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Sample records for barrier reef corals

  1. Coral reef community composition in the context of disturbance history on the Great Barrier Reef, Australia.

    Science.gov (United States)

    Graham, Nicholas A J; Chong-Seng, Karen M; Huchery, Cindy; Januchowski-Hartley, Fraser A; Nash, Kirsty L

    2014-01-01

    Much research on coral reefs has documented differential declines in coral and associated organisms. In order to contextualise this general degradation, research on community composition is necessary in the context of varied disturbance histories and the biological processes and physical features thought to retard or promote recovery. We conducted a spatial assessment of coral reef communities across five reefs of the central Great Barrier Reef, Australia, with known disturbance histories, and assessed patterns of coral cover and community composition related to a range of other variables thought to be important for reef dynamics. Two of the reefs had not been extensively disturbed for at least 15 years prior to the surveys. Three of the reefs had been severely impacted by crown-of-thorns starfish outbreaks and coral bleaching approximately a decade before the surveys, from which only one of them was showing signs of recovery based on independent surveys. We incorporated wave exposure (sheltered and exposed) and reef zone (slope, crest and flat) into our design, providing a comprehensive assessment of the spatial patterns in community composition on these reefs. Categorising corals into life history groupings, we document major coral community differences in the unrecovered reefs, compared to the composition and covers found on the undisturbed reefs. The recovered reef, despite having similar coral cover, had a different community composition from the undisturbed reefs, which may indicate slow successional processes, or a different natural community dominance pattern due to hydrology and other oceanographic factors. The variables that best correlated with patterns in the coral community among sites included the density of juvenile corals, herbivore fish biomass, fish species richness and the cover of macroalgae. Given increasing impacts to the Great Barrier Reef, efforts to mitigate local stressors will be imperative to encouraging coral communities to persist into

  2. Coral reef community composition in the context of disturbance history on the Great Barrier Reef, Australia.

    Directory of Open Access Journals (Sweden)

    Nicholas A J Graham

    Full Text Available Much research on coral reefs has documented differential declines in coral and associated organisms. In order to contextualise this general degradation, research on community composition is necessary in the context of varied disturbance histories and the biological processes and physical features thought to retard or promote recovery. We conducted a spatial assessment of coral reef communities across five reefs of the central Great Barrier Reef, Australia, with known disturbance histories, and assessed patterns of coral cover and community composition related to a range of other variables thought to be important for reef dynamics. Two of the reefs had not been extensively disturbed for at least 15 years prior to the surveys. Three of the reefs had been severely impacted by crown-of-thorns starfish outbreaks and coral bleaching approximately a decade before the surveys, from which only one of them was showing signs of recovery based on independent surveys. We incorporated wave exposure (sheltered and exposed and reef zone (slope, crest and flat into our design, providing a comprehensive assessment of the spatial patterns in community composition on these reefs. Categorising corals into life history groupings, we document major coral community differences in the unrecovered reefs, compared to the composition and covers found on the undisturbed reefs. The recovered reef, despite having similar coral cover, had a different community composition from the undisturbed reefs, which may indicate slow successional processes, or a different natural community dominance pattern due to hydrology and other oceanographic factors. The variables that best correlated with patterns in the coral community among sites included the density of juvenile corals, herbivore fish biomass, fish species richness and the cover of macroalgae. Given increasing impacts to the Great Barrier Reef, efforts to mitigate local stressors will be imperative to encouraging coral

  3. Disturbance and the Dynamics of Coral Cover on the Great Barrier Reef (1995–2009)

    OpenAIRE

    Kate Osborne; Dolman, Andrew M; Burgess, Scott C.; Johns, Kerryn A.

    2011-01-01

    Coral reef ecosystems worldwide are under pressure from chronic and acute stressors that threaten their continued existence. Most obvious among changes to reefs is loss of hard coral cover, but a precise multi-scale estimate of coral cover dynamics for the Great Barrier Reef (GBR) is currently lacking. Monitoring data collected annually from fixed sites at 47 reefs across 1300 km of the GBR indicate that overall regional coral cover was stable (averaging 29% and ranging from 23% to 33% cover ...

  4. Recruitment Variability of Coral Reef Sessile Communities of the Far North Great Barrier Reef

    Science.gov (United States)

    Luter, Heidi M.; Duckworth, Alan R.; Wolff, Carsten W.; Evans-Illidge, Elizabeth; Whalan, Steve

    2016-01-01

    One of the key components in assessing marine sessile organism demography is determining recruitment patterns to benthic habitats. An analysis of serially deployed recruitment tiles across depth (6 and 12 m), seasons (summer and winter) and space (meters to kilometres) was used to quantify recruitment assemblage structure (abundance and percent cover) of corals, sponges, ascidians, algae and other sessile organisms from the northern sector of the Great Barrier Reef (GBR). Polychaetes were most abundant on recruitment titles, reaching almost 50% of total recruitment, yet covered Coral recruitment was very low, with coral reefs. PMID:27049650

  5. Coral bleaching: one disturbance too many for near-shore reefs of the Great Barrier Reef

    Science.gov (United States)

    Thompson, A. A.; Dolman, A. M.

    2010-09-01

    The dynamic nature of coral communities can make it difficult to judge whether a reef system is resilient to the current disturbance regime. To address this question of resilience for near-shore coral communities of the Great Barrier Reef (Australia) a data set consisting of 350 annual observations of benthic community change was compiled from existing monitoring data. These data spanned the period 1985-2007 and were derived from coral reefs within 20 km of the coast. During years without major disturbance events, cover increase of the Acroporidae was much faster than it was for other coral families; a median of 11% per annum compared to medians of less than 4% for other coral families. Conversely, Acroporidae were more severely affected by cyclones and bleaching events than most other families. A simulation model parameterised with these observations indicated that while recovery rates of hard corals were sufficient to compensate for impacts associated with cyclones and crown-of-thorns starfish, the advent of mass bleaching has lead to a significant change in the composition of the community and a rapid decline in hard coral cover. Furthermore, if bleaching events continue to occur with the same frequency and severity as in the recent past, the model predicts that the cover of Acroporidae will continue to decline. Although significant cover of live coral remains on near-shore reefs, and recovery is observed during inter-disturbance periods, it appears that this system will not be resilient to the recent disturbance regime over the long term. Conservation strategies for coral reefs should focus on both mitigating local factors that act synergistically to increase the susceptibility of Acroporidae to climate change while promoting initiatives that maximise the recovery potential from inevitable disturbances.

  6. An observational heat budget analysis of a coral reef, Heron Reef, Great Barrier Reef, Australia

    Science.gov (United States)

    MacKellar, Mellissa C.; McGowan, Hamish A.; Phinn, Stuart R.

    2013-03-01

    Measurements of the surface energy balance, the structure and evolution of the convective atmospheric reef layer (CARL), and local meteorology and hydrodynamics were made during June 2009 and February 2010 at Heron Reef, Australia, to establish the relative partitioning of heating within the water and atmosphere. Horizontal advection was shown to moderate temperature in the CARL and the water, having a cooling influence on the atmosphere, and providing an additional source or sink of energy to the water overlying the reef, depending on tide. The key driver of atmospheric heating was surface sensible heat flux, while heating of the reef water was primarily due to solar radiation, and thermal conduction and convection from the reef substrate. Heating and cooling processes were more defined during winter due to higher sensible and latent heat fluxes and strong diurnal evolution of the CARL. Sudden increases in water temperature were associated with inundation of warmer oceanic water during the flood tide, particularly in winter due to enhanced nocturnal cooling of water overlying the reef. Similarly, cooling of the water over the reef occurred during the ebb tide as heat was transported off the reef to the surrounding ocean. While these results are the first to shed light on the heat budget of a coral reef and overlying CARL, longer-term, systematic measurements of reef thermal budgets are needed under a range of meteorological and hydrodynamic conditions, and across various reef types to elucidate the influence on larger-scale oceanic and atmospheric processes. This is essential for understanding the role of coral reefs in tropical and sub-tropical meteorology; the physical processes that take place during coral bleaching events, and coral and algal community dynamics on coral reefs.

  7. Predicting the location and spatial extent of submerged coral reef habitat in the Great Barrier Reef world heritage area, Australia.

    Directory of Open Access Journals (Sweden)

    Tom Bridge

    Full Text Available AIM: Coral reef communities occurring in deeper waters have received little research effort compared to their shallow-water counterparts, and even such basic information as their location and extent are currently unknown throughout most of the world. Using the Great Barrier Reef as a case study, habitat suitability modelling is used to predict the distribution of deep-water coral reef communities on the Great Barrier Reef, Australia. We test the effectiveness of a range of geophysical and environmental variables for predicting the location of deep-water coral reef communities on the Great Barrier Reef. LOCATION: Great Barrier Reef, Australia. METHODS: Maximum entropy modelling is used to identify the spatial extent of two broad communities of habitat-forming megabenthos phototrophs and heterotrophs. Models were generated using combinations of geophysical substrate properties derived from multibeam bathymetry and environmental data derived from Bio-ORACLE, combined with georeferenced occurrence records of mesophotic coral communities from autonomous underwater vehicle, remotely operated vehicle and SCUBA surveys. Model results are used to estimate the total amount of mesophotic coral reef habitat on the GBR. RESULTS: Our models predict extensive but previously undocumented coral communities occurring both along the continental shelf-edge of the Great Barrier Reef and also on submerged reefs inside the lagoon. Habitat suitability for phototrophs is highest on submerged reefs along the outer-shelf and the deeper flanks of emergent reefs inside the GBR lagoon, while suitability for heterotrophs is highest in the deep waters along the shelf-edge. Models using only geophysical variables consistently outperformed models incorporating environmental data for both phototrophs and heterotrophs. MAIN CONCLUSION: Extensive submerged coral reef communities that are currently undocumented are likely to occur throughout the Great Barrier Reef. High

  8. Sea level record obtained from submerged the Great Barrier Reef coral reefs

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    Yokoyama, Y.; Esat, T. M.; Thompson, W. G.; Thomas, A. L.; Webster, J.; Miyairi, Y.; Matsuzaki, H.; Okuno, J.; Fallon, S.; Braga, J.; Humblet, M.; Iryu, Y.; Potts, D. C.

    2013-12-01

    The last glacial is an interesting time in climate history. The growth and decay of large northern hemisphere ice sheets acting in harmony with major changes in ocean circulation amplified climate variations and resulted in severe and rapid climate swings throughout this time. The variability is not limited to climate but includes rapid, large scale changes in sea level recorded by tropical corals (eg., Yokoyama and Esat, 2011 Oceanography). Research done in the last decade using corals provides a better picture of the climate system, though only a few samples older than 15 ka are available. The Integrated Ocean Drilling Program (IODP) Expedition 325 drilled 34 holes across 17 sites in the Great Barrier Reef, Australia to recover fossil coral reef deposits. We recovered reef materials from water depth to 126 m that ranged in age from 9,000 years to older than 30,000 years ago covering several paleoclimatologically important events, including the Last Glacial Maximum. Two transects separated more than 600 km apart show an identical sea-level history thereby verifying the reliability of the records. Radiometrically dated corals and coralline algae indicate periods of rapid sea-level fluctuation at this time, likely due to complex interactions between ocean currents and ice sheets of the North Atlantic.

  9. Seasonal Dynamical Prediction of Coral Bleaching in the Great Barrier Reef, Australia

    Science.gov (United States)

    Spillman, C. M.; Alves, O.

    2009-05-01

    Sea surface temperature (SST) is now recognised as the primary cause of mass coral bleaching events. Coral bleaching occurs during times of stress, particularly when SSTs exceed the coral colony's tolerance level. Global warming is potentially a serious threat to the future of the world's reef systems with predictions by the international community that bleaching will increase in both frequency and severity. Advance warning of anomalous sea surface temperatures, and thus potential bleaching events, would allow for the implementation of management strategies to minimise reef damage. Seasonal SST forecasts from the coupled ocean-atmosphere model POAMA (Bureau of Meteorology) have skill in the Great Barrier Reef (Australia) several months into the future. We will present model forecasts and probabilistic products for use in reef management, and assess model skill in the region. These products will revolutionise the way in which coral bleaching events are monitored and assessed in the Great Barrier Reef and Australian region.

  10. Cryptofauna of the epilithic algal matrix on an inshore coral reef, Great Barrier Reef

    Science.gov (United States)

    Kramer, M. J.; Bellwood, D. R.; Bellwood, O.

    2012-12-01

    Composed of a collection of algae, detritus, sediment and invertebrates, the epilithic algal matrix (EAM) is an abundant and ubiquitous feature of coral reefs. Despite its prevalence, there is a paucity of information regarding its associated invertebrate fauna. The cryptofaunal invertebrate community of the EAM was quantitatively investigated in Pioneer Bay on Orpheus Island, Great Barrier Reef. Using a vacuum collection method, a diversity of organisms representing 10 different phyla were identified. Crustacea dominated the samples, with harpacticoid copepods being particularly abundant (2025 ± 132 100 cm-2; mean density ± SE). The volume of coarse particulate matter in the EAM was strongly correlated with the abundance of harpacticoid copepods. The estimated biomass of harpacticoid copepods (0.48 ± 0.05 g m-2; wet weight) suggests that this group is likely to be important for reef trophodynamics and nutrient cycling.

  11. Impact Of Coral Structures On Wave Directional Spreading Across A Shallow Reef Flat - Lizard Island, Northern Great Barrier Reef

    Science.gov (United States)

    Leon, J. X.; Baldock, T.; Callaghan, D. P.; Hoegh-guldberg, O.; Mumby, P.; Phinn, S. R.; Roelfsema, C. M.; Saunders, M. I.

    2013-12-01

    Coral reef hydrodynamics operate at several and overlapping spatial-temporal scales. Waves have the most important forcing function on shallow (stress, directly mixing water (temperature and nutrients) and transporting sediments, nutrients and plankton. Reef flats are very effective at dissipating wave energy and providing an important ecosystem service by protecting highly valued shorelines. The effectiveness of reef flats to dissipate wave energy is related to the extreme hydraulic roughness of the benthos and substrate composition. Hydraulic roughness is usually obtained empirically from frictional-dissipation calculations, as detailed field measurements of bottom roughness (e.g. chain-method or profile gauges) is a very labour and time-consuming task. In this study we measured the impact of coral structures on wave directional spreading. Field data was collected during October 2012 across a reef flat on Lizard Island, northern Great Barrier Reef. Wave surface levels were measured using an array of self-logging pressure sensors. A rapid in situ close-range photogrammetric method was used to create a high-resolution (0.5 cm) image mosaic and digital elevation model. Individual coral heads were extracted from these datasets using geo-morphometric and object-based image analysis techniques. Wave propagation was modelled using a modified version of the SWAN model which includes the measured coral structures in 2m by 1m cells across the reef. The approach followed a cylinder drag approach, neglecting skin friction and inertial components. Testing against field data included bed skin friction. Our results show, for the first time, how the variability of the reef benthos structures affects wave dissipation across a shallow reef flat. This has important implications globally for coral reefs, due to the large extent of their area occupied by reef flats, particularly, as global-scale degradation in coral reef health is causing a lowering of reef carbonate production that

  12. Disturbance and the dynamics of coral cover on the Great Barrier Reef (1995-2009.

    Directory of Open Access Journals (Sweden)

    Kate Osborne

    Full Text Available Coral reef ecosystems worldwide are under pressure from chronic and acute stressors that threaten their continued existence. Most obvious among changes to reefs is loss of hard coral cover, but a precise multi-scale estimate of coral cover dynamics for the Great Barrier Reef (GBR is currently lacking. Monitoring data collected annually from fixed sites at 47 reefs across 1300 km of the GBR indicate that overall regional coral cover was stable (averaging 29% and ranging from 23% to 33% cover across years with no net decline between 1995 and 2009. Subregional trends (10-100 km in hard coral were diverse with some being very dynamic and others changing little. Coral cover increased in six subregions and decreased in seven subregions. Persistent decline of corals occurred in one subregion for hard coral and Acroporidae and in four subregions in non-Acroporidae families. Change in Acroporidae accounted for 68% of change in hard coral. Crown-of-thorns starfish (Acanthaster planci outbreaks and storm damage were responsible for more coral loss during this period than either bleaching or disease despite two mass bleaching events and an increase in the incidence of coral disease. While the limited data for the GBR prior to the 1980's suggests that coral cover was higher than in our survey, we found no evidence of consistent, system-wide decline in coral cover since 1995. Instead, fluctuations in coral cover at subregional scales (10-100 km, driven mostly by changes in fast-growing Acroporidae, occurred as a result of localized disturbance events and subsequent recovery.

  13. Congruent patterns of connectivity can inform management for broadcast spawning corals on the Great Barrier Reef.

    Science.gov (United States)

    Lukoschek, Vimoksalehi; Riginos, Cynthia; van Oppen, Madeleine J H

    2016-07-01

    Connectivity underpins the persistence and recovery of marine ecosystems. The Great Barrier Reef (GBR) is the world's largest coral reef ecosystem and managed by an extensive network of no-take zones; however, information about connectivity was not available to optimize the network's configuration. We use multivariate analyses, Bayesian clustering algorithms and assignment tests of the largest population genetic data set for any organism on the GBR to date (Acropora tenuis, >2500 colonies; >50 reefs, genotyped for ten microsatellite loci) to demonstrate highly congruent patterns of connectivity between this common broadcast spawning reef-building coral and its congener Acropora millepora (~950 colonies; 20 reefs, genotyped for 12 microsatellite loci). For both species, there is a genetic divide at around 19°S latitude, most probably reflecting allopatric differentiation during the Pleistocene. GBR reefs north of 19°S are essentially panmictic whereas southern reefs are genetically distinct with higher levels of genetic diversity and population structure, most notably genetic subdivision between inshore and offshore reefs south of 19°S. These broadly congruent patterns of higher genetic diversities found on southern GBR reefs most likely represent the accumulation of alleles via the southward flowing East Australia Current. In addition, signatures of genetic admixture between the Coral Sea and outer-shelf reefs in the northern, central and southern GBR provide evidence of recent gene flow. Our connectivity results are consistent with predictions from recently published larval dispersal models for broadcast spawning corals on the GBR, thereby providing robust connectivity information about the dominant reef-building genus Acropora for coral reef managers. PMID:27085309

  14. Disease outbreaks, bleaching and a cyclone drive changes in coral assemblages on an inshore reef of the Great Barrier Reef

    Science.gov (United States)

    Haapkylä, J.; Melbourne-Thomas, J.; Flavell, M.; Willis, B. L.

    2013-09-01

    Coral disease is a major threat to the resilience of coral reefs; thus, understanding linkages between disease outbreaks and disturbances predicted to increase with climate change is becoming increasingly important. Coral disease surveys conducted twice yearly between 2008 and 2011 at a turbid inshore reef in the central Great Barrier Reef spanned two disturbance events, a coral bleaching event in 2009 and a severe cyclone (cyclone `Yasi') in 2011. Surveys of coral cover, community structure and disease prevalence throughout this 4-yr study provide a unique opportunity to explore cumulative impacts of disturbance events and disease for inshore coral assemblages. The principal coral disease at the study site was atramentous necrosis (AtN), and it primarily affected the key inshore, reef-building coral Montipora aequituberculata. Other diseases detected were growth anomalies, white syndrome and brown band syndrome. Diseases affected eight coral genera, although Montipora was, by far, the genus mostly affected. The prevalence of AtN followed a clear seasonal pattern, with disease outbreaks occurring only in wet seasons. Mean prevalence of AtN on Montipora spp. (63.8 % ± 3.03) was three- to tenfold greater in the wet season of 2009, which coincided with the 2009 bleaching event, than in other years. Persistent wet season outbreaks of AtN combined with the impacts of bleaching and cyclone events resulted in a 50-80 % proportional decline in total coral cover. The greatest losses of branching and tabular acroporids occurred following the low-salinity-induced bleaching event of 2009, and the greatest losses of laminar montiporids occurred following AtN outbreaks in 2009 and in 2011 following cyclone Yasi. The shift to a less diverse coral assemblage and the concomitant loss of structural complexity are likely to have long-term consequences for associated vertebrate and invertebrate communities on Magnetic Island reefs.

  15. Effectiveness of benthic foraminiferal and coral assemblages as water quality indicators on inshore reefs of the Great Barrier Reef, Australia

    Science.gov (United States)

    Uthicke, S.; Thompson, A.; Schaffelke, B.

    2010-03-01

    Although the debate about coral reef decline focuses on global disturbances (e.g., increasing temperatures and acidification), local stressors (nutrient runoff and overfishing) continue to affect reef health and resilience. The effectiveness of foraminiferal and hard-coral assemblages as indicators of changes in water quality was assessed on 27 inshore reefs along the Great Barrier Reef. Environmental variables (i.e., several water quality and sediment parameters) and the composition of both benthic foraminiferal and hard-coral assemblages differed significantly between four regions (Whitsunday, Burdekin, Fitzroy, and the Wet Tropics). Grain size and organic carbon and nitrogen content of sediments, and a composite water column parameter (based on turbidity and concentrations of particulate matter) explained a significant amount of variation in the data (tested by redundancy analyses) in both assemblages. Heterotrophic species of foraminifera were dominant in sediments with high organic content and in localities with low light availability, whereas symbiont-bearing mixotrophic species were dominant elsewhere. A similar suite of parameters explained 89% of the variation in the FORAM index (a Caribbean coral reef health indicator) and 61% in foraminiferal species richness. Coral richness was not related to environmental setting. Coral assemblages varied in response to environmental variables, but were strongly shaped by acute disturbances (e.g., cyclones, Acanthaster planci outbreaks, and bleaching), thus different coral assemblages may be found at sites with the same environmental conditions. Disturbances also affect foraminiferal assemblages, but they appeared to recover more rapidly than corals. Foraminiferal assemblages are effective bioindicators of turbidity/light regimes and organic enrichment of sediments on coral reefs.

  16. Coral reef remote sensing applications

    OpenAIRE

    Kuchler, D.A.; Jupp, D.L.B.; Claasen, D.B.; Bour, William

    1986-01-01

    Great Barrier Reef work is the major example used to describe how remote sensing technology is being applied in coral reef studies. Such studies include reef geography, reef form, surface cover, vegetation, micro aspects and oceanography. New generation sensors optimized for oceanographic applications, means that coral reef and oceanic studies will adopt more precise and more extensive uses of remote sensing technology. (Résumé d'auteur)

  17. Remote sensing of sea surface temperatures during 2002 Barrier Reef coral bleaching

    Science.gov (United States)

    Liu, Gang; Strong, Alan E.; Skirving, William

    Early in 2002, satellites of the U.S. National Oceanic and Atmospheric Administration (NOAA) detected anomalously high sea surface temperatures (SST) developing in the western Coral Sea, midway along Australia's Great Barrier Reef (GBR). This was the beginning of what was to become the most significant GBR coral bleaching event on record [Wilkinson, 2002]. During this time, NOAA's National Environmental Satellite, Data, and Information Service (NESDIS) provided satellite data as part of ongoing collaborative work on coral reef health with the Australian Institute of Marine Science (AIMS) and the Great Barrier Reef Marine Park Authority (GBRMPA). These data proved invaluable to AIMS and GBRMPA as they monitored and assessed the development and evolution of SSTs throughout the austral summer, enabling them to keep stakeholders, government, and the general public informed and up to date.

  18. Environmental Records from Great Barrier Reef Corals: inshore versus offshore drivers.

    Directory of Open Access Journals (Sweden)

    Benjamin D Walther

    Full Text Available The biogenic structures of stationary organisms can be effective recorders of environmental fluctuations. These proxy records of environmental change are preserved as geochemical signals in the carbonate skeletons of scleractinian corals and are useful for reconstructions of temporal and spatial fluctuations in the physical and chemical environments of coral reef ecosystems, including The Great Barrier Reef (GBR. We compared multi-year monitoring of water temperature and dissolved elements with analyses of chemical proxies recorded in Porites coral skeletons to identify the divergent mechanisms driving environmental variation at inshore versus offshore reefs. At inshore reefs, water Ba/Ca increased with the onset of monsoonal rains each year, indicating a dominant control of flooding on inshore ambient chemistry. Inshore multi-decadal records of coral Ba/Ca were also highly periodic in response to flood-driven pulses of terrigenous material. In contrast, an offshore reef at the edge of the continental shelf was subject to annual upwelling of waters that were presumed to be richer in Ba during summer months. Regular pulses of deep cold water were delivered to the reef as indicated by in situ temperature loggers and coral Ba/Ca. Our results indicate that although much of the GBR is subject to periodic environmental fluctuations, the mechanisms driving variation depend on proximity to the coast. Inshore reefs are primarily influenced by variable freshwater delivery and terrigenous erosion of catchments, while offshore reefs are dominated by seasonal and inter-annual variations in oceanographic conditions that influence the propensity for upwelling. The careful choice of sites can help distinguish between the various factors that promote Ba uptake in corals and therefore increase the utility of corals as monitors of spatial and temporal variation in environmental conditions.

  19. Spatial variation in background mortality among dominant coral taxa on Australia's Great Barrier Reef.

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    Pisapia, Chiara; Pratchett, Morgan S

    2014-01-01

    Even in the absence of major disturbances (e.g., cyclones, bleaching), corals are consistently subject to high levels of background mortality, which undermines individual fitness and resilience of coral colonies. Partial mortality may impact coral response to climate change by reducing colony ability to recover between major acute stressors. This study quantified proportion of injured versus uninjured colonies (the prevalence of injuries) and instantaneous measures of areal extent of injuries across individual colonies (the severity of injuries), in four common coral species along the Great Barrier Reef in Australia: massive Porites, encrusting Montipora, Acropora hyacinthus and Pocillopora damicornis. A total of 2,276 adult colonies were surveyed three latitudinal sectors, nine reefs and 27 sites along 1000 km2 on the Great Barrier Reef. The prevalence of injuries was very high, especially for Porites spp (91%) and Montipora encrusting (85%) and varied significantly, but most lay at small spatial scales (e.g., among colonies positioned coral capacity to cope with increasing acute disturbances, such as climate-induced coral bleaching. These data are important for understanding coral responses to increasing stressors, and in particular for predicting their capacity to recover between subsequent disturbances. PMID:24959921

  20. Surviving Coral Bleaching Events: Porites Growth Anomalies on the Great Barrier Reef

    OpenAIRE

    Cantin, Neal E.; Lough, Janice M.

    2014-01-01

    Mass coral bleaching affected large parts of the Great Barrier Reef (GBR) in 1998 and 2002. In this study, we assessed if signatures of these major thermal stress events were recorded in the growth characteristics of massive Porites colonies. In 2005 a suite of short (

  1. Surface alkaline phosphatase activities of macroalgae on coral reefs of the central Great Barrier Reef, Australia

    Science.gov (United States)

    Schaffelke, B.

