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Sökning: WFRF:(Kamenos Nicholas A.)

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1.
  • Tuya, Fernando, et al. (författare)
  • Levelling-up rhodolith-bed science to address global-scale conservation challenges
  • 2023
  • Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 892
  • Tidskriftsartikel (refereegranskat)abstract
    • Global marine conservation remains fractured by an imbalance in research efforts and policy actions, limiting progression towards sustainability. Rhodolith beds represent a prime example, as they have ecological importance on a global scale, provide a wealth of ecosystem functions and services, including biodiversity provision and potential climate change mitigation, but remain disproportionately understudied, compared to other coastal ecosystems (tropical coral reefs, kelp forests, mangroves, seagrasses). Although rhodolith beds have gained some recognition, as important and sensitive habitats at national/regional levels during the last decade, there is still a notable lack of information and, consequently, specific conservation efforts. We argue that the lack of information about these habitats, and the significant ecosystem services they provide, is hindering the development of effective conservation measures and limiting wider marine conservation success. This is becoming a pressing issue, considering the multiple severe pressures and threats these habitats are exposed to (e.g., pollution, fishing activities, climate change), which may lead to an erosion of their ecological function and ecosystem services. By synthesizing the current knowledge, we provide arguments to highlight the importance and urgency of levelling-up research efforts focused on rhodolith beds, combating rhodolith bed degradation and avoiding the loss of associated biodiversity, thus ensuring the sustainability of future conservation programs.
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2.
  • Brodie, Juliet, et al. (författare)
  • The future of the northeast Atlantic benthic flora in a high CO2 world
  • 2014
  • Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 4:13, s. 2787-2798
  • Tidskriftsartikel (refereegranskat)abstract
    • Seaweed and seagrass communities in the northeast Atlantic have been profoundly impacted by humans, and the rate of change is accelerating rapidly due to runaway CO2 emissions and mounting pressures on coastlines associated with human population growth and increased consumption of finite resources. Here, we predict how rapid warming and acidification are likely to affect benthic flora and coastal ecosystems of the northeast Atlantic in this century, based on global evidence from the literature as interpreted by the collective knowledge of the authorship. We predict that warming will kill off kelp forests in the south and that ocean acidification will remove maerl habitat in the north. Seagrasses will proliferate, and associated epiphytes switch from calcified algae to diatoms and filamentous species. Invasive species will thrive in niches liberated by loss of native species and spread via exponential development of artificial marine structures. Combined impacts of seawater warming, ocean acidification, and increased storminess may replace structurally diverse seaweed canopies, with associated calcified and noncalcified flora, with simple habitats dominated by noncalcified, turf-forming seaweeds.
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3.
  • Burdett, Heidi L., et al. (författare)
  • Spatiotemporal Variability of Dimethylsulphoniopropionate on a Fringing Coral Reef : The Role of Reefal Carbonate Chemistry and Environmental Variability
  • 2013
  • Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Oceanic pH is projected to decrease by up to 0.5 units by 2100 (a process known as ocean acidification, OA), reducing the calcium carbonate saturation state of the oceans. The coastal ocean is expected to experience periods of even lower carbonate saturation state because of the inherent natural variability of coastal habitats. Thus, in order to accurately project the impact of OA on the coastal ocean, we must first understand its natural variability. The production of dimethylsulphoniopropionate (DMSP) by marine algae and the release of DMSP's breakdown product dimethylsulphide (DMS) are often related to environmental stress. This study investigated the spatiotemporal response of tropical macroalgae (Padina sp., Amphiroa sp. and Turbinaria sp.) and the overlying water column to natural changes in reefal carbonate chemistry. We compared macroalgal intracellular DMSP and water column DMSP+DMS concentrations between the environmentally stable reef crest and environmentally variable reef flat of the fringing Suleman Reef, Egypt, over 45-hour sampling periods. Similar diel patterns were observed throughout: maximum intracellular DMSP and water column DMS/P concentrations were observed at night, coinciding with the time of lowest carbonate saturation state. Spatially, water column DMS/P concentrations were highest over areas dominated by seagrass and macroalgae (dissolved DMS/P) and phytoplankton (particulate DMS/P) rather than corals. This research suggests that macroalgae may use DMSP to maintain metabolic function during periods of low carbonate saturation state. In the reef system, seagrass and macroalgae may be more important benthic producers of dissolved DMS/P than corals. An increase in DMS/P concentrations during periods of low carbonate saturation state may become ecologically important in the future under an OA regime, impacting larval settlement and increasing atmospheric emissions of DMS.
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4.
  • Hennige, S. J., et al. (författare)
  • Self-recognition in corals facilitates deep-sea habitat engineering
  • 2014
  • Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 4
  • Tidskriftsartikel (refereegranskat)abstract
    • The ability of coral reefs to engineer complex three-dimensional habitats is central to their success and the rich biodiversity they support. In tropical reefs, encrusting coralline algae bind together substrates and dead coral framework to make continuous reef structures, but beyond the photic zone, the cold-water coral Lophelia pertusa also forms large biogenic reefs, facilitated by skeletal fusion. Skeletal fusion in tropical corals can occur in closely related or juvenile individuals as a result of non-aggressive skeletal overgrowth or allogeneic tissue fusion, but contact reactions in many species result in mortality if there is no 'self-recognition' on a broad species level. This study reveals areas of 'flawless' skeletal fusion in Lophelia pertusa, potentially facilitated by allogeneic tissue fusion, are identified as having small aragonitic crystals or low levels of crystal organisation, and strong molecular bonding. Regardless of the mechanism, the recognition of 'self' between adjacent L. pertusa colonies leads to no observable mortality, facilitates ecosystem engineering and reduces aggression-related energetic expenditure in an environment where energy conservation is crucial. The potential for self-recognition at a species level, and subsequent skeletal fusion in framework-forming cold-water corals is an important first step in understanding their significance as ecological engineers in deep-seas worldwide.
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5.
  • Hennige, S. J., et al. (författare)
  • The potential for coral reef establishment through free-living stabilization
  • 2017
  • Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
  • Tidskriftsartikel (refereegranskat)abstract
    • Corals thrive in a variety of environments, from low wave and tidal energy lagoons, to high energy tidal reef flats, but remain dependent upon suitable substrate. Herein we reviewed the phenomenon of free-living corals (coralliths), examined whether they have the capacity to create their own stable habitat in otherwise uninhabitable, poor substrate environments through 'free-living stabilization', and explore their potential ecological role on coral reefs. This stabilization could be achieved by coral settlement and survival on mobile substrate, with subsequent growth into free-living coralliths until a critical mass is reached that prevents further movement. This allows for secondary reef colonization by other coral species. To preliminarily test this hypothesis we provide evidence that the potential to support secondary coral colonisation increases with corallith size. Due to the limited diversity of corallith species observed here and in the literature, and the lack of physiological differences exhibited by coralliths here to static controls, it seems likely that only a small selection of coral species have the ability to form coralliths, and the potential to create their own stable habitat.
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6.
  • Hennige, S. J., et al. (författare)
  • Using the Goldilocks Principle to model coral ecosystem engineering
  • 2021
  • Ingår i: Proceedings of the Royal Society B: Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 288
  • Tidskriftsartikel (refereegranskat)abstract
    • The occurrence and proliferation of reef-forming corals is of vast importance in terms of the biodiversity they support and the ecosystem services they provide. The complex three-dimensional structures engineered by corals are comprised of both live and dead coral, and the function, growth and stability of these systems will depend on the ratio of both. To model how the ratio of live: dead coral may change, the 'Goldilocks Principle' can be used, where organisms will only flourish if conditions are 'just right'. With data from particle imaging velocimetry and numerical smooth particle hydrodynamic modelling with two simple rules, we demonstrate how this principle can be applied to a model reef system, and how corals are effectively optimizing their own local flow requirements through habitat engineering. Building on advances here, these approaches can be used in conjunction with numerical modelling to investigate the growth and mortality of biodiversity supporting framework in present-day and future coral reef structures.
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7.
  • Mao, Jinhua, et al. (författare)
  • Carbon burial over the last four millennia is regulated by both climatic and land use change
  • 2020
  • Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 26:4, s. 2496-2504
  • Tidskriftsartikel (refereegranskat)abstract
    • Carbon sequestration by sediments and vegetated marine systems contributes to atmospheric carbon drawdown, but little empirical evidence is available to help separate the effects of climate change and other anthropogenic activities on carbon burial over centennial timescales. We used marine sediment organic carbon to determine the role of historic climate variability and human habitation in carbon burial over the past 5,071 years. There was centennial-scale sensitivity of carbon supply and burial to climatic variability, with Little Ice Age cooling causing an abrupt ecosystem shift and an increase in marine carbon contributions compared to terrestrial carbon. Although land use changes during the late 1800s did not cause marked alteration in average carbon burial, they did lead to marked increases in the spatial variability of carbon burial. Thus, while carbon burial by vegetated systems is expected to increase with projected climate warming over the coming century, ecosystem restructuring caused by abrupt climate change may produce unexpected change in carbon burial whose variability is also modulated by land use change.
