Publications

Abstract Australia’s tidal marshes have suffered significant losses but their recently recognised importance in CO 2 sequestration is creating opportunities for their protection and restoration. We compiled all available data on soil organic carbon (OC) storage in Australia’s tidal marshes (323 cores). OC stocks in the surface 1 m averaged 165.41 (SE 6.96) Mg OC ha −1 (range 14–963 Mg OC ha −1 ). The mean OC accumulation rate was 0.55 ± 0.02 Mg OC ha −1 yr −1 . Geomorphology was the most important predictor of OC stocks, with fluvial sites having twice the stock of OC as seaward sites. Australia’s 1.4 million hectares of tidal marshes contain an estimated 212 million tonnes of OC in the surface 1 m, with a potential CO 2 -equivalent value of $USD7.19 billion. Annual sequestration is 0.75 Tg OC yr −1 , with a CO 2 -equivalent value of $USD28.02 million per annum. This study provides the most comprehensive estimates of tidal marsh blue carbon in Australia, and illustrates their importance in climate change mitigation and adaptation, acting as CO 2 sinks and buffering the impacts of rising sea level. We outline potential further development of carbon offset schemes to restore the sequestration capacity and other ecosystem services provided by Australia tidal marshes.

Abstract Graphene has shown considerable potential for sensing magnetic fields based on the Hall Effect, due to its high carrier mobility, low sheet carrier density, and low-temperature dependence. However, the cost of graphene in comparison to conventional materials has meant that its uptake in electronic manufacturing has been slow. To lower technological barriers and bring more widespread adoption of graphene Hall sensors, we are using a one-step laser scribing process that does not rely on multiple steps, toxic chemicals, and subsequent treatments. Laser-scribed graphene Hall sensors offer a linear response to magnetic fields with a normalized sensitivity of ~1.12 V/AT. They also exhibit a low constant noise voltage floor of ~ 50 nV/ $$\sqrt {{\mathrm{Hz}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mrow> <mml:mi>Hz</mml:mi> </mml:mrow> </mml:msqrt> </mml:math> for a bias current of 100 µA at room temperature, which is comparable with state-of-the-art low-noise Hall sensors. The sensors combine a high bendability, come with high robustness and operating temperatures up to 400 °C. They enable device ideas in various areas, for instance, soft robotics. As an example, we combined a laser-scribed graphene sensor with a deformable elastomer and flexible magnet to realize low-cost, compliant, and customizable tactile sensors.

Iridocytes, containing multiple stacks of proteinaceous platelets and crystalized guanine, alternating with thin cytoplasm sheets, are specialized cells that act as multilayer nano-reflectors. Convergence evolution led to their arising across a broad range of organisms, including giant clams of the Tridacninae subfamily - the only sessile and photosymbiotic organism, among animals known to possess iridocytes. Through the interference of light with their nanoscale architecture, iridocytes generate 'structural colors', which are reported to serve different purposes, from intra-species communication to camouflage. In giant clams, iridocytes were previously reported to promote a lateral - and forward scattering of photosynthetically productive radiation (PAR) into the clam tissue, as well as the back reflection of non-productive wavelengths. Hence, they are assumed to promote an increased efficiency in the use of available solar energy, while simultaneously preventing photodamage of the algal symbionts. We report the use of guanine crystals within Tridacna maxima giant clam iridocytes as a basis for photonic cooperation between the bivalve host and their photosynthetic symbionts. Our results suggest that, in addition to the previously described scattering processes, iridocytes absorb potentially damaging UV radiation (UVR) and, through successive emission, emit light at longer wavelengths, which is then absorbed by the photosynthetic pigments of the algal symbionts. Consequently, both, host and algal symbionts are sheltered from (potentially) damaging UVR, while the available solar energy within the PAR spectrum increases, thereby potentially enhancing photosynthetic and calcification rates in this large bivalve. Further, our results suggest that this photonic cooperation could be responsible for the broad repertoire of colors that characterizes the highly diverse mantle patterns found in T. maxima.

