ORCID Profile
0000-0002-3507-1234
Current Organisation
UNSW Sydney
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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)
Marine and Estuarine Ecology (incl. Marine Ichthyology) | Ecology | Phycology (incl. Marine Grasses) | Environmental Rehabilitation (excl. Bioremediation) | Global Change Biology | Microbial Ecology | Ecology | Ecosystem Function | Environmental Science and Management | Environmental Impact Assessment | Landscape Ecology | Environmental rehabilitation and restoration | Marine and estuarine ecology (incl. marine ichthyology) |
ANZSRC Socio-Economic Objective (SEO)
Marine Flora, Fauna and Biodiversity | Ecosystem Adaptation to Climate Change | Ecosystem Assessment and Management of Coastal and Estuarine Environments | Effects of Climate Change and Variability on Australia (excl. Social Impacts) | Coastal and Estuarine Flora, Fauna and Biodiversity | Rehabilitation of Degraded Coastal and Estuarine Environments | Ecosystem Assessment and Management of Marine Environments
Related Links
Publications
Kelp Forest Restoration in Australia
Publisher: Frontiers Media SA
Date: 14-02-2020
Convictfish on the move: variation in growth and trophic niche space along a latitudinal gradient
Publisher: Oxford University Press (OUP)
Date: 30-06-2019
Abstract: The range expansion of tropical fish into temperate waters is increasing markedly in response to climate change. Range-expanding fish encounter novel diets and environments, but we know little about how these conditions facilitate or hinder distribution shifts. Here, we quantified relative growth rate, morphometric condition and trophic niche of juvenile Acanthurus triostegus, a dominant range-expanding tropical surgeonfish, at four locations across 10° of latitude off eastern Australia. We related these metrics to differences in temperature and nutritional quality of dominant seaweeds and the epilithic algal matrix. Temperate food sources were richer in nitrogen than tropical diets. Stable isotope analysis (δ13 carbon and δ15 nitrogen) of fish muscle revealed a large trophic niche breadth at the highest latitude indicating a generalist foraging strategy, and more nitrogen-enriched isotopic signatures compared to tropical regions. Fish length was strongly correlated to δ13C in all regions, suggesting an ontogenetic shift in diet independent of latitude. Despite temperature differences of 4°C, fish growth and body condition were similar across tropical and temperate regions. These results suggest that more nutritious temperate diets may compensate for the effects of cooler water temperatures. Neither summer water temperatures nor dietary factors appear to limit the success of juvenile tropical vagrants as they continue to expand their range along eastern Australia.
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.
Financial and institutional support are important for large-scale kelp forest restoration
Publisher: California Digital Library (CDL)
Date: 21-04-2020
Plant defences and the role of epibiosis in mediating within-plant feeding choices of seagrass consumers
Publisher: Springer Science and Business Media LLC
Date: 04-11-2010
DOI: 10.1007/S00442-010-1830-Y
Abstract: Within-plant variation in susceptibility to herbivory can significantly influence the ecological and evolutionary consequences of plant-herbivore interactions. Seagrasses are marine angiosperms characterised by substantial intra-in idual differences in multiple traits, such as nutrients, chemical and structural defences and epibiotic load, all of which can strongly influence herbivore preferences. We quantified the within-plant feeding choices of the two main consumers of the temperate seagrass Posidonia oceanica--the fish Sarpa salpa and the sea urchin Paracentrotus lividus--and determined the plant traits that explained their foraging strategies. We found strong within-plant heterogeneity in both seagrass susceptibility to herbivory and chemical composition, but different consumers exhibited contrasting feeding choices. S. salpa preferred the most nutritious and chemically defended younger leaves, suggesting a full adaptation to consuming this macrophyte and a greater impact of this herbivore on the plant. In contrast, P. lividus consistently preferred the older leaves covered by epibionts, probably attenuating the relative impact of this consumer and helping to explain the weak effects usually recorded for this echinoid in undisturbed meadows. Artificial diet experiments showed that morphology and fine-scale structural defences were the primary determinant of urchin feeding choices, with nutrient content and chemical defences being of secondary importance. Epibiosis did not strongly influence fish feeding, but it did have a strong 'shared-doom' effect on urchin consumption. This effect was driven by a distinct preference towards a mixed diet that included both host tissues and their epibiotic community.
Managing consequences of climate-driven species redistribution requires integration of ecology, conservation and social science
Publisher: Wiley
Date: 06-2018
DOI: 10.1111/BRV.12344
Abstract: Climate change is driving a pervasive global redistribution of the planet's species. Species redistribution poses new questions for the study of ecosystems, conservation science and human societies that require a coordinated and integrated approach. Here we review recent progress, key gaps and strategic directions in this nascent research area, emphasising emerging themes in species redistribution biology, the importance of understanding underlying drivers and the need to anticipate novel outcomes of changes in species ranges. We highlight that species redistribution has manifest implications across multiple temporal and spatial scales and from genes to ecosystems. Understanding range shifts from ecological, physiological, genetic and biogeographical perspectives is essential for informing changing paradigms in conservation science and for designing conservation strategies that incorporate changing population connectivity and advance adaptation to climate change. Species redistributions present challenges for human well-being, environmental management and sustainable development. By synthesising recent approaches, theories and tools, our review establishes an interdisciplinary foundation for the development of future research on species redistribution. Specifically, we demonstrate how ecological, conservation and social research on species redistribution can best be achieved by working across disciplinary boundaries to develop and implement solutions to climate change challenges. Future studies should therefore integrate existing and complementary scientific frameworks while incorporating social science and human-centred approaches. Finally, we emphasise that the best science will not be useful unless more scientists engage with managers, policy makers and the public to develop responsible and socially acceptable options for the global challenges arising from species redistributions.
