ORCID Profile
0000-0003-3709-6344
Current Organisation
James Cook University
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Ecosystem Function | Environmental Science and Management | Environmental Management | Conservation and Biodiversity
Ecosystem Adaptation to Climate Change | Marine Flora, Fauna and Biodiversity | Ecosystem Assessment and Management of Marine Environments |
Publisher: Research Square Platform LLC
Date: 06-06-2022
DOI: 10.21203/RS.3.RS-1555992/V1
Abstract: Ocean warming is increasing the incidence, scale, and severity of global-scale coral bleaching and mortality, culminating in the third global coral bleaching event that occurred during record marine heatwaves of 2014-2017. While local effects of these events have been widely reported, the global implications remain unknown. Analysis of 15,066 reef surveys during 2014-2017 revealed that 80% of surveyed reefs experienced significant coral bleaching and 35% experienced significant coral mortality. The global extent of significant coral bleaching and mortality was assessed by extrapolating results from reef surveys using comprehensive remote-sensing data of regional heat stress. This model predicted that 51% of the world’s coral reefs suffered significant bleaching and 15% significant mortality, surpassing damage from any prior global bleaching event. These observations demonstrate that global warming’s widespread damage to coral reefs is accelerating and underscores the threat anthropogenic climate change poses for the irreversible transformation of these essential ecosystems.
Publisher: Springer Science and Business Media LLC
Date: 27-03-2018
DOI: 10.1038/S41598-018-23361-Y
Abstract: Infectious diseases not regulated by host density, such as vector-borne diseases, have the potential to drive population declines and extinctions. Here we test the vector potential of the snail Drupella sp. and butterflyfish Chaetodon plebeius for two coral diseases, black band (BBD) and brown band (BrB) disease. Drupella transmitted BrB to healthy corals in 40% of cases immediately following feeding on infected corals, and even in 12% of cases 12 and 24 hours following feeding. However, Drupella was unable to transmit BBD in either transmission treatment. In a field experiment testing the vector potential of naturally-occurring fish assemblages, equivalent numbers of caged and uncaged coral fragments became infected with either BrB, BBD or skeletal eroding band, indicating that corallivorous fish were unlikely to have caused transmission. In aquaria, C . plebeius did not transmit either BBD or BrB, even following extended feeding on both infected and healthy nubbins. A literature review confirmed only four known coral disease vectors, all invertebrates, corroborating our conclusion that polyp-feeding fishes are unlikely to be vectors of coral diseases. This potentially because polyp-feeding fishes produce shallow lesions, not allowing pathogens to invade coral tissues. In contrast, corallivorous invertebrates that create deeper feeding scars increase pathogens transmission.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 05-01-2018
Abstract: Coral bleaching occurs when stressful conditions result in the expulsion of the algal partner from the coral. Before anthropogenic climate warming, such events were relatively rare, allowing for recovery of the reef between events. Hughes et al. looked at 100 reefs globally and found that the average interval between bleaching events is now less than half what it was before. Such narrow recovery windows do not allow for full recovery. Furthermore, warming events such as El Niño are warmer than previously, as are general ocean conditions. Such changes are likely to make it more and more difficult for reefs to recover between stressful events. Science , this issue p. 80
Publisher: Wiley
Date: 28-04-2014
DOI: 10.1111/GCB.12571
Abstract: Thermal stress affects organism performance differently depending on the ambient temperature to which they are acclimatized, which varies along latitudinal gradients. This study investigated whether differences in physiological responses to temperature are consistent with regional differences in temperature regimes for the stony coral Oculina patagonica. To resolve this question, we experimentally assessed how colonies originating from four different locations characterized by >3 °C variation in mean maximum annual temperature responded to warming from 20 to 32 °C. We assessed plasticity in symbiont identity, density, and photosynthetic properties, together with changes in host tissue biomass. Results show that, without changes in the type of symbiont hosted by coral colonies, O. patagonica has limited capacity to acclimatize to future warming. We found little evidence of variation in overall thermal tolerance, or in thermal optima, in response to spatial variation in ambient temperature. Given that the invader O. patagonica is a relatively new member of the Mediterranean coral fauna, our results also suggest that coral populations may need to remain isolated for a long period of time for thermal adaptation to potentially take place. Our study indicates that for O. patagonica, mortality associated with thermal stress manifests primarily through tissue breakdown under moderate but prolonged warming (which does not impair symbiont photosynthesis and, therefore, does not lead to bleaching). Consequently, projected global warming is likely to cause repeat incidents of partial and whole colony mortality and might drive a gradual range contraction of Mediterranean corals.
Publisher: The Company of Biologists
Date: 15-03-2012
DOI: 10.1242/JEB.061002
Abstract: Coral reefs exhibit marked spatial and temporal variability, and coral reef organisms exhibit trade-offs in functional traits that influence demographic performance under different combinations of abiotic environmental conditions. In many systems, trait trade-offs are modelled using an energy and/or nutrient allocation framework. However, on coral reefs, differences in biomechanical vulnerability have major demographic implications, and indeed are believed to play an essential role in mediating species coexistence because highly competitive growth forms are vulnerable to physical dislodgment events that occur with high frequency (e.g. annual summer storms). Therefore, an integrated energy allocation and biomechanics framework is required to understand the effect of physical environmental gradients on species’ demographic performance. However, on coral reefs, as in most ecosystems, the effects of environmental conditions on organisms are measured in different currencies (e.g. lipid accumulation, survival and number of gametes), and thus the relative contributions of these effects to overall capacity for population growth are not readily apparent. A comprehensive assessment of links between the environment and the organism, including those mediated by biomechanical processes, must convert environmental effects on in idual-level performance (e.g. survival, growth and reproduction) into a common currency that is relevant to the capacity to contribute to population growth. We outline such an approach by considering the population-level performance of scleractinian reef corals over a hydrodynamic gradient, with a focus on the integrating the biomechanical determinants of size-dependent coral colony dislodgment as a function of flow, with the effects of flow on photosynthetic energy acquisition and respiration.
Publisher: Springer Netherlands
Date: 09-11-2010
Publisher: Springer Science and Business Media LLC
Date: 29-05-2018
DOI: 10.1038/S41598-018-26535-W
Abstract: Coral reefs face many stressors associated with global climate change, including increasing sea surface temperature and ocean acidification. Excavating sponges, such as Cliona spp., are expected to break down reef substrata more quickly as seawater becomes more acidic. However, increased bioerosion requires that Cliona spp. maintain physiological performance and health under continuing ocean warming. In this study, we exposed C. orientalis to temperature increments increasing from 23 to 32 °C. At 32 °C, or 3 °C above the maximum monthly mean (MMM) temperature, sponges bleached and the photosynthetic capacity of Symbiodinium was compromised, consistent with sympatric corals. Cliona orientalis demonstrated little capacity to recover from thermal stress, remaining bleached with reduced Symbiodinium density and energy reserves after one month at reduced temperature. In comparison, C. orientalis was not observed to bleach during the 2017 coral bleaching event on the Great Barrier Reef, when temperatures did not reach the 32 °C threshold. While C. orientalis can withstand current temperature extremes ( °C above MMM) under laboratory and natural conditions, this species would not survive ocean temperatures projected for 2100 without acclimatisation or adaptation (≥3 °C above MMM). Hence, as ocean temperatures increase above local thermal thresholds, C. orientalis will have a negligible impact on reef erosion.
