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EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > AQUATIC ECOSYSTEMS > PLANKTON

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  • This dataset contains vertical profiles of particles in the upper water column (60 m depth) at six sites. A laser optical plankton counter (LOPC) was deployed through a hole in the sea ice, or from the stern of the Aurora Australis, and lowered to 60 m, logging as it was lowered. The LOPC records particles in the size range 100 um to 20 mm, though the small aperture (7 cm x 7 cm) means that the largest particles are probably only sampled rarely. For each site, the data are presented as normalised biomass for a series of equivalent spherical diameters (ESD). ESD is based on measurements of length and width of animals likely to be sampled via the LOPC (i.e. animals that are sampled at the same time with a traditional plankton net). The data were collected on the SIPEX II voyage of the Aurora Australis, from 14/9/2012 to 16/11/2012. Sites were all located in first year pack ice; the ship would nudge up to a floe and then samples of ice, zooplankton, etc. were collected directly by working on the floe. The LOPC was either deployed through a large hole in the pack ice, or it was deployed off the stern of the AA. Method of deployment did not really have an impact on the data collected, it was more a logistical decision based on conditions.

  • In this data set we examined whether eDNA samples can detect similar numbers of species and community compositions as genetic continuous plankton recorder (CPR) samples. On the V4 voyage 2018 from Hobart to Macquarie island, small and large volume eDNA samples as well as genetic CPR samples were collected. All samples were sequenced with a metazoan specific cytochrome c oxidase I marker (folder "2018_08_28 eDNA V4 COI" contains all genetic CPR and small volume eDNA samples, folder "2019_05_08_eDNA_V4_CBR_Repeats_COI" contains some repeated small volume eDNA samples and all large volume eDNA samples (also called CBR samples)). Additionally, all eDNA samples were sequenced using an 18S rRNA marker (folder "2018_09_19 eDNA V4 18s Ramaciotti") to assess overall biodiversity. Each folder contains the raw sequencing data (fastq format) as well as data indexes and readme files. Please contact us if you are planning on using this data (leonie.suter@aad.gov.au). More information about these datasets are contained in the readme files in the dataset.

  • Ozone depletion over Antarctica increases UVB irradiances reaching the Earth's surface in the region. Marine microbes, that support the Antarctic food web and play an integral part in carbon cycling, are damaged by UVB. This research determines Antarctic UV climate, biological responses to UV from the molecular to community level, and combines these elements to predict UV-induced changes in Antarctic marine microbiology. A season of field work was undertaken over November and December 1994 based from Davis Station with the intention of making field measurements of ultraviolet radiation in the fast ice environment, as well as some of the lakes in the Vestfold Hills. Instrumentation The instrument for the measurements was a Macam spectral radiometer, owned by Geography and Environmental Studies, University of Tasmania. Field personnel were Dr Kelvin Michael (IASOS) and Mr Michael Wall (Honours student, Geography and Environmental Studies, UTas). The radiometer was equipped with a 25-metre quartz light pipe, with a cosine sensor attachment at the end. To make a measurement of ultraviolet irradiance, the sensor would be oriented so that its sensing surface was horizontal, and it would collect light which was then transmitted along the light pipe to the radiometer - a suitcase-sized unit which ran on battery power in the field. The radiometer was encased in a wooden box lined with polystyrene foam to provide protection from the elements and heat insulation. The radiometer was controlled via a laptop PC and the data were stored on the hard disk of the PC. Measurements Measurements of the attenuation of ultraviolet and visible radiation as a function of wavelength in water were made at the ice edge and lake measurement sites. At the ice edge, the light pipe was spooled over a wheel and lowered to preset depths (typically 1,2,4,8,16 and 32 m below the water surface). On a lake, a 25-cm augur hole was drilled, and the light pipe was lowered by hand to various depths, the exact depths chosen depended on the depth of the lake. Where the lake ice conditions permitted, a frame was lowered through the hole and used to lever the light pipe against the underside of the ice and a measurement of the ultraviolet and visible transmission of the sea ice was collected. In all cases, measurements of the ultraviolet and visible surface irradiance were collected before and/or after the sub-surface measurements. When the sky conditions were sufficiently clear, the direct and diffuse components of the ultraviolet and visible irradiance values were estimated, via the use of a shading apparatus. This would ensure that the radiometer would measure the diffuse component of the radiation field, allowing the direct component to be estimated by subtraction of the diffuse from the global (unshaded) measurement. On some occasions, the upwelling irradiance from the snow or ice surface was also measured, providing information on the spectral albedo of the surface. At each measurement, spectral irradiance values were generally collected for two spectral ranges: UV-B (280 - 400 nm, in 1-nm steps) and visible (400 - 700 nm, in 5-nm steps). In some cases, the wavelength boundaries were different - eg 280 - 350 nm for the UV-B, or 550 - 680 nm in the visible (corresponding to channel 1 of the NOAA AVHRR sensor). The data were stored by the PC as raw data files. The names of these files are automatically defined from the time on the logging PC as 'hhmmss.dti'. Note that the PC was operating on Australian Eastern Summer Time, 4 hours ahead of DLT. These data files were later read into Excel spreadsheets for manipulation. See the linked report for further information. The measurements are all in units of watts per metre squared per nanometre (Wm^-2 nm_-1) The heading UV-B refers to the fact that the data are collected in the ultraviolet part of the spectrum (280 - 400 nm) The heading AVHRR refers to the fact that the data are collected in the visible part of the spectrum (400 - 700 nm) The fields in this dataset are: UV Radiation Wavelength Depth AVHRR