Climate change: underwater forest decline
Publisher: Wiley
Date: 06-03-2019
DOI: 10.1111/AEC.12730
Accelerating Tropicalization and the Transformation of Temperate Seagrass Meadows
Publisher: Oxford University Press (OUP)
Date: 14-09-2016
Does restoration of a habitat‐forming seaweed restore associated faunal diversity?
Publisher: Wiley
Date: 26-10-2015
DOI: 10.1111/REC.12292
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
Genotypic richness predicts phenotypic variation in an endangered clonal plant
Publisher: PeerJ
Date: 18-02-2016
DOI: 10.7717/PEERJ.1633
Abstract: Declines in genetic ersity within a species can affect the stability and functioning of populations. The conservation of genetic ersity is thus a priority, especially for threatened or endangered species. The importance of genetic variation, however, is dependent on the degree to which it translates into phenotypic variation for traits that affect in idual performance and ecological processes. This is especially important for predominantly clonal species, as no single clone is likely to maximise all aspects of performance. Here we show that intraspecific genotypic ersity as measured using microsatellites is a strong predictor of phenotypic variation in morphological traits and shoot productivity of the threatened, predominantly clonal seagrass Posidonia australis , on the east coast of Australia. Biomass and surface area variation was most strongly predicted by genotypic richness, while variation in leaf chemistry (phenolics and nitrogen) was unrelated to genotypic richness. Genotypic richness did not predict tissue loss to herbivores or epiphyte load, however we did find that increased herbivore damage was positively correlated with allelic richness. Although there was no clear relationship between higher primary productivity and genotypic richness, variation in shoot productivity within a meadow was significantly greater in more genotypically erse meadows. The proportion of phenotypic variation explained by environmental conditions varied among different genotypes, and there was generally no variation in phenotypic traits among genotypes present in the same meadows. Our results show that genotypic richness as measured through the use of presumably neutral DNA markers does covary with phenotypic variation in functionally relevant traits such as leaf morphology and shoot productivity. The remarkably long lifespan of in idual Posidonia plants suggests that plasticity within genotypes has played an important role in the longevity of the species. However, the strong link between genotypic and phenotypic variation suggests that a range of genotypes is still the best case scenario for adaptation to and recovery from predicted environmental change.
Restore or Redefine: Future Trajectories for Restoration
Publisher: Frontiers Media SA
Date: 17-04-2020
Seagrass tolerance to herbivory under increased ocean temperatures
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.MARPOLBUL.2013.08.010
Abstract: Climate change is acknowledged as a major threat to marine ecosystems, but the effect of temperature on species interactions remains poorly understood. We quantified the effects of long-term warming on plant-herbivore interactions of a dominant seagrass, Zostera muelleri. Growth, herbivory and tolerance to damage were compared between a meadow warmed by the thermal plume from a power station for 30 years (2-3 °C above background temperatures) and three control locations. Leaf growth rates and tissue loss were spatially variable but unrelated to temperature regimes. Natural herbivory was generally low. Simulated herbivory experiments showed that the tolerance of Z. muelleri to defoliation did not differ between warm and unimpacted meadows, with damaged and undamaged plants maintaining similar growth rates irrespective of temperature. These results suggest that the ability of temperate Z. muelleri to tolerate herbivory is not strongly influenced by warming, and this species may be relatively resilient to future environmental change.
The Kelp Forest Alliance: A Global Community of Practice to Understand, Advise, and Motivate Kelp Forest Conservation and Restoration
Publisher: Wiley
Date: 25-10-2022
DOI: 10.1002/LOB.10528
Resilience of seagrass populations to thermal stress does not reflect regional differences in ocean climate
Publisher: Wiley
Date: 14-12-2021
DOI: 10.1111/NPH.17885
Abstract: The prevalence of local adaptation and phenotypic plasticity among populations is critical to accurately predicting when and where climate change impacts will occur. Currently, comparisons of thermal performance between populations are untested for most marine species or overlooked by models predicting the thermal sensitivity of species to extirpation. Here we compared the ecological response and recovery of seagrass populations ( Posidonia oceanica ) to thermal stress throughout a year‐long translocation experiment across a 2800‐km gradient in ocean climate. Transplants in central and warm‐edge locations experienced temperatures 29°C, representing thermal anomalies 5°C above long‐term maxima for cool‐edge populations, 1.5°C for central and 1°C for warm‐edge populations. Cool‐edge, central and warm‐edge populations differed in thermal performance when grown under common conditions, but patterns contrasted with expectations based on thermal geography. Cool‐edge populations did not differ from warm‐edge populations under common conditions and performed significantly better than central populations in growth and survival. Our findings reveal that thermal performance does not necessarily reflect the thermal geography of a species. We demonstrate that warm‐edge populations can be less sensitive to thermal stress than cooler, central populations suggesting that Mediterranean seagrasses have greater resilience to warming than current paradigms suggest.
