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EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > SEGMENTED WORMS (ANNELIDS)

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  • Live O. orensanzi were found in the AAD's Marine Research Facility emerging from sediments during feeding on 3 July 2014. It is likely that live specimens were included in samples collected for another species, Antarctonemertes sp. from intertidal rocky areas at Beall Island near Casey station (66 30.4265 degree S, 110 45.851 degrees E), East Antarctica in January and February 2014. It is also possible that the O. orensanzi were collected from southeast Newcomb Bay, adjacent to Casey station on 2 and 3 of February 2012 (Figure 4), and survived in the Marine Research Facility's aquarium, but this is considered less likely. Experiments were conducted at the AAD's quarantine facility in Kingston, Tasmania, between 19 July and 2 September 2014. This metadata record contains the results from bioassays conducted to show the response of Antarctic Polychaetes Ophryotrocha orensanzi to contamination from combinations if IFO 180 fuel and the fuel dispersants Ardrox 6129, Slickgone LTSW and Slickgone NS. Test solutions were prepared following the methods of Singer et al. (2000) with modifications by Barron and Ka'aihue (2003) and others. Water accommodated fractions of fuel in water (WAF) were produced using a 1:25 (v/v) fuel to FSW ratio in accordance with studies by Payne et al. (2014) and Brown et al., (2016) to facilitate comparability of results. Chemically enhanced water accommodated fractions (CEWAF) were made following a lower 1:100 (v/v) fuel to FSW ratio. A 1:20 (v/v) dispersant to fuel ratio was used for all three dispersants, an application rate of 1:20 dispersant to fuel rate was used both because this is the standard default application rate used in the field and to increase comparability to previous studies. Dispersant only mixes were made according to CEWAF specifications, substituting FSW for fuel. Test mixes were prepared in dark temperature-controlled cabinets at 0 plus or minus 1 degree C. Mixes were made in two L or five L glass aspirator bottles using a magnetic stirrer. Mix preparation followed the pre-vortex method in which a 20 - 25 % vortex was achieved in 0 plus or minus 1 degree C FSW before addition of the test materials. Once added, fuel was allowed to cool for a further 10 minutes before subsequent addition of dispersants during CEWAF preparation. Mixes were stirred for a total of 42 h with an additional settling time of 6 h following the recommendations determined as part of the hydrocarbon chemistry component of this project (Kotzakoulakis, unpublished data). The mixture was subsequently serially diluted to achieve the desired concentrations. Test concentrations were 100%, 50%, 20% and 10% for WAF and 10%, 5%, 1% and 0.1% for CEWAF. Concentrations for dispersant only treatments mimicked CEWAF in order to be directly comparable. Test solutions were kept in sealed glass bottles with minimal headspace at 0 plus or minus 1 degree C for a maximum of 3 h before use. Test dilutions were remade each four day period to replenish hydrocarbons lost through evaporation and absorption to simulate a repeated pulse exposure to the contaminant. Ninety percent of the test solution volume was replaced for each beaker during each water change by gently tipping out the solution with minimal disturbance to the test organisms. Replacement solutions were chilled to the correct temperature and replenished immediately to avoid any temperature shock to test animals. Beakers were topped up with deionized water between water changes to maintain water quality and solution volume. Bioassays were conducted in cold temperature cabinets at 0 plus or minus 1 degree C and light regimes were set to 18 h light and 6 h dark to mimic Antarctic conditions used by Brown et al. (2017). Exposure vessels were 100 ml glass beakers containing 80 ml of test solution. Beakers were left open to allow for the evaporation of lighter fuel components. Each experiment consisted of four replicates per treatment concentration, with eight to 10 individuals per replicate (8 each for Slickgone NS, 10 each for Ardrox and LTSW). Experiments ran for 12 days with observations at 24 h, 48 h, 96 h, 7 d, 8 d, 10 d and 12 d. Mortality was assessed at each observation using a Leica MZ7.5 dissecting microscope. Mortality was determined by the absence of response to stimuli, specifically lack of movement in the maxillae or mandibles. No food was added during experiments to avoid inclusion of an additional exposure pathway. Aliquots of each test concentration were taken at the beginning and end of each experiment, as well as before and after each water change to analyse the total petroleum hydrocarbon (TPH) content. Duplicate 25 ml samples were taken for each test dilution and immediately extracted with a mixture of Dichloromethane spiked with an internal standard of BrC20 (1-bromoeicosane) and cyclooctane. Extractions were analysed using Gas Chromatography with Flame Ionisation Detection (GC-FID) and Gas Chromatography mass spectrometry (GC-MS). The measured concentrations were integrated following the methods of Payne et al. (2014) to obtain a profile of hydrocarbon content over each 12 d test period.

