ORCID Profile
0000-0001-8038-2771
Current Organisation
CSIRO
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Environmental Science and Management | Conservation and Biodiversity | Natural Resource Management | Wildlife and Habitat Management | Invasive Species Ecology
Sparseland, Permanent Grassland and Arid Zone Flora, Fauna and Biodiversity | Ecosystem Assessment and Management of Coastal and Estuarine Environments | Marine Flora, Fauna and Biodiversity | Control of Pests, Diseases and Exotic Species in Sparseland, Permanent Grassland and Arid Zone Environments | Ecosystem Assessment and Management of Marine Environments |
Publisher: Public Library of Science (PLoS)
Date: 06-12-2022
DOI: 10.1371/JOURNAL.PBIO.3001907
Abstract: Quantifying patterns of dispersal and settlement in marine benthic invertebrates is challenging, largely due the complexity of life history traits, small sizes of larvae ( mm), and potential for large-scale dispersal ( km) in the marine environment. Here, we develop a novel method that allows for immediate differentiation and visual tracking of large numbers of coral larvae (10 6 to 10 9 ) from dispersal to settlement. Neutral red and Nile blue stains were extremely effective in coloring larvae, with minimal impacts on survival and settlement following optimization of incubation times and stain concentrations. Field validation to wild-captured larvae from the Great Barrier Reef demonstrates the efficacy of staining across erse taxa. The method provides a simple, rapid ( minutes), low-cost (approximately USD$1 per 10 5 larva) tool to color coral larvae that facilitates a wide range of de novo laboratory and field studies of larval behavior and ecology with potential applications for conservation planning and understanding patterns of connectivity.
Publisher: Wiley
Date: 25-07-2023
Abstract: Larval settlement and recruitment of sessile organisms are key ecological processes for population recovery and maintenance that occur at scales invisible to the human eye. Accordingly, proxies of recruitment have commonly been quantified using artificial substrata such as settlement tiles made of erse materials and shapes, which are typically transported to the laboratory for examination. However, it is unknown how much bias is introduced with this s ling strategy and how recruitment quantified on tiles relates to recruitment on nearby natural substrata. Here, we applied techniques that combine macrophotography with photogrammetry (macrophotogrammetry) underwater to monitor benthic communities at submillimetre scale. This application allows the investigation of recruitment and community succession of the earliest life‐history stages in situ and on natural substrata. We tested the use of four different imaging systems, varying in costs from US$ 1400 to US$ 5440. While the most expensive SONY αRiv system provided the best visual output and ground resolution (up to 5 μm ixel with a + 4 close‐up lens) regardless of systems, 3D models always had a ground resolution ≤23 μm ixel and errors in planar measurements of submillimetre features were similar among systems. This level of resolution compares well with stereomicroscopy in the range of 5:1 to 10:1 magnification, while providing detailed 3D digital records through time. Using a coral reef ex le, we apply this approach to demonstrate how it can be used to monitor small reef areas (~300–600 cm 2 ) through time, including the quantification of biophysical metrics such as cover of small facilitative and competitive organisms and microhabitat complexity. We further show that organisms as small 0.5 mm in size, such as 2‐month‐old coral settlers, can be located accurately within the 3D models and measured with a good level of confidence. This method can be readily applied to other benthic environments to elucidate drivers of early recruitment and recovery of benthic organisms following disturbance impacts at very fine scales, directly on natural substrata, to avoid biases inherent with laboratory‐based analyses of artificial surfaces.
Publisher: Springer Science and Business Media LLC
Date: 10-11-2014
DOI: 10.1038/NCLIMATE2439
Publisher: Frontiers Media SA
Date: 25-10-2019
Publisher: Springer Science and Business Media LLC
Date: 16-11-2017
Publisher: Copernicus GmbH
Date: 24-10-2023
Publisher: Inter-Research Science Center
Date: 20-01-2012
DOI: 10.3354/MEPS09367
Publisher: Wiley
Date: 07-11-2018
DOI: 10.1002/ECM.1336
Publisher: Inter-Research Science Center
Date: 26-11-2015
DOI: 10.3354/MEPS11518
Publisher: University of Chicago Press
Date: 06-2014
Publisher: Wiley
Date: 02-2017
DOI: 10.1002/ECY.1663
Abstract: Community succession following disturbance depends on positive and negative interactions, the strength of which change along environmental gradients. To investigate how early succession affects coral reef recovery, we conducted an 18-month experiment in Palau, using recruitment tiles and herbivore exclusion cages. One set of reefs has higher wave exposure and had previously undergone a phase shift to macroalgae following a major typhoon, whereas the other set of reefs have lower wave exposure and did not undergo a macroalgal phase shift. Similar successional trajectories were observed at all sites when herbivores were excluded: turf algae dominated early succession, followed by shifts to foliose macroalgae and heterotrophic invertebrates. However, trajectories differed in the presence of herbivores. At low wave exposure reefs, herbivores promoted coralline algae and limited turf and encrusting fleshy algae in crevice microhabitats, facilitating optimal coral recruitment. Under medium wave exposure, relatively higher but still low coverage of turf and encrusting fleshy algae (15-25%) found in crevice microhabitats inhibited coral recruitment, persisting throughout multiple recruitment events. Our results indicate that altered interaction strength in different wave environments following disturbance can drive subtle changes in early succession that cascade to alter secondary succession to coral recruitment and system recovery.
