ORCID Profile
0000-0002-1781-0726
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Microbiology | Microbial Ecology | Marine and Estuarine Ecology (incl. Marine Ichthyology) | Ecology | Marine And Estuarine Ecology (Incl. Marine Ichthyology) | Microbial Ecology | Biological Oceanography | Global Change Biology | Global Change Biology | Phycology (incl. Marine Grasses) | Biological And Medical Chemistry | Oceanography | Chemical Oceanography | Environmental Management And Rehabilitation | Other Chemical Sciences | Industrial Biotechnology | Cell Metabolism | Bacteriology | Environmental Impact Assessment | Environmental Chemistry (incl. Atmospheric Chemistry) | Fisheries Management | Microbial Genetics | Environmental Monitoring | Microbial Systematics, Taxonomy And Phylogeny | Environmental Rehabilitation (excl. Bioremediation) | Life Histories (Incl. Population Ecology) | Physical Sciences not elsewhere classified | Environmental Science and Management | Endocrinology | Ecological Applications | Environmental Technologies | Biological Oceanography | Ecological Impacts of Climate Change | Phycology | Bioprocessing, Bioproduction and Bioproducts |
ANZSRC Socio-Economic Objective (SEO)
Marine Flora, Fauna and Biodiversity | Biological sciences | Ecosystem Assessment and Management of Coastal and Estuarine Environments | Living resources (incl. impacts of fishing on non-target species) | Treatments (e.g. chemicals, antibiotics) | Control of Animal Pests, Diseases and Exotic Species in Coastal and Estuarine Environments | Integrated (ecosystem) assessment and management | Climate change | Control of pests and exotic species | Ecosystem Adaptation to Climate Change | Effects of Climate Change and Variability on Australia (excl. Social Impacts) | Living resources (flora and fauna) | Coastal and Estuarine Flora, Fauna and Biodiversity | Coal | Physical and chemical conditions | Oceanic processes (excl. climate related) | Fisheries - Wild Caught not elsewhere classified | Physical and Chemical Conditions of Water in Coastal and Estuarine Environments | Rights to Environmental and Natural Resources (excl. Water Allocation) | Coastal and Marine Management Policy | Coal—conversion to liquid fuels | Infectious diseases | Endocrine organs and diseases (incl. diabetes) | Industrial/degraded areas | Physical and chemical conditions | Rehabilitation of Degraded Coastal and Estuarine Environments | Expanding Knowledge in the Biological Sciences | Treatments (e.g. chemicals, antibiotics) | Ecosystem Assessment and Management of Marine Environments | Coastal and Estuarine Water Management
Related Links
Publications
The future of management programmes for heart failure
Publisher: Elsevier BV
Date: 09-2008
Kelp Forest Restoration in Australia
Publisher: Frontiers Media SA
Date: 14-02-2020
Genomes and Virulence Factors of Novel Bacterial Pathogens Causing Bleaching Disease in the Marine Red Alga Delisea pulchra
Publisher: Public Library of Science (PLoS)
Date: 05-12-2011
Induction of Larval Metamorphosis of the Coral Acropora millepora by Tetrabromopyrrole Isolated from a Pseudoalteromonas Bacterium
Publisher: Public Library of Science (PLoS)
Date: 29-04-2011
The application of zeta diversity as a continuous measure of compositional change in ecology
Publisher: Cold Spring Harbor Laboratory
Date: 09-11-2017
DOI: 10.1101/216580
Abstract: Zeta ersity provides the average number of shared species across n sites (or shared operational taxonomic units (OTUs) across n cases). It quantifies the variation in species composition of multiple assemblages in space and time to capture the contribution of the full suite of narrow, intermediate and wide-ranging species to biotic heterogeneity. Zeta ersity was proposed for measuring compositional turnover in plant and animal assemblages, but is equally relevant for application to any biological system that can be characterised by a row by column incidence matrix. Here we illustrate the application of zeta ersity to explore compositional change in empirical data, and how observed patterns may be interpreted. We use 10 datasets from a broad range of scales and levels of biological organisation – from DNA molecules to microbes, plants and birds – including one of the original data sets used by R.H. Whittaker in the 1960’s to express compositional change and distance decay using beta ersity. The applications show (i) how different s ling schemes used during the calculation of zeta ersity may be appropriate for different data types and ecological questions, (ii) how higher orders of zeta may in some cases better detect shifts, transitions or periodicity, and importantly (iii) the relative roles of rare versus common species in driving patterns of compositional change. By exploring the application of zeta ersity across this broad range of contexts, our goal is to demonstrate its value as a tool for understanding continuous bio ersity turnover and as a metric for filling the empirical gap that exists on spatial or temporal change in compositional ersity.
Fitness benefits of size-dependent diet switching in a marine herbivore
Publisher: Springer Science and Business Media LLC
Date: 19-01-2012
In situ quantification of a natural settlement cue and recruitment of the Australian sea urchin Holopneustes purpurascens
Publisher: Inter-Research Science Center
Date: 22-05-2006
DOI: 10.3354/MEPS314001
Reinvestigation of the sulfuric acid-catalysed cyclisation of brominated 2-alkyllevulinic acids to 3-alkyl-5-methylene-2(5H)-furanones
Publisher: Elsevier BV
Date: 11-1997
Sea temperature and habitat effects on juvenile reef fishes along a tropicalizing coastline
Publisher: Wiley
Date: 04-2022
DOI: 10.1111/DDI.13484
Abstract: Temperate marine systems globally are warming at accelerating rates, facilitating the poleward movement of warm‐water species, which are tropicalizing higher‐latitude reefs. While temperature plays a key role in structuring species distributions, less is known about how species’ early life stages are responding to warming‐induced changes in preferred nursery habitat availability. We aim to identify key ecological and environmental drivers of juvenile reef fishes’ distributions in the context of ocean warming. South‐eastern Australian coastline from 30 to 37°S. We used a decade of underwater visual census data to uncover latitudinal distribution patterns of juvenile reef fishes and habitats across 1000 km of coastline, from subtropical to temperate latitudes. We modelled how benthic habitat cover, depth, wave exposure and sea surface temperature influence distributions of warm‐water and cool‐water juvenile reef fishes on temperate rocky reefs. We found sea surface temperature was typically the most important factor influencing densities of juvenile fishes, regardless of species’ thermal affinity or latitudinal range extent. Juveniles of tropical and subtropical range‐expanding fishes responded more strongly to warmer temperatures and lower wave exposure, while juveniles of temperate species responded more strongly to benthic habitats. Species’ responses to greater availability of temperate reef habitat‐formers such as kelp and other macroalgae contrasted, being positive for temperate and negative for tropical and subtropical juvenile fishes. The availability of both suitable habitat and sea temperatures for species’ early life stages is important considerations when predicting changes in reef fishes’ distributions in the context of ocean warming. Warming‐induced isotherm shifts and feedback loops constraining the persistence of key temperate reef habitat‐formers will favour range‐expanding tropical reef fishes colonizing higher‐latitude reefs, while disadvantaging some macroalgal‐associated resident temperate species. Such varying responses to warming‐induced environmental changes may strongly influence the structure of emerging tropicalized reef assemblages.
Biofilms: an emergent form of bacterial life
Publisher: Springer Science and Business Media LLC
Date: 11-08-2016
Abstract: Bacterial biofilms are formed by communities that are embedded in a self-produced matrix of extracellular polymeric substances (EPS). Importantly, bacteria in biofilms exhibit a set of 'emergent properties' that differ substantially from free-living bacterial cells. In this Review, we consider the fundamental role of the biofilm matrix in establishing the emergent properties of biofilms, describing how the characteristic features of biofilms - such as social cooperation, resource capture and enhanced survival of exposure to antimicrobials - all rely on the structural and functional properties of the matrix. Finally, we highlight the value of an ecological perspective in the study of the emergent properties of biofilms, which enables an appreciation of the ecological success of biofilms as habitat formers and, more generally, as a bacterial lifestyle.
Coastal urbanisation affects microbial communities on a dominant marine holobiont
Publisher: Springer Science and Business Media LLC
Date: 17-01-2018
DOI: 10.1038/S41522-017-0044-Z
Abstract: Host-associated microbial communities play a fundamental role in the life of eukaryotic hosts. It is increasingly argued that hosts and their microbiota must be studied together as 'holobionts' to better understand the effects of environmental stressors on host functioning. Disruptions of host–microbiota interactions by environmental stressors can negatively affect host performance and survival. Substantial ecological impacts are likely when the affected hosts are habitat-forming species (e.g., trees, kelps) that underpin local bio ersity. In marine systems, coastal urbanisation via the addition of artificial structures is a major source of stress to habitat formers, but its effect on their associated microbial communities is unknown. We characterised kelp-associated microbial communities in two of the most common and abundant artificial structures in Sydney Harbour—pier-pilings and seawalls—and in neighbouring natural rocky reefs. The kelp Ecklonia radiata is the dominant habitat-forming species along 8000 km of the temperate Australian coast. Kelp-associated microbial communities on pilings differed significantly from those on seawalls and natural rocky reefs, possibly due to differences in abiotic (e.g., shade) and biotic (e.g., grazing) factors between habitats. Many bacteria that were more abundant on kelp on pilings belonged to taxa often associated with macroalgal diseases, including tissue bleaching in Ecklonia . There were, however, no differences in kelp photosynthetic capacity between habitats. The observed differences in microbial communities may have negative effects on the host by promoting fouling by macroorganisms or by causing and spreading disease over time. This study demonstrates that urbanisation can alter the microbiota of key habitat-forming species with potential ecological consequences.
Contribution of horizontal gene transfer to the functionality of microbial biofilm on a macroalgae
Publisher: Springer Science and Business Media LLC
Date: 08-02-2021
Reduced performance of native infauna following recruitment to a habitat-forming invasive marine alga
Publisher: Springer Science and Business Media LLC
Date: 22-10-2008
DOI: 10.1007/S00442-008-1181-0
Abstract: Despite well-documented negative impacts of invasive species on native biota, evidence for the facilitation of native organisms, particularly by habitat-forming invasive species, is increasing. However, most of these studies are conducted at the population or community level, and we know little about the in idual fitness consequences of recruitment to habitat-forming invasive species and, consequently, whether recruitment to these habitats is adaptive. We determined the consequences of recruitment to the invasive green alga Caulerpa taxifolia on the native soft-sediment bivalve Anadara trapezia and nearby unvegetated sediment. Initially, we documented the growth and survivorship of A. trapezia following a natural recruitment event, to which recruitment to C. taxifolia was very high. After 12 months, few clams remained in either habitat, and those that remained showed little growth. Experimental manipulations of recruits demonstrated that all performance measures (survivorship, growth and condition) were significantly reduced in C. taxifolia sediments compared to unvegetated sediments. Exploration of potential mechanisms responsible for the reduced performance in C. taxifolia sediments showed that water flow and water column dissolved oxygen (DO) were significantly reduced under the canopy of C. taxifolia and that sediment anoxia was significantly higher and sediment sulphides greater in C. taxifolia sediments. However, phytoplankton abundance (an indicator of food supply) was significantly higher in C. taxifolia sediments than in unvegetated ones. Our results demonstrate that recruitment of native species to habitat-forming invasive species can reduce growth, condition and survivorship and that studies conducted at the community level may lead to erroneous conclusions about the impacts of invaders and should include studies on life-history traits, particularly juveniles.
Variation in the strength of continental boundary currents determines continent-wide connectivity in kelp
Publisher: Wiley
Date: 17-03-2011
CHEMICAL DEFENSE IN A MARINE ALGA: HERITABILITY AND THE POTENTIAL FOR SELECTION BY HERBIVORES
Publisher: Wiley
Date: 11-2004
DOI: 10.1890/03-4041
Dissolved histamine: a potential habitat marker promoting settlement and metamorphosis in sea urchin larvae
Publisher: Springer Science and Business Media LLC
Date: 18-01-2012
Surfactant enhanced lipase containing films characterized by confocal laser scanning microscopy
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.COLSURFB.2010.08.042
Abstract: Confocal laser scanning microscopy (CLSM) in combination with a fluorescently labeling enzyme dye, LavaPurple™, was demonstrated as a technique for the visualization of Thermomyces (Humicola) lanuginosa lipase (LIP(HLL)) and Candida antarctica lipase A (LIP(CA)) within a transparent latex coating. Addition of Teric Surfactants (C(16) non-ionic Teric 475, 1.8% (w/w) or C(10) non-ionic Teric 460, 2.0% (w/w)) significantly increased the accumulation of both LIP(HLL) and LIP(CA) to the surface of a latex coating. An α-naphthyl acetate substrate assay was used to quantify the accumulated lipase. The results derived from the acetate assay correlated with the enzyme accumulation (at the surface) observed in the CLSM images of the latex coating. This correlation demonstrated that the increased enzyme accumulation within the top 2μm of the latex film was responsible for the increase in surface enzymatic activity. The combination of CLSM imagery and quantifiable image analysis provided a valuable tool for the optimization of surfactant concentrations for maximizing the activity of an enzyme (and potentially other additives) within a latex coating.
The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts
Publisher: The Royal Society
Date: 22-08-2014
Abstract: Climate-driven changes in biotic interactions can profoundly alter ecological communities, particularly when they impact foundation species. In marine systems, changes in herbivory and the consequent loss of dominant habitat forming species can result in dramatic community phase shifts, such as from coral to macroalgal dominance when tropical fish herbivory decreases, and from algal forests to ‘barrens’ when temperate urchin grazing increases. Here, we propose a novel phase-shift away from macroalgal dominance caused by tropical herbivores extending their range into temperate regions. We argue that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas. Overgrazing of temperate macroalgae by tropical herbivorous fishes has already occurred in Japan and the Mediterranean. Emerging evidence suggests similar phenomena are occurring in other temperate regions, with increasing occurrence of tropical fishes on temperate reefs.
