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Hodges, Lance T., e Ariel A. Roth. "Orientation of corals and stromatoporoids in some Pleistocene, Devonian, and Silurian reef facies". Journal of Paleontology 60, n.º 6 (novembro de 1986): 1147–58. http://dx.doi.org/10.1017/s0022336000002936.
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A quantitative study was made of the orientation of corals and stromatoporoids in reef core, flank, and interreef rocks representing three geological periods at eight sites, including the Florida Keys (Pleistocene), Ridgemount, Ontario (Devonian), and Pekin, New York, Maumee and Rockford, Ohio, and Bluffton and Delphi, Indiana (Silurian). Orientation, width, and height were measured for each fossil as seen in outcrop.Fossils in Pleistocene and Silurian reef core facies have pronounced upward orientation, suggesting that most fossils are in growth location, or that the reefs were moved to their present location without appreciable tilting. Silurian distal flank facies have approximately random coral orientations, while the proximal (near-core) Silurian flank facies at Rockford has coral orientations with some upward bias. Coral width is greater than or equal to coral height (on outcrop) for 79% of the corals at all flank sites, and for 80% of the corals at the interreef site, an indicator of transport when taken with orientation data. This study permits reef facies differentiation and illustrates that fossil orientation is a useful technique for studying reefs.
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Salles, Tristan, Jodie Pall, Jody M. Webster e Belinda Dechnik. "Exploring coral reef responses to millennial-scale climatic forcings: insights from the 1-D numerical tool pyReef-Core v1.0". Geoscientific Model Development 11, n.º 6 (8 de junho de 2018): 2093–110. http://dx.doi.org/10.5194/gmd-11-2093-2018.
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Abstract. Assemblages of corals characterise specific reef biozones and the environmental conditions that change spatially across a reef and with depth. Drill cores through fossil reefs record the time and depth distribution of assemblages, which captures a partial history of the vertical growth response of reefs to changing palaeoenvironmental conditions. The effects of environmental factors on reef growth are well understood on ecological timescales but are poorly constrained at centennial to geological timescales. pyReef-Core is a stratigraphic forward model designed to solve the problem of unobservable environmental processes controlling vertical reef development by simulating the physical, biological and sedimentological processes that determine vertical assemblage changes in drill cores. It models the stratigraphic development of coral reefs at centennial to millennial timescales under environmental forcing conditions including accommodation (relative sea-level upward growth), oceanic variability (flow speed, nutrients, pH and temperature), sediment input and tectonics. It also simulates competitive coral assemblage interactions using the generalised Lotka–Volterra system of equations (GLVEs) and can be used to infer the influence of environmental conditions on the zonation and vertical accretion and stratigraphic succession of coral assemblages over decadal timescales and greater. The tool can quantitatively test carbonate platform development under the influence of ecological and environmental processes and efficiently interpret vertical growth and karstification patterns observed in drill cores. We provide two realistic case studies illustrating the basic capabilities of the model and use it to reconstruct (1) the Holocene history (from 8500 years to present) of coral community responses to environmental changes and (2) the evolution of an idealised coral reef core since the last interglacial (from 140 000 years to present) under the influence of sea-level change, subsidence and karstification. We find that the model reproduces the details of the formation of existing coral reef stratigraphic sequences both in terms of assemblages succession, accretion rates and depositional thicknesses. It can be applied to estimate the impact of changing environmental conditions on growth rates and patterns under many different settings and initial conditions.
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Gulliver, Pauline, Suzanne Palmer, Chris Perry e Scott Smithers. "Are Coral Clasts from a Turbid Near-Shore Reef Environment a Suitable Material for Radiocarbon Analysis?" Radiocarbon 55, n.º 2 (2013): 624–30. http://dx.doi.org/10.1017/s0033822200057775.
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Use of coral skeletons to determine growth histories of reefs situated in warm, clear tropical waters is well established. Recently, however, there has been increasing awareness of the significance of reefs occurring in environments that are considered as marginal for coral growth, such as turbid inshore settings characterized by episodes of elevated turbidity, low light penetration, and periodic sediment burial. While these conditions are generally considered as limiting for coral growth, coral reefs in these settings can exhibit high live coral cover and species diversity, and thus can be both ecologically and geologically significant. Turbid-zone reefs are also commonly concentrated along eroding shorelines with many analogues to erosional shorelines developed during the Holocene transgression. A growing number of studies of these previously undocumented reefs reveal that the reef deposits are detrital in nature, comprising a framework dominated by reef rubble and coral clasts and set within a fine-grained terrigenous sediment matrix. In addition to the recognized effects of diagenesis or algal encrustations on the radiocarbon signature of coral samples, episodic high-energy events may rework sediments and can result in age reversals in the same stratigraphic unit. As in other reef settings, the possibility of such reworking can complicate the reconstruction of turbid-zone reef growth chronologies. In order to test the accuracy of dating coral clasts for developing growth histories of these reef deposits, 5 replicate samples from 5 separate coral clasts were taken from 2 sedimentary units in a core collected from Paluma Shoals, an inshore turbid-zone reef located in Halifax Bay, central Great Barrier Reef, Australia. Results show that where care is taken to screen the clasts for skeletal preservation, primary mineralogical structures, and δ13C values indicative of marine carbonate, then reliable 14C dates can be recovered from individual turbid reef coral samples. In addition, the results show that these individual clasts were deposited coevally.
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Ferratges, Fernando A., Samuel Zamora e Marcos Aurell. "Systematics and distribution of decapod crustaceans associated with late Eocene coral buildups from the southern Pyrenees (Spain)". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 296, n.º 1 (1 de maio de 2020): 79–100. http://dx.doi.org/10.1127/njgpa/2020/0893.
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A new decapod crustacean assemblage associated with late Eocene coral reef deposits in northeast Spain (southern Pyrenees) is recorded; it includes Gemmellarocarcinus riglosensis sp. nov., Daira corallina sp. nov., Lobogalenopsis joei sp. nov., Liopsalis cf. anodon (Bittner, 1875) and Galenopsis crassifrons A. Milne- Edwards, 1865. The genera Gemmellarocarcinus, Daira and Lobogalenopsis are here recorded for the first time from Eocene strata of the Iberian Peninsula, extending their palaeobiogeographical distribution. Detailed sampling from three different coral reef facies within the La Peña buildup, here referred to as branching, tabular and massive, suggest that the core of the reef, which was dominated by branching corals, hosted the highest diversity and abundance of decapod crustaceans. Daira corallina sp. nov. predominated in the branching corals facies, while G. crassiforns was the most abundant taxon within the tabular coral facies and carpiliids showed preferences for environments with massive corals. Thus, this constitutes a good example of primary ecological zonation among decapod crustaceans within a discrete reef.
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Jackson, Rebecca L., Albert J. Gabric e Roger Cropp. "Coral reefs as a source of climate-active aerosols". PeerJ 8 (29 de setembro de 2020): e10023. http://dx.doi.org/10.7717/peerj.10023.
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We review the evidence for bio-regulation by coral reefs of local climate through stress-induced emissions of aerosol precursors, such as dimethylsulfide. This is an issue that goes to the core of the coral ecosystem’s ability to maintain homeostasis in the face of increasing climate change impacts and other anthropogenic pressures. We examine this through an analysis of data on aerosol emissions by corals of the Great Barrier Reef, Australia. We focus on the relationship with local stressors, such as surface irradiance levels and sea surface temperature, both before and after notable coral bleaching events. We conclude that coral reefs may be able to regulate their exposure to environmental stressors through modification of the optical properties of the atmosphere, however this ability may be impaired as climate change intensifies.
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Hongo, Chuki, Haruko Kurihara e Yimnang Golbuu. "Projecting of wave height and water level on reef-lined coasts due to intensified tropical cyclones and sea level rise in Palau to 2100". Natural Hazards and Earth System Sciences 18, n.º 2 (2 de março de 2018): 669–86. http://dx.doi.org/10.5194/nhess-18-669-2018.
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Abstract. Tropical cyclones (TCs) and sea level rise (SLR) cause major problems including beach erosion, saltwater intrusion into groundwater, and damage to infrastructure in coastal areas. The magnitude and extent of damage is predicted to increase as a consequence of future climate change and local factors. Upward reef growth has attracted attention for its role as a natural breakwater, reducing the risks of natural disasters to coastal communities. However, projections of change in the risk to coastal reefs under conditions of intensified TCs and SLR are poorly quantified. In this study we projected the wave height and water level on Melekeok reef in the Palau Islands by 2100, based on wave simulations under intensified TCs (significant wave height at the outer ocean: SWHo = 8.7–11.0 m; significant wave period at the outer ocean: SWPo = 13–15 s) and SLR (0.24–0.98 m). To understand effects of upward reef growth on the reduction of the wave height and water level, the simulation was conducted for two reef condition scenarios: a degraded reef and a healthy reef. Moreover, analyses of reef growth based on a drilled core provided an assessment of the coral community and rate of reef production necessary to reduce the risk from TCs and SLR on the coastal areas. According to our calculations under intensified TCs and SLR by 2100, significant wave heights at the reef flat (SWHr) will increase from 1.05–1.24 m at present to 2.14 m if reefs are degraded. Similarly, by 2100 the water level at the shoreline (WLs) will increase from 0.86–2.10 m at present to 1.19–3.45 m if reefs are degraded. These predicted changes will probably cause beach erosion, saltwater intrusion into groundwater, and damage to infrastructure, because the coastal village is located at ∼ 3 m above the present mean sea level. These findings imply that even if the SWHr is decreased by only 0.1 m by upward reef growth, it will probably reduce the risks of costal damages. Our results showed that a healthy reef will reduce a maximum of 0.44 m of the SWHr. According to analysis of drilled core, corymbose Acropora corals will be key to reducing the risks, and 2.6–5.8 kg CaCO3 m−2 yr−1, equivalent to > 8 % of coral cover, will be required to keep a healthy reef by 2100. This study highlights that the maintaining reef growth (as a function of coral cover) in the future is effective in reducing the risk of coastal damage arising from wave action. Although the present study focuses on Melekeok fringing reef, many coral reefs are in the same situation under conditions of intensified TCs and SLR, and therefore the results of this study are applicable to other reefs. These researches are critical in guiding policy development directed at disaster prevention for small island nations and for developing and developed countries.
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Birkeland, C., A. Green, A. Lawrence, G. Coward, M. Vaeoso e D. Fenner. "Different resiliencies in coral communities over ecological and geological time scales in American Samoa". Marine Ecology Progress Series 673 (2 de setembro de 2021): 55–68. http://dx.doi.org/10.3354/meps13792.