Publisher: Wiley
Date: 09-02-2012
DOI: 10.1111/J.1461-0248.2012.01743.X
Abstract: Ecology Letters (2012) 15: 338-346 ABSTRACT: Successful recruitment in shallow reef ecosystems often involves specific cues that connect planktonic invertebrate larvae with particular crustose coralline algae (CCA) during settlement. While ocean acidification (OA) can reduce larval settlement and the abundance of CCA, the impact of OA on the interactions between planktonic larvae and their preferred settlement substrate are unknown. Here, we demonstrate that CO2 concentrations (800 and 1300 μatm) predicted to occur by the end of this century significantly reduce coral (Acropora millepora) settlement and CCA cover by ≥ 45%. The CCA important for inducing coral settlement (Titanoderma spp., Hydrolithon spp.) were the most deleteriously affected by OA. Surprisingly, the only preferred settlement substrate (Titanoderma) in the experimental controls was avoided by coral larvae as pCO2 increased, and other substrata selected. Our results suggest OA may reduce coral population recovery by reducing coral settlement rates, disrupting larval settlement behaviour, and reducing the availability of the most desirable coralline algal species for successful coral recruitment.
Publisher: Wiley
Date: 13-03-2022
DOI: 10.1002/EAP.2558
Abstract: Positive feedbacks driving habitat‐forming species recovery and population growth are often lost as ecosystems degrade. For such systems, identifying mechanisms that limit the re‐establishment of critical positive feedbacks is key to facilitating recovery. Theory predicts the primary drivers limiting system recovery shift from biological to physical as abiotic stress increases, but recent work has demonstrated that this seldom happens. We combined field and laboratory experiments to identify variation in limitations to coral recovery along an environmental stress gradient at Ningaloo Reef and Exmouth Gulf in northwest Australia. Many reefs in the region are coral depauperate due to recent cyclones and thermal stress. In general, recovery trajectories are prolonged due to limited coral recruitment. Consistent with theory, clearer water reefs under low thermal stress appear limited by biological interactions: competition with turf algae caused high mortality of newly settled corals and upright macroalgal stands drove mortality in transplanted juvenile corals. Laboratory experiments showed a positive relationship between crustose coralline algae cover and coral settlement, but only in the absence of sedimentation. Contrary to expectation, coral recovery does not appear limited by the survival or growth of recruits on turbid reefs under higher thermal stress, but to exceptionally low larval supply. Laboratory experiments showed that larval survival and settlement are unaffected by seawater quality across the study region. Rather, connectivity models predicted that many of the more turbid reefs in the Gulf are predominantly self seeded, receiving limited supply under degraded reef states. Overall, we find that the influence of oceanography can overwhelm the influences of physical and biological interactions on recovery potential at locations where environmental stressors are high, whereas populations in relatively benign physical conditions are predominantly structured by local ecological drivers. Such context‐dependent information can help guide expectations and assist managers in optimizing strategies for spatial conservation planning for system recovery.
Publisher: Springer Science and Business Media LLC
Date: 20-06-2018
Publisher: Oxford University Press (OUP)
Date: 19-06-2020
Abstract: We introduce five measures describing the system-wide behaviour of complex ecological systems. Within an information-theoretic framework, these measures account for changes in both species ersity and total biomass to describe (i) overall system change, (ii) sustainability to external pressure, (iii) shift from a baseline state and two types of resilience: (iv) ability to recover from local pressures and (v) overall potential to return to a baseline state. We apply these measures to study the behaviour of three computer models: a large 59-functional groups complex ecological model (Ecopath with Ecosim) of north Western Australia undergoing internal dynamics, a smaller 6-group coral reef model subjected to various combinations of single and multiple stressors and a prey–predator model displaying limit cycles. We demonstrate the state-dependency of properties like resilience and sustainability by showing how these measures change in time as a function of internal dynamics and external forcing. Furthermore, we show how our proposed measures can simplify system analysis and monitoring by providing indicators of changes in system behaviour, sustainability, and resilience.