    2001-05-01

    Inshore reefs of the Great Barrier Reef (GBR) are subject to episodic nutrient supply, mainly by flood events, whereas midshelf reefs have a more consistent low nutrient availability. Alkaline phosphatase activity (APA) enables macroalgae to increase their phosphorus (P) supply by using organic P. APA was high (~4.0 to 15.5 µmol PO4 3- g DW-1 h-1) in species colonising predominantly inshore reefs and low (human activity, which currently is a global problem.

  2. Climate change disables coral bleaching protection on the Great Barrier Reef.

    Science.gov (United States)

    Ainsworth, Tracy D; Heron, Scott F; Ortiz, Juan Carlos; Mumby, Peter J; Grech, Alana; Ogawa, Daisie; Eakin, C Mark; Leggat, William

    2016-04-15

    Coral bleaching events threaten the sustainability of the Great Barrier Reef (GBR). Here we show that bleaching events of the past three decades have been mitigated by induced thermal tolerance of reef-building corals, and this protective mechanism is likely to be lost under near-future climate change scenarios. We show that 75% of past thermal stress events have been characterized by a temperature trajectory that subjects corals to a protective, sub-bleaching stress, before reaching temperatures that cause bleaching. Such conditions confer thermal tolerance, decreasing coral cell mortality and symbiont loss during bleaching by over 50%. We find that near-future increases in local temperature of as little as 0.5°C result in this protective mechanism being lost, which may increase the rate of degradation of the GBR. PMID:27081069

  3. SPATIAL HETEROGENEITY OF PHOTOSYNTHETIC ACTIVITY WITHIN DISEASED CORALS FROM THE GREAT BARRIER REEF

    DEFF Research Database (Denmark)

    Roff, George; Ulstrup, Karin Elizabeth; Fine, Maoz;

    2008-01-01

    Morphological diagnosis and descriptions of seven disease-like syndromes affecting scleractinian corals were characterized from the southern Great Barrier Reef (GBR). Chl a fluorescence of PSII was measured using an Imaging-PAM (pulse amplitude modulated) fluorometer, enabling visualization of the...... associated with white patch syndrome appeared to impact primarily on the symbiotic dinoflagellates, as evidenced by declines in minimum fluorescence (F0) and maximum quantum yield (Fv/Fm), with no indication of degeneration in the host tissues. Our results suggest that for the majority of coral syndromes...... from the GBR, pathogenesis occurs in the host tissue, while the impact on the zooxanthellae populations residing in affected corals is minimal....

  4. The 27–year decline of coral cover on the Great Barrier Reef and its causes

    OpenAIRE

    De’ath, Glenn; Fabricius, Katharina E.; Sweatman, Hugh; Puotinen, Marji

    2012-01-01

    The world’s coral reefs are being degraded, and the need to reduce local pressures to offset the effects of increasing global pressures is now widely recognized. This study investigates the spatial and temporal dynamics of coral cover, identifies the main drivers of coral mortality, and quantifies the rates of potential recovery of the Great Barrier Reef. Based on the world’s most extensive time series data on reef condition (2,258 surveys of 214 reefs over 1985–2012), we show a major decline...

  5. Spatial variation in background mortality among dominant coral taxa on Australia's Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Chiara Pisapia

    Full Text Available Even in the absence of major disturbances (e.g., cyclones, bleaching, corals are consistently subject to high levels of background mortality, which undermines individual fitness and resilience of coral colonies. Partial mortality may impact coral response to climate change by reducing colony ability to recover between major acute stressors. This study quantified proportion of injured versus uninjured colonies (the prevalence of injuries and instantaneous measures of areal extent of injuries across individual colonies (the severity of injuries, in four common coral species along the Great Barrier Reef in Australia: massive Porites, encrusting Montipora, Acropora hyacinthus and Pocillopora damicornis. A total of 2,276 adult colonies were surveyed three latitudinal sectors, nine reefs and 27 sites along 1000 km2 on the Great Barrier Reef. The prevalence of injuries was very high, especially for Porites spp (91% and Montipora encrusting (85% and varied significantly, but most lay at small spatial scales (e.g., among colonies positioned <10-m apart. Similarly, severity of background partial mortality was surprisingly high (between 5% and 21% but varied greatly among colonies within the same site and habitat. This study suggests that intraspecific variation in partial mortality between adjacent colonies may be more important than variation between colonies in different latitudinal sectors or reefs. Differences in the prevalence and severity of background partial mortality have significant ramifications for coral capacity to cope with increasing acute disturbances, such as climate-induced coral bleaching. These data are important for understanding coral responses to increasing stressors, and in particular for predicting their capacity to recover between subsequent disturbances.

  6. Biogeochemical responses following coral mass spawning on the Great Barrier Reef: pelagic-benthic coupling

    Science.gov (United States)

    Wild, C.; Jantzen, C.; Struck, U.; Hoegh-Guldberg, O.; Huettel, M.

    2008-03-01

    This study quantified how the pulse of organic matter from the release of coral gametes triggered a chain of pelagic and benthic processes during an annual mass spawning event on the Australian Great Barrier Reef. Particulate organic matter (POM) concentrations in reef waters increased by threefold to 11-fold the day after spawning and resulted in a stimulation of pelagic oxygen consumption rates that lasted for at least 1 week. Water column microbial communities degraded the organic carbon of gametes of the broadcast-spawning coral Acropora millepora at a rate of >15% h-1, which is about three times faster than the degradation rate measured for larvae of the brooding coral Stylophora pistillata. Stable isotope signatures of POM in the water column reflected the fast transfer of organic matter from coral gametes into higher levels of the food chain, and the amount of POM reaching the seafloor immediately increased after coral spawning and then tailed-off in the next 2 weeks. Short-lasting phytoplankton blooms developed within a few days after the spawning event, indicating a prompt recycling of nutrients released through the degradation of spawning products. These data show the profound effects of coral mass spawning on the reef community and demonstrate the tight recycling of nutrients in this oligotrophic ecosystem.

  7. Coral records of reef-water pH across the central Great Barrier Reef, Australia: assessing the influence of river runoff on inshore reefs

    Directory of Open Access Journals (Sweden)

    J. P. D'Olivo

    2014-07-01

    Full Text Available The boron isotopic (δ11Bcarb compositions of long-lived Porites coral are used to reconstruct reef-water pH across the central Great Barrier Reef (GBR and assess the impact of river runoff on inshore reefs. For the period from 1940 to 2009, corals from both inner as well as mid-shelf sites exhibit the same overall decrease in δ11Bcarb of 0.086 ± 0.033‰ per decade, equivalent to a~decline in seawater pH (pHsw of ~ 0.017 ± 0.007 pH units per decade. This decline is consistent with the long-term effects of ocean acidification based on estimates of CO2 uptake by surface waters due to rising atmospheric levels. We also find that compared to the mid-shelf corals, the δ11Bcarb compositions for inner shelf corals subject to river discharge events, have higher and more variable values and hence higher inferred pHsw values. These higher δ11Bcarb values for inner-shelf corals are particularly evident during wet years, despite river waters having lower pH. The main effect of river discharge on reef-water carbonate chemistry thus appears to be from higher nutrients driving increased phytoplankton productivity, resulting in the drawdown of pCO2 and increase in pHsw. Increased primary production therefore has the potential to counter the more transient effects of low pH river water (pHrw discharged into near-shore environments. Importantly however, inshore reefs also show a consistent pattern of sharply declining coral growth that coincides with periods of high river discharge. This occurs despite these reefs having higher pHsw values and hence higher seawater aragonite saturation states, demonstrating the over-riding importance of local reef-water quality on coral reef health.

  8. Summer hot snaps and winter conditions: modelling white syndrome outbreaks on Great Barrier Reef corals.

    Directory of Open Access Journals (Sweden)

    Scott F Heron

    Full Text Available Coral reefs are under increasing pressure in a changing climate, one such threat being more frequent and destructive outbreaks of coral diseases. Thermal stress from rising temperatures has been implicated as a causal factor in disease outbreaks observed on the Great Barrier Reef, Australia, and elsewhere in the world. Here, we examine seasonal effects of satellite-derived temperature on the abundance of coral diseases known as white syndromes on the Great Barrier Reef, considering both warm stress during summer and deviations from mean temperatures during the preceding winter. We found a high correlation (r(2 = 0.953 between summer warm thermal anomalies (Hot Snap and disease abundance during outbreak events. Inclusion of thermal conditions during the preceding winter revealed that a significant reduction in disease outbreaks occurred following especially cold winters (Cold Snap, potentially related to a reduction in pathogen loading. Furthermore, mild winters (i.e., neither excessively cool nor warm frequently preceded disease outbreaks. In contrast, disease outbreaks did not typically occur following warm winters, potentially because of increased disease resistance of the coral host. Understanding the balance between the effects of warm and cold winters on disease outbreak will be important in a warming climate. Combining the influence of winter and summer thermal effects resulted in an algorithm that yields both a Seasonal Outlook of disease risk at the conclusion of winter and near real-time monitoring of Outbreak Risk during summer. This satellite-derived system can provide coral reef managers with an assessment of risk three-to-six months in advance of the summer season that can then be refined using near-real-time summer observations. This system can enhance the capacity of managers to prepare for and respond to possible disease outbreaks and focus research efforts to increase understanding of environmental impacts on coral disease in

  9. Carbon budget of coral reef systems: an overview of observations in fringing reefs, barrier reefs and atolls in the Indo-Pacific regions

    International Nuclear Information System (INIS)

    The seawater CO2 system and carbon budget were examined in coral reefs of wide variety with respect to topographic types and oceanographic settings in the Indo-Pacific oceans. A system-level net organic-to-inorganic carbon production ratio (ROI) is a master parameter for controlling the carbon cycle in coral reef systems, including their sink/source behavior for atmospheric CO2. A reef system with ROI less than approximately 0.6 has a potential for releasing CO2. The production ratio, however, is not easy to estimate on a particular reef. Instead, observations planned to detect the offshore-lagoon difference in partial pressure of CO2 (pCO2) and a graphic approach based on a total alkalinity-dissolved inorganic carbon diagram can reveal system-level performance of the carbon cycle in coral reefs. Surface pCO2 values in the lagoons of atolls and barrier reefs were consistently higher than those in their offshore waters, showing differences between 6 and 46 atm, together with a depletion in total alkalinity up to 100 mol/kg, indicating predominant carbonate production relative to net organic carbon production. Reef topography, especially residence time of lagoon water, has a secondary effect on the magnitude of the offshore-lagoon pCO2 difference. Terrestrial influence was recognized in coastal reefs, including the GBR lagoon and a fringing reef of the Ryukyu Islands. High carbon input appears to enhance CO2 efflux to the atmosphere because of their high dissolved C:P ratios. Coral reefs, in general, act as an alkalinity sink and a potentially CO2-releasing site due to carbonate precipitation and land-derived carbon

  10. What's Behind the Spread of White Syndrome in Great Barrier Reef Corals?

    OpenAIRE

    John F. Bruno; Elizabeth R Selig; Casey, Kenneth S.; Cathie A Page; Willis, Bette L.; C Drew Harvell; Hugh Sweatman; Amy M Melendy

    2007-01-01

    Author Summary Coral reefs have been decimated over the last several decades. The global decline of reef-building corals is of particular concern. Infectious diseases are thought to be key to this mass coral mortality, and many reef ecologists suspect that anomalously high ocean temperatures contribute to the increased incidence and severity of disease outbreaks. This hypothesis is supported by local observations—for example, that some coral diseases become more prevalent in the summertime—bu...

  11. The ecology of 'Acroporid white syndrome', a coral disease from the southern Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    George Roff

    Full Text Available Outbreaks of coral disease have increased worldwide over the last few decades. Despite this, remarkably little is known about the ecology of disease in the Indo-Pacific Region. Here we report the spatiotemporal dynamics of a coral disease termed 'Acroporid white syndrome' observed to affect tabular corals of the genus Acropora on the southern Great Barrier Reef. The syndrome is characterised by rapid tissue loss initiating in the basal margins of colonies, and manifests as a distinct lesion boundary between apparently healthy tissue and exposed white skeleton. Surveys of eight sites around Heron Reef in 2004 revealed a mean prevalence of 8.1±0.9%, affecting the three common species (Acropora cytherea, A. hyacinthus, A. clathrata and nine other tabular Acropora spp. While all sizes of colonies were affected, white syndrome disproportionately affected larger colonies of tabular Acroporids (>80 cm. The prevalence of white syndrome was strongly related to the abundance of tabular Acroporids within transects, yet the incidence of the syndrome appears unaffected by proximity to other colonies, suggesting that while white syndrome is density dependant, it does not exhibit a strongly aggregated spatial pattern consistent with previous coral disease outbreaks. Acroporid white syndrome was not transmitted by either direct contact in the field or by mucus in aquaria experiments. Monitoring of affected colonies revealed highly variable rates of tissue loss ranging from 0 to 1146 cm(-2 week(-1, amongst the highest documented for a coral disease. Contrary to previous links between temperature and coral disease, rates of tissue loss in affected colonies increased threefold during the winter months. Given the lack of spatial pattern and non-infectious nature of Acroporid white syndrome, further studies are needed to determine causal factors and longer-term implications of disease outbreaks on the Great Barrier Reef.

  12. Assessing the value of Earth Observation for managing coral reefs: an example from the Great Barrier Reef.

    Science.gov (United States)

    Bouma, Jetske A; Kuik, Onno; Dekker, Arnold G

    2011-10-01

    The Integrated Global Observing Strategy (IGOS, 2003) argues that further investments in Earth Observation information are required to improve coral reef protection worldwide. The IGOS Strategy does not specify what levels of investments are needed nor does it quantify the benefits associated with better-protected reefs. Evaluating costs and benefits is important for determining optimal investment levels and for convincing policy-makers that investments are required indeed. Few studies have quantitatively assessed the economic benefits of Earth Observation information or evaluated the economic value of information for environmental management. This paper uses an expert elicitation approach based on Bayesian Decision Theory to estimate the possible contribution of global Earth Observation to the management of the Great Barrier Reef. The Great Barrier Reef including its lagoon is a World Heritage Area affected by anthropogenic changes in land-use as well as climate change resulting in increased flows of sediments, nutrients and carbon to the GBR lagoon. Since European settlement, nutrient and sediment loads having increased 5-10 times and the change in water quality is causing damages to the reef. Earth Observation information from ocean and coastal color satellite sensors can provide spatially and temporally dense information on sediment flows. We hypothesize that Earth Observation improves decision-making by enabling better-targeted run-off reduction measures and we assess the benefits (cost savings) of this improved targeting by optimizing run-off reductions under different states of the world. The analysis suggests that the benefits of Earth Observation can indeed be substantial, depending on the perceived accuracy of the information and on the prior beliefs of decision-makers. The results indicate that increasing informational accuracy is the most effective way for developers of Earth Observation information to increase the added value of Earth Observation for

  13. Metagenomic analysis of the coral holobiont during a natural bleaching event on the Great Barrier Reef.

    Science.gov (United States)

    Littman, Raechel; Willis, Bette L; Bourne, David G

    2011-12-01

    Understanding the effects of elevated seawater temperatures on each member of the coral holobiont (the complex comprised of coral polyps and associated symbiotic microorganisms, including Bacteria, viruses, Fungi, Archaea and endolithic algae) is becoming increasingly important as evidence accumulates that microbial members contribute to overall coral health, particularly during thermal stress. Here we use a metagenomic approach to identify metabolic and taxonomic shifts in microbial communities associated with the hard coral Acropora millepora throughout a natural thermal bleaching event at Magnetic Island (Great Barrier Reef). A direct comparison of metagenomic data sets from healthy versus bleached corals indicated major shifts in microbial associates during heat stress, including Bacteria, Archaea, viruses, Fungi and micro-algae. Overall, metabolism of the microbial community shifted from autotrophy to heterotrophy, including increases in genes associated with the metabolism of fatty acids, proteins, simple carbohydrates, phosphorus and sulfur. In addition, the proportion of virulence genes was higher in the bleached library, indicating an increase in microorganisms capable of pathogenesis following bleaching. These results demonstrate that thermal stress results in shifts in coral-associated microbial communities that may lead to deteriorating coral health. PMID:23761353

  14. Surviving coral bleaching events: porites growth anomalies on the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Neal E Cantin

    Full Text Available Mass coral bleaching affected large parts of the Great Barrier Reef (GBR in 1998 and 2002. In this study, we assessed if signatures of these major thermal stress events were recorded in the growth characteristics of massive Porites colonies. In 2005 a suite of short (<50 cm cores were collected from apparently healthy, surviving Porites colonies, from reefs in the central GBR (18-19°S that have documented observations of widespread bleaching. Sites included inshore (Nelly Bay, Pandora Reef, annually affected by freshwater flood events, midshelf (Rib Reef, only occasionally affected by freshwater floods and offshore (Myrmidon Reef locations primarily exposed to open ocean conditions. Annual growth characteristics (extension, density and calcification were measured in 144 cores from 79 coral colonies and analysed over the common 24-year period, 1980-2003. Visual examination of the annual density bands revealed growth hiatuses associated with the bleaching years in the form of abrupt decreases in annual linear extension rates, high density stress bands and partial mortality. The 1998 mass-bleaching event reduced Porites calcification by 13 and 18% on the two inshore locations for 4 years, followed by recovery to baseline calcification rates in 2002. Evidence of partial mortality was apparent in 10% of the offshore colonies in 2002; however no significant effects of the bleaching events were evident in the calcification rates at the mid shelf and offshore sites. These results highlight the spatial variation of mass bleaching events and that all reef locations within the GBR were not equally stressed by the 1998 and 2002 mass bleaching events, as some models tend to suggest, which enabled recovery of calcification on the GBR within 4 years. The dynamics in annual calcification rates and recovery displayed here should be used to improve model outputs that project how coral calcification will respond to ongoing warming of the tropical oceans.

  15. An assessment of an environmental gradient using coral geochemical records, Whitsunday Islands, Great Barrier Reef, Australia

    International Nuclear Information System (INIS)

    Coral cores were collected along an environmental and water quality gradient through the Whitsunday Island group, Great Barrier Reef (Australia), for trace element and stable isotope analysis. The primary aim of the study was to examine if this gradient could be detected in coral records and, if so, whether the gradient has changed over time with changing land use in the adjacent river catchments. Y/Ca was the trace element ratio which varied spatially across the gradient, with concentrations progressively decreasing away from the river mouths. The Ba/Ca and Y/Ca ratios were the only indicators of change in the gradient through time, increasing shortly after European settlement. The Mn/Ca ratio responded to local disturbance related to the construction of tourism infrastructure. Nitrogen isotope ratios showed no apparent trend over time. This study highlights the importance of site selection when using coral records to record regional environmental signals.

  16. The Ecology of ‘Acroporid White Syndrome', a Coral Disease from the Southern Great Barrier Reef

    OpenAIRE

    George Roff; Kvennefors, E. Charlotte E.; Maoz Fine; Juan Ortiz; Davy, Joanne E.; Ove Hoegh-Guldberg

    2011-01-01

    Outbreaks of coral disease have increased worldwide over the last few decades. Despite this, remarkably little is known about the ecology of disease in the Indo-Pacific Region. Here we report the spatiotemporal dynamics of a coral disease termed 'Acroporid white syndrome' observed to affect tabular corals of the genus Acropora on the southern Great Barrier Reef. The syndrome is characterised by rapid tissue loss initiating in the basal margins of colonies, and manifests as a distinct lesion b...

  17. Wave transformations across a Caribbean fringing-barrier Coral Reef

    Science.gov (United States)

    Lugo-Fernández, Alexis; Roberts, Harry H.; Suhayda, Joseph N.

    1998-08-01

    Wave measurements during three experiments at Tague Reef, St. Croix (U.S.V.I.) in April 1987 showed a net energy decrease across the reef profile of 65-71% between the forereef and crest, wave propagation to the backreef increased energy reduction to 78-88%. Tidally induced water depth changes (range of 0.3 m) increased wave energy dissipation by 15% between forereef and crest and 20% between forereef and backreef. Significant wave heights throughout the experiment were low (reef averaged 0.46 and modulated by the tide (0.32 at low tide vs 0.62 at high tide). The spectral time-delay model applied to analyzed wave transformations across the reef produced attenuation coefficients that averaged 0.62 between 0.05 and 0.1 cps (20-10 s) and afterwards oscillate between 0.22 and 0.35. For waves between the forereef and backreef, the attenuation coefficients from the time-delay model decay exponentially between 0.05 and 0.1 cps, afterwards they oscillate between 0.13 and 0.2. The steady wave-energy model with bottom friction, essentially form drag, and wave breaking dissipation yield wave heights modulated by the tides and errors of 20% at the backreef. The model revealed that while frictional and wave-breaking dissipation are equally important, frictional dissipation is greater.

  18. Coral community responses to declining water quality: Whitsunday Islands, Great Barrier Reef, Australia

    Science.gov (United States)

    Thompson, Angus; Schroeder, Thomas; Brando, Vittorio E.; Schaffelke, Britta

    2014-12-01

    A five-year period (2002-2006) of below-median rainfall followed by a six-year period (2007-2012) of above-median rainfall and seasonal flooding allowed a natural experiment into the effects of runoff on the water quality and subsequent coral community responses in the Whitsunday Islands, Great Barrier Reef (Australia). Satellite-derived water quality estimates of total suspended solids (TSS) and chlorophyll- a (Chl) concentration showed marked seasonal variability that was exaggerated during years with high river discharge. During above-median rainfall years, Chl was aseasonally high for a period of 3 months during the wet season (February-April), while TSS was elevated for four months, extending into the dry season (March-June). Coinciding with these extremes in water quality was a reduction in the abundance and shift in the community composition, of juvenile corals. The incidence of coral disease was at a maximum during the transition from years of below-median to years of above-median river discharge. In contrast to juvenile corals, the cover of larger corals remained stable, although the composition of communities varied along environmental gradients. In combination, these results suggest opportunistic recruitment of corals during periods of relatively low environmental stress with selection for more tolerant species occurring during periods of environmental extremes.

  19. Diel coral reef acidification driven by porewater advection in permeable sands, Heron Island, Great Barrier Reef

    DEFF Research Database (Denmark)

    Santos, Isaac R.; Glud, Ronnie N.; Maher, Damien;

    2011-01-01

    Little is known about how biogeochemical processes in permeable sediments affect the pH of coastal waters. We demonstrate that seawater recirculation in permeable sands can play a major role in proton (H+) cycling in a coral reef lagoon. The diel pH range (up to 0.75 units) in the Heron Island...... lagoon was the broadest ever reported for reef waters, and the night‐time pH (7.69) was comparable to worst‐case scenario predictions for seawater pH in 2100. The net contribution of coarse carbonate sands to the whole system H+ fluxes was only 9% during the day, but approached 100% at night when small...... scale (i.e., flow and topography‐induced pressure gradients) and large scale (i.e., tidal pumping as traced by radon) seawater recirculation processes were synergistic. Reef lagoon sands were a net sink for H+, and the sink strength was a function of porewater flushing rate. Our observations suggest...

  20. Dynamics of seawater carbonate chemistry, production, and calcification of a coral reef flat, central Great Barrier Reef

    Directory of Open Access Journals (Sweden)

    R. Albright

    2013-10-01

    Full Text Available Ocean acidification is projected to shift coral reefs from a state of net accretion to one of net dissolution this century. Presently, our ability to predict global-scale changes to coral reef calcification is limited by insufficient data relating seawater carbonate chemistry parameters to in situ rates of reef calcification. Here, we investigate diel and seasonal trends in carbonate chemistry of the Davies Reef flat in the central Great Barrier Reef and relate these trends to benthic carbon fluxes by quantifying net ecosystem calcification (nec and net community production (ncp. Results show that seawater carbonate chemistry of the Davies Reef flat is highly variable over both diel and seasonal cycles. pH (total scale ranged from 7.92 to 8.17, pCO2 ranged from 272 to 542 μatm, and aragonite saturation state (Ωarag ranged from 2.9 to 4.1. Diel cycles in carbonate chemistry were primarily driven by ncp, and warming explained 35% and 47% of the seasonal shifts in pCO2 and pH, respectively. Daytime ncp averaged 37 ± 19 mmol C m−2 h−1 in summer and 33 ± 13 mmol C m−2 h−1 in winter; nighttime ncp averaged −30 ± 25 and −7 ± 6 mmol C m−2 h−1 in summer and winter, respectively. Daytime nec averaged 11 ± 4 mmol CaCO3 m−2 h−1 in summer and 8 ± 3 mmol CaCO3 m−2 h−1 in winter, whereas nighttime nec averaged 2 ± 4 mmol and −1 ± 3 mmol CaCO3 m−2 h−1 in summer and winter, respectively. Net ecosystem calcification was highly sensitive to changes in Ωarag for both seasons, indicating that relatively small shifts in Ωarag may drive measurable shifts in calcification rates, and hence carbon budgets, of coral reefs throughout the year.

  1. Coral-macroalgal phase shifts or reef resilience: links with diversity and functional roles of herbivorous fishes on the Great Barrier Reef

    Science.gov (United States)

    Cheal, A. J.; MacNeil, M. Aaron; Cripps, E.; Emslie, M. J.; Jonker, M.; Schaffelke, B.; Sweatman, H.

    2010-12-01

    Changes from coral to macroalgal dominance following disturbances to corals symbolize the global degradation of coral reefs. The development of effective conservation measures depends on understanding the causes of such phase shifts. The prevailing view that coral-macroalgal phase shifts commonly occur due to insufficient grazing by fishes is based on correlation with overfishing and inferences from models and small-scale experiments rather than on long-term quantitative field studies of fish communities at affected and resilient sites. Consequently, the specific characteristics of herbivorous fish communities that most promote reef resilience under natural conditions are not known, though this information is critical for identifying vulnerable ecosystems. In this study, 11 years of field surveys recorded the development of the most persistent coral-macroalgal phase shift (>7 years) yet observed on Australia’s Great Barrier Reef (GBR). This shift followed extensive coral mortality caused by thermal stress (coral bleaching) and damaging storms. Comparisons with two similar reefs that suffered similar disturbances but recovered relatively rapidly demonstrated that the phase shift occurred despite high abundances of one herbivore functional group (scraping/excavating parrotfishes: Labridae). However, the shift was strongly associated with low fish herbivore diversity and low abundances of algal browsers (predominantly Siganidae) and grazers/detritivores (Acanthuridae), suggesting that one or more of these factors underpin reef resilience and so deserve particular protection. Herbivorous fishes are not harvested on the GBR, and the phase shift was not enhanced by unusually high nutrient levels. This shows that unexploited populations of herbivorous fishes cannot ensure reef resilience even under benign conditions and suggests that reefs could lose resilience under relatively low fishing pressure. Predictions of more severe and widespread coral mortality due to global

  2. Coral-mucus-associated Vibrio integrons in the Great Barrier Reef: genomic hotspots for environmental adaptation

    OpenAIRE

    Koenig, Jeremy E.; Bourne, David G; Curtis, Bruce; Dlutek, Marlena; Stokes, H. W.; Doolittle, W Ford; Boucher, Yan

    2011-01-01

    Integron cassette arrays in a dozen cultivars of the most prevalent group of Vibrio isolates obtained from mucus expelled by a scleractinian coral (Pocillopora damicornis) colony living on the Great Barrier Reef were sequenced and compared. Although all cultivars showed >99% identity across recA, pyrH and rpoB genes, no two had more than 10% of their integron-associated gene cassettes in common, and some individuals shared cassettes exclusively with distantly-related members of the genus. Of ...