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In 1917, Alfred Mayor surveyed a 270 m transect on a reef flat on American Samoa. Eleven surveys were conducted on the transect from 1917 to 2019. The coral community on the reef crest was resilient over the century, occasionally being seriously damaged but always recovering rapidly. In contrast, the originally most dense coral community on the reef flat has been steadily deteriorating throughout the century. Resilience of coral communities in regions of high wave energy on the reef crests was associated with the important binding function of the crustose coralline alga (CCA) Porolithon onkodes. Successful coral recruits were found on CCA 94% of the time, yet living coral cover correlated negatively with CCA cover as they became alternative winners in competition. Mayor drilled a core from the transect on the surface to the basalt base of the reef 48 m below. Communities on Aua reef were dominated by scleractinians through the Holocene, while cores on another transect 2 km away showed the reef was occupied by alcyonaceans of the genus Sinularia, which built the massive reef with spiculite to the basalt base 37 m below. Despite periods of sea levels rising 9 to 15 times the rate of reef accretion, the reefs never drowned. The consistency of scleractinians on Aua reef and Sinularia on Utulei Reef 2 km away during the Holocene was because the shape of the bay allowed more water motion on Aua reef. After 10700 yr of reef building by octocorals, coastal construction terminated this spiculite-reef development.
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Afandy, Zulfikar, Ario Damar e Syamsul Bahri Agus. "Coral Recruitment Spatial Distribution in its Relation With Coral Cover and Herbivorous Fish Abundance Within Conservation Area". ILMU KELAUTAN: Indonesian Journal of Marine Sciences 24, n.º 2 (2 de junho de 2019): 91. http://dx.doi.org/10.14710/ik.ijms.24.2.91-98.
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The continuity of coral reef ecosystem highly depends on the new coral larvae recruitment process. Hence, the information regarding distribution, the abundance of corals, and its relation to other variables are highly important in that ecosystem management. Research was conducted at nine stations represented each zone at the conservation area of Kapoposang Marine Tourism Park (TWP Kapoposang). This research aims at seeking for spatial variations of the abundance of coral recruitment at three primary zones monitored (core zone, sustainable fishing zone and utilization zone) and we further identified its relations with spatial variation of herbivorous fishes abundance and coral cover’s condition at those zones. The coral recruitment observation employed transect quadrat sampling method with size of 1x1 meter and 10 times repetition at a similar depth, and the coral recruitment abundance measurement in natural habitat based on the amounts of juvenile corals has been defined as coral colony with size of ≤10 cm. Overall, this research has found 534 coral juveniles consisted of 19 genera and 7 families, and the average of juvenile coral density stood at 5.34±4.45 SE.m-2. The coral reef recruitment category at TWP Kapoposang could be classified as high and its abundance spatial distribution showed no significant differences between each zone, as well as not influenced by either herbivorous fish abundance variable or the percentage of live coral cover.
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Hubbard, Dennis K. "Where's the reef?: a critical reevaluation of the role of framework". Paleontological Society Special Publications 6 (1992): 138. http://dx.doi.org/10.1017/s2475262200006985.
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Despite suggestions to the contrary by Norman Newell, in 1971, the presence of in-place, interlocking framework remains primary among the list of criteria used to recognize “true reefs” in the rock record. This is a logical outgrowth of observations made in modern systems, emphasizing 1) high carbonate-production rates of modern corals, 2) their commonly upright and interlocking architecture, and 3) the abundance and diversity of closely packed organisms on the surface of many modern reefs.Applying a framework-dominated model to ancient reefs, however, has led to repeated frustration and the assumption that the problem is by and large related to the changing nature of reefs through time. Our present attempt to apply uniformitarianism to modern reefs and their ancient counterparts was perhaps best summarized by H. A. Lowenstam, “The present is the key to the Pleistocene… perhaps”.A growing data base from cores through modern reefs implies that much of the problem is related to real differences between what we think constitutes the interior of modern reefs and what is really there. Recognizable coral generally constitutes less than 30% of the reef fabric, based on examination of over 50 cores from a variety of reef types throughout the eastern Caribbean region. Volumetrically, loose sediment and void space comprise a significantly higher portion of the reef interior. Furthermore, obviously in-place and interlocking “framework” is conspicuously absent. Branching Acropora palmata is invariably found in a variety of orientations, implying largely detrital emplacement rather than the preservation of intact and undisturbed colonies. Head corals are generally separated by intervals of detritus or open cavities, rather than sitting atop older colonies. Where rigidity of the reef fabric can be observed, it is almost always a function of secondary encrustation by coralline algae and/or post-depositional marine cementation.The patterns seen in cores are supported by previous budget calculations of carbonate cycling in modern reefs around St. Croix. Bioerosion reduces original carbonate material to sediment, leaving recognizable coral to represent only a small part of the total reef volume. While still a significant component of the total reef fabric, few of the recognizable corals are bound together, and it is difficult to clearly demonstrate that the samples were recovered from life position (although some probably were). At Salt River, recovery was very low, and corals have been demonstrably moved from their original sites of growth.Effective modeling of ancient reefs must take into account the importance of secondary processes that reduce and redistribute the original carbonate material produced by corals. Combined with physical reworking, cementation and encrustation, these destructive processes result in a deposit that resembles more a pile of reef debris than the coherent assemblage of in-place, interlocking framework usually conjured up to represent the modern-reef interior. While still of great importance, constructional processes that are so evident on the reef surface must be viewed within the context of other physical, chemical and biological processes that are reflected in the growing body of core data from modern reefs in the western Atlantic and throughout the world.
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Raphael, Alina, Zvy Dubinsky, David Iluz e Nathan S. Netanyahu. "Neural Network Recognition of Marine Benthos and Corals". Diversity 12, n.º 1 (13 de janeiro de 2020): 29. http://dx.doi.org/10.3390/d12010029.
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We present thorough this review the developments in the field, point out their current limitations, and outline its timelines and unique potential. In order to do so we introduce the methods used in each of the advances in the application of deep learning (DL) to coral research that took place between the years: 2016–2018. DL has unique capability of streamlining the description, analysis, and monitoring of coral reefs, saving time, and obtaining higher reliability and accuracy compared with error-prone human performance. Coral reefs are the most diverse and complex of marine ecosystems, undergoing a severe decline worldwide resulting from the adverse synergistic influences of global climate change, ocean acidification, and seawater warming, exacerbated by anthropogenic eutrophication and pollution. DL is an extension of some of the concepts originating from machine learning that join several multilayered neural networks. Machine learning refers to algorithms that automatically detect patterns in data. In the case of corals these data are underwater photographic images. Based on “learned” patterns, such programs can recognize new images. The novelty of DL is in the use of state-of-art computerized image analyses technologies, and its fully automated methodology of dealing with large data sets of images. Automated Image recognition refers to technologies that identify and detect objects or attributes in a digital video or image automatically. Image recognition classifies data into selected categories out of many. We show that Neural Network methods are already reliable in distinguishing corals from other benthos and non-coral organisms. Automated recognition of live coral cover is a powerful indicator of reef response to slow and transient changes in the environment. Improving automated recognition of coral species, DL methods already recognize decline of coral diversity due to natural and anthropogenic stressors. Diversity indicators can document the effectiveness of reef bioremediation initiatives. We explored the current applications of deep learning for corals and benthic image classification by discussing the most recent studies conducted by researchers. We review the developments in the field, point out their current limitations, and outline their timelines and unique potential. We also discussed a few future research directions in the fields of deep learning. Future needs are the age detection of single species, in order to track trends in their population recruitment, decline, and recovery. Fine resolution, at the polyp level, is still to be developed, in order to allow separation of species with similar macroscopic features. That refinement of DL will allow such comparisons and their analyses. We conclude that the usefulness of future, more refined automatic identification will allow reef comparison, and tracking long term changes in species diversity. The hitherto unused addition of intraspecific coral color parameters, will add the inclusion of physiological coral responses to environmental conditions and change thereof. The core aim of this review was to underscore the strength and reliability of the DL approach for documenting coral reef features based on an evaluation of the currently available published uses of this method. We expect that this review will encourage researchers from computer vision and marine societies to collaborate on similar long-term joint ventures.
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Wooldridge, S. "A new conceptual model of coral biomineralisation: hypoxia as the physiological driver of skeletal extension". Biogeosciences 10, n.º 5 (2 de maio de 2013): 2867–84. http://dx.doi.org/10.5194/bg-10-2867-2013.
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Abstract. That corals skeletons are built of aragonite crystals with taxonomy-linked ultrastructure has been well understood since the 19th century. Yet, the way by which corals control this crystallization process remains an unsolved question. Here, I outline a new conceptual model of coral biomineralisation that endeavours to relate known skeletal features with homeostatic functions beyond traditional growth (structural) determinants. In particular, I propose that the dominant physiological driver of skeletal extension is night-time hypoxia, which is exacerbated by the respiratory oxygen demands of the coral's algal symbionts (= zooxanthellae). The model thus provides a new narrative to explain the high growth rate of symbiotic corals, by equating skeletal deposition with the "work-rate" of the coral host needed to maintain a stable and beneficial symbiosis. In this way, coral skeletons are interpreted as a continuous (long-run) recording unit of the stability and functioning of the coral–algae endosymbiosis. After providing supportive evidence for the model across multiple scales of observation, I use coral core data from the Great Barrier Reef (Australia) to highlight the disturbed nature of the symbiosis in recent decades, but suggest that its onset is consistent with a trajectory that has been followed since at least the start of the 1900s. In concluding, I outline how the proposed capacity of cnidarians (which includes modern reef corals) to overcome the metabolic limitation of hypoxia via skeletogenesis also provides a new hypothesis to explain the sudden appearance in the fossil record of calcified skeletons at the Precambrian–Cambrian transition – and the ensuing rapid appearance of most major animal phyla.
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Wooldridge, S. A. "A new conceptual model of coral biomineralisation: hypoxia as the physiological driver of skeletal extension". Biogeosciences Discussions 9, n.º 9 (18 de setembro de 2012): 12627–66. http://dx.doi.org/10.5194/bgd-9-12627-2012.
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Abstract. That corals skeletons are built of aragonite crystals with taxonomy-linked ultrastructure has been well understood since the 19th century. Yet, the way by which corals control this crystallization process remains an unsolved question. Here, I outline a new conceptual model of coral biominerationsation that endeavours to relate known skeletal features with homeostatic functions beyond traditional growth (structural) determinants. In particular, I propose that the dominant physiological driver of skeletal extension is night-time hypoxia, which is exacerbated by the respiratory oxygen demands of the coral's algal symbionts (= zooxanthellae). The model thus provides a new narrative to explain the high growth rate of symbiotic corals, by equating skeletal deposition with the "work-rate" of the coral host needed to maintain a stable and beneficial symbiosis. In this way, coral skeletons are interpreted as a continuous (long-run) recording unit of the stability and functioning of the coral-algae endosymbiosis. After providing supportive evidence for the model across multiple scales of observation, I use coral core data from the Great Barrier Reef (Australia) to highlight the disturbed nature of the symbiosis in recent decades, but suggest that its onset is consistent with a trajectory that has been followed since at least the start of the 1900's. In concluding, I explain how the evolved capacity of the cnidarians (which now includes modern reef corals) to overcome the metabolic limitation of hypoxia via skeletogenesis, may underpin the sudden appearance in the fossil record of calcified skeletons at the Precambrian-Cambrian transition – and the ensuing rapid appearance of most major animal phyla.