Publisher: Springer Science and Business Media LLC
Date: 02-12-2022
Publisher: Public Library of Science (PLoS)
Date: 25-05-2012
Publisher: Elsevier BV
Date: 08-2021
Publisher: Wiley
Date: 04-2008
DOI: 10.1890/07-1272.1
Abstract: Morphological plasticity in response to environmental heterogeneity may be performance enhancing or may simply result from an intrinsic instability in morphology during development. Although patterns of morphological change are well documented for numerous taxa, it is often unclear whether this plasticity enhances the performance of organisms in the habitat to which they have acclimatized. Reef-building corals are an ideal model system in which to investigate this question. We here develop a three-dimensional geometric model and present a comprehensive photosynthesis data set with experimentally calibrated photosynthesis models that predicts energy acquisition by foliose corals as a function of colony shape. This allows us to assess the extent to which changes in colony morphology along an environmental gradient track the predicted optimal colony morphologies. Our results provide strong evidence that phenotypic plasticity in foliose corals optimizes photosynthetic energy acquisition and is not simply a mechanism to increase light capture. We show that the optimal morphology is constrained at the boundaries of the environmental gradient, with non-optimal morphologies in these habitats having greatly reduced energy acquisition. However, at the center of the environmental gradient, flexibility in photophysiology allows energy acquisition to be very similar for multiple morphologies. Our results highlight the importance of phenotypic plasticity at multiple scales. Variation in overall morphology is important at niche boundaries at which conditions are consistently more stressful, whereas physiological flexibility is important in intermediate and less predictable habitats in which a rapid and reversible response to environmental fluctuations is required.
Publisher: Elsevier BV
Date: 11-2012
DOI: 10.1016/J.CBPA.2012.07.002
Abstract: Reproduction in vertebrates is an energy-demanding process that is mediated by endogenous hormones and potentially results in oxidative stress. The primary aim of this study was to quantify the relationship between oxidative stress parameters (antioxidant capacity and levels of reactive oxygen metabolites) and circulating testosterone and cortisol in a common and widespread teleost fish, the brown trout (Salmo trutta, L.). Results show that trout with higher testosterone levels prior to spawning have higher levels of oxidative damage at the time that they spawn (although by the time of spawning testosterone levels had dropped, leading to a negative relationship between testosterone and oxidative damage at that time). Cortisol levels were not directly related to oxidative damage or antioxidant capacity, but concentrations of this hormone were positively related to levels of fungal infection, which was itself associated both with lower antioxidant capacity and lower levels of oxidative damage. These results highlight the complexity of interactions between different components of the endocrine system and metabolism and suggest that caution be used in interpreting relationships between a single hormone and indicators of oxidative balance or other fitness proxies.
Publisher: Wiley
Date: 23-11-2017
DOI: 10.1111/IVB.12199
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.ZOOL.2019.02.007
Abstract: Current research highlights the importance of associated microbes in contributing to the functioning, health, and even adaptation of their animal, plant, and fungal hosts. As such, we are witnessing a shift in research that moves away from focusing on the eukaryotic host sensu stricto to research into the complex conglomerate of the host and its associated microorganisms (i.e., microbial eukaryotes, archaea, bacteria, and viruses), the so-called metaorganism, as the biological entity. While recent research supports and encourages the adoption of such an integrative view, it must be understood that microorganisms are not involved in all host processes and not all associated microorganisms are functionally important. As such, our intention here is to provide a critical review and evaluation of perspectives and limitations relevant to studying organisms in a metaorganism framework and the functional toolbox available to do so. We note that marker gene-guided approaches that primarily characterize microbial ersity are a first step in delineating associated microbes but are not sufficient to establish proof of their functional relevance. More sophisticated tools and experiments are necessary to reveal the specific functions of associated microbes. This can be accomplished through the study of metaorganisms in less complex environments, the targeted manipulation of microbial associates, or work at the mechanistic level with the toolbox available in model systems. We conclude that the metaorganism framework is a powerful new concept to help provide answers to longstanding biological questions such as the evolution and ecology of organismal complexity and the importance of organismal symbioses to ecosystem functioning. The intricacy of the metaorganism requires a holistic framework combining reductionist and integrative approaches to resolve the structure and function of its member species and to disclose the various roles that microorganisms play in the biology of their hosts.
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.MARPOLBUL.2019.04.070
Abstract: Land-based sources contribute approximately 80% of anthropogenic debris in marine environments. A main pathway is believed to be rivers and storm-water systems, yet this input is rarely quantified. We aimed to quantify the abundance of land-based debris entering a river system through storm drains in an urban area of tropical Australia. To account for seasonal variability, debris was quantified pre, post and during the wet season from 2014 to 2017. Plastic items within the river were compared to those in adjacent parks to assess similarities in debris composition. A total of 27,943 items were collected (92% plastic). Debris loads in the post-wet seasons were significantly higher than the wet-season. Furthermore, variability in the portion of debris found in nearby parks compared to the river suggests that factors other than rainfall, play a role in debris abundance. These results can be used to identify targeted management strategies to reduce debris loads.
Publisher: The Company of Biologists
Date: 15-07-2010
DOI: 10.1242/JEB.040147
Abstract: This study quantifies the relative contributions of autotrophy and heterotrophy to the energy budget of the temperate scleractinian species Cladocora caespitosa Linnaeus 1767. Colonies were incubated under different light and feeding regimes, and changes in carbon acquisition through photosynthesis and feeding were measured during a 2-month time period. This approach allowed us to quantify the rate at which adjustments to physiology occurred, as well as the magnitude of up- or downregulation of both feeding modes. In addition, we explored how shifts in carbon acquisition mode influenced tissue biomass (protein content), energy stores (lipid content) and colony growth (calcification). Increases in feeding capacity during prolonged exposure to darkness were correlated with decreases in photosynthetic capacity. However, feeding effort did not decrease when photosynthesis was high. In fact, feeding was maximal under high light conditions when food was not available. During starvation, colonies used their lipid stores to partially meet their metabolic requirements. Colonies kept in low light used nutrients from feeding to supplement calcification, whereas those kept at high light converted carbon from feeding into tissue biomass. This work provides the first estimates of rates of adjustment of heterotrophic feeding capacity in a Mediterranean scleractinian coral. For the study species, flexibility in carbon acquisition through heterotrophy was approximately equal to flexibility in photosynthesis both in magnitude and in the rate at which physiological adjustments occurred. The ability to alter feeding effort rapidly and strongly may explain the wide depth distribution of C. caespitosa, and its ability to survive in turbid coastal waters where light is often limited.