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8.
  • McCoy, Sophie J., et al. (författare)
  • A mineralogical record of ocean change : Decadal and centennial patterns in the California mussel
  • 2018
  • Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 24:6, s. 2554-2562
  • Tidskriftsartikel (refereegranskat)abstract
    • Ocean acidification, a product of increasing atmospheric carbon dioxide, may already have affected calcified organisms in the coastal zone, such as bivalves and other shellfish. Understanding species' responses to climate change requires the context of long-term dynamics. This can be particularly difficult given the longevity of many important species in contrast with the relatively rapid onset of environmental changes. Here, we present a unique archival dataset of mussel shells from a locale with recent environmental monitoring and historical climate reconstructions. We compare shell structure and composition in modern mussels, mussels from the 1970s, and mussel shells dating back to 1000-2420 years BP. Shell mineralogy has changed dramatically over the past 15 years, despite evidence for consistent mineral structure in the California mussel, Mytilus californianus, over the prior 2500 years. We present evidence for increased disorder in the calcium carbonate shells of mussels and greater variability between individuals. These changes in the last decade contrast markedly from a background of consistent shell mineralogy for centuries. Our results use an archival record of natural specimens to provide centennial-scale context for altered minerology and variability in shell features as a response to acidification stress and illustrate the utility of long-term studies and archival records in global change ecology. Increased variability between individuals is an emerging pattern in climate change responses, which may equally expose the vulnerability of organisms and the potential of populations for resilience.
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9.
  • Rasher, Douglas B., et al. (författare)
  • Keystone predators govern the pathway and pace of climate impacts in a subarctic marine ecosystem
  • 2020
  • Ingår i: Science. - : American Association for the Advancement of Science. - 0036-8075 .- 1095-9203. ; 369:6509, s. 1351-1355
  • Tidskriftsartikel (refereegranskat)abstract
    • Predator loss and climate change are hallmarks of the Anthropocene yet their interactive effects are largely unknown. Here, we show that massive calcareous reefs, built slowly by the alga Clathromorphum nereostratum over centuries to millennia, are now declining because of the emerging interplay between these two processes. Such reefs, the structural base of Aleutian kelp forests, are rapidly eroding because of overgrazing by herbivores. Historical reconstructions and experiments reveal that overgrazing was initiated by the loss of sea otters, Enhydra lutris (which gave rise to herbivores capable of causing bioerosion), and then accelerated with ocean warming and acidification (which increased per capita lethal grazing by 34 to 60% compared with preindustrial times). Thus, keystone predators can mediate the ways in which climate effects emerge in nature and the pace with which they alter ecosystems.
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10.
  • Recknagel, Hans, et al. (författare)
  • The functional genetic architecture of egg-laying and live-bearing reproduction in common lizards
  • 2021
  • Ingår i: Nature Ecology & Evolution. - : Springer Nature. - 2397-334X. ; 5:11, s. 1546-1556
  • Tidskriftsartikel (refereegranskat)abstract
    • All amniotes reproduce either by egg-laying (oviparity), which is ancestral to vertebrates or by live-bearing (viviparity), which has evolved many times independently. However, the genetic basis of these parity modes has never been resolved and, consequently, its convergence across evolutionary scales is currently unknown. Here, we leveraged natural hybridizations between oviparous and viviparous common lizards (Zootoca vivipara) to describe the functional genes and genetic architecture of parity mode and its key traits, eggshell and gestation length, and compared our findings across vertebrates. In these lizards, parity trait genes were associated with progesterone-binding functions and enriched for tissue remodelling and immune system pathways. Viviparity involved more genes and complex gene networks than did oviparity. Angiogenesis, vascular endothelial growth and adrenoreceptor pathways were enriched in the viviparous female reproductive tissue, while pathways for transforming growth factor were enriched in the oviparous. Natural selection on these parity mode genes was evident genome-wide. Our comparison to seven independent origins of viviparity in mammals, squamates and fish showed that genes active in pregnancy were related to immunity, tissue remodelling and blood vessel generation. Therefore, our results suggest that pre-established regulatory networks are repeatedly recruited for viviparity and that these are shared at deep evolutionary scales. Using natural hybrids between oviparous and viviparous common lizards, the authors describe the genetic architecture of parity mode and conduct a comparative analysis of genes associated with viviparity in mammals, squamates and fish.
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11.
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12.
  • Attard, Karl M., et al. (författare)
  • Benthic oxygen exchange in a live coralline algal bed and an adjacent sandy habitat : an eddy covariance study
  • 2015
  • Ingår i: Marine Ecology Progress Series. - : Inter-Research. - 0171-8630 .- 1616-1599. ; 535, s. 99-115
  • Tidskriftsartikel (refereegranskat)abstract
    • Coralline algal (maerl) beds are widespread, slow-growing, structurally complex perennial habitats that support high biodiversity, yet are significantly understudied compared to seagrass beds or kelp forests. We present the first eddy covariance (EC) study on a live maerl bed, assessing the community benthic gross primary productivity (GPP), respiration (R), and net ecosystem metabolism (NEM) derived from diel EC time series collected during 5 seasonal measurement campaigns in temperate Loch Sween, Scotland. Measurements were also carried out at an adjacent (similar to 20 m distant) permeable sandy habitat. The O-2 exchange rate was highly dynamic, driven by light availability and the ambient tidally-driven flow velocity. Linear relationships between the EC O-2 fluxes and available light indicate that the benthic phototrophic communities were light limited. Compensation irradiance (E-c) varied seasonally and was typically similar to 1.8-fold lower at the maerl bed compared to the sand. Substantial GPP was evident at both sites; however, the maerl bed and the sand habitat were net heterotrophic during each sampling campaign. Additional inputs of similar to 4 and similar to 7 mol m(-2) yr(-1) of carbon at the maerl bed and sand site, respectively, were required to sustain the benthic O-2 demand. Thus, the 2 benthic habitats efficiently entrap organic carbon and are sinks of organic material in the coastal zone. Parallel deployment of 0.1 m(2) benthic chambers during nighttime revealed O-2 uptake rates that varied by up to similar to 8-fold between replicate chambers (from -0.4 to -3.0 mmol O-2 m(-2) h(-1); n = 4). However, despite extensive O-2 flux variability on meter horizontal scales, mean rates of O-2 uptake as resolved in parallel by chambers and EC were typically within 20% of one another.
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13.
  • Bach, Lydia L., et al. (författare)
  • In situ Response of Tropical Coralline Algae to a Novel Thermal Regime
  • 2017
  • Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 4
  • Tidskriftsartikel (refereegranskat)abstract
    • Coralline algae provide important ecosystem services. In situ observations of how they respond to different environmental conditions can help us to understand (i) their ability to adapt to their local environment and (0 their capacity to acclimatize to a novel thermal regime. Here, individuals of the tropical coralline algae, Lithophyllum kotschyanum, were translocated on a coral reef from thermally stable areas to areas characterized by natural temperature variability. Changes in their photosynthetic efficiency were determined using pulse amplitude modulation (PAM) chlorophyll fluorescence. Despite an initial stress response, algae exposed to increases in thermal variation recovered within 24 hours, indicating a rapid, short-term acclimatization capacity. Algae naturally inhabiting thermally variable areas of the reef showed no change in photosynthetic efficiency throughout the study suggesting longer-term adaptation to living in a variable environment also occurs. However, coralline algae living in thermally stable reef areas were abundant and marginally larger, suggesting physiological trade-offs are used to survive in variable environments. Thus, our results suggest that while coralline algae can survive in environmentally variable conditions, there may be structural and ecosystem costs.
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14.
  • Burdett, Heidi L., et al. (författare)
  • Community-level sensitivity of a calcifying ecosystem to acute in situ CO2 enrichment
  • 2018
  • Ingår i: Marine Ecology Progress Series. - : Inter-Research. - 0171-8630 .- 1616-1599. ; 587, s. 73-80
  • Tidskriftsartikel (refereegranskat)abstract
    • The rate of change in ocean carbonate chemistry is a vital determinant in the magnitude of effects observed. Benthic marine ecosystems are facing an increasing risk of acute CO2 exposure that may be natural or anthropogenically derived (e.g. engineering and industrial activities). However, our understanding of how acute CO2 events impact marine life is restricted to individual organisms, with little understanding for how this manifests at the community level. Here, we investigated in situ the effect of acute CO2 enrichment on the coralline algal ecosystem - a globally ubiquitous, ecologically and economically important habitat, but one which is likely to be sensitive to CO2 enrichment due to its highly calcified reef-like structures engineered by coralline algae. Most notably, we observed a rapid community-level shift to favour net dissolution rather than net calcification. Smaller changes from net respiration to net photosynthesis were also observed. There was no effect on the net flux of DMS/DMSP (algal secondary metabolites), nor on the nutrients nitrate and phosphate. Following return to ambient CO2 levels, only a partial recovery was seen within the monitoring timeframe. This study highlights the sensitivity of biogenic carbonate marine communities to acute CO2 enrichment and raises concerns over the capacity for the system to 'bounce back' if subjected to repeated acute high-CO2 events.