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.
Macrograzers strongly influence patterns of epiphytic assemblages in seagrass meadows
Publisher: Elsevier BV
Date: 11-2007
Advances in approaches to seagrass restoration in Australia
Publisher: Wiley
Date: 2021
DOI: 10.1111/EMR.12452
Abstract: Three case studies involving two temperate Australian seagrass species – Pondweed ( Ruppia tuberosa ) and Ribbon Weed ( Posidonia australis ) – highlight different approaches to their restoration. Seeds and rhizomes were used in three collaborative programmes to promote new approaches to scale up restoration outcomes.
Using the background of fish photographs to quantify habitat composition in marine ecosystems
Publisher: Inter-Research Science Center
Date: 28-04-2022
DOI: 10.3354/MEPS14027
Abstract: Citizen science initiatives that collect opportunistic photos, or recordings, of living organisms (e.g. iNaturalist) are increasingly recognized for their importance in monitoring bio ersity. These projects are focussed primarily on recording the occurrence of in idual species in space and time. Each photo potentially also contains additional valuable information. Here, we explored the amount and potential value of background information captured in fish photographs as a method to characterise reef habitats. The habitat in the background of fish photographs shared on iNaturalist was analysed for 6 sites across Australia. To measure accuracy of the habitat data captured in the iNaturalist photos, the habitat composition of each site was compared to standardised photo-quadrats from the citizen science project Reef Life Survey (RLS). Across all sites, 70-85% of the fish photographs from iNaturalist contained discernible biotic habitat in the background. Habitat composition as measured from the background of opportunistic fish photographs was similar to those of standardised surveys from RLS. In the face of rapid environmental change, opportunistic photographs collected by recreational ers represent a complementary way to rapidly and cost-effectively collect habitat data at more reefs and more frequently than is generally feasible with standardised scientific surveys.
Branching coral as a macroalgal refuge in a marginal coral reef system
Publisher: Springer Science and Business Media LLC
Date: 16-02-2010
Predation domes: In‐situ field assays to measure predatory behaviours by fish
Publisher: Wiley
Date: 22-06-2023
Abstract: Biotic interactions such as predation are difficult ecological processes to quantify in the wild. This is especially the case in the marine environment due to logistical difficulties in capturing animal behaviour. Common approaches use aquarium‐based experiments, live‐tethering, or assays with bait as proxies for quantifying predation pressure. However, these methods often fail to account for natural interactions between species in the wild and may raise ethical and animal welfare concerns. We designed a novel field‐based method to quantify predator–prey interactions for marine fishes. The “predation dome” is a clear acrylic aquarium that contains a live fish. The dome is filmed and, in contrast to other methods, it allows for natural olfactory and visual cues, and the prey fish is returned to the wild after the assay. Here, we provide a step‐by‐step guide on building and deploying the predation dome in the wild. To demonstrate its use, we quantified predation pressure using the domes in two tropical and two temperate locations. Piscivores were attracted to the domes and displayed predatory behaviours such as circling or striking. Although the overall number of predatory attacks did not differ among locations, predation domes revealed higher predation pressure by piscivores at the tropical locations in comparison to temperate reefs. Our results show that predation domes represent an ethical and complementary approach to measure predation that may better represent piscivory as compared to other behaviours. Predation domes can be also used to measure other biotic interactions such as territorial defence or courtship.
Habitat Provision and Erosion Are Influenced by Seagrass Meadow Complexity: A Seascape Perspective
Publisher: MDPI AG
Date: 17-01-2023
DOI: 10.3390/D15020125
Abstract: Habitat complexity plays a critical role in shaping biotic assemblages and ecosystem processes. While the impacts of large differences in habitat complexity are often well understood, we know less about how subtle differences in structure affect key ecosystem functions or properties such as bio ersity and biomass. The late-successional seagrass Posidonia australis creates vital habitat for erse fauna in temperate Australia. Long-term human impacts have led to the decline of P. australis in some estuaries of eastern Australia, where it is now classified as an endangered ecological community. We examined the influence of P. australis structural complexity at small (seagrass density) and large (meadow fragmentation) spatial scales on fish and epifauna communities, predation and sediment erosion. Fine-scale spatially balanced s ling was evenly distributed across a suite of environmental covariates within six estuaries in eastern Australia using the Generalised Random Tessellation Structures approach. We found reduced erosion in areas with higher P. australis density, greater abundance of fish in more fragmented areas and higher fish richness in vegetated areas further from patch edges. The abundance of epifauna and fish, and fish species richness were higher in areas with lower seagrass density (seagrass density did not correlate with distance to patch edge). These findings can inform seagrass restoration efforts by identifying meadow characteristics that influence ecological functions and processes.
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.