  • Depth related changes in the composition of infaunal invertebrate communities were investigated at two sites in the Windmill Islands around Casey station, East Antarctica, during the 2006/07 summer. Sediment cores (10cm deep x 10cm diameter) were collected from 4 depths (7m, 11m, 17, and 22m) from each of three transects at two sites (McGrady Cove and O'Brien Bay 1). Cores were sieved through a 500 micron mesh and extracted fauna were preserved in 8% formalin and were later counted and identified to species or to morphospecies established through previous infaunal research at Casey. This work was conducted as part of ASAC 2201 (ASAC_2201).

  • Metadata record for data from ASAC Project 1229 See the link below for public details on this project. ---- Public Summary from Project ---- This project will develop a method to monitor human impacts in the shallow marine environment of Antarctica. Artificial substratum units, placed at polluted and unpolluted sites, will be recovered after a specific time interval and resident animal communities will be compared to identify the type and magnitude of impacts. Data are community abundance data from artificial substrate units comprised of three nylon mesh pot scourers. Taxa are identified to morphospecies. Substrates were deployed in nearshore waters of Casey Station. Standard deployment was 1 year at 14m depth. Four main sites were used - Brown Bay, Newcombe Bay, O'Brien Bay and Browning Peninsula. Brown Bay is a known contaminated site. Experiments were designed to investigate natural variation on spatial and temporal scales, habitat area and potential impacts of a contaminated site, Brown Bay.

  • Our aim was to compare water and sediment as sources of environmental DNA (eDNA) to better characterise Antarctic benthic communities and further develop practical approaches for DNA-based biodiversity assessment in remote environments. We used a cytochrome c oxidase subunit I (COI) metabarcoding approach to characterise metazoan communities in 26 nearshore sites across 12 locations (including Ellis Fjord, Warriner Channel, Hawker Channel, Abatus Bay, Powell Point, Shirokaya Bay, and Weddell Arm) in the Vestfold Hills (East Antarctica) based on DNA extracted from either sediment cores or filtered seawater. We detected a total of 99 metazoan species from 12 phyla (including nematodes, cnidaria, echinoderms, chordates, arthropods, annelids, rotifers and molluscs) across 26 sites, with similar numbers of species detected in sediment and water eDNA samples. Please cite: Clarke LJ et al. (2021). Environmental DNA metabarcoding for monitoring metazoan biodiversity in Antarctic nearshore ecosystems. PeerJ, DOI: 10.7717/peerj.12458 This work was completed as part of the Davis Aerodrome Project (DAP).

  • Infaunal marine invertebrates were collected from inside and outside of patches of white bacterial mats from several sites in the Windmill Islands, Antarctica, around Casey station during the 2006-07 summer. Samples were collected from McGrady Cove inner and outer, the tide gauge near the Casey wharf, Stevenson's Cove and Brown Bay inner. Sediment cores of 10cm depth and 5cm diameter were collected by divers using a PVC corer from inside (4 cores) and outside (4 cores) each bacterial patch. The size of each patch varied from site to site. Cores were sieved at 500 microns and the extracted fauna preserved in 4 percent neutral buffered formalin. All fauna were counted and identified to species where possible or assigned to morphospecies based on previous infaunal sampling around Casey. An excel spreadsheet is available for download at the URL given below. The spreadsheet does not represent the complete dataset, and is only the bacterial mat infauna data. Regarding the infauna dataset: - in - in the mat or patch of bacteria and out is in the "normal" sediment surrounding the patch without evidence of any bacterial mat presence. - Patch numbers were allocated to ensure there was no confusion between patches in the same area. - Fauna names are our identification codes for each species. Some we have confirmed identifications for, some not. Species names, where we have them and as we get them, are listed against these codes in the Casey marine soft-sediment fauna identification guide. This work was completed as part of ASAC 2201 (ASAC_2201).

