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EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > FLATWORMS/FLUKES/TAPEWORMS

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  • We investigated the toxicity of copper, zinc and cadmium to the following taxa: copepods Tigriopus angulatus (Lang) and Harpacticus sp. (Order Harpacticoida, Family Harpacticidae); flatworm Obrimoposthia ohlini (Bergendal) (Order Seriata, Family Procerodidae); bivalve Gaimardia trapesina (Lamarck) (Order Veneroida, Family Gaimardiidae); sea cucumber Pseudopsolus macquariensis (Dendy) (Order Dendrochirotida, Family Cucumriidae); sea star Anasterias directa (Koeler) (Order Forcipulatida, Family Asteriidae). Sites chosen for the collection of invertebrates for this study were free of obvious signs of metal contamination, as verified by the analysis of seawater samples from collection sites by inductively coupled plasma optical emission spectrometry (ICP-OES). Six invertebrate species were selected for toxicity tests to represent a range of taxa and ecological niches. Individuals of the copepod Tigriopus angulatus were collected using fine mesh dip nets from rock pools high on the intertidal zone. Individuals of the flatworm Obrimoposthia ohlini were collected from the undersides of boulders, high in the intertidal zone. The copepod Harpacticus sp. and bivalve Gaimardia trapesina were collected from several macroalgae species at high energy locations in the intertidal zone. Individuals of the sea cucumber Pseudopsolus macquariensis were collected from rocks from high energy locations from the intertidal to subtidal zones. Juveniles of the sea star Anasterias directa were collected from rocks in deep pools, low in the intertidal zone. All experimental tests using O. ohlini, T. angulatus, P. macquariensis and A. directa were conducted at the AAD Kingston laboratories, while some tests with Harpacticus sp. and all tests with G. trapesina were conducted in the laboratory facilities on Macquarie Island. Adult life-stages were tested for all species except for P. macquairensis and A. directa in which juvenile stages were tested. Psedopsolus macquariensis released eggs in the aquarium which developed into juveniles prior to being used in tests, and juvenile A. directa were collected from the field. Each test involved exposure to copper, zinc or cadmium solution under a static non-renewal test regime over 14 days. Five metal concentrations plus a control were used for each test, with 3-5 replicates of each concentration. Where possible, tests were replicated. Concentrations used in replicate tests sometimes varied, as species sensitivity information accrued in tests was used to optimise subsequent tests. Metal test solutions in seawater were prepared 24 hours prior to the addition of animals, using 500 micrograms/L CuSO4, 500 micrograms/L ZnCl2 and 500 micrograms/L Cd SO4 MilliQ stock solutions. Seawater was filtered to 0.45 microns and water quality parameters were measured using a TPS 90-FL multimeter at the start and end of tests. Dissolved oxygen (DO) was greater than 80% saturation, salinity 35 ppt plus or minus 0.5, and pH was ~8.1-8.3 at the start of tests. All experimental vials and glassware were acid washed with 10% nitric acid and rinsed with MilliQ three times before use. Metal concentrations were determined using ICP-OES; samples of test solutions were taken at the start (day 0) and end of tests (day 14), filtered through a 0.45 microns syringe filter and acidified with 1% ultra-pure nitric acid. Measured concentrations at the start of tests were within 96% of nominal concentrations. In order to estimate exposure concentrations, the measured concentrations at days 0 and 14 were averaged. Tests were conducted in lidded plastic vials of varying sizes, depending on the size and number of individuals in the test. For both copepod species, there were 10 individuals per 50 mL in 70 mL vials; for P. macquariensis there were 8 individuals per 50 mL in 70 mL vials; and for O. ohlini, A. directa and G. trapesina, 10 individuals per 100 mL in 120 mL vials. Tests were conducted under a light-dark regime (at 2360 lux) of 18:6h light:dark in summer, 12:12 for tests for the rest of the year. Tests were kept in controlled temperature cabinets set at 6 degrees C, and temperatures within cabinets were monitored throughout the test using data loggers. Vials were checked daily and survival recorded on days 1, 2, 4, 7, 10 and 14. Individuals were considered dead, and removed from test vials, when for G. trapesina adductor muscles no longer closed shell; O. ohlini were inactive and covered in mucous; P. macquariensis and A. directa tube feet were no longer moving; T. angulatus and Harpacticus sp. urosomes were perpendicular to prosomes. Data are provided in a series of excel workbooks; one workbook per test species.