Publisher: Springer Science and Business Media LLC
Date: 23-06-2021
Publisher: Inter-Research Science Center
Date: 23-01-2020
DOI: 10.3354/MEPS13184
Publisher: CRC Press
Date: 15-11-2020
Publisher: Inter-Research Science Center
Date: 05-10-2011
DOI: 10.3354/MEPS09271
Publisher: Elsevier
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 02-06-2017
DOI: 10.1038/S41598-017-02196-Z
Abstract: Decreasing coral cover on the Great Barrier Reef (GBR) may provide opportunities for rapid growth and expansion of other taxa. The bioeroding sponges Cliona spp. are strong competitors for space and may take advantage of coral bleaching, damage, and mortality. Benthic surveys of the inshore GBR (2005–2014) revealed that the percent cover of the most abundant bioeroding sponge species, Cliona orientalis , has not increased. However, considerable variation in C . orientalis cover, and change in cover over time, was evident between survey locations. We assessed whether biotic or environmental characteristics were associated with variation in C . orientalis distribution and abundance. The proportion of fine particles in the sediments was negatively associated with the presence-absence and the percent cover of C . orientalis , indicating that the sponge requires exposed habitat. The cover of corals and other sponges explained little variation in C . orientalis cover or distribution. The fastest increases in C . orientalis cover coincided with the lowest macroalgal cover and chlorophyll a concentration, highlighting the importance of macroalgal competition and local environmental conditions for this bioeroding sponge. Given the observed distribution and habitat preferences of C . orientalis , bioeroding sponges likely represent site-specific – rather than regional – threats to corals and reef accretion.
Publisher: Pensoft Publishers
Date: 21-03-2017
Publisher: Springer Science and Business Media LLC
Date: 05-12-2016
DOI: 10.1038/SREP38112
Abstract: Symbiotic scleractinian corals are particularly affected by climate change stress and respond by bleaching (losing their symbiotic dinoflagellate partners). Recently, the energetic status of corals is emerging as a particularly important factor that determines the corals’ vulnerability to heat stress. However, detailed studies of coral energetic that trace the flow of carbon from symbionts to host are still sparse. The present study thus investigates the impact of heat stress on the nutritional interactions between dinoflagellates and coral Stylophora pistillata maintained under auto- and heterotrophy. First, we demonstrated that the percentage of autotrophic carbon retained in the symbionts was significantly higher during heat stress than under non-stressful conditions, in both fed and unfed colonies. This higher photosynthate retention in symbionts translated into lower rates of carbon translocation, which required the coral host to use tissue energy reserves to sustain its respiratory needs. As calcification rates were positively correlated to carbon translocation, a significant decrease in skeletal growth was observed during heat stress. This study also provides evidence that heterotrophic nutrient supply enhances the re-establishment of normal nutritional exchanges between the two symbiotic partners in the coral S. pistillata , but it did not mitigate the effects of temperature stress on coral calcification.
Publisher: Cold Spring Harbor Laboratory
Date: 04-02-2020
DOI: 10.1101/2020.02.03.929521
Abstract: Structurally complex habitats tend to contain more species and higher total abundances than simple habitats. This ecological paradigm is grounded in first principles: species richness scales with area, and surface area and niche density increase with three-dimensional complexity. Here we present a geometric basis for surface habitats that unifies ecosystems and spatial scales. The theory is framed by fundamental geometric constraints among three structure descriptors—surface height, rugosity and fractal dimension—and explains 98% of surface variation in a structurally complex test system: coral reefs. We then show how coral bio ersity metrics (species richness, total abundance and probability of interspecific encounter) vary over the theoretical structure descriptor plane, demonstrating the value of the theory for predicting the consequences of natural and human modifications of surface structure.
Publisher: Springer Science and Business Media LLC
Date: 15-10-2017
DOI: 10.1007/S00442-016-3753-8
Abstract: Removal of predators is often hypothesized to alter community structure through trophic cascades. However, despite recent advances in our understanding of trophic cascades, evidence is often circumstantial on coral reefs because fishing pressure frequently co-varies with other anthropogenic effects, such as fishing for herbivorous fishes and changes in water quality due to pollution. Australia's outer Great Barrier Reef (GBR) has experienced fishing-induced declines of apex predators and mesopredators, but pollution and targeting of herbivorous fishes are minimal. Here, we quantify fish and benthic assemblages across a fishing-induced predator density gradient on the outer GBR, including apex predators and mesopredators to herbivores and benthic assemblages, to test for evidence of trophic cascades and alternative hypotheses to trophic cascade theory. Using structural equation models, we found no cascading effects from apex predators to lower trophic levels: a loss of apex predators did not lead to higher levels of mesopredators, and this did not suppress mobile herbivores and drive algal proliferation. Likewise, we found no effects of mesopredators on lower trophic levels: a decline of mesopredators was not associated with higher abundances of algae-farming damselfishes and algae-dominated reefs. These findings indicate that top-down forces on coral reefs are weak, at least on the outer GBR. We conclude that predator-mediated trophic cascades are probably the exception rather than the rule in complex ecosystems such as the outer GBR.
Publisher: Public Library of Science (PLoS)
Date: 03-2018
Publisher: The Royal Society
Date: 08-01-2020
Abstract: The disturbance regimes of ecosystems are changing, and prospects for continued recovery remain unclear. New assemblages with altered species composition may be deficient in key functional traits. Alternatively, important traits may be sustained by species that replace those in decline (response ersity). Here, we quantify the recovery and response ersity of coral assemblages using case studies of disturbance in three locations. Despite return trajectories of coral cover, the original assemblages with erse functional attributes failed to recover at each location. Response ersity and the reassembly of trait space was limited, and varied according to biogeographic differences in the attributes of dominant, rapidly recovering species. The deficits in recovering assemblages identified here suggest that the return of coral cover cannot assure the reassembly of reef trait ersity, and that shortening intervals between disturbances can limit recovery among functionally important species.
