Learning for Sustainability: Partnership for the Goals

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Science Undergraduates Are Motivated to Undertake Leadership Education to Enhance Employability and Impact

Leadership education is increasingly prevalent, with tertiary institutions offering leadership programs in a variety of formats. Leadership curricula are traditionally underrepresented in science, but provide a promising way to develop a range of transferable skills. Moving forward, it is important for educators and curriculum designers to ask why science students should choose to layer their discipline-specific education with leadership education. Our study aimed to identify the key motivations for undergraduates to choose leadership education alongside a traditional science degree. We surveyed 70 undergraduates across the Bachelor of Science, Bachelor of Science - Advanced Research (Honours) and two emerging science leadership programs (Science Future Leaders and Bachelor of Science Advanced - Global Challenges (Honours)) at Monash University, Australia. We also interviewed 13 students, asking open-ended questions about their motivations for undertaking leadership courses and coded responses to identify common themes. All interviewed students indicated that employability was important in their decision-making. Most respondents were motivated to develop transferable skills and broaden their employment options, competitiveness and adaptability in what scholars have described as an uncertain and dynamic workforce. Some respondents also cited a wish to increase their capacity to have a positive impact in society during their careers. Our findings suggest that today’s Australian science students are receptive to broadening their skills, attributes and competencies beyond traditional technical and content-rich discipline training

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Comparative food web impacts of a native and an invasive fish in dynamic floodplain wetlands

Invasive species cause major declines in biodiversity globally through a range of mechanisms including predation, displacement of endemic taxa, and complex food web impacts. While the dramatic effects of invaders have been well documented, less is known about cases where global invaders and native species coexist, the factors that facilitate this, and the comparative food web effects of invasive and native competitors. The invasive poeciliid fish Gambusia holbrooki (Eastern Mosquitofish) has been shown to have dramatic impacts on freshwater systems on four continents. These include trophic cascades resulting in algal blooms, changes in invertebrate community composition, and displacement of endemic fish and frogs. However in some situations they coexist with other fish species, with apparently only minor effects on native biodiversity and ecosystem processes. My thesis examines the impacts of Gambusia and a similar sized native fish (Hypseleotris spp.) in the hydrologically and seasonally dynamic floodplain wetlands along the Ovens River in south-eastern Australia, where these species commonly co-occur. These wetlands systems typically undergo seasonal flooding during spring, but contract during summer, giving rise to high fish population densities, and potentially intensified biotic interactions. Gambusia and Hypseleotris population dynamics were monitored bi-monthly in 15 wetland pools over 2.5 years (2007-09) to determine if local seasonal habitat conditions, including floods and drying, influenced coexistence (Chapter Two). In two of these pools, I tested the degree of dietary overlap between Gambusia and Hypseleotris by examining fish gut contents and carrying out seasonal stable carbon (δ13C) and nitrogen (δ15N) isotope analysis of fish and invertebrate communities (2008-2009) (Chapter Three). I then experimentally compared the ability of the two fish to trigger trophic cascades in a year-long mesocosm experiment (2009-10). This monitored the top-down effects of Gambusia and Hypseleotris on invertebrates, algae and nutrients. Treatments included Gambusia only, Hypseleotris only, mixed-predator (Gambusia/Hypseleotris) and controls (no fish) (Chapter Four). A second experiment examined the effects of the same treatments under seasonal habitat contraction (April-July 2010) (Chapter Five). I found that hydrological disturbance, and Gambusia’s and Hypseleotris’ different breeding strategies, may facilitate coexistence. While these species coexisted year around, Gambusia’s ability to breed viviparously through an extended period of the year may have allowed it to increase numbers in the absence of potentially population-limiting floods. Gambusia and Hypseleotris had similar trophic positions but their dietary overlap was temporally dynamic, with Gambusia appearing to shift towards preying more broadly on consumers of a range of basal resources in winter. Despite Gambusia’s documented ability to facilitate trophic cascades, the indirect effect of the two species on algal biomass was weak and generally similar, but varied seasonally. Seasonal shifts in algal biomass and the presence of a predator appeared more important in facilitating trophic cascades than predator species. In autumn and winter, trophic cascades induced by both species occurred only when habitats were contracted, highlighting the important role that the spatial and seasonal dynamics of habitats can have in determining the trophic dynamics of both native and invasive species. In summary, despite previously reported strong top-down effects, Gambusia invasion may only alter prey communities at certain times of year and given particular ecological conditions in dynamic floodplain wetland pools where Hypseleotris is already present. Despite being taxonomically unrelated and differing in life history traits, Gambusia and Hypseleotris appear to have strong dietary overlap and largely equivalent weak and seasonally variable top-down effects, showing the potential for the impacts of invasive species to be moderated by local conditions and interactions with native species

Comparative food web impacts of a native and an invasive fish in dynamic floodplain wetlands