Towards Restoration of Missing Underwater Forests
Publisher: Public Library of Science (PLoS)
Date: 08-01-2014
Interfaces Between Bacterial and Eukaryotic Neuroecology
Publisher: Oxford University Press (OUP)
Date: 05-09-2011
DOI: 10.1093/ICB/ICR115
Abstract: The sensory capacity of bacteria and macroalgae (seaweeds) is limited with respect to many modalities (visual, auditory) common in "higher" organisms such as animals. Thus, we expect that other modalities, such as chemical signaling and sensing, would play particularly important roles in their sensory ecology. Here, we discuss two ex les of chemical signaling in bacteria and seaweeds: (1) the role of chemical defenses and quorum-sensing (QS) regulatory systems in bacterial colonization and infection of the red alga Delisea pulchra and their ecological consequences, and (2) the regulation of dispersal and differentiation by nitric oxide (NO) in bacterial biofilms. Consistent with the goals of neuroecology, in both cases, we investigate the links between specific signal-mediated molecular mechanisms, and ecological outcomes, for populations or assemblages of bacteria or seaweeds. We conclude by suggesting that because of the fundamental role played by chemical signaling in bacteria, bacterial systems, either by themselves or in interactions with other organisms, have much to offer for understanding general issues in neuroecology. Thus, further integration of microbiology with the biology of eukaryotes would seem warranted and is likely to prove illuminating.
Restore or Redefine: Future Trajectories for Restoration
Publisher: Frontiers Media SA
Date: 17-04-2020
CHEMICAL MEDIATION OF COLONIZATION OF SEAWEED SURFACES1
Publisher: Wiley
Date: 08-2002
Large-scale geographic variation in distribution and abundance of Australian deep-water kelp forests
Publisher: Public Library of Science (PLoS)
Date: 18-02-2015
Novel ssDNA Viruses Detected in the Virome of Bleached, Habitat-Forming Kelp Ecklonia radiata
Publisher: Frontiers Media SA
Date: 12-01-2018
A global approach to mapping the environmental risk of harbours on aquatic systems
Publisher: Elsevier BV
Date: 09-2020
Chemically mediated antifouling in the red alga Delisea pulchra
Publisher: Inter-Research Science Center
Date: 03-08-2006
DOI: 10.3354/MEPS318153
Grazing effects of the sea urchin Centrostephanus rodgersii in two contrasting rocky reef habitats: effects of urchin density and its implications for the fishery
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/MF03052
Abstract: The sea urchin Centrostephanus rodgersii plays an important role in determining the abundance and composition of benthic macroalgae in New South Wales. Centrostephanus rodgersii is commonly found in areas devoid of foliose algae (termed 'barrens habitat'), which abruptly change into areas rich in foliose algae (termed 'fringe habitat'). Complementary experiments were used to investigate the impact of C. rodgersii grazing on algal assemblages at a range of densities in the barrens and fringe habitats. Although 33% of the natural density of C.�rodgersii maintained barrens areas relatively free of foliose algae, only densities exceeding natural densities within barrens habitat cleared areas dominated by macroalgae. The impact of grazing was not linearly related to density in either habitat, which suggests that both the barrens and fringe habitats are stable and will persist unless there is a dramatic decrease in urchin densities in barrens areas or a large influx into fringe areas. These findings have significant implications for the commercial harvesting of C. rodgersii. They imply that reducing urchin densities in barrens habitats, or translocating urchins from barrens to fringe habitats in order to improve roe quality, will not significantly alter the algal assemblage of either habitat in the short term (less than 3 months).
Reproductive cycle of the sea urchin Holopneustes purpurascens (Temnopleuridae: Echinodermata)
Publisher: Springer Science and Business Media LLC
Date: 03-2002
Spatial compositional turnover varies with trophic level and body size in marine assemblages of micro‐ and macroorganisms
Publisher: Wiley
Date: 23-05-2022
DOI: 10.1111/GEB.13530
Abstract: Spatial compositional turnover varies considerably among co‐occurring assemblages of organisms, presumably shaped by common processes related to species traits. We investigated patterns of spatial turnover in a erse set of marine assemblages using zeta ersity, which extends traditional pairwise measures of turnover to capture the roles of both rare and common species in shaping assemblage turnover. We tested the generality of hypothesized patterns related to ecological traits and provide insights into mechanisms of bio ersity change. Temperate pelagic and benthic marine assemblages of micro‐ and macroorganisms along south‐eastern Australia (30–36° S latitude). 2008–2021. Bacteria, phytoplankton, zooplankton, fish, and macrobenthic groups. Six marine datasets spanning bacteria to fishes were collated for measures of “species” occurrence, with a 1° latitude grain. For each assemblage, ecological traits of body size, habitat and trophic level were analysed for the form and rate of decline in zeta ersity and for the species retention rate. Species at higher trophic levels showed two to three times the rate of zeta ersity decline compared with lower trophic levels, indicating an increase in turnover from phytoplankton to carnivorous fishes. Body size showed the hypothesized unimodal relationship with rates of turnover for macroorganisms. Patterns of bacterial turnover contrasted with those found for macroorganisms, with the highest levels of turnover in pelagic habitats compared with benthic (kelp‐associated) habitats. The shape of retention rate curves showed the importance of both rare and common species in driving turnover a finding that would not have been observable using pairwise (beta ersity) measures of turnover. Our results support theoretical predictions for phytoplankton and macroorganisms, showing an increase in turnover rate with trophic level, but these predictions did not hold for bacteria. Such deviations from theory need to be investigated further to identify underlying processes that govern microbial assemblage dynamics.
Community Structure and Functional Gene Profile of Bacteria on Healthy and Diseased Thalli of the Red Seaweed Delisea pulchra
Publisher: Public Library of Science (PLoS)
Date: 03-12-2012
Dynamics of algal secondary metabolites in two species of sea hare
Publisher: Springer Science and Business Media LLC
Date: 2000
Defining marine bacterioplankton community assembly rules by contrasting the importance of environmental determinants and biotic interactions
Publisher: Wiley
Date: 06-02-2023
Abstract: Bacterioplankton communities govern marine productivity and biogeochemical cycling, yet drivers of bacterioplankton assembly remain unclear. Here, we contrast the relative contribution of deterministic processes (environmental factors and biotic interactions) in driving temporal dynamics of bacterioplankton ersity at three different oceanographic time series locations, spanning 15° of latitude, which are each characterized by different environmental conditions and varying degrees of seasonality. Monthly surface s les (5.5 years) were analysed using 16S rRNA licon sequencing. The high‐ and mid‐latitude sites of Maria Island and Port Hacking were characterized by high and intermediate levels of environmental heterogeneity, respectively, with both alpha ersity (72% 24% of total variation) and beta ersity (32% 30%) patterns within bacterioplankton assemblages explained by day length, ammonium, and mixed layer depth. In contrast, North Stradbroke Island, a sub‐tropical location where environmental conditions are less variable, interspecific interactions were of increased importance in structuring bacterioplankton ersity (alpha: 33% beta: 26%) with environment only contributing 11% and 13% to predicting ersity, respectively. Our results demonstrate that bacterioplankton ersity is the result of both deterministic environmental and biotic processes and that the importance of these different deterministic processes varies, potential in response to environmental heterogeneity.
Sydney Harbour: What we do and do not know about a highly diverse estuary
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/MF15159
Abstract: Sydney Harbour is a global hotspot for marine and estuarine ersity. Despite its social, economic and biological value, the available knowledge has not previously been reviewed or synthesised. We systematically reviewed the published literature and consulted experts to establish our current understanding of the Harbour’s natural systems, identify knowledge gaps, and compare Sydney Harbour to other major estuaries worldwide. Of the 110 studies in our review, 81 focussed on ecology or biology, six on the chemistry, 10 on geology and 11 on oceanography. Subtidal rocky reef habitats were the most studied, with a focus on habitat forming macroalgae. In total 586 fish species have been recorded from the Harbour, which is high relative to other major estuaries worldwide. There has been a lack of process studies, and an almost complete absence of substantial time series that constrains our capacity to identify trends, environmental thresholds or major drivers of biotic interactions. We also highlight a lack of knowledge on the ecological functioning of Sydney Harbour, including studies on microbial communities. A sound understanding of the complexity, connectivity and dynamics underlying ecosystem functioning will allow further advances in management for the Harbour and for similarly modified estuaries around the world.
Surface chemistry versus whole-cell extracts: antifouling tests with seaweed metabolites
Publisher: Inter-Research Science Center
Date: 11-01-2007
DOI: 10.3354/MEPS329073
Inhibition of fouling by marine bacteria immobilised in κ-carrageenan beads
Publisher: Informa UK Limited
Date: 2007
DOI: 10.1080/08927010701366280
Abstract: Antifouling solutions that leave little or no impact in the world's oceans are constantly being sought. This study employed the immobilisation of the antifouling bacterium Pseudoalteromonas tunicata in kappa-carrageenan to demonstrate how a surface may be protected from fouling by bacteria, i.e. a 'living paint'. Attempts so far to produce a 'living paint' have been limited in both longevity of effectiveness and demonstration of applicability, most noticeably regarding the lack of any field data. Here survival of bacteria immobilised in kappa-carrageenan for 12 months in the laboratory is demonstrated and evidence presented for inhibition of fouling for up to 7 weeks in the field (Sydney Harbour, NSW, Australia).
Predation Response of Vibrio fischeri Biofilms to Bacterivorus Protists
Publisher: American Society for Microbiology
Date: 15-01-2013
DOI: 10.1128/AEM.02710-12
Abstract: Vibrio fischeri proliferates in a sessile, stable community known as a biofilm, which is one alternative survival strategy of its life cycle. Although this survival strategy provides adequate protection from abiotic factors, marine biofilms are still susceptible to grazing by bacteria-consuming protozoa. Subsequently, grazing pressure can be controlled by certain defense mechanisms that confer higher biofilm antipredator fitness. In the present work, we hypothesized that V. fischeri exhibits an antipredator fitness behavior while forming biofilms. Different predators representing commonly found species in aquatic populations were examined, including the flagellates Rhynchomonas nasuta and Neobodo designis (early biofilm feeders) and the ciliate Tetrahymena pyriformis (late biofilm grazer). V. fischeri biofilms included isolates from both seawater and squid hosts ( Euprymna and Sepiola species). Our results demonstrate inhibition of predation by biofilms, specifically, isolates from seawater. Additionally, antiprotozoan behavior was observed to be higher in late biofilms, particularly toward the ciliate T. pyriformis however, inhibitory effects were found to be widespread among all isolates tested. These results provide an alternative explanation for the adaptive advantage and persistence of V. fischeri biofilms and provide an important contribution to the understanding of defensive mechanisms that exist in the out-of-host environment.
Larval development and metamorphosis of the Australian diadematid sea urchinCentrostephanus rodgersii
Publisher: Informa UK Limited
Date: 2005
Simple Growth Patterns Can Create Complex Trajectories for the Ontogeny of Constitutive Chemical Defences in Seaweeds
Publisher: Public Library of Science (PLoS)
Date: 30-01-2014
Low Densities of Epiphytic Bacteria from the Marine Alga Ulva australis Inhibit Settlement of Fouling Organisms
Publisher: American Society for Microbiology
Date: 15-12-2007
DOI: 10.1128/AEM.01543-07
Abstract: Bacteria that produce inhibitory compounds on the surface of marine algae are thought to contribute to the defense of the host plant against colonization of fouling organisms. However, the number of bacterial cells necessary to defend against fouling on the plant surface is not known. Pseudoalteromonas tunicata and Phaeobacter sp. strain 2.10 (formerly Roseobacter gallaeciensis ) are marine bacteria often found in association with the alga Ulva australis and produce a range of extracellular inhibitory compounds against common fouling organisms. P. tunicata and Phaeobacter sp. strain 2.10 biofilms with cell densities ranging from 10 2 to 10 8 cells cm −2 were established on polystyrene petri dishes. Attachment and settlement assays were performed with marine fungi (uncharacterized isolates from U. australis ), marine bacteria ( Pseudoalteromonas gracilis , Alteromonas sp., and Cellulophaga fucicola ), invertebrate larvae ( Bugula neritina ), and algal spores ( Polysiphonia sp.) and gametes ( U. australis ). Remarkably low cell densities (10 2 to 10 3 cells cm −2 ) of P. tunicata were effective in preventing settlement of algal spores and marine fungi in petri dishes. P. tunicata also prevented settlement of invertebrate larvae at densities of 10 4 to 10 5 cells cm −2 . Similarly, low cell densities (10 3 to 10 4 cells cm −2 ) of Phaeobacter sp. strain 2.10 had antilarval and antibacterial activity. Previously, it has been shown that abundance of P. tunicata on marine eukaryotic hosts is low ( × 10 3 cells cm −2 ) (T. L. Skovhus et al., Appl. Environ. Microbiol. 70:2373-2382, 2004). Despite such low numbers of P. tunicata on U. australis in situ, our data suggest that P. tunicata and Phaeobacter sp. strain 2.10 are present in sufficient quantities on the plant to inhibit fouling organisms. This strongly supports the hypothesis that P. tunicata and Phaeobacter sp. strain 2.10 can play a role in defense against fouling on U. australis at cell densities that commonly occur in situ.
Eco-engineering of modified shorelines recovers wrack subsidies
Publisher: Elsevier BV
Date: 03-2018
Do marine natural products interfere with prokaryotic AHL regulatory systems?