  • Study location and test species Subantarctic Macquarie Island lies in the Southern Ocean, just north of the Antarctic Convergence at 54 degrees 30' S, 158 degrees 57' E. Its climate is driven by oceanic processes, resulting in highly stable daily and inter-seasonal air and sea temperatures (Pendlebury and Barnes-Keoghan, 2007). Temperatures in intertidal rock pools (0.5 to 2 m deep) were logged with Thermochron ibuttons over two consecutive summers and averaged 6.5 (plus or minus 0.5) degrees C. The island is relatively pristine and in many areas there has been no past exposure to contamination. To confirm sites used for invertebrate collections were free from metal contamination, seawater samples were taken and analysed by inductively coupled plasma optical emission spectrometry (ICP-OES; Varian 720-ES; S1) The four invertebrate species used in this study were drawn from a range of taxa and ecological niches (Figure 1). The isopod Limnoria stephenseni was collected from floating fronds of the kelp Macrosystis pyrifera, which occurs several hundred meters offshore. The copepod Harpacticus sp. and bivalve Gaimardia trapesina were collected from algal species in the high energy shallow, subtidal zone. Finally, the flatworm Obrimoposthia ohlini was collected from the undersides of boulders throughout the intertidal zone. We hypothesised L. stephenseni would be particularly sensitive to changes in salinity and temperature due to its distribution in the deeper and relatively stable subtidal areas, while O. ohlini would be less sensitive due to its distribution high in the intertidal zone and exposure to naturally variable conditions. We reasoned that the remaining two species, G. trapesina, and Harpacticus sp. were intermediate in the conditions to which they are naturally exposed and hence would likely be intermediate in their response. Test procedure The combined effect of salinity, temperature and copper on biota was determined using a multi-factorial design. A range of copper concentrations were tested with each combination of temperatures and salinities, so that there were up to 9 copper toxicity tests simultaneously conducted per species (Table 1). Experiments on L. stephenseni and Harpacticus sp. were done on Macquarie Island within 2 to 3 days of collection, during which they were acclimated to laboratory conditions. While, G. trapesina and O. ohlini were transported by ship to Australia in a recirculating aquarium system and maintained in a recirculating aquarium at the Australian Antarctic Division in Hobart, both at 6 degreesC. These two taxa were used in experiments within 3 months of their collection. A limited number of G. trapesina and O. ohlini were available, resulting in fewer combinations of stressors tested. Controls for the temperature and salinity treatments were set at ambient levels of 35 plus or minus 0.1 ppt and 5.5 to 6 degreesC for all species. The lowered control temperature for the bivalve reflected the cooler seasonal temperatures at time of testing and lower position within the intertidal. Previous tests conducted under these ambient conditions provided information on the ranges of relevant copper concentrations, appropriate test durations, and water change regimes for each taxon (Holan et al., 2017, Holan et al., 2016b). From these previous studies, we determined that a test duration of 14 d was sometimes required with 7 d often being the best outcome for most species due to high control survival and sufficient response across concentrations. The bivalve G. trapesina was an exception to this due to unfavourable water quality after 3 days in previous work (Holan et al., 2016). For the other three species, this longer duration for acute tests, compared to tests with tropical and temperature species (24 to 96 h) was consistent with previous Antarctic studies that have required longer durations in order to elicit an acute response in biota (King and Riddle, 2001, Marcus Zamora et al., 2015, Sfiligoj et al., 2015). Experimental variables (volume of water, density of test organisms, copper concentrations, temperatures and salinities) differed for each experiment due to differences between each species (Table 1). The temperature increases that were tested (2 to 4 degreesC) reflected the increased sea and air temperatures predicted for the region tested by 2100 (Collins et al., 2013). Treatments were prepared 24 h prior to the addition of animals. Seawater was filtered to 0.45 microns and water quality was measured using a TPS 90-FL multimeter at the start and end of tests. Dissolved oxygen was greater than 80% saturation and pH was 8.1 to 8.3 at the start of tests. All experimental vials and glassware were washed with 10% nitric acid and rinsed with MilliQ water three times before use. Salinity of test solutions was prepared by dilution through the addition of MilliQ water. Copper treatments using the filtered seawater at altered salinities were prepared using 500mg/L CuSO4 (Analytical grade, Univar) in MilliQ water stock solution. Samples of test solutions for metal analysis by ICP-OES were taken at the start and end of tests (on days 0 and 14). Details of ICP-OES procedures are described in the Supplemental material (S4). Samples were taken using a 0.45 µm syringe filter that had been acid and Milli-Q rinsed. Samples were then acidified with 1% diluted ultra-pure nitric acid (65% Merck Suprapur). Measured concentrations at the start of tests were within 96% of nominal concentrations. In order to determine approximate exposure concentrations for each treatment, we averaged the 0 d and 14 d measured concentrations (Table 1). Tests were conducted in temperature controlled cabinets at a light intensity of 2360 lux. At the Macquarie Island station a light-dark regime of 16:8 h was used to mimic summer conditions. In the laboratories in Kingston, Australia, a 12:12 h regime was used to simulate Autum light conditions (as appropriate for the time of testing). Test individuals were slowly acclimated to treatment temperatures over 1 to 2 h before being added to treatments. Temperatures were monitored using Thermochron ibutton data loggers within the cabinets for the duration of the tests. Determination of mortality of individuals differed for each taxon. Mortality was recorded for Gaimardia trapesina when shells were open due to dysfunctional adductor muscles; for Obrimoposthia ohlini when individuals were inactive and covered in mucous; for Limnoria stephenseni when individuals were inactive after gentle stimulation with a stream of water from a pipette; and for Harpacticus sp. when urosomes were perpendicular to prosomes (as used in other studies with copepods; see Kwok and Leung, 2005). All dead individuals were removed from test vials.