  • This data set was collected from two minicosm experiments conducted at Davis Station, Antarctica. 1. Variance experiment - 2013/14 summer season 2. Ocean acidification experiment - 2014/15 summer season It includes: - description of methods for all data collection and analyses. - environmental data logged throughout the experiment; nutrients, temperature, light climate. - flow cytometry counts; autotrophic cells, heterotrophic nanoflagellates, and prokaryotes. - FlowCam counts; individual phytoplankton species data. - microscopy counts; individual phytoplankton species data.

  • Metadata record for data from ASAC Project 2300 See the link below for public details on this project. ---- Public Summary from Project---- Antarctic reefs, like their tropical counterparts, harbour a high diversity of animal life. For the first time we will determine how global warming will affect food availability to the animals which comprise the structural components of the reefs. Ultimately, we wish to predict the cascading effect through the community as one component changes. With the confirmation that sponges in Antarctic waters graze on ultraplankton there is now a global overview that sponges are the primary benthic organism that is responsible for linking the pelagic microbial food web to the benthos. Like other shallow water demosponges, sponges in Antarctica are omnivorous sponges that graze nonselectively, consuming both heterotrophic and phototrophic organisms. Retention efficiencies of ultraplankton are similar to other sponges measured using similar techniques from shallow water to the deep sea, the tropics to boreal waters. The large amounts of water processed by these benthic suspension feeders and their diet places these sponges squarely within the functional group of organisms that link the pelagic microbial food web to the benthos. The number of macroinvertebrates that have been shown to side- step the microbial loop and directly utilize the base of the microbial food web as a primary food source is ever growing and currently includes demosponges, ascidians, soft corals, and bivalves. Dense macroinvertebrate communities dominated by demosponges and corals in shallow water have been shown to remove as much as 90% of the ultraplankton from the water that passes over them. The daily fluxes of ultraplankton to these communities ranges from 9 to 1970 mg C day-1 m-2. We conservatively estimate that this single species of sponge, which comprises only a portion of the benthos, mediates a flux of 444 mg mg C day-1 m-2 from the water column, which places it in the range of shallow-water temperate and boreal systems. Furthermore, we found that physical disturbance results in changes in community structure. The subtidal rocky coasts near Casey are similar to many of the exposed rocky coasts of the world that support extensive stands of macroalgae that form a strong positive association with understorey encrusting coralline algae. Loss of canopies of algae on temperate coasts often triggers large and predictable changes to the assemblage of understorey taxa. We observed large negative effects of removing canopies of H. grandifolius on encrusting corallines growing beneath, with such effects consistent with predictions of previous research on tropical and temperate coasts. However, elevating concentrations of nutrients did not greatly reduce the magnitude of the negative effects of canopy removal. Nevertheless, our results suggest that disturbance (removal) to canopies of H. grandifolius has large consequences for those organisms associated with this widely distributed (circumpolar) species of canopy-forming algae. See the full copy of the final report (available for download from the URL given below) for more information. Also included in the download file, are five Excel spreadsheets. The spreadsheets contain the data collected from the transects, quadrats, etc (see the final report for more information). Where possible the spreadsheets have been converted to csv files. The fields in this dataset are: Location depth Species Transect Quadrat Irradiance PAR

  • This metadata record is a 'Parent' metadata record for ASAC project 2720. See the link for the related 'Child' metadata records. The overall objective is to characterise Southern Ocean marine ecosystems, their influence on carbon dioxide exchange with the atmosphere and the deep ocean, and their sensitivity to past and future global change including climate warming, ocean stratification, and ocean acidification from anthropogenic CO2 emissions. In particular we plan to take advantage of naturally-occurring, persistent, zonal variations in Southern Ocean primary production and biomass in the Australian Sector to investigate the effects of iron addition from natural sources, and CO2 addition from anthropogenic sources, on Southern Ocean plankton communities of differing initial structure and composition. SAZ-SENSE is a study of the sensitivity of Sub-Antarctic Zone waters to global change. A 32-day oceanographic voyage onboard Australia's ice-breaker Aurora Australis was undertaken in mid-summer (Jan 17 - Feb. 20) 2007 to examine microbial ecosystem structure and biogeochemical processes in SAZ waters west and east of Tasmania, and also in the Polar Frontal Zone south of the SAZ. The voyage brought together research teams from Australasia, Europe, and North America, and was led by the ACE CRC, CSIRO Marine and Atmospheric Research, and the Australian Antarctic Division. The overall goal is to understand the controls on Sub-Antarctic Zone productivity and carbon cycling, and to assess their sensitivity to climate change. The strategy is to compare low productivity waters west of Tasmania (areas with little phytoplankton) with higher productivity waters to the east, with a focus on the role of iron as a limiting micro-nutrient. The study also seeks to examine the effect of rising CO2 levels on phytoplankton - both via regional intercomparisons and incubation experiments. Available for download from this metadata record are various datasets collected from the voyage: - An image showing a map of the cruise track. - An excel document detailing hourly position checks of the ship. - An excel document detailing the event log for the voyage. - A word document detailing prospective papers produced from the voyage. Finally a link is available for users to access the special volume of publications produced as a result of this voyage.