Publisher: Inter-Research Science Center
Date: 1997
DOI: 10.3354/AME013085
Making seawalls multifunctional: The positive effects of seeded bivalves and habitat structure on species diversity and filtration rates
Publisher: Elsevier BV
Date: 03-2021
Micro-fabricated polydimethyl siloxane (PDMS) surfaces regulate the development of marine microbial biofilm communities
Publisher: Informa UK Limited
Date: 21-02-2014
DOI: 10.1080/08927014.2013.872778
Abstract: This study explored an antifouling (AF) concept based on deployment of microfabricated polydimethyl siloxane (PDMS) surfaces with 1-10 μm periodicity corrugated topographies in temperate marine waters. The effect of the surfaces on the development of microbial biofilms over 28 days and during different seasons, including both summer and winter, was examined using confocal laser scanning microscopy (CLSM) as well as terminal restriction fragment (T-RF) analysis for phylogenetic fingerprinting. The microscale topography significantly impacted biofilm development by altering the attachment pattern and reducing microcolony formation on the 1, 2 and 4 μm PDMS surfaces. Also, field deployments over 28 days showed a significant reduction in biovolume on the 4 and 10 μm PDMS surfaces despite altered environmental conditions. The microfabricated PDMS surfaces further significantly impacted on the community composition of the biofilms, as revealed by changes in T-RF profiles, at different stages of development. Moreover, altered biofilm resistance was demonstrated by exposing pre-established biofilms on 10 μm micro-fabricated surfaces to enhanced flagellate predation by a heterotrophic protist, Rhynchomonas nasuta. Pronounced changes in the overall marine microbial biofilm development as well as community composition warrant exploring substratum modification for marine AF applications.
Temperature induced bacterial virulence and bleaching disease in a chemically defended marine macroalga
Publisher: Wiley
Date: 15-10-2010
DOI: 10.1111/J.1462-2920.2010.02356.X
Abstract: Host-pathogen interactions have been widely studied in humans and terrestrial plants, but are much less well explored in marine systems. Here we show that a marine macroalga, Delisea pulchra, utilizes a chemical defence - furanones - to inhibit colonization and infection by a novel bacterial pathogen, Ruegeria sp. R11, and that infection by R11 is temperature dependent. Ruegeria sp. R11 formed biofilms, invaded and bleached furanone-free, but not furanone-producing D. pulchra thalli, at high (24°C) but not low (19°C) temperatures. Bleaching is commonly observed in natural populations of D. pulchra near Sydney, Australia, during the austral summer when ocean temperatures are at their peak and the chemical defences of the alga are reduced. Furanones, produced by D. pulchra as a chemical defence, inhibit quorum sensing (QS) in bacteria, and this may play a role in furanone inhibition of R11 infection of furanone-free thalli as R11 produces QS signals. This interplay between temperature, an algal chemical defence mechanism and bacterial virulence demonstrates the complex impact environmental change can have on an ecosystem.
Chemical mediation of coral larval settlement by crustose coralline algae
Publisher: Springer Science and Business Media LLC
Date: 04-06-2015
DOI: 10.1038/SREP10803
Abstract: The majority of marine invertebrates produce dispersive larvae which, in order to complete their life cycles, must attach and metamorphose into benthic forms. This process, collectively referred to as settlement, is often guided by habitat-specific cues. While the sources of such cues are well known, the links between their biological activity, chemical identity, presence and quantification in situ are largely missing. Previous work on coral larval settlement in vitro has shown widespread induction by crustose coralline algae (CCA) and in particular their associated bacteria. However, we found that bacterial biofilms on CCA did not initiate ecologically realistic settlement responses in larvae of 11 hard coral species from Australia, Guam, Singapore and Japan. We instead found that algal chemical cues induce identical behavioral responses of larvae as per live CCA. We identified two classes of CCA cell wall-associated compounds – glycoglycerolipids and polysaccharides – as the main constituents of settlement inducing fractions. These algae-derived fractions induce settlement and metamorphosis at equivalent concentrations as present in CCA, both in small scale laboratory assays and under flow-through conditions, suggesting their ability to act in an ecologically relevant fashion to steer larval settlement of corals. Both compound classes were readily detected in natural s les.
Functional genomic signatures of sponge bacteria reveal unique and shared features of symbiosis
Publisher: Springer Science and Business Media LLC
Date: 03-06-2010
Abstract: Sponges form close relationships with bacteria, and a remarkable phylogenetic ersity of yet-uncultured bacteria has been identified from sponges using molecular methods. In this study, we use a comparative metagenomic analysis of the bacterial community in the model sponge Cymbastela concentrica and in the surrounding seawater to identify previously unrecognized genomic signatures and functions for sponge bacteria. We observed a surprisingly large number of transposable insertion elements, a feature also observed in other symbiotic bacteria, as well as a set of predicted mechanisms that may defend the sponge community against the introduction of foreign DNA and hence contribute to its genetic resilience. Moreover, several shared metabolic interactions between bacteria and host include vitamin production, nutrient transport and utilization, and redox sensing and response. Finally, an abundance of protein-protein interactions mediated through ankyrin and tetratricopeptide repeat proteins could represent a mechanism for the sponge to discriminate between food and resident bacteria. These data provide new insight into the evolution of symbiotic ersity, microbial metabolism and host-microbe interactions in sponges.
Long-term empirical evidence of ocean warming leading to tropicalization of fish communities, increased herbivory, and loss of kelp
Publisher: Proceedings of the National Academy of Sciences
Date: 14-11-2016
Abstract: Most studies of the impact of global warming focus on the direct physiological impacts of climate change. However, global warming is shifting the distribution of many species and leading to novel interactions between previously separated species that have the potential to transform entire ecological communities. This study shows that an increase in the proportion of warmwater species (“tropicalization”) as oceans warm is increasing fish herbivory in kelp forests, contributing to their decline and subsequent persistence in alternate “kelp-free” states. These tropical and subtropical herbivores are increasingly impacting temperate algal communities worldwide, posing a significant threat to the long-term stability of these iconic ecosystems and the valuable services they provide.
Sydney Harbour: A review of anthropogenic impacts on the biodiversity and ecosystem function of one of the world's largest natural harbours
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/MF15157
Abstract: Sydney Harbour is a hotspot for ersity. However, as with estuaries worldwide, its ersity and functioning faces increasing threats from urbanisation. This is the first synthesis of threats and impacts in Sydney Harbour. In total 200 studies were reviewed: 109 focussed on contamination, 58 on habitat modification, 11 addressed non-indigenous species (NIS) and eight investigated fisheries. Metal concentrations in sediments and seaweeds are among the highest recorded worldwide and organic contamination can also be high. Contamination is associated with increased abundances of opportunistic species, and changes in benthic community structure. The Harbour is also heavily invaded, but invaders’ ecological and economic impacts are poorly quantified. Communities within Sydney Harbour are significantly affected by extensive physical modification, with artificial structures supporting more NIS and lower ersity than their natural equivalents. We know little about the effects of fishing on the Harbour’s ecology, and although ocean warming along Sydney is among the fastest in the world, we know little about how the ecosystem will respond to warming. The interactive and cumulative effects of stressors on ecosystem functioning and services in the Harbour are largely unknown. Sustainable management of this iconic natural system requires that knowledge gaps are addressed and translated into coherent environmental plans.
Intrinsic factors influence the attachment of fragments of the green alga Caulerpa filiformis
Publisher: Elsevier BV
Date: 12-2007
Minimal increase in genetic diversity enhances predation resistance
Publisher: Wiley
Date: 29-12-2011
ABSENCE OF A LARGE BROWN MACROALGA ON URBANIZED ROCKY REEFS AROUND SYDNEY, AUSTRALIA, AND EVIDENCE FOR HISTORICAL DECLINE1
Publisher: Wiley
Date: 30-07-2008
DOI: 10.1111/J.1529-8817.2008.00541.X
Abstract: Loss of habitat-forming algae is increasingly prevalent in temperate marine ecosystems. Here, we document absence of an important habitat-forming macroalga, Phyllospora comosa (Labill.) C. Agardh, along an urbanized coast in New South Wales (NSW), Australia. Dense Phyllospora canopies were common on shallow sublittoral reefs north and south of Sydney. In contrast, we did not find a single in idual along ∼70 km of rocky coastline in the Sydney metropolitan region, despite historical evidence to suggest that it was very common half a century ago. Recolonization of this important habitat-forming alga has not occurred on Sydney reefs despite improved water quality, protection of its habitat, and frequent long-distance dispersal of Phyllospora wrack. While there are obvious limitations, historical information can be useful for identifying potential shifts in community structure to increase our understanding of contemporary ecological patterns.
Toward cross‐realm management of coastal urban ecosystems
Publisher: Wiley
Date: 09-03-2021
DOI: 10.1002/FEE.2323
Broad spectrum effects of secondary metabolites from the red algadelisea pulchrain antifouling assays
Publisher: Informa UK Limited
Date: 05-1995
Patterns of host use among alga- and sponge-associated amphipods
Publisher: Inter-Research Science Center
Date: 2000
DOI: 10.3354/MEPS208183
Climate change and disease: bleaching of a chemically defended seaweed
Publisher: Wiley
Date: 15-06-2011
Using genomics to design and evaluate the performance of underwater forest restoration
Publisher: Wiley
Date: 23-07-2020
Metagenomics Reveals the Influence of Land Use and Rain on the Benthic Microbial Communities in a Tropical Urban Waterway
Publisher: American Society for Microbiology
Date: 26-06-0011
DOI: 10.1128/MSYSTEMS.00136-17
Abstract: Unravelling the microbial metagenomes of urban waterway sediments suggest that well-managed urban waterways have the potential to support erse sedimentary microbial communities, similar to those of undisturbed natural freshwaters. Despite the fact that these urban waterways are well managed, our study shows that environmental pressures from land use and rain perturbations play a role in shaping the structure and functions of microbial communities in these waterways. We propose that although pulsed disturbances, such as rain perturbations, influence microbial communities, press disturbances, including land usage history, have a long-term and stronger influence on microbial communities. Our study found that the functions of microbial communities were less affected by environmental factors than the structure of microbial communities was, indicating that core microbial functions largely remain conserved in challenging environments.
Should we stay or should we go: mechanisms and ecological consequences for biofilm dispersal
Publisher: Springer Science and Business Media LLC
Date: 28-11-2011
DOI: 10.1038/NRMICRO2695
Abstract: In most environments, bacteria reside primarily in biofilms, which are social consortia of cells that are embedded in an extracellular matrix and undergo developmental programmes resulting in a predictable biofilm 'life cycle'. Recent research on many different bacterial species has now shown that the final stage in this life cycle includes the production and release of differentiated dispersal cells. The formation of these cells and their eventual dispersal is initiated through erse and remarkably sophisticated mechanisms, suggesting that there are strong evolutionary pressures for dispersal from an otherwise largely sessile biofilm. The evolutionary aspect of biofilm dispersal is now being explored through the integration of molecular microbiology with eukaryotic ecological and evolutionary theory, which provides a broad conceptual framework for the ersity of specific mechanisms underlying biofilm dispersal. Here, we review recent progress in this emerging field and suggest that the merging of detailed molecular mechanisms with ecological theory will significantly advance our understanding of biofilm biology and ecology.
Ecology of the sea hare Aplysia parvula (Opisthobranchia) in New South Wales, Australia
Publisher: Informa UK Limited
Date: 2003
DOI: 10.1071/MR03004
The seaweed holobiont: understanding seaweed–bacteria interactions
Publisher: Oxford University Press (OUP)
Date: 05-2013
Abstract: Seaweeds (macroalgae) form a erse and ubiquitous group of photosynthetic organisms that play an essential role in aquatic ecosystems. These ecosystem engineers contribute significantly to global primary production and are the major habitat formers on rocky shores in temperate waters, providing food and shelter for aquatic life. Like other eukaryotic organisms, macroalgae harbor a rich ersity of associated microorganisms with functions related to host health and defense. In particular, epiphytic bacterial communities have been reported as essential for normal morphological development of the algal host, and bacteria with antifouling properties are thought to protect chemically undefended macroalgae from detrimental, secondary colonization by other microscopic and macroscopic epibiota. This tight relationship suggests that macroalgae and epiphytic bacteria interact as a unified functional entity or holobiont, analogous to the previously suggested relationship in corals. Moreover, given that the impact of diseases in marine ecosystems is apparently increasing, understanding the role of bacteria as saprophytes and pathogens in seaweed communities may have important implications for marine management strategies. This review reports on the recent advances in the understanding of macroalgal-bacterial interactions with reference to the ersity and functional role of epiphytic bacteria in maintaining algal health, highlighting the holobiont concept.
Contact- and Water-Mediated Effects of Macroalgae on the Physiology and Microbiome of Three Indo-Pacific Coral Species
Publisher: Frontiers Media SA
Date: 22-01-2020
Toward a Coordinated Global Observing System for Seagrasses and Marine Macroalgae
Publisher: Frontiers Media SA
Date: 04-07-2019
Composition, uniqueness and variability of the epiphytic bacterial community of the green alga Ulva australis
Publisher: Springer Science and Business Media LLC
Date: 04-11-2010
Host genetics, phenotype and geography structure the microbiome of a foundational seaweed
Publisher: Wiley
Date: 19-02-2022
DOI: 10.1111/MEC.16378
Abstract: Interactions between hosts and their microbiota are vital to the functioning and resilience of macro‐organisms. Critically, for hosts that play foundational roles in communities, understanding what drives host–microbiota interactions is essential for informing ecosystem restoration and conservation. We investigated the relative influence of host traits and the surrounding environment on microbial communities associated with the foundational seaweed Phyllospora comosa . We quantified 16 morphological and functional phenotypic traits, including host genetics (using 354 single nucleotide polymorphisms) and surface‐associated microbial communities (using 16S rRNA gene licon sequencing) from 160 in iduals s led from eight sites spanning Phyllospora's entire latitudinal distribution (1,300 km). Combined, these factors explained 54% of the overall variation in Phyllospora's associated microbial community structure, much of which was related to the local environment (~32%). We found that putative “core” microbial taxa (i.e., present on all Phyllospora in iduals s led) exhibited slightly higher associations with host traits when compared to “variable” taxa (not present on all in iduals). We identified several key genetic loci and phenotypic traits in Phyllospora that were strongly related to multiple microbial licon sequence variants, including taxa with known associations to seaweed defence, disease and tissue degradation. This information on how host‐associated microbial communities vary with host traits and the environment enhances our current understanding of how “holobionts” (hosts plus their microbiota) are structured. Such understanding can be used to inform management strategies of these important and vulnerable habitats.