  • Study location and species The four species used in this study were collected from subantarctic Macquarie Island (54.6167 degrees S, 158.8500 degrees E), just north of the Antarctic Convergence in the Southern Ocean. Sea temperatures surrounding Macquarie Island are relatively stable throughout the year, with average temperatures ranging from ~4 to 7 degrees C [25]. Collection sites were free from any obvious signs of contamination and did not have elevated concentrations of metals as confirmed by analysis of seawater samples from the collection sites by inductively coupled plasma optical emission spectrometry (ICP-OES; Varian 720-ES). Toxicity tests were conducted at Macquarie Island over the 2013/14 austral summer, and at the Australian Antarctic Division (AAD) in Tasmania, Australia, from 2013 to 2015. The aquarium at the AAD used for culturing and for holding biota prior to their use in tests was maintained at a temperature of 5.8 degrees C under flow-through conditions (at 0.49L/sec). Individuals for toxicity tests on the island and individuals for return to Australia for culturing were collected from a range of habitats within the intertidal and subtidal zones. All species were highly abundant in each of their respective habitats. The gastropod Laevilittorina caliginosa was collected from pools high on the intertidal zone; the flatworm Obrimoposthia ohlini, from the undersides of boulders from the intertidal to shallow subtidal areas; the bivalve Gaimardia trapesina, from several macroalgae species in high energy locations in the shallow subtidal; and the isopod Limnoria stephenseni, from the floating fronds of the kelp Macrocystis pyrifera, which were located several hundred meters offshore. Test specimens were acclimated to laboratory conditions 24 h to 48 h prior to commencement of tests. Juvenile flatworms, isopods and gastropods were all products of reproduction in the laboratory at the AAD, and hence their approximate age at testing is known. The flatworms hatched from small (2 mm in diameter) brown eggs, laid on rocks or on the side of aquaria. The flatworms exhibited age based morphological differences; juvenile flatworms were light grey in colour, while the adults were black. The gastropods hatched from small (1 mm in diameter) translucent eggs laid on weed, often in a cluster. For flatworms and gastropods, juveniles were not all the same age at testing due to differing hatching times, with ages ranging from 2 weeks to 3 months. In contrast, juvenile isopods were all the same age. Although brooding isopods were not observed, juveniles were noticed during routine feeding, thus were likely within 2-3 days of being released, 6 months after adults were brought from the field to the aquarium. The tests with these juvenile isopods were done within 1 week of their being observed. Care was taken to collect adults from the field, for each species, within a narrow size range to minimise differences in ages between individuals tested (Table 1). However, ages of adults individuals used in tests are unknown. The smaller size class of bivalves tested (juveniles: 2.5 plus or minus 0.5 mm, Table 1) was also collected from the field along with the adults (8.0 plus or minus 1.0 mm, Table 1). Based on knowledge on the growth rate of this species (0.8 mm per year; Everson [26], the smaller size class likely represents a young adult of approximately 2.5 to 4 y old, as opposed to a juvenile stage, and adults collected were approximately 9 to 11 y old. Toxicity tests A static non-renewal test regime was used for all tests. Two replicate tests were done for each species at each life stage, with the exception of the juvenile isopods, where due to the limited number of individuals available, only one test was done. Longer tests durations of 14 days were done for acute responses due to the longer life span and response to contaminants compared to temperate and tropical species as determined in previous studies [7, 27]. All experimental vials and glassware were washed in 10% nitric acid and rinsed thoroughly with MilliQ water three times before use. Tests were done in lidded polyethylene vials of varying sizes, depending on the size and number of individuals in the test (Table 1). Water was not aerated as DO stayed relatively high for tests due to high dissolution rates in cold water. Acid washed and Milli-Q rinsed mesh (600 micron nylon) was provided for isopods to rest on, while no structure was added to vials for the other test species. Test solutions were prepared 24 h prior to the addition of invertebrates. Five copper concentrations in seawater were prepared using a 500 mg/L Univar analytical grade CuSO4 in MilliQ stock solution, plus a control for each test. Seawater was filtered to 0.45 microns, and water quality parameters were measured using a TPS 90-FL multimeter at the start (d 0) and end (d 14) of tests. Dissolved oxygen (DO) was greater than 80% saturation, salinity was 33 to 35 ppt, and pH was 8.1 to 8.3 at the start of tests. Tests were kept in controlled temperature cabinets set at 6 degrees C under 16:8h light:dark during the summer, and 12:12 for tests during the rest of the year (light intensity of 2360 lux). Temperatures within cabinets were monitored throughout the test using Thermochron iButton data loggers. Water samples of each test concentration were taken at the start (day 0) and end of tests (day 14). Samples were filtered through an acid and Milli-Q rinsed, 0.45 microns Minisart syringe filter and acidified with 1% ultra-pure nitric acid before being analysed by ICP-OES to determine dissolved metal concentrations. Measured concentrations at the start of tests were within 96% of nominal target concentrations. Averages between measured concentrations at the start and end of tests were made to estimate exposure concentrations, which were subsequently used in statistical analyses to determine point estimates (Table 2). Both survival and sublethal (behavioural) endpoints were used to determine sensitivity to copper. Vials were checked daily and survival and sublethal responses were observed and recorded on days 1, 2, 4, 7, 10 and 14. Tests were terminated when surviving individuals occurred in less than two concentrations, which was generally at 14 d for all species except for bivalves, in which this occurred sooner (7 to 10 d). Gastropods were scored as dead when their operculum was open and there was no response to stimulus (touch of a probe) on the operculum. Flatworms were scored as dead when there was no movement. Bivalves was scored as dead when there was no movement and when the shells were gaping open due to dysfunctional adductor muscles. Isopods were scored as dead when there was no movement of any appendages. The behavioural endpoint scored for each species was attachment, which indicated healthy and active individuals. For gastropods, this meant the foot was fully extended and attached to experimental vials; for flatworms, the whole body was able to attach (as those affected by copper appeared slightly contracted and could not lie flat); for bivalves, the byssal threads were used to fix individuals to the bottom of the vial, with the siphon also visible and shell slightly open for water exchange; and for isopods, individuals were either holding onto the provided mesh or were swimming, in which case they often reattached to the mesh during observation.