Publisher: Copernicus GmbH
Date: 16-02-2023
DOI: 10.5194/BG-2023-2
Abstract: Abstract. The proportional cover of rubble on reefs is predicted to increase as disturbances increase in intensity and frequency. Unstable rubble can kill coral recruits and impair binding processes that consolidate rubble into a stable substrate for coral recruitment. A clearer understanding of the mechanisms of inhibited coral recovery on rubble requires characterisation of the hydrodynamic conditions that trigger rubble mobilisation. Here, we investigated rubble mobilisation under regular wave conditions in a wave flume and irregular wave conditions in-situ on a coral reef in the Mal es. We examined how changes in near-bed wave orbital velocity influenced the likelihood of rubble motion (e.g., rocking) and transport (by walking, sliding or flipping). Rubble mobilisation was considered as a function of rubble length, branchiness (branched vs. unbranched), and underlying substrate (rubble vs. sand). Rubble was more likely to be transported if ieces were small (4–8 cm) and had no branches, and rubble travelled slightly greater distances (~2 cm) per day on substrates composed of sand than rubble. The effect of near-bed wave orbital velocity on rubble mobilisation was comparable between flume and reef observations. Rubble had a 50 % and 90 % chance of transport when near-bed wave orbital velocities reached 0.30 m/s and 0.43 m/s, respectively, in the wave flume, and 0.34 m/s and 0.55 m/s, respectively, on the reef. Importantly, the probability of rubble transport per day declined over 3-day deployments in the field, suggesting rubble had settled into more hydrodynamically-stable positions or snagged on the first day of deployment. We expect that settled or snagged rubble may have been mobilised more commonly in locations with higher energy and more variable wave environments. Our results show that rubble beds comprised of small rubble pieces and/or pieces with fewer branches are likely to be more unstable. Such rubble beds are likely to have shorter windows of recovery (stability) between mobilisation events, and thus be good candidates for rubble stabilisation interventions to enhance coral recruitment and binding.
Publisher: Springer Science and Business Media LLC
Date: 08-04-2020
Publisher: Wiley
Date: 31-08-2018
DOI: 10.1111/GEB.12767
Publisher: Wiley
Date: 02-07-2023
Abstract: Humans have long sought to restore species but little attention has been directed at how to best select a subset of foundation species for maintaining rich assemblages that support ecosystems, like coral reefs and rainforests, which are increasingly threatened by environmental change. We propose a two‐part hedging approach that selects optimized sets of species for restoration. The first part acknowledges that bio ersity supports ecosystem functions and services, and so it ensures precaution against loss by allocating an even spread of phenotypic traits. The second part maximizes species and ecosystem persistence by weighting species based on characteristics that are known to improve ecological persistence—for ex le abundance, species range and tolerance to environmental change. Using existing phenotypic‐trait and ecological data for reef building corals, we identified sets of ecologically persistent species by examining marginal returns in occupancy of phenotypic trait space. We compared optimal sets of species with those from the world's southern‐most coral reef, which naturally harbours low coral ersity, to show these occupy much of the trait space. Comparison with an existing coral restoration program indicated that current corals used for restoration only cover part of the desired trait space and programs may be improved by including species with different traits. Synthesis and applications . While there are many possible criteria for selecting species for restoration, the approach proposed here addresses the need to insure against unpredictable losses of ecosystem services by focusing on a wide range of phenotypic traits and ecological characteristics. Furthermore, the flexibility of the approach enables the functional goals of restoration to vary depending on environmental context, stakeholder values, and the spatial and temporal scales at which meaningful impacts can be achieved.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 15-05-2015
Publisher: Inter-Research Science Center
Date: 04-03-2021
DOI: 10.3354/MEPS13608
Abstract: It is hypothesized that spatio-temporal variability in larval supply is caused by multiple biophysical drivers which correlate with the occurrence of recruitment pulses, influencing the recovery potential of coral reefs following large-scale disturbances. Here, we used a larval dispersal model to explore coral larvae dispersal patterns under variable oceanographic conditions, densities of parental colonies, and taxon-specific biology of propagules. Model predictions were validated with observed settlement and recruitment data to test the robustness of larval dispersal modelling for forecasting the recovery potential of study reefs. The model was applied to the western Pacific archipelago of Palau for 3 yr before and after major typhoon disturbances, and simulations were run and validated for 2 major broadcast-spawning reef-building taxa: Acropora and Porites. Investigations into the relative role of physical (currents, wind, waves) and biological (taxa, disturbance impact) parameters on overall larval supply show that low wind speeds and the intermittent occurrence of north and southwest oceanic currents contributed significantly to enhancing larval supply at the scale of the archipelago. Reduced parental colony densities on eastern reefs following disturbances did not have a major impact on predicted larval supply patterns. Relatively low larval supply to most of the disturbed eastern reefs is predicted during the most common oceanographic conditions, forecasting low recovery potential through larval recruitment. Mapping the spatio-temporal dynamics of larval supply and identifying barriers to dispersal from intact to disturbed reefs can help predict recovery patterns across reef communities.