Comparisons of diversity of bacterial communities associated with three sessile marine eukaryotes
Publisher: Inter-Research Science Center
Date: 09-08-2007
DOI: 10.3354/AME048217
Demographic consequences of disease in a habitat‐forming seaweed and impacts on interactions between natural enemies
Publisher: Wiley
Date: 2014
DOI: 10.1890/13-0213.1
Abstract: Diseases affecting natural ecosystems are increasing in frequency and severity, but unless obviously catastrophic, the consequences of disease outbreaks are often overlooked, relative to other ecological processes (e.g., predation, competition). Disease can have profound effects on in iduals and can also strongly influence interactions between infected hosts and their natural enemies. We investigated whether a novel bleaching disease affected the survival or performance of a habitat‐forming red seaweed, Delisea pulchra . In addition, we investigated bidirectional, multipartite interactions between this seaweed host, its pathogens, and consumers. Although we found no negative impacts of disease on survival of D. pulchra , bleaching had substantial, negative consequences for affected in iduals, including a dramatic drop in fecundity and a significant decrease in size. In the first direct demonstration of bacterial disease‐mediated herbivory of seaweeds, herbivores generally preferred to consume bleached tissue in feeding trials, and we also found higher densities of herbivores on bleached than co‐occurring, healthy algae at sites where herbivores were abundant. In a conceptually reciprocal test of the effects of herbivores on infection, we showed that simulated herbivory increased susceptibility to bleaching when algae were also exposed to cultures of a bacterial pathogen. Given the high proportions of D. pulchra affected by bleaching during peak periods, the impacts of this disease are likely to have important implications at the population level. This work highlights complex interactions between habitat‐forming organisms and their natural enemies and further emphasizes the need to consider disease in ecological research.
Evidence that halogenated furanones from Delisea pulchra inhibit acylated homoserine lactone (AHL)-mediated gene expression by displacing the AHL signal from its receptor protein
Publisher: Microbiology Society
Date: 02-1999
DOI: 10.1099/13500872-145-2-283
Abstract: Acylated homoserine lactone (AHL)-mediated gene expression controls phenotypes involved in colonization, often specifically of higher organisms, in both marine and terrestrial environments. The marine red alga Delisea pulchra produces halogenated furanones which resemble AHLs structurally and show inhibitory activity at ecologically realistic concentrations in AHL bioassays. Evidence is presented that halogenated furanones displace tritiated OHHL [N-3-(oxohexanoyl)-L-homoserine lactone] from Escherichia coli cells overproducing LuxR with potencies corresponding to their respective inhibitory activities in an AHL-regulated bioluminescence assay, indicating that this is the mechanism by which furanones inhibit AHL-dependent phenotypes. Alternative mechanisms for this phenomenon are also addressed. General metabolic disruption was assessed with two-dimensional PAGE, revealing limited non-AHL-related effects. A direct chemical interaction between the algal compounds and AHLs, as monitored by 1H NMR spectroscopy, was shown not to occur in vitro. These results support the contention that furanones, at the concentrations produced by the alga, can control bacterial colonization of surfaces by specifically interfering with AHL-mediated gene expression at the level of the LuxR protein.
Larval settlement of the common Australian sea urchin Heliocidaris erythrogramma in response to bacteria from the surface of coralline algae
Publisher: Springer Science and Business Media LLC
Date: 23-06-2006
DOI: 10.1007/S00442-006-0470-8
Abstract: Bacterial biofilms are increasingly seen as important for the successful settlement of marine invertebrate larvae. Here we tested the effects of biofilms on settlement of the sea urchin Heliocidaris erythrogramma. Larvae settled on many surfaces including various algal species, rocks, sand and shells. Settlement was reduced by autoclaving rocks and algae, and by treatment of algae with antibiotics. These results, and molecular and culture-based analyses, suggested that the bacterial community on plants was important for settlement. To test this, approximately 250 strains of bacteria were isolated from coralline algae, and larvae were exposed to single-strain biofilms. Many induced rates of settlement comparable to coralline algae. The genus Pseudoalteromonas dominated these highly inductive strains, with representatives from Vibrio, Shewanella, Photobacterium and Pseudomonas also responsible for a high settlement response. The settlement response to different bacteria was species specific, as low inducers were also dominated by species in the genera Pseudoalteromonas and Vibrio. We also, for the first time, assessed settlement of larvae in response to characterised, monospecific biofilms in the field. Larvae metamorphosed in higher numbers on an inducing biofilm, Pseudoalteromonas luteoviolacea, than on either a low-inducing biofilm, Pseudoalteromonas rubra, or an unfilmed control. We conclude that the bacterial community on the surface of coralline algae is important as a settlement cue for H. erythrogramma larvae. This study is also an ex le of the emerging integration of molecular microbiology and more traditional marine eukaryote ecology.
Spatial variation in microbial communities associated with sea-ice algae in Commonwealth Bay, East Antarctica
Publisher: Microbiology Society
Date: 13-04-2022
DOI: 10.1099/MIC.0.001176
Abstract: Antarctic sea-ice forms a complex and dynamic system that drives many ecological processes in the Southern Ocean. Sea-ice microalgae and their associated microbial communities are understood to influence nutrient flow and allocation in marine polar environments. Sea-ice microalgae and their microbiota can have high seasonal and regional ( km 2 ) compositional and abundance variation, driven by factors modulating their growth, symbiotic interactions and function. In contrast, our knowledge of small-scale variation in these communities is limited. Understanding variation across multiple scales and its potential drivers is critical for informing on how multiple stressors impact sea-ice communities and the functions they provide. Here, we characterized bacterial communities associated with sea-ice microalgae and the potential drivers that influence their variation across a range of spatial scales (metres to kms) in a previously understudied area in Commonwealth Bay, East Antarctica where anomalous events have substantially and rapidly expanded local sea-ice coverage. We found a higher abundance and different composition of bacterial communities living in sea-ice microalgae closer to the shore compared to those further from the coast. Variation in community structure increased linearly with distance between s les. Ice thickness and depth to the seabed were found to be poor predictors of these communities. Further research on the small-scale environmental drivers influencing these communities is needed to fully understand how large-scale regional events can affect local function and ecosystem processes.
Coral community response to bleaching on a highly disturbed reef
Publisher: Springer Science and Business Media LLC
Date: 15-02-2016
DOI: 10.1038/SREP20717
Abstract: While many studies of coral bleaching report on broad, regional scale responses, fewer examine variation in susceptibility among coral taxa and changes in community structure, before, during and after bleaching on in idual reefs. Here we report in detail on the response to bleaching by a coral community on a highly disturbed reef site south of mainland Singapore before, during and after a major thermal anomaly in 2010. To estimate the capacity for resistance to thermal stress, we report on: a) overall bleaching severity during and after the event, b) differences in bleaching susceptibility among taxa during the event and c) changes in coral community structure one year before and after bleaching. Approximately two thirds of colonies bleached, however, post-bleaching recovery was quite rapid and, importantly, coral taxa that are usually highly susceptible were relatively unaffected. Although total coral cover declined, there was no significant change in coral taxonomic community structure before and after bleaching. Several factors may have contributed to the overall high resistance of corals at this site including Symbiodinium affiliation, turbidity and heterotrophy. Our results suggest that, despite experiencing chronic anthropogenic disturbances, turbid shallow reef communities may be remarkably resilient to acute thermal stress.
Rücktitelbild: Unidirectional Presentation of Membrane Proteins in Nanoparticle‐Supported Liposomes (Angew. Chem. 29/2019)
Publisher: Wiley
Date: 25-06-2019
Defining marine bacterioplankton community assembly rules by contrasting the importance of environmental determinants and biotic interactions
Publisher: Cold Spring Harbor Laboratory
Date: 04-05-2022
DOI: 10.1101/2022.05.02.490371
Abstract: Bacterioplankton communities play major roles in governing marine productivity and biogeochemical cycling, yet what drives the relative influence of the types of deterministic ecological processes which result in ersity patterns remains unclear. Here we examine how differing deterministic processes (environmental factors and biotic interactions) drive temporal dynamics of bacterioplankton ersity at three different oceanographic time-series locations, spanning 15 degrees of latitude, which are each characterized by different environmental conditions and varying degrees of seasonality. Monthly surface s les, collected over a period of 5.5 years, were analyzed using 16S rRNA licon sequencing. The high and mid-latitude sites of Maria Island and Port Hacking were characterized by high and intermediate levels of environmental heterogeneity respectively, with both alpha (local) ersity (72 % and 24 % of total variation) and beta ersity (32 % and 30 %) patterns within bacterioplankton assemblages primarily explained by environmental determinants, including day length, ammonium, and mixed layer depth. In contrast, at North Stradbroke Island, a sub-tropical location where environmental conditions are less seasonally variable, interspecific interactions were of increased importance in structuring bacterioplankton ersity (alpha ersity: 33 % beta ersity: 26 %) with environment only contributing 11 and 13 % to predicting ersity, respectively. Our results demonstrate that bacterioplankton ersity is the result of both deterministic environmental and biotic processes and that the importance of these different deterministic processes varies, potential in response to environmental heterogeneity. Marine bacterioplankton drives important biological processes, including the cycling of key nutrients or fixing atmospheric carbon. Therefore, to predict future climate scenarios its critical to model these communities accurately. Processes that drive bacterioplankton ersity patterns in the oceans however remain unresolved, with most studies focusing on deterministic environmental drivers, ie temperature or available inorganic nutrients. Biotic deterministic processes including interactions among in iduals are also important for structuring ersity patterns, however, this is rarely included to predict bacterioplankton communities. We develop an approach for determining the relative contribution of environmental and potential biotic interactions that structure marine bacterioplankton at three series at different latitudes. Environmental factors best predicted temporal trends in bacterioplankton ersity at the two high latitude time series, while biotic influence was most apparent at the low latitude time series. Our results suggest environmental heterogeneity is an important attribute driving the contribution of varying deterministic influence of bacterioplankton ersity.
Integrative systems approach reveals dynamics of microbiome-metal-ion axis in mesocosms representing tropical urban freshwater canal ecosystem
Publisher: Cold Spring Harbor Laboratory
Date: 21-09-2020
DOI: 10.1101/2020.09.21.306803
Abstract: Freshwater ecosystems of tr opical u rban c anals s ystems (TrUCS), are highly dynamic and experience constant pressures from interspersed effects of land-use and rain. The dynamic nature of TrUCS ecosystems presents a unique opportunity to unravel the signature interactions between the macro-organisms (top-down), sed imentary mi crobial c ommunities (SedMICs), their functioning and the geochemical environment (bottom-up). A systems level understanding of the molecular and mechanistic basis of the highly dynamic behaviour that leads to specific ecosystem outcomes, is currently lacking. Therefore, a research framework to identify the direct link between top-down and bottom-up ecological effects on SedMICs in a highly dynamic urban canal sedimentary system is needed. Here, we present a framework of integrated multi-dimensional data across system-level biotic and abiotic ecological descriptors, such as environmental variables and active SedMICs. We followed the ecosystem shifts after a natural disturbance (rain) in two different anthropogenic disturbance (land-use) regimes. Shifts in profiles of metabolically active community were conserved across different land-use types, indicating resilience to perturbation is an intrinsic property of the TrUCs ecosystem. Three distinct phases, which were dominated sequentially by autotrophy, anoxic-heterotrophy and oxic-heterotrophy, were identified within these shifts. The first two phases were influenced by the bottom-up effects of specific metal-ion combinations of nitrates and sulfates with magnesium, aluminum and iron, and the third phase was triggered by top-down influences of bioturbation. This generalized systems-level approach, which provides an ecosystem-centric understanding of TrUCS and integrates them in sustainable management practices, can also be extended to other freshwater ecosystems.
Urban blue: A global analysis of the factors shaping people's perceptions of the marine environment and ecological engineering in harbours
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.SCITOTENV.2018.12.285
Abstract: Marine harbours are the focus of a erse range of activities and subject to multiple anthropogenically induced pressures. Support for environmental management options aimed at improving degraded harbours depends on understanding the factors which influence people's perceptions of harbour environments. We used an online survey, across 12 harbours, to assess sources of variation people's perceptions of harbour health and ecological engineering. We tested the hypotheses: 1) people living near impacted harbours would consider their environment to be more unhealthy and degraded, be more concerned about the environment and supportive of and willing to pay for ecological engineering relative to those living by less impacted harbours, and 2) people with greater connectedness to the harbour would be more concerned about and have greater perceived knowledge of the environment, and be more supportive of, knowledgeable about and willing to pay for ecological engineering, than those with less connectedness. Across twelve locations, the levels of degradation and modification by artificial structures were lower and the concern and knowledge about the environment and ecological engineering were greater in the six Australasian and American than the six European and Asian harbours surveyed. We found that people's perception of harbours as healthy or degraded, but not their concern for the environment, reflected the degree to which harbours were impacted. There was a positive relationship between the percentage of shoreline modified and the extent of support for and people's willingness to pay indirect costs for ecological engineering. At the in idual level, measures of connectedness to the harbour environment were good predictors of concern for and perceived knowledge about the environment but not support for and perceived knowledge about ecological engineering. To make informed decisions, it is important that people are empowered with sufficient knowledge of the environmental issues facing their harbour and ecological engineering options.
Cost of chemical defence in the red alga Delisea pulchra
Publisher: Wiley
Date: 17-02-2006
Social–environmental drivers inform strategic management of coral reefs in the Anthropocene
Publisher: Springer Science and Business Media LLC
Date: 12-08-2019
DOI: 10.1038/S41559-019-0953-8
Abstract: Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages-the foundation species of coral reef ecosystems. Here, we compiled coral abundance data from 2,584 Indo-Pacific reefs to evaluate the influence of 21 climate, social and environmental drivers on the ecology of reef coral assemblages. Higher abundances of framework-building corals were typically associated with: weaker thermal disturbances and longer intervals for potential recovery slower human population growth reduced access by human settlements and markets and less nearby agriculture. We therefore propose a framework of three management strategies (protect, recover or transform) by considering: (1) if reefs were above or below a proposed threshold of >10% cover of the coral taxa important for structural complexity and carbonate production and (2) reef exposure to severe thermal stress during the 2014-2017 global coral bleaching event. Our findings can guide urgent management efforts for coral reefs, by identifying key threats across multiple scales and strategic policy priorities that might sustain a network of functioning reefs in the Indo-Pacific to avoid ecosystem collapse.