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Wehrmann, L. M., N. J. Knab, H. Pirlet, V. Unnithan, C. Wild e T. G. Ferdelman. "Carbon mineralization and carbonate preservation in modern cold-water coral reef sediments on the Norwegian shelf". Biogeosciences 6, n.º 4 (27 de abril de 2009): 663–80. http://dx.doi.org/10.5194/bg-6-663-2009.
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Abstract. Cold-water coral ecosystems are considered hot-spots of biodiversity and biomass production and may be a regionally important contributor to carbonate production. The impact of these ecosystems on biogeochemical processes and carbonate preservation in associated sediments were studied at Røst Reef and Traenadjupet Reef, two modern (post-glacial) cold-water coral reefs on the Mid-Norwegian shelf. Sulfate and iron reduction as well as carbonate dissolution and precipitation were investigated by combining pore-water geochemical profiles, steady state modeling, as well as solid phase analyses and sulfate reduction rate measurements on gravity cores of up to 3.25 m length. Low extents of sulfate depletion and dissolved inorganic carbon (DIC) production, combined with sulfate reduction rates not exceeding 3 nmol S cm−3 d−1, suggested that overall anaerobic carbon mineralization in the sediments was low. These data showed that the coral fragment-bearing siliciclastic sediments were effectively decoupled from the productive pelagic ecosystem by the complex reef surface framework. Organic matter being mineralized by sulfate reduction was calculated to consist of 57% carbon bound in CH2O groups and 43% carbon in -CH2- groups. Methane concentrations were below 1 μM, and failed to support the hypothesis of a linkage between the distribution of cold-water coral reefs and the presence of hydrocarbon seepage. Reductive iron oxide dissolution linked to microbial sulfate reduction buffered the pore-water carbonate system and inhibited acid-driven coral skeleton dissolution. A large pool of reactive iron was available leading to the formation of iron sulfide minerals. Constant pore-water Ca2+, Mg2+ and Sr2+ concentrations in most cores and decreasing Ca2+ and Sr2+ concentrations with depth in core 23–18 GC indicated diagenetic carbonate precipitation. This was consistent with the excellent preservation of buried coral fragments.
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Wehrmann, L. M., N. J. Knab, H. Pirlet, V. Unnithan, C. Wild e T. G. Ferdelman. "Carbon mineralization and carbonate preservation in modern cold-water coral reef sediments on the Norwegian shelf". Biogeosciences Discussions 5, n.º 6 (17 de dezembro de 2008): 4945–92. http://dx.doi.org/10.5194/bgd-5-4945-2008.
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Abstract. Cold-water coral ecosystems are considered hot-spots of biodiversity and biomass production and may be a regionally important contributor to carbonate production. The impact of these ecosystems on biogeochemical processes and carbonate preservation in associated sediments were studied at Røst Reef and Traenadjupet Reef, two modern (post-glacial) cold-water coral reefs on the Mid-Norwegian shelf. Sulfate and iron reduction as well as carbonate dissolution and precipitation were investigated by combining pore-water geochemical profiles, steady state modeling, as well as solid phase analyses and sulfate reduction rate measurements on gravity cores of up to 3.2 m length. Low extents of sulfate depletion and dissolved inorganic carbon (DIC) production, combined with sulfate reduction rates not exceeding 3 nmolS cm−3 d−1, suggested that overall anaerobic carbon mineralization in the sediments was low. These data showed that the coral fragment-bearing siliciclastic sediments were effectively decoupled from the productive pelagic ecosystem by the complex reef surface framework. Organic matter being mineralized by sulfate reduction was calculated to consist of 57% carbon bound in –CH2O– groups and 43% carbon in –CH2– groups. Methane concentrations were below 1 μM, and failed to support the hypothesis of a linkage between the distribution of cold-water coral reefs and the presence of hydrocarbon seepage. Iron reduction linked to microbial sulfate reduction buffered the pore-water carbonate system and inhibited acid driven coral skeleton dissolution. A large pool of reactive iron was available leading to the formation of iron sulfide minerals. Constant pore-water Ca2+, Mg2+ and Sr2+ concentrations in most cores and decreasing Ca2+ and Sr2+ concentrations with depth in core 23-18 GC indicated diagenetic carbonate precipitation. This was consistent with the excellent preservation of buried coral fragments.
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Gao, Yu-Miao, Ke-Shu Zou, Lei Zhou, Xian-De Huang, Yi-Yang Li, Xiang-Yang Gao, Xiao Chen e Xiao-Yong Zhang. "Deep Insights into Gut Microbiota in Four Carnivorous Coral Reef Fishes from the South China Sea". Microorganisms 8, n.º 3 (18 de março de 2020): 426. http://dx.doi.org/10.3390/microorganisms8030426.
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Investigations of gut microbial diversity among fish to provide baseline data for wild marine fish, especially the carnivorous coral reef fishes of the South China Sea, are lacking. The present study investigated the gut microbiota of four carnivorous coral reef fishes, including Oxycheilinus unifasciatus, Cephalopholis urodeta, Lutjanus kasmira, and Gnathodentex aurolineatus, from the South China Sea for the first time using high-throughput Illumina sequencing. Proteobacteria, Firmicutes, and Bacteroidetes constituted 98% of the gut microbiota of the four fishes, and 20 of the gut microbial genera recovered in this study represent new reports from marine fishes. Comparative analysis indicated that the four fishes shared a similar microbial community, suggesting that diet type (carnivorous) might play a more important role in shaping the gut microbiota of coral reef fishes than the species of fish. Furthermore, the genera Psychrobacter, Escherichia-Shigella, and Vibrio constituted the core microbial community of the four fishes, accounting for 61–91% of the total sequences in each fish. The lack of the genus Epulopiscium in the four fishes was in sharp contrast to what has been found in coral reef fishes from the Red Sea, in which Epulopiscium was shown to be the most dominant gut microbial genus in seven herbivorous coral reef fishes. In addition, while unique gut microbial genera accounted for a small proportion (8–13%) of the total sequences, many such genera were distributed in each coral reef fish species, including several genera (Endozoicomonas, Clostridium, and Staphylococcus) that are frequently found in marine fishes and 11 new reports of gut microbes in marine fishes. The present study expands our knowledge of the diversity and specificity of gut microbes associated with coral reef fishes.
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Hilyana, Sitti, Sadikin Amir e Saptono Waspodo. "Kesesuaian Zonasi Pulau-Pulau Kecil : Studi Kasus Kawasan Konservasi Gili Sulat Gili Lawang Lombok Indonesia". JURNAL SAINS TEKNOLOGI & LINGKUNGAN 6, n.º 2 (31 de dezembro de 2020): 202. http://dx.doi.org/10.29303/jstl.v6i2.183.
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Gili Sulat Gili Lawang are small islands that have high marine biodiversity and have been designated as a Marine Tourism Park (TWP) covering an area of 10,000 hectares. This study aims to analyze the suitability of zoning and analysis of space use in each zone. The data was collected by using a structured interview technique using a questionnaire and Focus Group Discussion (FGD) approach. Zoning suitability analysis used a Geographic Information System (GIS). The assessment showed that the conditions of the mangrove ecosystem, coral reef ecosystem and seagrass ecosystem were in the bad to good categories. Based on the zoning suitability analysis of 193.83 hectares (44.02%) of the coral reef area suitable for the core zone, 143.33 hectares (32.55%) consists of 108 hectares of coral reef ecosystems and 35.43 hectares of seagrass ecosystems suitable for the zone. limited use, and 9,666.47 hectares are suitable for other zones consisting of a coral reef rehabilitation zone covering an area of 93.11 hectares, a protection zone of 93.11 hectares and other waters 8,585.76 hectares.
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Krediet, Cory J., Kim B. Ritchie, Valerie J. Paul e Max Teplitski. "Coral-associated micro-organisms and their roles in promoting coral health and thwarting diseases". Proceedings of the Royal Society B: Biological Sciences 280, n.º 1755 (22 de março de 2013): 20122328. http://dx.doi.org/10.1098/rspb.2012.2328.
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Over the last decade, significant advances have been made in characterization of the coral microbiota. Shifts in its composition often correlate with the appearance of signs of diseases and/or bleaching, thus suggesting a link between microbes, coral health and stability of reef ecosystems. The understanding of interactions in coral-associated microbiota is informed by the on-going characterization of other microbiomes, which suggest that metabolic pathways and functional capabilities define the ‘core’ microbiota more accurately than the taxonomic diversity of its members. Consistent with this hypothesis, there does not appear to be a consensus on the specificity in the interactions of corals with microbial commensals, even though recent studies report potentially beneficial functions of the coral-associated bacteria. They cycle sulphur, fix nitrogen, produce antimicrobial compounds, inhibit cell-to-cell signalling and disrupt virulence in opportunistic pathogens. While their beneficial functions have been documented, it is not certain whether or how these microbes are selected by the hosts. Therefore, understanding the role of innate immunity, signal and nutrient exchange in the establishment of coral microbiota and in controlling its functions will probably reveal ancient, evolutionarily conserved mechanisms that dictate the outcomes of host–microbial interactions, and impact the resilience of the host.
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Fan, Tianlai, Kefu Yu, Jianxin Zhao, Wei Jiang, Shendong Xu, Yu Zhang, Rui Wang et al. "Strontium isotope stratigraphy and paleomagnetic age constraints on the evolution history of coral reef islands, northern South China Sea". GSA Bulletin 132, n.º 3-4 (14 de agosto de 2019): 803–16. http://dx.doi.org/10.1130/b35088.1.