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15.
  • Burdett, Heidi L., et al. (författare)
  • Coralline algae as a globally significant pool of marine dimethylated sulfur
  • 2015
  • Ingår i: Global Biogeochemical Cycles. - : Blackwell Publishing. - 0886-6236 .- 1944-9224. ; 29:10, s. 1845-1853
  • Tidskriftsartikel (refereegranskat)abstract
    • Marine algae are key sources of the biogenic sulfur compound dimethylsulphoniopropionate (DMSP), a vital component of the marine sulfur cycle. Autotrophic ecosystem engineers such as red coralline algae support highly diverse and biogeochemically active ecosystems and are known to be high DMSP producers, but their importance in the global marine sulfur cycle has not yet been appreciated. Using a global sampling approach, we show that red coralline algae are a globally significant pool of DMSP in the oceans, estimated to be similar to 110x10(12) moles worldwide during the summer months. Latitude was a major driver of observed regional-scale variations, with peaks in polar and tropical climate regimes, reflecting the varied cellular functions for DMSP (e.g., as a cryoprotectant and antioxidant). A temperate coralline algal bed was investigated in more detail to also identify local-scale temporal variations. Here, water column DMSP was driven by water temperature, and to a lesser extent, cloud cover; two factors which are also vital in controlling coralline algal growth. This study demonstrates that coralline algae harbor a large pool of dimethylated sulfur, thereby playing a significant role in both the sulfur and carbon marine biogeochemical cycles. However, coralline algal habitats are severely threatened by projected climate change; a loss of this habitat may thus detrimentally impact oceanic sulfur and carbon biogeochemical cycling.
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16.
  • Burdett, Heidi L., et al. (författare)
  • Dynamic photoinhibition exhibited by red coralline algae in the red sea
  • 2014
  • Ingår i: BMC Plant Biology. - : BioMed Central. - 1471-2229. ; 14
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Red coralline algae are critical components of tropical reef systems, and their success and development is, at least in part, dependent on photosynthesis. However, natural variability in the photosynthetic characteristics of red coralline algae is poorly understood. This study investigated diurnal variability in encrusting Porolithon sp. and free-living Lithophyllum kotschyanum. Measured parameters included: photosynthetic characteristics, pigment composition, thallus reflectance and intracellular concentrations of dimethylsulphoniopropionate (DMSP), an algal antioxidant that is derived from methionine, an indirect product of photosynthesis. L. kotschyanum thalli were characterised by a bleached topside and a pigmented underside.Results: Minimum saturation intensity and intracellular DMSP concentrations in Porolithon sp. were characterised by significant diurnal patterns in response to the high-light regime. A smaller diurnal pattern in minimum saturation intensity in the topside of L. kotschyanum was also evident. The overall reflectance of the topside of L. kotschyanum also exhibited a diurnal pattern, becoming increasingly reflective with increasing ambient irradiance. The underside of L. kotschyanum, which is shaded from ambient light exposure, exhibited a much smaller diurnal variability.Conclusions: This study highlights a number of dynamic photoinhibition strategies adopted by coralline algae, enabling them to tolerate, rather than be inhibited by, the naturally high irradiance of tropical reef systems; a factor that may become more important in the future under global change projections. In this context, this research has significant implications for tropical reef management planning and conservation monitoring, which, if natural variability is not taken into account, may become flawed. The information provided by this research may be used to inform future investigations into the contribution of coralline algae to reef accretion, ecosystem service provision and palaeoenvironmental reconstruction.
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17.
  • Burdett, H. L., et al. (författare)
  • Effects of high temperature and CO2 on intracellular DMSP in the cold-water coral Lophelia pertusa
  • 2014
  • Ingår i: Marine Biology. - : Springer. - 0025-3162 .- 1432-1793. ; 161:7, s. 1499-1506
  • Tidskriftsartikel (refereegranskat)abstract
    • Significant warming and acidification of the oceans is projected to occur by the end of the century. CO2 vents, areas of upwelling and downwelling, and potential leaks from carbon capture and storage facilities may also cause localised environmental changes, enhancing or depressing the effect of global climate change. Cold-water coral ecosystems are threatened by future changes in carbonate chemistry, yet our knowledge of the response of these corals to high temperature and high CO2 conditions is limited. Dimethylsulphoniopropionate (DMSP), and its breakdown product dimethylsulphide (DMS), are putative antioxidants that may be accumulated by invertebrates via their food or symbionts, although recent research suggests that some invertebrates may also be able to synthesise DMSP. This study provides the first information on the impact of high temperature (12 A degrees C) and high CO2 (817 ppm) on intracellular DMSP in the cold-water coral Lophelia pertusa from the Mingulay Reef Complex, Scotland (56A degrees 49'N, 07A degrees 23'W), where in situ environmental conditions are meditated by tidally induced downwellings. An increase in intracellular DMSP under high CO2 conditions was observed, whilst water column particulate DMS + DMSP was reduced. In both high temperature treatments, intracellular DMSP was similar to the control treatment, whilst dissolved DMSP + DMS was not significantly different between any of the treatments. These results suggest that L. pertusa accumulates DMSP from the surrounding water column; uptake may be up-regulated under high CO2 conditions, but mediated by high temperature. These results provide new insight into the biotic control of deep-sea biogeochemistry and may impact our understanding of the global sulphur cycle, and the survival of cold-water corals under projected global change.
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18.
  • Burdett, Heidi L., et al. (författare)
  • Effects of reduced salinity on the photosynthetic characteristics and intracellular DMSP concentrations of the red coralline alga, Lithothamnion glaciale
  • 2015
  • Ingår i: Marine Biology. - : Springer. - 0025-3162 .- 1432-1793. ; 162:5, s. 1077-1085
  • Tidskriftsartikel (refereegranskat)abstract
    • Mid- to high-latitude fjordic coastal environments experience naturally variable salinity regimes. Climate projections suggest that freshwater input into the coastal ocean will increase in the future, exposing coastal organisms to further periods of reduced salinity. This study investigated the effect of low salinity on Lithothamnion glaciale, a red coralline alga found in mid- to high-latitude fjordic regions, during a 21-day experiment. Specific measurements included: the intracellular concentration of dimethylsulphoniopropionate (DMSP, an algal secondary metabolite and major precursor to the climatically active gas dimethylsulphide), pigment composition and photosynthetic characteristics. No significant difference in intracellular DMSP concentrations was observed between treatments, suggesting that the primary function for DMSP in L. glaciale is not as a compatible solute, perhaps favouring an antioxidant role . Photosynthetic parameters (including pigment composition) exhibited a mixed response, suggesting some degree of photosynthetic resilience to reduced salinity. This study provides evidence of intracellular mechanisms adopted by L. glaciale in response to reduced salinity. This has significant implications for the survival of L. glaciale under a projected freshening scenario and provides organism-level detail to ecosystem-level projected changes should lower-salinity conditions become more frequent and more intense in the future.
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19.
  • Burdett, Heidi L., et al. (författare)
  • Including environmental and climatic considerations for sustainable coral reef restoration
  • 2024
  • Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 22:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Coral reefs provide ecosystem benefits to millions of people but are threatened by rapid environmental change and ever-increasing human pressures. Restoration is becoming a priority strategy for coral reef conservation, yet implementation remains challenging and it is becoming increasingly apparent that indirect conservation and restoration approaches will not ensure the long-term sustainability of coral reefs. The important role of environmental conditions in restoration practice are currently undervalued, carrying substantial implications for restoration success. Giving paramount importance to environmental conditions, particularly during the pre-restoration planning phase, has the potential to bring about considerable improvements in coral reef restoration and innovation. This Essay argues that restoration risk may be reduced by adopting an environmentally aware perspective that gives historical, contemporary, and future context to restoration decisions. Such an approach will open up new restoration opportunities with improved sustainability that have the capacity to dynamically respond to environmental trajectories.
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20.