  3. Assessing loss of coral cover on Australia's Great Barrier Reef over two decades, with implications for longer-term trends

    Science.gov (United States)

    Sweatman, H.; Delean, S.; Syms, C.

    2011-06-01

    While coral reefs in many parts of the world are in decline as a direct consequence of human pressures, Australia's Great Barrier Reef (GBR) is unusual in that direct human pressures are low and the entire system of ~2,900 reefs has been managed as a marine park since the 1980s. In spite of these advantages, standard annual surveys of a large number of reefs showed that from 1986 to 2004, average live coral cover across the GBR declined from 28 to 22%. This overall decline was mainly due to large losses in six (21%) of 29 subregions. Declines in live coral cover on reefs in two inshore subregions coincided with thermal bleaching in 1998, while declines in four mid-self subregions were due to outbreaks of predatory starfish. Otherwise, living coral cover increased in one subregion (3%) and 22 subregions (76%) showed no substantial change. Reefs in the great majority of subregions showed cycles of decline and recovery over the survey period, but with little synchrony among subregions. Two previous studies examined long-term changes in live coral cover on GBR reefs using meta-analyses including historical data from before the mid-1980s. Both found greater rates of loss of coral and recorded a marked decrease in living coral cover on the GBR in 1986, coinciding exactly with the start of large-scale monitoring. We argue that much of the apparent long-term decrease results from combining data from selective, sparse, small-scale studies before 1986 with data from both small-scale studies and large-scale monitoring surveys after that date. The GBR has clearly been changed by human activities and live coral cover has declined overall, but losses of coral in the past 40-50 years have probably been overestimated.

  4. Dynamics of seawater carbonate chemistry, production, and calcification of a coral reef flat, Central Great Barrier Reef

    Directory of Open Access Journals (Sweden)

    R. Albright

    2013-05-01

    Full Text Available Ocean acidification is projected to shift coral reefs from a state of net accretion to one of net dissolution this century. Presently, our ability to predict global-scale changes to coral reef calcification is limited by insufficient data relating seawater carbonate chemistry parameters to in situ rates of reef calcification. Here, we investigate natural trends in carbonate chemistry of the Davies Reef flat in the central Great Barrier Reef on diel and seasonal timescales and relate these trends to benthic carbon fluxes by quantifying net ecosystem calcification (nec and net community production (ncp. Results show that seawater carbonate chemistry of the Davies Reef flat is highly variable over both diel and seasonal timescales. pH (total scale ranged from 7.92 to 8.17, pCO2 ranged from 272 to 542 μatm, and aragonite saturation state (Ωarag ranged from 2.9 to 4.1. Diel cycles in carbonate chemistry were primarily driven by ncp, and warming explained 35% and 47% of the seasonal shifts in pCO2 and pH, respectively. Daytime ncp averaged 36 ± 19 mmol C m−2 h−1 in summer and 33 ± 13 mmol C m−2 h−1 in winter; nighttime ncp averaged −22 ± 20 and −7 ± 6 mmol C m−2 h−1 in summer and winter, respectively. Daytime nec averaged 11 ± 4 mmol CaCO3 m−2 h−1 in summer and 8 ± 3 mmol CaCO3 m−2 h−1 in winter, whereas nighttime nec averaged 2 ± 4 mmol and −1 ± 3 mmol CaCO3 m−2 h−1 in summer and winter, respectively. Net ecosystem calcification was positively correlated with Ωarag for both seasons. Linear correlations of nec and Ωarag indicate that the Davies Reef flat may transition from a state of net calcification to net dissolution at Ωarag values of 3.4 in summer and 3.2 in winter. Diel trends in Ωarag indicate that the reef flat is currently below this calcification threshold 29.6% of the time in summer and 14.1% of the time in winter.

  5. Coral reefs and eutrophication

    International Nuclear Information System (INIS)

    Coral reefs are found in oligotrophic waters, which are poor in nutrients such as nitrogen, phosphate, and possibly iron. In spite of this, coral reefs exhibit high gross primary productivity rates. They thrive in oligotrophic conditions because of the symbiotic relationship between corals and dinoflagellate algae (zooxanthellae) embedded in the coral tissue. In their mutualistic symbiosis, the zooxanthellae contribute their photosynthetic capability as the basis for the metabolic energy of the whole association, and eventually of a great part of the entire reef ecosystem

  6. The Great Barrier Reef Ocean Observing System Mooring array: Monitoring the Western Boundary Currents of the Coral Sea and Impacts on the Great Barrier Reef

    Science.gov (United States)

    Steinberg, C. R.; McAllister, F.; Brinkman, B. W.; Pitcher, C.; Luetchford, J.; Rigby, P.

    2009-05-01

    Since 1987 Great Barrier Reef weather and water temperature observations have been transmitted in near real time using HF radio from pontoons or towers on coral reefs by AIMS. In contrast oceanographic measurements have however been restricted to loggers serviced at quarterly to half yearly downloads. The Great Barrier Reef Ocean Observing System (GBROOS) is a regional node of the Integrated Marine Observing System (IMOS). IMOS is an Australian Government initiative established under the National Collaborative Research Infrastructure Strategy and has been supported by Queensland Government since 2006. GBROOS comprises real time observations from weather stations, oceanographic moorings, underway ship observations, ocean surface radar, satellite image reception and reef based sensor networks. This paper focuses on an array of in-line moorings that have been deployed along the outer Great Barrier Reef in order to monitor the Western Boundary currents of the Coral Sea. The Westward flowing Southern Equatorial Current bifurcates into the poleward flowing East Australian Current and the equatorward North Queensland Current. The 4 mooring pairs consist of a continental slope mooring, nominally in 200m of water and one on the outer continental shelf within the GBR matrix in depths of 30 to 70m. The array is designed to detect any changes in circulation, temperature response, mixed layer depth and ocean-shelf interactions. A review of likely impacts of climate change on the physical oceanography of the GBR is providing a basis upon which to explore what processes may be affected by climate change. Sample data and results from the initial year of observations will be presented.

  7. Coral reef ecosystem

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.

    -determined intervals, (l) involvement of end-users and NCOs, (m) prevention of poaching, and (n) crisis management. Options for management of reefs and their resources are several. With extractive uses, they can vary from restrictions on the type of resource exploited... Committee on Mangroves and Coral Reefs of the Ministry of Environment and Forests (MoEF) is responsible for developing strategies for conservation and management of coral reefs and financially supporting their implementation. Besides the support to regional...

  8. Biology of corals and coral reefs

    Digital Repository Service at National Institute of Oceanography (India)

    Rajkumar, R.; Parulekar, A.H.

    on the systematic position is presented. The general structure is depicted with illustrations. Physiology part is updated to current knowledge on reproduction, nutrition and excretion of corals. The coral reefs section begins with status of world reefs...

  9. Coral-mucus-associated Vibrio integrons in the Great Barrier Reef: genomic hotspots for environmental adaptation.

    Science.gov (United States)

    Koenig, Jeremy E; Bourne, David G; Curtis, Bruce; Dlutek, Marlena; Stokes, H W; Doolittle, W Ford; Boucher, Yan

    2011-06-01

    Integron cassette arrays in a dozen cultivars of the most prevalent group of Vibrio isolates obtained from mucus expelled by a scleractinian coral (Pocillopora damicornis) colony living on the Great Barrier Reef were sequenced and compared. Although all cultivars showed >99% identity across recA, pyrH and rpoB genes, no two had more than 10% of their integron-associated gene cassettes in common, and some individuals shared cassettes exclusively with distantly-related members of the genus. Of cassettes shared within the population, a number appear to have been transferred between Vibrio isolates, as assessed by phylogenetic analysis. Prominent among the mucus Vibrio cassettes with potentially inferable functions are acetyltransferases, some with close similarity to known antibiotic-resistance determinants. A subset of these potential resistance cassettes were shared exclusively between the mucus Vibrio cultivars, Vibrio coral pathogens and human pathogens, thus illustrating a direct link between these microbial niches through exchange of integron-associated gene cassettes. PMID:21270840

  10. Coral reefs: Turning back time

    Science.gov (United States)

    Lough, Janice M.

    2016-03-01

    An in situ experiment finds that reducing the acidity of the seawater surrounding a natural coral reef significantly increases reef calcification, suggesting that ocean acidification may already be slowing coral growth. See Letter p.362

  11. Effect of colony size and surrounding substrate on corals experiencing a mild bleaching event on Heron Island reef flat (southern Great Barrier Reef, Australia)

    Science.gov (United States)

    Ortiz, J. C.; Gomez-Cabrera, M. Del C.; Hoegh-Guldberg, O.

    2009-12-01

    In January-May 2006, Heron Island in the Great Barrier Reef experienced a mild bleaching event. The effect of colony size, morphology and surrounding substrate on the extent of bleaching was explored. In contrast with previous studies, colony size did not influence bleaching sensitivity, suggesting that there may be a threshold of light and temperature stress beyond which size plays a role. Also contrasting with previous studies, massive corals were more affected by bleaching than branching corals. Massive corals surrounded by sand were more affected than the ones surrounded by rubble or dead coral. It is hypothesized that light reflectance from sand increases stress levels experienced by the colonies. This effect is maximized in massive corals as opposed to branching corals that form dense thickets on Heron Island. These results emphasize the importance of the ecological dynamics of coral communities experiencing low, moderate and high levels of bleaching for the understanding of how coral communities may change under the stress of climate change.

  12. Environmental factors controlling the distribution of symbiodinium harboured by the coral Acropora millepora on the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Timothy F Cooper

    Full Text Available BACKGROUND: The Symbiodinium community associated with scleractinian corals is widely considered to be shaped by seawater temperature, as the coral's upper temperature tolerance is largely contingent on the Symbiodinium types harboured. Few studies have challenged this paradigm as knowledge of other environmental drivers on the distribution of Symbiodinium is limited. Here, we examine the influence of a range of environmental variables on the distribution of Symbiodinium associated with Acropora millepora collected from 47 coral reefs spanning 1,400 km on the Great Barrier Reef (GBR, Australia. METHODOLOGY/PRINCIPAL FINDINGS: The environmental data included Moderate Resolution Imaging Spectroradiometer (MODIS satellite data at 1 km spatial resolution from which a number of sea surface temperature (SST and water quality metrics were derived. In addition, the carbonate and mud composition of sediments were incorporated into the analysis along with in situ water quality samples for a subset of locations. Analyses were conducted at three spatio-temporal scales [GBR (regional-scale, Whitsunday Islands (local-scale and Keppel Islands/Trunk Reef (temporal] to examine the effects of scale on the distribution patterns. While SST metrics were important drivers of the distribution of Symbiodinium types at regional and temporal scales, our results demonstrate that spatial variability in water quality correlates significantly with Symbiodinium distribution at local scales. Background levels of Symbiodinium types were greatest at turbid inshore locations of the Whitsunday Islands where SST predictors were not as important. This was not the case at regional scales where combinations of mud and carbonate sediment content coupled with SST anomalies and mean summer SST explained 51.3% of the variation in dominant Symbiodinium communities. CONCLUSIONS/SIGNIFICANCE: Reef corals may respond to global-scale stressors such as climate change through changes in their

  13. A novel reef coral symbiosis

    Science.gov (United States)

    Pantos, O.; Bythell, J. C.

    2010-09-01

    Reef building corals form close associations with unicellular microalgae, fungi, bacteria and archaea, some of which are symbiotic and which together form the coral holobiont. Associations with multicellular eukaryotes such as polychaete worms, bivalves and sponges are not generally considered to be symbiotic as the host responds to their presence by forming physical barriers with an active growth edge in the exoskeleton isolating the invader and, at a subcellular level, activating innate immune responses such as melanin deposition. This study describes a novel symbiosis between a newly described hydrozoan ( Zanclea margaritae sp. nov.) and the reef building coral Acropora muricata (= A. formosa), with the hydrozoan hydrorhiza ramifying throughout the coral tissues with no evidence of isolation or activation of the immune systems of the host. The hydrorhiza lacks a perisarc, which is typical of symbiotic species of this and related genera, including species that associate with other cnidarians such as octocorals. The symbiosis was observed at all sites investigated from two distant locations on the Great Barrier Reef, Australia, and appears to be host species specific, being found only in A. muricata and in none of 30 other species investigated at these sites. Not all colonies of A. muricata host the hydrozoans and both the prevalence within the coral population (mean = 66%) and density of emergent hydrozoan hydranths on the surface of the coral (mean = 4.3 cm-2, but up to 52 cm-2) vary between sites. The form of the symbiosis in terms of the mutualism-parasitism continuum is not known, although the hydrozoan possesses large stenotele nematocysts, which may be important for defence from predators and protozoan pathogens. This finding expands the known A. muricata holobiont and the association must be taken into account in future when determining the corals’ abilities to defend against predators and withstand stress.

  14. Historical photographs revisited: A case study for dating and characterizing recent loss of coral cover on the inshore Great Barrier Reef

    Science.gov (United States)

    Clark, Tara R.; Leonard, Nicole D.; Zhao, Jian-Xin; Brodie, Jon; McCook, Laurence J.; Wachenfeld, David R.; Duc Nguyen, Ai; Markham, Hannah L.; Pandolfi, John M.

    2016-01-01

    Long-term data with high-precision chronology are essential to elucidate past ecological changes on coral reefs beyond the period of modern-day monitoring programs. In 2012 we revisited two inshore reefs within the central Great Barrier Reef, where a series of historical photographs document a loss of hard coral cover between c.1890-1994 AD. Here we use an integrated approach that includes high-precision U-Th dating specifically tailored for determining the age of extremely young corals to provide a robust, objective characterisation of ecological transition. The timing of mortality for most of the dead in situ corals sampled from the historical photograph locations was found to coincide with major flood events in 1990-1991 at Bramston Reef and 1970 and 2008 at Stone Island. Evidence of some recovery was found at Bramston Reef with living coral genera similar to what was described in c.1890 present in 2012. In contrast, very little sign of coral re-establishment was found at Stone Island suggesting delayed recovery. These results provide a valuable reference point for managers to continue monitoring the recovery (or lack thereof) of coral communities at these reefs.

  15. Reefscape proxies for the conservation of Caribbean coral reef biodiversity

    OpenAIRE

    JE Arias-González; E Núñez-Lara; FA Rodríguez-Zaragoza; Legendre, P.

    2011-01-01

    The explanatory value of four hypotheses for geographic variation in total species richness and species richness was evaluated per family in coral and fish communities in the North Sector of the Mesoamerican Barrier Reef System (NS-MBRS). The four hypotheses emphasize different reefscape attributes that are important for coral and fish: reef area (RA), live coral cover (LCC), habitat complexity (HC), and coral richness itself and for fish. For both coral and fish communities, we estimated the...

  16. Nitrification in reef corals

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.; David, J.J.

    : 1004-1008. SCHILLER, C., AND G. J. HERNDL. 1988. Nutritive status and mineralization capacity in interstitial waters of narrow branched hermatypic corals. [Abstract 364.1 Proc. 6th Int. Coral Reef Svmu. SIEB~RTH, J. McN.* 1975. Microbial seascapes....-U&v. Park. STRICKLAND, J. D. H., AND T. R. PARSONS. 1972. A practical handbook of seawater analysis, 2nd ed. Bull. Fish. Res. Bd. Can. 167. TRENCH, R. K. 1974. Nutritional potentials in Zoan- thus sociatus. Helgol. Wiss. Meeresunters. 26: 174- 216...

  17. Coral reef resilience through biodiversity

    Science.gov (United States)

    Rogers, Caroline S.

    2013-01-01

    Irrefutable evidence of coral reef degradation worldwide and increasing pressure from rising seawater temperatures and ocean acidification associated with climate change have led to a focus on reef resilience and a call to “manage” coral reefs for resilience. Ideally, global action to reduce emission of carbon dioxide and other greenhouse gases will be accompanied by local action. Effective management requires reduction of local stressors, identification of the characteristics of resilient reefs, and design of marine protected area networks that include potentially resilient reefs. Future research is needed on how stressors interact, on how climate change will affect corals, fish, and other reef organisms as well as overall biodiversity, and on basic ecological processes such as connectivity. Not all reef species and reefs will respond similarly to local and global stressors. Because reef-building corals and other organisms have some potential to adapt to environmental changes, coral reefs will likely persist in spite of the unprecedented combination of stressors currently affecting them. The biodiversity of coral reefs is the basis for their remarkable beauty and for the benefits they provide to society. The extraordinary complexity of these ecosystems makes it both more difficult to predict their future and more likely they will have a future.

  18. Human activities threaten coral reefs

    International Nuclear Information System (INIS)

    Research indicates that 58 per cent of the coral reefs of the world are threatened by human activities. Pollution and global heating represent some of the threats. Coral reefs just beneath the surface of the sea are very sensitive to temperature changes. Since 1979, mass death of coral reefs has been reported increasingly often. More than 1000 marine species live in the coral reefs, among these are one fourth of all marine species of fish. It is imperative that the coral reefs be preserved, as coastal communities all over the world depend on them as sources of food and as they are the raw materials for important medicines. The article discusses the threats to the coral reefs in general and does not single out any particular energy-related activity as the principal threat. For instance, the El-Nino phenomenon of the Pacific Ocean is probably involved in mass death of coral reefs and in the North Sea large parts of deep-water reefs have been crushed by heavy beam trawlers fishing for bottom fish

  19. Disease of coral and coral reef fishes

    Science.gov (United States)

    Panek, Frank

    2008-01-01

    The Department of the Interior protects sensitive habitats amounting to about 3,600,000 acres of coral reefs and other submerged lands. These reefs are important ecosystems in 13 National Wildlife Refuges, 10 National Parks and in certain territorial waters such as the Wake Atoll.

  20. Impact of Global Warming on Coral Reefs

    Directory of Open Access Journals (Sweden)

    Sirilak CHUMKIEW

    2011-06-01

    Full Text Available In this paper, we review coral reef responses to climate variability and discuss the possible mechanisms by which climate impacts the coral reef ecosystem. Effects of oceanographic variables such as sea temperature, turbulence, salinity, and nutrients on the coral reef are discussed in terms of their influence on coral growth, reproduction, mortality, acclimation and adaptation. Organisms tend to be limited to specific thermal ranges with experimental findings showing that sufficient oxygen supply by ventilation and circulation only occurs within these ranges. Indirect effects of climate change on the food web are also discussed. Further integrative studies are required to improve our knowledge of the processes linking coral reef responses to future climate change scenarios.Graphical abstract► Incidence of coral reef bleaching on a worldwide scale: location of bleaching reports during 1979 - 2010. Maps are from ReefBase, www.reefbase.org: 1, Arabian Gulf (United Arab Emirates, Qatar, Iran; 2, Red Sea; 3, east Africa; 4, southern Africa (Mozambique, South Africa; 5, Madagascar; 6, Mauritius, Reunion; 7, Seychelles; 8, Chagos; 9, Maldives; 10, Sri Lanka/southern India; 11, Andaman Sea (Andamans, Thailand, Malaysia; 12, South China Sea (Vietnam, Paracel Islands; 13, Philippines; 14, Indonesia; 15, western Australia; 16, Great Barrier Reef; 17, Ryukyu Islands; 18, Mariana Islands; 19, Palau; 20, Papua New Guinea, Vanuatu; 21, Fiji; 22, Samoa; 23, French Polynesia (including Moorea; 24, Hawaiian Islands; 25, Easter Island; 26, Galapagos Islands; 27, equatorial eastern Pacific (Costa Rica, Cocos Island, Panama´, Colombia, Ecuador; 28, subtropical eastern Pacific (Mexico; 29, Mesoamerican reef system (Mexico, Belize, Honduras, Nicaragua; 30, Greater Antilles (Cuba, Haiti, Dominican Republic, Puerto Rico, Virgin Islands; 31, Bahamas, Florida; 32, Bermuda; 33, Lesser Antilles; 34, Curaçao, Aruba, Bonaire, Los Roques; 35, Brazil.

  1. Wave transformation over coral reefs

    Science.gov (United States)

    Young, Ian R.

    1989-07-01

    Ocean wave attenuation on coral reefs is discussed using data obtained from a preliminary field experiment and from the Seasat altimeter. Marked attenuation of the waves is observed, the rate being consistent with existing theories of bottom friction and wave breaking decay. In addition, there is a significant broadening of the spectrum during propagation across reefs. Three-dimensional effects, such as refraction and defraction, can also lead to substantial wave height reduction for significant distances adjacent to coral reefs. As a result, a matrix of such reefs provides significantly more wave attenuation than may initially be expected.

  2. 40 CFR 230.44 - Coral reefs.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... by increasing the level of suspended particulates. Coral organisms are extremely sensitive to...

  3. Global microbialization of coral reefs.

    Science.gov (United States)

    Haas, Andreas F; Fairoz, Mohamed F M; Kelly, Linda W; Nelson, Craig E; Dinsdale, Elizabeth A; Edwards, Robert A; Giles, Steve; Hatay, Mark; Hisakawa, Nao; Knowles, Ben; Lim, Yan Wei; Maughan, Heather; Pantos, Olga; Roach, Ty N F; Sanchez, Savannah E; Silveira, Cynthia B; Sandin, Stuart; Smith, Jennifer E; Rohwer, Forest

    2016-01-01

    Microbialization refers to the observed shift in ecosystem trophic structure towards higher microbial biomass and energy use. On coral reefs, the proximal causes of microbialization are overfishing and eutrophication, both of which facilitate enhanced growth of fleshy algae, conferring a competitive advantage over calcifying corals and coralline algae. The proposed mechanism for this competitive advantage is the DDAM positive feedback loop (dissolved organic carbon (DOC), disease, algae, microorganism), where DOC released by ungrazed fleshy algae supports copiotrophic, potentially pathogenic bacterial communities, ultimately harming corals and maintaining algal competitive dominance. Using an unprecedented data set of >400 samples from 60 coral reef sites, we show that the central DDAM predictions are consistent across three ocean basins. Reef algal cover is positively correlated with lower concentrations of DOC and higher microbial abundances. On turf and fleshy macroalgal-rich reefs, higher relative abundances of copiotrophic microbial taxa were identified. These microbial communities shift their metabolic potential for carbohydrate degradation from the more energy efficient Embden-Meyerhof-Parnas pathway on coral-dominated reefs to the less efficient Entner-Doudoroff and pentose phosphate pathways on algal-dominated reefs. This 'yield-to-power' switch by microorganism directly threatens reefs via increased hypoxia and greater CO2 release from the microbial respiration of DOC. PMID:27572833

  4. Effects of High Dissolved Inorganic and Organic Carbon Availability on the Physiology of the Hard Coral Acropora millepora from the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Friedrich W Meyer

    Full Text Available Coral reefs are facing major global and local threats due to climate change-induced increases in dissolved inorganic carbon (DIC and because of land-derived increases in organic and inorganic nutrients. Recent research revealed that high availability of labile dissolved organic carbon (DOC negatively affects scleractinian corals. Studies on the interplay of these factors, however, are lacking, but urgently needed to understand coral reef functioning under present and near future conditions. This experimental study investigated the individual and combined effects of ambient and high DIC (pCO2 403 μatm/ pHTotal 8.2 and 996 μatm/pHTotal 7.8 and DOC (added as Glucose 0 and 294 μmol L-1, background DOC concentration of 83 μmol L-1 availability on the physiology (net and gross photosynthesis, respiration, dark and light calcification, and growth of the scleractinian coral Acropora millepora (Ehrenberg, 1834 from the Great Barrier Reef over a 16 day interval. High DIC availability did not affect photosynthesis, respiration and light calcification, but significantly reduced dark calcification and growth by 50 and 23%, respectively. High DOC availability reduced net and gross photosynthesis by 51% and 39%, respectively, but did not affect respiration. DOC addition did not influence calcification, but significantly increased growth by 42%. Combination of high DIC and high DOC availability did not affect photosynthesis, light calcification, respiration or growth, but significantly decreased dark calcification when compared to both controls and DIC treatments. On the ecosystem level, high DIC concentrations may lead to reduced accretion and growth of reefs dominated by Acropora that under elevated DOC concentrations will likely exhibit reduced primary production rates, ultimately leading to loss of hard substrate and reef erosion. It is therefore important to consider the potential impacts of elevated DOC and DIC simultaneously to assess real world

  5. Hypoxia in paradise: widespread hypoxia tolerance in coral reef fishes.

    OpenAIRE

    Nilsson, Göran E.; Ostlund-Nilsson, Sara

    2004-01-01

    Using respirometry, we examined the hypoxia tolerance of 31 teleost fish species (seven families) inhabiting coral reefs at a 2-5 m depth in the lagoon at Lizard Island (Great Barrier Reef, Australia). All fishes studied maintained their rate of oxygen consumption down to relatively severe hypoxia (20-30% air saturation). Indeed, most fishes appeared unaffected by hypoxia until the oxygen level fell below 10% of air saturation. This, hitherto unrecognized, hypoxia tolerance among coral reef f...

  6. Coral reef surveys in India

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    This paper briefly describes the history of coral reef surveys in India. All the surveys done so far have used simple techniques, but they have been quite effective in highlighting the damages to reefs in the short-term due to human interferences...

  7. Fisheries management: what chance on coral reefs?

    OpenAIRE

    Russ, G R

    1996-01-01

    Failures of fishery management to control fishing effort globally and how this affects the coral reef fisheries are discussed. The use of marine reserves in coral reef fisheries management is also emphasized.

  8. Status of coral reefs of India

    Digital Repository Service at National Institute of Oceanography (India)

    Muley, E.V.; Venkataraman, K.; Alfred, J.R.B.; Wafar, M.V.M.

    and economic significance of coral reefs and the threat perceptions, Government of India has initiated measures for their intensive conservation and management. Present paper deals with ecological status of coral reefs in the country and various national...

  9. Ocean acidification worse in coral reefs

    Science.gov (United States)

    Betz, Eric O.

    2014-12-01

    The rate of ocean acidification in coral reefs outpaces the rise in carbon dioxide (CO2) in Earth's atmosphere, indicating that anthropogenic carbon emissions alone are not to blame for the threat to coral reefs, a new study shows.

  10. Air-sea energy exchanges measured by eddy covariance during a localised coral bleaching event, Heron Reef, Great Barrier Reef, Australia

    Science.gov (United States)

    MacKellar, Mellissa C.; McGowan, Hamish A.