Increasing microhabitat complexity on seawalls can reduce fish predation on native oysters
Publisher: Elsevier BV
Date: 09-2018
13C NMR study ofN-acyl-S-homoserine lactone derivatives
Publisher: Wiley
Date: 02-1999
DOI: 10.1002/(SICI)1097-458X(199902)37:2<157::AID-MRC329>3.0.CO;2-7
Interactions within the microbiome alter microbial interactions with host chemical defences and affect disease in a marine holobiont
Publisher: Springer Science and Business Media LLC
Date: 04-02-2019
DOI: 10.1038/S41598-018-37062-Z
Abstract: Our understanding of diseases has been transformed by the realisation that people are holobionts, comprised of a host and its associated microbiome(s). Disease can also have devastating effects on populations of marine organisms, including dominant habitat formers such as seaweed holobionts. However, we know very little about how interactions between microorganisms within microbiomes - of humans or marine organisms – affect host health and there is no underpinning theoretical framework for exploring this. We applied ecological models of succession to bacterial communities to understand how interactions within a seaweed microbiome affect the host. We observed succession of surface microbiomes on the red seaweed Delisea pulchra in situ , following a disturbance, with communities ‘recovering’ to resemble undisturbed states after only 12 days. Further, if this recovery was perturbed, a bleaching disease previously described for this seaweed developed. Early successional strains of bacteria protected the host from colonisation by a pathogenic, later successional strain. Host chemical defences also prevented disease, such that within-microbiome interactions were most important when the host’s chemical defences were inhibited. This is the first experimental evidence that interactions within microbiomes have important implications for host health and disease in a dominant marine habitat-forming organism.
A horizon scan of priorities for coastal marine microbiome research
Publisher: Springer Science and Business Media LLC
Date: 21-10-2014
DOI: 10.1038/S41559-019-0999-7
Abstract: 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 ex le, 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'. Understanding of coastal ecosystem function must therefore be framed under the holobiont concept, whereby macroorganisms and their associated microbiomes are considered as a synergistic ecological unit. Here, we evaluate the current state of knowledge on coastal marine microbiome research and identify key questions within this growing research area. Although the list of questions is broad and ambitious, progress in the field is increasing exponentially, and the emergence of large, international collaborative networks and well-executed manipulative experiments are rapidly advancing the field of coastal marine microbiome research.
Building blue infrastructure: Assessing the key environmental issues and priority areas for ecological engineering initiatives in Australia's metropolitan embayments
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.JENVMAN.2018.09.047
Abstract: Ecological engineering principles are increasingly being applied to develop multifunctional artificial structures or rehabilitated habitats in coastal areas. Ecological engineering initiatives are primarily driven by marine scientists and coastal managers, but often the views of key user groups, which can strongly influence the success of projects, are not considered. We used an online survey and participatory mapping exercise to investigate differences in priority goals, sites and attitudes towards ecological engineering between marine scientists and coastal managers as compared to other stakeholders. The surveys were conducted across three Australian cities that varied in their level of urbanisation and environmental pressures. We tested the hypotheses that, relative to other stakeholders, marine scientists and coastal managers will: 1) be more supportive of ecological engineering 2) be more likely to agree that enhancement of bio ersity and remediation of pollution are key priorities for ecological engineering and 3) identify different priority areas and infrastructure or degraded habitats for ecological engineering. We also tested the hypothesis that 4) perceptions of ecological engineering would vary among locations, due to environmental and socio-economic differences. In all three harbours, marine scientists and coastal managers were more supportive of ecological engineering than other users. There was also greater support for ecological engineering in Sydney and Melbourne than Hobart. Most people identified transport infrastructure, in busy transport hubs (i.e. Circular Quay in Sydney, the Port in Melbourne and the Waterfront in Hobart) as priorities for ecological engineering, irrespective of their stakeholder group or location. There were, however, significant differences among locations in what people perceive as the key priorities for ecological engineering (i.e. bio ersity in Sydney and Melbourne vs. pollution in Hobart). Greater consideration of these location-specific differences is essential for effective management of artificial structures and rehabilitated habitats in urban embayments.
Sydney Harbour: Beautiful, diverse, valuable and pressured
Publisher: Elsevier BV
Date: 11-2016
Microtopography and antifouling properties of the shell surface of the bivalve molluscs mytilus galloprovincialis and pinctada imbricata
Publisher: Informa UK Limited
Date: 2003
DOI: 10.1080/0892701021000057882
Abstract: Biofouling rapidly covers most submerged surfaces in the marine environment. However, some marine organisms remain clean despite strong fouling pressure. Potential physical inhibitors of fouling were investigated by comparing the thickness, cover, and microtopographic structure of the periostracum of two bivalve molluscs, the blue mussel, Mytilus galloprovincialis, and the pearl oyster, Pinctada imbricata. The cover and thickness of the periostracum were measured on four size classes of each species using histological and microscopic techniques. The periostracum of M. galloprovincialis was significantly thicker than that of P. imbricata and did not differ significantly between size classes. In contrast, the periostracum of P. imbricata decreased significantly with increasing size in both thickness and cover. The microtopography of the shell surface of both species was measured using atomic force microscopy (AFM) and scanning electron microscopy (SEM), which revealed a homogeneous ridged surface for M. galloprovincialis with a uniform distance of 1-2 microns between ridges with a mean depth of 1.5 microns. P. imbricata had a heterogeneous surface structure without a repeating structural pattern. To compare the potential antifouling properties of the shell surface the four size classes of both species were tested in fourteen-week field exposure trials. M. galloprovincialis was rarely fouled over the trial period with less than 10% of M. galloprovincialis shell across all size classes being fouled. In contrast, P. imbricata had significantly higher levels of fouling. Both the proportion of P. imbricata shells fouled and the density of fouling organisms were positively correlated with the age of the shell and the amount of intact periostracum. The relationship between the shell surface microtopography and the intensity of fouling is discussed.
Chemical cues for surface colonization.
Publisher: Springer Science and Business Media LLC
Date: 2002
Abstract: Colonization of surfaces in marine benthic environments is often one of the most significant moments in the life history of benthic organisms, representing, for ex le, a change from a planktonic to a benthic existence, a shift from a mobile to a sessile life form, or the initiation of pathogenesis. Many of the surfaces that are colonized are, in fact, other marine organisms, and in a general sense there is widespread evidence that specific chemical cues derived from marine organisms affect colonization by both marine prokaryotes and eukaryotes. However, detailed information for any one system on the nature of such cues, their distribution in situ, and their effects on the demography of colonizers is rare. Here, we selectively review the literature on chemical cues for colonization in the sea, focussing on contrasts between positive (inducers) and negative (inhibitors, deterrents) cues and on prokaryote/eukaryote interactions. We also consider whether generalized life history or natural history characteristics of colonizers (i.e., the mobility of a propagule, the extent to which a species is a habitat generalist or specialist, etc.) affect their response to chemical cues, and we touch briefly on some recent highlights relevant to the critical interplay between hydrodynamics and chemistry. A number of important methodological concerns are now being addressed through the introduction of field assays and analyses for chemical cues, and through molecular techniques for the characterization of microbial biofilms. These developments are encouraging, as is the increasingly multidisciplinary and cross-taxonomic approach to research in this area.
Chemical defenses of seaweeds against microbial colonization
Publisher: Springer Science and Business Media LLC
Date: 1997
Natural densities of mesograzers fail to limit growth of macroalgae or their epiphytes in a temperate algal bed
Publisher: Wiley
Date: 11-12-2008
Emerging Solutions to Return Nature to the Urban Ocean
Publisher: Annual Reviews
Date: 03-01-2021
DOI: 10.1146/ANNUREV-MARINE-032020-020015
Abstract: Urban and periurban ocean developments impact 1.5% of the global exclusive economic zones, and the demand for ocean space and resources is increasing. As we strive for a more sustainable future, it is imperative that we better design, manage, and conserve urban ocean spaces for both humans and nature. We identify three key objectives for more sustainable urban oceans: reduction of urban pressures, protection and restoration of ocean ecosystems, and support of critical ecosystem services. We describe an array of emerging evidence-based approaches, including greening grayinfrastructure, restoring habitats, and developing biotechnologies. We then explore new economic instruments and incentives for supporting these new approaches and evaluate their feasibility in delivering these objectives. Several of these tools have the potential to help bring nature back to the urban ocean while also addressing some of the critical needs of urban societies, such as climate adaptation, seafood production, clean water, and recreation, providing both human and environmental benefits in some of our most impacted ocean spaces.
Impact of marine protected areas on temporal stability of fish species diversity
Publisher: Wiley
Date: 29-09-2021
DOI: 10.1111/COBI.13815
Abstract: Preserving bio ersity over time is a pressing challenge for conservation science. A key goal of marine protected areas (MPAs) is to maintain stability in species composition, via reduced turnover, to support ecosystem function. Yet, this stability is rarely measured directly under different levels of protection. Rather, evaluations of MPA efficacy generally consist of static measures of abundance, species richness, and biomass, and rare measures of turnover are limited to short‐term studies involving pairwise (beta ersity) comparisons. Zeta ersity is a recently developed metric of turnover that allows for measurement of compositional similarity across multiple assemblages and thus provides more comprehensive estimates of turnover. We evaluated the effectiveness of MPAs at preserving fish zeta ersity across a network of marine reserves over 10 years in Batemans Marine Park, Australia. Snorkel transect surveys were conducted across multiple replicated and spatially interspersed sites to record fish species occurrence through time. Protection provided by MPAs conferred greater stability in fish species turnover. Marine protected areas had significantly shallower decline in zeta ersity compared with partially protected and unprotected areas. The retention of harvested species was four to six times greater in MPAs compared with partially protected and unprotected areas, and the stabilizing effects of protection were observable within 4 years of park implementation. Conversely, partial protection offered little to no improvement in stability, compared with unprotected areas. These findings support the efficacy of MPAs for preserving temporal fish ersity stability. The implementation of MPAs helps stabilize fish ersity and may, therefore, support bio ersity resilience under ongoing environmental change.
Interacting effects of habitat structure and seeding with oysters on the intertidal biodiversity of seawalls
Publisher: Public Library of Science (PLoS)
Date: 16-07-2020
Chemical mediation of bacterial surface colonisation by secondary metabolites from the red alga Delisea pulchra
Publisher: Inter-Research Science Center
Date: 1998
DOI: 10.3354/AME015233
Induction of metamorphosis in the sea urchin Holopneustes purpurascens by a metabolite complex from the algal host Delisea pulchra
Publisher: University of Chicago Press
Date: 06-2000
DOI: 10.2307/1542689
Abstract: Most benthic invertebrates have complex life cycles with planktonic larvae that return to the substratum to settle and metamorphose into a benthic stage. Although naturally produced chemical cues have long been thought to be important for the settlement or metamorphosis of invertebrate larvae, few ecologically relevant chemical cues have been clearly identified. The marine echinoid Holopneustes purpurascens has a complex life cycle, with a planktonic, nonfeeding dispersive larva that metamorphoses into a benthic stage that lives in the canopy of subtidal benthic algae such as the red alga Delisea pulchra and the kelp Ecklonia radiata. Recently recruited juveniles are found primarily on D. pulchra, and we hypothesized that this was in response to a chemical cue produced by this alga. Competent larvae metamorphosed in the presence of D. pulchra, or seawater surrounding this alga, but not in response to the presence of E. radiata or its extracts. A cue for metamorphosis was isolated and characterized from D. pulchra and found to be a water-soluble complex of the sugar floridoside and isethionic acid in a 1:1 molar ratio. The floridoside-isethionic acid complex also triggered settlement in H. purpurascens however, this response was less specific than metamorphosis and was reversible. Larvae of H. purpurascens also metamorphosed in the presence of several other species of red, but not brown or green, algae from their habitat. Floridoside is found only in red algae, suggesting that the floridoside-isethionic acid complex may be acting as a cue for metamorphosis in other red algae as well as in D. pulchra.
Settlement of larval blacklip abalone, Haliotis rubra, in response to green and red macroalgae
Publisher: Springer Science and Business Media LLC
Date: 18-06-2005
Kinetics of the AHL Regulatory System in a Model Biofilm System: How Many Bacteria Constitute a “Quorum”?
Publisher: Elsevier BV
Date: 06-2008
Does restoration of a habitat‐forming seaweed restore associated faunal diversity?
Publisher: Wiley
Date: 26-10-2015
DOI: 10.1111/REC.12292
Coral Settlement on a Highly Disturbed Equatorial Reef System
Publisher: Public Library of Science (PLoS)
Date: 20-05-2015
Measuring continuous compositional change using decline and decay in zeta diversity
Publisher: Wiley
Date: 14-08-2019
DOI: 10.1002/ECY.2832
Abstract: Incidence, or compositional, matrices are generated for a broad range of research applications in biology. Zeta ersity provides a common currency and conceptual framework that links incidence-based metrics with multiple patterns of interest in biology, ecology, and bio ersity science. It quantifies the variation in species (or OTU) composition of multiple assemblages (or cases) in space or time, to capture the contribution of the full suite of narrow, intermediate, and wide-ranging species to biotic heterogeneity. Here we provide a conceptual framework for the application and interpretation of patterns of continuous change in compositional ersity using zeta ersity. This includes consideration of the survey design context, and the multiple ways in which zeta ersity decline and decay can be used to examine and test turnover in the identity of elements across space and time. We introduce the zeta ratio-based retention rate curve to quantify rates of compositional change. We illustrate these applications using 11 empirical data sets from a broad range of taxa, scales, and levels of biological organization-from DNA molecules and microbes to communities and interaction networks-including one of the original data sets used to express compositional change and distance decay in ecology. We show (1) how different s le selection schemes used during the calculation of compositional change are appropriate for different data types and questions, (2) how higher orders of zeta may in some cases better detect shifts and transitions, and (3) the relative roles of rare vs. common species in driving patterns of compositional change. By exploring the application of zeta ersity decline and decay, including the retention rate, across this broad range of contexts, we demonstrate its application for understanding continuous turnover in biological systems.