Publisher: Springer Science and Business Media LLC
Date: 23-11-2013
Publisher: Inter-Research Science Center
Date: 26-04-2018
DOI: 10.3354/MEPS12525
Publisher: Elsevier BV
Date: 05-2021
Publisher: Wiley
Date: 21-05-2009
Publisher: Wiley
Date: 07-2018
DOI: 10.1111/GEB.12729
Publisher: Springer Science and Business Media LLC
Date: 10-09-2014
DOI: 10.1007/S00442-014-3065-9
Abstract: Mutualistic symbioses are ubiquitous in nature and facilitate high bio ersity and productivity of ecosystems by enhancing the efficiency of energy and nutrient use within ecological communities. For ex le, small groups of fish that inhabit coral colonies in reef ecosystems potentially enhance coral growth through defense from coral predators, aeration of coral tissue and nutrient provisioning. This study examines whether the prevalence and consequences of fish-coral interactions vary among sites with different environmental conditions in a coral reef lagoon, using the humbug damselfish Dascyllus aruanus and its preferred coral host Pocillopora damicornis as a study system. Using a field experiment, we tested the site-specific effects of D. aruanus on coral growth, and show that the cost-benefit ratio for corals hosting fish varies with local environmental variation. Results of this study also demonstrate that fish prefer to inhabit coral colonies with particular branch-spacing characteristics, and that the local abundance of D. aruanus influences the proportion of coral colonies within a site that are occupied by fish rather than increasing the number of fish per colony. We also show that corals consistently benefit from hosting D. aruanus via defense from predation by corallivorous butterflyfish, regardless of local environmental conditions. These findings highlight the need to consider the potential for multiple scale- and state-dependent interaction effects when examining the ecology of fish-coral associations. We suggest that fluctuating cost-benefit ratios for species interactions may contribute to the maintenance of different colony phenotypes within coral populations.
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.MARPOLBUL.2016.10.011
Abstract: Successful reproduction and larval dispersal are important for the persistence of marine invertebrate populations, and these early life history processes can be sensitive to marine pollution. Coal is emerging as a contaminant of interest due to the proximity of ports and shipping lanes to coral reefs. To assess the potential hazard of this contaminant, gametes, newly developed embryos, larvae and juveniles of the coral Acropora tenuis were exposed to a range of coal leachate, suspended coal, and coal smothering treatments. Fertilisation was the most sensitive reproductive process tested. Embryo survivorship decreased with increasing suspended coal concentrations and exposure duration, effects on larval settlement varied between treatments, while effects on juvenile survivorship were minimal. Leachate exposures had negligible effects on fertilisation and larval settlement. These results indicate that coral recruitment could be affected by spills that produce plumes of suspended coal particles which interact with gametes and embryos soon after spawning.
Publisher: Wiley
Date: 04-02-2022
DOI: 10.1111/GCB.16093
Abstract: Coral reefs are iconic ecosystems with immense ecological, economic and cultural value, but globally their carbonate‐based skeletal construction is threatened by ocean acidification (OA). Identifying coral species that have specialised mechanisms to maintain high rates of calcification in the face of declining seawater pH is of paramount importance in predicting future species composition, and growth of coral reefs. Here, we studied multiple coral species from two distinct volcanic CO 2 seeps in Papua New Guinea to assess their capacity to control their calcifying fluid (CF) chemistry. Several coral species living under conditions of low mean seawater pH, but with either low or high variability in seawater pH, were examined and compared with those living in ‘normal’ (non‐seep) ambient seawater pH. We show that when mean seawater pH is low but highly variable, corals have a greater ability to maintain constant pH cf in their CF, but this characteristic was not linked with changes in abundance. Within less variable low pH seawater, corals with limited reductions in pH cf at the seep sites compared with controls tended to be more abundant at the seep site than at the control site. However, this finding was strongly influenced by a single species ( Montipora foliosa ), which was able to maintain complete pH cf homeostasis. Overall, although our findings indicate that there might be an association between ecological success and greater pH cf homeostasis, further research with additional species and at more sites with differing seawater pH regimes is required to solidify inferences regarding coral ecological success under future OA.
Publisher: Springer Science and Business Media LLC
Date: 13-05-2016
DOI: 10.1038/SREP25894
Abstract: Coal is a principal fossil fuel driving economic and social development and increases in global coal shipments have paralleled expansion of the industry. To identify the potential harm associated with chronic marine coal contamination, three taxa abundant in tropical marine ecosystems (the coral Acropora tenuis , the reef fish Acanthochromis polyacanthus and the seagrass Halodule uninervis ) were exposed to five concentrations (0–275 mg coal l −1 ) of suspended coal dust ( μm) over 28 d. Results demonstrate that chronic coal exposure can cause considerable lethal effects on corals and reductions in seagrass and fish growth rates. Coral survivorship and seagrass growth rates were inversely related to increasing coal concentrations (≥38 mg coal l −1 ) and effects increased between 14 and 28 d, whereas fish growth rates were similarly depressed at all coal concentrations tested. This investigation provides novel insights into direct coal impacts on key tropical taxa for application in the assessment of risks posed by increasing coal shipments in globally threatened marine ecosystems.
Publisher: Springer Science and Business Media LLC
Date: 10-12-2018
Publisher: Inter-Research Science Center
Date: 02-06-2022
DOI: 10.3354/MEPS14055
Abstract: Climate change impacts and light attenuation from suspended sediments, due to runoff, natural resuspension or dredging, can both impede the replenishment of coral populations. Here we tested the independent and combined impacts of climate change (current temperature and dissolved CO 2 , and 2 future climate scenarios) and a 1 mo long light attenuation period at 5 different light levels (0.1 to 4 mol photons m -2 d -1 ) on early Acropora millepora recruits. Additionally, we evaluated whether the effects were age dependent by comparing responses of recruits that were 1 mo old (‘early attenuation’) vs. 2 mo old (‘late attenuation’). Recruit survival, size and Symbiodiniaceae densities increased slightly under moderate future climate conditions (current temperature +0.44°C, 692 ppm pCO 2 ), but decreased under a more severe climate scenario (+0.94°C, 985 ppm pCO 2 ). Light attenuation significantly decreased recruit survival, size and Symbiodiniaceae densities only for recruits exposed to the late attenuation, suggesting an increasing reliance on photosynthesis as recruits age. Under the more severe climate scenario tested, recruit survival was diminished by both climate change (≤18 ± 4% [SE] in the early attenuation) and light limitation (≤32 ± 6% in the late attenuation) compared with controls. However, there was no interaction between future climate scenarios and light attenuation, indicating that these effects were additive. This study demonstrates the potential effects of light limitation and future climate conditions on coral recruitment success and highlights the need to manage the timing of sediment-generating activities near reefs to optimise light availability for several months post settlement.