Congruence of intraspecific variability in leaf traits for two co-occurring estuarine angiosperms
Publisher: Springer Science and Business Media LLC
Date: 21-04-2016
Experimental evidence of chemical deterrence against multiple herbivores in the seagrass Posidonia oceanica
Publisher: Inter-Research Science Center
Date: 07-08-2007
DOI: 10.3354/MEPS06885
Genotypic diversity and short-term response to shading stress in a threatened seagrass: Does low diversity mean low resilience?
Publisher: Frontiers Media SA
Date: 14-08-2017
Role of fish herbivory in structuring the vertical distribution of canopy algae Cystoseira spp. in the Mediterranean Sea
Publisher: Inter-Research Science Center
Date: 26-01-2009
DOI: 10.3354/MEPS07778
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.
Interactive effects of depth and marine protection on predation and herbivory patterns
Publisher: Inter-Research Science Center
Date: 29-03-2012
DOI: 10.3354/MEPS09599
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.
Using near infra red reflectance spectroscopy (NIRS) to quantify tissue composition in the seagrass Posidonia australis
Publisher: Elsevier BV
Date: 11-2013
Operation Crayweed: Ecological and sociocultural aspects of restoring Sydney’s underwater forests
Publisher: Wiley
Date: 05-2020
DOI: 10.1111/EMR.12413
Diversity among Macroalgae-Consuming Fishes on Coral Reefs: A Transcontinental Comparison
Publisher: Public Library of Science (PLoS)
Date: 20-09-2012
Playing to the Positives: Using Synergies to Enhance Kelp Forest Restoration
Publisher: Frontiers Media SA
Date: 10-07-2020
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.
Identity and behaviour of herbivorous fish influence large-scale spatial patterns of macroalgal herbivory in a coral reef
Publisher: Inter-Research Science Center
Date: 22-05-2013
DOI: 10.3354/MEPS10262
Climate‐driven ‘species‐on‐the‐move’ provide tangible anchors to engage the public on climate change
Publisher: Wiley
Date: 18-07-2023
DOI: 10.1002/PAN3.10495
Abstract: Over recent decades, our understanding of climate change has accelerated greatly, but unfortunately, observable impacts have increased in tandem. Both mitigation and adaptation have not progressed at the level or scale warranted by our collective knowledge on climate change. More effective approaches to engage people on current and future anthropogenic climate change effects are urgently needed. Here, we show how species whose distributions are shifting in response to climate change, that is, ‘species‐on‐the‐move’, present an opportunity to engage people with climate change by linking to human values, and our deep connections with the places in which we live, in a locally relevant yet globally coherent narrative. Species‐on‐the‐move can impact ecosystem structure and function, food security, human health, livelihoods, culture and even the climate itself through feedback to the climate system, presenting a wide variety of potential pathways for people to understand that climate change affects them personally as in iduals. Citizen science focussed on documenting changes in bio ersity is one approach to foster a deeper engagement on climate change. However, other possible avenues, which may offer potential to engage people currently unconnected with nature, include arts, games or collaborations with rural agriculture (e.g. new occurrences of pest species) or fisheries organisations (e.g. shifting stocks) or healthcare providers (e.g. changing distributions of disease vectors). Through the importance we place on the aspects of life impacted by the redistribution of species around us, species‐on‐the‐move offer emotional pathways to connect with people on the complex issue of climate change in profound ways that have the potential to engender interest and action on climate change. Read the free Plain Language Summary for this article on the Journal blog.
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
Using genomics to design and evaluate the performance of underwater forest restoration
Publisher: Wiley
Date: 23-07-2020
Variation in multiple traits of vegetative and reproductive seagrass tissues influences plant–herbivore interactions
Publisher: Springer Science and Business Media LLC
Date: 22-11-2006
DOI: 10.1007/S00442-006-0606-X
Abstract: Plant-herbivore interactions have strong ecological and evolutionary consequences, but have been traditionally overlooked in marine higher plants. Despite recent advances in seagrass ecology that highlight the importance of herbivory, the mechanisms that regulate the feeding behaviour of seagrass consumers remain largely unknown. Herbivores have been shown to reduce the sexual reproductive success of seagrasses through direct consumption of inflorescences and seeds, but we know little about intraspecific variation in susceptibility to grazing of different seagrass tissues. We contrasted the relative palatability of reproductive and vegetative tissues of the temperate seagrass Posidonia oceanica in the field, and we assessed the feeding preferences among these tissues of the main consumers of the plant, the fish Sarpa salpa and the urchin Paracentrotus lividus. Moreover, we identified the plant traits that explained the observed feeding behaviour. We provide strong evidence for herbivore selectivity among seagrass tissues. In the field, 70-90% of inflorescences were damaged by herbivores compared to 3-60% of leaves of similar age. In feeding assays, the urchin P. lividus showed over a twofold preference for reproductive tissue at various stages of development. By contrast, we detected no feeding activity on either leaves or inflorescences from the fish S. salpa, which is known to migrate to deeper waters soon after flowering starts and during the period of fruit maturation. Despite being the preferred food of urchins, inflorescences were chemically defended, had higher levels of phenolics and lower nutrient and calorific content than leaves. We experimentally demonstrated that leaf structural defences are the primary factor in determining urchin feeding preferences. Removal of plant structure results in a drastic shift in urchin selectivity towards the most nutritious and less chemically defended leaf tissue, indicating that multiple mechanisms of defence to herbivory may coexist in seagrasses.