Tropicalization and kelp loss shift trophic composition and lead to more winners than losers in fish communities
Publisher: Wiley
Date: 30-03-2021
DOI: 10.1111/GCB.15592
Abstract: Climate‐mediated species redistributions are causing novel interactions and leading to profound regime shifts globally. For species that expand their distribution in response to warming, survival depends not only on their physiological capacity, but also on the ability to coexist or be competitive within the established community. In temperate marine reefs from around the world, the range expansion of tropical species, known as ‘tropicalization’, has been linked to the disappearance of temperate habitat‐forming kelps and shifts to dominance by low‐biomass turfing algae. The consequences of these range expansions and habitat changes on resident fish communities are, however, unclear. Here, we use data derived from baited remote underwater video (BRUV) surveys to analyse changes in ersity and abundance of marine fishes over a 17‐year period in warming reefs that have experienced kelp loss (occurring c. 2009). Despite the loss of kelp, we found that species richness and overall abundance of fishes (measured as probability of occurrence and relative abundance), including both tropical and temperate species, increased through time. We also found dramatic shifts in the trophic composition of fish assemblages. Tropical herbivorous fish increased most markedly through time, and temperate‐associated planktivores were the only group that declined, a potential consequence of tropicalization not previously identified. At the species level, we identified 22 tropical and temperate species from four trophic guilds that significantly increased in occurrence, while only three species (all temperate associated) declined. Morphological trait space models suggest increases in fish ersity and overall occurrence are unlikely to be driven by uniqueness of traits among tropical range expanders. Our results show more winners than losers and suggest that pathways of energy flow will change in tropicalized systems, as planktonic inputs become less important and a higher proportion of algal productivity gets consumed locally by increasingly abundant herbivores.
Factors associated with oligophagy in two species of sea hares (Mollusca: Anaspidea)
Publisher: Elsevier BV
Date: 10-1995
Biogeography of bacteria associated with the marine sponge Cymbastela concentrica
Publisher: Wiley
Date: 10-01-2005
DOI: 10.1111/J.1462-2920.2004.00711.X
Abstract: Recent debate regarding microbial biogeography has focused largely on free-living microbes, yet those microbes associated with host organisms are also of interest from a biogeographical perspective. Marine eukaryotes and associated bacteria should provide ideal systems in which to consider microbial biogeography, as (i) bacteria in seawater should be able to disperse among in iduals of the same host species, yet (ii) potential for adaptation to particular hosts (and thus speciation) also exists. We used 16S rDNA-DGGE (denaturing gradient gel electrophoresis) to examine geographic variability in bacterial community composition in the marine sponge Cymbastela concentrica. Denaturing gradient gel electrophoresis banding patterns (and phylogenetic analysis of excised DGGE bands) indicated different communities in Cymbastela concentrica from tropical versus temperate Australia. In contrast, communities were very similar over a 500-km portion of the sponge's temperate range. Variation in bacterial community composition was also considered with respect to ocean current patterns. We speculate that the ergent communities in different parts of the sponge's range provide evidence of endemism attributed to host association, although variation in environmental factors such as light and temperature could also explain the observed results. Interestingly, bacterial communities in seawater varied much less between tropical and temperate locations than did those in C. concentrica, supporting the concept of widespread dispersal among these free-living microbes.
The Effects of Foul-release Coatings on the Settlement and Behaviour of Cyprid Larvae of the Barnacle Balanus amphitrite amphitrite Darwin
Publisher: Informa UK Limited
Date: 2003
DOI: 10.1080/0892701021000057909
Abstract: Foul-release coatings are generally assumed to affect fouling of surfaces via interfering with adhesion of fouling organisms. However, the potential effects of these coatings on other aspects of the biology of fouling organisms such as behaviour have not in general been explored. The effects of wax-based foul-release coatings containing silicone oil on the settlement and behaviour of cyprid larvae of the barnacle Balanus hitrite were studied. Settlement (as measured by metamorphosis) of cyprids was strongly inhibited on all coatings but particularly on those containing silicone oil at concentrations of 5% or more. The behaviour of cyprids was also altered on coatings containing > or = 5% silicone oil, with cyprids assuming an inverted position, preventing adhesion. This effect was reversible in part when cyprids exposed to experimental coatings for 1 d were transferred to uncoated surfaces their behaviour returned to normal, except that metamorphosis did not occur. The results indicate that model foul-release coatings containing wax and silicone oil can affect settlement and behaviour, as well as adhesion.
Future climate change is predicted to affect the microbiome and condition of habitat-forming kelp
Publisher: The Royal Society
Date: 06-02-2019
Abstract: Climate change is driving global declines of marine habitat-forming species through physiological effects and through changes to ecological interactions, with projected trajectories for ocean warming and acidification likely to exacerbate such impacts in coming decades. Interactions between habitat-formers and their microbiomes are fundamental for host functioning and resilience, but how such relationships will change in future conditions is largely unknown. We investigated independent and interactive effects of warming and acidification on a large brown seaweed, the kelp Ecklonia radiata , and its associated microbiome in experimental mesocosms. Microbial communities were affected by warming and, during the first week, by acidification. During the second week, kelp developed disease-like symptoms previously observed in the field. The tissue of some kelp blistered, bleached and eventually degraded, particularly under the acidification treatments, affecting photosynthetic efficiency. Microbial communities differed between blistered and healthy kelp for all treatments, except for those under future conditions of warming and acidification, which after two weeks resembled assemblages associated with healthy hosts. This indicates that changes in the microbiome were not easily predictable as the severity of future climate scenarios increased. Future ocean conditions can change kelp microbiomes and may lead to host disease, with potentially cascading impacts on associated ecosystems.
Eukaryotic interference with homoserine lactone-mediated prokaryotic signalling
Publisher: American Society for Microbiology
Date: 11-1996
DOI: 10.1128/JB.178.22.6618-6622.1996
Abstract: Acylated homoserine lactones (AHLs) play a widespread role in intercellular communication among bacteria. The Australian macroalga Delisea pulchra produces secondary metabolites which have structural similarities to AHL molecules. We report here that these metabolites inhibited AHL-controlled processes in prokaryotes. Our results suggest that the interaction between higher organisms and their surface-associated bacteria may be mediated by interference with bacterial regulatory systems.
Expanding the Symbiodinium (Dinophyceae, Suessiales) Toolkit Through Protoplast Technology
Publisher: Wiley
Date: 21-02-2017
DOI: 10.1111/JEU.12393
Abstract: Dinoflagellates within the genus Symbiodinium are photosymbionts of many tropical reef invertebrates, including corals, making them central to the health of coral reefs. Symbiodinium have therefore gained significant research attention, though studies have been constrained by technical limitations. In particular, the generation of viable cells with their cell walls removed (termed protoplasts) has enabled a wide range of experimental techniques for bacteria, fungi, plants, and algae such as ultrastructure studies, virus infection studies, patch cl ing, genetic transformation, and protoplast fusion. However, previous studies have struggled to remove the cell walls from armored dinoflagellates, potentially due to the internal placement of their cell walls. Here, we produce the first Symbiodinium protoplasts from three genetically and physiologically distinct strains via incubation with cellulase and osmotic agents. Digestion of the cell walls was verified by a lack of Calcofluor White fluorescence signal and by cell swelling in hypotonic culture medium. Fused protoplasts were also observed, motivating future investigation into intra- and inter-specific somatic hybridization of Symbiodinium. Following digestion and transfer to regeneration medium, protoplasts remained photosynthetically active, regrew cell walls, regained motility, and entered exponential growth. Generation of Symbiodinium protoplasts opens exciting, new avenues for researching these crucial symbiotic dinoflagellates, including genetic modification.
Global kelp forest restoration: past lessons, present status, and future directions
Publisher: Wiley
Date: 07-03-2022
DOI: 10.1111/BRV.12850
Abstract: Kelp forest ecosystems and their associated ecosystem services are declining around the world. In response, marine managers are working to restore and counteract these declines. Kelp restoration first started in the 1700s in Japan and since then has spread across the globe. Restoration efforts, however, have been largely disconnected, with varying methodologies trialled by different actors in different countries. Moreover, a small subset of these efforts are ‘afforestation’, which focuses on creating new kelp habitat, as opposed to restoring kelp where it previously existed. To distil lessons learned over the last 300 years of kelp restoration, we review the history of kelp restoration (including afforestation) around the world and synthesise the results of 259 documented restoration attempts spanning from 1957 to 2020, across 16 countries, five languages, and multiple user groups. Our results show that kelp restoration projects have increased in frequency, have employed 10 different methodologies and targeted 17 different kelp genera. Of these projects, the majority have been led by academics (62%), have been conducted at sizes of less than 1 ha (80%) and took place over time spans of less than 2 years. We show that projects are most successful when they are located near existing kelp forests. Further, disturbance events such as sea‐urchin grazing are identified as regular causes of project failure. Costs for restoration are historically high, averaging hundreds of thousands of dollars per hectare, therefore we explore avenues to reduce these costs and suggest financial and legal pathways for scaling up future restoration efforts. One key suggestion is the creation of a living database which serves as a platform for recording restoration projects, showcasing and/or re‐analysing existing data, and providing updated information. Our work establishes the groundwork to provide adaptive and relevant recommendations on best practices for kelp restoration projects today and into the future.
A weight-of-evidence approach for identifying potential sources of untreated sewage inputs into a complex urbanized catchment
Publisher: Elsevier BV
Date: 04-2021
Corals Like It Waxed: Paraffin-Based Antifouling Technology Enhances Coral Spat Survival
Publisher: Public Library of Science (PLoS)
Date: 28-01-2014
Impacts of climate change in a global hotspot for temperate marine biodiversity and ocean warming
Publisher: Elsevier BV
Date: 04-2011
Density-dependent sea urchin grazing: differential removal of species, changes in community composition and alternative community states
Publisher: Inter-Research Science Center
Date: 2005
DOI: 10.3354/MEPS298143
Lack of avoidance of phenolic-rich brown algae by tropical herbivorous fishes
Publisher: Springer Science and Business Media LLC
Date: 06-1991
DOI: 10.1007/BF01319401
Conflicts in some of the World harbours: what needs to happen next?
Publisher: Springer Science and Business Media LLC
Date: 19-08-2016
A communal catalogue reveals Earth’s multiscale microbial diversity
Publisher: Springer Science and Business Media LLC
Date: 11-2017
DOI: 10.1038/NATURE24621
Abstract: Our growing awareness of the microbial world’s importance and ersity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community s les collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of ersity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial ersity.
Restoring subtidal marine macrophytes in the Anthropocene: trajectories and future-proofing
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/MF18226
Abstract: Anthropogenic activities have caused profound changes globally in bio ersity, species interactions and ecosystem functions and services. In terrestrial systems, restoration has emerged as a useful approach to mitigate these changes, and is increasingly recognised as a tool to fortify ecosystems against future disturbances. In marine systems, restoration is also gaining traction as a management tool, but it is still comparatively scant and underdeveloped relative to terrestrial environments. Key coastal habitats, such as seaweed forests and seagrass meadows are showing widespread patterns of decline around the world. As these important ecosystems increasingly become the target of emerging marine restoration c aigns, it is important not only to address current environmental degradation issues, but also to focus on the future. Given the rate at which marine and other environments are changing, and given predicted increases in the frequency and magnitude of multiple stressors, we argue for an urgent need for subtidal marine macrophyte restoration efforts that explicitly incorporate future-proofing in their goals. Here we highlight emerging scientific techniques that can help achieve this, and discuss changes to managerial, political and public frameworks that are needed to support scientific innovation and restoration applications at scale.
Large-scale assessment of benthic communities across multiple marine protected areas using an autonomous underwater vehicle
Publisher: Public Library of Science (PLoS)
Date: 16-03-2018
Bringing harbours alive: assessing the importance of eco-engineered coastal infrastructure for different stakeholders and cities
Publisher: Elsevier BV
Date: 08-2018
Larval settlement preference of a native bivalve: the influence of an invasive alga versus native substrata
Publisher: Inter-Research Science Center
Date: 05-11-2009
DOI: 10.3354/AB00196
Operation Crayweed: Ecological and sociocultural aspects of restoring Sydney’s underwater forests
Publisher: Wiley
Date: 05-2020
DOI: 10.1111/EMR.12413
Interspecific diversity reduces and functionally substitutes for intraspecific variation in biofilm communities
Publisher: Springer Science and Business Media LLC
Date: 25-09-2015
Playing to the Positives: Using Synergies to Enhance Kelp Forest Restoration
Publisher: Frontiers Media SA
Date: 10-07-2020
The effects of warming and ocean acidification on growth, photosynthesis, and bacterial communities for the marine invasive macroalga Caulerpa taxifolia
Publisher: Wiley
Date: 11-2017
DOI: 10.1002/LNO.10739
27 years of benthic and coral community dynamics on turbid, highly urbanised reefs off Singapore
Publisher: Springer Science and Business Media LLC
Date: 08-11-2016
DOI: 10.1038/SREP36260
Abstract: Coral cover on reefs is declining globally due to coastal development, overfishing and climate change. Reefs isolated from direct human influence can recover from natural acute disturbances, but little is known about long term recovery of reefs experiencing chronic human disturbances. Here we investigate responses to acute bleaching disturbances on turbid reefs off Singapore, at two depths over a period of 27 years. Coral cover declined and there were marked changes in coral and benthic community structure during the first decade of monitoring at both depths. At shallower reef crest sites (3–4 m), benthic community structure recovered towards pre-disturbance states within a decade. In contrast, there was a net decline in coral cover and continuing shifts in community structure at deeper reef slope sites (6–7 m). There was no evidence of phase shifts to macroalgal dominance but coral habitats at deeper sites were replaced by unstable substrata such as fine sediments and rubble. The persistence of coral dominance at chronically disturbed shallow sites is likely due to an abundance of coral taxa which are tolerant to environmental stress. In addition, high turbidity may interact antagonistically with other disturbances to reduce the impact of thermal stress and limit macroalgal growth rates.