Publisher: Wiley
Date: 02-2005
Publisher: Frontiers Media SA
Date: 27-11-2017
Publisher: Inter-Research Science Center
Date: 09-01-2020
DOI: 10.3354/MEPS13167
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: Inter-Research Science Center
Date: 06-02-2020
DOI: 10.3354/MEPS13203
Abstract: Thermal performance curves describe the relationship between temperature and the rate of biological processes. These relationships can vary among species and environments, allowing organisms to acclimatize to their local thermal regime. This study quantified the seasonal variation in the thermal performance of several coral and symbiont-dominated physiological traits for the thermally tolerant coral species Porites cylindrica and the thermally sensitive coral species Acropora valenciennesi . Photosynthesis rates, respiration rates, maximum photosystem II (PSII) quantum yield and electron transport rates were measured in winter and summer on coral fragments exposed to an acute temperature increase and decrease up to 5°C above and below the average seawater temperature in each season. Results showed that colonies of A. valenciennesi acclimated primarily by shifting their optimal temperature to a higher temperature in summer, whereas colonies of P. cylindrica had broader thermal breadth during summer. For symbionts within both species, performance was higher at all temperatures in summer, while the thermal optima and performance breadth remained unchanged. Despite these changes in thermal performance, the thermal optima of most traits did not match the ambient environmental temperature, but fell between the summer and winter temperatures. Overall, these results showed that both coral species were physiologically plastic in response to temperature change, but that there are constraints on the rate or capacity for acclimation that prevent a perfect match between the average temperature of the environment and the thermal optimum of the species.
Publisher: Springer Science and Business Media LLC
Date: 04-2019
DOI: 10.1038/S41586-019-1081-Y
Abstract: Changes in disturbance regimes due to climate change are increasingly challenging the capacity of ecosystems to absorb recurrent shocks and reassemble afterwards, escalating the risk of widespread ecological collapse of current ecosystems and the emergence of novel assemblages
Publisher: Wiley
Date: 03-2009
DOI: 10.1890/07-2010.1
Abstract: The “fundamental niche” is the range of conditions under which an organism can survive and reproduce, measured in the absence of biotic interactions. Niche measurements are often based on statistical relationships between species presence and measured environmental variables, or inferred from measured responses of species along hypothesized niche axes. In this study, we use novel, process‐based models of how irradiance and gas diffusion influence photosynthesis and respiration to predict niche dimensions for three coral species: Acropora nasuta , Montipora foliosa , and Leptoria phrygia . We use a combination of mathematical modeling, laboratory experiments, and field observations to establish the link between energy acquisition and the dominant environmental gradients on reefs: light intensity and water flow velocity. Our approach allows us to quantify how the shape of the niche varies in response to light and flow conditions. The model predicts that, due to its higher photosynthetic capacity, the branching coral A. nasuta has a positive energy balance over a wider range of conditions than both a massive species ( L. phrygia ) and a foliose species ( M. foliosa ). Moreover, colony size influences niche width, with larger colonies of all three species achieving a positive energy balance over a broader range of conditions than small colonies. Comparison of model predictions with field data demonstrated that tissue biomass and reproductive output are significantly and positively correlated with predicted energy acquisition. These results show how interactions between light and flow determine organism performance along environmental gradients on coral reefs. In addition, this study demonstrates the utility of process‐based models for quantifying how physiology influences ecology, and for predicting the ecological consequences of varying environmental conditions.
Publisher: Public Library of Science (PLoS)
Date: 14-12-2018
Publisher: Public Library of Science (PLoS)
Date: 21-09-2018
Publisher: Wiley
Date: 05-09-2021
DOI: 10.1111/GCB.15829
Abstract: Anthropogenic climate change is a rapidly intensifying selection pressure on bio ersity across the globe and, particularly, on the world's coral reefs. The rate of adaptation to climate change is proportional to the amount of phenotypic variation that can be inherited by subsequent generations (i.e., narrow‐sense heritability, h 2 ). Thus, traits that have higher heritability (e.g., h 2 0.5) are likely to adapt to future conditions faster than traits with lower heritability (e.g., h 2 0.1). Here, we synthesize 95 heritability estimates across 19 species of reef‐building corals. Our meta‐analysis reveals low heritability ( h 2 0.25) of gene expression metrics, intermediate heritability ( h 2 = 0.25–0.50) of photochemistry, growth, and bleaching, and high heritability ( h 2 0.50) for metrics related to survival and immune responses. Some of these values are higher than typically observed in other taxa, such as survival and growth, while others were more comparable, such as gene expression and photochemistry. There was no detectable effect of temperature on heritability, but narrow‐sense heritability estimates were generally lower than broad‐sense estimates, indicative of significant non‐additive genetic variation across traits. Trait heritability also varied depending on coral life stage, with bleaching and growth in juveniles generally having lower heritability compared to bleaching and growth in larvae and adults. These differences may be the result of previous stabilizing selection on juveniles or may be due to constrained evolution resulting from genetic trade‐offs or genetic correlations between growth and thermotolerance. While we find no evidence that heritability decreases under temperature stress, explicit tests of the heritability of thermal tolerance itself—such as coral thermal reaction norm shape—are lacking. Nevertheless, our findings overall reveal high trait heritability for the majority of coral traits, suggesting corals may have a greater potential to adapt to climate change than has been assumed in recent evolutionary models.
Publisher: Springer Science and Business Media LLC
Date: 04-2018
DOI: 10.1038/S41586-018-0041-2
Abstract: Global warming is rapidly emerging as a universal threat to ecological integrity and function, highlighting the urgent need for a better understanding of the impact of heat exposure on the resilience of ecosystems and the people who depend on them
Publisher: Public Library of Science (PLoS)
Date: 11-05-2011
Publisher: Springer Science and Business Media LLC
Date: 17-02-2016
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.CUB.2018.09.025
Abstract: Sustaining ecological functions as bio ersity changes will be a major challenge in the 21st century [1]. However, our understanding of the relationship between bio ersity and ecosystem function is still emerging on tropical coral reefs [2], where reef-building corals form highly productive assemblages [3, 4] and species respond in different ways to their neighbors [5] and their environment (e.g., water flow) [6]. Experimental coral communities were assembled to quantify the performance of coral colonies with and without neighbors and in the presence of conspecifics versus heterospecifics. Under higher flow, we identified a positive effect of coral species richness on primary productivity (gross and net photosynthesis) indicated by a 53% increase in productivity in multispecies assemblages (2-4 species) relative to monocultures. Productivity in monocultures was predicted by surface areas associated with different species morphologies. In contrast, multispecies assemblages maintained high levels of productivity even in the absence of the most productive species, reflecting non-additive effects of species richness on community functioning. Assemblage performances were regulated by positive and negative interactions between colonies, with many colonies performing better among heterospecific neighbors than in isolation (facilitation). Facilitation occurred primarily among flow-sensitive taxa with simple morphologies and did not occur under lower flow, suggesting that modifications to flow microclimates by corals generated beneficial, interspecific interactions. Our results show that competition and facilitation among neighbors may be important mechanisms regulating coral assemblage productivity in variable environments. Furthermore, shifts in the ersity and identity of neighbors can impair these interactions, with potentially widespread consequences for coral community functioning.