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Abstract Understanding the history of the response of coral reefs to past climate changes can provide valuable information for predicting the future response of modern reefs. However, dating such ancient biotic carbonate is still challenging because of its sensitivity to diagenetic alteration processes, scarcity of well-preserved fossils, and low magnetic mineral content. There have been a long debates about the origin and evolutionary history of coral reefs in the northern South China Sea, mainly due to the lack of direct and reliable age constraints. This provides us with a good opportunity to verify the practicability of different dating approaches, especially the strontium (Sr) isotope analysis of bulk carbonate. Here, we retrieved a 972.55-m-long core from the Xisha Islands to provide a credible chronologic constraint on the carbonate platform evolution. The lithostratigraphy, strontium isotope stratigraphy, and magnetostratigraphy were analyzed throughout the whole reef sequence. The lithostratigraphic results show that the 873.55 m reef sequence developed on an ancient volcaniclastic basement and experienced multiple evolutionary phases. The 87Sr/86Sr results of all 100 bulk carbonate samples vary from 0.708506 to 0.709168 and show a monotonic increase with decreasing depth, except for a few outliers. Trace-element criteria and stable isotope (δ18O and δ13C) methods were applied to these bulk carbonate samples, and results imply that the primary or near-primary seawater 87Sr/86Sr values were likely preserved, although different degrees of diagenetic alteration occurred. In addition, the paleomagnetic results indicate 10 normal polarity and eight reversed polarity magnetozones. Based on the 87Sr/86Sr ratios of the selected 58 samples and paleomagnetic reconstruction of polarity reversals, the bottom of the reef sequence is dated to 19.6 Ma, and the observed polarity chronozones extend from chron C6 (19.722–18.748 Ma) at 866.60 m to present at the top. Based on the new data, we propose a new chronologic framework for the evolutionary history of the reef islands, where: (1) the reefs initiated in the early Miocene (19.6 Ma) and were drowned until 16.26 Ma; (2) during 16.26–10.66 Ma, lagoon to lagoon slope environments prevailed; (3) the lagoon environment progressively transformed into a reef crest environment from 10.66 to 4.36 Ma and 4.36 to 1.59 Ma; and (4) the reef started to be drowned again during 1.59–0 Ma. Our study provides a new and reliable chronologic constraint on the general evolutionary history of the reef islands in the northern South China Sea. Furthermore, the 87Sr/86Sr results from bulk carbonate indicate that strontium isotope stratigraphy is a powerful dating tool only when rigid sample selection, sequential leaching procedures, and strict trace-element and isotopic criteria are applied.
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Brandl, Simon J., Douglas B. Rasher, Isabelle M. Côté, Jordan M. Casey, Emily S. Darling, Jonathan S. Lefcheck e J. Emmett Duffy. "Coral reef ecosystem functioning: eight core processes and the role of biodiversity". Frontiers in Ecology and the Environment 17, n.º 8 (30 de julho de 2019): 445–54. http://dx.doi.org/10.1002/fee.2088.
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Muhammad, M., R. Firdaus, V. Kurnianda, Z. Jalil, C. M. N. ‘Akla e I. J. P. Dewi. "Coral reef and reef fishes of core zone in the marine proctected areas of Aceh Besar, Indonesia". IOP Conference Series: Earth and Environmental Science 674, n.º 1 (1 de fevereiro de 2021): 012078. http://dx.doi.org/10.1088/1755-1315/674/1/012078.
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Gutner-Hoch, Eldad, Hiba Waldman Ben-Asher, Ruth Yam, Aldo Shemesh e Oren Levy. "Identifying genes and regulatory pathways associated with the scleractinian coral calcification process". PeerJ 5 (20 de julho de 2017): e3590. http://dx.doi.org/10.7717/peerj.3590.
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Reef building corals precipitate calcium carbonate as an exo-skeleton and provide substratum for prosperous marine life. Biomineralization of the coral’s skeleton is a developmental process that occurs concurrently with other proliferation processes that control the animal extension and growth. The development of the animal body is regulated by large gene regulatory networks, which control the expression of gene sets that progressively generate developmental patterns in the animal body. In this study we have explored the gene expression profile and signaling pathways followed by the calcification process of a basal metazoan, the Red Sea scleractinian (stony) coral,Stylophora pistillata. When treated by seawater with high calcium concentrations (addition of 100 gm/L, added as CaCl2.2H2O), the coral increases its calcification rates and associated genes were up-regulated as a result, which were then identified. Gene expression was compared between corals treated with elevated and normal calcium concentrations. Calcification rate measurements and gene expression analysis by microarray RNA transcriptional profiling at two time-points (midday and night-time) revealed several genes common within mammalian gene regulatory networks. This study indicates that core genes of the Wnt and TGF-β/BMP signaling pathways may also play roles in development, growth, and biomineralization in early-diverging organisms such as corals.
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Adiyoga, Diaz, Retno Hartati e Wilis Ari Setyati. "Fluktuasi Ikan Karang di Kawasan Konservasi Laut Daerah Gili Sulat dan Gili Lawang, Lombok Timur". Journal of Marine Research 9, n.º 2 (25 de abril de 2020): 175–80. http://dx.doi.org/10.14710/jmr.v9i2.26894.
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ABSTRAK: Keanekaragaman ekosistem pesisir dan laut yang terdapat di Gili Sulat Gili Lawang merupakan salah satu sumberdaya yang penting untuk dilindungi mengingat besarnya ketergantungan masyarakat terhadap ekosistem tersebut. Ekosistem terumbu karang adalah salah satu ekosistem penting di Gili Sulat dan Gili Lawang yang menjadikan ikan dan biota lainnya sebagai tempat tinggal maupun mencari makan. kondisi terumbu karang sangat mempengaruhi kekayaan dan kelimpahan ikan karang. Jika kondisi terumbu karang baik maka kelimpahan ikannya tinggi, begitu pula sebaliknya. Penelitian kelimpahan ikan karang dilakukan pada 14-21 November 2018 di Kawasan Konservasi Laut Daerah Gili Sulat dan Gili Lawang. Pengambilan data menggunakan metode sensus visual untuk ikan karang di kedalaman 8-10 meter dengan 3 buah transek sepanjang 50 meter sejajar dengan garis pantai. Berdasarkan hasil penelitian yang dilakukan di Kawasan Konservasi Laut Daerah Gili Sulat dan Gili Lawang kelimpahan ikan karang, rata – rata nilai kelimpahan ikan karang di zona pemanfaatan paling tinggi yaitu 621 ind/ha, paling rendah pada zona inti sebesar 615 ind/ha dan zona perikanan berkelanjutan sebesar 616 ind/ha ABSTRACT: The diversity of coastal and marine ecosystems found on Gili Sulat Gili Lawang is one of the important resources to protect given the large dependence of the community on these ecosystems. The coral reef ecosystem is one of the important ecosystems on Gili Sulat and Gili Lawang which makes fish and other biota as a place to live or find food. the condition of coral reefs greatly affects the wealth and abundance of reef fish. This research was conducted in November 14-21, 2018. Collecting data of reef fishes abundance using visual census method in 8-10 meter depth, use 3 pieces line transect with 50 meters long an roll out the transect along the shoreline. Based on the results of research conducted in Gili Sulat and Gili Lawang the Marine Protected Area reef fish abundance, the average abundance of reef fish in the utilization zone is highest at 621 ind / ha, the lowest in the core zone is 615 ind / ha and the fishing zone sustainable of 616 ind / ha
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Archer, Stephen D. J., Kevin C. Lee, Tancredi Caruso, Katie King-Miaow, Mike Harvey, Danwei Huang, Benjamin J. Wainwright e Stephen B. Pointing. "Air mass source determines airborne microbial diversity at the ocean–atmosphere interface of the Great Barrier Reef marine ecosystem". ISME Journal 14, n.º 3 (21 de novembro de 2019): 871–76. http://dx.doi.org/10.1038/s41396-019-0555-0.
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AbstractThe atmosphere is the least understood biome on Earth despite its critical role as a microbial transport medium. The influence of surface cover on composition of airborne microbial communities above marine systems is unclear. Here we report evidence for a dynamic microbial presence at the ocean–atmosphere interface of a major marine ecosystem, the Great Barrier Reef, and identify that recent air mass trajectory over an oceanic or continental surface associated with observed shifts in airborne bacterial and fungal diversity. Relative abundance of shared taxa between air and coral microbiomes varied between 2.2 and 8.8% and included those identified as part of the core coral microbiome. We propose that this variable source of atmospheric inputs may in part contribute to the diverse and transient nature of the coral microbiome.
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Brüwer, Jan D., e Christian R. Voolstra. "First insight into the viral community of the cnidarian model metaorganism Aiptasia using RNA-Seq data". PeerJ 6 (1 de março de 2018): e4449. http://dx.doi.org/10.7717/peerj.4449.
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Current research posits that all multicellular organisms live in symbioses with associated microorganisms and form so-called metaorganisms or holobionts. Cnidarian metaorganisms are of specific interest given that stony corals provide the foundation of the globally threatened coral reef ecosystems. To gain first insight into viruses associated with the coral model system Aiptasia (sensu Exaiptasia pallida), we analyzed an existing RNA-Seq dataset of aposymbiotic, partially populated, and fully symbiotic Aiptasia CC7 anemones with Symbiodinium. Our approach included the selective removal of anemone host and algal endosymbiont sequences and subsequent microbial sequence annotation. Of a total of 297 million raw sequence reads, 8.6 million (∼3%) remained after host and endosymbiont sequence removal. Of these, 3,293 sequences could be assigned as of viral origin. Taxonomic annotation of these sequences suggests that Aiptasia is associated with a diverse viral community, comprising 116 viral taxa covering 40 families. The viral assemblage was dominated by viruses from the families Herpesviridae (12.00%), Partitiviridae (9.93%), and Picornaviridae (9.87%). Despite an overall stable viral assemblage, we found that some viral taxa exhibited significant changes in their relative abundance when Aiptasia engaged in a symbiotic relationship with Symbiodinium. Elucidation of viral taxa consistently present across all conditions revealed a core virome of 15 viral taxa from 11 viral families, encompassing many viruses previously reported as members of coral viromes. Despite the non-random selection of viral genetic material due to the nature of the sequencing data analyzed, our study provides a first insight into the viral community associated with Aiptasia. Similarities of the Aiptasia viral community with those of corals corroborate the application of Aiptasia as a model system to study coral holobionts. Further, the change in abundance of certain viral taxa across different symbiotic states suggests a role of viruses in the algal endosymbiosis, but the functional significance of this remains to be determined.
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Daly, R., CAK Daly, AE Gray, LR Peel, L. Gordon, JSE Lea, CR Clarke e KC Weng. "Investigating the efficacy of a proposed marine protected area for the Endangered humphead wrasse Cheilinus undulatus at a remote island group in Seychelles". Endangered Species Research 42 (14 de maio de 2020): 7–20. http://dx.doi.org/10.3354/esr01035.
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The humphead wrasse Cheilinus undulatus is an iconic, ecologically important and Endangered fish species associated with coral reefs in the Indo-Pacific region. Due to its large size and complex life history characteristics, it is vulnerable to overfishing and has undergone substantial population declines in parts of its range. Knowledge of the species’ movement ecology is currently limited to only 2 previous studies, and very little is known about populations in the western Indian Ocean. The present study aimed to use passive acoustic telemetry to investigate the importance of a remote coral reef to a population of humphead wrasse in the Republic of Seychelles, and subsequently assess the efficacy of a proposed marine protected area at this location for protection of the species. Tagged fish (n = 20) exhibited persistent (>500 d) site fidelity, with low dispersal distances (mean ± SD: 6.44 ± 4.0 km) and restricted core activity spaces (50% Brownian bridge kernel utilization density: 0.91 ± 0.61 km2). Additionally, the study site was home to a group of large (total length 97.9 ± 20.6 cm) and currently unexploited humphead wrasse that showed long-term predictable site fidelity and thus could be vulnerable to over-exploitation. The establishment of a proposed no-take marine protected area at the study site would encompass the core home range area of all tagged humphead wrasse and could effectively conserve this stronghold of Endangered fish to ensure the persistence of the species in Seychelles waters.