  • SAZ photos of sediment trap samples Sediment traps are cones which intercept and store falling marine particles in collection cups. The particles consist of a range of material including phytoplankton, zooplankton, faecal pellets, and dust. Each trap collects a time series of samples. The sediment traps are from deep moorings in the Southern Ocean, typically at 47S, 54S, and 61S and at around 140 degrees East. Each mooring typically has 2-3 traps between 800m and 3800m below sea-level. The samples are size fractionated into less than 1mm and greater than 1mm fractions using a 1mm sieve. Various chemical analyses and observations have been made on the less than 1mm fraction. These are photos are of greater than 1mm fraction, mainly showing 'swimmers.' Photos are mostly taken on the sieve, so the grid is 1mm for scale. Sample identification is in the file name, and also in a label in the photo. The file name format is: Typical example s02_54_800_04.jpg 1) s02: s is for SAZ. Collection season number is first year of collection season. So s02 is from SAZ 2002-2003. 2) 54: Nominal latitude. 3) 800: Nominal depth, m. 4) 04: Cup number, typically 1-21 or 1-13, single digit numbers padded with a zero to help operating systems display files in order. 5) .jpg: All photos are in jpeg format Some files have additional information at end, examples below: * FP: faecal pellet * begin and end: beginning and end of sieving process. Mostly to show faecal pellets at start that are rinsed through sieve. This work was completed as part of ASAC project 1156 (ASAC_1156). See also the metadata record 'Subantarctic Zone (SAZ) Sediment Trap Moorings' (SAZOTS).

  • Metadata record for data from ASAC Project 2691 See the link below for public details on this project. Contaminants may persist in marine sediments and be re-suspended during storms or by the activity of animals. This project will assess the impact of contaminated sediments on plants and animals that live directly above the sediment. Rocky-reef organisms form a large component of Antarctica's biodiversity and include algae as well as filter feeding animals such as sponges, lace corals, and fanworms. Many of these plants and animals live on boulders embedded within sediments. Information on the response of individuals, populations and communities to contamination will be used to develop sediment quality guidelines appropriate for the protection of the Antarctic environment. The toxicity of aqueous metals and metal-contaminated resuspended sediment to the spirorbid polychaete Spirorbis nordenskjoldi Ehlers, 1900 was assessed in assays conducted during the 2005/6 and 2006/7 field seasons. A more detailed description of the design of experiments and the methods used can be found in Hill et al, 2009. Spirorbids were exposed to aqueous solutions of copper, lead and zinc singularly, and in mixtures. Spirorbids were also exposed to resuspended metal-spiked sediments. Spirorbids attached to the brown alga Desmarestia sp were collected from Beall Island, Windmill Islands, East Antarctica, a clean site located approximately 2 km from Casey Station. Algae and animals were kept in the aquarium facility on station, in seawater maintained at 1 C and a 12-h light:dark photoperiod. Seawater was constantly aerated and changed every 5 to 6 d. Spirorbids were used within two weeks of their collection and fed once per week with plankton. Spirorbids were removed from the surface of algal blades 24 h before the start of a test, and allowed to recover in a constant-temperature chamber (CTC) at 0.5 C. Immediately before the start of tests, spirorbids were examined, and only healthy individuals were selected for tests. Spirorbids were determined to be healthy if their tentacular crown (fan) was extended and retracted quickly in response to stimuli. The download file contains further information on the data.

  • A survey of macrobenthic assemblages in soft-sediments was done at Casey Station, East Antarctica. Samples were taken by divers using hand-held corers (core size - 10 cm diameter by 10 cm deep). This was the final component of a large nested sampling survey extending over a three year periods with samples taken in three summers and one winter period. The aims were: 1) To examine spatial variation at several scales in these assemblages; 2) To determine if there were differences between potentially impacted areas and control areas; 3) To determine the level of replication, taxonomic resolution and data transformation that are appropriate to studies of human impacts in Antarctic soft-sediment assemblages. Cores were collected by divers in a hierarchical, spatially nested design incorporating 4 scales: Locations (1000s of metres apart), Sites (100s of metres), Plots (10s of metres) and among replicates within plots (~1 metre). This data set consists of 48 core samples from three locations, O'Brien Bay, Sparkes Bay and Wilkes. Samples are sorted mainly to species. Links to ASAC 1100. The fields in this dataset are: Location Site/Rep Species

  • A variety of epifaunal invertebrates were collected from hard substrates and soft sediment habitats at various sites in the Windmill Islands near Casey station in East Antarctica. Collected fauna were frozen (-18oC) and returned to Australia for analysis. Stable isotope analysis (carbon and nitrogen) was conducted on 376 samples. This work was completed as part of ASAC project 2948 (ASAC_2948), "TRENZ: The TRophic Ecology of the antarctic Nearshore Zone: local and global constraints on patterns and processes".