Publisher: IOP Publishing
Date: 07-2016
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.
Publisher: Springer Science and Business Media LLC
Date: 13-09-2018
Publisher: Elsevier BV
Date: 06-2009
Publisher: Springer Science and Business Media LLC
Date: 17-10-2018
Publisher: Wiley
Date: 22-01-2019
DOI: 10.1111/REC.12918
Publisher: Elsevier BV
Date: 10-2021
Publisher: Springer Science and Business Media LLC
Date: 13-03-2015
DOI: 10.1007/S00442-015-3282-X
Abstract: While positive interactions have been observed to influence patterns of recruitment and succession in marine and terrestrial plant communities, the role of facilitation in macroalgal phase shifts is relatively unknown. In December 2012, typhoon Bopha caused catastrophic losses of corals on the eastern reefs of Palau. Within weeks of the typhoon, an ephemeral bloom of monospecific macroalgae (Liagora sp.) was observed, reaching a peak of 38.6% cover in February 2013. At this peak, we observed a proliferation of a second macroalgal species, Lobophora variegata. Lobophora was distributed non-randomly, with higher abundances occurring within the shelter of Liagora canopies than on exposed substrates. Bite rates of two common herbivorous fish (Chlorurus sordidus and Ctenochaetus striatus) were significantly higher outside canopies (2.5- and sixfold, respectively), and cage exclusion resulted in a significant increase in Lobophora cover. Experimental removal of Liagora canopies resulted in a 53.1% decline in the surface area of Lobophora after 12 days, compared to a 51.7% increase within canopies. Collectively, these results indicate that Liagora canopies act as ecological facilitators, providing a 'nursery' exclusion zone from the impact of herbivorous fish, allowing for the establishment of understory Lobophora. While the ephemeral Liagora bloom had disappeared entirely 9 months post-typhoon, the facilitated shift to Lobophora has persisted for over 18 months, dominating ~40% of the reef substrate. While acute disturbance events such as typhoons have been suggested as a mechanism to reverse algal phase shifts, our results suggest that typhoons may also trigger, rather than just reverse, phase shifts.
Publisher: Wiley
Date: 18-10-2021
DOI: 10.1002/ECY.3536
Abstract: Herbivory and nutrient availability are fundamental drivers of benthic community succession in shallow marine systems, including coral reefs. Despite the importance of early community succession for coral recruitment and recovery, studies characterizing the impact of top‐down and bottom‐up drivers on micro‐ and macrobenthic communities at scales relevant to coral recruitment are lacking. Here, a combination of tank and field experiments were used to assess the effects of herbivore exclusion and nutrient enrichment on micro‐ to macrobenthic community succession and subsequent coral recruitment success. Herbivore exclusion had the strongest effect on micro‐ and macrobenthic community succession, including a community shift toward copiotrophic and potentially opportunistic athogenic microorganisms, an increased cover of turf and macroalgae, and decreased cover of crustose coralline algae. Yet, when corals settled prior to the development of a macrobenthic community, rates of post‐settlement survival increased when herbivores were excluded, benefiting from the predation refugia provided by cages during their vulnerable early post‐settlement stage. Interestingly, survival on open tiles was negatively correlated with the relative abundance of the bacterial order Rhodobacterales , an opportunistic microbial group previously associated with stressed and diseased corals. Development of micro‐ and macrobenthic communities in the absence of herbivory, however, led to reduced coral settlement. In turn, there were no differences in post‐settlement survival between open and caged treatments for corals settled on tiles with established benthic communities. As a result, open tiles experienced marginally higher recruitment rates, driven primarily by the higher initial number of settlers on open tiles compared to caged tiles. Overall, we reveal that the primary interaction driving coral recruitment is the positive effect of herbivory in creating crustose coralline algae (CCA)‐dominated habitats, free of fleshy algae and associated opportunistic microbes, to enhance coral settlement. The negative direct and indirect impact of fish predation on newly settled corals was outweighed by the positive effect of herbivory on the initial rate of coral settlement. In turn, the addition of nutrients further altered benthic community succession in the absence of herbivory, reducing coral post‐settlement survival. However, the overall impact of nutrients on coral recruitment dynamics was minor relative to herbivory.
