Ocean Between Australia and Antarctica
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This dataset comprises of an excel spreadsheet of data collected on the CLIVAR-SR3 cruise in November to December 2001. The spreadsheet contains plankton and carbon data. From the abstract of the referenced publication: Variations of phytoplankton assemblages were studied in November-December 2001, in surface waters of the Southern Ocean along a transect between the Sub-Antarctic Zone (SAZ) and the Seasonal Ice Zone (SIZ; 46.9-64.9 degrees S; 142-143 degrees E; CLIVAR-SR3 cruise). Two regions had characteristic but different phytoplankton assemblages. Nanoflagellates (less than 20 microns) and pico-plankton (~2 microns) occurred in similar concentrations along the transect, but were dominant in the SAZ, Sub-Antarctic Front (SAF), Polar Front Zone (PFZ) and the Inter-Polar Front Zone (IPFZ), (46.9-56.9 degrees S). Along the entire transect their average cell numbers in the upper 70 m of water column, varied from 300,000 to 1,100,000 cells per litre. Larger cells (greater than 20 microns), diatoms and dinoflagellates, were more abundant in the Antarctic Zone-South (AZ-S) and the SIZ (60.9-64.9 degrees S). In AZ-S and SIZ diatoms ranged between 270,000 and 1,200,000 cells per litre, dinoflagellates from 31,000 to 102,000 cells per litre. A diatom bloom was in progress in the AZ-S showing a peak of 1,800,000 cells per litre. Diatoms were dominated by Pseudo-nitzschia spp., Fragilariopsis spp., and Chaetoceros spp. Pseudo-nitzschia spp. outnumbered other diatoms in the AZ-S. Fragilariopsis spp. were most numerous in the SIZ. Dinoflagellates contained autotrophs (eg Prorocentrum) and heterotrophs (Gyrodinium/Gymnodinium, Protoperidinium). Diatoms and dinoflagellates contributed most to the cellular carbon: 11-25 and 17-124 micrograms of carbon per litre, respectively. Small cells dominated in the northern region characterised by the lowest N-uptake and new production of the transect. Larger diatom cells were prevalent in the southern area with higher values of N-uptake and new production. Diatom and nanoflagellate cellular carbon contents were highly correlated with one another, with primary production, and productivity related parameters. They contributed up to 75% to the total autotrophic C biomass. Diatom carbon content was significantly correlated to nitrate uptake and particle export, but not to ammonium uptake, while flagellate carbon was well correlated to ammonium uptake, but not to export. Diatoms have contributed highly to particle export along the latitudinal transect, while flagellates played a minor role in the export. This work was completed as part of ASAC project 1343 (ASAC_1343). The fields in this dataset are: Station (depth, position, date, comments) Species Cells per millilitre cell carbon - micrograms per litre