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  • Krill Ecology - Technical Reports and Systems Guides A series of documents detailing work completed and methods used at the Krill Aquarium located at the Australian Antarctic Division. Technical Report # Title and Author Technical Report 1. 26th January 1994. DAPI Epiflourescence Technique. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 2. 5th March 1995. Bag Culture - Cell Growth Count Protocol. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 3. 12th January 1996. Chemical 'Spiking' of Krill Aquarium Bio-filter T12. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 4. 24th June 1996. Cold Temperature Algal Bag Culture Methodology. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 5. 16th April 1997. Algal Bag Culture - Harvesting Method. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 6. 26th October 1999. Aquarium System Bulk Seawater Collection and Storage. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 7. 11th October 1999. Sodium Hypochlorite Treatment of Algal Bag Culture Filtration Unit. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 8. 18th October 1999. Feeding Krill - Algal Strains, Feeding Rate and Nutritional Values. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 9. 22nd November 1999. Krill Biology Section - Parental Algal Culture Maintenance. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 10. 10th April 2000. Krill Group Databases and Maintaining Daily Data Records. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 11. 11th May 2000. Making Up and Use of Iodine Solution as an Indicator of the Presence of Chlorine in Freshwater. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 12. 1st June 2000. Testing for Harmful Ammonia (NH3) in Aquarium Sea Water. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 13. 12th June 2000. Digitron Digilog 2088T Digital Temperature Logger/Gauge - Operating Instructions and Down-Loading Logged Data Guide. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 14. 27th June 2000. Krill Biology - Marine Science Support Shed Gear Storage. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 15. 15th October 2000. Making up of fe Growth Media Stock Solutions for Parental and Algal Bag Culture Production. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 16. 15th January 2001. Algal Bag Culture - Growth Rate Analysis. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 17. 19th July 2004. Protective Epoxy Coating of Onga Seawater Collection Fire Pump. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 18. 27th October 2004. New Krill Aquarium - Bulk Seawater Collection and Storage Logistics. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 19. 11th March 2005. New Krill Aquarium - Algal Bag Culture Filtration System. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 20. 6th April 2005. New Culture Cabinet Bag to Bag Inoculation Procedure. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 21. 17th June 2005. Agar Bacterial Plate Testing for Krill Algal Culture Stocks. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 22. 29th July 2004. New Algal Culture Cabinet - Bag Culture Setup Methodology. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 23. 24th May 2005. Protocol for Sterilization of Bag Culture Air Supply System. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 24. 30th May 2005. 200 litre tank Algal Batch Culture Setup. Author: P. M. Cramp. Australian Antarctic Division. Technical Report 25. 22nd June 2005. Making Up and Shaping Plastic Bags for Algal Culture. Author: P. M. Cramp. Australian Antarctic Division. Techincal Report 26. 19th December 2005. New Krill Aquarium - Algal Strains, Feeding Rates and Nutritional Values. Author: P. M. Cramp. Australian Antarctic Division.

  • 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 traits, life history characteristics evolve by processes of natural selection, but because they are important determinants of biological fitness they have special evolutionary significance. Concepts of life history, as traditionally applied to brown algae, do not adequately reflect this, and they need to be broadened to include consideration of additional characteristics such as longevity and reproductive span. Life histories can be interpreted as adaptive strategies. Experimental evidence indicates that heteromorphic life histories probably evolved in response to seasonal change. Isomorphic life histories are possible adapted to stale environments, although some may also possess certain features which are adaptations to seasonal change. Life histories that lack an independent gametophyte generation may have evolved through reduction of heteromorphic life histories. It is argued that a significant increase in the longevity of sporophytes may have ben critical for the evolution of life histories lacking a free-living gametophyte, and also for the evolution of oogamy, phenomena which have occurred in several brown algal evolutionary lines. The common absence of asexual reproduction in advanced taxa probably indicates that its accessory ecological role in maintaining population size has become redundant, as well as reflecting the advantage of sexual over asexual reproduction. However, there is good evidence that sexual reproduction has been lost in a few species of brown algae, and the possible mechanisms and adaptive significance of this are discussed. Studies on Durvillaea antarctica on Macquarie Island, in the subantarctic, were conducted throughout the 1984 and in the summers of 1983 and 1985. Thereafter the annual sequence of conceptacle initiation, development, maturation and senescence was examined, using light and electron microscopy. Durvillaea antarctica on Macquarie Island releases mature ova and spermatozooids from February to Ausgust, with early stages of conceptacle development being observed during November, December and January, and senescent conceptacles from September to December. Both intertidal and subtidal forms of Durvillaea antarctica are found on Macquarie Island, the subtidal form lacking air cavities. In the light of mating experiments which resulted in successful cross-fertilisation, the two forms are considered to be conspecific.