Publisher: Elsevier BV
Date: 06-2009
Publisher: Springer Science and Business Media LLC
Date: 05-11-2009
Publisher: The Royal Society
Date: 04-2020
DOI: 10.1098/RSOS.192074
Abstract: Mutualisms play a critical role in ecological communities however, the importance and prevalence of mutualistic associations can be modified by external stressors. On coral reefs, elevated sediment deposition can be a major stressor reducing the health of corals and reef resilience. Here, we investigated the influence of severe sedimentation on the mutualistic relationship between small damselfishes ( Pomacentrus moluccensis and Dascyllus aruanus ) and their coral host ( Pocillopora damicornis ). In an aquarium experiment, corals were exposed to sedimentation rates of approximately 100 mg cm −2 d −1 , with and without fishes present, to test whether: (i) fishes influence the accumulation of sediments on coral hosts, and (ii) fishes moderate partial colony mortality and/or coral tissue condition. Colonies with fishes accumulated much less sediment compared with colonies without fishes, and this effect was strongest for colonies with D. aruanus (fivefold less sediment than controls) as opposed to P. moluccensis (twofold less sediment than controls). Colonies with symbiont fishes also had up to 10-fold less sediment-induced partial mortality, as well as higher chlorophyll and protein concentrations. These results demonstrate that fish mutualisms vary in the strength of their benefits, and indicate that some mutualistic or facilitative interactions might become more important for species health and resilience at high-stress levels.
Publisher: Research Square Platform LLC
Date: 14-09-2023
Publisher: Springer Science and Business Media LLC
Date: 20-01-2013
Publisher: Springer Science and Business Media LLC
Date: 09-01-2017
DOI: 10.1038/SREP40288
Abstract: Climate change, including ocean acidification (OA), represents a major threat to coral-reef ecosystems. Although previous experiments have shown that OA can negatively affect the fitness of reef corals, these have not included the long-term effects of competition for space on coral growth rates. Our multispecies year-long study subjected reef-building corals from the Gulf of Aqaba (Red Sea) to competitive interactions under present-day ocean pH (pH 8.1) and predicted end-of-century ocean pH (pH 7.6). Results showed coral growth is significantly impeded by OA under intraspecific competition for five out of six study species. Reduced growth from OA, however, is negligible when growth is already suppressed in the presence of interspecific competition. Using a spatial competition model, our analysis indicates shifts in the competitive hierarchy and a decrease in overall coral cover under lowered pH. Collectively, our case study demonstrates how modified competitive performance under increasing OA will in all likelihood change the composition, structure and functionality of reef coral communities.
Publisher: Brill
Date: 30-09-2016
DOI: 10.1163/18759866-08504002
Abstract: The scleractinian family Lobophylliidae is undergoing a major taxonomic revision thanks to the combination of molecular and morphological data. In this study, we investigate the evolutionary relationships and the macro- and micromorphology of six nominal coral species belonging to two of the nine molecular clades of the Lobophylliidae, clades A and B, and of Symphyllia wilsoni , a lobophylliid species analyzed from a molecular point of view for the first time. Sequence data from mitochondrial DNA (COI and the intergenic spacer between COI and l-rRNA), and nuclear DNA (histone H3 and ITS region) are used to generate robust molecular phylogenies and a median-joining haplotype network. Molecular results are strongly in agreement with detailed observations of gross- and fine-scale morphology of skeletons, leading to the formal revision of the genera Micromussa and Homophyllia and the description of two newly discovered zooxanthellate shallow-water species, Micromussa pacifica sp. nov. Benzoni & Arrigoni and Micromussa indiana sp. nov. Benzoni & Arrigoni, and a new genus, Australophyllia gen. nov. Benzoni & Arrigoni. In particular, Acanthastrea lordhowensis and Montastraea multipunctata are moved into Micromussa , A . hillae is synonymized with A . bowerbanki and is transferred to Homophyllia , and a revised diagnosis for both genera is provided. Micromussa pacifica sp. nov. is described from the Gambier Islands with its distribution spanning New Caledonia and eastern Australia. Despite a superficial resemblance with Homophyllia australis , it has distinctive macroand micromorphological septal features. Micromussa indiana sp. nov., previously identified as M . amakusensis , is here described from the Gulf of Aden and the southern Red Sea as a distinct species that is genetically separated from M . amakusensis and is morphologically distinct from the latter due to its smaller corallite size and lower number of septa. Finally, molecular trees show that S . wilsoni is closely related, but molecularly separated from clades A and B, and, also based on a unique combination of corallite and sub-corallite characters, the species is moved into Australophyllia gen. nov. These findings confirm the need for using both genetic and morphological datasets for the ongoing taxonomic revision of scleractinian corals.
Publisher: Springer Science and Business Media LLC
Date: 11-2009
Publisher: Springer Science and Business Media LLC
Date: 03-2017
DOI: 10.1038/NATURE21707
Abstract: During 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.
Publisher: Cambridge University Press (CUP)
Date: 2015
DOI: 10.1017/S1755267215001141
Abstract: Rare and cryptic species can be easily missed during ecological surveys of coral communities. This study reveals a disparity in the reported geographic range of a rare species, Echinomorpha nishihirai, between three different sources none of which are wholly consistent with the available published occurrence records. Discrepancies in the species ranges reported in two comprehensive online databases are greater for rare, compared with common, coral species, suggesting a need for a more cautious treatment of rare species in biogeographic studies.
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.ENVPOL.2019.113074
Abstract: Coral reefs are increasingly affected by the consequences of global change such as increasing temperatures or pollution. Lately, microplastics (i.e., fragments < 5 mm) have been identified as another potential threat. While previous studies have assessed short-term effects caused by high concentrations of microplastics, nothing is known about the long-term effects of microplastics under realistic concentrations. Therefore, a microcosm study was conducted and corals of the genera Acropora, Pocillopora, Porites, and Heliopora were exposed to microplastics in a concentration of 200 particles L
Publisher: CRC Press
Date: 26-08-2015
DOI: 10.1201/B18733
Publisher: Oxford University Press (OUP)
Date: 28-09-2015
Abstract: Changes in environmental conditions, such as those caused by elevated carbon dioxide (CO2), potentially alter the outcome of competitive interactions between species. This study aimed to understand how elevated CO2 could influence competitive interactions between hard and soft corals, by investigating growth and photosynthetic activity of Porites cylindrica (a hard coral) under elevated CO2 and in the presence of another hard coral and two soft coral competitors. Corals were collected from reefs around Orpheus and Pelorus Islands on the Great Barrier Reef, Australia. They were then exposed to elevated pCO2 for 4 weeks with two CO2 treatments: intermediate (pCO2 648) and high (pCO2 1003) compared with a control (unmanipulated seawater) treatment (pCO2 358). Porites cylindrica growth did not vary among pCO2 treatments, regardless of the presence and type of competitors, nor was the growth of another hard coral species, Acropora cerealis, affected by pCO2 treatment. Photosynthetic rates of P. cylindrica were sensitive to variations in pCO2, and varied between the side of the fragment facing the competitors vs. the side facing away from the competitor. However, variation in photosynthetic rates depended on pCO2 treatment, competitor identity, and whether the photosynthetic yields were measured as maximum or effective photosynthetic yield. This study suggests that elevated CO2 may impair photosynthetic activity, but not growth, of a hard coral under competition and confirms the hypothesis that soft corals are generally resistant to elevated CO2. Overall, our results indicate that shifts in the species composition in coral communities as a result of elevated CO2 could be more strongly related to the in idual tolerance of different species rather than a result of competitive interactions between species.