Publisher: The Royal Society
Date: 20-02-2019
Abstract: Understanding processes that drive community recovery are needed to predict ecosystem trajectories and manage for impacts under increasing global threats. Yet, the quantification of community recovery in coral reefs has been challenging owing to a paucity of long-term ecological data and high frequency of disturbances. Here we investigate community re-assembly and the bio-physical drivers that determine the capacity of coral reefs to recover following the 1998 bleaching event, using long-term monitoring data across four habitats in Palau. Our study documents that the time needed for coral reefs to recover from bleaching disturbance to coral-dominated state in disturbance-free regimes is at least 9–12 years. Importantly, we show that reefs in two habitats achieve relative stability to a climax community state within that time frame. We then investigated the direct and indirect effects of drivers on the rate of recovery of four dominant coral groups using a structural equation modelling approach. While the rates of recovery differed among coral groups, we found that larval connectivity and juvenile coral density were prominent drivers of recovery for fast growing Acropora but not for the other three groups. Competitive algae and parrotfish had negative and positive effects on coral recovery in general, whereas wave exposure had variable effects related to coral morphology. Overall, the time needed for community re-assembly is habitat specific and drivers of recovery are taxa specific, considerations that require incorporation into planning for ecosystem management under climate change.
Publisher: Springer Science and Business Media LLC
Date: 13-04-2014
Publisher: MDPI AG
Date: 06-12-2021
Abstract: Bolbometopon muricatum (bumphead parrotfish, Valenciennes, 1839) is a conspicuous, iconic and ecologically important coral reef fish species. B. muricatum plays an important role in the bioerosion of the reef framework and as a result has been described as both an ecosystem engineer and keystone species. Despite the complete absence of B. muricatum from 32 years of scientific surveys across the Ningaloo Reef World Heritage Area, we recorded a total of 155 in iduals of B. muricatum across 63.2 ha of reef crest surveys, equating to mean density of 2.38 ind/ha. Our observations represent the first record of this iconic species in scientific surveys at Ningaloo and in combination with qualitative observations of B. muricatum by expert witnesses, indicate B. muricatum is likely to have been present in ecologically relevant densities since 2006. The densities of B. muricatum observed at northern Ningaloo in 2021 suggest this species is removing an estimated 13.42 tonnes/ha or 1.34 kg/m2 of calcium carbonate per year, which is broadly comparable with estimates of total parrotfish bioerosion across many reefs in the central Indian and Pacific Oceans. Although not currently afforded elevated conservation status within management plans, B. muricatum possess many life-history characteristics that make them vulnerable to overfishing and may justify consideration for increased protection within the world heritage listed Ningaloo Reef Marine Park.
Publisher: No publisher found
Date: 2015
DOI: 10.5061/DRYAD.RJ653
Publisher: Springer Science and Business Media LLC
Date: 29-01-2021
DOI: 10.1038/S41597-020-00793-8
Abstract: The discovery of multi-species synchronous spawning of scleractinian corals on the Great Barrier Reef in the 1980s stimulated an extraordinary effort to document spawning times in other parts of the globe. Unfortunately, most of these data remain unpublished which limits our understanding of regional and global reproductive patterns. The Coral Spawning Database (CSD) collates much of these disparate data into a single place. The CSD includes 6178 observations (3085 of which were unpublished) of the time or day of spawning for over 300 scleractinian species in 61 genera from 101 sites in the Indo-Pacific. The goal of the CSD is to provide open access to coral spawning data to accelerate our understanding of coral reproductive biology and to provide a baseline against which to evaluate any future changes in reproductive phenology.