A new resource for monitoring reef ecosystems: The background of recreational diver photographs contains valuable habitat data
Publisher: Wiley
Date: 18-10-2023
Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 31-03-2017
Abstract: Distributions of Earth's species are changing at accelerating rates, increasingly driven by human-mediated climate change. Such changes are already altering the composition of ecological communities, but beyond conservation of natural systems, how and why does this matter? We review evidence that climate-driven species redistribution at regional to global scales affects ecosystem functioning, human well-being, and the dynamics of climate change itself. Production of natural resources required for food security, patterns of disease transmission, and processes of carbon sequestration are all altered by changes in species distribution. Consideration of these effects of bio ersity redistribution is critical yet lacking in most mitigation and adaptation strategies, including the United Nation's Sustainable Development Goals.
Tropicalisation of temperate reefs: Implications for ecosystem functions and management actions
Publisher: Wiley
Date: 11-03-2019
Tropicalization unlocks novel trophic pathways and enhances secondary productivity in temperate reefs
Publisher: Wiley
Date: 11-01-2022
Abstract: The structure of ecological communities is rapidly changing across the globe due to climate‐mediated shifts in species distributions, with novel ecosystem states emerging as new species become dominant. While it is clear that such changes restructure habitat properties and their associated assemblages, how new nutritional resources and consumers may affect the ecosystem trophic structure and energetic dynamics remains poorly resolved. Here, we investigate how the reconfiguration of tropicalized reefs—that is, temperate ecosystems receiving an influx of tropical species—affects the availability of nutritional resources and energy flow through herbivore‐based trophic pathways. To do so, we quantified changes in algal and detrital resources along a tropicalization gradient in eastern Australia. We also estimated energy flow towards herbivorous fishes by quantifying their standing biomass (kg/ha), productivity (kg ha −1 day −1 ), and biomass turnover (% day −1 ), using an in idual‐level modelling approach that combines estimates of fish growth rates and mortality. Along the gradient, tropicalized reefs had relatively higher amounts of palatable algal turfs and detrital particulates compared to non‐tropicalized sites. Feeding intensity by herbivorous fishes was also c . 400 times higher on tropicalized reefs, with tropical turf‐cropping surgeon fishes being responsible for % of the feeding rates. Turf‐driven trophic pathways underpinned virtual all ( %) of the biomass produced by tropical fishes, which contributed up to 63% of the total herbivorous fish standing biomass and 86% of the productivity despite only representing 35% of the abundance. Turfs also fuelled most of the secondary productivity of tropical fishes on tropicalized reefs across Australia's western tropical–temperate transition zone, although their overall productivity was ~5 times lower. This is possibly due to turfs there containing elevated sediment loads, which dilute the nutritional quality of turf‐based resources, as well as other differences in the biogeographical context. We propose that algal turfs are central drivers of ecosystem energetic shifts on temperate reefs as they become tropicalized because they support novel algal and detrital trophic pathways that enhance secondary productivity and biomass turnover. Our results also suggest that turf characteristics such as organic content or sediment load may emerge as increasingly important drivers of energy flow in temperate locations where turfs dominate benthic cover. A free Plain Language Summary can be found within the Supporting Information of this article.
How to quantify algal turf sediments and particulates on tropical and temperate reefs: An overview
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.MARENVRES.2022.105673
Abstract: Algal turfs are the most abundant benthic covering on reefs in many shallow-water marine ecosystems. The particulates and sediments bound within algal turfs can influence a multitude of functions within these ecosystems. Despite the global abundance and importance of algal turfs, comparison of algal turf-bound sediments is problematic due to a lack of standardisation across collection methods. Here we provide an overview of three methods (vacuum s ling, airlift s ling, and TurfPods), and the necessary equipment (including construction suggestions), commonly employed to quantify sediments from algal turfs. We review the purposes of these methods (e.g. quantification of standing stock versus net accumulation) and how methods can vary depending on the research question or monitoring protocol. By providing these details in a readily accessible format we hope to encourage a standardised set of approaches for marine benthic ecologists, geologists and managers, that facilitates further quantification and global comparisons of algal turf sediments.
Many cameras make light work: opportunistic photographs of rare species in iNaturalist complement structured surveys of reef fish to better understand species richness
Publisher: Springer Science and Business Media LLC
Date: 03-2022
DOI: 10.1007/S10531-022-02398-6
Abstract: Citizen science is on the rise, with growing numbers of initiatives, participants and increasing interest from the broader scientific community. iNaturalist is an ex le of a successful citizen science platform that enables users to opportunistically capture and share bio ersity observations. Understanding how data from such opportunistic citizen science platforms compare with and complement data from structured surveys will improve their use in future bio ersity research. We compared the opportunistic fish photographs from iNaturalist to those obtained from structured surveys at eight study reefs in Sydney, Australia over twelve years. iNaturalist recorded 1.2 to 5.5 times more fish species than structured surveys resulting in significantly greater annual species richness at half of the reefs, with the remainder showing no significant difference. iNaturalist likely recorded more species due to having simple methods, which allowed for broad participation with substantially more iNaturalist observation events (e.g., es) than structured surveys over the same period. These results demonstrate the value of opportunistic citizen science platforms for documenting fish species richness, particularly where access and use of the marine environment is common and communities have the time and resources for expensive recreational activities (i.e., underwater photography). The datasets also recorded different species composition with iNaturalist recording many rare, less abundant, or cryptic species while the structured surveys captured many common and abundant species. These results suggest that integrating data from both opportunistic and structured data sources is likely to have the best outcome for future bio ersity monitoring and conservation activities.
