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Climate Change

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  • Metadata record for data from ASAC Project 2753 See the link below for public details on this project. Public Weddell and southern elephant seals are high-order predators living in the Antarctic marine ecosystem. Their place in that ecosystem is the result of a long history of evolutionary adaptation to a challenging and changing environment. The objective of this study is to understand how Weddell and elephant seals have adapted and are responding to today's rapidly changing Antarctic environment. This study will use current and innovative approaches in demographic (population) analyses and diet techniques to analyse changes in the seals' demographic parameters and historical aspects of their ecology. Project objectives: Objective 1. Seek a greater understanding of the links between climate based environmental parameters and Weddell seal demographic performance. Objective 2. Test the hypothesis that the foraging ecology and presence of male southern elephant seals hauling out along the Antarctic coast are regulated by variation in the extent and concentration of coastal sea-ice. Objective 3. Examine contemporary and historical dietary shifts in an Antarctic marine predator by using a non-invasive technique, stable isotope analyses. Objective 4. Construct models of potential population performance for Weddell and southern elephant seals with predicted climate change Taken from the 2008-2009 Progress Report: Progress against objectives: The first season of field work was conducted at Casey in December 2008. This comprised of surveys of the region to locate breeding and moulting haulouts, weighing and flipper tagging of Weddell seal pups and flipper tagging of sub adult elephant seals. Specifically: Tagging Leptonychotes weddellii. A total of 30 pups were flipper tagged. Tagging: 46 sub-adult male Mirounga leonina in Browning Peninsula region. Aerial survey of the Casey fast-ice conducted on 30/1/2009. Conducted at 1000, 500, 300 ft. A total of 33 seals counted. Taken from the 2009-2010 Progress Report: Progress against objectives: 1. Observations of tagged Weddell seals made in the Vestfold Hills during the breeding season. 2. Counts were made of elephant seals at Davis station 3. No progress made due to postponement of project at Casey 4. Data collected on Weddell and elephant seals at Davis. No modelling undertaken in this year

  • Metadata record for data from AAS (ASAC) project 3134. This metadata record deals specifically with the objectives relating to "Effects of Ocean Warming and Ocean Acidification on the Echinoderm Sterechinus neumayeri". These data are published in the following paper: Ericson, JA and Ho, MA and Miskelly, A and King, CK and Virtue, P and Tilbrook, BD and Byrne, M, Combined effects of two ocean change stressors, warming and acidification, on fertilization and early development of the Antarctic echinoid Sterechinus neumayeri, Polar Biology, online, (online) pp. 1-8. ISSN 0722-4060 (2011) The study examined the effects of decreased seawater pH and increased seawater temperature on Sterechinus neumayeri fertilisation and embryology. Experiments were carried out in the laboratories at Davis Station, Antarctica during the 2010/2011 summer season as part of a wider research programme looking at the effects of climate change and human impacts on Antarctic marine invertebrates. The research was conducted under project 3134 'Vulnerability of Antarctic marine benthos to increased temperatures and ocean acidification associated with climate change'. Public Ocean acidification and warming are global phenomena that will impact marine biota through the 21st century. This project will provide urgently needed predictive information on the likely survivorship of benthic invertebrates in near shore Antarctic environments that is crucial for risk assessment of potential future changes to oceans. As oceans acidify carbonate saturation decreases, reducing the material required to produce marine skeletons. By examining the effects of increased ocean temperature and acidification on planktonic and benthic life stages of both calcifying and non-calcifying ecologically important organisms, predictions can be made on the potential vulnerability of marine biota to climatic change.