Publisher: Springer Science and Business Media LLC
Date: 29-03-2016
Abstract: Trait-based approaches advance ecological and evolutionary research because traits provide a strong link to an organism’s function and fitness. Trait-based research might lead to a deeper understanding of the functions of, and services provided by, ecosystems, thereby improving management, which is vital in the current era of rapid environmental change. Coral reef scientists have long collected trait data for corals however, these are difficult to access and often under-utilized in addressing large-scale questions. We present the Coral Trait Database initiative that aims to bring together physiological, morphological, ecological, phylogenetic and biogeographic trait information into a single repository. The database houses species- and in idual-level data from published field and experimental studies alongside contextual data that provide important framing for analyses. In this data descriptor, we release data for 56 traits for 1547 species, and present a collaborative platform on which other trait data are being actively federated. Our overall goal is for the Coral Trait Database to become an open-source, community-led data clearinghouse that accelerates coral reef research.
Publisher: Public Library of Science (PLoS)
Date: 13-01-2012
Publisher: Inter-Research Science Center
Date: 11-05-2006
DOI: 10.3354/MEPS313001
Publisher: Wiley
Date: 31-03-2018
DOI: 10.1111/MEC.14544
Abstract: Bioeroding sponges break down calcium carbonate substratum, including coral skeleton, and their capacity for reef erosion is expected to increase in warmer and more acidic oceans. However, elevated temperature can disrupt the functionally important microbial symbionts of some sponge species, often with adverse consequences for host health. Here, we provide the first detailed description of the microbial community of the bioeroding sponge Cliona orientalis and assess how the community responds to seawater temperatures incrementally increasing from 23°C to 32°C. The microbiome, identified using 16S rRNA gene sequencing, was dominated by Alphaproteobacteria, including a single operational taxonomic unit (OTU Rhodothalassium sp.) that represented 21% of all sequences. The "core" microbial community (taxa present in >80% of s les) included putative nitrogen fixers and ammonia oxidizers, suggesting that symbiotic nitrogen metabolism may be a key function of the C. orientalis holobiont. The C. orientalis microbiome was generally stable at temperatures up to 27°C however, a community shift occurred at 29°C, including changes in the relative abundance and turnover of microbial OTUs. Notably, this microbial shift occurred at a lower temperature than the 32°C threshold that induced sponge bleaching, indicating that changes in the microbiome may play a role in the destabilization of the C. orientalis holobiont. C. orientalis failed to regain Symbiodinium or restore its baseline microbial community following bleaching, suggesting that the sponge has limited ability to recover from extreme thermal exposure, at least under aquarium conditions.
Publisher: The Company of Biologists
Date: 2015
DOI: 10.1242/JEB.124396
Abstract: The symbiosis between corals and dinoflagellates promotes the rapid growth of corals in shallow tropical oceans, and the high overall productivity of coral reefs. The aim of this study was to quantify and understand variation in carbon acquisition and allocation among coral species. We measured multiple physiological traits (including symbiont density, calcification, photosynthesis and tissue composition) for the same coral fragments to facilitate direct comparisons between species (Stylophora pistillata, Pocillopora damicornis, Galaxea fascicularis, Turbinaria reniformis and Acropora sp.). Tissue protein content was highly sensitive to the availability of particulate food, increasing in fed colonies of all species. Despite among-species variation in physiology, and consistent effects of feeding on some traits, overall energy allocation to tissue compared with skeleton growth did not depend on food availability. Extrapolating from our results, estimated whole-assemblage carbon uptake varied& fold across different coral assemblages, but this variation was largely driven by differences in the tissue surface area of different colony morphologies, rather than to differences in surface-area specific physiological rates. Our results caution against drawing conclusions about reef productivity based solely on physiological rates measured per unit tissue surface area. Understanding the causes and consequences of among-species variation in physiological energetics provides insight into the mechanisms that underlie in the fluxes of organic matter within reefs, and between reefs and the open ocean.
Publisher: Inter-Research Science Center
Date: 04-08-2014
DOI: 10.3354/MEPS10836
Publisher: The Royal Society
Date: 17-06-2019
Abstract: Species have evolved different mechanisms to cope with spatial and temporal temperature variability. Species with broad geographical distributions may be thermal generalists that perform well across a broad range of temperatures, or they might contain subpopulations of locally adapted thermal specialists. We quantified the variation in thermal performance of two coral species, Porites cylindrica and Acropora spp., along a latitudinal gradient over which temperature varies by approximately 6°C. Photosynthesis rates, respiration rates, maximum quantum yield and maximum electron transport rates were measured on coral fragments exposed to an acute temperature increase and decrease up to 5°C above and below the local average temperature. Results showed geographical variation in the performance curves of both species at holobiont and symbiont level, but this did not lead to an alignment of the optimal temperature for performance with the average temperature of the local environment, suggesting suboptimal coral performance of these coral populations in summer. Furthermore, symbiont thermal performance generally had an optimum closer to the average environmental temperature than holobiont performance, suggesting that symbionts have a higher capacity for acclimatization than the coral host, and can aid the coral host when temperatures are unfavourable. This article is part of the theme issue ‘Physiological ersity, bio ersity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.TREE.2016.02.012
Abstract: Coral reefs are biologically erse and ecologically complex ecosystems constructed by stony corals. Despite decades of research, basic coral population biology and community ecology questions remain. Quantifying trait variation among species can help resolve these questions, but progress has been h ered by a paucity of trait data for the many, often rare, species and by a reliance on nonquantitative approaches. Therefore, we propose filling data gaps by prioritizing traits that are easy to measure, estimating key traits for species with missing data, and identifying 'supertraits' that capture a large amount of variation for a range of biological and ecological processes. Such an approach can accelerate our understanding of coral ecology and our ability to protect critically threatened global ecosystems.