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.
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.
Climate drives the geography of marine consumption by changing predator communities
Publisher: Proceedings of the National Academy of Sciences
Date: 26-10-2020
Abstract: Consumption transfers energy and materials through food chains and fundamentally influences ecosystem productivity. Therefore, mapping the distribution of consumer feeding intensity is key to understanding how environmental changes influence bio ersity, with consequent effects on trophic transfer and top–down impacts through food webs. Our global comparison of standardized bait consumption in shallow coastal habitats finds a peak in feeding intensity away from the equator that is better explained by the presence of particular consumer families than by latitude or temperature. This study complements recent demonstrations that changes in bio ersity can have similar or larger impacts on ecological processes than those of climate.
Genetic diversity in threatened Posidonia australis seagrass meadows
Publisher: Springer Science and Business Media LLC
Date: 28-01-2014
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.
Floating bags have the potential to minimise oyster farming impacts on Posidonia australis seagrass meadows
Publisher: Elsevier BV
Date: 11-2022
Seagrass Restoration Is Possible: Insights and Lessons From Australia and New Zealand
Publisher: Frontiers Media SA
Date: 14-08-2020
Positive and negative interactions control a facilitation cascade
Publisher: Wiley
Date: 12-2017
DOI: 10.1002/ECS2.2065
Persistence of seaweed forests in the anthropocene will depend on warming and marine heatwave profiles
Publisher: Wiley
Date: 22-12-2021
DOI: 10.1111/JPY.13222
Abstract: Marine heatwaves (MHWs), discrete periods of extreme warm water temperatures superimposed onto persistent ocean warming, have increased in frequency and significantly disrupted marine ecosystems. While field observations on the ecological consequences of MHWs are growing, a mechanistic understanding of their direct effects is rare. We conducted an outdoor tank experiment testing how different thermal stressor profiles impacted the ecophysiological performance of three dominant forest‐forming seaweeds. Four thermal scenarios were tested: contemporary summer temperature (22°C), low persistent warming (24°C), a discrete MHW (22–27°C), and temperature variability followed by a MHW (22–24°C, 22–27°C). The physiological performance of seaweeds was strongly related to thermal profile and varied among species, with the highest temperature not always having the strongest effect. MHWs were highly detrimental for the fucoid Phyllospora comosa , whereas the laminarian kelp Ecklonia radiata showed sensitivity to extended thermal stress and demonstrated a cumulative temperature threshold. The fucoid Sargassum linearifolium showed resilience, albeit with signs of decline with bleached and degraded fronds, under all conditions, with stronger decline under stable control and warming conditions. The varying responses of these three co‐occurring forest‐forming seaweeds under different temperature scenarios suggests that the impact of ocean warming on near shore ecosystems may be complex and will depend on the specific thermal profile of rising water temperatures relative to the vulnerability of different species.
Microbiome patterns across the gastrointestinal tract of the rabbitfish Siganus fuscescens
Publisher: PeerJ
Date: 17-05-2017
DOI: 10.7717/PEERJ.3317
Abstract: Most of our knowledge regarding the bio ersity of gut microbes comes from terrestrial organisms or marine species of economic value, with less emphasis on ecologically important species. Here we investigate the bacterial composition associated with the gut of Siganus fuscescens , a rabbitfish that plays an important ecological role in coastal ecosystems by consuming seaweeds. Members of Firmicutes, Bacteroidetes and delta-Proteobacteria were among the dominant taxa across s les taken from the contents and the walls (sites) of the midgut and hindgut (location). Despite the high variability among in idual fish, we observed statistically significant differences in beta- ersity between gut sites and gut locations. Some bacterial taxa low in abundance in the midgut content (e.g., Desulfovibrio ) were found in greater abundances on the midgut wall and within the hindgut, suggesting that the gut may select for specific groups of environmental and/or food-associated microorganisms. In contrast, some distinct taxa present in the midgut content (e.g., Synechococcus ) were noticeably reduced in the midgut wall and hindgut, and are thus likely to be representative of transient microbiota. This is the first assessment of the bacterial ersity associated with the gut of S. fuscescens and highlights the need to consider the variability across different gut locations and sites when analyzing fish gut microbiomes.