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Richards, Zoe T., e Jon C. Day. "Biodiversity of the Great Barrier Reef—how adequately is it protected?" PeerJ 6 (8 de maio de 2018): e4747. http://dx.doi.org/10.7717/peerj.4747.
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BackgroundThe Great Barrier Reef (GBR) is the world’s most iconic coral reef ecosystem, recognised internationally as a World Heritage Area of outstanding significance. Safeguarding the biodiversity of this universally important reef is a core legislative objective; however, ongoing cumulative impacts including widespread coral bleaching and other detrimental impacts have heightened conservation concerns for the future of the GBR.MethodsHere we review the literature to report on processes threatening species on the GBR, the status of marine biodiversity, and evaluate the extent of species-level monitoring and reporting. We assess how many species are listed as threatened at a global scale and explore whether these same species are protected under national threatened species legislation. We conclude this review by providing future directions for protecting potentially endangered elements of biodiversity within the GBR.ResultsMost of the threats identified to be harming the diversity of marine life on the GBR over the last two–three decades remain to be effectively addressed and many are worsening. The inherent resilience of this globally significant coral reef ecosystem has been seriously compromised and various elements of the biological diversity for which it is renowned may be at risk of silent extinction. We show at least 136 of the 12,000+ animal species known to occur on the GBR (approximately 20% of the 700 species assessed by the IUCN) occur in elevated categories of threat (Critically Endangered, EndangeredorVulnerable) at a global scale. Despite the wider background level of threat for these 136 species, only 23 of them are listed as threatened under regional or national legislation.DiscussionTo adequately protect the biodiversity values of the GBR, it may be necessary to conduct further targeted species-level monitoring and reporting to complement ecosystem management approaches. Conducting a vigorous value of information analysis would provide the opportunity to evaluate what new and targeted information is necessary to support dynamic management and to safeguard both species and the ecosystem as a whole. Such an analysis would help decision-makers determine if further comprehensive biodiversity surveys are needed, especially for those species recognised to be facing elevated background levels of threat. If further monitoring is undertaken, it will be important to ensure it aligns with and informs the GBRMPA Outlook five-year reporting schedule. The potential also exists to incorporate new environmental DNA technologies into routine monitoring to deliver high-resolution species data and identify indicator species that are cursors of specific disturbances. Unless more targeted action is taken to safeguard biodiversity, we may fail to pass onto future generations many of the values that comprise what is universally regarded as the world’s most iconic coral reef ecosystem.
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Andrews, Allen H., Daria Siciliano, Donald C. Potts, Edward E. DeMartini e Stephannie Covarrubias. "Bomb Radiocarbon and the Hawaiian Archipelago: Coral, Otoliths, and Seawater". Radiocarbon 58, n.º 3 (17 de maio de 2016): 531–48. http://dx.doi.org/10.1017/rdc.2016.32.
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AbstractCorals of the Hawaiian Archipelago are well situated in the North Pacific Gyre (NPG) to record how bomb-produced radiocarbon has been sequestered and transported by the sea. While this signal can be traced accurately through time in reef-building corals and used to infer oceanographic processes and determine the ages of marine organisms, a comprehensive and validated record has been lacking for the Hawaiian Archipelago. In this study, a coral core from Kure Atoll in the northwestern Hawaiian Islands was used to create a high-resolution bomb 14C record for the years 1939–2002, and was then used with other 14C measurements in fish otoliths and seawater to explore differences and similarities in the bomb 14C signal throughout the Hawaiian Archipelago. The Kure Atoll sample series produced a well-defined bomb 14C curve that, with some exceptions, was similar to other coral 14C records from the Hawaiian Archipelago. Subtle differences in the coral 14C records across the region may be explained by the large-scale ocean circulation patterns and decadal cycles of the NPG. The most rapid increase of 14C, in the 1950s and 1960s, showed similar timing across the Hawaiian Archipelago and provides a robust basis for use of bomb 14C dating to obtain high-precision age determinations of marine organisms. Reference otoliths of juvenile fish demonstrated the use of the post-peak 14C decline period as a viable reference in the age validation of younger and more recently collected fishes, and effectively extended the utility of bomb 14C dating to the latest 30 yr.
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Shoguchi, Eiichi, Yuki Yoshioka, Chuya Shinzato, Asuka Arimoto, Debashish Bhattacharya e Noriyuki Satoh. "Correlation between Organelle Genetic Variation and RNA Editing in Dinoflagellates Associated with the Coral Acropora digitifera". Genome Biology and Evolution 12, n.º 3 (27 de fevereiro de 2020): 203–9. http://dx.doi.org/10.1093/gbe/evaa042.
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Abstract In order to develop successful strategies for coral reef preservation, it is critical that the biology of both host corals and symbiotic algae are investigated. In the Ryukyu Archipelago, which encompasses many islands spread over ∼500 km of the Pacific Ocean, four major populations of the coral Acropora digitifera have been studied using whole-genome shotgun (WGS) sequence analysis (Shinzato C, Mungpakdee S, Arakaki N, Satoh N. 2015. Genome-wide single-nucleotide polymorphism (SNP) analysis explains coral diversity and recovery in the Ryukyu Archipelago. Sci Rep. 5:18211.). In contrast, the diversity of the symbiotic dinoflagellates associated with these A. digitifera populations is unknown. It is therefore unclear if these two core components of the coral holobiont share a common evolutionary history. This issue can be addressed for the symbiotic algal populations by studying the organelle genomes of their mitochondria and plastids. Here, we analyzed WGS data from ∼150 adult A. digitifera, and by mapping reads to the available reference genome sequences, we extracted 2,250 sequences representing 15 organelle genes of Symbiodiniaceae. Molecular phylogenetic analyses of these mitochondrial and plastid gene sets revealed that A. digitifera from the southern Yaeyama islands harbor a different Symbiodiniaceae population than the islands of Okinawa and Kerama in the north, indicating that the distribution of symbiont populations partially matches that of the four host populations. Interestingly, we found that numerous SNPs correspond to known RNA-edited sites in 14 of the Symbiodiniaceae organelle genes, with mitochondrial genes showing a stronger correspondence than plastid genes. These results suggest a possible correlation between RNA editing and SNPs in the two organelle genomes of symbiotic dinoflagellates.
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Ling, Juan, Weiguo Zhou, Qingsong Yang, Jianping Yin, Jian Zhang, Qiuying Peng, Xiaofang Huang, Yuhang Zhang e Junde Dong. "Spatial and Species Variations of Bacterial Community Structure and Putative Function in Seagrass Rhizosphere Sediment". Life 11, n.º 8 (20 de agosto de 2021): 852. http://dx.doi.org/10.3390/life11080852.
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Seagrasses are an important part of the coral reef ecosystem, and their rhizosphere microbes are of great ecological importance. However, variations in diversity, composition, and potential functions of bacterial communities in the seagrass rhizosphere of coral reef ecosystems remain unclear. This study employed the high-throughput sequencing based on 16S rDNA gene sequences and functional annotation of prokaryotic taxa (FAPROTAX) analysis to investigate these variations based on seagrass species and sampling locations, respectively. Results demonstrated that the seagrass rhizosphere microbial community was mainly dominated by phylum Proteobacteria (33.47%), Bacteroidetes (23.33%), and Planctomycetes (12.47%), while functional groups were mainly composed of sulfate respiration (14.09%), respiration of sulfur compounds (14.24%), aerobic chemoheterotrophy (20.87%), and chemoheterotrophy (26.85%). Significant differences were evident in alpha diversity, taxonomical composition and putative functional groups based on seagrass species and sampling locations. Moreover, the core microbial community of all investigated samples was identified, accounting for 63.22% of all obtained sequences. Network analysis indicated that most microbes had a positive correlation (82.41%), and two module hubs (phylum Proteobacteria) were investigated. Furthermore, a significant positive correlation was found between the OTUs numbers obtained and the functional groups assigned for seagrass rhizosphere microbial communities (p < 0.01). Our result would facilitate future investigation of the function of seagrass rhizosphere microbes.
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Pinceratto, E. J., e G. Oliver. "COOPERATIVE INDUSTRY APPROACH TO ENVIRONMENTAL INVESTIGATIONS IN THE TIMOR SEA". APPEA Journal 36, n.º 1 (1996): 650. http://dx.doi.org/10.1071/aj95045.
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For more than 20 years, oil and gas exploration and production activities have been conducted in the Timor Sea region, including the Sahul Shelf. The Shelf is a large, shallow platform off the Northern Australian Coast, considered to be a recently drowned part of the Australian Platform. Seismic surveys have indicated submerged banks on the edge of this Shelf. Until recently, little was known of the physical nature of these banks, or their ecology.Environmental management of petroleum exploration and development activities in the area is required to avoid potentially impacting the surrounding environment. Accurate information on ecological systems is therefore required in order to design detailed Environmental Management Plans which aim to minimise impacts and protect the environment.BHP Petroleum and Woodside Offshore Petroleum, as operators of permits in the area, independently conducted baseline environmental investigations. This information was exchanged, and the cooperative effort between BHPP and Woodside resulted in a significantly improved environmental resource database, which will aid in the planning and implementation of effective environmental management of petroleum operations.The studies included:Accurate bathymetric surveys to determine the geomorphology of the banks.Acquisition of side-scan sonar for interpretation of substrate features and the preparation of preliminary habitat maps.Remotely Operated Vehicle (ROV) surveys to ground truth habitats, and to determine their distribution and species composition.Grab and drop-core sampling to validate ROV film and provide material for chemical and physical analysis.Collecting current data, to aid in the formulation of management strategies for the disposal of drilling discharges and for oil-spill contingency planning.Deep-water benthic trawling to determine the abundance and composition of epi-benthic macrofauna.The main conclusions were that submerged banks are reef-systems that have variable density of coral cover, which are dependant on depth (light intensity), and substrate type. Thirty metres is assumed to be the maximum depth for reef-flat coral growth. The outer rims of the banks support the highest density of coral growth, probably due to the prevailing strong currents which provide greater feeding opportunities and which maintain bare substrate suitable for colonisation. Bank slopes may support a moderate density of coral cover to 60 m. Where conditions are less favourable for coral growth, reef-flats support the macro-algae assemblages dominated by the coralline alga Halimeda, which contributes between 10–60 per cent substrate cover.Deep-water benthic habitats (>300m) support a low-abundance epi-benthic macrofauna.
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Parris, Darren J., Rohan M. Brooker, Michael A. Morgan, Danielle L. Dixson e Frank J. Stewart. "Whole gut microbiome composition of damselfish and cardinalfish before and after reef settlement". PeerJ 4 (31 de agosto de 2016): e2412. http://dx.doi.org/10.7717/peerj.2412.
