979 research outputs found

    Establishing microbial baselines to identify indicators of coral reef health

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    Microorganisms make a significant contribution to reef ecosystem health and resilience via their critical role in mediating nutrient transformations, their interactions with macro-organisms and their provision of chemical cues that underpin the recruitment of diverse reef taxa. However, environmental changes often cause compositional and functional shifts in microbial communities that can have flow-on consequences for microbial-mediated processes. These microbial alterations may impact the health of specific host organisms and can have repercussions for the functioning of entire coral ecosystems. Assessing changes in reef microbial communities should therefore provide an early indicator of ecosystem impacts and would underpin the development of diagnostic tools that could help forecast shifts in coral reef health under different environmental states. Monitoring, management and active restoration efforts have recently intensified and diversified in response to global declines in coral reef health. Here we propose that regular monitoring of coral reef microorganisms could provide a rapid and sensitive platform for identifying declining ecosystem health that can complement existing management frameworks. By summarising the most common threats to coral reefs, with a particular focus on the Great Barrier Reef, and elaborating on the role of microbes in coral reef health and ecosystem stability, we highlight the diagnostic applicability of microbes in reef management programs. Fundamental to this objective is the establishment of microbial baselines for Australia's coral reefs.AIMS@JCU PhD Scholarship; GBRMPA Science Management Research Award; Advance Queensland PhD Scholarship; Portuguese Science and Technology Foundation (FCT) [SFRH/BPD/110285/2015

    Eutrophication has no short-term effect on the Cymbastela stipitata holobiont

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    Levels of nitrogen in coastal areas have been rapidly increasing due to accumulative inputs of sewage and terrigenous sediments carrying fertilizers. Sponges have an immense filtering capacity and may be directly impacted (positively or negatively) by elevated concentrations of nitrogen. Sponges also host a wide diversity of microbes involved in nitrogen metabolism, yet little is known about the effects of nitrogen loading on these symbiotic partnerships. Manipulative experiments were undertaken to examine the potential effects of excess nitrogen (up to 240 μM) on microbial symbiosis in the abundant sponge species Cymbastela stipitata. Microbial composition and activity were examined using 454-pyrotag sequencing of DNA- and RNA-derived samples. Despite the high levels of nitrogen exposure (up to 124-fold above ambient), sponges appeared visibly unaffected at all treatment concentrations. At the phylum level, the microbial community was consistent between all sponge samples regardless of nitrogen treatment, with Cyanobacteria and Thaumarchaeota being the dominant taxa. Higher microbial diversity was observed at the operational taxonomic units (OTU) level (97% sequence similarity), with only 40% of OTUs shared between samples from all treatments. However, a single cyanobacterial OTU dominated the community of all individuals (average 73.5%) and this OTU did not vary with nitrogen treatment. The conserved microbial community in all sponges irrespective of nitrogen treatment highlights the stability of the sponge-microbe relationship and indicates that the holobiont is resistant to short pulses of nitrogen at levels mimicking sewage effluent

    Comparative genome-centric analysis reveals seasonal variation in the function of coral reef microbiomes

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    Microbially mediated processes contribute to coral reef resilience yet, despite extensive characterisation of microbial community variation following environmental perturbation, the effect on microbiome function is poorly understood. We undertook metagenomic sequencing of sponge, macroalgae and seawater microbiomes from a macroalgae-dominated inshore coral reef to define their functional potential and evaluate seasonal shifts in microbially mediated processes. In total, 125 high-quality metagenome-assembled genomes were reconstructed, spanning 15 bacterial and 3 archaeal phyla. Multivariate analysis of the genomes relative abundance revealed changes in the functional potential of reef microbiomes in relation to seasonal environmental fluctuations (e.g. macroalgae biomass, temperature). For example, a shift from Alphaproteobacteria to Bacteroidota-dominated seawater microbiomes occurred during summer, resulting in an increased genomic potential to degrade macroalgal-derived polysaccharides. An 85% reduction of Chloroflexota was observed in the sponge microbiome during summer, with potential consequences for nutrition, waste product removal, and detoxification in the sponge holobiont. A shift in the Firmicutes:Bacteroidota ratio was detected on macroalgae over summer with potential implications for polysaccharide degradation in macroalgal microbiomes. These results highlight that seasonal shifts in the dominant microbial taxa alter the functional repertoire of host-associated and seawater microbiomes, and highlight how environmental perturbation can affect microbially mediated processes in coral reef ecosystems.Australian Government Department of Industry, Innovation and Science; Advance Queensland PhD Scholarship Great Barrier Reef Marine Park Authority Management Award National Environmental Science Program (NESP)info:eu-repo/semantics/publishedVersio