    2010-12-01

    Despite the widely claimed association between climate change and coral bleaching, a paucity of data exists relating to exchanges of heat, moisture and momentum between the atmosphere and the reef-water surface. We present in situ measurements of reef-water-air energy exchanges made using the eddy covariance method during a summer coral bleaching event at Heron Reef, Australia. Under settled, cloud-free conditions and light winds, daily net radiation exceeded 800 W m-2, with up to 95% of the net radiation during the morning partitioned into heating the water column, substrate and benthic cover including corals. Heating was exacerbated by a mid-afternoon low tide when shallow reef flat water reached 34°C and near-bottom temperatures 33°C, exceeding the thermal tolerance of corals, causing bleaching. Results suggest that local to synoptic scale meteorology, particularly clear skies, solar heating, light winds and the timing of low tide were the primary controls on coral bleaching.

  11. Spatial Variation in Background Mortality among Dominant Coral Taxa on Australia's Great Barrier Reef

    OpenAIRE

    Chiara Pisapia; Pratchett, Morgan S.

    2014-01-01

    Even in the absence of major disturbances (e.g., cyclones, bleaching), corals are consistently subject to high levels of background mortality, which undermines individual fitness and resilience of coral colonies. Partial mortality may impact coral response to climate change by reducing colony ability to recover between major acute stressors. This study quantified proportion of injured versus uninjured colonies (the prevalence of injuries) and instantaneous measures of areal extent of injuries...

  12. Long-term records of coral calcification across the central Great Barrier Reef: assessing the impacts of river runoff and climate change

    Science.gov (United States)

    D'Olivo, J. P.; McCulloch, M. T.; Judd, K.

    2013-12-01

    Calcification rates are reported for 41 long-lived Porites corals from 7 reefs, in an inshore to offshore transect across the central Great Barrier Reef (GBR). Over multi-decadal timescales, corals in the mid-shelf (1947-2008) and outer reef (1952-2004) regions of the GBR exhibit a significant increase in calcification of 10.9 ± 1.1 % (1.4 ± 0.2 % per decade; ±1 SE) and 11.1 ± 3.9 % (2.1 ± 0.8 % per decade), respectively, while inner-shelf (1930-2008), reefs show a decline of 4.6 ± 1.3 % (0.6 ± 0.2 % per decade). This long-term decline in calcification for the inner GBR is attributed to the persistent ongoing effects of high sediment/nutrients loads from wet season river discharges, compounded by the effects of thermal stress, especially during the 1998 bleaching event. For the recent period (1990-2008), our data show recovery from the 1998 bleaching event, with no significant trend in the rates of calcification (1.1 ± 2.0 %) for the inner reefs, while corals from the mid-shelf central GBR show a decline of 3.3 ± 0.9 %. These results are in marked contrast to the extreme reef-wide declines of 14.2 % reported by De'ath et al. (2009) for the period of 1990-2005. The De'ath et al. (2009) results are, however, found to be compromised by the inclusion of incomplete final years, duplicated records, together with a bias toward inshore reefs strongly affected by the 1998 bleaching. Our new findings nevertheless continue to raise concerns, with the inner-shelf reefs continuing to show long-term declines in calcification consistent with increased disturbance from land-based effects. In contrast, the more `pristine' mid- and outer-shelf reefs appear to be undergoing a transition from increasing to decreasing rates of calcification, possibly reflecting the effects of CO2-driven climate change. Our study highlights the importance of properly undertaken, regular assessments of coral calcification that are representative of the distinctive cross-shelf environments and

  13. Effects of Great Barrier Reef degradation on recreational reef-trip demand: a contingent behaviour approach

    OpenAIRE

    Kragt, Marit Ellen; Peter C. Roebeling; Ruijs, Arjan

    2009-01-01

    There is a growing concern that increased nutrient and sediment runoff from river catchments are a potential source of coral reef degradation. Degradation of reefs may affect the number of tourists visiting the reef and, consequently, the economic sectors that rely on healthy reefs for their income generation. This study uses a contingent behaviour approach to estimate the effect of reef degradation on demand for recreational dive and snorkel trips, for a case study of the Great Barrier Reef ...

  14. Nitrogen isotopic composition of organic matter from a 168 year-old coral skeleton: Implications for coastal nutrient cycling in the Great Barrier Reef Lagoon

    Science.gov (United States)

    Erler, Dirk V.; Wang, Xingchen T.; Sigman, Daniel M.; Scheffers, Sander R.; Martínez-García, Alfredo; Haug, Gerald H.

    2016-01-01

    Ongoing human activities are known to affect nitrogen cycling on coral reefs, but the full history of anthropogenic impact is unclear due to a lack of continuous records. We have used the nitrogen isotopic composition of skeleton-bound organic matter (CS-δ15N) in a coastal Porites coral from Magnetic Island in the Great Barrier Reef as a proxy for N cycle changes over a 168 yr period (1820-1987 AD). The Magnetic Island inshore reef environment is considered to be relatively degraded by terrestrial runoff; given prior CS-δ15N studies from other regions, there was an expectation of both secular change and oscillations in CS-δ15N since European settlement of the mainland in the mid 1800s. Surprisingly, CS-δ15N varied by less than 1.5‰ despite significant land use change on the adjacent mainland over the 168-yr measurement period. After 1930, CS-δ15N may have responded to changes in local river runoff, but the effect was weak. We propose that natural buffering against riverine nitrogen load in this region between 1820 and 1987 is responsible for the observed stability in CS-δ15N. In addition to coral derived skeletal δ15N, we also report, for the first time, δ15N measurements of non-coral derived organic N occluded within the coral skeleton, which appear to record significant changes in the nature of terrestrial N inputs. In the context of previous CS-δ15N records, most of which yield CS-δ15N changes of at least 5‰, the Magnetic Island coral suggests that the inherent down-core variability of the CS-δ15N proxy is less than 2‰ for Porites.

  15. Impact of Global Warming on Coral Reefs

    OpenAIRE

    Sirilak CHUMKIEW; Mullica JAROENSUTASINEE; Krisanadej JAROENSUTASINEE

    2011-01-01

    In this paper, we review coral reef responses to climate variability and discuss the possible mechanisms by which climate impacts the coral reef ecosystem. Effects of oceanographic variables such as sea temperature, turbulence, salinity, and nutrients on the coral reef are discussed in terms of their influence on coral growth, reproduction, mortality, acclimation and adaptation. Organisms tend to be limited to specific thermal ranges with experimental findings showing that sufficient oxygen s...

  16. COLLABORATIVE GUIDE: A REEF MANAGER'S GUIDE TO CORAL BLEACHING

    Science.gov (United States)

    Innovative strategies to conserve the world's coral reefs are included in a new guide released today by NOAA, and the Australian Great Barrier Reef Marine Park Authority, with author contributions from a variety of international partners from government agencies, non-governmental...

  17. Variability in reef connectivity in the Coral Triangle

    Science.gov (United States)

    Thompson, D. M.; Kleypas, J. A.; Castruccio, F. S.; Watson, J. R.; Curchitser, E. N.

    2015-12-01

    The Coral Triangle (CT) is not only the global center of marine biodiversity, it also supports the livelihoods of millions of people. Unfortunately, it is also considered the most threatened of all reef regions, with rising temperature and coral bleaching already taking a toll. Reproductive connectivity between reefs plays a critical role in the reef's capacity to recover after such disturbances. Thus, oceanographic modeling efforts to understand patterns of reef connectivity are essential to the effective design of a network of Marine Protected Areas (MPAs) to conserve marine ecosystems in the Coral Triangle. Here, we combine a Regional Ocean Modeling System developed for the Coral Triangle (CT-ROMS) with a Lagrangian particle tracking tool (TRACMASS) to investigate the probability of coral larval transport between reefs. A 47-year hindcast simulation (1960-2006) was used to investigate the variability in larval transport of a broadcasting coral following mass spawning events in April and September. Potential connectivity between reefs was highly variable and stochastic from year to year, emphasizing the importance of decadal or longer simulations in identifying connectivity patterns, key source and sink regions, and thus marine management targets for MPAs. The influence of temperature on realized connectivity (future work) may add further uncertainty to year-to-year patterns of connectivity between reefs. Nonetheless, the potential connectivity results we present here suggest that although reefs in this region are primarily self-seeded, rare long-distance dispersal may promote recovery and genetic exchange between reefs in the region. The spatial pattern of "subpopulations" based solely on the physical drivers of connectivity between reefs closely match regional patterns of biodiversity, suggesting that physical barriers to larval dispersal may be a key driver of reef biodiversity. Finally, 21st Century simulations driven by the Community Earth System Model (CESM

  18. Assessing community values for reducing agricultural emissions to improve water quality and protect coral health in the Great Barrier Reef

    OpenAIRE

    Windle, Jill; Rolfe, John

    2010-01-01

    Key policy issues relating to protection of the Great Barrier Reef from pollutants generated by agriculture are to identify when measures to improve water quality generate benefits to society that outweigh the costs of reducing pollutants. The research reported in this paper makes a key contribution in several key ways. First, it uses the improved science understanding about the links between management changes and reef health to bring together the analysis of costs and benefits of marginal c...

  19. Threshold Effects in Coral Reef Fisheries

    OpenAIRE

    Crépin, Anne Sophie

    2003-01-01

    Coral reefs may naturally flip between coral-dominated and algae-dominated states, when species' stocks trespass some threshold levels. This essay uses a stylized model of a coral reef to show how fishing may induce flips towards more algae-dominated states. Threshold effects have consequences for fisheries management, which are analyzed for open access fisheries and sole ownership.

  20. REEF MANAGER'S GUIDE TO CORAL BLEACHING

    Science.gov (United States)

    A Reef Manager's Guide to Coral Bleaching is the result of a collaborative effort by over 50 scientists and managers to: (1) engage in information-sharing in the areas of coral reef science and management for climate change and coral bleaching; and (2) compile a management tool ...

  1. 75 FR 48934 - Coral Reef Conservation Program Implementation Guidelines

    Science.gov (United States)

    2010-08-12

    ... National Oceanic and Atmospheric Administration RIN 0648-ZC19 Coral Reef Conservation Program... Implementation Guidelines for the Coral Reef Conservation Program. SUMMARY: This document provides NOAA's revised Grant Program Implementation Guidelines (Guidelines) for the Coral Reef Conservation Program (CRCP...

  2. Digital Reef Rugosity Estimates Coral Reef Habitat Complexity

    OpenAIRE

    Phillip Dustan; Orla Doherty; Shinta Pardede

    2013-01-01

    Ecological habitats with greater structural complexity contain more species due to increased niche diversity. This is especially apparent on coral reefs where individual coral colonies aggregate to give a reef its morphology, species zonation, and three dimensionality. Structural complexity is classically measured with a reef rugosity index, which is the ratio of a straight line transect to the distance a flexible chain of equal length travels when draped over the reef substrate; yet, other t...

  3. Lichen Monitoring Delineates Biodiversity on a Great Barrier Reef Coral Cay

    Directory of Open Access Journals (Sweden)

    Paul C. Rogers

    2015-05-01

    Full Text Available Coral islands around the world are threatened by changing climates. Rising seas, drought, and increased tropical storms are already impacting island ecosystems. We aim to better understand lichen community ecology of coral island forests. We used an epiphytic lichen community survey to gauge Pisonia (Pisonia grandis R.BR., which dominates forest conditions on Heron Island, Australia. Nine survey plots were sampled for lichen species presence and abundance, all tree diameters and species, GPS location, distance to forest-beach edge, and dominant forest type. Results found only six unique lichens and two lichen associates. A Multi-Response Permutation Procedures (MRPP test found statistically distinct lichen communities among forest types. The greatest group differences were between interior Pisonia and perimeter forest types. Ordinations were performed to further understand causes for distinctions in lichen communities. Significant explanatory gradients were distance to forest edge, tree density (shading, and Pisonia basal area. Each of these variables was negatively correlated with lichen diversity and abundance, suggesting that interior, successionally advanced, Pisonia forests support fewer lichens. Island edge and presumably younger forests—often those with greater tree diversity and sunlight penetration—supported the highest lichen diversity. Heron Island’s Pisonia-dominated forests support low lichen diversity which mirrors overall biodiversity patterns. Lichen biomonitoring may provide a valuable indicator for assessing island ecosystems for conservation purposes regionally.

  4. Coral Reef Watch, Hotspots, 50 km

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Coral Reef Watch provides Coral Bleaching hotspot maps derived from NOAA's Polar Operational Environmental Satellites (POES). This data provides global area...

  5. Framework of barrier reefs threatened by ocean acidification.

    Science.gov (United States)

    Comeau, Steeve; Lantz, Coulson A; Edmunds, Peter J; Carpenter, Robert C

    2016-03-01

    To date, studies of ocean acidification (OA) on coral reefs have focused on organisms rather than communities, and the few community effects that have been addressed have focused on shallow back reef habitats. The effects of OA on outer barrier reefs, which are the most striking of coral reef habitats and are functionally and physically different from back reefs, are unknown. Using 5-m long outdoor flumes to create treatment conditions, we constructed coral reef communities comprised of calcified algae, corals, and reef pavement that were assembled to match the community structure at 17 m depth on the outer barrier reef of Moorea, French Polynesia. Communities were maintained under ambient and 1200 μatm pCO2 for 7 weeks, and net calcification rates were measured at different flow speeds. Community net calcification was significantly affected by OA, especially at night when net calcification was depressed ~78% compared to ambient pCO2 . Flow speed (2-14 cm s(-1) ) enhanced net calcification only at night under elevated pCO2 . Reef pavement also was affected by OA, with dissolution ~86% higher under elevated pCO2 compared to ambient pCO2 . These results suggest that net accretion of outer barrier reef communities will decline under OA conditions predicted within the next 100 years, largely because of increased dissolution of reef pavement. Such extensive dissolution poses a threat to the carbonate foundation of barrier reef communities. PMID:26154126

  6. Coral reef research in India

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    area of the coastline gets lost every year. Some of the remedial measures to control erosion have also been indicated. The second article on Deep Sea Mining is of great potential value for the future. The polymetallic nodules which cover a very large... in the country who has developed interest on corals and coral reefs is the author of the present article Dr. M.V.M. Wafar. His article is followed by an account on microbes which play a very important ecological role in the marine environment, including...

  7. Cyanobacteria in Coral Reef Ecosystems: A Review

    Directory of Open Access Journals (Sweden)

    L. Charpy

    2012-01-01

    Full Text Available Cyanobacteria have dominated marine environments and have been reef builders on Earth for more than three million years (myr. Cyanobacteria still play an essential role in modern coral reef ecosystems by forming a major component of epiphytic, epilithic, and endolithic communities as well as of microbial mats. Cyanobacteria are grazed by reef organisms and also provide nitrogen to the coral reef ecosystems through nitrogen fixation. Recently, new unicellular cyanobacteria that express nitrogenase were found in the open ocean and in coral reef lagoons. Furthermore, cyanobacteria are important in calcification and decalcification. All limestone surfaces have a layer of boring algae in which cyanobacteria often play a dominant role. Cyanobacterial symbioses are abundant in coral reefs; the most common hosts are sponges and ascidians. Cyanobacteria use tactics beyond space occupation to inhibit coral recruitment. Cyanobacteria can also form pathogenic microbial consortia in association with other microbes on living coral tissues, causing coral tissue lysis and death, and considerable declines in coral reefs. In deep lagoons, coccoid cyanobacteria are abundant and are grazed by ciliates, heteroflagellates, and the benthic coral reef community. Cyanobacteria produce metabolites that act as attractants for some species and deterrents for some grazers of the reef communities.

  8. Flushing of Bowden Reef lagoon, Great Barrier Reef

    Science.gov (United States)

    Wolanski, Eric; King, Brian

    1990-12-01

    Field and numerical studies were undertaken in 1986 and 1987 of the water circulation around and over Bowden Reef, a 5-km long kidney-shaped coral reef lagoon system in the Great Barrier Reef. In windy conditions, the flushing of the lagoon was primarily due to the intrusion into the lagoon of topographically induced tidal eddies generated offshore. In calm weather, such eddies did not prevail and lagoon flushing was much slower. The observed currents at sites a few kilometres apart in inter-reefal waters, have a significant horizontal shear apparently due to the complex circulation in the reef matrix. Under such conditions, sensitivity tests demonstrate the importance of including this shear in the specification of open boundary conditions of numerical models of the hydrodynamics around reefs. Contrary to established practice, the water circulation around a coral reef should not be modelled by assuming reefs are hydrodynamically isolated from surrounding ones. Little improvement appears likely in the reliability of reef-scale numerical models until the inter-reefal shear can be reliably incorporated in such models.

  9. Dynamic fragility of oceanic coral reef ecosystems

    OpenAIRE

    Graham, Nicholas A. J.; Wilson, Shaun K.; Jennings, Simon; Polunin, Nicholas V.C.; Bijoux, Jude P.; Robinson, Jan

    2006-01-01

    As one of the most diverse and productive ecosystems known, and one of the first ecosystems to exhibit major climate-warming impacts (coral bleaching), coral reefs have drawn much scientific attention to what may prove to be their Achilles heel, the thermal sensitivity of reef-building corals. Here we show that climate change-driven loss of live coral, and ultimately structural complexity, in the Seychelles results in local extinctions, substantial reductions in species richness, reduced taxo...

  10. Kenya – Coral Reef Resilience Studies.

    OpenAIRE

    Obura, David O.

    2005-01-01

    Activities supported by CORDIO in Kenya started in 1999, focusing on a long term coral reef monitoring programme in the Kiunga Marine Reserve to track recovery of reefs from the 1998 El Niño coral bleaching event (Obura, 1999). In addition, a range of biological studies were supported (Obura et al., 2000), including studies on temperature/UV interactions, benthic community structure, coral recruitment and bleaching, coral/zooxanthellae dynamics, macro- and micro-algal community structure and ...

  11. Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types

    Science.gov (United States)

    Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

    2014-01-01

    In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy. PMID:24845540

  12. Effects of Great Barrier Reef Degradation on Recreational Demand: A Contingent Behaviour Approach

    OpenAIRE

    Peter C. Roebeling; M.E. Kragt; Ruijs, A.

    2006-01-01

    Agricultural run-off from the Great Barrier Reef catchment area may cause degradation of coral reefs, affecting the tourism sector that relies on healthy reefs for its income generation. A Contingent Behaviour approach is used to determine the effect of reef degradation on demand for recreational dive and snorkel trips, for a case study of the Great Barrier Reef (GBR) in Australia. We assessed how reef degradation affects GBR tourism and to what extent reef-trip demand depends on the visitors...

  13. 78 FR 67128 - Coral Reef Conservation Program; Meeting

    Science.gov (United States)

    2013-11-08

    ... National Oceanic and Atmospheric Administration Coral Reef Conservation Program; Meeting AGENCY: Coral Reef... of public comment. SUMMARY: Notice is hereby given of a public meeting of the U.S. Coral Reef Task... to do so. Established by Presidential Executive Order 13089 in 1998, the U.S. Coral Reef Task...

  14. National Coral Reef Monitoring Program: Assessment of coral reef communities in Puerto Rico using the Coral Demographics method

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Coral Demographic method is one of two benthic surveys conducted in Puerto Rico as part of the National Coral Reef Monitoring Program (NCRMP). The coral...

  15. Modeling Reef Hydrodynamics to Predict Coral Bleaching

    Science.gov (United States)

    Bird, James; Steinberg, Craig; Hardy, Tom

    2005-11-01

    The aim of this study is to use environmental physics to predict water temperatures around and within coral reefs. Anomalously warm water is the leading cause for mass coral bleaching; thus a clearer understanding of the oceanographic mechanisms that control reef water temperatures will enable better reef management. In March 1998 a major coral bleaching event occurred at Scott Reef, a 40 km-wide lagoon 300 km off the northwest coast of Australia. Meteorological and coral cover observations were collected before, during, and after the event. In this study, two hydrodynamic models are applied to Scott Reef and validated against oceanographic data collected between March and June 2003. The models are then used to hindcast the reef hydrodynamics that led up to the 1998 bleaching event. Results show a positive correlation between poorly mixed regions and bleaching severity.

  16. Holocene development of the Belize Barrier Reef

    Science.gov (United States)

    Gischler, Eberhard; Hudson, J. Harold

    2004-02-01

    Previously, knowledge of the Holocene development of the Belize Barrier Reef (BBR)—the largest reef system in the Atlantic Ocean—was limited to one location (Carrie Bow Cay). We present new data from 11 rotary drill cores taken at 9 locations and 36 radiometric ages that indicate that the BBR was established from >8.26 to 6.68 ky BP on Pleistocene reef limestones, presumably deposited during oxygen isotope stage 5. The nonsynchronous start of Holocene reef growth was a consequence of variation in elevation of antecedent topography, largely controlled by underlying NNE-trending structures. From north to south, Pleistocene elevation decreases along these structural trends, probably reflecting differential subsidence and variations in karst topography. Reef anatomy is characterized by three facies. In order of decreasing abundance, these facies are represented by corals (mainly Acropora palmata and members of the Montastraea annularis group), by unconsolidated sand and rubble, and by well-cemented coral grainstones-rudstones. Holocene reef accumulation rates average 3.25 m/ky. The degree of reef consolidation is negatively correlated with Holocene thicknesses, indicating that slowly growing reefs are better cemented than fast growing ones. We present a Holocene sea-level curve for Belize based on 36 dates from this study and 33 dates from our previous studies in the area.

  17. Fungi and their role in corals and coral reef ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Ravindran, J.

    , nutraceutical, enzymes, cosmetics, pesticides and other novel commercial products. Coral reefs contain diversity of sessile animals, such as corals, sponges, tunicates, molluscs, bryozoan and echinoderms. These sessile animals have developed unique chemical... Ainsworth TD, Thurber RV, Gates RD (2010) The future of coral reefs: a microbial perspective. Trends Ecol Evol 25:233-240 Alker AP, Smith GW, Kim K (2001) Characterization of Aspergillus sydowii (Thom et Church), a fungal pathogen of Caribbean sea fan...

  18. Coral reefs and their management in Tanzania

    OpenAIRE

    Wagner, G.M.

    2004-01-01

    Coral reefs are very important in Tanzania, both ecologically and socio-economically, as major fishing grounds and tourist attractions. Numerous fringing and patch reefs are located along about two-thirds of Tanzania’s coastline. These reefs have been partially to severely degraded by human (primarily destructive fishing practices) and natural (particularly coral bleaching) causes. These immediate human causes have been brought about by various socioeconomic root causes, particularly poverty ...

  19. Linking coral reef health and human welfare

    OpenAIRE

    Walsh, Sheila Marie

    2009-01-01

    Globally, 7̃00 million people depend on coral reef goods and services. However, over half of coral reefs are threatened due to global warming, fishing, and nutrient pollution. Using ecological and economic methods, I evaluated 1) the ecosystem-scale effects of fishing and nutrients, 2) the effects of fishing on condition and reproduction in a reef fish community, and 3) an integrated conservation and development program (ICDP). The Republic of Kiribati, Central Pacific, provided two natural e...

  20. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    Directory of Open Access Journals (Sweden)

    Jacob L Johansen

    Full Text Available Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.. Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m, mid-slope (6 m and deep-slope (9 m depth of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m and frequency (0.54 to 0.20 Hz, emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  1. Assessing community values for reducing agricultural emissions to improve water quality and protect coral health in the Great Barrier Reef

    Science.gov (United States)

    Rolfe, John; Windle, Jill

    2011-12-01

    Policymakers wanting to increase protection of the Great Barrier Reef from pollutants generated by agriculture need to identify when measures to improve water quality generate benefits to society that outweigh the costs involved. The research reported in this paper makes a contribution in several ways. First, it uses the improved science understanding about the links between management changes and reef health to bring together the analysis of costs and benefits of marginal changes, helping to demonstrate the appropriate way of addressing policy questions relating to reef protection. Second, it uses the scientific relationships to frame a choice experiment to value the benefits of improved reef health, with the results of mixed logit (random parameter) models linking improvements explicitly to changes in "water quality units." Third, the research demonstrates how protection values are consistent across a broader population, with some limited evidence of distance effects. Fourth, the information on marginal costs and benefits that are reported provide policymakers with information to help improve management decisions. The results indicate that while there is potential for water quality improvements to generate net benefits, high cost water quality improvements are generally uneconomic. A major policy implication is that cost thresholds for key pollutants should be set to avoid more expensive water quality proposals being selected.

  2. Asexual reproduction does not produce clonal populations of the brooding coral Pocillopora damicornis on the Great Barrier Reef, Australia

    Science.gov (United States)

    Sherman, C. D. H.; Ayre, D. J.; Miller, K. J.

    2006-03-01

    We have investigated the relationship between genotypic diversity, the mode of production of brooded larvae and disturbance in a range of reef habitats, in order to resolve the disparity between the reproductive mode and population structure reported for the brooding coral Pocillopora damicornis. Within 14 sites across six habitats, the ratio of the observed ( G o) to the expected ( G e) genotypic diversity ranged from 69 to 100% of that expected for random mating. At three other sites in two habitats the G o /G e ranged from 35 to 53%. Two of these sites were recently bleached, suggesting that asexual recruitment may be favoured after disturbance. Nevertheless, our data suggest that brooded larvae, from each of five habitats surveyed, were asexually produced. While clonal recruitment may be important in disturbed habitats, the lack of clonality detected, both in this and earlier surveys of 40 other sites, implies that a disturbance is normally insufficient to explain this species’ continued investment in clonal reproduction.

  3. Coral mucus functions as an energy carrier and particle trap in the reef ecosystem

    DEFF Research Database (Denmark)

    Wild, C.; Huettel, M.; Klueter, A.;

    2004-01-01

    Zooxanthellae, endosymbiotic algae of reef-building corals, substantially contribute to the high gross primary production of coral reefs(1), but corals exude up to half of the carbon assimilated by their zooxanthellae as mucus(2,3). Here we show that released coral mucus efficiently traps organic...... matter from the water column and rapidly carries energy and nutrients to the reef lagoon sediment, which acts as a biocatalytic mineralizing filter. In the Great Barrier Reef, the dominant genus of hard corals, Acropora, exudes up to 4.8 litres of mucus per square metre of reef area per day. Between 56......% and 80% of this mucus dissolves in the reef water, which is filtered through the lagoon sands. Here, coral mucus is degraded at a turnover rate of at least 7% per hour. Detached undissolved mucus traps suspended particles, increasing its initial organic carbon and nitrogen content by three orders of...

  4. Coral reef invertebrate microbiomes correlate with the presence of photosymbionts

    OpenAIRE

    Bourne, David G.; Dennis, Paul G.; Uthicke, Sven; Soo, Rochelle M; Tyson, Gene W; Nicole WEBSTER

    2013-01-01

    Coral reefs provide habitat for an array of marine invertebrates that host symbiotic microbiomes. Photosynthetic symbionts including Symbiodinium dinoflagellates and diatoms potentially influence the diversity of their host-associated microbiomes by releasing carbon-containing photosynthates and other organic compounds that fuel microbial metabolism. Here we used 16S ribosomal RNA (rRNA) gene amplicon pyrosequencing to characterise the microbiomes of 11 common Great Barrier Reef marine invert...