Sea urchin larvae decipher the epiphytic bacterial community composition when selecting sites for attachment and metamorphosis
Publisher: Oxford University Press (OUP)
Date: 05-12-2014
Abstract: Most marine invertebrates have dispersive larvae and relatively immobile adults. These developmental stages are linked by a settlement event, which is often mediated by specific cues in bacterial biofilms. While larvae distinguish between biofilms from different environments, it remains unknown if they receive information from all, only a few or even just a single bacterial species in natural biofilms. Here we asked how specific is larval settlement to the bacterial community structure and/or taxonomically distinguishable groups of bacteria in epiphytic marine biofilms? We used novel multivariate statistical approaches to investigate if larval settlement of two sea urchins correlated with the microbial community composition. Larval settlement of Heliocidaris erythrogramma revealed a strong correlation with the community composition, highlighted by canonical analysis of principle components, a constrained ordination technique. Using this technique, the importance of operational taxonomic units (OTUs) within communities relative to larval settlement was investigated. Larval settlement not only correlated, both positively and negatively, with the epiphytic bacterial community composition but also with the relative abundance of few OTUs within these communities. In contrast, no such correlation was observed for the other urchin, Holopneustes purpurascens, whose larvae likely respond to bacterial biofilms in a more general way and specifically respond to a defined settlement cue of algal origin.
Induction of Settlement of Larvae of the Sea UrchinHolopneustes purpurascensby Histamine From a Host Alga
Publisher: University of Chicago Press
Date: 06-2004
DOI: 10.2307/1543640
Abstract: Larvae of the Australian sea urchin Holopneustes purpurascens are induced to settle and metamorphose (termed settlement herein) by a water-soluble compound produced by the red alga Delisea pulchra, the main host plant of new recruits. The settlement cue for H. purpurascens had previously been identified as a floridoside-isethionic acid complex, and this paper presents new evidence correcting that finding. The actual settlement cue produced by D. pulchra was isolated from the polar extract by cation-exchange chromatography and identified as histamine, using one- and two-dimensional nuclear magnetic resonance spectrometry. The chemical identity of the cue was confirmed by gas chromatography-mass spectrometry (GC-MS) and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. Synthetic histamine and histamine at 4.5 microM isolated from D. pulchra both induced rapid settlement in 80%-100% of the larvae of H. purpurascens. Lower concentrations of histamine (0.9-2.3 micro M) induced larval settlement, but this response varied from 0%-90%. The histamine content of two host plants of H. purpurascens--D. pulchra and Ecklonia radiata--and of four other common species was quantified using GC-MS. D. pulchra had the highest histamine content, which is consistent with H. purpurascens recruiting to this species. Histamine was also detected in the seawater surrounding these host algae. This is the first time that a settlement cue has been quantified in the habitat of a marine organism.
Restoring seaweeds: does the declining fucoid Phyllospora comosa support different biodiversity than other habitats?
Publisher: Springer Science and Business Media LLC
Date: 12-10-2013
Fimbrolide-coated antimicrobial lenses: Their in vitro and in vivo effects
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2008
Molecular analysis of a fungal disease in the habitat‐forming brown macroalga Phyllospora comosa (Fucales) along a latitudinal gradient
Publisher: Wiley
Date: 26-05-2021
DOI: 10.1111/JPY.13180
Abstract: Infectious diseases affecting habitat‐forming species can have significant impacts on population dynamics and alter the structure and functioning of marine ecosystems. Recently, a fungal infection was described as the causative agent of necrotic lesions on the stipe of the forest‐forming macroalga Phyllospora comosa , a disease named “stipe rot” (SR). Here, we developed a quantitative PCR (qPCR) method for rapid detection and quantification of this pathogen, which was applied to evaluate the level of SR infection in eight P . comosa populations spanning the entire latitudinal distribution of this species along southeastern Australia. We also investigated the relationship between the abundance and prevalence of Stipe Rot Fungus (SRF) and potential host chemical defenses as well as its relationship with morphological and ecophysiological traits of P . comosa . qPCR estimates of SRF abundance reflected the levels of infection estimated by visual assessment, with higher numbers of SRF copies being observed in in iduals showing high or intermediate levels of visual symptoms of SR. Concordance of conventional PCR and visual assessments was 92 and 94%, respectively, compared to qPCR detection. SRF prevalence was positively related to fucoxanthin content and herbivory, but not significant related to other traits measured (phlorotannin content, total length, thallus diameter, stipe width, number of branches, frond width, fouling, bleaching, gender, and photosynthetic efficiency). These results provide confidence for previous reports of this disease based upon visual assessments only, contribute to the development of monitoring and conservation strategies for safeguarding P . comosa forests, and generate insights into potential factors influencing host–pathogen interactions in this system.
The surface bacterial community of an Australian kelp shows cross-continental variation and relative stability within regions
Publisher: Oxford University Press (OUP)
Date: 22-06-2021
Abstract: 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 in idual 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. Here, s les were taken from the ecologically important kelp, Ecklonia radiata, over a 17-month period, from six different sites in two distinct geographic regions (East and West coasts of Australia), separated by ∼3,300 kms, to understand variation in the kelp bacterial community and its potential environmental drivers. Differences were observed between kelp bacterial communities between the largely disconnected geographical regions. In contrast, within each region and over time the bacterial communities were considerably more stable, despite substantial seasonal changes in environmental conditions.
Tropicalisation of temperate reefs: Implications for ecosystem functions and management actions
Publisher: Wiley
Date: 11-03-2019
Host specificity in marine sponge‐associated bacteria, and potential implications for marine microbial diversity
Publisher: Wiley
Date: 19-12-2003
DOI: 10.1046/J.1462-2920.2003.00545.X
Abstract: Bio ersity is fundamental to both eukaryote and prokaryote ecology, yet investigations of ersity often differ markedly between the two disciplines. Host specificity - the association of organisms with only a few (specialism) or many (generalism) host species - is recognized within eukaryote ecology as a key determinant of ersity. In contrast, its implications for microbial ersity have received relatively little attention. Here we explore the relationship between microbial ersity and host specificity using marine sponge-bacteria associations. We used a replicated, hierarchical s ling design and both 16S rDNA- and rpoB-based denaturing gradient gel electrophoresis (DGGE) to examine whether three co-occurring sponges from temperate Australia -Cymbastela concentrica, Callyspongia sp. and Stylinos sp. - contained unique, specialized communities of microbes. Microbial communities varied little within each species of sponge, but variability among species was substantial. Over five seasons, the microbial community in C. concentrica differed significantly from other sponges, which were more similar to seawater. Overall, three types of sponge-associated bacteria were identified via 16S rDNA sequencing of excised DGGE bands: 'specialists'- found on only one host species, 'sponge associates'- found on multiple hosts but not in seawater, and 'generalists' from multiple hosts and seawater. Analogous to other high ersity systems, the degree of specificity of prokaryotes to host eukaryotes could have a potentially significant effect on estimates of marine microbial ersity.
Effect of coral-algal interactions on early life history processes in Pocillopora acuta in a highly disturbed coral reef system
Publisher: Frontiers Media SA
Date: 26-10-2018
Chemical Mediation of Ternary Interactions Between Marine Holobionts and Their Environment as Exemplified by the Red Alga Delisea pulchra
Publisher: Springer Science and Business Media LLC
Date: 25-04-2012
DOI: 10.1007/S10886-012-0119-5
Abstract: The need for animals and plants to control microbial colonization is important in the marine environment with its high densities of microscopic propagules and seawater that provides an ideal medium for their dispersal. In contrast to the traditional emphasis on antagonistic interactions of marine organisms with microbes, emerging studies lend support to the notion that health and performance of many marine organisms are functionally regulated and assisted by associated microbes, an ecological concept defined as a holobiont. While antimicrobial activities of marine secondary metabolites have been studied in great depth ex-situ, we are beginning to understand how some of these compounds function in an ecological context to maintain the performance of marine holobionts. The present article reviews two decades of our research on the red seaweed Delisea pulchra by addressing: the defense chemistry of this seaweed chemically-mediated interactions between the seaweed and its natural enemies and the negative influence of elevated seawater temperature on these interactions. Our understanding of these defense compounds and the functional roles they play for D. pulchra extends from molecular interactions with bacterial cell signaling molecules, to ecosystem-scale consequences of chemically-controlled disease and herbivory. Delisea pulchra produces halogenated furanones that antagonize the same receptor as acylated homoserine lactones (AHL)-a group of widespread intercellular communication signals among bacteria. Halogenated furanones compete with and inhibit bacterial cell-to-cell communication, and thus interfere with important bacterial communication-regulated processes, such as biofilm formation. In a predictable pattern that occurs at the ecological level of entire populations, environmental stress interferes with the production of halogenated furanones, causing downstream processes that ultimately result in disease of the algal holobiont.
Linking marine biology and biotechnology
Publisher: Elsevier BV
Date: 06-2002
DOI: 10.1016/S0958-1669(02)00311-7
Abstract: Studies of biological systems in which there is a direct link between the challenges faced by marine organisms and biotechnologies enable us to rationally search for active natural compounds and other novel biotechnologies. This approach is proving successful in developing new methods for the prevention of marine biofouling and for the identification of new lead compounds for the development of ultraviolet sunscreens.
Evidence for Acyl Homoserine Lactone Signal Production in Bacteria Associated with Marine Sponges
Publisher: American Society for Microbiology
Date: 07-2004
DOI: 10.1128/AEM.70.7.4387-4389.2004
Abstract: We report for the first time the production of acyl homoserine lactones (AHLs) by bacteria associated with marine sponges. Given the involvement of AHLs in bacterial colonization of many higher organisms, we speculate that such quorum sensing signals could play a part in interactions between sponges and the dense bacterial communities living within them.
Continental‐scale variation in seaweed host‐associated bacterial communities is a function of host condition, not geography
Publisher: Wiley
Date: 04-08-2015
Abstract: Interactions between hosts and associated microbial communities can fundamentally shape the development and ecology of 'holobionts', from humans to marine habitat-forming organisms such as seaweeds. In marine systems, planktonic microbial community structure is mainly driven by geography and related environmental factors, but the large-scale drivers of host-associated microbial communities are largely unknown. Using 16S-rRNA gene sequencing, we characterized 260 seaweed-associated bacterial and archaeal communities on the kelp Ecklonia radiata from three biogeographical provinces spanning 10° of latitude and 35° of longitude across the Australian continent. These phylogenetically and taxonomically erse communities were more strongly and consistently associated with host condition than geographical location or environmental variables, and a 'core' microbial community characteristic of healthy kelps appears to be lost when hosts become stressed. Microbial communities on stressed in iduals were more similar to each other among locations than those on healthy hosts. In contrast to biogeographical patterns of planktonic marine microbial communities, host traits emerge as critical determinants of associated microbial community structure of these holobionts, even at a continental scale.
Marine Biofilm Bacteria Evade Eukaryotic Predation by Targeted Chemical Defense
Publisher: Public Library of Science (PLoS)
Date: 23-07-2008
A global analysis of complexity–biodiversity relationships on marine artificial structures
Publisher: Wiley
Date: 20-10-2020
DOI: 10.1111/GEB.13202
Ultrastructure of the gland cells of the red alga Asparagopsis armata (Bonnemaisoniaceae)
Publisher: Wiley
Date: 25-05-2006
Genomic, metabolic and phenotypic variability shapes ecological differentiation and intraspecies interactions of Alteromonas macleodii
Publisher: Springer Science and Business Media LLC
Date: 21-01-2020
DOI: 10.1038/S41598-020-57526-5
Abstract: Ecological differentiation between strains of bacterial species is shaped by genomic and metabolic variability. However, connecting genotypes to ecological niches remains a major challenge. Here, we linked bacterial geno- and phenotypes by contextualizing pangenomic, exometabolomic and physiological evidence in twelve strains of the marine bacterium Alteromonas macleodii , illuminating adaptive strategies of carbon metabolism, microbial interactions, cellular communication and iron acquisition. In A. macleodii strain MIT1002, secretion of amino acids and the unique capacity for phenol degradation may promote associations with Prochlorococcus cyanobacteria. Strain 83-1 and three novel Pacific isolates, featuring clonal genomes despite originating from distant locations, have profound abilities for algal polysaccharide utilization but without detrimental implications for Ecklonia macroalgae. Degradation of toluene and xylene, mediated via a plasmid syntenic to terrestrial Pseudomonas , was unique to strain EZ55. Benzoate degradation by strain EC673 related to a chromosomal gene cluster shared with the plasmid of A. mediterranea EC615, underlining that mobile genetic elements drive adaptations. Furthermore, we revealed strain-specific production of siderophores and homoserine lactones, with implications for nutrient acquisition and cellular communication. Phenotypic variability corresponded to different competitiveness in co-culture and geographic distribution, indicating linkages between intraspecific ersity, microbial interactions and biogeography. The finding of “ecological micro ersity” helps understanding the widespread occurrence of A. macleodii and contributes to the interpretation of bacterial niche specialization, population ecology and biogeochemical roles.