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The Pomacentridae (damselfish) and Apogonidae (cardinalfish) are among the most common fish families on coral reefs and in the aquarium trade. Members of both families undergo a pelagic larvae phase prior to settlement on the reef, where adults play key roles in benthic habitat structuring and trophic interactions. Fish-associated microbial communities (microbiomes) significantly influence fish health and ecology, yet little is known of how microbiomes change with life stage. We quantified the taxonomic (16S rRNA gene) composition of whole gut microbiomes from ten species of damselfish and two species of cardinalfish from Lizard Island, Australia, focusing specifically on comparisons between pelagic larvae prior to settlement on the reef versus post-settlement juvenile and adult individuals. On average, microbiome phylogenetic diversity increased from pre- to post-settlement, and was unrelated to the microbial composition in the surrounding water column. However, this trend varied among species, suggesting stochasticity in fish microbiome assembly. Pre-settlement fish were enriched with bacteria of the Endozoicomonaceae, Shewanellaceae, and Fusobacteriaceae, whereas settled fish harbored higher abundances of Vibrionaceae and Pasteurellaceae. Several individual operational taxonomic units, including ones related toVibrio harveyi,Shewanella sp., and unculturedEndozoicomonasbacteria, were shared between both pre and post-settlement stages and may be of central importance in the intestinal niche across development. Richness of the core microbiome shared among pre-settlement fish was comparable to that of settled individuals, suggesting that changes in diversity with adulthood are due to the acquisition or loss of host-specific microbes. These results identify a key transition in microbiome structure across host life stage, suggesting changes in the functional contribution of microbiomes over development in two ecologically dominant reef fish families.
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Büscher, Janina V., Max Wisshak, Armin U. Form, Jürgen Titschack, Kerstin Nachtigall e Ulf Riebesell. "In situ growth and bioerosion rates of Lophelia pertusa in a Norwegian fjord and open shelf cold-water coral habitat". PeerJ 7 (24 de setembro de 2019): e7586. http://dx.doi.org/10.7717/peerj.7586.
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Coral reef resilience depends on the balance between carbonate precipitation, leading to reef growth, and carbonate degradation, for example, through bioerosion. Changes in environmental conditions are likely to affect the two processes differently, thereby shifting the balance between reef growth and degradation. In cold-water corals estimates of accretion-erosion processes in their natural habitat are scarce and solely live coral growth rates were studied with regard to future environmental changes in the laboratory so far, limiting our ability to assess the potential of cold-water coral reef ecosystems to cope with environmental changes. In the present study, growth rates of the two predominant colour morphotypes of live Lophelia pertusa as well as bioerosion rates of dead coral framework were assessed in different environmental settings in Norwegian cold-water coral reefs in a 1-year in situ experiment. Net growth (in weight gain and linear extension) of live L. pertusa was in the lower range of previous estimates and did not significantly differ between inshore (fjord) and offshore (open shelf) habitats. However, slightly higher net growth rates were obtained inshore. Bioerosion rates were significantly higher on-reef in the fjord compared to off-reef deployments in- and offshore. Besides, on-reef coral fragments yielded a broader range of individual growth and bioerosion rates, indicating higher turnover in live reef structures than off-reef with regard to accretion–bioerosion processes. Moreover, if the higher variation in growth rates represents a greater variance in (genetic) adaptations to natural environmental variability in the fjord, inshore reefs could possibly benefit under future ocean change compared to offshore reefs. Although not significantly different due to high variances between replicates, growth rates of orange branches were consistently higher at all sites, while mortality was statistically significantly lower, potentially indicating higher stress-resistance than the less pigmented white phenotype. Comparing the here measured rates of net accretion of live corals (regardless of colour morphotype) with net erosion of dead coral framework gives a first estimate of the dimensions of both processes in natural cold-water coral habitats, indicating that calcium carbonate loss through bioerosion amounts to one fifth to one sixth of the production rates by coral calcification (disregarding accretion processes of other organisms and proportion of live and dead coral framework in a reef). With regard to likely accelerating bioerosion and diminishing growth rates of corals under ocean acidification, the balance of reef accretion and degradation may be shifted towards higher biogenic dissolution in the future.
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Renegar, D. Abigail, Paul Schuler, Nicholas Turner, Richard Dodge, Bernhard Riegl, Anthony Knap, Gopal Bera, Ronan Jézéquel e Bradford Benggio. "TROPICS FIELD STUDY (PANAMA), 32-YEAR SITE VISIT: OBSERVATIONS AND CONCLUSIONS FOR NEAR SHORE DISPERSANT USE NEBA AND TRADEOFFS". International Oil Spill Conference Proceedings 2017, n.º 1 (1 de maio de 2017): 3030–50. http://dx.doi.org/10.7901/2169-3358-2017.1.3030.
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ABSTRACT (#2017-141) The Tropical Oil Pollution Investigations in Coastal Systems (TROPICS) experiment initiated in 1984 on the Caribbean coast of Panama has become one of the most comprehensive field experiments examining effects of oil exposure to a combination of tropical marine reef, seagrass, and mangrove communities. The experimental dosage was chosen to simulate a severe but realistic spill scenario so that results could be useful in decisions about the extent to which dispersants reduced or exacerbated the effects of an oil spill on tropical environments of mangroves, seagrasses, and corals. Research has been conducted in the area prior to and 30+ years following exposure to evaluate long term effects. In July 2016, an international research team revisited the TROPICS field sites. In previous data collection visits, visual observations and core samples of the mangrove substrate at the non-treated (Oil only) site revealed the presence of oil. This “trapped” oil also apparently resulted in lower recovery rates for mangroves in that site. Of particular interest in the 2016 revisit was to determine the presence/non-presence of oil in core samples via new petroleum biomarker triple quadrupole mass spectrometry technology. Additionally, data collection and observations of the extent, diversity, and health of the shallow coral reefs, seagrass, and mangroves were conducted at the three sites. The focus was on the initial disruption and recovery of the study ecosystem over 32 years from the original dosing with crude oil or dispersed crude oil. Analysis qualitatively compared the 2016 results to 1984 pre-spill and post-spill conditions of each site. This paper discusses the results of the 2016 TROPICS study site revisit and conclusions for oil spill preparedness and response, particularly as it applies to the trade-offs for the use of dispersants in near shore tropical marine ecosystems.
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Braverman, Irus. "Shifting baselines in coral conservation". Environment and Planning E: Nature and Space 3, n.º 1 (5 de novembro de 2019): 20–39. http://dx.doi.org/10.1177/2514848619882560.
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Reef-building corals are increasingly exposed to warming ocean temperatures. Their immediate response to this rise in temperature is to expel their symbiotic algae and turn white, or bleach. It is mainly for these reasons that corals have been perceived by scientists as both a sign and a measure of the imminent catastrophe facing life in the oceans and, subsequently, on earth. To measure coral decline across space and time, coral scientists have come up with maps, indexes, and color-coded representations. Yet they soon realized that what they regard as today’s healthy reef is, in fact, yesterday’s depleted reef. This problem, referred to as the shifting baselines syndrome, renders most comparisons across time difficult and frustrates the ability to predict the future. The problem is exacerbated in the context of oceans, and further yet in the context of coral reefs, because of the lack of reliable historical records. In fact, many of the coral scientists I have interviewed perceive shifting baselines as one of the key challenges facing coral conservation scientists and managers in their attempts to accurately calculate coral decline—a project that is typically deemed necessary for effective management policies and restoration practices. My article will critically explore the application of, and the assumptions behind, the shifting baselines concept in the context of reef coral science. Specifically, I will draw on interviews with coral scientists to describe the practices and devices embedded in the creation of baselines for corals and, finally, I will explore how certain scientists are challenging the conceptions of nature and time that underlie their operations.
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Daly, R., JD Filmalter, LR Peel, BQ Mann, JSE Lea, CR Clarke e PD Cowley. "Ontogenetic shifts in home range size of a top predatory reef-associated fish (Caranx ignobilis): implications for conservation". Marine Ecology Progress Series 664 (15 de abril de 2021): 165–82. http://dx.doi.org/10.3354/meps13654.
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Defining the home range of vulnerable species is critical for designing effective spatial management strategies. However, animal home ranges often change with ontogeny, and quantifying the associated temporal and spatial changes is particularly challenging for mobile marine species. Here, we investigated how the space use of a top predatory reef-associated fish (giant trevally Caranx ignobilis) scales with body size. Fish were tagged with acoustic transmitters and passively tracked for >3 yr at a tropical island and atoll in the Republic of Seychelles. A sheltered atoll environment was critical for juvenile fish (<60 cm fork length, FL) that exhibited a shift in home range location and area as they matured into adults. Small (60-100 cm FL) and large (>100 cm FL) adult fish appeared to favour shallow coral reefs and associated reef drop offs whilst sharing a similar core home range location. Large adult fish utilized a greater diversity of habitat types and had significantly (p < 0.05) greater annual dispersal distances (mean = 35.29 km, max = 91.32 km) than small adults (mean = 13.72 km, max = 21.55 km). Additionally, the home range of large adults (mean = 209.74 km2) was significantly (p < 0.05) larger than that of juveniles (mean = 38.73 km2) and small adults (77.32 km2) and there was a significant (p = 0.02) relationship between fish length and home range size. Furthermore, tagged fish took up to 34 mo (mean = 18.54 mo) to utilize the full extent of their home range. The habitat shift and expansion in home range size throughout ontogeny should be taken into account when designing effective spatial management plans for C. ignobilis.
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Kleinen, T., V. Brovkin e G. Munhoven. "Carbon cycle dynamics during recent interglacials". Climate of the Past Discussions 11, n.º 3 (20 de maio de 2015): 1945–83. http://dx.doi.org/10.5194/cpd-11-1945-2015.
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Abstract. Trends in the atmospheric concentration of CO2 during three recent interglacials, the Holocene, the Eemian and Marine Isotope Stage (MIS) 11, are investigated using an Earth system Model of Intermediate Complexity, which we extended with modules to dynamically determine two slow carbon cycle processes – peat accumulation and shallow-water CaCO3 sedimentation (coral reef formation). For all three interglacials, model simulations considering peat accumulation and shallow water CaCO3 sedimentation substantially improve the agreement between model results and ice core CO2 reconstructions in comparison to a carbon cycle setup neglecting these processes. This enables us to model the trends in atmospheric CO2, with modelled trends similar to the ice core data, forcing the model only with orbital and sea level changes. During the Holocene, anthropogenic CO2 emissions are required to match the observed rise in atmospheric CO2 after 3 ka BP, but are not relevant before this time. Therefore our model experiments show for the first time how the CO2 evolution during the Holocene and two recent interglacials can be explained consistently using an identical model setup.