  • The Ocean Drilling Program (ODP) has been the largest cooperative marine geology program in history. The Australian Antarctic Division contributed to the Australian ODP budget while ODP was drilling in Antarctic or sub-Antarctic waters. Although initially related to ODP Leg 120 on Kerguelen Plateau (1988), the spirit of this project can also extend to Leg 188 (2000). These involvements have been primarily on foraminifera from the Cretaceous and Neogene but have also contributed to understanding of the sediments and changes of environment with time. A lot has been published and further papers are in press or in preparation. Leg 183 involvement was invited and turned down but Pat Quilty was then asked to present one paper on Late Cretaceous benthic foraminifera (published) and to act as external editor for the volume. This work is now almost final and is available on the WWW. Some sample data are available for download at the url below. For complete datasets, see the ODP website. The fields in this dataset are: Sample Accessory Depth (metres below surface) Species Planktonic percentage Barren

  • Data acquisition Samples were collected at the 3 sites at 9 different depths. Depths included the bottom depth as well as 8 samples in the top 200M. 50ml samples were collected from the niskin bottles attached to the CTD. 20ml was filtered through a 0.02 microlitre filter to remove the viruses and larger organisms from the sample. 1ml of this virus free water was then pipetted into individual cryovials. A further 1ml was then taken from the original seawater sample and was then passed through a 0.2 microlitre filter, which retained all the bacteria and algae. The 0.2 microlitre filter was then placed in the cryovial with the 1ml of virus free seawater. Samples were then fixed with glutaraldehyde (5 microlitre, 50% concentration) at hourly intervals for 4 hours. After fixation samples were placed in liquid nitrogen and later stored at -80 degrees C. All samples will be analysed using a flowcytometer. The fields in these datasets are: Date Leg number Latitude Longitude Subsample Depth (m) Bottle Number Viscosity (cP) This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).

  • Surficial bottom sediments collected from Prydz Bay, Antarctica contain three sedimentary facies, four foraminiferal faunas, and two diatom floras. A sandy diamict (Facies Ds) is deposited by iceberg rafting and reworked by currents of the Prydz Bay Cyclonic Gyre. A massive mud (Facies Mm) represents the sediments being supplied to the Bay and could provide a high resolution record of the Quaternary in Antarctica. A carbonate sand (Facies Cs) is a modern cold water carbonate deposited under special conditions on the outer continental shelf. The presence of planktonic flora and fauna, and variations in sedimentological parameters are consistent with the physical oceanographic evidence for a large cyclonic gyre operating in the Bay. The fields in this dataset are: Sight Device Comments Depth (m) Sample Foram Diatom Percentages of Individual species Number of individuals counted. Plankton

  • Antarctic marine diatoms are sensitive to environment change. This project will determine the environmental niches occupied by key diatom species in Antarctic sediments. This will allow climate changes in the past to be interpreted from Holocene sediments and future changes in diatom biogeography to be predicted. Environmental manipulation and competition experiments using diatoms will identify the response of key taxa to environment modification. Understanding the environmental factors governing their distribution and natural variability will provide a basis to interpret palaeo-environment records, and allow predictions how this temperature-sensitive ecosystem will respond to future change. Diatoms for the experiments were collected in 2002 (Aurora Australia, Voyage 1) and 2003 (Aurora Australis, Voyage 1). On each occasion water from the ship's online seawater tap was filtered through a 20 micrometre plankton net for up to one hour into a sample jar. A portion of the sample was preserved in lugol's iodine for later phytoplankton analysis, and the rest of the sample maintained alive in the dark in seawater at a constant low temperature. The live sample is maintained at the AAD for culturing and environment manipulation and competition experiments. Project 2302 Twenty-two water samples were collected from 24/10/02 to 11/11/02, in open seawater between 53 degrees 50 degrees S and 65 degrees 50 degrees S. At each site, the following were recorded from the ship's data logger: latitude, longitude, date, UCT time, local time, water depth, salinity, water temperature, chlorophyll A, UV radiation, and conductivity.