Publisher: Springer Science and Business Media LLC
Date: 08-2019
DOI: 10.1038/S41467-019-11367-7
Abstract: Many habitat-building corals undergo mass synchronous spawning events. Yet, despite the enormous amounts of larvae produced, larval dispersal from a single spawning event and the reliability of larval supply are highly dependent on vagaries of ocean currents. However, colonies from the same population will occasionally spawn over successive months. These split spawning events likely help to realign reproduction events to favourable environmental conditions. Here, we show that split spawning may benefit corals by increasing the reliability of larval supply. By modelling the dispersal of coral larvae across Australia’s Great Barrier Reef, we find that split spawning increased the ersity of sources and reliability of larval supply the reefs could receive, especially in regions with low and intrinsically variable connectivity. Such increased larval supply might help counteract the expected declines in reproductive success associated with split spawning events.
Publisher: Inter-Research Science Center
Date: 07-03-2019
DOI: 10.3354/MEPS12879
Publisher: Springer Science and Business Media LLC
Date: 28-10-2023
Publisher: Wiley
Date: 10-2012
DOI: 10.1890/12-0495.1
Abstract: Newly settled recruits typically suffer high mortality from disturbances, but rapid growth reduces their mortality once size-escape thresholds are attained. Ocean acidification (OA) reduces the growth of recruiting benthic invertebrates, yet no direct effects on survivorship have been demonstrated. We tested whether the reduced growth of coral recruits caused by OA would increase their mortality by prolonging their vulnerability to an acute disturbance: fish herbivory on surrounding algal turf. After two months' growth in ambient or elevated CO2 levels, the linear extension and calcification of coral (Acropora millepora) recruits decreased as CO2 partial pressure (pCO2) increased. When recruits were subjected to incidental fish grazing, their mortality was inversely size dependent. However, we also found an additive effect of pCO2 such that recruit mortality was higher under elevated pCO2 irrespective of size. Compared to ambient conditions, coral recruits needed to double their size at the highest pCO2 to escape incidental grazing mortality. This general trend was observed with three groups of predators (blenny, surgeonfish, and parrotfish), although the magnitude of the fish treatment varied among species. Our study demonstrates the importance of size-escape thresholds in early recruit survival and how OA can shift these thresholds, potentially intensifying population bottlenecks in benthic invertebrate recruitment.
Publisher: CRC Press
Date: 22-09-2021
Publisher: The Royal Society
Date: 07-11-2018
Abstract: Understanding the dynamics of habitat-forming organisms is fundamental to managing natural ecosystems. Most studies of coral reef dynamics have focused on clear-water systems though corals inhabit many turbid regions. Here, we illustrate the key drivers of an inshore coral reef ecosystem using 10 years of biological, environmental, and disturbance data. Tropical cyclones, crown-of-thorns starfish, and coral bleaching are recognized as the major drivers of coral loss at mid- and offshore reefs along the Great Barrier Reef (GBR). In comparison, little is known about what drives temporal trends at inshore reefs closer to major anthropogenic stress. We assessed coral cover dynamics using state-space models within six major inshore GBR catchments. An overall decline was detected in nearly half (46%) of the 15 reefs at two depths (30 sites), while the rest exhibited fluctuating (23%), static (17%), or positive (13%) trends. Inshore reefs responded similarly to their offshore counterparts, where contemporary trends were predominantly influenced by acute disturbance events. Storms emerged as the major driver affecting the inshore GBR, with the effects of other drivers such as disease, juvenile coral density, and macroalgal and turf per cent cover varying from one catchment to another. Flooding was also associated with negative trends in live coral cover in two southern catchments, but the mechanism remains unclear as it is not reflected in available metrics of water quality and may act through indirect pathways.
Publisher: Wiley
Date: 25-05-2017
DOI: 10.1111/JFB.13340
Abstract: The present study reports a previously undocumented mass spawning aggregation and group spawning phenomena of c. 1200 in idual bumphead parrotfish Bolbometopon muricatum in Palau, Micronesia. Although B. muricatum are protected in Palau, it is further recommended that management strategies should consider establishment of no-take zones at B. muricatum spawning aggregations and concomitant sleeping grounds elsewhere.