Invasive species cause major declines in biodiversity globally through a range of mechanisms including predation, displacement of endemic taxa, and complex food web impacts. While the dramatic effects of invaders have been well documented, less is known about cases where global invaders and native species coexist, the factors that facilitate this, and the comparative food web effects of invasive and native competitors. The invasive poeciliid fish Gambusia holbrooki (Eastern Mosquitofish) has been shown to have dramatic impacts on freshwater systems on four continents. These include trophic cascades resulting in algal blooms, changes in invertebrate community composition, and displacement of endemic fish and frogs. However in some situations they coexist with other fish species, with apparently only minor effects on native biodiversity and ecosystem processes. My thesis examines the impacts of Gambusia and a similar sized native fish (Hypseleotris spp.) in the hydrologically and seasonally dynamic floodplain wetlands along the Ovens River in south-eastern Australia, where these species commonly co-occur. These wetlands systems typically undergo seasonal flooding during spring, but contract during summer, giving rise to high fish population densities, and potentially intensified biotic interactions. Gambusia and Hypseleotris population dynamics were monitored bi-monthly in 15 wetland pools over 2.5 years (2007-09) to determine if local seasonal habitat conditions, including floods and drying, influenced coexistence (Chapter Two). In two of these pools, I tested the degree of dietary overlap between Gambusia and Hypseleotris by examining fish gut contents and carrying out seasonal stable carbon (δ13C) and nitrogen (δ15N) isotope analysis of fish and invertebrate communities (2008-2009) (Chapter Three). I then experimentally compared the ability of the two fish to trigger trophic cascades in a year-long mesocosm experiment (2009-10). This monitored the top-down effects of Gambusia and Hypseleotris on invertebrates, algae and nutrients. Treatments included Gambusia only, Hypseleotris only, mixed-predator (Gambusia/Hypseleotris) and controls (no fish) (Chapter Four). A second experiment examined the effects of the same treatments under seasonal habitat contraction (April-July 2010) (Chapter Five). I found that hydrological disturbance, and Gambusia’s and Hypseleotris’ different breeding strategies, may facilitate coexistence. While these species coexisted year around, Gambusia’s ability to breed viviparously through an extended period of the year may have allowed it to increase numbers in the absence of potentially population-limiting floods. Gambusia and Hypseleotris had similar trophic positions but their dietary overlap was temporally dynamic, with Gambusia appearing to shift towards preying more broadly on consumers of a range of basal resources in winter. Despite Gambusia’s documented ability to facilitate trophic cascades, the indirect effect of the two species on algal biomass was weak and generally similar, but varied seasonally. Seasonal shifts in algal biomass and the presence of a predator appeared more important in facilitating trophic cascades than predator species. In autumn and winter, trophic cascades induced by both species occurred only when habitats were contracted, highlighting the important role that the spatial and seasonal dynamics of habitats can have in determining the trophic dynamics of both native and invasive species. In summary, despite previously reported strong top-down effects, Gambusia invasion may only alter prey communities at certain times of year and given particular ecological conditions in dynamic floodplain wetland pools where Hypseleotris is already present. Despite being taxonomically unrelated and differing in life history traits, Gambusia and Hypseleotris appear to have strong dietary overlap and largely equivalent weak and seasonally variable top-down effects, showing the potential for the impacts of invasive species to be moderated by local conditions and interactions with native species

Ecological effects of extreme climatic events on riverine ecosystems:insights from Australia

Climate extremes and their physical impacts - including droughts, fires, floods, heat waves, storm surges and tropical cyclones - are important structuring forces in riverine ecosystems. Climate change is expected to increase the future occurrence of extremes, with potentially devastating effects on rivers and streams. We synthesise knowledge of extremes and their impacts on riverine ecosystems in Australia, a country for which projected changes in event characteristics reflect global trends. Hydrologic extremes play a major structuring role in river ecology across Australia. Droughts alter water quality and reduce habitat availability, driving organisms to refugia. Extreme floods increase hydrological connectivity and trigger booms in productivity, but can also alter channel morphology and cause disturbances such as hypoxic blackwater events. Tropical cyclones and post-cyclonic floods damage riparian vegetation, erode stream banks and alter water quality. Cyclone-induced delivery of large woody debris provides important instream habitat, although the wider ecological consequences of tropical cyclones are uncertain. Wildfires destroy catchment vegetation and expose soils, increasing inputs of fine sediment and nutrients to streams, particularly when followed by heavy rains. Research on the impacts of heat waves and storm surges is scarce, but data on temperature and salinity tolerances, respectively, may provide some insight into ecological responses. We identify research gaps and hypotheses to guide future research on the ecology of extreme climate events in Australia and beyond. A range of phenomenological, experimental and modelling approaches is needed to develop a mechanistic understanding of the ecological impact of extreme events and inform prediction of responses to future change.19 page(s

Benefits of permanent adoption of virtual conferences for conservation science

Disruptive events can trigger societal transformations with beneficial outcomes (Walker et al., 2020). For scientific professions, the COVID-19 pandemic triggered a comprehensive shift from in-person workshops, seminars, and conferences to the use of virtual formats for research and knowledge dissemination (e.g., Viglione, 2020). Despite the merits of virtual conferencing being advocated since the development of the internet (e.g., Reay, 2003; Gichora et al., 2010; Blackman et al., 2020), ecological and environmental sciences have historically relied on in-person events, and adoption of virtual conferencing for knowledge sharing and networking during so-called lockdowns and travel restrictions represented a radical change. Compelled by COVID-19, many conferences rapidly shifted to virtual formats. However, the combination of professional and personal attachment to in-person conferences, hopes of the effectiveness of vaccines against COVID-19, and organizations planning to host solely in-person events as soon as possible suggests we risk missing an unparalleled opportunity to permanently reimagine scientific conferences to benefit the practice and culture of conservation research