  • 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 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.

  • The biodiversity database is planned to be a reference on Antarctic and subantarctic flora and fauna collated by the Regional Sensitivity to Climate Change (RiSCC) group and developed by the Australian Antarctic Data Centre. Searches are available in the following areas: Taxonomy Protection and convention measures (protected species) Observations Scientific Bibliographies

  • 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.

  • Untreated, macerated wastewater effluent has been discharged to the sea at Davis Station since 2005, when the old wastewater treatment infrastructure was removed. This environmental assessment was instigated to guide the choice of the most suitable wastewater treatment facility at Davis. The assessment will support decisions that enable Australia to meet the standards set for the discharge of wastewaters in Antarctica in national legislation (Waste Management Regulations of the Antarctic Treaty Environmental Protection Act - ATEP) and to meet international commitments (the Madrid Protocol) and to meet Australia's aspirations to be a leader in Antarctic environmental protection. The overall objective was to provide environmental information in support of an operational infrastructure project to upgrade wastewater treatment at Davis. This information is required to ensure that the upgrade satisfies national legislation (ATEP/Waste Management Regulations), international commitments (the Madrid Protocol) and maintain the AAD's status as an international leader in environmental management. The specific objectives were to: 1. Wastewater properties: Determine the properties of discharged wastewater (contaminant levels, toxicity, microbiological hazards) as the basis for recommendations on the required level of treatment and provide further consideration of what might constitute adequate dilution and dispersal for discharge to the nearshore marine environment 2. Dispersal and dilution characteristics of marine environment: Assess the dispersing characteristics of the immediate nearshore marine environment in the vicinity of Davis Station to determine whether conditions at the existing site of effluent discharge are adequate to meet the ATEP requirement of initial dilution and rapid dispersal. 3. Environmental impacts: Describe the nature and extent of impacts to the marine environment associated with present wastewater discharge practices at Davis and determine whether wastewater discharge practices have adversely affected the local environment. 4. Evaluate treatment options: Evaluate the different levels of treatment required to mitigate and/or prevent various environmental impacts and reduce environmental risks.

  • 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.

  • 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.