Publisher: Wiley
Date: 07-11-2020
DOI: 10.1002/EAP.2011
Abstract: Population persistence in the marine environment is driven by patterns of ocean circulation, larval dispersal, ecological interactions, and demographic rates. For habitat-forming organisms in particular, understanding the relationship between larval connectivity and meta-population dynamics aids in planning for marine spatial management. Here, we estimate networks of connectivity between fringing coral reefs in the northwest shelf of Australia by combining a particle tracking model based on shelf circulation with models of subpopulation dynamics of in idual reefs. Coral cover data were used as a proxy for overall habitat quality, which can change as a result of natural processes, human-driven impacts, and management initiatives. We obtain three major results of conservation significance. First, the dynamics of the ecological network result from the interplay between network connectivity and ecological processes on in idual reefs. The maximum coral cover a zone can sustain imposes a significant nonlinearity on the role an in idual reef plays within the dynamics of the network, and thus on the impact of conservation interventions on specific reefs. Second, the role of an in idual reef within these network dynamics changes considerably depending on the overall state of the system: a reef's role in sustaining the system's state can be different from the same reef's role in helping the system recover following major disturbance. Third, patterns of network connectivity change significantly as a function of yearly shelf circulation trends, and nonlinearity in network dynamics make mean connectivity a poor representation of yearly variations. From a management perspective, the priority list of reefs that are targets for management interventions depends crucially on what type of stressors (system-wide vs. localized) need addressing. This choice also depends not only on the ultimate purpose of management, but also on future oceanographic, climate change, and development scenarios that will determine the network connectivity and habitat quality.
Publisher: The Royal Society
Date: 05-2017
DOI: 10.1098/RSOS.170082
Abstract: Population growth involves demographic bottlenecks that regulate recruitment success during various early life-history stages. The success of each early life-history stage can vary in response to population density, interacting with intrinsic (e.g. behavioural) and environmental (e.g. competition, predation) factors. Here, we used the common reef-building coral Acropora millepora to investigate how density-dependence influences larval survival and settlement in laboratory experiments that isolated intrinsic effects, and post-settlement survival in a field experiment that examined interactions with environmental factors. Larval survival was exceptionally high (greater than 80%) and density-independent from 2.5 to 12 days following spawning. By contrast, there was a weak positive effect of larval density on settlement, driven by gregarious behaviour at the highest density. When larval supply was saturated, settlement was three times higher in crevices compared with exposed microhabitats, but a negative relationship between settler density and post-settlement survival in crevices and density-independent survival on exposed surfaces resulted in similar recruit densities just one month following settlement. Moreover, a negative relationship was found between turf algae and settler survival in crevices, whereas gregarious settlement improved settler survival on exposed surfaces. Overall, our findings reveal ergent responses by coral larvae and newly settled recruits to density-dependent regulation, mediated by intrinsic and environmental interactions.
Publisher: Public Library of Science (PLoS)
Date: 10-02-2017
Publisher: Springer Science and Business Media LLC
Date: 25-05-2020
Publisher: Wiley
Date: 11-02-2022
DOI: 10.1002/ECY.3621
Publisher: Inter-Research Science Center
Date: 14-02-2013
DOI: 10.3354/MEPS10096
Publisher: Springer Science and Business Media LLC
Date: 21-05-2018
DOI: 10.1038/S41559-018-0563-X
Abstract: The United Nations 2030 Agenda for Sustainable Development calls for urgent actions to reduce global bio ersity loss. Here, we synthesize >44,000 articles published in the past decade to assess the research focus on global drivers of loss. Relative research efforts on different drivers are not well aligned with their assessed impact, and multiple driver interactions are hardly considered. Research on drivers of bio ersity loss needs urgent realignment to match predicted severity and inform policy goals.
Publisher: Springer Science and Business Media LLC
Date: 12-02-2020
DOI: 10.1038/S41598-020-59111-2
Abstract: Following disturbances, corals recolonize space through the process of recruitment consisting of the three phases of propagule supply, settlement, and post-settlement survival. Yet, each phase is influenced by biophysical factors, leading to recruitment success variability through space. To resolve the relative contributions of biophysical factors on coral recruitment, the recovery of a 150 km long coral reefs in Palau was investigated after severe typhoon disturbances. Overall, we found that benthic organisms had a relatively weak interactive influence on larval settlement rates at the scale of in idual tiles, with negative effects mainly exerted from high wave exposure for Acropora corals. In contrast, juvenile coral densities were well predicted by biophysical drivers, through both direct and indirect pathways. High densities of Acropora and Poritidae juveniles were directly explained by the availability of substrata free from space competitors. Juvenile Montipora were found in higher densities where coralline algae coverage was high, which occurred at reefs with high wave exposure, while high densities of juvenile Pocilloporidae occurred on structurally complex reefs with high biomass of bioeroder fish. Our findings demonstrate that strengths of biophysical interactions were taxon-specific and had cascading effects on coral recruitment, which need consideration for predicting reef recovery and conservation strategies.