  • Burdett, Heidi L., et al. (författare)
  • The effect of chronic and acute low pH on the intracellular DMSP production and epithelial cell morphology of red coralline algae
  • 2012
  • Ingår i: Marine Biology Research. - : Taylor & Francis. - 1745-1000 .- 1745-1019. ; 8:8, s. 756-763
  • Tidskriftsartikel (refereegranskat)abstract
    • The release of dimethylsulphoniopropionate (DMSP) by marine algae has major impacts on the global sulphur cycle and may influence local climate through the formation of dimethylsulphide (DMS). However, the effect of global change on DMSP/DMS (DMS(P)) production by algae is not well understood. This study examined the effect of low pH on DMS(P) production and epithelial cell morphology of the free-living red coralline alga Lithothamnion glaciale. Three pH treatments were used in the 80-day experiment: (1) current pH level (8.18, control), (2) low, chronic pH representing a 2100 ocean acidification (OA) scenario (7.70) and (3) low, acute pH (7.75, with a 3-day spike to 6.47), representing acute variable conditions that might be associated with leaks from carbon capture and storage infrastructure, at CO2 vent sites or in areas of upwelling. DMS(P) production was not significantly enhanced under low, stable pH conditions, indicating that red coralline algae may have some resilience to OA. However, intracellular and water column DMS(P) concentrations were significantly higher than the control when pH was acutely spiked. Cracks were observed between the cell walls of the algal skeleton in both low pH treatments. It is proposed that this structural change may cause membrane damage that allows DMS(P) to leak from the cells into the water column, with subsequent implications for the cycling of DMS(P) in coralline algae habitats.
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21.
  • Burdett, Heidi L., et al. (författare)
  • The photosynthetic characteristics of red coralline algae, determined using pulse amplitude modulation (PAM) fluorometry
  • 2012
  • Ingår i: Botanica Marina. - : Walter de Gruyter. - 0006-8055 .- 1437-4323. ; 55:5, s. 499-509
  • Tidskriftsartikel (refereegranskat)abstract
    • Interest in red coralline algae is increasing due to their projected sensitivity to ocean acidification and their utility as palaeoenvironmental proxies. Thus, it is crucial to obtain a thorough understanding of their basic photosynthetic characteristics and appropriate techniques for use in both laboratory and in situ studies. This study provides fluorescence methodology and data for the ecologically important red coralline alga Lithothamnion glaciale using pulse amplitude modulation (PAM) fluorometry. Lithothamnion glaciale was sufficiently dark-acclimated for in situ work following 10 s of quasi-darkness, attaining 95-98% of the maximum photochemical efficiency (F-v/F-m). Rapid light curves conducted in situ and in the laboratory determined a low light adaptation, with a saturation intensity of 4.45-54.6 mu mol photons m(-2)s(-1). Intra-thallus heterogeneity was observed between branch tips and bases (i.e., within the thallus) using a custom-made 2 mm fibre optic probe (the heterogeneity could not be detected using the standard 5 mm probe). Branch bases were lower light acclimated than the tips, with higher maximum effective quantum yield (F-q'/F-m'(max)) and lower non-photochemical quenching. Samples measured in May were higher light acclimated than in March, which suggests a degree of seasonal acclimation. Light history and photon irradiance levels were thus found to significantly affect the photosynthetic characteristics of L. glaciale
  •  
22.
  • Burdett, Heidi, et al. (författare)
  • Using coralline algae to understand historic marine cloud cover
  • 2011
  • Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier. - 0031-0182 .- 1872-616X. ; 302:1-2, s. 65-70
  • Tidskriftsartikel (refereegranskat)abstract
    • Free-living coralline algae lay down growth bands formed by areas of more and less calcified cells which, in certain species, are associated with winter and summer growth respectively. Band width and cell calcification of Lithothamnion glaciale from Scotland were compared to annual and seasonal cloud cover and sea surface temperature (SST). There was a negative relationship between summer calcification (the degree of cellular carbonate infilling) and winter cloud cover. Annual and summer SST were also negatively related to summer calcification. This indicates that summer calcification may be affected by the previous winter's cloud cover and that summer's/year's SST. No relationships between band width and cloud cover were observed. A cloud cover hindcast using summer calcification and SST indicated a modest rise in cloud cover trends from 1910 to 2006 and a 12 (mean) year cyclicity in cloud cover, however, the latter may be associated with other site-specific factors. This study demonstrates the utility of densitometric algochronology in understanding marine temperature and cloud cover histories. 
  •  
23.
  • Claverie, Thomas, et al. (författare)
  • Spawning aggregations and mass movements in subtidal Onchidoris bilamellata (Mollusca Opisthobranchia)
  • 2008
  • Ingår i: Journal of the Marine Biological Association of the United Kingdom. - : Cambridge University Press. - 0025-3154 .- 1469-7769. ; 88:1, s. 157-159
  • Tidskriftsartikel (refereegranskat)abstract
    • Little is known about spawning aggregations in subtidal populations of the nudibranch Onchidoris bilamellata. We provide photographic evidence of the spawning aggregations and associated spawning migrations or mass movements whose occurrence was debated.
  •  
24.
  • Cusack, Maggie, et al. (författare)
  • Biomineral repair of abalone shell apertures
  • 2013
  • Ingår i: Journal of Structural Biology. - : Elsevier. - 1047-8477 .- 1095-8657. ; 183:2, s. 165-171
  • Tidskriftsartikel (refereegranskat)abstract
    • The shell of the gastropod mollusc, abalone, is comprised of nacre with an outer prismatic layer that is composed of either calcite or aragonite or both, depending on the species. A striking characteristic of the abalone shell is the row of apertures along the dorsal margin. As the organism and shell grow, new apertures are formed and the preceding ones are filled in. Detailed investigations, using electron backscatter diffraction, of the infill in three species of abalone: Haliotis asinina, Haliotis gigantea and Haliotis rufescens reveals that, like the shell, the infill is composed mainly of nacre with an outer prismatic layer. The infill prismatic layer has identical mineralogy as the original shell prismatic layer. In H. asinina and H. gigantea, the prismatic layer of the shell and infill are made of aragonite while in H. rufescens both are composed of calcite. Abalone builds the infill material with the same high level of biological control, replicating the structure, mineralogy and crystallographic orientation as for the shell. The infill of abalone apertures presents us with insight into what is, effectively, shell repair. 
  •  
25.
  • Cusack, M., et al. (författare)
  • Red coralline algae assessed as marine pH proxies using B-11 MAS NMR
  • 2015
  • Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 5
  • Tidskriftsartikel (refereegranskat)abstract
    • Reconstructing pH from biogenic carbonates using boron isotopic compositions relies on the assumption that only borate, and no boric acid, is present. Red coralline algae are frequently used in palaeoenvironmental reconstruction due to their widespread distribution and regular banding frequency. Prior to undertaking pH reconstructions using red coralline algae we tested the boron composition of the red coralline alga Lithothamnion glaciale using high field NMR. In bulk analysed samples, thirty percent of boron was present as boric acid. We suggest that prior to reconstructing pH using coralline algae 1) species-specific boron compositions and 2) within-skeleton special distributions of boron are determined for multiple species. This will enable site selective boron analyses to be conducted validating coralline algae as palaeo-pH proxies based on boron isotopic compositions.
  •  
26.
  • Downie, J. R., et al. (författare)
  • Are there costs to extended larval transport in the Trinidadian stream frog, Mannophryne trinitatis (Dendrobatidae)?
  • 2005
  • Ingår i: Journal of Natural History. - : Taylor & Francis. - 0022-2933 .- 1464-5262. ; 39:22, s. 2023-2034
  • Tidskriftsartikel (refereegranskat)abstract
    • Previous work has shown that male Mannophryne trinitatis (Dendrobatidae) carry their larvae on their backs for up to 4 days in search of a predator-free pool in which to deposit them. The experiments reported here investigated whether costs to the larvae or to the adults limit transport duration. We simulated transport durations of 0, 4, 8, and 12 days for larvae, but found no deterioration in terms of ability to grow to metamorphosis; indeed, 12-day larvae grew better than all the others. After 8 days of simulated transport, larvae had used up all their yolk reserves and begun to lose dry weight. Larvae on wet substrates gained wet weight and length but on drier substrates merely maintained weight, suggesting that dehydration could be a problem on the male's back. In a trial of locomotor performance ( mean jump length; number of jumps to traverse a runway), females performed best with calling males not significantly different from transporting males, despite an average larval load equivalent to 15-20% of the frog's mass. Assessment of gut contents showed that females foraged more than males, but that transporting males foraged as much as did calling males. We found no differences between the three classes of adult frogs in fat body weight.
  •  
27.