  • 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).

  • The actual piece of equipment used was an International Light IL 1700Radiometer equipped with broad band detectors to measure PAR, UV-A and erythemal UV-B. The effects of UV-B radiation on the fatty acid, total lipid and sterol composition and content of three Antarctic marine phytoplankton were examined in a preliminary culture experiment. Exponential growth phase cultures of the diatoms Odontella weissflogii and Chaetoceros simplex and the Haptophyte Phaeocystis antarctica were grown at 2 (plus or minus 1)degrees C and exposed to 16.3 (plus or minus 0.7) W.m-2 photosynthetically active radiation (PAR). UV-irradiated treatments were exposed to constant UV-A (4.39 (plus or minus 0.20) W.m-2) and low (0.37 W.m-2) or high UV-B (1.59 W.m-2). UV-B treatments induced species specific changes in lipid content and composition. The sterol, fatty acid and total lipid content and profiles for O. weissflogii changed little under low UV-B when compared with control conditions (PAR alone), but showed a decrease in the lipid content per cell under high UV-B treatment. In contrast, when P. antarctica was exposed to low UV-B irradiance, storage lipids were reduced and structural lipids increased indicating that low UV-B enhanced cell growth and metabolism. P. antarctica also contained a higher proportion of polyunsaturated fatty acids under low UV-B in comparison with PAR irradiated control cultures. The flagellate life stage of P. antarctica died under high UV-B irradiation. However, exposure of P. antarctica to high UV-B irradiance increased total lipid, triglyceride and free fat. The effect of UV-B irradiances on the lipid content of Antarctic marine phytoplankton is species specific. Changes in ambient UV-B may alter the nutritional quality of food available to higher trophic levels. EXPERIMENTAL All measurements of irradiance were made with an International Light IL 1700 Radiometer equipped with broad band detectors to measure PAR, UV-A and erythemal UV-B [14]. A National Institute of Standards and Technology intercomparison package (NIST Test #534/240436-88) was used to calibrate each light sensor. Unialgal cultures of the diatoms Odontella weissflogii and Chaetoceros simplex were isolated from sea ice collected in Prydz Bay, Antarctica during the 1990/91 austral summer. Phaeocystis antarctica was isolated from Prydz Bay in 1982/83 summer. Cultures of diatoms and Phaeocystis antarctica were maintained in 2 l glass flasks using f/2 growth medium [32] and GP5 medium [33] respectively at a temperature of 2 plus or minus 1 degrees C. Cool white fluorescent lights provided photosynthetically active radiation (PAR) intensity of 17.08 J.m-2.s-1 (84.7 micro E.m-2.s-1), with no UV-B enhancement, on a 12 h light : 12 h dark cycle. Immediately before experimental irradiation, three replicate subsamples of approximately 15 ml were obtained from each parental culture and fixed with Lugols iodine, a known sample volume sedimented, and cells counted over 15 replicate fields using a Labovert inverted microscope. Mean cell concentration and standard deviation were then computed. Each exponential growth phase parental culture was thoroughly mixed and 3 replicate 300 ml Costar polystyrene culture flasks (which completely absorbed wavelengths below 295 nm) established for each light treatment (control, low and high UV exposures). Cultures were irradiated for 24 hours in a 48 hour experimental period (6 h light : 12 h dark : 12 h light : 12 h dark : 6 h light) [14, 23]. Exposures were conducted in a Thermoline controlled environment cabinet at 2 plus or minus 1 degrees C with cool white fluorescent tubes to provide PAR and UV-A (320-400 nm), with UV-B provided by FS20T 12 UV-B Westinghouse sunlamps. PAR and UV-A irradiances were 16.3 plus or minus 0.7 W.m-2 (81.3 plus or minus 3.4 micro E.m-2.s-1) and 4.39 plus or minus 0.20 W.m-2 respectively. The spectral distribution