Publisher: Springer Science and Business Media LLC
Date: 25-06-2018
Publisher: Springer Science and Business Media LLC
Date: 03-12-2018
DOI: 10.1038/S41598-018-35206-9
Abstract: Settlement of invertebrates is a key process affecting the structure of marine communities and underpins the ability of benthic ecosystems to recover from disturbance. While it is known that specific crustose coralline algae (CCA) are important for settlement of some coral species, the role of algal chemical compounds versus surface microbial biofilms has long been ambiguous. Using a model system - a CCA of a genus that has been shown to induce high levels of settlement of Acropora corals ( Titanoderma cf . tessellatum ) and an abundant coral species ( Acropora millepora )- we show that chemical effects of CCA are stronger than those from CCA surface microbial biofilms as drivers of coral settlement. Biofilms contributed to some extent to larval settlement via synergistic effects, where microbial cues were dependent on the CCA primary metabolism (production of dissolved organic carbon). We propose that optimal coral settlement is caused by complex biochemical communications among CCA, their epiphytic microbial community and coral larvae.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.TREE.2016.02.014
Abstract: Sharks are considered the apex predator of coral reefs, but the consequences of their global depletion are uncertain. Here we explore the ecological roles of sharks on coral reefs and, conversely, the importance of reefs for sharks. We find that most reef-associated shark species do not act as apex predators but instead function as mesopredators along with a erse group of reef fish. While sharks perform important direct and indirect ecological roles, the evidence to support hypothesised shark-driven trophic cascades that benefit corals is weak and equivocal. Coral reefs provide some functional benefits to sharks, but sharks do not appear to favour healthier reef environments. Restoring populations of sharks is important and can yet deliver ecological surprise.
Publisher: Springer Science and Business Media LLC
Date: 02-08-2017
Publisher: Copernicus GmbH
Date: 16-02-2023
Publisher: Inter-Research Science Center
Date: 12-07-2013
DOI: 10.3354/MEPS10325
Publisher: Wiley
Date: 05-12-2022
DOI: 10.1002/LNO.12254
Abstract: With rubble predicted to increase on coral reefs worldwide, we review the physical, biological, and ecological dynamics of rubble beds, with a focus on how rubble generation, mobilization, binding, and coral recruitment is expected to change on future reefs. Major disturbances, including storms and coral bleaching, are predicted to increase in intensity and frequency, and—like localized impacts including blast fishing and ship groundings—generate large quantities of coral rubble. Reefs will have increasingly smaller recovery windows between successive disturbances, leading to persistence of unstable rubble beds on reefs. With more severe storms and increased bioerosion on future reefs, rubble mobilization thresholds will be met more often as smaller, less complex rubble pieces are generated. If rubble remains stable for adequate time, it can be bound by organisms including sponges and coralline algae, and eventually be cemented. However, increasing rubble mobilization frequencies will reduce the time available for binding, while changing ocean chemistry could reduce the efficacy of calcifying binders. Ultimately, increased rubble cover will negatively impact coral recruitment into rubble beds. Rubble mobilization abrades and smothers corals, and rubble beds typically experience altered environmental and ecological conditions to the coral frameworks that precede them. Several knowledge gaps exist in relation to improved rubble mobilization thresholds, binding rates and strengths, and coral survival in varying rubble bed types and hydrodynamic regimes. Addressing these knowledge gaps will improve our ability to predict the recovery trajectory of rubble beds and assess the need for stabilization interventions.
Publisher: Public Library of Science (PLoS)
Date: 11-02-2011
Publisher: Wiley
Date: 12-2018
DOI: 10.1002/FEE.1975
Publisher: Public Library of Science (PLoS)
Date: 26-05-2015
Publisher: Frontiers Media SA
Date: 18-03-2020
Publisher: Springer Science and Business Media LLC
Date: 16-04-2019
Publisher: Proceedings of the National Academy of Sciences
Date: 22-06-2023
Location: Australia
Start Date: 02-2014
End Date: 12-2017
Amount: $315,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2017
End Date: 12-2021
Amount: $396,000.00
Funder: Australian Research Council
View Funded Activity