  • Fitzer, Susan C., et al. (författare)
  • Biomineral shell formation under ocean acidification : a shift from order to chaos
  • 2016
  • Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 6
  • Tidskriftsartikel (refereegranskat)abstract
    • Biomineral production in marine organisms employs transient phases of amorphous calcium carbonate (ACC) in the construction of crystalline shells. Increasing seawater pCO(2) leads to ocean acidification (OA) with a reduction in oceanic carbonate concentration which could have a negative impact on shell formation and therefore survival. We demonstrate significant changes in the hydrated and dehydrated forms of ACC in the aragonite and calcite layers of Mytilus edulis shells cultured under acidification conditions (1000 mu atm pCO(2)) compared to present day conditions (380 mu atm pCO(2)). In OA conditions, Mytilus edulis has more ACC at crystalisation sites. Here, we use the high-spatial resolution of synchrotron X-ray Photo Emission Electron Microscopy (XPEEM) combined with X-ray Absorption Spectroscopy (XAS) to investigate the influence of OA on the ACC formation in the shells of adult Mytilus edulis. Electron Backscatter Diffraction (EBSD) confirms that OA reduces crystallographic control of shell formation. The results demonstrate that OA induces more ACC formation and less crystallographic control in mussels suggesting that ACC is used as a repair mechanism to combat shell damage under OA. However, the resultant reduced crystallographic control in mussels raises concerns for shell protective function under predation and changing environments.
  •  
28.
  • Fitzer, Susan C., et al. (författare)
  • Ocean acidification alters the material properties of Mytilus edulis shells
  • 2015
  • Ingår i: Journal of the Royal Society Interface. - : Royal Society Publishing. - 1742-5689 .- 1742-5662. ; 12:103
  • Tidskriftsartikel (refereegranskat)abstract
    • Ocean acidification (OA) and the resultant changing carbonate saturation states is threatening the formation of calcium carbonate shells and exoskeletons of marine organisms. The production of biominerals in such organisms relies on the availability of carbonate and the ability of the organism to biomineralize in changing environments. To understand how biomineralizers will respond to OA the common blue mussel, Mytilus edulis, was cultured at projected levels of pCO(2) (380, 550, 750, 1000 mu atm) and increased temperatures (ambient, ambient plus 2 degrees C). Nanoindentation (a single mussel shell) and microhardness testing were used to assess the material properties of the shells. Young's modulus (E), hardness (H) and toughness (K-IC) were measured in mussel shells grown in multiple stressor conditions. OA caused mussels to produce shell calcite that is stiffer (higher modulus of elasticity) and harder than shells grown in control conditions. The outer shell (calcite) is more brittle in OA conditions while the inner shell (aragonite) is softer and less stiff in shells grown under OA conditions. Combining increasing ocean pCO(2) and temperatures as projected for future global ocean appears to reduce the impact of increasing pCO(2) on the material properties of the mussel shell. OA may cause changes in shell material properties that could prove problematic under predation scenarios for the mussels; however, this may be partially mitigated by increasing temperature.
  •  
29.
  • Fitzer, Susan C., et al. (författare)
  • Ocean acidification and temperature increase impact mussel shell shape and thickness : problematic for protection?
  • 2015
  • Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 5:21, s. 4875-4884
  • Tidskriftsartikel (refereegranskat)abstract
    • Ocean acidification threatens organisms that produce calcium carbonate shells by potentially generating an under-saturated carbonate environment. Resultant reduced calcification and growth, and subsequent dissolution of exoskeletons, would raise concerns over the ability of the shell to provide protection for the marine organism under ocean acidification and increased temperatures. We examined the impact of combined ocean acidification and temperature increase on shell formation of the economically important edible mussel Mytilus edulis. Shell growth and thickness along with a shell thickness index and shape analysis were determined. The ability of M.edulis to produce a functional protective shell after 9months of experimental culture under ocean acidification and increasing temperatures (380, 550, 750, 1000atm pCO(2), and 750, 1000atm pCO(2)+2 degrees C) was assessed. Mussel shells grown under ocean acidification conditions displayed significant reductions in shell aragonite thickness, shell thickness index, and changes to shell shape (750, 1000atm pCO(2)) compared to those shells grown under ambient conditions (380atm pCO(2)). Ocean acidification resulted in rounder, flatter mussel shells with thinner aragonite layers likely to be more vulnerable to fracture under changing environments and predation. The changes in shape presented here could present a compensatory mechanism to enhance protection against predators and changing environments under ocean acidification when mussels are unable to grow thicker shells. Here, we present the first assessment of mussel shell shape to determine implications for functional protection under ocean acidification.
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30.
  • Fitzer, Susan C., et al. (författare)
  • Ocean acidification impacts mussel control on biomineralisation
  • 2014
  • Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 4
  • Tidskriftsartikel (refereegranskat)abstract
    • Ocean acidification is altering the oceanic carbonate saturation state and threatening the survival of marine calcifying organisms. Production of their calcium carbonate exoskeletons is dependent not only on the environmental seawater carbonate chemistry but also the ability to produce biominerals through proteins. We present shell growth and structural responses by the economically important marine calcifier Mytilus edulis to ocean acidification scenarios (380, 550, 750, 1000 mu atm pCO(2)). After six months of incubation at 750 matm pCO(2), reduced carbonic anhydrase protein activity and shell growth occurs in M. edulis. Beyond that, at 1000 matm pCO(2), biomineralisation continued but with compensated metabolism of proteins and increased calcite growth. Mussel growth occurs at a cost to the structural integrity of the shell due to structural disorientation of calcite crystals. This loss of structural integrity could impact mussel shell strength and reduce protection from predators and changing environments.
  •  
31.
  • Fitzer, Susan C., et al. (författare)
  • Ocean acidification reduces the crystallographic control in juvenile mussel shells
  • 2014
  • Ingår i: Journal of Structural Biology. - : Elsevier. - 1047-8477 .- 1095-8657. ; 188:1, s. 39-45
  • Tidskriftsartikel (refereegranskat)abstract
    • Global climate change threatens the oceans as anthropogenic carbon dioxide causes ocean acidification and reduced carbonate saturation. Future projections indicate under saturation of aragonite, and potentially calcite, in the oceans by 2100. Calcifying organisms are those most at risk from such ocean acidification, as carbonate is vital in the biomineralisation of their calcium carbonate protective shells. This study highlights the importance of multi-generational studies to investigate how marine organisms can potentially adapt to future projected global climate change. Mytilus edulis is an economically important marine calcifier vulnerable to decreasing carbonate saturation as their shells comprise two calcium carbonate polymorphs: aragonite and calcite. M. edulis specimens were cultured under current and projected pCO(2) (380, 550, 750 and 1000 mu atm), following 6 months of experimental culture, adults produced second generation juvenile mussels. juvenile mussel shells were examined for structural and crystallographic orientation of aragonite and calcite. At 1000 mu atm pCO(2), juvenile mussels spawned and grown under this high pCO(2) do not produce aragonite which is more vulnerable to carbonate under-saturation than calcite. Calcite and aragonite were produced at 380, 550 and 750 mu atm pCO(2). Electron back scatter diffraction analyses reveal less constraint in crystallographic orientation with increased pCO(2). Shell formation is maintained, although the nacre crystals appear corroded and crystals are not so closely layered together. The differences in ultrastructure and crystallography in shells formed by juveniles spawned from adults in high pCO(2) conditions may prove instrumental in their ability to survive ocean acidification. 
  •  
32.
  • Hennige, Sebastian J., et al. (författare)
  • Crumbling Reefs and Cold-Water Coral Habitat Loss in a Future Ocean : Evidence of "Coralporosis" as an Indicator of Habitat Integrity
  • 2020
  • Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 7
  • Tidskriftsartikel (refereegranskat)abstract
    • Ocean acidification is a threat to the net growth of tropical and deep-sea coral reefs, due to gradual changes in the balance between reef growth and loss processes. Here we go beyond identification of coral dissolution induced by ocean acidification and identify a mechanism that will lead to a loss of habitat in cold-water coral reef habitats on an ecosystem-scale. To quantify this, we present in situ and year-long laboratory evidence detailing the type of habitat shift that can be expected (in situ evidence), the mechanisms underlying this (in situ and laboratory evidence), and the timescale within which the process begins (laboratory evidence). Through application of engineering principals, we detail how increased porosity in structurally critical sections of coral framework will lead to crumbling of load-bearing material, and a potential collapse and loss of complexity of the larger habitat. Importantly, in situ evidence highlights that cold-water corals can survive beneath the aragonite saturation horizon, but in a fundamentally different way to what is currently considered a biogenic cold-water coral reef, with a loss of the majority of reef habitat. The shift from a habitat with high 3-dimensional complexity provided by both live and dead coral framework, to a habitat restricted primarily to live coral colonies with lower 3-dimensional complexity represents the main threat to cold-water coral reefs of the future and the biodiversity they support. Ocean acidification can cause ecosystem-scale habitat loss for the majority of cold-water coral reefs.
  •  
33.
