Thermally Primed Seeds Exhibit Higher Germination Rates Than Those From Ambient Conditions.

Seagrasses provide critical ecosystem services such as carbon sequestration, sediment stabilisation and nursery habitat for juvenile fish. is ubiquitous within Australian and New Zealand estuaries, however, as a species is relatively understudied. We sourced seeds from a thermally affected east Australian estuary and investigated whether germination rates differed between ambient and thermally affected seeds over a variety of temperatures (16°C-28°C) to determine how seagrass systems might react in a warming climate.

Spatial and environmental drivers of temperate estuarine archaeal communities.

Archaea play a crucial role in the global biogeochemical cycling of elements and nutrients, helping to maintain the functional stability of estuarine systems. This study characterised the abundance and diversity of archaeal communities and identified the environmental conditions shaping these microbial communities within six temperate estuaries along approximately 500 km of the New South Wales coastline, Australia. Estuarine sediments were found to exhibit significantly higher species richness than planktonic communities, with representative sequences from the Crenarchaeota phylum characterising each environment.

Urbanisation and boating are the main contributors to underwater soundscapes in three temperate estuaries.

Anthropogenic noise has been identified as one of the most harmful forms of global pollutants impacting both terrestrial and aquatic ecosystems. As global populations continue to increase, coastlines are seeing substantial increases in the level of urbanisation. Although measures are in place to minimise stress on fauna, they rarely consider the impact of anthropogenic noise.

Spatial patterns in host-associated and free-living bacterial communities across six temperate estuaries.

A major goal of microbial ecology is to establish the importance of spatial and environmental factors in driving community variation. Their relative importance likely varies across spatial scales, but focus has primarily been on free-living communities within well-connected aquatic environments rather than less connected island-like habitats such as estuaries, and key host-associated communities within these systems. Here we sampled both free-living (seawater and sediment) and host-associated (estuarine fish hindgut microbiome, Pelates sexlineatus) communities across six temperate Australian estuaries spanning ∼500 km.

Gut microbial communities of hybridising pygmy angelfishes reflect species boundaries.

Hybridisation and introgression of eukaryotic genomes can generate new species or subsume existing ones, with direct and indirect consequences for biodiversity. An understudied component of these evolutionary forces is their potentially rapid effect on host gut microbiomes, and whether these pliable microcosms may serve as early biological indicators of speciation. We address this hypothesis in a field study of angelfishes (genus Centropyge), which have one of the highest prevalence of hybridisation within coral reef fish.

eDNA metabarcoding reveals shifts in sediment eukaryote communities in a metal contaminated estuary.

Metal contamination is a global issue impacting biodiversity in urbanised estuaries. Traditional methods to assess biodiversity are time consuming, costly and often exclude small or cryptic organisms due to difficulties with morphological identification. Metabarcoding approaches have been increasingly recognised for their utility in monitoring, however studies have focused on freshwater and marine systems despite the ecological significance of estuaries.

Non-lethal sampling does not misrepresent trophic level or dietary sources for Sagmariasus verreauxi (eastern rock lobster).

Rationale: Isotope analysis can be used to investigate the diets of predators based on assimilation of nitrogen and carbon isotopes from prey. Recent work has shown that tissues taken from legs, antennae or abdomen of lobsters can give different indications of diet, but this has never been evaluated for Sagmariasus verreauxi (eastern rock lobster). Work is now needed to prevent erroneous conclusions being drawn about lobster food webs, and undertaking this work could lead to developing non-lethal sampling methodologies.

Legacy metal contamination is reflected in the fish gut microbiome in an urbanised estuary.

Estuaries are critical habitats subject to a range of stressors requiring effective management. Microbes are gaining recognition as effective environmental indicators, however, the response of host associated communities to stressors remains poorly understood. We examined microbial communities from seawater, sediments and the estuarine fish Pelates sexlineatus, in Australia's largest urbanised estuary, and hypothesised that anthropogenic contamination would be reflected in the microbiology of these sample types.