Climate change challenges organisms to adapt or move to track changes in environments in space and time. We used two measures of thermal shifts from analyses of global temperatures over the past 50 years to describe the pace of climate change that species should track: the velocity of climate change (geographic shifts of isotherms over time) and the shift in seasonal timing of temperatures. Both measures are higher in the ocean than on land at some latitudes, despite slower ocean warming. These indices give a complex mosaic of predicted range shifts and phenology changes that deviate from simple poleward migration and earlier springs or later falls. They also emphasize potential conservation concerns, because areas of high marine biodiversity often have greater velocities of climate change and seasonal shifts.

People experiencing homelessness and/or complex needs often require targeted health services to address unique vulnerabilities. COVID-19 restrictions acted as a barrier for this group accessing health and alcohol and other drug (AOD) treatment services. The Haymarket Foundation, an accommodation and health facility in Australia, transitioned from in-person AOD-counselling services to online consultations. Clients accessing these services were tracked, from March 2019 to November 2020, to assess the impact of the switch to telehealth on client retention.Qualitative analysis of Haymarket clients' service experience surveys and quantitative descriptives of "no-show" (nonattended sessions) rates and survival analysis of client treatment separations were completed to assess the impact of transitioning to telehealth on client retention.Although the initial transition to telehealth in March 2020 minimally impacted client no-show rates, reinstated government restrictions in June/July 2020 coincided with increasing no-shows and a substantial increase in treatment exits without notice, especially amongst males. Qualitative analysis showed clients had mixed feelings towards telehealth: some attributed their dissatisfaction to the inability to build rapport with their counsellor online, or with COVID-19 in general. Others appreciated the availability and genuine care of their counsellors through either setting.Telehealth may be a feasible replacement for face-to-face AOD counselling for people experiencing homelessness, however further investigation needs to be conducted to understand factors associated with improved client retention. SO WHAT?: This pilot demonstrates telehealth may be a feasible ongoing feature of health promotion for vulnerable high-needs populations, including people experiencing homelessness who use substances.

Abstract Background The ocean microbiota modulates global biogeochemical cycles and changes in its configuration may have large-scale consequences. Yet, the underlying ecological mechanisms structuring it are unclear. Here, we investigate how fundamental ecological mechanisms ( selection , dispersal and ecological drift ) shape the smallest members of the tropical and subtropical surface-ocean microbiota: prokaryotes and minute eukaryotes (picoeukaryotes). Furthermore, we investigate the agents exerting abiotic selection on this assemblage as well as the spatial patterns emerging from the action of ecological mechanisms. To explore this, we analysed the composition of surface-ocean prokaryotic and picoeukaryotic communities using DNA-sequence data (16S- and 18S-rRNA genes) collected during the circumglobal expeditions Malaspina - 2010 and TARA - Oceans . Results We found that the two main components of the tropical and subtropical surface-ocean microbiota, prokaryotes and picoeukaryotes, appear to be structured by different ecological mechanisms. Picoeukaryotic communities were predominantly structured by dispersal-limitation, while prokaryotic counterparts appeared to be shaped by the combined action of dispersal-limitation, selection and drift. Temperature-driven selection appeared as a major factor, out of a few selected factors, influencing species co-occurrence networks in prokaryotes but not in picoeukaryotes, indicating that association patterns may contribute to understand ocean microbiota structure and response to selection. Other measured abiotic variables seemed to have limited selective effects on community structure in the tropical and subtropical ocean. Picoeukaryotes displayed a higher spatial differentiation between communities and a higher distance decay when compared to prokaryotes, consistent with a scenario of higher dispersal limitation in the former after considering environmental heterogeneity. Lastly, random dynamics or drift seemed to have a more important role in structuring prokaryotic communities than picoeukaryotic counterparts. Conclusions The differential action of ecological mechanisms seems to cause contrasting biogeography, in the tropical and subtropical ocean, among the smallest surface plankton, prokaryotes and picoeukaryotes. This suggests that the idiosyncrasy of the main constituents of the ocean microbiota should be considered in order to understand its current and future configuration, which is especially relevant in a context of global change, where the reaction of surface ocean plankton to temperature increase is still unclear.