  • Hennige, S. J., et al. (författare)
  • Hidden impacts of ocean acidification to live and dead coral framework
  • 2015
  • Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : Royal Society Publishing. - 0962-8452 .- 1471-2954. ; 282:1813
  • Tidskriftsartikel (refereegranskat)abstract
    • Cold-water corals, such as Lophelia pertusa, are key habitat-forming organisms found throughout the world's oceans to 3000 m deep. The complex three-dimensional framework made by these vulnerable marine ecosystems support high biodiversity and commercially important species. Given their importance, a key question is how both the living and the dead framework will fare under projected climate change. Here, we demonstrate that over 12 months L. pertusa can physiologically acclimate to increased CO2, showing sustained net calcification. However, their new skeletal structure changes and exhibits decreased crystallographic and molecular-scale bonding organization. Although physiological acclimatization was evident, we also demonstrate that there is a negative correlation between increasing CO2 levels and breaking strength of exposed framework (approx. 20-30% weaker after 12 months), meaning the exposed bases of reefs will be less effective load-bearers', and will become more susceptible to bioerosion and mechanical damage by 2100.
  •  
34.
  • Hennige, S. J., et al. (författare)
  • Short-term metabolic and growth responses of the cold-water coral Lophelia pertusa to ocean acidification
  • 2014
  • Ingår i: Deep-sea research. Part II, Topical studies in oceanography. - : Elsevier BV. - 0967-0645 .- 1879-0100. ; 99, s. 27-35
  • Tidskriftsartikel (refereegranskat)abstract
    • Cold-water corals are associated with high local biodiversity, but despite their importance as ecosystem engineers, little is known about how these organisms will respond to projected ocean acidification. Since preindustrial times, average ocean pH has decreased from 8.2 to similar to 8.1, and predicted CO2 emissions will decrease by up to another 0.3 pH units by the end of the century. This decrease in pH may have a wide range of impacts upon marine life, and in particular upon calcifiers such as cold-water corals. Lophelia pertusa is the most widespread cold-water coral (CWC) species, frequently found in the North Atlantic. Here, we present the first short-term (21 days) data on the effects of increased CO2 (750 ppm) upon the metabolism of freshly collected L pertusa from Mingulay Reef Complex, Scotland, for comparison with net calcification. Over 21 days, corals exposed to increased CO2 conditions had significantly lower respiration rates (11.4 +/- 1.39 SE, gmol O-2 g(-1) tissue dry weight h(-1)) than corals in control conditions (28.6 +/- 7.30 SE mu mol O-2 g(-1) tissue dry weight h(-1)). There was no corresponding change in calcification rates between treatments, measured using the alkalinity anomaly technique and C-14 uptake. The decrease in respiration rate and maintenance of calcification rate indicates an energetic imbalance, likely facilitated by utilisation of lipid reserves. These data from freshly collected L pertusa from the Mingulay Reef Complex will help define the impact of ocean acidification upon the growth, physiology and structural integrity of this key reef framework forming species. 
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35.
  •  
36.
  • Jackson, C M, et al. (författare)
  • Meiofaunal bivalves in maerl and other substrata; Their diversity and community structure
  • 2004
  • Ingår i: Ophelia. - Stenstrup : Ophelia Publications. - 0078-5326. ; 58:1, s. 49-60
  • Tidskriftsartikel (refereegranskat)abstract
    • The abundance and diversity of meiofaunal bivalve species from four substrata (live maerl, dead maerl, gravel and sand) were investigated to assess the effects of habitat heterogeneity. Maerl grounds are unusual coastal habitats derived of non-geniculate coralline algae (Corallmaceae, Rhodophyta) and typically exhibit high benthic biodiversity, including a large number of molluscan species. In total 38 species of bivalves were recorded, with the greatest number found in dead maerl (29). These results were contrary to the findings of other authors who have shown dead maerl grounds to have a poorer fauna than live maerl beds. Significant differences were observed in the community structure of the substrata examined, with assemblages on sand being easily distinguishable from those on other substrata. Mysella bidentata was found to be an important species in dead maerl and gravel. In sand the tellinids Moerella pygmaea and Angulus tenuis were the most discriminatory species observed. Number of species, species richness and species diversity observed in dead maerl were considerably greater than in all other substrata. There were no apparent r- or K-selected species associations with particular substratum types. Differences observed may have been linked to habitat heterogeneity affecting differential survival (e.g. predator-prey interactions) both during settlement and post-settlement phases.
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37.
  • James, Kelly, et al. (författare)
  • It's time to broaden what we consider a 'blue carbon ecosystem'
  • 2024
  • Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 30:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Photoautotrophic marine ecosystems can lock up organic carbon in their biomass and the associated organic sediments they trap over millennia and are thus regarded as blue carbon ecosystems. Because of the ability of marine ecosystems to lock up organic carbon for millennia, blue carbon is receiving much attention within the United Nations' 2030 Agenda for Sustainable Development as a nature-based solution (NBS) to climate change, but classically still focuses on seagrass meadows, mangrove forests, and tidal marshes. However, other coastal ecosystems could also be important for blue carbon storage, but remain largely neglected in both carbon cycling budgets and NBS strategic planning. Using a meta-analysis of 253 research publications, we identify other coastal ecosystems—including mud flats, fjords, coralline algal (rhodolith) beds, and some components or coral reef systems—with a strong capacity to act as blue carbon sinks in certain situations. Features that promote blue carbon burial within these ‘non-classical’ blue carbon ecosystems included: (1) balancing of carbon release by calcification via carbon uptake at the individual and ecosystem levels; (2) high rates of allochthonous organic carbon supply because of high particle trapping capacity; (3) high rates of carbon preservation and low remineralization rates; and (4) location in depositional environments. Some of these features are context-dependent, meaning that these ecosystems were blue carbon sinks in some locations, but not others. Therefore, we provide a universal framework that can evaluate the likelihood of a given ecosystem to behave as a blue carbon sink for a given context. Overall, this paper seeks to encourage consideration of non-classical blue carbon ecosystems within NBS strategies, allowing more complete blue carbon accounting.
  •  
38.
  • Kamenos, Nicholas A., et al. (författare)
  • Attachment of the juvenile queen scallop (Aequipecten opercularis (L.)) to Maerl in mesocosm conditions; juvenile habitat selection
  • 2004
  • Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier. - 0022-0981 .- 1879-1697. ; 306:2, s. 139-155
  • Tidskriftsartikel (refereegranskat)abstract
    • Substratum un-acclimated juvenile queen scallops (Aequipecten opercularis) (< 18 mm and 1830 mm shell height) were released in equal numbers onto pristine live maerl (PLM), impacted dead maerl (IDM), gravel and sand in choice chambers. Their habitat selection was monitored over a 4-day period in control and predator treatments (utilising Asterias rubens L. and Carcinus maenas (L.)). Microhabitat use of PLM by juvenile queen scallops and the presence of cues in live maerl were also investigated.In control and predator treatments juvenile queen scallops were observed to attach preferentially to PLM than IDM, gravel or sand. Juvenile queen scallops were observed to maintain a more exposed attachment site in the absence of predators but sought refuge within and between maerl nodules in the presence of both predators. Smaller queen scallops (< 18 mm shell height) were more efficient at utilising maerl thalli as a refuge. Juvenile A. opercularis showed hierarchical cue responses mediated by predator presence, i.e. responding favourably to a factor associated with live maerl presence irrespective of heterogeneity in the absence of predators but favourably to higher maerl heterogeneity in their presence. If they also preferentially attach to PLM in the field, at some sites where PLM grounds cover large areas, they may thus be considered to constitute 'nursery areas'. Habitat attachment preference appears to be predetermined and not a result of localised predator avoidance; however, habitat usage changes in the presence of predators. Maerl beds have been shown to be easily damaged by scallop dredging in Scotland and if such nursery areas are being destroyed extensively in the field, this could damage recruitment to localised adult populations. 
  •  
39.
  • Kamenos, Nicholas A., et al. (författare)
  • Commentary : Commentary on Reconstructing Four Centuries of Temperature-Induced Bleaching on the Great Barrier Reef by Hoegh-Guldberg et al. 2019 and DeCarlo 2020
  • 2020
  • Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 7
  • Tidskriftsartikel (refereegranskat)abstract
    • Mass coral bleaching events during the last 20 years have caused major concern over the future of coral reefs worldwide. Despite damage to these key ecological cornerstones, little is known about bleaching frequency prior to 1979 when regular modern systematic scientific observations began on the Great Barrier Reef (GBR). To understand the longer-term relevance of current bleaching trajectories, the likelihood of future coral acclimatization and adaptation, and thus persistence of corals, we reconstructed centennial length GBR bleaching records in Kamenos and Hennige (2018) (hereafter KH18). We thank Hoegh-Guldberg et al. (2019) and DeCarlo (2020) (hereafter HG19 and DeC20, respectively) for considering our paper. HG19 and DeC20 question our approach; however here we demonstrate: 1) our use of ERSST data is during their most accurate and precise time period, 2) that linear extension is recording bleaching and that within and between-coral colony variability exists, necessitating a decadally binned approach, 3) that HG19 make errors in their dataset comparisons (also detected by DeC20), and 4) that HG19 and DeC20 use the observational data record beyond its power as it is not resolved by effort or species. Overall, we demonstrate the value of sclerochronological-type approaches over longer time-scales and the existing evidence of historic coral mortality, in contrary to Commentary assertions.