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Babcock, R. C., R. D. Pillans e W. A. Rochester. "Environmental and individual effects on the behaviour and spawning movements of Lethrinus nebulosus on a coral reef". Marine and Freshwater Research 68, n.º 8 (2017): 1422. http://dx.doi.org/10.1071/mf16194.
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Spatial management of fish populations can potentially be optimised by incorporating responses to environmental variables, such as diel, tidal, lunar and seasonal factors, but individual variability in habitat use and behaviour may complicate such efforts. Acoustic tagging and tracking of 84 Lethrinus nebulosus in the Ningaloo Marine Park indicated that sizes of individual habitat utilisation kernels were similar across diel and tidal cycles, but varied greatly among individuals. Clearly differentiated diel and tidal habitat use patterns were evident in significant proportions of individuals, particularly in relation to tidal phase. For the majority of residents, home-range sizes were reasonably stable over periods of 2–4 years, but in some cases core areas did shift over time. At seasonal time scales, peaks of seasonal activity and home range area were recorded during spawning season (October–December). Long-distance return migrations to spawning locations were observed that were among the longest observed for any reef fish (over 130km). Suspected spawning-related movements were recorded almost exclusively in fish >500-mm fork length, and were semilunar, following quarter moons in October–December. Significant individual-level variability in movement and habitat use patterns, evident across multiple temporal scales, has important implications for the management of L. nebulosus populations.
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Bellantuono, Anthony J., Ove Hoegh-Guldberg e Mauricio Rodriguez-Lanetty. "Resistance to thermal stress in corals without changes in symbiont composition". Proceedings of the Royal Society B: Biological Sciences 279, n.º 1731 (5 de outubro de 2011): 1100–1107. http://dx.doi.org/10.1098/rspb.2011.1780.
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Discovering how corals can adjust their thermal sensitivity in the context of global climate change is important in understanding the long-term persistence of coral reefs. In this study, we showed that short-term preconditioning to higher temperatures, 3°C below the experimentally determined bleaching threshold, for a period of 10 days provides thermal tolerance for the symbiosis stability between the scleractinian coral, Acropora millepora and Symbiodinium . Based on genotypic analysis, our results indicate that the acclimatization of this coral species to thermal stress does not come down to simple changes in Symbiodinium and/or the bacterial communities that associate with reef-building corals. This suggests that the physiological plasticity of the host and/or symbiotic components appears to play an important role in responding to ocean warming. The further study of host and symbiont physiology, both of Symbiodinium and prokaryotes, is of paramount importance in the context of global climate change, as mechanisms for rapid holobiont acclimatization will become increasingly important to the long-standing persistence of coral reefs.
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Nurhidayat, Iwan, Rustam Rustam e Abdul Rauf. "KONDISI TERUMBU KARANG DI PERAIRAN LIUKANG TANGAYA KABUPATEN PANGKAJENE DAN KEPULAUAN". Jurnal Pendidikan Teknologi Pertanian 5, n.º 1 (10 de fevereiro de 2019): 41. http://dx.doi.org/10.26858/jptp.v5i1.8193.
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Coral reef is one of the most important ecosystem in marine environment. With high biodiversity and productivity as one of their characteristic makes coral reef value in nature regulation cannot be replaced. This study held from July until October 2018. The aim of this study is to understand coral reefs in Liukang Tangaya waters. Data collection using Underwater Photo Transect method. The result are, from 15 observation station show that coral reefs in Liukang Tangaya in damaged condition with average of live coral is 18.91% with the main cause come from destructive fishing.
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Parsons, Karla M., e Carlton E. Brett. "Patterns of epibiont coverage and succession on mollusks from St. Croix, U.S. Virgin Islands". Paleontological Society Special Publications 6 (1992): 229. http://dx.doi.org/10.1017/s2475262200007899.
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Patterns of epibiont coverage are potentially useful tools in the determination of modern and ancient sedimentation rates as well as life habits of host organisms. A study was conducted to characterize patterns of epibiont settlement in various tropical environments and substrate types. Settling plates of clean aragonite shell were placed in six carbonate environments (beach, grass bed, bioturbated sand flat, back reef, forereef, and muddy bay) on St. Croix to document successional trends and timing of infestation by preservable, calcareous epibionts. Coralline algae were first to settle on freshly exposed substrate (within one week), followed by the foraminiferan Planorbulina and serpulid/spirorbid worm tubes. This successional order of epibiont encrustation is proposed as a measure of the length of time a shell has been exposed.The results of this experiment were compared to epibiont patterns on naturally occurring substrates from the same environments. Because the study areas were from essentially the same reef-lagoon system, all sites were exposed to a common pool of encrusting organisms. Of primary interest were differences in encrustation on 1) varying host species, 2) rough- vs. smooth-shell surfaces, 3) infaunal vs. epifaunal shells, 4) substrates of different size, and 5) gastropods vs. bivalves. In addition, the preservability of these patterns was examined on mollusks sampled within Holocene reef cores from St. Croix.Few preferences of epibionts for given shell-host species were noted. However, in lagoon grass-bed areas, epifaunal gastropods consistently showed greater coverage by late-stage encrusters than did infaunal bivalves. Within any environment, epibionts preferentially settled on rough substrates over smooth (e.g. heavily ribbed Codakia were more encrusted than smooth Tellina). Also, bivalve interiors were less encrusted than exteriors. While neither the interior nor exterior of these infaunal bivalves is likely to be encrusted during life, the interior of both species remained less encrusted, perhaps controlled by the smooth nature of the shell interior.Differences in both the abundance and diversity of epibiont faunas were noted between substrates of different size. Epibiont faunas from mollusk shells smaller than 8 cm had fewer epibiont species than did coral substrates at least 15 cm across. The foram Gypsina, a white sheet-like encruster, and several species of bryozoa, all late-stage encrusters, were more successful on larger substrates from the same environments. This may be controlled by the successional patterns described above. Larger substrates were presumably exposed longer and thus acquired a higher diversity of encrusting species, thereby allowing some encrusters to spread over more area. Size differences exerted more control on epibiont coverage than did substrate type (i.e. coral vs. mollusk). The primary control of epibiont coverage, therefore, was the length of time a shell was exposed. Substrate-selective patterns were not as great as those occurring between environments.Shells recovered from reef cores looked very much like those described from the reef surface. The occurrence of mollusk remains throughout the cores, along with a 5700±70 ybp radiocarbon date from a Chione valve from the bottom of one core, indicates that these are not simply recent shells that have fallen into the reef interior. Therefore, epibiont coverage has high potential for being preserved on shells caught up in the accreting reef.
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Kleinen, Thomas, Victor Brovkin e Guy Munhoven. "Modelled interglacial carbon cycle dynamics during the Holocene, the Eemian and Marine Isotope Stage (MIS) 11". Climate of the Past 12, n.º 12 (29 de novembro de 2016): 2145–60. http://dx.doi.org/10.5194/cp-12-2145-2016.
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Abstract. Trends in the atmospheric concentration of CO2 during three recent interglacials – the Holocene, the Eemian and Marine Isotope Stage (MIS) 11 – are investigated using an earth system model of intermediate complexity, which we extended with process-based modules to consider two slow carbon cycle processes – peat accumulation and shallow-water CaCO3 sedimentation (coral reef formation). For all three interglacials, model simulations considering peat accumulation and shallow-water CaCO3 sedimentation substantially improve the agreement between model results and ice core CO2 reconstructions in comparison to a carbon cycle set-up neglecting these processes. This enables us to model the trends in atmospheric CO2, with modelled trends similar to the ice core data, forcing the model only with orbital and sea level changes. During the Holocene, anthropogenic CO2 emissions are required to match the observed rise in atmospheric CO2 after 3 ka BP but are not relevant before this time. Our model experiments show a considerable improvement in the modelled CO2 trends by the inclusion of the slow carbon cycle processes, allowing us to explain the CO2 evolution during the Holocene and two recent interglacials consistently using an identical model set-up.
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Yu, Ke-Fu, Jian-Xin Zhao, Pin-Xian Wang, Qi Shi, Qing-Shan Meng, Kenneth D. Collerson e Tung-Sheng Liu. "High-precision TIMS U-series and AMS 14C dating of a coral reef lagoon sediment core from southern South China Sea". Quaternary Science Reviews 25, n.º 17-18 (setembro de 2006): 2420–30. http://dx.doi.org/10.1016/j.quascirev.2006.01.027.
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Lin, Senjie, Liying Yu e Huan Zhang. "Transcriptomic Responses to Thermal Stress and Varied Phosphorus Conditions in Fugacium kawagutii". Microorganisms 7, n.º 4 (2 de abril de 2019): 96. http://dx.doi.org/10.3390/microorganisms7040096.
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Coral reef-associated Symbiodiniaceae live in tropical and oligotrophic environments and are prone to heat and nutrient stress. How their metabolic pathways respond to pulses of warming and phosphorus (P) depletion is underexplored. Here, we conducted RNA-seq analysis to investigate transcriptomic responses to thermal stress, phosphate deprivation, and organic phosphorus (OP) replacement in Fugacium kawagutii. Using dual-algorithm (edgeR and NOIseq) to remedy the problem of no replicates, we conservatively found 357 differentially expressed genes (DEGs) under heat stress, potentially regulating cell wall modulation and the transport of iron, oxygen, and major nutrients. About 396 DEGs were detected under P deprivation and 671 under OP utilization, both mostly up-regulated and potentially involved in photosystem and defensome, despite different KEGG pathway enrichments. Additionally, we identified 221 genes that showed relatively stable expression levels across all conditions (likely core genes), mostly catalytic and binding proteins. This study reveals a wide range of, and in many cases previously unrecognized, molecular mechanisms in F. kawagutii to cope with heat stress and phosphorus-deficiency stress. Their quantitative expression dynamics, however, requires further verification with triplicated experiments, and the data reported here only provide clues for generating testable hypotheses about molecular mechanisms underpinning responses and adaptation in F. kawagutii to temperature and nutrient stresses.
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Schlaff, A., P. Menéndez, M. Hall, M. Heupel, T. Armstrong e C. Motti. "Acoustic tracking of a large predatory marine gastropod, Charonia tritonis, on the Great Barrier Reef". Marine Ecology Progress Series 642 (28 de maio de 2020): 147–61. http://dx.doi.org/10.3354/meps13291.