  5. Sediments and herbivory as sensitive indicators of coral reef degradation

    Directory of Open Access Journals (Sweden)

    Christopher H. R. Goatley

    2016-03-01

    Full Text Available Around the world, the decreasing health of coral reef ecosystems has highlighted the need to better understand the processes of reef degradation. The development of more sensitive tools, which complement traditional methods of monitoring coral reefs, may reveal earlier signs of degradation and provide an opportunity for pre-emptive responses. We identify new, sensitive metrics of ecosystem processes and benthic composition that allow us to quantify subtle, yet destabilizing, changes in the ecosystem state of an inshore coral reef on the Great Barrier Reef. Following severe climatic disturbances over the period 2011-2012, the herbivorous reef fish community of the reef did not change in terms of biomass or functional groups present. However, fish-based ecosystem processes showed marked changes, with grazing by herbivorous fishes declining by over 90%. On the benthos, algal turf lengths in the epilithic algal matrix increased more than 50% while benthic sediment loads increased 37-fold. The profound changes in processes, despite no visible change in ecosystem state, i.e., no shift to macroalgal dominance, suggest that although the reef has not undergone a visible regime-shift, the ecosystem is highly unstable, and may sit on an ecological knife-edge. Sensitive, process-based metrics of ecosystem state, such as grazing or browsing rates thus appear to be effective in detecting subtle signs of degradation and may be critical in identifying ecosystems at risk for the future.

  6. Real-time PCR reveals a high incidence of Symbiodinium clade D at low levels in four scleractinian corals across the Great Barrier Reef : implications for symbiont shuffling

    NARCIS (Netherlands)

    Mieog, J. C.; van Oppen, M. J. H.; Cantin, N. E.; Stam, W. T.; Olsen, J. L.

    2007-01-01

    Reef corals form associations with an array of genetically and physiologically distinct endosymbionts from the genus Symbiodinium. Some corals harbor different clades of symbionts simultaneously, and over time the relative abundances of these clades may change through a process called symbiont shuff

  7. NOAA's Coral Reef Conservation Program: 2016 projects to address coral reef conservation issues

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2016 the following projects will take place to address aspects of coral reef conservation: Enhancing Management of Pacific ESA-listed Corals with Improved...

  8. Biological impacts of oil pollution: coral reefs

    International Nuclear Information System (INIS)

    Coral reefs are the largest structures made by living things and exist as extremely productive ecosystems in tropical and sub-tropical areas of the world. Their location in nearshore waters means that there is a potential danger to corals from tanker accidents, refinery operations, oil exploration and production. There are now a number of published scientific papers concerning the effects of oils on corals. This report summarises and interprets the findings, and provides background information on the structure and ecology of coral reefs. Clean-up options and their implications are discussed in the light of the latest evidence from case histories and field experiments. (author)

  9. Marine protected areas increase resilience among coral reef communities.

    Science.gov (United States)

    Mellin, Camille; Aaron MacNeil, M; Cheal, Alistair J; Emslie, Michael J; Julian Caley, M

    2016-06-01

    With marine biodiversity declining globally at accelerating rates, maximising the effectiveness of conservation has become a key goal for local, national and international regulators. Marine protected areas (MPAs) have been widely advocated for conserving and managing marine biodiversity yet, despite extensive research, their benefits for conserving non-target species and wider ecosystem functions remain unclear. Here, we demonstrate that MPAs can increase the resilience of coral reef communities to natural disturbances, including coral bleaching, coral diseases, Acanthaster planci outbreaks and storms. Using a 20-year time series from Australia's Great Barrier Reef, we show that within MPAs, (1) reef community composition was 21-38% more stable; (2) the magnitude of disturbance impacts was 30% lower and (3) subsequent recovery was 20% faster that in adjacent unprotected habitats. Our results demonstrate that MPAs can increase the resilience of marine communities to natural disturbance possibly through herbivory, trophic cascades and portfolio effects. PMID:27038889

  10. Coral Reef Watch, Temperature Anomaly, 50 km

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Coral Reef Watch distributes SST anomaly data using a combination of the POES AVHRR Global Area Coverage data, and data from a climatological database. AVHRR...

  11. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    Science.gov (United States)

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  12. Coral Reef Watch, Nighttime Temperature, 50 km

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Coral Reef Watch provides sea surface temperature (SST) products derived from NOAA's Polar Operational Environmental Satellites (POES). This data provides...

  13. Ecological Processes and Contemporary Coral Reef Management

    OpenAIRE

    Angela Dikou

    2010-01-01

    Top-down controls of complex foodwebs maintain the balance among the critical groups of corals, algae, and herbivores, thus allowing the persistence of corals reefs as three-dimensional, biogenic structures with high biodiversity, heterogeneity, resistance, resilience and connectivity, and the delivery of essential goods and services to societies. On contemporary reefs world-wide, however, top-down controls have been weakened due to reduction in herbivory levels (overfishing or disease outbre...

  14. Turf algae-mediated coral damage in coastal reefs of Belize, Central America

    KAUST Repository

    Wild, Christian

    2014-09-16

    Many coral reefs in the Caribbean experienced substantial changes in their benthic community composition during the last decades. This often resulted in phase shifts from scleractinian coral dominance to that by other benthic invertebrate or algae. However, knowledge about how the related role of coral-algae contacts may negatively affect corals is scarce. Therefore, benthic community composition, abundance of algae grazers, and the abundance and character of coral-algae contacts were assessed in situ at 13 Belizean reef sites distributed along a distance gradient to the Belizean mainland (12–70 km): Mesoamerican Barrier Reef (inshore), Turneffe Atoll (inner and outer midshore), and Lighthouse Reef (offshore). In situ surveys revealed significantly higher benthic cover by scleractinian corals at the remote Lighthouse Reef (26–29%) when compared to the other sites (4–19%). The abundance of herbivorous fish and the sea urchin Diadema antillarum significantly increased towards the offshore reef sites, while the occurrence of direct coral-algae contacts consequently increased significantly with decreasing distance to shore. About 60% of these algae contacts were harmful (exhibiting coral tissue damage, pigmentation change, or overgrowth) for corals (mainly genera Orbicella and Agaricia), particularly when filamentous turf algae were involved. These findings provide support to the hypothesis that (turf) algae-mediated coral damage occurs in Belizean coastal, near-shore coral reefs.

  15. Turf algae-mediated coral damage in coastal reefs of Belize, Central America

    Directory of Open Access Journals (Sweden)

    Christian Wild

    2014-09-01

    Full Text Available Many coral reefs in the Caribbean experienced substantial changes in their benthic community composition during the last decades. This often resulted in phase shifts from scleractinian coral dominance to that by other benthic invertebrate or algae. However, knowledge about how the related role of coral-algae contacts may negatively affect corals is scarce. Therefore, benthic community composition, abundance of algae grazers, and the abundance and character of coral-algae contacts were assessed in situ at 13 Belizean reef sites distributed along a distance gradient to the Belizean mainland (12–70 km: Mesoamerican Barrier Reef (inshore, Turneffe Atoll (inner and outer midshore, and Lighthouse Reef (offshore. In situ surveys revealed significantly higher benthic cover by scleractinian corals at the remote Lighthouse Reef (26–29% when compared to the other sites (4–19%. The abundance of herbivorous fish and the sea urchin Diadema antillarum significantly increased towards the offshore reef sites, while the occurrence of direct coral-algae contacts consequently increased significantly with decreasing distance to shore. About 60% of these algae contacts were harmful (exhibiting coral tissue damage, pigmentation change, or overgrowth for corals (mainly genera Orbicella and Agaricia, particularly when filamentous turf algae were involved. These findings provide support to the hypothesis that (turf algae-mediated coral damage occurs in Belizean coastal, near-shore coral reefs.

  16. U-Th age distribution of coral fragments from multiple rubble ridges within the Frankland Islands, Great Barrier Reef: Implications for past storminess history

    Science.gov (United States)

    Liu, Entao; Zhao, Jian-xin; Feng, Yue-xing; Leonard, Nicole D.; Clark, Tara R.; Roff, George

    2016-07-01

    Prograded coral rubble ridges have been widely used as archives for reconstructing long-term storm or storminess history. Chronologies of ridge systems in previous studies are often based on a limited number of low-resolution radiocarbon or optically-stimulated luminescence (OSL) ages per ridge (usually only one age per ridge), which carry intrinsic age uncertainties and make interpretation of storm histories problematic. To test the fidelity of storm ridges as palaeo-storm archives, we used high-precision U-Th dating to examine whether different samples from a single ridge are temporally constrained. We surveyed three transects of ridge systems from two continental islands (Normanby Island and High Island) within the Frankland Islands, Great Barrier Reef (GBR), and obtained 96 U-Th dates from coral rubble samples collected from within and between different ridges. Our results revealed significant differences in age ranges between the two islands. The steeper and more defined rubble ridges present on Normanby Island revealed that the majority of U-Th ages (over 60%) from a single ridge clustered within a narrow age range (∼100 years). By contrast, the lower and less defined ridges on High Island, which were more likely formed during both storm and non-storm high-energy events, revealed significant scatter in age distribution (>>200 years) with no notable clustering. The narrower age ranges obtained from the steeper and more defined rubble ridges suggest that previous approaches of using either limited samples from a single ridge or low-precision dating methods to establish chronologies are generally valid at centennial to millennial timescales, although caution must be taken to use such approaches for storm history reconstruction on shorter timescales (e.g. decadal). The correlation between U-Th mortality ages of coral rubble and historical stormy periods highlights the possibility of using coral rubble age distribution from rubble ridges to reconstruct the long

  17. Environmental Economics and Coral Reef Management: Needs and Opportunities for Research in SE Asia

    OpenAIRE

    H. Jack Ruitenbeek

    1999-01-01

    From 1994 to 1998, EEPSEA approved some 65 research projects in environmental economic analysis. Of these, 38 related to "brown" environmental issues, 23 to "green" issues, and four to other issues. None pertained to coral reefs. This relative dearth of coral reef analysis is mirrored in the broader literature; only seven separate environmental economic studies have been undertaken that address policy concerns in SE Asia or nearby areas on Papua New Guineas and Australias Great Barrier Reef. ...

  18. A review of coral reef restoration techniques

    NARCIS (Netherlands)

    Meesters, H.W.G.; Smith, S.R.; Becking, L.E.

    2015-01-01

    In this review the following three reef restoration techniques are discussed: 1. Coral gardening, 2. Larval seeding, and 3. Reef balls. In this report we provide a description of each method and review the pro/cons using the following criteria: 1. Survival of fragments and larvae before transplantat

  19. The reality, use and potential for cryopreservation of coral reefs.

    Science.gov (United States)

    Hagedorn, Mary; Spindler, Rebecca

    2014-01-01

    Throughout the world coral reefs are being degraded at unprecedented rates. Locally, reefs are damaged by pollution, nutrient overload and sedimentation from out-dated land-use, fishing and mining practices. Globally, increased greenhouse gases are warming and acidifying oceans, making corals more susceptible to stress, bleaching and newly emerging diseases. The coupling of climate change impacts and local anthropogenic stressors has caused a widespread and well-recognized reef crisis. Although in situ conservation practices, such as the establishment and enforcement of marine protected areas, reduce these stressors and may help slow the loss of genetic diversity on reefs, the global effects of climate change will continue to cause population declines. Gamete cryopreservation has already acted as an effective insurance policy to maintain the genetic diversity of many wildlife species, but has only just begun to be explored for coral. Already we have had a great deal of success with cryopreserving sperm and larval cells from a variety of coral species. Building on this success, we have now begun to establish genetic banks using frozen samples, to help offset these threats to the Great Barrier Reef and other areas. PMID:25091915

  20. Rapid Smothering of Coral Reef Organisms by Muddy Marine Snow

    Science.gov (United States)

    Fabricius, K. E.; Wolanski, E.

    2000-01-01

    Estuarine mud, when resuspended in nutrient-rich near-shore water, aggregates to marine snow, and within minutes to hours can exert detrimental or even lethal effects on small coral reef organisms. In a pilot study, estuarine mud was suspended in near-shore and off-shore waters of the Great Barrier Reef to a final concentration of 170 mg l -1. The short-term responses of a coral ( Acropora sp.) and coral-inhabiting barnacles (subfamily Pyrgomatidae), exposed to either near-shore or off-shore water, were microscopically observed and video recorded. In the off-shore water treatment, flocculation was minor, and aggregate sizes were c. 50 μm. The organisms were able to clean themselves from these small settling aggregates at low siltation (mucus only at high siltation (4-5 mg cm -2). In contrast, in near-shore, nutrient-enriched waters, the suspended mud aggregated into large sticky flocs of marine snow (200-2000 μm diameter). The organisms responded to a thin coat of deposited flocs with vigorous cleaning by cirri and tentacle beating. After 5 min struggle, the barnacle stopped moving, calanoid copepods were entangled in the aggregates, and thick layers of mucus were exuded by the coral polyps. Both barnacle and copepods died after coral reefs. Enhanced nutrient concentrations are known to contribute to enhance biologically mediated flocculation. This pilot study suggests that the concentration of suspended mud, and extent of stickiness and flocculation, can synergistically affect reef benthos organisms after short exposure. The enclosed macro video recordings clearly visualize these effects, and help convey the important implications for managers: that inshore reefs of the Great Barrier Reef cannot be sustainably managed without managing the adjacent land.

  1. Doom and boom on a resilient reef: climate change, algal overgrowth and coral recovery.

    Directory of Open Access Journals (Sweden)

    Guillermo Diaz-Pulido

    Full Text Available BACKGROUND: Coral reefs around the world are experiencing large-scale degradation, largely due to global climate change, overfishing, diseases and eutrophication. Climate change models suggest increasing frequency and severity of warming-induced coral bleaching events, with consequent increases in coral mortality and algal overgrowth. Critically, the recovery of damaged reefs will depend on the reversibility of seaweed blooms, generally considered to depend on grazing of the seaweed, and replenishment of corals by larvae that successfully recruit to damaged reefs. These processes usually take years to decades to bring a reef back to coral dominance. METHODOLOGY/PRINCIPAL FINDINGS: In 2006, mass bleaching of corals on inshore reefs of the Great Barrier Reef caused high coral mortality. Here we show that this coral mortality was followed by an unprecedented bloom of a single species of unpalatable seaweed (Lobophora variegata, colonizing dead coral skeletons, but that corals on these reefs recovered dramatically, in less than a year. Unexpectedly, this rapid reversal did not involve reestablishment of corals by recruitment of coral larvae, as often assumed, but depended on several ecological mechanisms previously underestimated. CONCLUSIONS/SIGNIFICANCE: These mechanisms of ecological recovery included rapid regeneration rates of remnant coral tissue, very high competitive ability of the corals allowing them to out-compete the seaweed, a natural seasonal decline in the particular species of dominant seaweed, and an effective marine protected area system. Our study provides a key example of the doom and boom of a highly resilient reef, and new insights into the variability and mechanisms of reef resilience under rapid climate change.

  2. Assessment of Coral Reef Degradation in Tanzania: Results of Coral Reef Monitoring 1999

    OpenAIRE

    Muhando, C.A.; Mohammed, M.S.; Machano, H.

    1999-01-01

    Coral reefs play a crucial role in the well being of coastal communities in Tanzania (Johnstone et al., 1998; Muhando, 1999). However, despite their usefulness, coral reefs are being degraded by destructive anthropogenic activities (Salm et al., 1998) and natural causes (e.g., competition, predation, diseases, bleaching, etc.). The coral bleaching and mortality event of March - June 1998 was the most serious natural calamity ever recorded in the Indian Ocean (Wilkinson, et al., 1999). Several...

  3. Can we measure beauty? Computational evaluation of coral reef aesthetics

    NARCIS (Netherlands)

    A.F. Haas; M. Guibert; A. Foerschner; T. Co; S. Calhoun; E. George; M. Hatay; E. Dinsdale; S.A. Sandin; J.E. Smith; M.J.A. Vermeij; B. Felts; P. Dustan; P. Salamon; F. Rohwer

    2015-01-01

    The natural beauty of coral reefs attracts millions of tourists worldwide resulting in substantial revenues for the adjoining economies. Although their visual appearance is a pivotal factor attracting humans to coral reefs current monitoring protocols exclusively target biogeochemical parameters, ne

  4. A species pair of Bivesicula Yamaguti, 1934 (Trematoda: Bivesiculidae) in unrelated Great Barrier Reef fishes: implications for the basis of speciation in coral reef fish trematodes.

    Science.gov (United States)

    Trieu, Nancy; Cutmore, Scott C; Miller, Terrence L; Cribb, Thomas H

    2015-07-01

    Combined morphological and molecular analysis shows that a species of Bivesicula Yamaguti, 1934 from four species of Apogonidae Günther [Nectamia fusca (Quoy & Gaimard), Ostorhinchus angustatus (Smith & Radcliffe), O. cookii (Macleay) and Taeniamia fucata (Cantor)] on the Great Barrier Reef is morphologically similar to, but clearly distinct from B. unexpecta Cribb, Bray & Barker, 1994 which infects a sympatric pomacentrid, Acanthochromis polyacanthus (Bleeker). Bivesicula neglecta n. sp. is proposed for the form from apogonids. Novel ITS2 rDNA sequences generated for the two species differ at just one consistent base position, implying that the two species are closely related. The combination of their close relationship, high but distinct specificity and co-occurrence suggests that speciation was driven by a recent host switching event enabled by similar dietary ecomorphology. PMID:26063300

  5. Bacterial communities of two ubiquitous Great Barrier Reef corals reveals both site- and species-specificity of common bacterial associates.

    Directory of Open Access Journals (Sweden)

    E Charlotte E Kvennefors

    Full Text Available BACKGROUND: Coral-associated bacteria are increasingly considered to be important in coral health, and altered bacterial community structures have been linked to both coral disease and bleaching. Despite this, assessments of bacterial communities on corals rarely apply sufficient replication to adequately describe the natural variability. Replicated data such as these are crucial in determining potential roles of bacteria on coral. METHODOLOGY/PRINCIPAL FINDINGS: Denaturing Gradient Gel Electrophoresis (DGGE of the V3 region of the 16S ribosomal DNA was used in a highly replicated approach to analyse bacterial communities on both healthy and diseased corals. Although site-specific variations in the bacterial communities of healthy corals were present, host species-specific bacterial associates within a distinct cluster of gamma-proteobacteria could be identified, which are potentially linked to coral health. Corals affected by "White Syndrome" (WS underwent pronounced changes in their bacterial communities in comparison to healthy colonies. However, the community structure and bacterial ribotypes identified in diseased corals did not support the previously suggested theory of a bacterial pathogen as the causative agent of the syndrome. CONCLUSIONS/SIGNIFICANCE: This is the first study to employ large numbers of replicated samples to assess the bacterial communities of healthy and diseased corals, and the first culture-independent assessment of bacterial communities on WS affected Acroporid corals on the GBR. Results indicate that a minimum of 6 replicate samples are required in order to draw inferences on species, spatial or health-related changes in community composition, as a set of clearly distinct bacterial community profiles exist in healthy corals. Coral bacterial communities may be both site and species specific. Furthermore, a cluster of gamma-proteobacterial ribotypes may represent a group of specific common coral and marine

  6. Sediment suppresses herbivory across a coral reef depth gradient

    OpenAIRE

    Goatley, Christopher H. R.; Bellwood, David R.

    2012-01-01

    Sediments are a ubiquitous feature of all coral reefs, yet our understanding of how they affect complex ecological processes on coral reefs is limited. Sediment in algal turfs has been shown to suppress herbivory by coral reef fishes on high-sediment, low-herbivory reef flats. Here, we investigate the role of sediment in suppressing herbivory across a depth gradient (reef base, crest and flat) by observing fish feeding following benthic sediment reductions. We found that sediment suppresses h...

  7. Coral Reefs: A Gallery Program, Grades 7-12.

    Science.gov (United States)

    National Aquarium in Baltimore, MD. Dept. of Education.

    Gallery classes at the National Aquarium in Baltimore give the opportunity to study specific aquarium exhibits which demonstrate entire natural habitats. The coral reef gallery class features the gigantic western Atlantic coral reef (325,000 gallons) with over 1,000 fish. The exhibit simulates a typical Caribbean coral reef and nearby sandy…

  8. A too acid world for coral reefs

    International Nuclear Information System (INIS)

    While briefly presenting how corals grow and exchange with their environment and after having recalled that temperature increase was already a threat for them, this article outlines that ocean acidification is now considered as another danger. This acidification is due to the dissolution in sea water of CO2 produced by human activities. This entails a slower calcification which is the process by which corals grow their skeleton. But, some researches showed that some corals manage to survive normally in such acid conditions, and even without skeleton for some other species. Anyhow, coral reefs will tend to disappear with environmental and socio-economical consequences

  9. Ecological Processes and Contemporary Coral Reef Management

    Directory of Open Access Journals (Sweden)

    Angela Dikou

    2010-05-01

    Full Text Available Top-down controls of complex foodwebs maintain the balance among the critical groups of corals, algae, and herbivores, thus allowing the persistence of corals reefs as three-dimensional, biogenic structures with high biodiversity, heterogeneity, resistance, resilience and connectivity, and the delivery of essential goods and services to societies. On contemporary reefs world-wide, however, top-down controls have been weakened due to reduction in herbivory levels (overfishing or disease outbreak while bottom-up controls have increased due to water quality degradation (increase in sediment and nutrient load and climate forcing (seawater warming and acidification leading to algal-dominated alternate benthic states of coral reefs, which are indicative of a trajectory towards ecological extinction. Management to reverse common trajectories of degradation for coral reefs necessitates a shift from optimization in marine resource use and conservation towards building socio-economic resilience into coral reef systems while attending to the most manageable human impacts (fishing and water quality and the global-scale causes (climate change.

  10. Coral reef evolution on rapidly subsiding margins

    Science.gov (United States)

    Webster, J.M.; Braga, J.C.; Clague, D.A.; Gallup, C.; Hein, J.R.; Potts, D.C.; Renema, W.; Riding, R.; Riker-Coleman, K.; Silver, E.; Wallace, L.M.

    2009-01-01

    A series of well-developed submerged coral reefs are preserved in the Huon Gulf (Papua New Guinea) and around Hawaii. Despite different tectonics settings, both regions have experienced rapid subsidence (2-6??m/ka) over the last 500??ka. Rapid subsidence, combined with eustatic sea-level changes, is responsible for repeated drowning and backstepping of coral reefs over this period. Because we can place quantitative constraints on these systems (i.e., reef drowning age, eustatic sea-level changes, subsidence rates, accretion rates, basement substrates, and paleobathymetry), these areas represent unique natural laboratories for exploring the roles of tectonics, reef accretion, and eustatic sea-level changes in controlling the evolution of individual reefs, as well as backstepping of the entire system. A review of new and existing bathymetric, radiometric, sedimentary facies and numerical modeling data indicate that these reefs have had long, complex growth histories and that they are highly sensitive, recording drowning not only during major deglaciations, but also during high-frequency, small-amplitude interstadial and deglacial meltwater pulse events. Analysis of five generalized sedimentary facies shows that reef drowning is characterized by a distinct biological and sedimentary sequence. Observational and numerical modeling data indicate that on precessional (20??ka) and sub-orbital timescales, the rate and amplitude of eustatic sea-level changes are critical in controlling initiation, growth, drowning or sub-aerial exposure, subsequent re-initiation, and final drowning. However, over longer timescales (> 100-500??ka) continued tectonic subsidence and basement substrate morphology influence broad scale reef morphology and backstepping geometries. Drilling of these reefs will yield greatly expanded stratigraphic sections compared with similar reefs on slowly subsiding, stable and uplifting margins, and thus they represent a unique archive of sea-level and climate

  11. Partial mortality in massive reef corals as an indicator of sediment stress on coral reefs

    International Nuclear Information System (INIS)

    Partial mortality and fission on colonies of four common massive coral species were examined at sites differing in their exposure to river sediments in St. Lucia, West Indies. Rates of partial mortality were higher close to the river mouths, where more sediments were deposited, than away from the rivers in two coral species. Frequency of fission showed no significant trend. The percent change in coral cover on reefs from 1995 to 1998 was negatively related to the rate of partial mortality estimated in 1998 in all species. This suggests that partial mortality rates could reflect longer-term temporal changes in coral communities. Similar conclusions could also be reached using a less precise measure and simply recording partial mortality on colonies as <50% and ≥50% dead tissue. We conclude that partial mortality in some species of massive reef corals, expressed as the amount of dead tissue per colony, could provide a rapid and effective means of detecting sediment stress on coral reefs

  12. Evidence of extensive reef development and high coral cover in nearshore environments: implications for understanding coral adaptation in turbid settings

    Science.gov (United States)

    Morgan, Kyle M.; Perry, Chris T.; Smithers, Scott G.; Johnson, Jamie A.; Daniell, James J.

    2016-07-01

    Mean coral cover has reportedly declined by over 15% during the last 30 years across the central Great Barrier Reef (GBR). Here, we present new data that documents widespread reef development within the more poorly studied turbid nearshore areas (coral cover on these reefs averages 38% (twice that reported on mid- and outer-shelf reefs). Of the surveyed seafloor area, 11% had distinct reef or coral community cover. Although the survey area represents a small subset of the nearshore zone (15.5 km2), this reef density is comparable to that measured across the wider GBR shelf (9%). We also show that cross-shelf coral cover declines with distance from the coast (R2 = 0.596). Identified coral taxa (21 genera) exhibited clear depth-stratification, corresponding closely to light attenuation and seafloor topography, with reefal development restricted to submarine antecedent bedforms. Data from this first assessment of nearshore reef occurrence and ecology measured across meaningful spatial scales suggests that these coral communities may exhibit an unexpected capacity to tolerate documented declines in water quality. Indeed, these shallow-water nearshore reefs may share many characteristics with their deep-water (>30 m) mesophotic equivalents and may have similar potential as refugia from large-scale disturbances.