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40.
  • Kamenos, Nicholas A., et al. (författare)
  • Coralline algae are global palaeothermometers with bi-weekly resolution
  • 2008
  • Ingår i: Geochimica et Cosmochimica Acta. - : Elsevier. - 0016-7037 .- 1872-9533. ; 72:3, s. 771-779
  • Tidskriftsartikel (refereegranskat)abstract
    • High resolution palaeoclimate data are required for the Holocene to resolve differences recorded by current proxies. The pole to pole distribution of rhodoliths (coralline algae) with their annual and sub-annual calcite bands make these attractive candidates for such a role. These bands contain climate information in the form of elemental traces. In situ temperature (IST) was recorded at two rhodolith beds for 1.5 years. The concentrations of MgCO3 and SrCO3 (mol %) deposited in Lithothamion glaciale and Phymatolithon calcareum over this 18- month period were determined using electron and ion microprobes. Highly significant linear relationships exist between Mg, Sr and IST as well as sea surface temperature. Calibration between Mg concentration and IST was used to obtain a 2-year temperature profile from a subfossil rhodolith thallus indicating half the seasonal peak-to-peak temperature amplitude earlier during the Holocene than the present day. Both slow-growing species (<200 mu m year(-1)) allowed sampling resolutions of 23 year-1 which is equivalent to I reading every 2 weeks. Sub-monthly Mg and Sr records in rhodoliths make them unique globally distributed palaeothermometers which may help refine regional climate histories during the Holocene. 
  •  
41.
  • Kamenos, Nicholas A., et al. (författare)
  • Coralline algae in a naturally acidified ecosystem persist by maintaining control of skeletal mineralogy and size
  • 2016
  • Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : Royal Society Publishing. - 0962-8452 .- 1471-2954. ; 283:1840
  • Tidskriftsartikel (refereegranskat)abstract
    • To understand the effects of ocean acidification (OA) on marine calcifiers, the trade-offs among different sublethal responses within individual species and the emergent effects of these trade-offs must be determined in an ecosystem setting. Crustose coralline algae (CCA) provide a model to test the ecological consequences of such sublethal effects as they are important in ecosystem functioning, service provision, carbon cycling and use dissolved inorganic carbon to calcify and photosynthesize. Settlement tiles were placed in ambient pH, low pH and extremely low pH conditions for 14 months at a natural CO2 vent. The size, magnesium (Mg) content and molecular-scale skeletal disorder of CCA patches were assessed at 3.5, 6.5 and 14 months from tile deployment. Despite reductions in their abundance in low pH, the largest CCA from ambient and low pH zones were of similar sizes and had similar Mg content and skeletal disorder. This suggests that the most resilient CCA in low pH did not trade-off skeletal structure to maintain growth. CCA that settled in the extremely low pH, however, were significantly smaller and exhibited altered skeletal mineralogy (high Mg calcite to gypsum (hydrated calcium sulfate)), although at present it is unclear if these mineralogical changes offered any fitness benefits in extreme low pH. This field assessment of biological effects of OA provides endpoint information needed to generate an ecosystem relevant understanding of calcifying system persistence.
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42.
  • Kamenos, Nicholas A., et al. (författare)
  • Coralline algal structure is more sensitive to rate, rather than the magnitude, of ocean acidification
  • 2013
  • Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 19:12, s. 3621-3628
  • Tidskriftsartikel (refereegranskat)abstract
    • Marine pCO2 enrichment via ocean acidification (OA), upwelling and release from carbon capture and storage (CCS) facilities is projected to have devastating impacts on marine biomineralisers and the services they provide. However, empirical studies using stable endpoint pCO2 concentrations find species exhibit variable biological and geochemical responses rather than the expected negative patterns. In addition, the carbonate chemistry of many marine systems is now being observed to be more variable than previously thought. To underpin more robust projections of future OA impacts on marine biomineralisers and their role in ecosystem service provision, we investigate coralline algal responses to realistically variable scenarios of marine pCO2 enrichment. Coralline algae are important in ecosystem function; providing habitats and nursery areas, hosting high biodiversity, stabilizing reef structures and contributing to the carbon cycle. Red coralline marine algae were exposed for 80 days to one of three pH treatments: (i) current pH (control); (ii) low pH (7.7) representing OA change; and (iii) an abrupt drop to low pH (7.7) representing the higher rates of pH change observed at natural vent systems, in areas of upwelling and during CCS releases. We demonstrate that red coralline algae respond differently to the rate and the magnitude of pH change induced by pCO2 enrichment. At low pH, coralline algae survived by increasing their calcification rates. However, when the change to low pH occurred at a fast rate we detected, using Raman spectroscopy, weaknesses in the calcite skeleton, with evidence of dissolution and molecular positional disorder. This suggests that, while coralline algae will continue to calcify, they may be structurally weakened, putting at risk the ecosystem services they provide. Notwithstanding evolutionary adaptation, the ability of coralline algae to cope with OA may thus be determined primarily by the rate, rather than magnitude, at which pCO2 enrichment occurs.
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43.
  • Kamenos, Nicholas A., et al. (författare)
  • Maerl grounds provide both refuge and high growth potential for juvenile queen scallops (Aequipecten opercularis L.)
  • 2004
  • Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier. - 0022-0981 .- 1879-1697. ; 313:2, s. 241-254
  • Tidskriftsartikel (refereegranskat)abstract
    • Human damage to biogenic substrata such as maerl has been receiving increasing attention recently. Maerl forms highly biodiverse and heterogeneous habitats composed of loose-lying coralline red algae, which fulfil nursery area prerequisites for queen scallops (Aequipecten opercularis) and other invertebrates. The benefits obtained by queen scallops utilising maerl were poorly understood, so we used both laboratory predation and field tethering experiments to investigate the refuge and growth potential provided by pristine live maerl (PLM) grounds over other common substrata. In aquaria, more juvenile queen scallops (<35 mm shell height) survived on PLM than on gravel substrata in the presence of the crab Carcinus maenas or the starfish Asterias rubens. Field tethering experiments indicated similar survivorship of juvenile queen scallops on PLM and gravel; additionally, their growth rates were similar on both substrata. PLM allows scallops to seek refuge from predators and position themselves to optimise their food supply. Other bivalve refugia have been shown to provide poor food supply as a consequence of their high heterogeneity, yet maerl grounds provide a 'win-win' scallop nursery area coupling refuge availability with high food supply. 
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44.
  • Kamenos, Nicholas A., et al. (författare)
  • Mg-lattice associations in red coralline algae
  • 2009
  • Ingår i: Geochimica et Cosmochimica Acta. - : Elsevier. - 0016-7037 .- 1872-9533. ; 73:7, s. 1901-1907
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent investigations have shown red coralline algae to record ambient temperature in their calcite skeletons. Temperature recorded by variation in Mg concentrations within algal growth bands has sub-annual resolution and high accuracy. The conversion of Mg concentration to temperature is based on the assumption of Ca replacement by Mg within the algal calcite skeleton at higher temperatures. While Mg-temperature relationships in coralline algae have been calibrated for some species, the location of Mg within the calcite lattice remains unknown. Critically, if Mg is not a lattice component but associated with organic components this could lead to erroneous temperature records. Before coralline algae are used in large scale climate reconstructions it is therefore important to determine the location of Mg. Synchrotron Mg-X-ray absorbance near edge structure (XANES) indicates that Mg is associated with the calcite lattice in Lithothamnion glaciale (contemporary free-living, contemporary encrusting and sub-fossil free-living) and Phymatolithon calcareum (contemporary free-living) coralline algae. Mg is deposited within the calcite lattice in all seasons (L. glaciale & P. calcareum) and thallus areas (P. calcareum). These results suggest L. glaciale and P. calcareum are robust Mg-palaeoternperature proxies. We suggest that similar confirmation be obtained for Mg associations in other species of red coralline algae aiding our understanding of their role in climate reconstruction at large spatial scales.
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45.