Financial and Institutional Support Are Important for Large-Scale Kelp Forest Restoration
Publisher: Frontiers Media SA
Date: 25-09-2020
Three Frontiers for the Future of Biodiversity Research Using Citizen Science Data
Publisher: Oxford University Press (OUP)
Date: 11-11-2020
Abstract: Citizen science is fundamentally shifting the future of bio ersity research. But although citizen science observations are contributing an increasingly large proportion of bio ersity data, they only feature in a relatively small percentage of research papers on bio ersity. We provide our perspective on three frontiers of citizen science research, areas that we feel to date have had minimal scientific exploration but that we believe deserve greater attention as they present substantial opportunities for the future of bio ersity research: s ling the unders led, capitalizing on citizen science's unique ability to s le poorly s led taxa and regions of the world, reducing taxonomic and spatial biases in global bio ersity data sets estimating abundance and density in space and time, develop techniques to derive taxon-specific densities from presence or absence and presence-only data and capitalizing on secondary data collection, moving beyond data on the occurrence of single species and gain further understanding of ecological interactions among species or habitats. The contribution of citizen science to understanding the important bio ersity questions of our time should be more fully realized.
Latitudinal patterns in trophic structure of temperate reef‐associated fishes and predicted consequences of climate change
Publisher: Wiley
Date: 21-07-2020
DOI: 10.1111/FAF.12488
Key Principles for Managing Recovery of Kelp Forests through Restoration
Publisher: Oxford University Press (OUP)
Date: 08-07-2020
Abstract: There is increasing interest in mitigating the loss of kelp forests through restoration, but this has received scant attention relative to other coastal habitats. We evaluate current knowledge centered on key restoration principles to provide guidelines for best practice in kelp restoration. The cause and scale of degradation is fundamental in determining if kelp can be restored and the methods required to promote reestablishment. Removal of stressors may be adequate to achieve restoration goals where degradation is not too widespread or acute. Extensive losses of kelp forests will often require active reseeding of areas because of the low dispersal ability of many kelp species. Restoration efforts have generally taken a trial-and-error approach at experimental scales to develop techniques for establishing in iduals. Furthermore, studies that inform cost–benefit analysis and the appropriate spatial scales for restoration of sustainable kelp forests are urgently needed for prioritizing and scaling up restoration efforts globally.
Combined mechanistic modelling predicts changes in species distribution and increased co‐occurrence of a tropical urchin herbivore and a habitat‐forming temperate kelp
Publisher: Wiley
Date: 13-06-2020
DOI: 10.1111/DDI.13073
The edible brown seaweed Alaria esculenta (Phaeophyceae, Laminariales): Hybridization, growth and genetic comparisons of six Irish populations
Publisher: Springer Science and Business Media LLC
Date: 2000
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
Natural and Regenerated Saltmarshes Exhibit Similar Soil and Belowground Organic Carbon Stocks, Root Production and Soil Respiration
Publisher: Springer Science and Business Media LLC
Date: 10-04-2019
The value of ecosystem services in global marine kelp forests
Publisher: Springer Science and Business Media LLC
Date: 18-04-2023
DOI: 10.1038/S41467-023-37385-0
Abstract: While marine kelp forests have provided valuable ecosystem services for millennia, the global ecological and economic value of those services is largely unresolved. Kelp forests are diminishing in many regions worldwide, and efforts to manage these ecosystems are hindered without accurate estimates of the value of the services that kelp forests provide to human societies. Here, we present a global estimate of the ecological and economic potential of three key ecosystem services - fisheries production, nutrient cycling, and carbon removal provided by six major forest forming kelp genera ( Ecklonia, Laminaria, Lessonia, Macrocystis, Nereocystis , and Saccharina ). Each of these genera creates a potential value of between $64,400 and $147,100/hectare each year. Collectively, they generate between $465 and $562 billion/year worldwide, with an average of $500 billion. These values are primarily driven by fisheries production (mean $29,900, 904 Kg/Ha/year) and nitrogen removal ($73,800, 657 Kg N/Ha/year), though kelp forests are also estimated to sequester 4.91 megatons of carbon from the atmosphere/year highlighting their potential as blue carbon systems for climate change mitigation. These findings highlight the ecological and economic value of kelp forests to society and will facilitate better informed marine management and conservation decisions.
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.
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.
Compensation and resistance to herbivory in seagrasses: induced responses to simulated consumption by fish
Publisher: Springer Science and Business Media LLC
Date: 10-01-2008
DOI: 10.1007/S00442-007-0943-4
Abstract: Herbivory can induce changes in plant traits that may involve both tolerance mechanisms that compensate for biomass loss and resistance traits that reduce herbivore preference. Seagrasses are marine vascular plants that possess many attributes that may favour tolerance and compensatory growth, and they are also defended with mechanisms of resistance such as toughness and secondary metabolites. We quantified phenotypic changes induced by herbivore damage on the temperate seagrass Posidonia oceanica in order to identify specific compensatory and resistance mechanisms in this plant, and to assess any potential trade-offs between these two strategies of defence. We simulated three natural levels of fish herbivory by repeatedly clipping seagrass leaves during the summer period of maximum herbivory. Compensatory responses were determined by measuring shoot-specific growth, photosynthetic rate, and the concentration of nitrogen and carbon resources in leaves and rhizomes. Induced resistance was determined by measuring the concentration of phenolic secondary metabolites and by assessing the long-term effects of continued clipping on herbivore feeding preferences using bioassays. Plants showed a significant ability to compensate for low and moderate losses of leaf biomass by increasing aboveground growth of damaged shoots, but this was not supported by an increase in photosynthetic capacity. Low levels of herbivory induced compensatory growth without any measurable effects on stored resources. In contrast, nitrogen reserves in the rhizomes played a crucial role in the plant's ability to compensate and survive herbivore damage under moderate and high levels of herbivory, respectively. We found no evidence of inducibility of long-term resistance traits in response to herbivory. The concentration of phenolics decreased with increasing compensatory growth despite all treatments having similar carbon leaf content, suggesting reallocation of these compounds towards primary functions such as cell-wall construction.