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Crown-of-thorns starfish Acanthaster planci (COTS) outbreaks are a major cause of coral cover loss on the Great Barrier Reef (GBR), with manual culling having only localised success. The endangered giant triton snail Charonia tritonis is a natural predator of COTS, although aquarium and field observations indicate the intensity of direct predation may be inadequate to significantly mediate outbreaks. However, their mere presence can elicit a chemically induced sensory behavioural response which may suppress COTS populations when in non-outbreak status. While there is increasing knowledge of the sensory biology of both species, little is known regarding giant triton snail numbers on the GBR or about how they move and occupy space, making it difficult to determine their true zone of influence and thus their capacity to disrupt COTS behaviour. We used passive acoustic telemetry to establish short-term activity space and movement patterns of giant triton snails on the GBR. Individuals were tracked for up to 41 d, were observed to travel 234.24 m d-1, with a mean total cumulative distance travelled at night (1923.19 m) nearly double that observed during the day (1014.84 m). These distances encompass those reported for COTS (10.3 m d-1) and align with COTS nocturnal behaviour. Space utilisation distributions (UDs) revealed a mean (±SD) home range of 1179.40 ± 659.40 m2 (95% UD) and a core area of 195.68 ± 141.31 m2 (50% UD). Revealing the short-term movement patterns of this natural COTS predator within a reef environment advances knowledge of its spatial ecology and will provide information for its future conservation and for COTS management efforts.
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van Bleijswijk, J. D. L., C. Whalen, G. C. A. Duineveld, M. S. S. Lavaleye, H. J. Witte e F. Mienis. "Microbial assemblages on a cold-water coral mound at the SE Rockall Bank (NE Atlantic): interactions with hydrography and topography". Biogeosciences Discussions 12, n.º 2 (22 de janeiro de 2015): 1509–42. http://dx.doi.org/10.5194/bgd-12-1509-2015.
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Abstract. This study shows the microbial community composition over Haas Mound, one of the most prominent cold-water coral mounds of the Logachev Mound Province (Rockall Bank, NE Atlantic), outlining distribution patterns both vertically from the seafloor to the water column and laterally across the mound and coupling this to mound topography and hydrography. Samples were collected in 2012 and 2013 from biotopes that were partially chosen based on high definition video surveys that were conducted prior to sampling and included overlaying water (400 m depth and 5+10 m above the bottom (m ab)) collected with a CTD/Rosette system and near-bottom water, sediment, Lophelia pertusa mucus, and L. pertusa skeleton samples collected with a box-core. Furthermore, temperature and current measurements were obtained at two sites at the summit and foot of Haas Mound to study near-bed hydrodynamic conditions. Community composition was determined by next generation Roche 454 sequencing yielding high-resolution records of 16 S rRNA genotypes, improving our understanding of deep-sea microbial consortia. With the methods we employed we were able to report for the first time Archaea in association with L. pertusa. The pattern of similarities between samples visualized by multi-dimensional scaling (MDS), indicates a strong link between the distribution of microbes and specific biotopes. All biotopes share a number of taxa, but biotopes are distinct on basis of relative abundances and a small number of unique taxa. Similarity in microbes indicates that water is well-mixed at 400 m depth, but less so at 5 + 10 m above the bottom, where microbial communities differed between summit, slope and off mound. Even more variability was observed in the near-bottom water samples, which group according to sampling station. Likely the coral framework prevents the near-bottom water in between the branches to be vigorously mixed with the water overlaying the reef. The microbial consortium on Haas Mound appears strongly linked with the surrounding environment, making cold-water coral communities sensitive to outside environmental influences.
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KATILI, ABUBAKAR SIDIK, RAMLI UTINA, YOWAN TAMU e ELYA NUSANTARI. "Management of coastal biodiversity based on social-cultural values in constructing conservation character education". Biodiversitas Journal of Biological Diversity 19, n.º 5 (21 de setembro de 2018): 1763–68. http://dx.doi.org/10.13057/biodiv/d190524.
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Katili AS, Utina R, Tamu Y, Nusantari E. 2018. Management of coastal biodiversity based on social-cultural values in constructing conservation character education. Biodiversitas 19: 1763-1768. Coastal biodiversity is quite high including coral reef, mangrove, seagrass, and fishery resources. Management of coastal biodiversity can be conducted interdisciplinary covering various aspects. Four main aspects can be integrated, i.e., physical-biodiversity, social-cultural, character education, and conservation. This present study aimed to describe: coastal biodiversity in Gorontalo Province, Indonesia community’s social-cultural value and local wisdom embodying conservation character of the coastal ecosystem, and character education of coastal ecosystem biodiversity in primary school by learning with a prototype of conservation character-based materials. Specifically, the present study aimed to construct the conservation character education based on social-cultural values. Data were analyzed with descriptive qualitative method by comparing and referring to findings from the previous studies. The procedure used in this research was four-D, i.e., (i) Define stage; by doing the identification and exploration of the coastal biodiversity potential. The methods used in this stage was exploration survey method. Focused group discussions were conducted with coastal communities to identify social-cultural values and local wisdom and to analyze the core and basic competence of learners by examining the tools of the lesson and determining the competence. (ii) Design stage; by designing a prototype of learning material to construct the conservation character for learners. (iii) Development stage; by validating the prototype of learning material for constructing the conservation character for the learner. (iv) Dissemination stage, by doing seminars and information dissemination on a prototype of learning material to construct the conservation character. The results showed that in Gorontalo, there were three components of the coastal ecosystem which included mangrove, seagrass, and coral reef. The communities in the coastal area of Gorontalo were prominent in their strengthened social-cultural roots taking the form of ecological awareness. The community in coastal area possessed local knowledge of the natural resources, e.g., plants and animals, and local attribution of such resources in the local language. The conservation character-education based on social-cultural values, specifically local wisdom, is the most appropriate education model to encourage the pattern of biodiversity coastal ecosystem management. Conservation character education was highly relevant to life-enhancing skills, based on the empowerment of skills and coastal biodiversity potential in each region.
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Bozec, Yves-Marie, Shay O'Farrell, J. Henrich Bruggemann, Brian E. Luckhurst e Peter J. Mumby. "Tradeoffs between fisheries harvest and the resilience of coral reefs". Proceedings of the National Academy of Sciences 113, n.º 16 (4 de abril de 2016): 4536–41. http://dx.doi.org/10.1073/pnas.1601529113.
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Many countries are legally obliged to embrace ecosystem-based approaches to fisheries management. Reductions in bycatch and physical habitat damage are now commonplace, but mitigating more sophisticated impacts associated with the ecological functions of target fisheries species are in their infancy. Here we model the impacts of a parrotfish fishery on the future state and resilience of Caribbean coral reefs, enabling us to view the tradeoff between harvest and ecosystem health. We find that the implementation of a simple and enforceable size restriction of >30 cm provides a win:win outcome in the short term, delivering both ecological and fisheries benefits and leading to increased yield and greater coral recovery rate for a given harvest rate. However, maintaining resilient coral reefs even until 2030 requires the addition of harvest limitations (<10% of virgin fishable biomass) to cope with a changing climate and induced coral disturbances, even in reefs that are relatively healthy today. Managing parrotfish is not a panacea for protecting coral reefs but can play a role in sustaining the health of reefs and high-quality habitat for reef fisheries.
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Stanley, George D., e John-Paul Zonneveld. "The occurrence of the hydrozoan genus Cassianastraea from Upper Triassic (Carnian) rocks of Williston Lake, British Columbia, Canada". Journal of Paleontology 85, n.º 1 (janeiro de 2011): 29–31. http://dx.doi.org/10.1666/10-044.1.
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Cassianastraea is an enigmatic colonial Triassic cnidarian first described as a coral but subsequently referred to the Hydrozoa. We report here the first occurrence in Canada of fossils we designate as Cassianastraea sp. from the Williston Lake region of British Columbia. The specimens come from older collections of the Geological Survey of Canada, collected in Upper Triassic (Carnian) strata assigned to either the Ludington or Baldonnel Formations. While well known in reef associations of the former Tethys region, Cassianiastraea is relatively rare in North America. The Carnian Baldonnel Formation contains the earliest coral reefs from the North American craton and we suspect that Cassianastraea sp. also came from this reef association.
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PENNY, AMELIA, ANDRÉ DESROCHERS e BJÖRN KRÖGER. "METAZOAN REEF CONSTRUCTION IN A MIDDLE ORDOVICIAN SEASCAPE: A CASE STUDY FROM THE MINGAN ARCHIPELAGO, QUEBEC". PALAIOS 35, n.º 8 (27 de agosto de 2020): 327–41. http://dx.doi.org/10.2110/palo.2020.010.
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ABSTRACT The Ordovician (485–444 Ma) saw a global shift from microbial- to skeletal-dominated reefs, and the rise of corals and bryozoans as important reef-builders. Hypothetically, increasingly morphologically diverse and abundant reef-building metazoans increased spatial habitat heterogeneity in reef environments, an important component of reefs' capacity to support diverse communities. Quantifying the spatial scale and extent of this heterogeneity requires three-dimensional exposures of well-preserved reefs whose composition and spatial arrangement can be measured. The Darriwilian (c. 467–458 Ma) carbonate sequence of the Mingan Archipelago, Quebec, presents such exposures, and also provides an opportunity to establish how the distribution of skeletal-dominated metazoan reefs contributed to, and was influenced by, seafloor relief. This study includes two transects through a 200–300 m wide paleo-reef belt, which developed along a rocky paleo-coast line. The reefs are typically micrite-rich, meter-scale mounds, locally forming larger complexes. Here, we present quantitative evaluations of the composition of these reefs, and detailed mapping of reef distributions. There is high compositional heterogeneity between reefs at spatial scales ranging from meters to kilometers, contributed by differences in the volumetric contribution of skeletal material to the reef core, and in the identity of the dominant reef-builders. We suggest that the abundance and morphological diversity of Middle Ordovician reef building metazoans made them important contributors to environmental and substrate heterogeneity, likely enhancing the diversity of reef-dwelling communities.
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Enríquez, Susana, Eugenio R. Méndez, Ove Hoegh-Guldberg e Roberto Iglesias-Prieto. "Key functional role of the optical properties of coral skeletons in coral ecology and evolution". Proceedings of the Royal Society B: Biological Sciences 284, n.º 1853 (26 de abril de 2017): 20161667. http://dx.doi.org/10.1098/rspb.2016.1667.
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Multiple scattering of light on coral skeleton enhances light absorption efficiency of coral symbionts and plays a key role in the regulation of their internal diffuse light field. To understand the dependence of this enhancement on skeleton meso- and macrostructure, we analysed the scattering abilities of naked coral skeletons for 74 Indo-Pacific species. Sensitive morphotypes to thermal and light stress, flat-extraplanate and branching corals, showed the most efficient structures, while massive-robust species were less efficient. The lowest light-enhancing scattering abilities were found for the most primitive colonial growth form: phaceloid. Accordingly, the development of highly efficient light-collecting structures versus the selection of less efficient but more robust holobionts to cope with light stress may constitute a trade-off in the evolution of modern symbiotic scleractinian corals, characterizing two successful adaptive solutions. The coincidence of the most important structural modifications with epitheca decline supports the importance of the enhancement of light transmission across coral skeleton in modern scleractinian diversification, and the central role of these symbioses in the design and optimization of coral skeleton. Furthermore, the same ability that lies at the heart of the success of symbiotic corals as coral-reef-builders can also explain the ‘Achilles's heel’ of these symbioses in a warming ocean.