and UV-B irradiance were varied by attenuation with glass filters [5] to provide low (0.37 W.m-2) or high UV-B (1.59 W.m-2). Sensors were each covered by an attenuating glass screen and a single layer of Costar culture flask to measure the experimental irradiances to which the algae were exposed. UV-B irradiances were chosen to reflect less than (74%) and greater than (318%) peak UV-B exposure as measured at an Antarctic coastal site (Casey station, 66 degrees S, [34]). Following irradiation each culture was well mixed and approximately 15 ml was fixed with Lugols Iodine for subsequent estimation of cell concentration (as above). Chlorotic and greatly vesicularised cells were considered to be dead [23]. The remainder of each experimental culture was filtered through Whatman GF/F filters. On completion of filtration, the filters were stored at -20C overnight before extraction of lipids the following day.

  • Collections of 23 macroinvertebrate taxa associated with Durvillaea antarctica holdfasts and 58 invertebrate taxa associated with artificial substrata collectors are described from shallow-water and intertidal habitats at Heard Island. The fauna sampled possessed strong biogeographic affinities with the Kerguelen Island fauna and, to a slightly lesser extent, the fauna recorded at Macquarie Island. The fauna possessed negligible affinity with the Antarctic. Experiments involving the offshore tethering of Durvillaea antarctica holdfasts indicated epifaunal invertebrates rapidly abandoned detached holdfasts, but that the few species surviving after one day can probably survive long periods adrift. The fields in this dataset are: Taxon (species) Distribution Locality Date Control

  • ---- Public Summary from Project ---- Understanding the strength of possible biological feedbacks is crucial to the science of climate change. This project aims to improve our understanding of one such feedback, the biogenic production of dimethylsulphide (DMS) and its impact on atmospheric aerosols. The Antarctic ocean is potentially a major source of DMS-derived aerosols. The project will investigate the coupling between satellite-derived aerosol optical depth, phytoplankton biomass and DMS production in the Antarctic Southern Ocean. From the abstract of the attached paper: We analysed the correlation between zonal mean satellite data on surface chlorophyll (CHL) and aerosol optical depth (AOD), in the Southern Ocean (in 5-degree bands between 50-70 degrees south) for the period 1997-2004), and in sectors of the Eastern Antarctic, Ross and Weddell Seas. Seasonality is moderate to strong in both CHL and AOD signatures throughout the study region. Coherence in the CHL and AOD time series is strong between 50-60 degrees south, however this synchrony is absent south of 60 degrees south. Marked interannual variability in CHL occurs south of 60 degrees south. We find a clear latitudinal difference in the cross-correlation between CHL and AOD, with the AOD peak preceding the CHL bloom by up to six weeks in the sea ice zone (SIZ). This is consistent with the ventilation of dimethysulphide (DMS) from sea-ice during melting, and supports field data that records high levels of sulfur species in sea-ice and surface seawater during ice-melt. The fields in this dataset are: Timeseries Worksheet: Date Mean Chlorophyll (mg CHL/cubic metre) Mean Aerosol Optical Depth (no units) 5 Day mean chlorophyll averages 5 day mean aerosol optical depth averages Correlation Worksheet: n - number lag r - correlation coefficient t - student t statistic Global Worksheet Column A = SeaWiFS filename Counter+1 is a counter to indicate the image number in series Date Mean Chlorophyll (mg CHL/cubic metre) Mean Aerosol Optical Depth (no units) Chlorophyll Standard Deviation Mean Aerosol Optical Depth Standard Deviation Chlorophyll Standard Error Mean Aerosol Optical Depth Standard Error Chlorophyll Count (the number of data 'pixels' in the image - the basic pixel size is 9x9km2) Mean Aerosol Optical Depth (the number of data 'pixels' in the image - the basic pixel size is 9x9km2)