  13. Fungi and their role in corals and coral reef ecosystems.

    Science.gov (United States)

    Raghukumar, Chandralata; Ravindran, J

    2012-01-01

    Fungi in coral reefs exist as endoliths, endobionts, saprotrophs and as pathogens. Although algal and fungal endoliths in corals were described way back in 1973, their role in microboring, carbonate alteration, discoloration, density banding, symbiotic or parasitic association was postulated almost 25 years later. Fungi, as pathogens in corals, have become a much discussed topic in the last 10 years. It is either due to the availability of better tools for investigations or greater awareness among the research communities. Fungi which are exclusive as endoliths (endemic) in corals or ubiquitous forms seem to play a role in coral reef system. Fungi associated with sponges and their role in production or induction of secondary metabolites in their host is of primary interest to various pharmaceutical industries and funding agencies. Fungal enzymes in degradation of coral mucus, and plant detritus hold great promise in biotechnological applications. Unravelling fungal diversity in corals and associated reef organisms using culture and culture-independent approaches is a subject gaining attention from research community world over. PMID:22222828

  14. Coral larvae move toward reef sounds.

    Directory of Open Access Journals (Sweden)

    Mark J A Vermeij

    Full Text Available Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm that influence settlement success are difficult to observe in situ and are therefore largely unknown. Here, we show that coral larvae respond to acoustic cues that may facilitate detection of habitat from large distances and from upcurrent of preferred settlement locations. Using in situ choice chambers, we found that settling coral larvae were attracted to reef sounds, produced mainly by fish and crustaceans, which we broadcast underwater using loudspeakers. Our discovery that coral larvae can detect and respond to sound is the first description of an auditory response in the invertebrate phylum Cnidaria, which includes jellyfish, anemones, and hydroids as well as corals. If, like settlement-stage reef fish and crustaceans, coral larvae use reef noise as a cue for orientation, the alleviation of noise pollution in the marine environment may gain further urgency.

  15. Historical change in coral reef communities in Caribbean Panama

    OpenAIRE

    Cramer, Katie Lynn

    2011-01-01

    Scientists have witnessed a profound transformation in Caribbean coral reefs since the 1980s that includes a widespread mortality of corals and a shift in coral species composition. These changes have been widely attributed to modern disturbances such as coral disease and coral bleaching that have become prevalent in the most recent decades. However, the demise of corals in the Caribbean represents the most recent chapter in a long history of human alteration of Caribbean reef ecosystems. Cen...

  16. Estimating the Exposure of Coral Reefs and Seagrass Meadows to Land-Sourced Contaminants in River Flood Plumes of the Great Barrier Reef: Validating a Simple Satellite Risk Framework with Environmental Data

    Directory of Open Access Journals (Sweden)

    Caroline Petus

    2016-03-01

    Full Text Available River runoff and associated flood plumes (hereafter river plumes are a major source of land-sourced contaminants to the marine environment, and are a significant threat to coastal and marine ecosystems worldwide. Remote sensing monitoring products have been developed to map the spatial extent, composition and frequency of occurrence of river plumes in the Great Barrier Reef (GBR, Australia. There is, however, a need to incorporate these monitoring products into Risk Assessment Frameworks as management decision tools. A simple Satellite Risk Framework has been recently proposed to generate maps of potential risk to seagrass and coral reef ecosystems in the GBR focusing on the Austral tropical wet season. This framework was based on a “magnitude × likelihood” risk management approach and GBR plume water types mapped from satellite imagery. The GBR plume water types (so called “Primary” for the inshore plume waters, “Secondary” for the midshelf-plume waters and “Tertiary” for the offshore plume waters represent distinct concentrations and combinations of land-sourced and marine contaminants. The current study aimed to test and refine the methods of the Satellite Risk Framework. It compared predicted pollutant concentrations in plume water types (multi-annual average from 2005–2014 to published ecological thresholds, and combined this information with similarly long-term measures of seagrass and coral ecosystem health. The Satellite Risk Framework and newly-introduced multi-annual risk scores were successful in demonstrating where water conditions were, on average, correlated to adverse biological responses. Seagrass meadow abundance (multi-annual change in % cover was negatively correlated to the multi-annual risk score at the site level (R2 = 0.47, p < 0.05. Relationships between multi-annual risk scores and multi-annual changes in proportional macroalgae cover (as an index for coral reef health were more complex (R2 = 0.04, p

  17. Movement patterns of silvertip sharks ( Carcharhinus albimarginatus) on coral reefs

    Science.gov (United States)

    Espinoza, Mario; Heupel, Michelle. R.; Tobin, Andrew J.; Simpfendorfer, Colin A.

    2015-09-01

    Understanding how sharks use coral reefs is essential for assessing risk of exposure to fisheries, habitat loss, and climate change. Despite a wide Indo-Pacific distribution, little is known about the spatial ecology of silvertip sharks ( Carcharhinus albimarginatus), compromising the ability to effectively manage their populations. We examined the residency and movements of silvertip sharks in the central Great Barrier Reef (GBR). An array of 56 VR2W acoustic receivers was used to monitor shark movements on 17 semi-isolated reefs. Twenty-seven individuals tagged with acoustic transmitters were monitored from 70 to 731 d. Residency index to the study site ranged from 0.05 to 0.97, with a mean residency (±SD) of 0.57 ± 0.26, but most individuals were detected at or near their tagging reef. Clear seasonal patterns were apparent, with fewer individuals detected between September and February. A large proportion of the tagged population (>71 %) moved regularly between reefs. Silvertip sharks were detected less during daytime and exhibited a strong diel pattern in depth use, which may be a strategy for optimizing energetic budgets and foraging opportunities. This study provides the first detailed examination of the spatial ecology and behavior of silvertip sharks on coral reefs. Silvertip sharks remained resident at coral reef habitats over long periods, but our results also suggest this species may have more complex movement patterns and use larger areas of the GBR than common reef shark species. Our findings highlight the need to further understand the movement ecology of silvertip sharks at different spatial and temporal scales, which is critical for developing effective management approaches.

  18. Presence of Symbiodinium spp. in macroalgal microhabitats from the southern Great Barrier Reef

    Science.gov (United States)

    Venera-Ponton, D. E.; Diaz-Pulido, G.; Rodriguez-Lanetty, M.; Hoegh-Guldberg, O.

    2010-12-01

    Coral reefs are highly dependent on the mutualistic symbiosis between reef-building corals and dinoflagellates from the genus Symbiodinium. These dinoflagellates spend part of their life cycle outside the coral host and in the majority of the cases have to re-infect corals each generation. While considerable insight has been gained about Symbiodinium in corals, little is known about the ecology and biology of Symbiodinium in other reef microhabitats. This study documents Symbiodinium associating with benthic macroalgae on the southern Great Barrier Reef, including some Symbiodinium that are genetically close to the symbiotic strains from reef-building corals. It is possible that some of these Symbiodinium were in hospite, associated to soritid foraminifera or ciliates; nevertheless, the presence of Symbiodinium C3 and C15 in macroalgal microhabitats may also suggest a potential link between communities of Symbiodinium associating with both coral hosts and macroalgae.

  19. NOAA's Coral Reef Conservation Program: Coral Reef Habitat Mapping Projects in 2016

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Maps are a critical cornerstone of coral reef management, research and planning, with direct links to management needs in a number of forms. To accurately...

  20. Octocoral Species Assembly and Coexistence in Caribbean Coral Reefs.

    Directory of Open Access Journals (Sweden)

    Johanna Velásquez

    Full Text Available What are the determinant factors of community assemblies in the most diverse ecosystem in the ocean? Coral reefs can be divided in continental (i.e., reefs that develop on the continental shelf, including siliciclastic reefs and oceanic (i.e., far off the continental shelf, usually on volcanic substratum; whether or not these habitat differences impose community-wide ecological divergence or species exclusion/coexistence with evolutionary consequences, is unknown.Studying Caribbean octocorals as model system, we determined the phylogenetic community structure in a coral reef community, making emphasis on species coexistence evidenced on trait evolution and environmental feedbacks. Forty-nine species represented in five families constituted the species pool from which a phylogenetic tree was reconstructed using mtDNA. We included data from 11 localities in the Western Caribbean (Colombia including most reef types. To test diversity-environment and phenotype-environment relationships, phylogenetic community structure and trait evolution we carried out comparative analyses implementing ecological and evolutionary approaches.Phylogenetic inferences suggest clustering of oceanic reefs (e.g., atolls contrasting with phylogenetic overdispersion of continental reefs (e.g., reefs banks. Additionally, atolls and barrier reefs had the highest species diversity (Shannon index whereas phylogenetic diversity was higher in reef banks. The discriminant component analysis supported this differentiation between oceanic and continental reefs, where continental octocoral species tend to have greater calyx apertures, thicker branches, prominent calyces and azooxanthellate species. This analysis also indicated a clear separation between the slope and the remaining habitats, caused by the presence or absence of Symbiodinium. K statistic analysis showed that this trait is conserved as well as the branch shape.There was strong octocoral community structure with opposite

  1. Barrier and Platform Reefs of the Vietnamese Coast of the South China Sea

    Directory of Open Access Journals (Sweden)

    Yuri Yakovlevich Latypov

    2013-01-01

    Full Text Available The composition and spatial distribution of the coral communities of the barrier reefs of Giang Bo, Ly Son island and the platform reef at Bach Long Vi Island were described in detail for the first time for Vietnamese waters. In common, more 260 species of corals and their accompanying species of macrobenthos were found. Acroporids, poritids, and mussids among the scleractinian corals dominated. Monospecific aggregations of Alcyonarian Sinularia and Lobophytum and the hydroid Millepora were rather numerous. Based on its geomorphological characteristics, coral species diversity and zonal distribution, the reefs of entire area are comparable with ribbon and platform reefs on the Great Barrier Reef in Australia and to the barrier reefs of the Philippines and Indian Ocean.

  2. Global warming and coral reefs

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    also affect coral planulae dispersion and settle ment. Sexual reproduction' in corals is accompanied by the liberation of planulae which pass through a planktonic phase before settling on a hard substratum. UsuaUy the planktonic phase is short...

  3. Coral Reefs: An English Compilation of Activities for Middle School Students.

    Science.gov (United States)

    Walker, Sharon H.; Newton, R. Amanda; Ortiz, Alida

    This activity book on coral reefs for middle school students is divided into 10 sections. Section 1 contains the introduction. Section 2 describes what coral reefs are while section 3 describes how coral reefs reproduce and grow. Section 4 discusses where coral reefs are found and section 5 describes life on a coral reef. Section 6 discusses the…

  4. Reefs for the future: Resilience of coral reefs in the main Hawaiian Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Declining health of coral reef ecosystems led scientists to search for factors that support reef resilience: the ability of reefs to resist and recover from...

  5. The Global Coral Reef Crisis: Trends and Solutions (Coral Reefs: Values, Threats, and the Marine Aquarium Trade)

    Energy Technology Data Exchange (ETDEWEB)

    Shuman, Craig S. (Reef Check, UCLA)

    2003-02-05

    Second only to tropical rainforests, coral reefs support one of the world's most diverse natural habitats. Over 350 million individuals depend on coral reef resources for food and income. Unfortunately, the Earth is in the midst of a coral reef crisis. Anthropogenic impacts including overfishing, destructive fishing practices, sedimentation and pollution, as well as global climate change, have served to disrupt the natural processes that maintain the health of these ecosystems. Until recently, however, the global extent of the coral reef crisis was unknown. Reef Check was developed in 1996 as a volunteer, community-based monitoring protocol designed to measure the health of coral reefs on a global scale. With goals of education, monitoring, and management, Reef Check has activities in over 60 countries and territories. They have not only provided scientific evidence of the global extent of the coral reef crisis, but have provided the first community based steps to alleviate this urgent situation.

  6. A Global Estimate of the Number of Coral Reef Fishers.

    Directory of Open Access Journals (Sweden)

    Louise S L Teh

    Full Text Available Overfishing threatens coral reefs worldwide, yet there is no reliable estimate on the number of reef fishers globally. We address this data gap by quantifying the number of reef fishers on a global scale, using two approaches - the first estimates reef fishers as a proportion of the total number of marine fishers in a country, based on the ratio of reef-related to total marine fish landed values. The second estimates reef fishers as a function of coral reef area, rural coastal population, and fishing pressure. In total, we find that there are 6 million reef fishers in 99 reef countries and territories worldwide, of which at least 25% are reef gleaners. Our estimates are an improvement over most existing fisher population statistics, which tend to omit accounting for gleaners and reef fishers. Our results suggest that slightly over a quarter of the world's small-scale fishers fish on coral reefs, and half of all coral reef fishers are in Southeast Asia. Coral reefs evidently support the socio-economic well-being of numerous coastal communities. By quantifying the number of people who are employed as reef fishers, we provide decision-makers with an important input into planning for sustainable coral reef fisheries at the appropriate scale.

  7. Changes in Biodiversity and Functioning of Reef Fish Assemblages following Coral Bleaching and Coral Loss

    OpenAIRE

    Graham, Nicholas A. J.; Vanessa Messmer; Pratchett, Morgan S; Andrew S. Hoey; Wilson, Shaun K.

    2011-01-01

    Coral reef ecosystems are increasingly subject to severe, large-scale disturbances caused by climate change (e.g., coral bleaching) and other more direct anthropogenic impacts. Many of these disturbances cause coral loss and corresponding changes in habitat structure, which has further important effects on abundance and diversity of coral reef fishes. Declines in the abundance and diversity of coral reef fishes are of considerable concern, given the potential loss of ecosystem function. This ...

  8. Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems

    NARCIS (Netherlands)

    Rix, L.; de Goeij, J.M.; Mueller, C.E.; Struck, U.; Middelburg, J.J.; van Duyl, F.C.; Al-Horani, F.A.; Wild, C.; Naumann, M.S.; Van Oevelen, D.

    2016-01-01

    Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrient

  9. Fishing down nutrients on coral reefs.

    Science.gov (United States)

    Allgeier, Jacob E; Valdivia, Abel; Cox, Courtney; Layman, Craig A

    2016-01-01

    Fishing is widely considered a leading cause of biodiversity loss in marine environments, but the potential effect on ecosystem processes, such as nutrient fluxes, is less explored. Here, we test how fishing on Caribbean coral reefs influences biodiversity and ecosystem functions provided by the fish community, that is, fish-mediated nutrient capacity. Specifically, we modelled five processes of nutrient storage (in biomass) and supply (via excretion) of nutrients, as well as a measure of their multifunctionality, onto 143 species of coral reef fishes across 110 coral reef fish communities. These communities span a gradient from extreme fishing pressure to protected areas with little to no fishing. We find that in fished sites fish-mediated nutrient capacity is reduced almost 50%, despite no substantial changes in the number of species. Instead, changes in community size and trophic structure were the primary cause of shifts in ecosystem function. These findings suggest that a broader perspective that incorporates predictable impacts of fishing pressure on ecosystem function is imperative for effective coral reef conservation and management. PMID:27529748

  10. Linking Wave Forcing to Coral Cover and Structural Complexity Across Coral Reef Flats

    Science.gov (United States)

    Harris, D. L.; Rovere, A.; Parravicini, V.; Casella, E.

    2015-12-01

    The hydrodynamic regime is a significant component in the geomorphic and ecological development of coral reefs. The energy gradients and flow conditions generated by the breaking and transformation of waves across coral reef crests and flats drive changes in geomorphic structure, and coral growth form and distribution. One of the key aspects in regulating the wave energy propagating across reef flats is the rugosity or roughness of the benthic substrate. Rugosity and structural complexity of coral reefs is also a key indicator of species diversity, ecological functioning, and reef health. However, the links between reef rugosity, coral species distribution and abundance, and hydrodynamic forcing are poorly understood. In this study we examine this relationship by using high resolution measurement of waves in the surf zone and coral reef benthic structure.Pressure transducers (logging at 4 Hz) were deployed in cross reef transects at two sites (Tiahura and Ha'apiti reef systems) in Moorea, French Polynesia with wave characteristics determined on a wave by wave basis. A one dimensional hydrodynamic model (XBeach) was calibrated from this data to determine wave processes on the reef flats under average conditions. Transects of the reef benthic structure were conducted using photographic analysis and the three dimensional reef surface was constructed using structure from motion procedures. From this analysis reef rugosity, changes in coral genus and growth form, and across reef shifts in benthic community were determined. The results show clear changes in benthic assemblages along wave energy gradients with some indication of threshold values of wave induced bed shear stress above which live coral cover was reduced. Reef rugosity was shown to be significantly along the cross-reef transect which has important implications for accurate assessment of wave dissipation across coral reef flats. Links between reef rugosity and coral genus were also observed and may indicate

  11. 75 FR 21650 - Coral Reef Restoration Plan, Draft Programmatic Environmental Impact Statement, Biscayne National...

    Science.gov (United States)

    2010-04-26

    ... National Park Service Coral Reef Restoration Plan, Draft Programmatic Environmental Impact Statement... Availability of the Draft Programmatic Environmental Impact Statement for the Coral Reef Restoration Plan... Environmental Impact Statement (DEIS) for the Coral Reef Restoration Plan for Biscayne National Park,...

  12. Influence of Coral Bleaching on the Fauna of Tutia Reef, Tanzania

    OpenAIRE

    Öhman, M.C.; Lindahl, U.; Schelten, C.K.

    1999-01-01

    In 1998, coral reefs of Tanzania were severely affected by bleaching. The coral mortality that followed caused a concern for coral reef degradation and overall resource depletion. In this study, we investigated coral bleaching effects on the coral reef fauna at Tutia Reef in Mafia Island Marine Park, Tanzania. Corals from adjacent reef patches of the species Acropora formosa were transplanted into plots, and reef structure and associated fish assemblages were examined before and after the ble...

  13. Climate-driven coral reorganisation influences aggressive behaviour in juvenile coral-reef fishes

    Science.gov (United States)

    Kok, Judith E.; Graham, Nicholas A. J.; Hoogenboom, Mia O.

    2016-06-01

    Globally, habitat degradation is altering the abundance and diversity of species in a variety of ecosystems. This study aimed to determine how habitat degradation, in terms of changing coral composition under climate change, affected abundance, species richness and aggressive behaviour of juveniles of three damselfishes ( Pomacentrus moluccensis, P. amboinensis and Dischistodus perspicillatus, in order of decreasing reliance on coral). Patch reefs were constructed to simulate two types of reefs: present-day reefs that are vulnerable to climate-induced coral bleaching, and reefs with more bleaching-robust coral taxa, thereby simulating the likely future of coral reefs under a warming climate. Fish communities were allowed to establish naturally on the reefs during the summer recruitment period. Climate-robust reefs had lower total species richness of coral-reef fishes than climate-vulnerable reefs, but total fish abundance was not significantly different between reef types (pooled across all species and life-history stages). The nature of aggressive interactions, measured as the number of aggressive chases, varied according to coral composition; on climate-robust reefs, juveniles used the substratum less often to avoid aggression from competitors, and interspecific aggression became relatively more frequent than intraspecific aggression for juveniles of the coral-obligate P. moluccensis. This study highlights the importance of coral composition as a determinant of behaviour and diversity of coral-reef fishes.

  14. Reassessing the trophic role of reef sharks as apex predators on coral reefs

    Science.gov (United States)

    Frisch, Ashley J.; Ireland, Matthew; Rizzari, Justin R.; Lönnstedt, Oona M.; Magnenat, Katalin A.; Mirbach, Christopher E.; Hobbs, Jean-Paul A.

    2016-06-01

    Apex predators often have strong top-down effects on ecosystem components and are therefore a priority for conservation and management. Due to their large size and conspicuous predatory behaviour, reef sharks are typically assumed to be apex predators, but their functional role is yet to be confirmed. In this study, we used stomach contents and stable isotopes to estimate diet, trophic position and carbon sources for three common species of reef shark ( Triaenodon obesus, Carcharhinus melanopterus and C. amblyrhynchos) from the Great Barrier Reef (Australia) and evaluated their assumed functional role as apex predators by qualitative and quantitative comparisons with other sharks and large predatory fishes. We found that reef sharks do not occupy the apex of coral reef food chains, but instead have functional roles similar to those of large predatory fishes such as snappers, emperors and groupers, which are typically regarded as high-level mesopredators. We hypothesise that a degree of functional redundancy exists within this guild of predators, potentially explaining why shark-induced trophic cascades are rare or subtle in coral reef ecosystems. We also found that reef sharks participate in multiple food webs (pelagic and benthic) and are sustained by multiple sources of primary production. We conclude that large conspicuous predators, be they elasmobranchs or any other taxon, should not axiomatically be regarded as apex predators without thorough analysis of their diet. In the case of reef sharks, our dietary analyses suggest they should be reassigned to an alternative trophic group such as high-level mesopredators. This change will facilitate improved understanding of how reef communities function and how removal of predators (e.g., via fishing) might affect ecosystem properties.

  15. Vertical variations of coral reef drag forces

    Science.gov (United States)

    Asher, Shai; Niewerth, Stephan; Koll, Katinka; Shavit, Uri

    2016-05-01

    Modeling flow in a coral reef requires a closure model that links the local drag force to the local mean velocity. However, the spatial flow variations make it difficult to predict the distribution of the local drag. Here we report on vertical profiles of measured drag and velocity in a laboratory reef that was made of 81 Pocillopora Meandrina colony skeletons, densely arranged along a tilted flume. Two corals were CT-scanned, sliced horizontally, and printed using a 3-D printer. Drag was measured as a function of height above the bottom by connecting the slices to drag sensors. Profiles of velocity were measured in-between the coral branches and above the reef. Measured drag of whole colonies shows an excellent agreement with previous field and laboratory studies; however, these studies never showed how drag varies vertically. The vertical distribution of drag is reported as a function of flow rate and water level. When the water level is the same as the reef height, Reynolds stresses are negligible and the drag force per unit fluid mass is nearly constant. However, when the water depth is larger, Reynolds stress gradients become significant and drag increases with height. An excellent agreement was found between the drag calculated by a momentum budget and the measured drag of the individual printed slices. Finally, we propose a modified formulation of the drag coefficient that includes the normal dispersive stress term and results in reduced variations of the drag coefficient at the cost of introducing an additional coefficient.

  16. A Global Estimate of the Number of Coral Reef Fishers

    OpenAIRE

    Teh, Louise S. L.; Lydia C. L. Teh; Sumaila, U. Rashid

    2013-01-01

    Overfishing threatens coral reefs worldwide, yet there is no reliable estimate on the number of reef fishers globally. We address this data gap by quantifying the number of reef fishers on a global scale, using two approaches - the first estimates reef fishers as a proportion of the total number of marine fishers in a country, based on the ratio of reef-related to total marine fish landed values. The second estimates reef fishers as a function of coral reef area, rural coastal population, and...

  17. Carrying capacity of coral reefs

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    The sustainable yield of a commercially exploited fishery is assessed by the biological and environmental factors (including fishing effort). These parameters with a reef are vastly diverse-size, location, species diversity, productivity type...

  18. Are coral reefs victims of their own past success?

    OpenAIRE

    Renema, Willem; Pandolfi, John M.; Kiessling, Wolfgang; Bosellini, Francesca R.; Klaus, James S.; Korpanty, Chelsea; Rosen, Brian R.; Santodomingo, Nadiezhda; Wallace, Carden C; Webster, Jody M.; Johnson, Kenneth G.

    2016-01-01

    As one of the most prolific and widespread reef builders, the staghorn coral Acropora holds a disproportionately large role in how coral reefs will respond to accelerating anthropogenic change. We show that although Acropora has a diverse history extended over the past 50 million years, it was not a dominant reef builder until the onset of high-amplitude glacioeustatic sea-level fluctuations 1.8 million years ago. High growth rates and propagation by fragmentation have favored staghorn corals...

  19. The Decline of Coral Reefs: a Political Economy Approach

    OpenAIRE

    Samuel, Asumadu-Sarkodie

    2015-01-01

    Coral reefs provide economic services like job, food and tourism. Yet, within the past decades, there has been an overwhelming decline in the vitality of coral reefs and their ecosystem. Scientist have not be able to set the record straight regarding their scientific argument on biodiversity and ecological wealth of natural environment. Therefore, actions to recover coral reefs from destruction have proved futile. This paper will analyze the economical values, economic valuation, socioeconomi...

  20. Hysteresis in coral reefs under macroalgal toxicity and overfishing

    OpenAIRE

    Bhattacharyya, Joydeb; Pal, Samares

    2015-01-01

    Macroalgae and corals compete for the available space in coral reef ecosystems.While herbivorous reef fish play a beneficial role in decreasing the growth of macroalgae, macroalgal toxicity and overfishing of herbivores leads to proliferation of macroalgae. The abundance of macroalgae changes the community structure towards a macroalgae-dominated reef ecosystem. We investigate coral-macroalgal phase shifts by means of a continuous time model in a food chain. Conditions for local asymptotic st...

  1. Evolution of Coral Rubble Deposits on a Reef Platform as Detected by Remote Sensing

    Directory of Open Access Journals (Sweden)

    Ana Vila-Concejo

    2012-12-01

    Full Text Available An investigation into the evolution of coral rubble deposits on a coral reef platform is assessed using high-resolution remote sensing data and geospatial analysis. Digital change detection analysis techniques are applied to One Tree Reef in the southern Great Barrier Reef by analysing aerial photographs and satellite images captured between 1964 and 2009. Two main types of rubble deposits were identified: (1 rubble flats that are featureless mass accumulations of coral rubble; and, (2 rubble spits that are shore-normal linear features. While both deposits prograde in a lagoon-ward direction, rubble spits move faster (~2 m/yr than rubble flats (~0.5 m/yr. The volume of rubble, the underlying substrate, the energy regime, and storm frequency control the rate of progradation. Rubble flat occurrence is restricted to the high-energy (windward margin of the coral reef platform, while rubble spits are distributed reef wide, both in modal high energy and modal low energy regions of the reef. Rubble spit deposition is considered to be a result of enlarged spur and groove morphology of the forereef, whereby wave energy is focused through the enlarged groove formations causing the preferential deposition of coral rubble in particular zones of the adjacent reef flat. One last control is thought to be the elevation of the reef crest whereby lower areas are more prone to rubble flat development. A vertical and ocean-ward accumulation of rubble is occurring on the windward margin of the reef leading to a build-up and build-out of the reef, governing the expansion of the reef footprint. This study shows for the first time the evolution of a coral reef rubble flat and rubble spits over decadal time scales as detected through remotely sensed images spanning 45 years.

  2. Exploring the hidden shallows: extensive reef development and resilience within the turbid nearshore Great Barrier Reef

    Science.gov (United States)

    Morgan, Kyle; Perry, Chris; Smithers, Scott; Johnson, Jamie; Daniell, James

    2016-04-01

    Mean coral cover on Australia's Great Barrier Reef (GBR) has reportedly declined by over 15% during the last 30 years. Climate change events and outbreaks of coral disease have been major drivers of degradation, often exacerbating the stresses caused by localised human activities (e.g. elevated sediment and nutrient inputs). Here, however, in the first assessment of nearshore reef occurrence and ecology across meaningful spatial scales (15.5 sq km), we show that areas of the GBR shelf have exhibited strong intra-regional variability in coral resilience to declining water quality. Specifically, within the highly-turbid "mesophotic" nearshore (scale disturbance as their deep-water (>30 m) "mesophotic" equivalents, and also provide a basis from which to model future trajectories of reef growth within nearshore areas.

