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EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > SPONGES

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  • The natural world is a mosaic of different habitats and biological communities; the tiles of this mosaic may be small but the patterns formed can be measured at many scales from metres to thousands of kilometres. Understanding these patterns is important to protecting biodiversity. We will identify major scales of variability in Antarctic coastal habitats, biological communities and processes that create them. We will also document scales of impacts caused by humans in Antarctica and potential impacts of future climate change driven by key processes (changes in sea-ice). This information will contribute to environmental management to protect Antarctic coastal ecosystems. This record is the parent record for all metadata records relating to ASAC project 2201. See the child metadata records for access to the data arising from this project. See the project link for a full listing of personnel involved in this project.

  • 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.

  • 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.

  • 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

  • Underwater footage was taken with a Sony digital Handycam mounted in a pressure case on a roll cage, and then trawled off the back of the Aurora Australis. The footage was taken primarily of benthic habitats, and was done on an opportunistic basis, rather than part of a systematic trawling survey. Most of the footage was taken within the Heard Island Exclusive Economic Zone (EEZ), but some footage was also taken between Mawson and Davis off the Antarctic continent. Footage of both areas (highlights of Heard Island, and of Prydz Bay) are available at the provided URL. The footage was collected by: Tony Veness Bryan Scott Andrew Tabor Kelvin Cope Andrew Cawthorn Stuart Crapper

  • A total of 701 still images were analysed from 10 transects on the Sabrina Coast continental shelf. Imagery was collected from the RVIB Nathaniel B Palmer (NBP 14-02, 29 January - 16 March 2014) across a greater than 3000 km2 area. A 'yoyo' camera, with downward facing digital still and video cameras mounted within a tubular steel frame, was deployed on a coaxial cable to image the seafloor. The Ocean Imaging Systems DSC 10000 digital still camera (10.2 megapixel, 20 mm, Nikon D-80 camera) was contained within titanium housing. Camera settings were: F-8, focus 1.9 m, ASA-400. An Ocean Imaging Systems 3831 Strobe (200 W-S) was positioned 1m from the camera at an angle of 26 degrees from vertical. A Model 494 bottom contact switch triggered the camera and strobe at 2.5m above the sea floor, imaging ~ 4.8m2 of sea floor. Parallel laser beams (10 cm separation) provided a reference scale for the images. Transects were conducted at a ship's speed of ~1 knot. Still images were characterised for main taxonomic groups and sediment properties based on the CATAMI scheme of Althaus et al. 2015.

  • 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.

  • Project Objectives 1) To describe trophic relationships in near shore marine benthic ecosystems of East Antarctica and determine the importance of environmental forces (such as sea ice and primary production) to the structure of food webs and biological interactions in benthic assemblages. 2) To determine how marine benthic food webs in East Antarctica respond to local scale disturbances (such as sewage outfalls and abandoned waste disposal sites) and develop predictive models of the influence of local human activities on trophic relationships. 3) To develop predictive models for the potential effects of global climate change on the trophic structure and function of near shore marine benthic assemblages and determine the sensitivity of Antarctic near shore ecosystems as sentinels of climate change. 4) To measure toxicity of organic contaminants to Antarctic marine benthic invertebrates, determine concentrations in upper trophic level fauna and to model the risk of bioaccumulation of organic contaminants (from local and global sources) in near shore marine benthic food webs in East Antarctica. Collections of organisms from coastal ecosystems around Casey and Davis stations were made between 2006/07 and 2010/11. These samples have been used in a variety of ways to examine trophic interactions in Antarctic coastal ecosystems. Methods include stable isotope analysis, diet and gut contents DNA analysis, analysis of POPs (persistent organic pollutants) and the impacts of local disturbances on food webs.

  • Project Objectives 1) To describe trophic relationships in near shore marine benthic ecosystems of East Antarctica and determine the importance of environmental forces (such as sea ice and primary production) to the structure of food webs and biological interactions in benthic assemblages. 2) To determine how marine benthic food webs in East Antarctica respond to local scale disturbances (such as sewage outfalls and abandoned waste disposal sites) and develop predictive models of the influence of local human activities on trophic relationships. Collections of organisms from coastal ecosystems around Casey and Davis stations were made between 2006/07 and 2010/11.