  • This metadata record covers ASAC projects 113, 191 and 625. (ASAC_113, ASAC_191, ASAC_625). The total lipid, fatty acid, sterol and pigment composition of water column particulates collected near the Australian Antarctic Base, Davis Station, were analysed over five summer seasons (1988-93) using capillary GC, GC-MS, TLC-FID and HPLC. Polar lipids were the dominant lipid class. Maximum lipid concentrations usually occurred in samples collected in December and January and corresponded with increased algal biomass. Both lipid profiles and microscopic observations showed significant variation in algal biomass and community structure in the water column during each season and on an interannual basis. During the period of diatom blooms (predominantly Nitzschia species) the dominant sterol and fatty acid were trans-22-dehydrocholesterol and 20:5w3, accompanied by a high 16:1w7 to 16:0 ratio. Very high polyunsaturated fatty acid and total lipid concentrations were associated with diatom blooms in the area. Bacterial markers increased late in all seasons after the summer algal blooms. Long chain C30 sterols also increased during the latter half of all seasons. Fjord samples collected in the area reflected greater biomass and diversity in algal and bacterial makers than coastal sites. Signature lipids for the alga Phaeocystis pouchetii, thought to be a major alga in Antarctic waters, were identified in field samples over the five summer seasons studied. Methods Study site Davis Base is situated on the Vestfold Hills, Antarctica and incorporates numerous lakes and fjords (Fig. 1). Samples of water column particulate matter were collected during five summer seasons (1988-93), 500 meters off-shore from Magnetic Island, situated 5 km NW of Davis. Three other sampling areas were situated in the fjords of the Vestfold hills and include two sites in Ellis Fjord, one midway along Ellis Fjord and one near Ellis Fjord mouth and one sample midway along Long Fjord (Fig. 1). These fjords are protected from the marine environment, but are both marine fjords. Davis Station and Magnetic Island were used for the weekly sample sites. The mouth of Long Fjord, the mouth of Ellis Fjord, midway down Long Fjord, the deep basin in Ellis Fjord, O'Gorman Rocks and Hawker island (ocean side) were used for monthly samples. Field collection There was an initial pilot season in 1988-89, which was followed by two more detailed studies in the summers of 1989-90 and 1990-91. Four samples was also analysed from the 1991-92 and five from the 1992-93 summer seasons. During the initial pilot study at Magnetic Island in the 1988-89 summer, three water column particle samples were taken for lipid analyses. The 1989-90 and 1990-91 summer field seasons incorporated weekly sampling of the water column particulates at Magnetic Island. The phytoplankton in the fjords were studied during the summers of 1989-90 and 1990-91. The three sites that were chosen were all sampled three times in each season. Samples were also collected during the 1989-90 and 1990-91 seasons from the Magnetic Island and Fjord site s for pigment analyses. Three and five samples were collected respectively in the 1991-92 and 1992-93 seasons. Samples were also taken for microscopic analyses. For lipid analyses 30-40 liter water column particulate samples were collected at a depth of 10 m. A Seastar or INFILTREX water sampler was used in situ to filter the water through a 14.2 cm Schleicher and Schuell glass fibre filter over a three to four hour period. All filters used during sampling were preheated in a muffle furnace at 500 degrees C overnight to minimise contamination. For pigment analyses 2 to 4 litres were filtered through glass fibre filters (4.7 cm GF/F, nominal pore size 0.7 micro meters). The samples were frozen at -20 degrees C until extraction.