Publisher: Springer Science and Business Media LLC
Date: 06-09-2013
DOI: 10.1007/S11120-013-9918-Y
Abstract: Changing light environments force photoautotroph cells, including coral symbionts, to acclimate to maintain photosynthesis. Photosystem II (PSII) is subjected to photoinactivation at a rate proportional to the incident light, and cells must adjust their rates of protein repair to counter this photoinactivation. We examined PSII function in the coral symbiont Symbiodinium to determine the effect of photoacclimation on their capacity for PSII repair. Colonies of the coral Stylophora pistillata were collected from moderate light environments on the Lizard Island reef (Queensland, Australia) and transported to a local field station, where they were assigned to lower or higher light regimes and allowed to acclimate for 2 weeks. Following this photoacclimation period, the low-light acclimated corals showed greater symbiont density, higher chlorophyll per symbiont cell, and higher photosystem II protein than high-light acclimated corals did. Subsequently, we treated the corals with lincomycin, an inhibitor of chloroplastic protein synthesis, and exposed them to a high-light treatment to separate the effect of de novo protein synthesis in PSII repair from intrinsic susceptibility to photoinactivation. Low-light acclimated corals showed a sharp initial drop in PSII function but inhibition of PSII repair provoked only a modest additional drop in PSII function, compared to uninhibited corals. In high-light acclimated corals inhibition of PSII repair provoked a larger drop in PSII function, compared to uninhibited high-light corals. The greater lincomycin effects in the corals pre-acclimated to high-light show that high-light leads to an increased reliance on the PSII repair cycle.
Publisher: Proceedings of the National Academy of Sciences
Date: 05-03-2018
Abstract: The wide variety of functional trait combinations among the world’s coral faunas can be represented by just a few dimensions of variation. The ersity of coral traits among these dimensions is consistently high along Pacific and Indian Ocean ersity gradients, despite a threefold decline in species richness (from approximately 600 to 200 species). Functional redundancy, defined as multiple species sharing similar arrays of traits, is highest in the central Indo-Pacific bio ersity hotspot. While these Indo-Pacific provinces are globally important reserves of coral reef resilience and function, peripheral species-poor regions are potentially more vulnerable to functional collapse, as indicated by a critical lack of redundancy among species and the reduced capacity for similar species to respond differently to chronic or acute stressors.
Publisher: Wiley
Date: 09-06-2024
DOI: 10.1111/ELE.14114
Abstract: Insights into assemblages that can persist in extreme environments are still emerging. Ocean warming and acidification select against species with low physiological tolerance (trait-based 'filtering'). However, intraspecific trait variation can promote species adaptation and persistence, with potentially large effects on assemblage structure. By s ling nine coral traits (four morphological, four tissue and one skeletal) along an offshore-inshore gradient in temperature and pH, we show that distantly related coral species undergo consistent intraspecific changes as they cross into warm, acidic environments. Intraspecific variation and species turnover each favoured colonies with greater tissue biomass, higher symbiont densities and reduced skeletal investments, indicating strong filtering on colony physiology within and across species. Physiological tissue traits were highly variable within species and were independent of morphology, enabling morphologically erse species to cross into sites of elevated temperature and acidity. Widespread intraspecific change can therefore counter the loss of bio ersity and morphological structure across a steep environmental gradient.
Publisher: Inter-Research Science Center
Date: 10-02-2011
DOI: 10.3354/MEPS08886
Publisher: Springer Science and Business Media LLC
Date: 23-07-2022
DOI: 10.1007/S00338-022-02286-Z
Abstract: Ocean acidification (OA) is a major threat to marine calcifying organisms. This manuscript gives an overview of the physiological effects of acidification on reef-building corals from a cellular to population scale. In addition, we present the first review of the indirect effects resulting from altered species interactions. We find that the direct effects of acidification are more consistently negative at larger spatial scales, suggesting an accumulation of sub-lethal physiological effects can result in notable changes at a population and an ecosystem level. We identify that the indirect effects of acidification also have the potential to contribute to declines in coral cover under future acidified conditions. Of particular concern for reef persistence are declines in the abundance of crustose coralline algae which can result in loss of stable substrate and settlement cues for corals, potentially compounding the direct negative effects on coral recruitment rates. In addition, an increase in the abundance of bioeroders and bioerosive capacity may compound declines in calcification and result in a shift towards net dissolution. There are significant knowledge gaps around many indirect effects, including changes in herbivory and associated coral–macroalgal interactions, and changes in habitat provision of corals to fish, invertebrates and plankton, and the impact of changes to these interactions for both in idual corals and reef bio ersity as structural complexity declines. This research highlights the potential of indirect effects to contribute to alterations in reef ecosystem functions and processes. Such knowledge will be critical for scaling-up the impacts of OA from in idual corals to reef ecosystems and for understanding the effects of OA on reef-dependent human societies.
Publisher: MDPI AG
Date: 15-11-2019
DOI: 10.3390/D11110219
Abstract: Associations between habitat-forming, branching scleractinian corals and damselfish have critical implications for the function and trophic dynamics of coral reef ecosystems. This study quantifies how different characteristics of reef habitat, and of coral morphology, determine whether fish occupy a coral colony. In situ surveys of aggregative damselfish–coral associations were conducted at 51 different sites distributed among 22 reefs spread along km of the Great Barrier Reef, to quantify interaction frequency over a large spatial scale. The prevalence of fish–coral associations between five damselfish (Chromis viridis, Dascyllus aruanus, Dascyllus reticulatus, Pomacentrus amboinensis and Pomacentrus moluccensis) and five coral species (Acropora spathulata, Acropora intermedia, Pocillopora damicornis, Seriatopora hystrix, and Stylophora pistillata) averaged ~30% across all corals, but ranged from % to 93% of small branching corals occupied at each site, depending on reef exposure levels and habitat. Surprisingly, coral cover was not correlated with coral occupancy, or total biomass of damselfish. Instead, the biomass of damselfish was two-fold greater on sheltered sites compared with exposed sites. Reef habitat type strongly governed these interactions with reef slope/base (25%) and shallow sand-patch habitats (38%) hosting a majority of aggregative damselfish-branching coral associations compared to reef flat (10%), crest (16%), and wall habitats (11%). Among the focal coral species, Seriatopora hystrix hosted the highest damselfish biomass (12.45 g per occupied colony) and Acropora intermedia the least (6.87 g per occupied colony). Analyses of local coral colony traits indicated that multiple factors governed colony usage, including spacing between colonies on the benthos, colony position, and colony branching patterns. Nevertheless, the morphological and habitat characteristics that determine whether or not a colony is occupied by fish varied among coral species. These findings illuminate the realized niche of one of the most important and abundant reef fish families and provide a context for understanding how fish–coral interactions influence coral population and community level processes.
Publisher: Springer Science and Business Media LLC
Date: 05-12-2016
Abstract: Scientific Data 3:160017 doi: 10.1038/sdata.2016.17 (2016) Published 29 March 2016 Updated 5 December 2017. The authors regret that Aaron Harmer was omitted in error from the author list of the original version of this Data Descriptor. This omission has now been corrected in the HTML and PDF versions.
Publisher: Springer Science and Business Media LLC
Date: 04-02-2015
Publisher: Springer Science and Business Media LLC
Date: 24-08-2020
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2014
End Date: 2020
Funder: Australian Research Council
View Funded ActivityStart Date: 10-2014
End Date: 12-2021
Amount: $28,000,000.00
Funder: Australian Research Council
View Funded Activity