http://hdl.handle.net/10453/82 Thu, 23 May 2013 19:06:53 GMT 2013-05-23T19:06:53Z http://hdl.handle.net/10453/18072 Early development and molecular plasticity in the Mediterranean sea urchin Paracentrotus lividus exposed to CO2-driven acidification Martin Sophie; Richier Sophie; Pedrotti Maria-Luiza; Dupont Sam; Castejon Charlotte; Gerakis Yannis; Kerros Marie-Emmanuelle; Oberhaensli Francois; Teyssie Jean-Louis; Jeffree Ross; Gattuso Jean-Pierre Ocean acidification is predicted to have significant effects on benthic calcifying invertebrates, in particular on their early developmental stages. Echinoderm larvae could be particularly vulnerable to decreased pH, with major consequences for adult populations. The objective of this study was to understand how ocean acidification would affect the initial life stages of the sea urchin Paracentrotus lividus, a common species that is widely distributed in the Mediterranean Sea and the NE Atlantic. The effects of decreased pH (elevated PCO2) were investigated through physiological and molecular analyses on both embryonic and larval stages. Eggs and larvae were reared in Mediterranean seawater at six pH levels, i.e. pHTï¿ 8.1, 7.9, 7.7, 7.5, 7.25 and 7.0. Fertilization success, survival, growth and calcification rates were monitored over a 3ï¿ day period. The expression of genes coding for key proteins involved in development and biomineralization was also monitored. Paracentrotus lividus appears to be extremely resistant to low pH, with no effect on fertilization success or larval survival. Larval growth was slowed when exposed to low pH but with no direct impact on relative larval morphology or calcification down to pHT 7.25. Consequently, at a given time, larvae exposed to low pH were present at a normal but delayed larval stage. More surprisingly, candidate genes involved in development and biomineralization were upregulated by factors of up to 26 at low pH. Our results revealed plasticity at the gene expression level that allows a normal, but delayed, development under low pH conditions. Sat, 01 Jan 2011 00:00:00 GMT http://hdl.handle.net/10453/18072 2011-01-01T00:00:00Z http://hdl.handle.net/10453/18073 Actual Evapotranspiration Estimation By Ground And Remote Sensing Methods: The Australian Experience Glenn E.P.; Doody T.M.; Guerschman J.P.; Huete Alfredo; King E.A.; Mcvicar T.R.; Van A.I.J.M.; Van T.G.; Yebra M.; Zhang Y. On average, Australia is a dry continent with many competing uses for water. Hence, there is an urgent need to know actual evapotranspiration (ETa) patterns across wide areas of agricultural and natural ecosystems, as opposed to just point measurements of ETa. The Australian Government has tasked the science agencies with operationally developing monthly and annual estimates of ETa and other hydrological variables, and with forecasting water availability over periods of days to decades, as part of its national water assessment programme. To meet these needs, Australian researchers have become leaders in developing large-area methods for estimating ETa at regional and continental scales. Ground methods include meteorological models, eddy covariance towers, sap flow sensors and catchment water balance models. Remote sensing methods use thermal infrared, mid infrared and/or vegetation indices usually combined with meteorological data to estimate ETa. Ground and remote sensing ETa estimates are assimilated into the Australian Water Resource Assessment, which issues annual estimates of the state of the continental water balance for policy and planning purposes. The best ETa models are estimated to have an error or uncertainty of 10% to 20% in Australia. Developments in Australian ETa research over the past 20?years are reviewed, and sources of error and uncertainty in current methods and models are discussed. Sat, 01 Jan 2011 00:00:00 GMT http://hdl.handle.net/10453/18073 2011-01-01T00:00:00Z http://hdl.handle.net/10453/18075 Surveying rip current survivors: preliminary insights into the experiences of being caught in rip currents Drozdzewski Danielle; Shaw Wendy; Dominey-Howes Dale; Brander Rob; Walton Todd; Gero Anna; Sherker Shauna; Goff James; Edwick Blake This paper begins a process of addressing a significant gap in knowledge about people's responses to being caught in rip currents. While rip currents are the primary hazard facing recreational ocean swimmers in Australia, debate exists about the best advice to give swimmers caught in rip currents. Such surf rescue advice - on what to do and how to respond when caught in a rip - relies on empirical evidence. However, at present, knowledge about swimmers reactions and responses to rip currents is limited. This gap is a considerable barrier to providing effective advice to beach goers and to understanding how this advice is utilised (or not) when actually caught in the rip current. This paper reports the findings of a pilot study that focussed on garnering a better understanding of swimmers' experiences when caught in rip currents. A large scale questionnaire survey instrument generated data about rip current survivors' demographics, knowledge of beach safety and their reactions and responses when caught in a rip current. A mix of online and paper surveys produced a total of 671 completed surveys. Respondents were predominantly an informed group in terms of rip current knowledge, beach experience and had a high self-rated swimming ability. Preliminary insights from the survey show that most respondents recalled a 'swim across the rip/parallel to the beach' message when caught in the rip and most escaped unassisted by acting on this message. However, while nearly a quarter of respondents recalled a message of 'not to panic', short answer responses revealed that the onset of panic inhibited some respondents from recalling or enacting any other type of beach safety message when caught in the rip current. Results also showed that despite the research sample being younger, competent and frequent ocean swimmers, they were more likely to swim at unpatrolled beaches and outside of the red and yellow safety flags. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10453/18075 2012-01-01T00:00:00Z http://hdl.handle.net/10453/18074 Fungal diversity of shallow aquifers in Southeastern Australia Lategan Maria; Torpy Fraser; Newby S.; Stephenson S.; Hose G. The diversity of groundwater mycobiota remains relatively unknown and unchartered. As a first description of the fungal diversity in Australian aquifers we explored the distribution, abundance and diversity of fungal assemblages in samples from an alluvial (Bylong) and two sandy (Tomago; Botany Sands) unconfined aquifers in coastal catchments of NSW, Australia. A total of 89 strains were isolated with 54 Eumycotan taxa identified. The Botany Sands aquifer, with a history of industrial chlorinated hydrocarbon contamination along a hydraulic gradient, yielded the highest richness with 23 identifiable taxa, followed by Tomago with 17 and Bylong with 14. Despite differences in geology and land use, the aquifers shared similarities in their fungal assemblages with Penicillium, Rhodotorula, Paecilomyces and Cladosporium spp. common to all sites. Fungal assemblages were notably similar between the Bylong and Tomago samples and differed from the Botany samples in composition and heterogeneity. Taxa appeared to cluster into two main groups according to their association with environmental conditions; with the taxa common to the Botany aquifer correlating strongly with higher dissolved oxygen concentrations. The diversity and spatial heterogeneity of groundwater mycobiota appeared to be influenced by both anthropogenic contaminants and associated environmental variables. Based on the criteria of ubiquity, abundance and potential sensitivity to contamination, Penicillium and Rhodotorula spp. might be fitting taxa for monitoring groundwater quality. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10453/18074 2012-01-01T00:00:00Z