Tracking the impacts of nutrient inputs on estuary ecosystem function.

Estuaries are one of the most impacted coastal environments globally, subjected to multiple stressors from urban, industry and coastal development. With increasing anthropogenic activity surrounding estuarine systems, sewage inputs have become a common concern. Stable isotope analysis provides a well-established tool to investigate the incorporation of nitrogen into marine organisms and identify major nutrient sources.

Insights into the Cultured Bacterial Fraction of Corals.

Bacteria associated with coral hosts are diverse and abundant, with recent studies suggesting involvement of these symbionts in host resilience to anthropogenic stress. Despite their putative importance, the work dedicated to culturing coral-associated bacteria has received little attention. Combining published and unpublished data, here we report a comprehensive overview of the diversity and function of culturable bacteria isolated from corals originating from tropical, temperate, and cold-water habitats.

The surface bacterial community of an Australian kelp shows cross-continental variation and relative stability within regions.

Epiphytic microbial communities often have a close relationship with their eukaryotic host, assisting with defence, health, disease prevention and nutrient transfer. Shifts in the structure of microbial communities could therefore have negative effects on the individual host and indirectly impact the surrounding ecosystem, particularly for major habitat-forming hosts, such as kelps in temperate rocky shores. Thus, an understanding of the structure and dynamics of host-associated microbial communities is essential for monitoring and assessing ecosystem changes.

Formation and Function of the Primary Tube During Settlement and Metamorphosis of the Marine Polychaete (Haswell, 1883) (Serpulidae).

AbstractThe serpulid polychaete has emerged as a major model organism for studies of marine invertebrate settlement and metamorphosis and for processes involved in marine biofouling. Rapid secretion of an enveloping, membranous, organic primary tube provides settling larvae of firm adhesion to a surface and a refuge within which to complete metamorphosis. While this tube is never calcified, it forms the template from which the calcified tube is produced at its anterior end.

A horizon scan of priorities for coastal marine microbiome research.

Research into the microbiomes of natural environments is changing the way ecologists and evolutionary biologists view the importance of microorganisms in ecosystem function. This is particularly relevant in ocean environments, where microorganisms constitute the majority of biomass and control most of the major biogeochemical cycles, including those that regulate Earth's climate. Coastal marine environments provide goods and services that are imperative to human survival and well-being (for example, fisheries and water purification), and emerging evidence indicates that these ecosystem services often depend on complex relationships between communities of microorganisms (the 'microbiome') and the environment or their hosts - termed the 'holobiont'.

Establishment of Coral-Bacteria Symbioses Reveal Changes in the Core Bacterial Community With Host Ontogeny.

Bacterial communities are fundamental symbionts of corals. However, the process by which bacterial communities are acquired across the life history of corals, particularly in larval and early juvenile stages, is still poorly characterized. Here, transfer of bacteria of the Scleractinian coral from adults to spawned egg-sperm bundles was analyzed, as well as acquisition across early developmental stages (larvae and newly settled spat), and 6-month-old juveniles.

Global Networks of Symbiodinium-Bacteria Within the Coral Holobiont.

Scleractinian corals form the framework of coral reefs and host abundant and diverse microbial communities that are fundamental to their success. A very limited number of studies have examined the co-occurrence of multiple partners within the coral 'holobiont' and their pattern of specificity over different geographical scales. In this study, we explored two molecular sequence datasets representing associations between corals and dinoflagellates in the genus Symbiodinium and between corals and bacteria, across the globe.

The Microbiome of the Gastrointestinal Tract of a Range-Shifting Marine Herbivorous Fish.

Globally, marine species' distributions are being modified due to rising ocean temperatures. Increasing evidence suggests a circum-global pattern of poleward extensions in the distributions of many tropical herbivorous species, including the ecologically important rabbitfish . Adaptability of a species to such new environments may be heavily influenced by the composition of their gastrointestinal microbe fauna, which is fundamentally important to animal health.

Bacterial and ciliate biofilm community structure at different spatial levels of a salt lake meta-community.