  • Metadata record for data from AAS (ASAC) project 3134. Data from this project will be available via the child records. Public Ocean acidification and warming are global phenomena that will impact marine biota through the 21st century. This project will provide urgently needed predictive information on the likely survivorship of benthic invertebrates in near shore Antarctic environments that is crucial for risk assessment of potential future changes to oceans. As oceans acidify carbonate saturation decreases, reducing the material required to produce marine skeletons. By examining the effects of increased ocean temperature and acidification on planktonic and benthic life stages of both calcifying and non-calcifying ecologically important organisms, predictions can be made on the potential vulnerability of marine biota to climatic change. Project Objectives: This project aims to deliver one of the first assessments of the impacts that ocean warming and acidification through rising CO2 levels will have on Antarctic benthic marine invertebrates and of the adaptive capacity of common Antarctic biota to climate change. The developmental success of species that have a skeleton will be compared to those that do not under controlled conditions of increased sea water temperature and CO2. A comparison of the responses and sensitivity of developmental stages of calcifiers (echinoids, bivalves) and non-calcifiers (asteroids) to elevated CO2 and temperature will generate much needed empirical data for assessment of risk and adaptive capacity of Antarctica's marine biota and will enable predictions of how benthic invertebrates will fare with respect to climate change scenarios. The specific aims of the project are to: 1 - examine the impacts of predicted future elevated ocean temperatures and CO2 on fertilisation success, embryonic and larval development of Antarctic molluscs and echinoderms 2 - document skeletal calcification and morphology and growth in larvae under controlled conditions of increased sea water temperature and CO2. 3 - compare the dynamics of biomineralisation with respect to the elemental composition in response to increased temperature and CO2 in species with aragonite and calcite exoskeletons (bivalves) and porous high magnesium calcite endoskeletons (echinoids) to assess the potential for an in-built adaptive response in calcification 4 - used as a biomarker measure of stress and impaired calcification. 5 - compare biomineralisation and elemental signatures in skeletons in larvae of Antarctic molluscs and echinoderms under climate change scenarios with that determined for related species at lower latitudes to assess the relative sensitivity and vulnerability of Antarctic biota. Taken from the 2009-2010 Progress Report: Progress against objectives: 1. Unsuccessful as target species, Sterechinus neumayeri had already passed its spawning period, and attempts to spawn and fertilise the Antarctic bivalve, Laternula ellipticaskeleta failed. 2. Skeletal calcification and morphology of juveniles of Abatus nimrodi were successfully documented under controlled conditions of ocean warming and acidification. 3. Juveniles of A. nimrodi were preserved and returned to Australia in order to compare the dynamics of biomineralisation and skeletal mineralogy. 4. No heat shock protein experiments were carried out. 5. Air-dried tests of S. neumayeri and A. nimrodi were RTA'd in order to compare the dynamics of biomineralisation and skeletal mineralogy. Taken from some project abstracts written by two students working on the project: Impacts of ocean acidification and increasing seawater temperature on the early life history of the Antarctic echinoderm Sterechinus neumayeri. Simultaneous effects of ocean acidification and temperature change in Antarctic environments warrant investigation as little is known about the synergistic consequences of these parameters on Antarctic benthic species. Fertilisation success, embryo cleavage, blastulation and gastrulation were documented in the sea urchin Sterechinus neumayeri, reared for up to 12 days under experimental pCO2 and elevated temperature scenarios predicted by the IPCC (2007) over the next century. Experimental treatments included controls (-1 degrees C, pH 8.0), elevated temperature (1 degrees C, 3 degrees C) and decreased pH (7.8, 7.6) in all combinations in a multi-factorial design. Preliminary results suggest that fertilisation and development up to the gastrula stages are robust to increases in pCO2 and temperature predicted by the year 2100. Percentages of normally developing blastula and gastrula were also slightly higher in temperatures 2 degrees C above ambient. Impacts of ocean acidification and increasing seawater temperature on juveniles of two Antarctic heart urchins, Abatus ingens and Abatus shackletoni. Simultaneous effects of ocean acidification and temperature change in Antarctic environments warrant investigation as little is known about the synergistic consequences of these factors on Antarctic benthic species. Juvenile Abatus ingens and Abatus shackletoni were incubated under experimental pCO2 and elevated temperature scenarios reflective of those predicted by the IPCC (2007). Direct development from embryos to juveniles occurs in these species without a pelagic larval phase and the developing young are lecithotrophic for an extended period. Adult urchins were collected near Davis Station during the Austral summer season (January-February 2011). Juveniles were extracted from the parental brood pouch and reared in flow-through experimental treatments for 4 weeks. CO2-enriched air was supplied to seawater in which pCO2 was regulated at the target levels of 448 plus or minus 6.51 (pH 8.01 plus or minus 0.005), 846 plus or minus 6.58 (pH 7.83 plus or minus 0.005) and 1371 plus or minus 7.34 (pH 7.63 plus or minus 0.007) ppm and seawater temperature was set at -1 plus or minus 0.03 degrees C (Control) and 1 plus or minus 0.32 degrees C. Preliminary results from this investigation showed significant increases in spine growth in juveniles of both A.ingens and A. shackletoni over the experimental period. However, juveniles reared in 1 degrees C significantly exhibited more incidences of epithelial separation in the spines compared to those reared in -1 degrees C. This suggests that, although there is an inherent capacity for tolerance of varying levels of pH in seawater in the absence of the protection afforded by the maternal brood pouch, these juveniles are still at risk from increasing temperatures.