  • Kamenos, Nicholas A. (författare)
  • North Atlantic summers have warmed more than winters since 1353, and the response of marine zooplankton
  • 2010
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 107:52, s. 22442-22447
  • Tidskriftsartikel (refereegranskat)abstract
    • Modeling and measurements show that Atlantic marine temperatures are rising; however, the low temporal resolution of models and restricted spatial resolution of measurements (i) mask regional details critical for determining the rate and extent of climate variability, and (ii) prevent robust determination of climatic impacts on marine ecosystems. To address both issues for the North East Atlantic, a fortnightly resolution marine climate record from 1353-2006 was constructed for shallow inshore waters and compared to changes in marine zooplankton abundance. For the first time summer marine temperatures are shown to have increased nearly twice as much as winter temperatures since 1353. Additional climatic instability began in 1700 characterized by similar to 5-65 year climate oscillations that appear to be a recent phenomenon. Enhanced summer-specific warming reduced the abundance of the copepod Calanus finmarchicus, a key food item of cod, and led to significantly lower projected abundances by 2040 than at present. The faster increase of summer marine temperatures has implications for climate projections and affects abundance, and thus biomass, near the base of the marine food web with potentially significant feedback effects for marine food security.
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46.
  • Kamenos, Nicholas A., et al. (författare)
  • Nursery-area function of maerl grounds for juvenile queen scallops Aequipecten opercularis and other invertebrates
  • 2004
  • Ingår i: Marine Ecology Progress Series. - : Inter-Research. - 0171-8630 .- 1616-1599. ; 274, s. 183-189
  • Tidskriftsartikel (refereegranskat)abstract
    • The services provided by coastal ecosystems such as mangrove forests and sea-grass beds are becoming increasingly recognised, yet the functional role of maerl beds has not been addressed. Maerl forms highly biodiverse habitats composed of loose-lying coralline red algae which build up over thousands of years. These carbonate-rich deposits occur in photic areas with strong water movement; they have a widespread global distribution yet remain one of the most overlooked shallow-water marine habitats, with little known about the ecosystem services maerl may provide. Our diving research in Scotland has shown that pristine live maerl (PLM) grounds fulfil nursery area prerequisites for commercial populations of queen scallops Aequipecten opercularis and other invertebrates, such as the soft clam Mya arenaria, the sea urchins Psammechinus miliaris and Echinus esculentus, and the starfish Asterias rubens, more effectively than impacted dead maerl and other common substrata, The complex architecture of maerl beds attracts high densities of these juvenile invertebrates, which use PLM grounds as nursery areas in preference to adjacent substrata. Considering its global distribution, it is highly likely that ecosystem services provided by maerl are considerable. Maerl is easily damaged and killed by a variety of human activities, yet its protection would maintain vital nursery area function, benefiting commercial fishery yields and, pivotally, regional biodiversity.
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47.
  • Kamenos, Nicholas A., et al. (författare)
  • Reconstructing Four Centuries of Temperature-Induced Coral Bleaching on the Great Barrier Reef
  • 2018
  • Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 5
  • Tidskriftsartikel (refereegranskat)abstract
    • Mass coral bleaching events during the last 20 years have caused major concern over the future of coral reefs worldwide. Despite damage to key ecosystem engineers, little is known about bleaching frequency prior to 1979 when regular modern systematic scientific observations began on the Great Barrier Reef (GBR). To understand the longer-term relevance of current bleaching trajectories, the likelihood of future coral acclimatization and adaptation, and thus persistence of corals, records, and drivers of natural pre-industrial bleaching frequency and prevalence are needed. Here, we use linear extensions from 44 overlapping GBR coral cores to extend the observational bleaching record by reconstructing temperature-induced bleaching patterns over 381 years spanning 1620-2001. Porites spp. corals exhibited variable bleaching patterns with bleaching frequency (number of bleaching years per decade) increasing (1620-1753), decreasing (1754-1820), and increasing (1821-2001) again. Bleaching prevalence (the proportion of cores exhibiting bleaching) fell (1670-1774) before increasing by 10% since the late 1790s concurrent with positive temperature anomalies, placing recently observed increases in GBR coral bleaching into a wider context. Spatial inconsistency along with historically diverging patterns of bleaching frequency and prevalence provide queries over the capacity for holobiont (the coral host, the symbiotic microalgae and associated microorganisms) acclimatization and adaptation via bleaching, but reconstructed increases in bleaching frequency and prevalence, may suggest coral populations are reaching an upper bleaching threshold, a "tipping point" beyond which coral survival is uncertain.
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48.
  • Kamenos, Nicholas A., et al. (författare)
  • Reconstructing Greenland ice sheet runoff using coralline algae
  • 2012
  • Ingår i: Geology. - 0091-7613 .- 1943-2682. ; 40:12, s. 1095-1098
  • Tidskriftsartikel (refereegranskat)abstract
    • The Greenland ice sheet (GrIS) contains the largest store of fresh water in the Northern Hemisphere, equivalent to similar to 7.4 m of eustatic sea-level rise, but its impacts on current, past, and future sea level, ocean circulation, and European climate are poorly understood. Previous estimates of GrIS melt, from 26 yr of satellite observations and temperature-driven melt models over 48 yr, show increasing melt trends. There are, however, no runoff data of comparable duration with which to validate the relationship between the spatial extent of melting and runoff or temperature-based runoff models. Further, longer runoff records are needed to extend the melt pattern of Greenland to centennial timescales, enabling recent observations and trends to be put into a better historical context. We have developed a new GrIS runoff proxy by extracting information on relative salinity changes from annual growth bands of red coralline algae. We observed significant negative relationships between historic runoff, relative salinity, and marine summer temperature in Sondre Stromfjord, Greenland. We produce the first reconstruction of runoff from a section of the GrIS that discharges into Sondre Stromfjord over several decades (1939-2002) and record a trend of increasing reconstructed runoff since the mid 1980s. In situ summer marine temperatures followed an equivalent trend. We suggest that since A. D. 1939, atmospheric temperatures have been important in forcing runoff. These results show that our technique has significant potential to enhance understanding of runoff from large ice sheets as it will enable melt reconstruction over centennial to millennial timescales.
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49.
  • Kamenos, Nicholas A., et al. (författare)
  • Red coralline algae as a source of marine biogenic dimethylsulphoniopropionate
  • 2008
  • Ingår i: Marine Ecology Progress Series. - : Inter-Research. - 0171-8630 .- 1616-1599. ; 372, s. 61-66
  • Tidskriftsartikel (refereegranskat)abstract
    • The biogenic gas dimethylsulphide (DMS), derived from dimethylsulphoniopropionate (DMSP), plays an important role in the Earth's albedo, and thus climate regulation, through the formation of aerosols and cloud condensation nuclei. It is estimated that biogenic sources of DMS contribute 42% (mean) of the atmospheric sulphur burden and, significantly, > 90% of that contribution is derived from marine sources. Phytoplankton, macroalgae and corals are thought to be the main producers of marine biogenic DMSP. Red coralline algae (known as maerl or rhodoliths) cover extensive areas of seabed, yet despite their widespread global distribution, maerl-forming coralline algae have received little or no attention regarding their DMSP productivity. In the present study we report for the first time the occurrence of DMSP in 2 species of maerl. DMSP concentrations were found to average 1914 nmol g(-1) for soft tissue and estimated to be 637 mu mol m(-2) for maerl beds. In incubation experiments, maerl led to a dissolved DMSP (DMSPd) increase at a rate of 57.4 to 767.6 nmol m(-2) d(-1) in surrounding seawater, indicating that maerl contributes to DMSPd concentrations in the adjacent water column. Results show that maerl beds are a previously undiscovered source of DMSP in the marine environment. Further study is warranted to assess the significance of maerl as a source of DMSP and the role coralline algae may play in the biogenic sulphur cycle.
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50.
  • Kamenos, Nicholas A., et al. (författare)
  • Small-scale distribution of juvenile gadoids in shallow inshore waters; what role does maerl play?
  • 2004
  • Ingår i: ICES Journal of Marine Science. - : Elsevier. - 1054-3139 .- 1095-9289. ; 61:3, s. 422-429
  • Tidskriftsartikel (refereegranskat)abstract
    • The indirect effects of demersal fisheries, such as habitat degradation, are currently thought to be impacting gadoid stocks. Maerl fulfils nursery area prerequisites for several invertebrate species, so its role in similar ecosystem service provision for gadoids has been addressed. Juvenile cod (Gadus morhua), saithe (Pollachius virens), and pollack (Pollachius pollachius) in shallow (< 7 m) inshore waters were surveyed with fykenets and scuba off western Scotland over a period of 12 months. Juvenile densities were highest from September to November, and at that time, significantly more were present during the day and associated with maerl (that lacked macroalgal cover) than with heavily vegetated rocky and gravel substrata. Juvenile cod were present throughout the year, whereas saithe appeared in July, and pollack from September to January. With its abundance of food, maerl probably has a high holding capacity for juvenile gadoids, and thus is an important part of the inshore nursery system. 
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