Genetic diversity in threatened Posidonia australis seagrass meadows
Publisher: Springer Science and Business Media LLC
Date: 28-01-2014
Localisation and surface quantification of secondary metabolites in the red alga Delisea pulchra
Publisher: Springer Science and Business Media LLC
Date: 11-05-1999
Sex, Scavengers, and Chaperones: Transcriptome Secrets of DivergentSymbiodiniumThermal Tolerances
Publisher: Oxford University Press (OUP)
Date: 14-06-2016
Characterisation of microsatellite loci in the subtidal habitat-forming alga, Phyllospora comosa (Phaeophyceae, Fucales)
Publisher: Springer Science and Business Media LLC
Date: 28-10-2007
Chemical defence against bacteria in the red alga Asparagopsis armata: linking structure with function
Publisher: Inter-Research Science Center
Date: 11-01-2006
DOI: 10.3354/MEPS306087
Using meta‐omics of contaminated sediments to monitor changes in pathways relevant to climate regulation
Publisher: Wiley
Date: 13-12-2018
Abstract: Microbially mediated biogeochemical processes are crucial for climate regulation and may be disrupted by anthropogenic contaminants. To better manage contaminants, we need tools that make real-time causal links between stressors and altered microbial functions, and the potential consequences for ecosystem services such as climate regulation. In a manipulative field experiment, we used metatranscriptomics to investigate the impact of excess organic enrichment and metal contamination on the gene expression of nitrogen and sulfur metabolisms in coastal sediments. Our gene expression data suggest that excess organic enrichment results in (i) higher transcript levels of genes involved in the production of toxic ammonia and hydrogen sulfide and (ii) lower transcript levels associated with the degradation of a greenhouse gas (nitrous oxide). However, metal contamination did not have any significant impact on gene expression. We reveal the genetic mechanisms that may lead to altered productivity and greenhouse gas production in coastal sediments due to anthropogenic contaminants. Our data highlight the applicability of metatranscriptomics as a management tool that provides an immense breadth of information and can identify potentially impacted process measurements that need further investigation.
Recruitment of the sea urchin Heliocidaris erythrogramma and the distribution and abundance of inducing bacteria in the field
Publisher: Inter-Research Science Center
Date: 29-09-2008
DOI: 10.3354/AME01239
Financial and Institutional Support Are Important for Large-Scale Kelp Forest Restoration
Publisher: Frontiers Media SA
Date: 25-09-2020
Erratum: Fimbrolide-coated antimicrobial lenses: their in vitro and in vivo effects (Optometry and Vision Science (2008) 85 (292-300)
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2008
Corrigendum to “Increasing microhabitat complexity on seawalls can reduce fish predation on native oysters” [Ecol. Eng. 120 (2018) 637–644](S0925857417302938)(10.1016/j.ecoleng.2017.05.030)
Publisher: Elsevier BV
Date: 06-2019
A global atlas of the environmental risk of marinas on water quality
Publisher: Elsevier BV
Date: 12-2019
Bacterial community assembly based on functional genes rather than species
Publisher: Proceedings of the National Academy of Sciences
Date: 08-08-2011
Abstract: The principles underlying the assembly and structure of complex microbial communities are an issue of long-standing concern to the field of microbial ecology. We previously analyzed the community membership of bacterial communities associated with the green macroalga Ulva australis , and proposed a competitive lottery model for colonization of the algal surface in an attempt to explain the surprising lack of similarity in species composition across different algal s les. Here we extend the previous study by investigating the link between community structure and function in these communities, using metagenomic sequence analysis. Despite the high phylogenetic variability in microbial species composition on different U. australis (only 15% similarity between s les), similarity in functional composition was high (70%), and a core of functional genes present across all algal-associated communities was identified that were consistent with the ecology of surface- and host-associated bacteria. These functions were distributed widely across a variety of taxa or phylogenetic groups. This observation of similarity in habitat (niche) use with respect to functional genes, but not species, together with the relative ease with which bacteria share genetic material, suggests that the key level at which to address the assembly and structure of bacterial communities may not be “species” (by means of rRNA taxonomy), but rather the more functional level of genes.
Contrasting distributions of bacteriophages and eukaryotic viruses from contaminated coastal sediments
Publisher: Wiley
Date: 19-10-2018
Abstract: Viruses are ubiquitous, abundant and play an important role in all ecosystems. Here, we advance understanding of coastal sediment viruses by exploring links in the composition and abundance of sediment viromes to environmental stressors and sediment bacterial communities. We collected sediment from contaminated and reference sites in Sydney Harbour and used metagenomics to analyse viral community composition. The proportion of phages at contaminated sites was significantly greater than phages at reference sites, whereas eukaryotic viruses were relatively more abundant at reference sites. We observed shifts in viral and bacterial composition between contaminated and reference sites of a similar magnitude. Models based on sediment characteristics revealed that total organic carbon in the sediments explained most of the environmental stress-related variation in the viral dataset. Our results suggest that the presence of anthropogenic contaminants in coastal sediments could be influencing viral community composition with potential consequences for associated hosts and the environment.
Seaweedherbivore interactions at a small scale: direct tests of feeding deterrence by filamentous algae
Publisher: Inter-Research Science Center
Date: 05-10-2006
DOI: 10.3354/MEPS323001
Effect of interspecific competition on trait variation in P haeobacter inhibens biofilms
Publisher: Wiley
Date: 27-04-2016
Abstract: Interspecific competition between bacteria shapes community dynamics, causing evolutionary changes that affect life history traits. Here, we studied the role of interspecific competition on the generation of trait ersity using a two-species model system of marine, surface-associated bacteria. Bacterial biofilms of Phaeobacter inhibens were established alone or in competition with Pseudoalteromonas tunicata and phenotypic traits of dispersal cells were assessed during biofilm development. P. inhibens dispersal isolates from competition biofilms displayed less phenotypic variation, were superior competitors, were less susceptible to predation, and reached higher planktonic biomass than isolates from noncompetition biofilms. Moreover, the maintenance of competitive ability exhibited by in idual dispersal isolates from competition biofilms did not result in an obvious reduction (measured as a negative trait correlation) in other traits, but was rather positively correlated with planktonic growth. However, where negative correlations between traits were found, they were exhibited by in iduals derived from noncompetitive biofilms, whose populations also had a higher degree of trait variation than those from biofilms experiencing competition. Our observations indicate that interspecific competition during biofilm formation is important for maintaining both competitive ability and affects variation in ecologically relevant traits. Given that most bacteria in biofilms exist in erse, multispecies communities, an understanding of how bacteria respond to biotic factors such as interspecific competition is critical for understanding the dynamics of bacterial populations in both ecological and evolutionary time.
Relative importance of natural cues and substrate morphology for settlement of the New Zealand Greenshell™ mussel, Perna canaliculus
Publisher: Elsevier BV
Date: 09-2011
Legacy Metal Contaminants and Excess Nutrients in Low Flow Estuarine Embayments Alter Composition and Function of Benthic Bacterial Communities
Publisher: Frontiers Media SA
Date: 08-10-2021
DOI: 10.3389/FMICB.2021.661177
Abstract: Coastal systems such as estuaries are threatened by multiple anthropogenic stressors worldwide. However, how these stressors and estuarine hydrology shape benthic bacterial communities and their functions remains poorly known. Here, we surveyed sediment bacterial communities in poorly flushed embayments and well flushed channels in Sydney Harbour, Australia, using 16S rRNA gene sequencing. Sediment s les were collected monthly during the Austral summer-autumn 2014 at increasing distance from a large storm drain in each channel and embayment. Bacterial communities differed significantly between sites that varied in proximity to storm drains, with a gradient of change apparent for sites within embayments. We explored this pattern for embayment sites with analysis of RNA-Seq gene expression patterns and found higher expression of multiple genes involved in bacterial stress response far from storm drains, suggesting that bacterial communities close to storm drains may be more tolerant of localised anthropogenic stressors. Several bacterial groups also differed close to and far from storm drains, suggesting their potential utility as bioindicators to monitor contaminants in estuarine sediments. Overall, our study provides useful insights into changes in the composition and functioning of benthic bacterial communities as a result of multiple anthropogenic stressors in differing hydrological conditions.
Use of solid-phase extraction to enable enhanced detection of acyl homoserine lactones (AHLs) in environmental samples
Publisher: Springer Science and Business Media LLC
Date: 05-08-2005
DOI: 10.1007/S00216-005-3387-X
Abstract: A challenge for understanding the role of bacterial cell-cell signalling in the environment is the detection of those signals, which are often present in low (nmol L(-1)) concentrations. We describe here a simple purification method, solid-phase extraction (SPE), for increasing the sensitivity of detection for one such group of signals, acyl homoserine lactones (AHLs), in environmental s les. Spiking of dried marine sponge tissue (Stylinos sp.) with AHLs resulted in detection down to 0.01 ppm for 3-oxo-hexanoyl homoserine lactone (3-oxo C6-HSL) and 1 ppm for hexanoyl homoserine lactone (C6-HSL). Compared with liquid extraction methods use of SPE resulted in twofold and tenfold improvements in sensitivity, respectively.
Genomic vulnerability of a dominant seaweed points to future‐proofing pathways for Australia's underwater forests
Publisher: Wiley
Date: 16-02-2021
DOI: 10.1111/GCB.15534
SEX AND LIFE‐HISTORY STAGE ALTER HERBIVORE RESPONSES TO A CHEMICALLY DEFENDED RED ALGA
Publisher: Wiley
Date: 05-2008
DOI: 10.1890/07-0248.1
Abstract: Intraspecific variation in resistance to herbivory among genders and life-history phases of primary producers can significantly alter the ecological and evolutionary consequences of plant-herbivore interactions. Seaweeds (macroalgae) with complex life histories have multiple distinct phases with associated variation in traits that can potentially lead to differences in resistance to consumers and provide a unique system in which to simultaneously test the effects of sex and life-history stage on herbivory. We tested the susceptibility to grazing of the three life-history stages and separate sexes of the chemically defended red alga Asparagopsis armata against the sea hare Aplysia parvula, and we related this to the plant quality traits of different stages and genders. Differences in nutrient content and halogenated secondary metabolites between life-history phases were highly sex dependent. Male gametophytes had a low concentration of secondary metabolites and the highest nutrient content. The highest secondary metabolite content was found within the female gametophyte, in the wall of the reproductive structures (cystocarps) that contain the microscopic carposporophyte phase. Feeding choices by A. parvula were consistent with differences in algal quality and defense and resulted in the haploid male gametophytes being the most preferred food type. The diploid carposporophyte found inside the chemically rich cystocarps was the least consumed life-history stage. Selective herbivory of male gametophytes by A. parvula is consistent with an observed shift in gametophyte sex ratio in the field from unity at the beginning of the reproductive season to female bias at the end. The variation in susceptibility to herbivory found between sex and life-history stages of A. armata represents the first ex le of sex-biased consumption in seaweeds and may contribute to the maintenance of complex life histories such as those found in red algae.
Attenuation of Pseudomonas aeruginosa virulence by quorum sensing inhibitors
Publisher: Wiley
Date: 08-2003
DOI: 10.1093/EMBOJ/CDG366
Spatial variability of microbial assemblages associated with a dominant habitat-forming seaweed
Publisher: Frontiers Media SA
Date: 26-03-2015
Feeding habits of range-shifting herbivores: Tropical surgeonfishes in a temperate environment
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/MF14208
Abstract: A widely documented impact of ocean warming is the poleward shift in species’ distributions. This includes the global movement of tropical fishes into temperate rocky reefs. The ecological impacts of such range extensions are, however, largely unknown. We compared the feeding habits of herbivorous tropical surgeonfishes (Acanthuridae) to that of warm-temperate surgeonfishes near Sydney, Australia. The abundance of tropical surgeonfishes peaked during warmer months before they became locally extinct in winter. Comparisons of bite rates in the field between tropical (Acanthurus triostegus, Acanthurus dussumieri) and warm-temperate (Prionurus microlepidotus, Prionurus maculatus) surgeonfishes showed a significant effect of schooling, with both groups feeding most intensely in monospecific schools. In aquarium feeding trials, tropical surgeonfishes consumed more algae than their warm-temperate counterparts at both high and low temperatures (25 and 20°C), and had higher bite rates at 25°C than at 20°C. A. dussumieri also had significantly higher consumption rates on brown algal recruits at warmer temperatures. We further compared gut indices and jaw-lever ratios among the four focal species, and found no consistent pattern between tropical and warm-temperate fishes. This study suggests that the continued intrusion of tropical surgeonfishes in temperate reefs will result in increased herbivory, as a result of both higher herbivore abundance and higher consumption rates per capita by tropical species.
DEMOGRAPHIC CONSEQUENCES OF AN ONTOGENETIC SHIFT BY A SEA URCHIN IN RESPONSE TO HOST PLANT CHEMISTRY
Publisher: Wiley
Date: 05-2004
DOI: 10.1890/02-4083
Related Organisations
No related organisations have been discovered for Peter Steinberg.
Related Funding Activities
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0775746
Start Date: 07-2007
End Date: 07-2010
Amount: $102,000.00
Funder: Australian Research Council
View Funded ActivitySuper Science Fellowships - Grant ID: FS110200029
Start Date: 01-2012
End Date: 12-2016
Amount: $556,800.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE140100055
Start Date: 2014
End Date: 12-2015
Amount: $290,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP170100023
Start Date: 2017
End Date: 06-2020
Amount: $385,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE130100019
Start Date: 2013
End Date: 12-2014
Amount: $580,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE170100007
Start Date: 2017
End Date: 12-2017
Amount: $552,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0773476
Start Date: 2007
End Date: 12-2009
Amount: $313,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP160100836
Start Date: 11-2016
End Date: 12-2021
Amount: $280,687.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP1096464
Start Date: 2010
End Date: 12-2013
Amount: $500,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP0668235
Start Date: 12-2006
End Date: 12-2011
Amount: $1,611,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP1096481
Start Date: 2010
End Date: 12-2012
Amount: $310,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP0455677
Start Date: 07-2004
End Date: 08-2008
Amount: $266,208.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0211584
Start Date: 02-2002
End Date: 06-2005
Amount: $231,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP140102776
Start Date: 2014
End Date: 03-2017
Amount: $458,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0667033
Start Date: 2006
End Date: 12-2008
Amount: $259,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP180104041
Start Date: 2018
End Date: 06-2022
Amount: $443,024.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE0668039
Start Date: 2006
End Date: 12-2006
Amount: $160,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP100100128
Start Date: 2010
End Date: 12-2014
Amount: $1,237,600.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP130100364
Start Date: 04-2014
End Date: 04-2017
Amount: $668,057.00
Funder: Australian Research Council
View Funded Activity