  3. Exploring the hidden shallows: extensive reef development and resilience within the turbid nearshore Great Barrier Reef

    Science.gov (United States)

    Morgan, Kyle; Perry, Chris; Smithers, Scott; Johnson, Jamie; Daniell, James

    2016-04-01

    Mean coral cover on Australia's Great Barrier Reef (GBR) has reportedly declined by over 15% during the last 30 years. Climate change events and outbreaks of coral disease have been major drivers of degradation, often exacerbating the stresses caused by localised human activities (e.g. elevated sediment and nutrient inputs). Here, however, in the first assessment of nearshore reef occurrence and ecology across meaningful spatial scales (15.5 sq km), we show that areas of the GBR shelf have exhibited strong intra-regional variability in coral resilience to declining water quality. Specifically, within the highly-turbid "mesophotic" nearshore (30 m) "mesophotic" equivalents, and also provide a basis from which to model future trajectories of reef growth within nearshore areas.

  4. A comparison of coral reef survey methods

    OpenAIRE

    Weinberg, Steven

    1981-01-01

    Seven coral reef survey methods were compared in an experimental plot of 100 m² on a Caribbean shelf reef off southwest Puerto Rico. This area was mapped in detail by means of underwater photography and in situ drawings, in order to provide an objective standard against which to test the results obtained by the different survey methods. Minimal survey area was determined, and minimal sampling time deduced for one of the most laborious methods. Two 45-minute periods (i.e. 1.6 X minimal time) w...

  5. The status of coral reef ecology research in the Red Sea

    Science.gov (United States)

    Berumen, M. L.; Hoey, A. S.; Bass, W. H.; Bouwmeester, J.; Catania, D.; Cochran, J. E. M.; Khalil, M. T.; Miyake, S.; Mughal, M. R.; Spaet, J. L. Y.; Saenz-Agudelo, P.

    2013-09-01

    The Red Sea has long been recognized as a region of high biodiversity and endemism. Despite this diversity and early history of scientific work, our understanding of the ecology of coral reefs in the Red Sea has lagged behind that of other large coral reef systems. We carried out a quantitative assessment of ISI-listed research published from the Red Sea in eight specific topics (apex predators, connectivity, coral bleaching, coral reproductive biology, herbivory, marine protected areas, non-coral invertebrates and reef-associated bacteria) and compared the amount of research conducted in the Red Sea to that from Australia's Great Barrier Reef (GBR) and the Caribbean. On average, for these eight topics, the Red Sea had 1/6th the amount of research compared to the GBR and about 1/8th the amount of the Caribbean. Further, more than 50 % of the published research from the Red Sea originated from the Gulf of Aqaba, a small area (coral reef regions, the Red Sea may yet have a significant role to play in our understanding of coral reef ecology at a global scale.

  6. 75 FR 39917 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs off the...

    Science.gov (United States)

    2010-07-13

    ... Coral Reef Research Foundation (CRRF, http://www.coralreefresearchfoundation.org/ ). Samples would be..., and South Atlantic; Coral and Coral Reefs off the Southern Atlantic States; Exempted Fishing Permit... for Coral, Coral Reefs, and Live/Hardbottom Habitat of the South Atlantic Region. The applicant...

  7. 76 FR 30110 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the...

    Science.gov (United States)

    2011-05-24

    ... Cancer Institute ( http://www.cancer.gov/ ) and the Coral Reef Research Foundation (CRRF, http://www..., and South Atlantic; Coral and Coral Reefs Off the Southern Atlantic States; Exempted Fishing Permit... implementing the Fishery Management Plan for Coral, Coral Reefs, and Live/Hardbottom Habitat of the...

  8. Human Dimensions of Coral Reef Social-Ecological Systems

    OpenAIRE

    John N. Kittinger; Elena M. Finkbeiner; Edward W. Glazier; Larry B Crowder

    2012-01-01

    Coral reefs are among the most diverse ecosystems on the planet but are declining because of human activities. Despite general recognition of the human role in the plight of coral reefs, the vast majority of research focuses on the ecological rather than the human dimensions of reef ecosystems, limiting our understanding of social relationships with these environments as well as potential solutions for reef recovery. General frameworks for social-ecological systems (SESs) have been advanced, ...

  9. Water Column Correction for Coral Reef Studies by Remote Sensing

    OpenAIRE

    Maria Laura Zoffoli; Robert Frouin; Milton Kampel

    2014-01-01

    Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilit...

  10. The Microbial Signature Provides Insight into the Mechanistic Basis of Coral Success across Reef Habitats

    Science.gov (United States)

    Leggat, William; Bongaerts, Pim

    2016-01-01

    ABSTRACT For ecosystems vulnerable to environmental change, understanding the spatiotemporal stability of functionally crucial symbioses is fundamental to determining the mechanisms by which these ecosystems may persist. The coral Pachyseris speciosa is a successful environmental generalist that succeeds in diverse reef habitats. The generalist nature of this coral suggests it may have the capacity to form functionally significant microbial partnerships to facilitate access to a range of nutritional sources within different habitats. Here, we propose that coral is a metaorganism hosting three functionally distinct microbial interactions: a ubiquitous core microbiome of very few symbiotic host-selected bacteria, a microbiome of spatially and/or regionally explicit core microbes filling functional niches (100,000 phylotypes). We find that this coral hosts upwards of 170,000 distinct phylotypes and provide evidence for the persistence of a select group of bacteria in corals across environmental habitats of the Great Barrier Reef and Coral Sea. We further show that a higher number of bacteria are consistently associated with corals on mesophotic reefs than on shallow reefs. An increase in microbial diversity with depth suggests reliance by this coral on bacteria for nutrient acquisition on reefs exposed to nutrient upwelling. Understanding the complex microbial communities of host organisms across broad biotic and abiotic environments as functionally distinct microbiomes can provide insight into those interactions that are ubiquitous niche symbioses and those that provide competitive advantage within the hosts’ environment. PMID:27460792

  11. Climate Change, Human Impacts, and the Resilience of Coral Reefs

    Science.gov (United States)

    Hughes, T. P.; Baird, A. H.; Bellwood, D. R.; Card, M.; Connolly, S. R.; Folke, C.; Grosberg, R.; Hoegh-Guldberg, O.; Jackson, J. B. C.; Kleypas, J.; Lough, J. M.; Marshall, P.; Nyström, M.; Palumbi, S. R.; Pandolfi, J. M.; Rosen, B.; Roughgarden, J.

    2003-08-01

    The diversity, frequency, and scale of human impacts on coral reefs are increasing to the extent that reefs are threatened globally. Projected increases in carbon dioxide and temperature over the next 50 years exceed the conditions under which coral reefs have flourished over the past half-million years. However, reefs will change rather than disappear entirely, with some species already showing far greater tolerance to climate change and coral bleaching than others. International integration of management strategies that support reef resilience need to be vigorously implemented, and complemented by strong policy decisions to reduce the rate of global warming.

  12. Warm-water coral reefs and climate change

    Science.gov (United States)

    Spalding, Mark D.; Brown, Barbara E.

    2015-11-01

    Coral reefs are highly dynamic ecosystems that are regularly exposed to natural perturbations. Human activities have increased the range, intensity, and frequency of disturbance to reefs. Threats such as overfishing and pollution are being compounded by climate change, notably warming and ocean acidification. Elevated temperatures are driving increasingly frequent bleaching events that can lead to the loss of both coral cover and reef structural complexity. There remains considerable variability in the distribution of threats and in the ability of reefs to survive or recover from such disturbances. Without significant emissions reductions, however, the future of coral reefs is increasingly bleak.

  13. Reef-Scale Thermal Stress Monitoring of Coral Ecosystems: New 5-km Global Products from NOAA Coral Reef Watch

    OpenAIRE

    Gang Liu; Heron, Scott F.; C. Mark Eakin; Muller-Karger, Frank E.; Maria Vega-Rodriguez; Liane S. Guild; Jacqueline L. De La Cour; Erick F. Geiger; Skirving, William J.; Timothy F. R. Burgess; Alan E. Strong; Andy Harris; Eileen Maturi; Alexander Ignatov; John Sapper

    2014-01-01

    The U.S. National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch (CRW) program has developed a daily global 5-km product suite based on satellite observations to monitor thermal stress on coral reefs. These products fulfill requests from coral reef managers and researchers for higher resolution products by taking advantage of new satellites, sensors and algorithms. Improvements of the 5-km products over CRW’s heritage global 50-km products are derived from: (1) the higher reso...

  14. Vitamin B_<12> compounds in coral reef

    OpenAIRE

    Nishijima, Toshitaka

    1994-01-01

    The distribution of free- and bound-vitamin B_ in the waters of coral reef of Heron Island, Australia was investigated. The contents of total and free-vitamin B_ were fairly high: 3.2-23.8 ng/l and 1.98-22.4 ng/l, respectively. The bound-B_, which is a biologically non-active B_, ranged from O.77 to 2.31 ng/l and amounted to 5.8-47.9 % (mean: 23.5 %) of total B_. The content of free-B_ in the waters of coral reef was found to be close to the critical level which maximizes the growth of B_-req...

  15. Effects of cold stress and heat stress on coral fluorescence in reef-building corals

    OpenAIRE

    Melissa S. Roth; Deheyn, Dimitri D.

    2013-01-01

    Widespread temperature stress has caused catastrophic coral bleaching events that have been devastating for coral reefs. Here, we evaluate whether coral fluorescence could be utilized as a noninvasive assessment for coral health. We conducted cold and heat stress treatments on the branching coral Acropora yongei, and found that green fluorescent protein (GFP) concentration and fluorescence decreased with declining coral health, prior to initiation of bleaching. Ultimately, cold-treated corals...

  16. Building coral reef resilience through assisted evolution

    Science.gov (United States)

    van Oppen, Madeleine J. H.; Oliver, James K.; Putnam, Hollie M.; Gates, Ruth D.

    2015-01-01

    The genetic enhancement of wild animals and plants for characteristics that benefit human populations has been practiced for thousands of years, resulting in impressive improvements in commercially valuable species. Despite these benefits, genetic manipulations are rarely considered for noncommercial purposes, such as conservation and restoration initiatives. Over the last century, humans have driven global climate change through industrialization and the release of increasing amounts of CO2, resulting in shifts in ocean temperature, ocean chemistry, and sea level, as well as increasing frequency of storms, all of which can profoundly impact marine ecosystems. Coral reefs are highly diverse ecosystems that have suffered massive declines in health and abundance as a result of these and other direct anthropogenic disturbances. There is great concern that the high rates, magnitudes, and complexity of environmental change are overwhelming the intrinsic capacity of corals to adapt and survive. Although it is important to address the root causes of changing climate, it is also prudent to explore the potential to augment the capacity of reef organisms to tolerate stress and to facilitate recovery after disturbances. Here, we review the risks and benefits of the improvement of natural and commercial stocks in noncoral reef systems and advocate a series of experiments to determine the feasibility of developing coral stocks with enhanced stress tolerance through the acceleration of naturally occurring processes, an approach known as (human)-assisted evolution, while at the same time initiating a public dialogue on the risks and benefits of this approach. PMID:25646461

  17. The Ecological Role of Sharks on Coral Reefs.

    Science.gov (United States)

    Roff, George; Doropoulos, Christopher; Rogers, Alice; Bozec, Yves-Marie; Krueck, Nils C; Aurellado, Eleanor; Priest, Mark; Birrell, Chico; Mumby, Peter J

    2016-05-01

    Sharks are considered the apex predator of coral reefs, but the consequences of their global depletion are uncertain. Here we explore the ecological roles of sharks on coral reefs and, conversely, the importance of reefs for sharks. We find that most reef-associated shark species do not act as apex predators but instead function as mesopredators along with a diverse group of reef fish. While sharks perform important direct and indirect ecological roles, the evidence to support hypothesised shark-driven trophic cascades that benefit corals is weak and equivocal. Coral reefs provide some functional benefits to sharks, but sharks do not appear to favour healthier reef environments. Restoring populations of sharks is important and can yet deliver ecological surprise. PMID:26975420

  18. The role of turtles as coral reef macroherbivores

    KAUST Repository

    Goatley, Christopher H. R.

    2012-06-29

    Herbivory is widely accepted as a vital function on coral reefs. To date, the majority of studies examining herbivory in coral reef environments have focused on the roles of fishes and/or urchins, with relatively few studies considering the potential role of macroherbivores in reef processes. Here, we introduce evidence that highlights the potential role of marine turtles as herbivores on coral reefs. While conducting experimental habitat manipulations to assess the roles of herbivorous reef fishes we observed green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) showing responses that were remarkably similar to those of herbivorous fishes. Reducing the sediment load of the epilithic algal matrix on a coral reef resulted in a forty-fold increase in grazing by green turtles. Hawksbill turtles were also observed to browse transplanted thalli of the macroalga Sargassum swartzii in a coral reef environment. These responses not only show strong parallels to herbivorous reef fishes, but also highlight that marine turtles actively, and intentionally, remove algae from coral reefs. When considering the size and potential historical abundance of marine turtles we suggest that these potentially valuable herbivores may have been lost from many coral reefs before their true importance was understood. © 2012 Goatley et al.

  19. Are coral reefs victims of their own past success?

    Science.gov (United States)

    Renema, Willem; Pandolfi, John M; Kiessling, Wolfgang; Bosellini, Francesca R; Klaus, James S; Korpanty, Chelsea; Rosen, Brian R; Santodomingo, Nadiezhda; Wallace, Carden C; Webster, Jody M; Johnson, Kenneth G

    2016-04-01

    As one of the most prolific and widespread reef builders, the staghorn coral Acropora holds a disproportionately large role in how coral reefs will respond to accelerating anthropogenic change. We show that although Acropora has a diverse history extended over the past 50 million years, it was not a dominant reef builder until the onset of high-amplitude glacioeustatic sea-level fluctuations 1.8 million years ago. High growth rates and propagation by fragmentation have favored staghorn corals since this time. In contrast, staghorn corals are among the most vulnerable corals to anthropogenic stressors, with marked global loss of abundance worldwide. The continued decline in staghorn coral abundance and the mounting challenges from both local stress and climate change will limit the coral reefs' ability to provide ecosystem services. PMID:27152330

  20. The impacts of tourism on coral reef conservation awareness and support in coastal communities in Belize

    Science.gov (United States)

    Diedrich, A.

    2007-12-01

    Marine recreational tourism is one of a number of threats to the Belize Barrier Reef but, conversely, represents both a motivation and source of resources for its conservation. The growth of tourism in Belize has resulted in the fact that many coastal communities are in varying stages of a socio-economic shift from dependence on fishing to dependence on tourism. In a nation becoming increasingly dependent on the health of its coral reef ecosystems for economic prosperity, a shift from extractive uses to their preservation is both necessary and logical. Through examining local perception data in five coastal communities in Belize, each attracting different levels of coral reef related tourism, this analysis is intended to explore the relationship between tourism development and local coral reef conservation awareness and support. The results of the analysis show a positive correlation between tourism development and coral reef conservation awareness and support in the study communities. The results also show a positive correlation between tourism development and local perceptions of quality of life, a trend that is most likely the source of the observed relationship between tourism and conservation. The study concludes that, because the observed relationship may be dependent on continued benefits from tourism as opposed to a perceived crisis in coral reef health, Belize must pay close attention to tourism impacts in the future. Failure to do this could result in a destructive feedback loop that would contribute to the degradation of the reef and, ultimately, Belize’s diminished competitiveness in the ecotourism market.

  1. Coral Reef and Hardbottom from Unified Florida Reef Tract Map (NODC Accession 0123059)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a subset of the Unified Map representing Coral reef and Hardbottom areas. Version 1.1 - December 2013. The Unified Florida Reef Tract Map (Unified...

  2. The Power of Three: Coral Reefs, Seagrasses and Mangroves Protect Coastal Regions and Increase Their Resilience

    Science.gov (United States)

    Guannel, Greg; Arkema, Katie; Ruggiero, Peter; Verutes, Gregory

    2016-01-01

    Natural habitats have the ability to protect coastal communities against the impacts of waves and storms, yet it is unclear how different habitats complement each other to reduce those impacts. Here, we investigate the individual and combined coastal protection services supplied by live corals on reefs, seagrass meadows, and mangrove forests during both non-storm and storm conditions, and under present and future sea-level conditions. Using idealized profiles of fringing and barrier reefs, we quantify the services supplied by these habitats using various metrics of inundation and erosion. We find that, together, live corals, seagrasses, and mangroves supply more protection services than any individual habitat or any combination of two habitats. Specifically, we find that, while mangroves are the most effective at protecting the coast under non-storm and storm conditions, live corals and seagrasses also moderate the impact of waves and storms, thereby further reducing the vulnerability of coastal regions. Also, in addition to structural differences, the amount of service supplied by habitats in our analysis is highly dependent on the geomorphic setting, habitat location and forcing conditions: live corals in the fringing reef profile supply more protection services than seagrasses; seagrasses in the barrier reef profile supply more protection services than live corals; and seagrasses, in our simulations, can even compensate for the long-term degradation of the barrier reef. Results of this study demonstrate the importance of taking integrated and place-based approaches when quantifying and managing for the coastal protection services supplied by ecosystems. PMID:27409584

  3. The Power of Three: Coral Reefs, Seagrasses and Mangroves Protect Coastal Regions and Increase Their Resilience.

    Science.gov (United States)

    Guannel, Greg; Arkema, Katie; Ruggiero, Peter; Verutes, Gregory

    2016-01-01

    Natural habitats have the ability to protect coastal communities against the impacts of waves and storms, yet it is unclear how different habitats complement each other to reduce those impacts. Here, we investigate the individual and combined coastal protection services supplied by live corals on reefs, seagrass meadows, and mangrove forests during both non-storm and storm conditions, and under present and future sea-level conditions. Using idealized profiles of fringing and barrier reefs, we quantify the services supplied by these habitats using various metrics of inundation and erosion. We find that, together, live corals, seagrasses, and mangroves supply more protection services than any individual habitat or any combination of two habitats. Specifically, we find that, while mangroves are the most effective at protecting the coast under non-storm and storm conditions, live corals and seagrasses also moderate the impact of waves and storms, thereby further reducing the vulnerability of coastal regions. Also, in addition to structural differences, the amount of service supplied by habitats in our analysis is highly dependent on the geomorphic setting, habitat location and forcing conditions: live corals in the fringing reef profile supply more protection services than seagrasses; seagrasses in the barrier reef profile supply more protection services than live corals; and seagrasses, in our simulations, can even compensate for the long-term degradation of the barrier reef. Results of this study demonstrate the importance of taking integrated and place-based approaches when quantifying and managing for the coastal protection services supplied by ecosystems. PMID:27409584

  4. Temporary refugia for coral reefs in a warming world

    Science.gov (United States)

    van Hooidonk, R.; Maynard, J. A.; Planes, S.

    2013-05-01

    Climate-change impacts on coral reefs are expected to include temperature-induced spatially extensive bleaching events. Bleaching causes mortality when temperature stress persists but exposure to bleaching conditions is not expected to be spatially uniform at the regional or global scale. Here we show the first maps of global projections of bleaching conditions based on ensembles of IPCC AR5 (ref. ) models forced with the new Representative Concentration Pathways (RCPs). For the three RCPs with larger CO2 emissions (RCP 4.5, 6.0 and 8.5) the onset of annual bleaching conditions is associated with ~ 510ppm CO2 equivalent; the median year of all locations is 2040 for the fossil-fuel aggressive RCP 8.5. Spatial patterns in the onset of annual bleaching conditions are similar for each of the RCPs. For RCP 8.5, 26% of reef cells are projected to experience annual bleaching conditions more than 5 years later than the median. Some of these temporary refugia include the western Indian Ocean, Thailand, the southern Great Barrier Reef and central French Polynesia. A reduction in the growth of greenhouse-gas emissions corresponding to the difference between RCP 8.5 and 6.0 delays annual bleaching in ~ 23% of reef cells more than two decades, which might conceivably increase the potential for these reefs to cope with these changes.

  5. Coral reefs as eco-factories for fixing CO2

    International Nuclear Information System (INIS)

    This paper presents an estimation of carbon dioxide fixation rate by the natural coral reefs. The author explains mechanism and rate of carbon dioxide fixation; then he presents the fixation by coral reefs on Ishigaki Island. (TEC). 3 refs., 3 figs

  6. Coral reefs in crisis: reversing the biotic death spiral

    OpenAIRE

    Hay, Mark E.; Rasher, Douglas B

    2010-01-01

    Coral reefs are disappearing due to global warming, overfishing, ocean acidification, pollution, and interactions of these and other stresses. Ecologically informed management of fishes that facilitate corals by suppressing seaweeds may be our best bet for bringing reefs back from the brink of extinction.

  7. Symbiont diversity may help coral reefs survive moderate climate change

    OpenAIRE

    Baskett, ML; Gaines, SD; Nisbet, RM

    2009-01-01

    Given climate change, thermal stress-related mass coral-bleaching events present one of the greatest anthropogenic threats to coral reefs. While corals and their symbiotic algae may respond to future temperatures through genetic adaptation and shifts in community compositions, the climate may change too rapidly for coral response. To test this potential for response, here we develop a model of coral and symbiont ecological dynamics and symbiont evolutionary dynamics. Model results without var...

  8. Seaweed allelopathy degrades the resilience and function of coral reefs

    OpenAIRE

    Rasher, Douglas B; Hay, Mark E.

    2010-01-01

    Coral reefs are in dramatic global decline due to a host of local- and global-scale anthropogenic disturbances that suppress corals and enhance seaweeds. This decline is exacerbated, and recovery made less likely, due to over-fishing of herbivores that normally limit seaweed effects on corals. Seaweeds were known to suppress coral reproduction and recruitment, but in a recent study, we demonstrated that numerous seaweeds also directly poison corals via lipid-soluble allelochemicals transferre...

  9. The wicked problem of China's disappearing coral reefs.

    Science.gov (United States)

    Hughes, Terry P; Huang, Hui; Young, Matthew A L

    2013-04-01

    We examined the development of coral reef science and the policies, institutions, and governance frameworks for management of coral reefs in China in order to highlight the wicked problem of preserving reefs while simultaneously promoting human development and nation building. China and other sovereign states in the region are experiencing unprecedented economic expansion, rapid population growth, mass migration, widespread coastal development, and loss of habitat. We analyzed a large, fragmented literature on the condition of coral reefs in China and the disputed territories of the South China Sea. We found that coral abundance has declined by at least 80% over the past 30 years on coastal fringing reefs along the Chinese mainland and adjoining Hainan Island. On offshore atolls and archipelagos claimed by 6 countries in the South China Sea, coral cover has declined from an average of >60% to around 20% within the past 10-15 years. Climate change has affected these reefs far less than coastal development, pollution, overfishing, and destructive fishing practices. Ironically, these widespread declines in the condition of reefs are unfolding as China's research and reef-management capacity are rapidly expanding. Before the loss of corals becomes irreversible, governance of China's coastal reefs could be improved by increasing public awareness of declining ecosystem services, by providing financial support for training of reef scientists and managers, by improving monitoring of coral reef dynamics and condition to better inform policy development, and by enforcing existing regulations that could protect coral reefs. In the South China Sea, changes in policy and legal frameworks, refinement of governance structures, and cooperation among neighboring countries are urgently needed to develop cooperative management of contested offshore reefs. PMID:23140101

  10. Effects of alternate reef states on coral reef fish habitat associations

    OpenAIRE

    Lecchini, David; Carassou, Laure; Frederich, Bruno; Nakamura, Yohei; Mills, Suzanne C.; Galzin, René

    2012-01-01

    The present study describes ontogenetic shifts in habitat use for 15 species of coral reef fish at Rangiroa Atoll, French Polynesia. The distribution of fish in different habitats at three ontogenetic stages (new settler, juvenile, and adult) was investigated in coral- dominated and algal-dominated sites at two reefs (fringing reef and inner reef of motu). Three main ontogenetic patterns in habitat use were identified: (1) species that did not change habitats between new settler and juvenile ...

  11. Benthic buffers and boosters of ocean acidification on coral reefs

    Directory of Open Access Journals (Sweden)

    K. R. N. Anthony

    2013-07-01

    Full Text Available Ocean acidification is a threat to marine ecosystems globally. In shallow-water systems, however, ocean acidification can be masked by benthic carbon fluxes, depending on community composition, seawater residence time, and the magnitude and balance of net community production (NCP and calcification (NCC. Here, we examine how six benthic groups from a coral reef environment on Heron Reef (Great Barrier Reef, Australia contribute to changes in the seawater aragonite saturation state (Ωa. Results of flume studies using intact reef habitats (1.2 m by 0.4 m, showed a hierarchy of responses across groups, depending on CO2 level, time of day and water flow. At low CO2 (350–450 μatm, macroalgae (Chnoospora implexa, turfs and sand elevated Ωa of the flume water by around 0.10 to 1.20 h−1 – normalised to contributions from 1 m2 of benthos to a 1 m deep water column. The rate of Ωa increase in these groups was doubled under acidification (560–700 μatm and high flow (35 compared to 8 cm s−1. In contrast, branching corals (Acropora aspera increased Ωa by 0.25 h−1 at ambient CO2 (350–450 μatm during the day, but reduced Ωa under acidification and high flow. Nighttime changes in Ωa by corals were highly negative (0.6–0.8 h−1 and exacerbated by acidification. Calcifying macroalgae (Halimeda spp. raised Ωa by day (by around 0.13 h−1, but lowered Ωa by a similar or higher amount at night. Analyses of carbon flux contributions from benthic communities with four different compositions to the reef water carbon chemistry across Heron Reef flat and lagoon indicated that the net lowering of Ωa by coral-dominated areas can to some extent be countered by long water-residence times in neighbouring areas dominated by turfs, macroalgae and carbonate sand.

  12. Arrecifes de Coral: Una Coleccion de Actividades en Espanol para Estudiantes de Escuela Intermedia (Coral Reefs: A Spanish Compilation of Activities for Middle School Students).