Herbivores strongly influence algal recruitment in both coral- and algal-dominated coral reef habitats
Publisher: Inter-Research Science Center
Date: 12-07-2013
DOI: 10.3354/MEPS10325
Selection of multiple seagrass indicators for environmental biomonitoring
Publisher: Inter-Research Science Center
Date: 09-06-2008
DOI: 10.3354/MEPS07358
Spatial patterns in herbivory on a coral reef are influenced by structural complexity but not by algal traits
Publisher: Public Library of Science (PLoS)
Date: 11-02-2011
Persistent thermally driven shift in the functional trait structure of herbivorous fishes: Evidence of top‐down control on the rebound potential of temperate seaweed forests?
Publisher: Wiley
Date: 14-01-2022
DOI: 10.1111/GCB.16070
Abstract: Extreme climatic events can reshape the functional structure of ecological communities, potentially altering ecological interactions and ecosystem functioning. While these shifts have been widely documented, evidence of their persistence and potential flow‐on effects on ecosystem structure following relaxation of extreme events remains limited. Here, we investigate changes in the functional trait structure – encompassing dimensions of resource use, thermal affinity, and body size – of herbivorous fishes in a temperate reef system that experienced an extreme marine heatwave (MHW) and subsequent return to cool conditions. We quantify how changes in the trait structure modified the nature and intensity of herbivory‐related functions (macroalgae, turf, and sediment removal), and explored the potential flow‐on effects on the recovery dynamics of macroalgal foundation species. The trait structure of the herbivorous fish assemblage shifted as a result of the MHW, from dominance of cool‐water browsing species to increased evenness in the distribution of abundance among temperate and tropical guilds supporting novel herbivory roles (i.e. scraping, cropping, and sediment sucking). Despite the abundance of tropical herbivorous fishes and intensity of herbivory‐related functions declined following a period of cooling after the MHW, the underlying trait structure displayed limited recovery. Concomitantly, algal assemblages displayed a lack of recovery of the formerly dominant foundational species, the kelp Ecklonia radiata , transitioning to an alternative state dominated by turf and Sargassum spp. Our study demonstrates a legacy effect of an extreme MHW and exemplified the value of monitoring phenotypic (trait mediated) changes in the nature of core ecosystem processes to predict and adapt to the future configurations of changing reef ecosystems.
Differences in predator composition alter the direction of structure‐mediated predation risk in macrophyte communities
Publisher: Wiley
Date: 29-04-2014
DOI: 10.1111/OIK.01382
Future changes to the upper ocean Western Boundary Currents across two generations of climate models
Publisher: Springer Science and Business Media LLC
Date: 05-05-2021
DOI: 10.1038/S41598-021-88934-W
Abstract: Western Boundary Currents (WBCs) are important for the oceanic transport of heat, dissolved gases and nutrients. They can affect regional climate and strongly influence the dispersion and distribution of marine species. Using state-of-the-art climate models from the latest and previous Climate Model Intercomparison Projects , we evaluate upper ocean circulation and examine future projections, focusing on subtropical and low-latitude WBCs. Despite their coarse resolution, climate models successfully reproduce most large-scale circulation features with ensemble mean transports typically within the range of observational uncertainty, although there is often a large spread across the models and some currents are systematically too strong or weak. Despite considerable differences in model structure, resolution and parameterisations, many currents show highly consistent projected changes across the models. For ex le, the East Australian Current, Brazil Current and Agulhas Current extensions are projected to intensify, while the Gulf Stream, Indonesian Throughflow and Agulhas Current are projected to weaken. Intermodel differences in most future circulation changes can be explained in part by projected changes in the large-scale surface winds. In moving to the latest model generation, despite structural model advancements, we find little systematic improvement in the simulation of ocean transports nor major differences in the projected changes.
Author Correction: The value of ecosystem services in global marine kelp forests
Publisher: Springer Science and Business Media LLC
Date: 18-05-2023
The need, opportunities, and challenges for creating a standardized framework for marine restoration monitoring and reporting
Publisher: Elsevier BV
Date: 02-2022
Naturally-detached fragments of the endangered seagrass Posidonia australis collected by citizen scientists can be used to successfully restore fragmented meadows
Publisher: Elsevier BV
Date: 10-2021
Tropical rabbitfish and the deforestation of a warming temperate sea
Publisher: Wiley
Date: 23-09-2014
Episodic and non-uniform shifts of thermal habitats in a warming ocean
Publisher: Elsevier BV
Date: 03-3000
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