    Analysis of Storage Methods and Tarping Practices for Corn Stover Bales

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    In 2011 and 2012, Iowa State University conducted storage trials for large, rectangular corn stover bales to determine the most effective storage method for companies and farmers harvesting corn stover. Over 2000 bales were used for different storage trials, and five storage configurations were tested. Standard outdoor tarped and indoor stacks proved to be the most effective in preserving bale quality and limiting deterioration, with dry matter losses below 5% in 2012. Moisture content of the bales was studied by collecting pre and post-storage moisture contents of the bales. It was found that all bales, no matter the initial moisture content, would dry down to an industrial-acceptable moisture content of nearly 15%, if stored appropriately. Bale temperatures, which are an indicator of moisture content and microbial activity, were also studied to support the dry matter loss and moisture content data, as well as to ensure these stacks were not creating opportunities for bales to self-combust. In both years of temperature studies, no bales were found to reach temperatures near self-combustion level

    The development of a national salt reduction strategy for Australia

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    Excess dietary salt is a well established cause of high blood pressure and vascular disease. National and international bodies recommend a significant reduction in population salt intakes on the basis of strong evidence for health gains that population salt reduction strategies could achieve. The Australian Division of World Action on Salt and Health (AWASH) coordinates the Drop the Salt! campaign in Australia. This aims to reduce the average amount of salt consumed by Australians to six grams per day over five years through three main implementation strategies targeting the food industry, the media and government. This strategy has the potential to achieve a rapid and significant reduction in dietary salt consumption in Australia. With industry and government engagement, this promises to be a highly effective, low cost option for preventing chronic disease.<br /

    Variability in Microbial Community Composition and Function Between Different Niches Within a Coral Reef

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    To explore how microbial community composition and function varies within a coral reef ecosystem, we performed metagenomic sequencing of seawater from four niches across Heron Island Reef, within the Great Barrier Reef. Metagenomes were sequenced from seawater samples associated with (1) the surface of the coral species Acropora palifera, (2) the surface of the coral species Acropora aspera, (3) the sandy substrate within the reef lagoon and (4) open water, outside of the reef crest. Microbial composition and metabolic function differed substantially between the four niches. The taxonomic profile showed a clear shift from an oligotroph-dominated community (e.g. SAR11, Prochlorococcus, Synechococcus) in the open water and sandy substrate niches, to a community characterised by an increased frequency of copiotrophic bacteria (e.g. Vibrio, Pseudoalteromonas, Alteromonas) in the coral seawater niches. The metabolic potential of the four microbial assemblages also displayed significant differences, with the open water and sandy substrate niches dominated by genes associated with core house-keeping processes such as amino acid, carbohydrate and protein metabolism as well as DNA and RNA synthesis and metabolism. In contrast, the coral surface seawater metagenomes had an enhanced frequency of genes associated with dynamic processes including motility and chemotaxis, regulation and cell signalling. These findings demonstrate that the composition and function of microbial communities are highly variable between niches within coral reef ecosystems and that coral reefs host heterogeneous microbial communities that are likely shaped by habitat structure, presence of animal hosts and local biogeochemical conditions.Human Frontier Science Program (Strasbourg, France) (Grant RGY0089/2011

    Demanding More: 4-H’s Diversity and Inclusion Efforts Are Simply Not Enough

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    Several youth organizations, such as 4-H, are reaffirming their commitment to diversity and inclusion in the workplace due to social and political events in 2020. Despite the national reckoning around civil rights, the author argues that racial and ethnic minorities are still not fully integrated into the 4-H culture. Addressing inclusion presents challenges; however, these can be better addressed when individuals realize the difficult conversations and actions needed to evoke change. The article concludes with a set of action items for the 4-H system, which focuses on investments, accountability, recognition, and transparency

    Incorporating Service Learning and Extension in Inner City Middle Schools: A Model for Future Programming

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    The article describes a program model used to promote science-based learning through a service learning model in an inner city school. Through working collaboratively with Extension staff, a program was created to meet the growing academic and social needs of youth in the inner city school system. If greater emphasis is placed on programming efforts among Extension, the community, and public schools, successful programs can be created to enhance the learning of the inner city youth population

    4-H and Its Relevance in the Era of #Moments in Urban Communities

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    Meeting the needs of today\u27s urban youth requires a shift in how organizations work with and view this socially driven population. National youth organizations, such as 4-H, must reposition themselves to remain relevant and relative to this ever-changing group. This repositioning requires the development of more culturally relevant programming and training and a keener eye toward how to reach and keep engaged these youth and their communities
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