  • Metadata record for data from ASAC Project 2792 See the link below for public details on this project. Australia's Census of Antarctic Marine Life project. This project is a part of the international "Census of Antarctic Marine Life" (CAML) which is to be conducted during the International Polar Year. It is a collaborative contribution by Australia and France to understand the biodiversity of the oceans surrounding Antarctica, with particular emphasis on the fishes of the eastern part of the Australian Antarctic Territory. The biodiversity data, when added to that obtained by all other nations participating in the CAML, will serve as a robust reference for future examinations of the health of the Southern Ocean, and assist in the conservation and management of the region. 2007/2008 Season A. Plankton 1. The impact of climate change on the plankton. The pelagic ecosystem in the Southern Ocean has taken the brunt of human impact in the region and there is evidence that it is already responding to the effects of global climate change. Plankton is particularly sensitive to climate change and change in their biodiversity is expected to have serious ramifications through the rest of the ecosystem including the survival of higher predators. Some species are adapted to cold waters of Antarctic where some are supposedly cosmopolitan. Which will survive global warming? For how long will there be an Antarctic marine ecosystem? 2. Consequences of environmental change driven by past and current exploitation of living resources in the region, e.g. current scale fish and krill fisheries, fishery by-catch species, recovery of whales and seals. 3. "Ecosystem services" - The role of Southern Ocean plankton as source of human food (krill fishery or other) carbon draw down/mediation, bio-climate feedback though dimethyl sulphide production, bioproducts, sensitive indicators of ocean health, and foundation of the Antarctic marine ecosystem - no plankton, no ecosystem. B. Fish 1. What is the composition of the epipelagic, mesopelagic and benthic ichthyofaunas between the Antarctic Divergence and the coast at Dumont d'Urville? 2. How does the physical and biological structure of the water column, conditions of ice-cover and bottom topography influence the composition and distribution of these ichthyofaunas? 3. What changes in the community structure of the benthic ichthyofauna as a result from the passage of large icebergs? C. Benthos 1. What are the ecological and historical factors affecting benthic diversity? 2. How will benthic communities respond to change? We do not know how sensitive the Antarctic benthic communities are to global climate change, or to localised environmental change as seen in the Antarctic peninsula area, or to the impacts of increased trawling. We have no benchmark to compare the effects of change, although the effects of iceberg scouring and rate of recovery/re-colonisation will serve as a useful analogy for trawling perturbation. 3. What are the links between Antarctic and other faunas? This includes benthic-pelagic coupling, the benthos as a foraging zone for higher predators, and through the Antarctic Circumpolar Current - connections with other southern continents. Field sampling for this project was undertaken in the 2007/08 season, commencing in December and finishing in February 2008. Consequently, sample processing has only been underway for one or two months for plankton and pelagic fish samples. The demersal fish and benthic samples have only recently arrived at the National Natural History Museum (MNHN) in Paris ready for distribution to taxonomists and analysts. However, key CEAMARC collaborators who attended the recent post-field season CEAMARC workshop, Calvi April 2008, agreed that the use of three vessels for the field programme, instead of one ship as originally proposed, more than met expectations should sufficiently address all the objectives. Specifically, we have collected a substantial number of samples with sufficient sampling intensity and resolution to set the required benchmark of biodiversity in the survey for the pelagic, mesobathypelagic and benthic environments. This biodiversity benchmark will allow us to: - Compare changes in biodiversity with future CAML surveys and also with past surveys - Define legacy sites in the survey area for future CAML surveys and interim annual or biennial monitoring programmes to continuing the effects of climate change - Which species are most likely to be affected by climate change and those most likely to survive - Contribute to models looking at long term changes in species composition, ecosystem structure and function, survivorship of key species, effects of global warming, ocean acidification, and impacts on ecosystem service - Studies of the impact of trawling and iceberg scouring on the benthic and demersal communities - Compare pelagic, demersal and benthic communities in the survey area with those in the other CAML survey areas around Antarctica Sufficient samples of plankton, fish and benthos were also collected for genetic and molecular analyses to improve our taxonomic knowledge and address the CAML objective on understanding species radiation. Taken from the 2008-2009 Progress Report: Public summary of the season progress: This project is a part of the international "Census of Antarctic Marine Life" (CAML) conducted during International Polar Year. It is a collaborative contribution by Australia, France, Japan and Belgium to understand the biodiversity of Antarctic waters, with particular emphasis on plankton, fish and benthos of eastern Antarctica. In 2007/08, three ships surveyed this area with a range of traditional and modern sampling gear. The biodiversity data from this survey will be added to other CAML projects to serve as a robust reference for future examinations of the health of the Southern Ocean, and assist in its conservation and management.