Meta-communities are assembled along an ecological scale that determines local and regional diversity. Spatial patterns have been detected in planktonic bacterial communities at distances <20 m, but little is known about the occurrence of similar variation for other microbial groups and changes in microbial meta-community assembly at different levels of a meta-community. To examine this variation, the biofilm of eight saline ponds were used to investigate processes shaping diversity within ponds (β) and between ponds (δ).

Coral microbiome database: Integration of sequences reveals high diversity and relatedness of coral-associated microbes.

Coral-associated microorganisms are thought to play a fundamental role in the health and ecology of corals, but understanding of specific coral-microbial interactions are lacking. In order to create a framework to examine coral-microbial specificity, we integrated and phylogenetically compared 21,100 SSU rRNA gene Sanger-produced sequences from bacteria and archaea associated with corals from previous studies, and accompanying host, location and publication metadata, to produce the Coral Microbiome Database. From this database, we identified 39 described and candidate phyla of Bacteria and two Archaea phyla associated with corals, demonstrating that corals are one of the most phylogenetically diverse animal microbiomes.

Future warming and acidification result in multiple ecological impacts to a temperate coralline alga.

Coralline algae are a crucial component of reef systems, stabilising reef substrate, providing habitat and contributing to accretion. Coralline algae and their surface microbial biofilms are also important as settlement cues for marine invertebrates, yet few studies address the impact of future environmental conditions on interactions between coralline algae, reef microbes and settlement by larvae of marine invertebrates. We exposed the temperate coralline algal species Amphiroa gracilis to warming and/or acidification scenarios for 21 days.

Ecosystem biomonitoring with eDNA: metabarcoding across the tree of life in a tropical marine environment.

Effective marine management requires comprehensive data on the status of marine biodiversity. However, efficient methods that can document biodiversity in our oceans are currently lacking. Environmental DNA (eDNA) sourced from seawater offers a new avenue for investigating the biota in marine ecosystems.

Bacterioplankton assemblages in coastal ponds reflect the influence of hydrology and geomorphological setting.

The factors that shape microbial community assembly in aquatic ecosystems have been widely studied; yet it is still unclear how distinct communities within a connected landscape influence one another. Coastal lakes are recipients of, and thus are connected to, both marine and terrestrial environments. Thus, they may host microbial assemblages that reflect the relative degree of influence by, and connectivity to, either system.

Future climate change scenarios differentially affect three abundant algal species in southwestern Australia.

Three species of macroalgae (Ecklonia radiata, Sargassum linearifolium, and Laurencia brongniartii) were subjected to future climate change conditions, tested directly for changes in their physiology and chemical ecology, and used in feeding assays with local herbivores to identify the indirect effects of climatic stressors on subsequent levels of herbivory. Each alga had distinct physical and chemical responses to the changes in environmental conditions. In high temperature conditions, S.

Coastal connectivity and spatial subsidy from a microbial perspective.

The transfer of organic material from one coastal environment to another can increase production in recipient habitats in a process known as spatial subsidy. Microorganisms drive the generation, transformation, and uptake of organic material in shallow coastal environments, but their significance in connecting coastal habitats through spatial subsidies has received limited attention. We address this by presenting a conceptual model of coastal connectivity that focuses on the flow of microbially mediated organic material in key coastal habitats.

Coastal bacterioplankton community dynamics in response to a natural disturbance.

In order to characterize how disturbances to microbial communities are propagated over temporal and spatial scales in aquatic environments, the dynamics of bacterial assemblages throughout a subtropical coastal embayment were investigated via SSU rRNA gene analyses over an 8-month period, which encompassed a large storm event. During non-perturbed conditions, sampling sites clustered into three groups based on their microbial community composition: an offshore oceanic group, a freshwater group, and a distinct and persistent coastal group. Significant differences in measured environmental parameters or in the bacterial community due to the storm event were found only within the coastal cluster of sampling sites, and only at 5 of 12 locations; three of these sites showed a significant response in both environmental and bacterial community characteristics.