    Science.gov (United States)

    Walker, Sharon H.; Newton, R. Amanda; Ortiz, Alida

    This activity book for middle school students on coral reefs is divided into 10 sections. Section 1 is the introduction. Section 2 describes what coral reefs are while section 3 describes how coral reefs reproduce and grow. Section 4 describes where coral reefs are found, and section 5 describes life on a coral reef. Section 6 describes the…

  13. Coral reef ecosystem decline: changing dynamics of coral reef carbonate production and implications for reef growth potential

    Science.gov (United States)

    Perry, Chris

    2016-04-01

    Global-scale deteriorations in coral reef health have caused major shifts in species composition and are likely to be exacerbated by climate change. It has been suggested that one effect of these ecological changes will be to lower reef carbonate production rates, which will impair reef growth potential and, ultimately, may lead to states of net reef erosion. However, quantitative data to support such assertions are limited, and linkages between the ecological state of coral reefs and their past and present geomorphic performance (in other words their growth potential) are poorly resolved. Using recently collected data from sites in the Caribbean and Indian Ocean, and which have undergone very different post-disturbance ecological trajectories over the last ~20-30 years, the differential impacts of disturbance on contemporary carbonate production regimes and on reef growth potential can be explored. In the Caribbean, a region which has been severely impacted ecological over the last 30+ years, our datasets show that average carbonate production rates on reefs are now less than 50% of pre-disturbance rates, and that calculated accretion rates (mm yr-1) are an about order of magnitude lower within shallow water habitats compared to Holocene averages. Collectively, these data suggest that recent ecological declines are now propagating through the system to impact on the geomorphic performance of Caribbean reefs and will impair their future growth potential. In contrast, the carbonate budgets of most reefs across the Chagos archipelago (central Indian Ocean), which is geographically remote and largely isolated from direct human disturbances, have recovered rapidly from major past disturbances (specifically the 1998 coral bleaching event). The carbonate budgets on these remote reefs now average +3.7 G (G = kg CaCO3 m-2 yr-1). Most significantly the production rates on Acropora-dominated reefs, which were most severely impacted by the 1998 bleaching event, average +8.4 G

  14. ReefSAM - Reef Sedimentary Accretion Model: A new 3D coral reef evolution model/simulator

    Science.gov (United States)

    Barrett, Samuel; Webster, Jody

    2013-04-01

    Coral reefs show characteristic morphological patterns (e.g. coral dominated margins with detrital carbonate dominated lagoons/back-reef) and temporal development (e.g. Hopley et al. 2007). While the processes which lead to predictable patterns on a range of scales have been discussed qualitatively, a full quantitative understanding of the range of processes and parameters involved requires modelling. Previous attempts to model complex Holocene reef systems (i.e. One Tree Reef, GBR - Barrett and Webster 2012) using a carbonate stratigraphic forward model (Carbonate3D - Warrlich et al. 2002) identified a number of important but unsimulated processes and potential model improvements. ReefSAM has been written from scratch in Matlab using these findings and experiences from using Carbonate3D. It simulates coralgal accretion and carbonate sand production and transport. Specific improvements include: 1. a more complex hydrodynamic model based on wave refraction and incorporating vertical (depth) and lateral (substrate dependent) variations in transport energy and erosion. 2. a complex reef growth model incorporating depth, wave energy/turbidity and substrate composition. 3. Paleo-water depth, paleo-wave energy and bio-zone (combination of paleo-water depth and wave energy) model outputs allowing coralgal habitat changes through time and space to be simulated and compared to observational data. The model is compared to the well studied One Tree Reef - tests similar to those undertaken in Barrett and Webster 2012 with Carbonate3D are presented. Model development coincides with plans for further intensive drilling at One Tree Reef (mid 2013) providing an opportunity to test the model predictively. The model is still in active development. References: Barrett, S.J., Webster, J.M.,2012. Holocene evolution of the Great Barrier Reef: Insights from 3D numerical modelling. Sedimentary Geology 265-266, 56-71. Warrlich, G.M.D., Waltham, D.A., Bosence D.W.J., 2002. Quantifying the

  15. The role of coral reef rugosity in dissipating wave energy and coastal protection

    Science.gov (United States)

    Harris, Daniel; Rovere, Alessio; Parravicini, Valeriano; Casella, Elisa

    2016-04-01

    Coral reefs are the most effective natural barrier in dissipating wave energy through breaking and bed friction. The attenuation of wave energy by coral reef flats is essential in the protection and stability of coral reef aligned coasts and reef islands. However, the effectiveness of wave energy dissipation by coral reefs may be diminished under future climate change scenarios with a potential reduction of coral reef rugosity due to increased stress environmental stress on corals. The physical roughness or rugosity of coral reefs is directly related to ecological diversity, reef health, and hydrodynamic roughness. However, the relationship between physical roughness and hydrodynamic roughness is not well understood despite the crucial role of bed friction in dissipating wave energy in coral reef aligned coasts. We examine the relationship between wave energy dissipation across a fringing reef in relation to the cross-reef ecological zonation and the benthic hydrodynamic roughness. Waves were measured by pressure transducers in a cross-reef transect on the reefs flats and post processed on a wave by wave basis to determine wave statistics such as significant wave height and wave period. Results from direct wave measurement were then used to calibrate a 1D wave dissipation model that incorporates dissipation functions due to bed friction and wave breaking. This model was used to assess the bed roughness required to produce the observed wave height dissipation during propagation from deep water and across the coral reef flats. Changes in wave dissipation was also examined under future scenarios of sea level rise and reduced bed roughness. Three dimensional models of the benthic reef structure were produced through structure-from-motion photogrammetry surveys. Reef rugosity was then determined from these surveys and related to the roughness results from the calibrated model. The results indicate that applying varying roughness coefficients as the benthic ecological

  16. Habitat dynamics, marine reserve status, and the decline and recovery of coral reef fish communities.

    Science.gov (United States)

    Williamson, David H; Ceccarelli, Daniela M; Evans, Richard D; Jones, Geoffrey P; Russ, Garry R

    2014-02-01

    Severe climatic disturbance events often have major impacts on coral reef communities, generating cycles of decline and recovery, and in some extreme cases, community-level phase shifts from coral-to algal-dominated states. Benthic habitat changes directly affect reef fish communities, with low coral cover usually associated with low fish diversity and abundance. No-take marine reserves (NTRs) are widely advocated for conserving biodiversity and enhancing the sustainability of exploited fish populations. Numerous studies have documented positive ecological and socio-economic benefits of NTRs; however, the ability of NTRs to ameliorate the effects of acute disturbances on coral reefs has seldom been investigated. Here, we test these factors by tracking the dynamics of benthic and fish communities, including the important fishery species, coral trout (Plectropomus spp.), over 8 years in both NTRs and fished areas in the Keppel Island group, Great Barrier Reef, Australia. Two major disturbances impacted the reefs during the monitoring period, a coral bleaching event in 2006 and a freshwater flood plume in 2011. Both disturbances generated significant declines in coral cover and habitat complexity, with subsequent declines in fish abundance and diversity, and pronounced shifts in fish assemblage structure. Coral trout density also declined in response to the loss of live coral, however, the approximately 2:1 density ratio between NTRs and fished zones was maintained over time. The only post-disturbance refuges for coral trout spawning stocks were within the NTRs that escaped the worst effects of the disturbances. Although NTRs had little discernible effect on the temporal dynamics of benthic or fish communities, it was evident that the post-disturbance refuges for coral trout spawning stocks within some NTRs may be critically important to regional-scale population persistence and recovery. PMID:24634720

  17. Herbivore space use influences coral reef recovery.

    Science.gov (United States)

    Eynaud, Yoan; McNamara, Dylan E; Sandin, Stuart A

    2016-06-01

    Herbivores play an important role in marine communities. On coral reefs, the diversity and unique feeding behaviours found within this functional group can have a comparably diverse set of impacts in structuring the benthic community. Here, using a spatially explicit model of herbivore foraging, we explore how the spatial pattern of grazing behaviours impacts the recovery of a reef ecosystem, considering movements at two temporal scales-short term (e.g. daily foraging patterns) and longer term (e.g. monthly movements across the landscape). Model simulations suggest that more spatially constrained herbivores are more effective at conferring recovery capability by providing a favourable environment to coral recruitment and growth. Results also show that the composition of food available to the herbivore community is linked directly to the pattern of space use by herbivores. To date, most studies of variability among the impacts of herbivore species have considered the diversity of feeding modes and mouthparts. Our work provides a complementary view of spatial patterns of foraging, revealing that variation in movement behaviours alone can affect patterns of benthic change, and thus broadens our view of realized links between herbivore diversity and reef recovery. PMID:27429784

  18. Patterns of the benthic community structure in coral reefs of the north western Caribbean

    OpenAIRE

    Borges-Souza, J.M.; Chávez, E.A.

    2007-01-01

    Data on the benthic community structure of six coral reefs of the Mexican portion of the Mesoamerican Barrier Reef System using the photographic-transect method, aimed to describe the structural patterns in each reef, and comparing differences between shallow and deep reefs. In the shallow stratum (Colombia 6-7m, Chankanaab 6m, Majahual 1-6m and Akumal 8m) hexacorals, sponges and algae dominated, with 38%, 34.6% and 14.5% of abundance, respectively. The species most commonly found were: Monta...

  19. Threatened reef corals of the world.

    Directory of Open Access Journals (Sweden)

    Danwei Huang

    Full Text Available A substantial proportion of the world's living species, including one-third of the reef-building corals, are threatened with extinction and in pressing need of conservation action. In order to reduce biodiversity loss, it is important to consider species' contribution to evolutionary diversity along with their risk of extinction for the purpose of setting conservation priorities. Here I reconstruct the most comprehensive tree of life for the order Scleractinia (1,293 species that includes all 837 living reef species, and employ a composite measure of phylogenetic distinctiveness and extinction risk to identify the most endangered lineages that would not be given top priority on the basis of risk alone. The preservation of these lineages, not just the threatened species, is vital for safeguarding evolutionary diversity. Tests for phylogeny-associated patterns show that corals facing elevated extinction risk are not clustered on the tree, but species that are susceptible, resistant or resilient to impacts such as bleaching and disease tend to be close relatives. Intensification of these threats or extirpation of the endangered lineages could therefore result in disproportionate pruning of the coral tree of life.

  20. Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems

    OpenAIRE

    Laura Rix; de Goeij, Jasper M.; Mueller, Christina E.; Ulrich Struck; Middelburg, Jack J.; van Duyl, Fleur C.; Al-Horani, Fuad A.; Christian Wild; Naumann, Malik S.; Dick van Oevelen

    2016-01-01

    Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated....

  1. Functionally diverse reef-fish communities ameliorate coral disease

    OpenAIRE

    Raymundo, Laurie J.; Halford, Andrew R.; Maypa, Aileen P.; Kerr, Alexander M.

    2009-01-01

    Coral reefs, the most diverse of marine ecosystems, currently experience unprecedented levels of degradation. Diseases are now recognized as a major cause of mortality in reef-forming corals and are complicit in phase shifts of reef ecosystems to algal-dominated states worldwide. Even so, factors contributing to disease occurrence, spread, and impact remain poorly understood. Ecosystem resilience has been linked to the conservation of functional diversity, whereas overfishing reduces function...

  2. Management of Bleached and Severely Damaged Coral Reefs

    OpenAIRE

    Westmacott, Susie; Teleki, Kristian; Wells, Sue; West, Jordan

    2000-01-01

    Coral reefs are one of the most threatened ecosystems in the world. Rivalling terrestrial rainforests in their biological diversity, and providing major economic benefits from fisheries and tourism, coral reefs ecosystems are of global concern. In addition, reefs provide many vital functions in developing countries, especially in Small Island Developing States. Until recently, stresses caused by human activities – such as land-based sources of pollution and destructive...

  3. Residence times of neutrally-buoyant matter such as larvae, sewage or nutrients on coral reefs

    Science.gov (United States)

    Black, Kerry P.; Gay, Stephen L.; Andrews, John C.

    1990-12-01

    Coral reef flushing times at an individual reef scale are specified and a general formula to determine these times is developed. The formula is confirmed by comparison with residence times predicted by numerical small-scale reef models, including those from a 4 month unsteady current simulation of John Brewer Reef on Australia's Great Barrier Reef. The method proves to be a satisfactory alternative to the numerical modelling. When neutrally-buoyant material around a reef is removed by the currents, the concentrations decay exponentially. The decay rate depends primarily on free stream current and reef dimensions. Secondary factors are the tidal excursion, shelf depth, lagoon size and residual current in the lee of the reef. These factors, when combined into a decay coefficient, specify the rate of loss of neutrally-buoyant material (e.g. some larvae, pollutants and sewage) from a coral reef and its surrounds. The analytical formula can be used to predict the flushing rates or the percentage of material still remaining on a reef after a selected time interval. We demonstrate that material can remain on or near typical reefs in common weather conditions for several weeks.

  4. THE CONDITION OF CORAL REEFS IN SOUTH FLORIDA (2000) USING CORAL DISEASE AND BLEACHING AS INDICATORS

    Science.gov (United States)

    The destruction for coral reef habitats is occurring at unprecedented levels. Coral disease epizootics in the Southwestern Atlantic have lead to coral replacement by turf algae, prompting a call to classify some coral species as endangered. In addition, a massive bleaching event ...

  5. Coral Reefs: Their Functions, Threats and Economic Value

    OpenAIRE

    Cesar, H.S.J.

    2002-01-01

    Coral reef ecosystems provide many functions, services and goods to coastal populations, especially in the developing world. A variety of anthropogenic practices threatens reef health and therefore jeopardises the benefits flowing from these services and goods. These threats range from local pollution, sedimentation, destructive fishing practices and coral mining to global issues like coral bleaching. Economic valuation can help to shed light to the importance of the serv...

  6. Coral community response to bleaching on a highly disturbed reef

    OpenAIRE

    Guest, J R; Low, J.; Tun, K.; Wilson, B.; Ng, C.; D. Raingeard; Ulstrup, K. E.; Tanzil, J. T. I.; Todd, P.A.; Toh, T. C.; McDougald, D; Chou, L. M.; Steinberg, P D

    2016-01-01

    While many studies of coral bleaching report on broad, regional scale responses, fewer examine variation in susceptibility among coral taxa and changes in community structure, before, during and after bleaching on individual reefs. Here we report in detail on the response to bleaching by a coral community on a highly disturbed reef site south of mainland Singapore before, during and after a major thermal anomaly in 2010. To estimate the capacity for resistance to thermal stress, we report on:...

  7. River discharge reduces reef coral diversity in Palau.

    Science.gov (United States)

    Golbuu, Yimnang; van Woesik, Robert; Richmond, Robert H; Harrison, Peter; Fabricius, Katharina E

    2011-04-01

    Coral community structure is often governed by a suite of processes that are becoming increasingly influenced by land-use changes and related terrestrial discharges. We studied sites along a watershed gradient to examine both the physical environment and the associated biological communities. Transplanted corals showed no differences in growth rates and mortality along the watershed gradient. However, coral cover, coral richness, and coral colony density increased with increasing distance from the mouth of the bay. There was a negative relationship between coral cover and mean suspended solids concentration. Negative relationships were also found between terrigenous sedimentation rates and the richness of adult and juvenile corals. These results have major implications not only for Pacific islands but for all countries with reef systems downstream of rivers. Land development very often leads to increases in river runoff and suspended solids concentrations that reduce coral cover and coral diversity on adjacent reefs. PMID:21251680

  8. Classification of remote Pacific coral reefs by physical oceanographic environment

    Science.gov (United States)

    Freeman, Lauren A.; Miller, Arthur J.; Norris, Richard D.; Smith, Jennifer E.

    2012-02-01

    The oceanographic environment is a key element in structuring coral reef ecosystems by setting the range of physical and chemical conditions in which coral reef-builders live. A cluster analysis of physical and chemical oceanographic data is used to classify coral habitats in the remote tropical and subtropical Pacific Ocean based on average temperature, temperature seasonal cycle, nutrient levels, salinity, aragonite saturation state, storm frequency, intense hurricane hits, and dissolved oxygen as well as temperature anomalies in degree heating weeks. The resulting seven geographic habitats are stable to perturbations in types of data used in the cluster analysis. Based on recent coral reef survey data in the area, the coral cover was related to the identified geographic regions. The habitats tend to be geographically clustered, and each is characterized by a unique combination of oceanographic conditions. Previous studies suggest coral reef habitats are associated with a uniform array of oceanographic conditions, while our results demonstrate that finer-scale variations in physical variables may control coral reef environments. The results better define the physical environment of remote coral reefs, forming a foundation for future work addressing physical habitat perturbation and anthropogenic impacts on reefs.

  9. Comparative studies on the status of Indonesian coral reefs

    Science.gov (United States)

    Soekarno, R.

    Coral reefs are of great economic importance for Indonesia. Unfortunately these resources are suffering from increasing human pressure. Several factors may cause the degradation of coral reefs, including the consequences of several human activities. Activities indirectly affecting the quality of the reefs are land-based activities such as deforestation, agriculture intensification, industrialization and domestic waste disposal. Direct use of the reefs, e.g. by coral mining, fish blasting and other fishing and collecting activities, is of greater and more widespread importance. Therefore, a rational management of the reef resources is urgently needed. Management is impossible without simple means of monitoring the status of reefs. One factor, living coral cover, has been determined for several years in many areas, including those studied during the Snellius-II Expedition. This allowed a comparative study of several different areas, which showed that coral cover is often very useful as an indication of the quality of reefs. It was found that the diversity of reef fishes is correlated with the condition of reefs as determined by the percentage cover of living coral.

  10. National Coral Reef Monitoring Program: Stratified Random surveys (StRS) of coral demography (adult and juvenile corals) since 2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific Reef Assessment and Monitoring Program (Pacific RAMP), established by CRED and supported by NOAA's Coral Reef Conservation Program (CRCP), is tasked with...

  11. Coral recovery may not herald the return of fishes on damaged coral reefs

    KAUST Repository

    Bellwood, David R.

    2012-03-25

    The dynamic nature of coral reefs offers a rare opportunity to examine the response of ecosystems to disruption due to climate change. In 1998, the Great Barrier Reef experienced widespread coral bleaching and mortality. As a result, cryptobenthic fish assemblages underwent a dramatic phase-shift. Thirteen years, and up to 96 fish generations later, the cryptobenthic fish assemblage has not returned to its pre-bleach configuration. This is despite coral abundances returning to, or exceeding, pre-bleach values. The post-bleach fish assemblage exhibits no evidence of recovery. If these short-lived fish species are a model for their longer-lived counterparts, they suggest that (1) the full effects of the 1998 bleaching event on long-lived fish populations have yet to be seen, (2) it may take decades, or more, before recovery or regeneration of these long-lived species will begin, and (3) fish assemblages may not recover to their previous composition despite the return of corals. © 2012 Springer-Verlag.

  12. Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems.

    Science.gov (United States)

    Rix, Laura; de Goeij, Jasper M; Mueller, Christina E; Struck, Ulrich; Middelburg, Jack J; van Duyl, Fleur C; Al-Horani, Fuad A; Wild, Christian; Naumann, Malik S; van Oevelen, Dick

    2016-01-01

    Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated. Here we used laboratory stable isotope tracer experiments to show the transfer of coral mucus into the bulk tissue and phospholipid fatty acids of the warm-water sponge Mycale fistulifera and cold-water sponge Hymedesmia coriacea, demonstrating a direct trophic link between corals and reef sponges. Furthermore, 21-40% of the mucus carbon and 32-39% of the nitrogen assimilated by the sponges was subsequently released as detritus, confirming a sponge loop on Red Sea warm-water and north Atlantic cold-water coral reefs. The presence of a sponge loop in two vastly different reef environments suggests it is a ubiquitous feature of reef ecosystems contributing to the high biogeochemical cycling that may enable coral reefs to thrive in nutrient-limited (warm-water) and energy-limited (cold-water) environments. PMID:26740019

  13. Benthic buffers and boosters of ocean acidification on coral reefs

    Directory of Open Access Journals (Sweden)

    K. R. N. Anthony

    2013-02-01

    Full Text Available Ocean acidification is a threat to marine ecosystems globally. In shallow-water systems, however, ocean acidification can be masked by benthic carbon fluxes, depending on community composition, seawater residence time, and the magnitude and balance of net community production (pn and calcification (gn. Here, we examine how six benthic groups from a coral reef environment on Heron Reef (Great Barrier Reef, Australia contribute to changes in seawater aragonite saturation state (Ωa. Results of flume studies showed a hierarchy of responses across groups, depending on CO2 level, time of day and water flow. At low CO2 (350–450 μatm, macroalgae (Chnoospora implexa, turfs and sand elevated Ωa of the flume water by around 0.10 to 1.20 h−1 – normalised to contributions from 1 m2 of benthos to a 1 m deep water column. The rate of Ωa increase in these groups was doubled under acidification (560–700 μatm and high flow (35 compared to 8 cm s−1. In contrast, branching corals (Acropora aspera increased Ωa by 0.25 h−1 at ambient CO2 (350–450 μatm during the day, but reduced Ωa under acidification and high flow. Nighttime changes in Ωa by corals were highly negative (0.6–0.8 h−1 and exacerbated by acidification. Calcifying macroalgae (Halimeda spp. raised Ωa by day (by around 0.13 h−1, but lowered Ωa by a similar or higher amount at night. Analyses of carbon flux contributions from four different benthic compositions to the reef water carbon chemistry across Heron Reef flat and lagoon indicated that the net lowering of Ωa by coral-dominated areas can to some extent be countered by long water residence times in neighbouring areas dominated by turfs, macroalgae and potentially sand.

  14. Fifty million years of herbivory on coral reefs: fossils, fish and functional innovations

    OpenAIRE

    Bellwood, D. R.; Goatley, C. H. R.; Brandl, S. J.; Bellwood, O.

    2014-01-01

    The evolution of ecological processes on coral reefs was examined based on Eocene fossil fishes from Monte Bolca, Italy and extant species from the Great Barrier Reef, Australia. Using ecologically relevant morphological metrics, we investigated the evolution of herbivory in surgeonfishes (Acanthuridae) and rabbitfishes (Siganidae). Eocene and Recent surgeonfishes showed remarkable similarities, with grazers, browsers and even specialized, long-snouted forms having Eocene analogues. These lon...

  15. Coral Reef Monitoring: From Cytological Parameters to Community Indices

    Directory of Open Access Journals (Sweden)

    Ofer Ben-Tzvi

    2011-01-01

    Full Text Available Sound-ecosystem-based management of coral reefs is largely based on indicators of reef health state. Currently there are various ecological parameters that serve as reef state indices; however, their practical implications are under debate. In the present study we examine an alternative parameter, the deterioration index (DI, which does not purport to replace the traditional indices but can provide a reliable, stand-alone indication of reef state. Patterns of cytological indices, which are considered as reliable indicators of environmental stressors, have been compared to ten selected reef community indices. The DI showed the highest correlations among community indices to the cytological indices in artificial reefs and high correlation in natural reefs as well. Our results suggest that in cases of lacking adequate monitoring abilities where a full set of community indices cannot be obtained, the DI can serve in many cases as the preferred, stand-alone indicator of coral reef state.

  16. Coral mortality in reefs: The cause and effect; A central concern for reef monitoring

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.

    stream_size 4 stream_content_type text/plain stream_name Region_Workshop_Conserv_Sustain_Mgmt_Coral_Reefs_1997_C83.pdf.txt stream_source_info Region_Workshop_Conserv_Sustain_Mgmt_Coral_Reefs_1997_C83.pdf.txt Content-Encoding ISO-8859...

  17. Recovery of an isolated coral reef system following severe disturbance.

    Science.gov (United States)

    Gilmour, James P; Smith, Luke D; Heyward, Andrew J; Baird, Andrew H; Pratchett, Morgan S

    2013-04-01

    Coral reef recovery from major disturbance is hypothesized to depend on the arrival of propagules from nearby undisturbed reefs. Therefore, reefs isolated by distance or current patterns are thought to be highly vulnerable to catastrophic disturbance. We found that on an isolated reef system in north Western Australia, coral cover increased from 9% to 44% within 12 years of a coral bleaching event, despite a 94% reduction in larval supply for 6 years after the bleaching. The initial increase in coral cover was the result of high rates of growth and survival of remnant colonies, followed by a rapid increase in juvenile recruitment as colonies matured. We show that isolated reefs can recover from major disturbance, and that the benefits of their isolation from chronic anthropogenic pressures can outweigh the costs of limited connectivity. PMID:23559247

  18. Ocean acidification accelerates dissolution of experimental coral reef communities

    Directory of Open Access Journals (Sweden)

    S. Comeau

    2014-08-01

    Full Text Available Ocean acidification (OA poses a severe threat to tropical coral reefs, yet much of what is know about these effects comes from individual corals and algae incubated in isolation under high pCO2. Studies of similar effects on coral reef communities are scarce. To investigate the response of coral reef communities to OA, we used large outdoor flumes in which communities composed of calcified algae, corals, and sediment were combined to match the percentage cover of benthic communities in the shallow back reef of Moorea, French Polynesia. Reef communities in the flumes were exposed to ambient (~400 μatm and high pCO2 (~1300 μatm for 8 weeks, and calcification rates measured for the constructed communities including the sediments. Community calcification was depressed 59% under high pCO2, with sediment dissolution explaining ~50% of this decrease; net calcification of corals and calcified algae remained positive, but was reduced 29% under elevated pCO2. These results show that despite the capacity of coral reef calcifiers to maintain positive net accretion of calcium carbonate under OA conditions, reef communities might switch to net dissolution as pCO2 increases, particularly at night, due to enhanced sediment dissolution.

  19. Photochemical activity in waters of the Great Barrier Reef

    Science.gov (United States)

    Szymczak, R.; Waite, T. D.

    1991-12-01

    Photochemical activity in waters of the Great Barrier Reef was investigated through studies on the vertical, horizontal and temporal distribution of hydrogen peroxide and factors influencing its generation and decay processes. Surface hydrogen peroxide concentrations varied from 15 to 110 nM and generally decreased with depth, though a number of anomalies were detected. Photochemical activity decreased with increasing distance from the coast reflecting the positive influence of terrestrial inputs to the hydrogen peroxide generation and decay processes. Increases in photochemical activity were observed in the proximity of coral reefs. Hydrogen peroxide concentrations in the region were influenced by wind-induced mixing processes, atmospheric inputs, anthropogenic activity and seasonal light regimes.

  20. The status of coral reef ecology research in the Red Sea

    KAUST Repository

    Berumen, Michael L.

    2013-06-21

    The Red Sea has long been recognized as a region of high biodiversity and endemism. Despite this diversity and early history of scientific work, our understanding of the ecology of coral reefs in the Red Sea has lagged behind that of other large coral reef systems. We carried out a quantitative assessment of ISI-listed research published from the Red Sea in eight specific topics (apex predators, connectivity, coral bleaching, coral reproductive biology, herbivory, marine protected areas, non-coral invertebrates and reef-associated bacteria) and compared the amount of research conducted in the Red Sea to that from Australia\\'s Great Barrier Reef (GBR) and the Caribbean. On average, for these eight topics, the Red Sea had 1/6th the amount of research compared to the GBR and about 1/8th the amount of the Caribbean. Further, more than 50 % of the published research from the Red Sea originated from the Gulf of Aqaba, a small area (<2 % of the area of the Red Sea) in the far northern Red Sea. We summarize the general state of knowledge in these eight topics and highlight the areas of future research priorities for the Red Sea region. Notably, data that could inform science-based management approaches are badly lacking in most Red Sea countries. The Red Sea, as a geologically "young" sea located in one of the warmest regions of the world, has the potential to provide insight into pressing topics such as speciation processes as well as the capacity of reef systems and organisms to adapt to global climate change. As one of the world\\'s most biodiverse coral reef regions, the Red Sea may yet have a significant role to play in our understanding of coral reef ecology at a global scale. © 2013 Springer-Verlag Berlin Heidelberg.

  1. The interaction of ocean acidification and carbonate chemistry on coral reef calcification: evaluating the carbonate chemistry Coral Reef Ecosystem Feedback (CREF hypothesis on the Bermuda coral reef

    Directory of Open Access Journals (Sweden)

    N. R. Bates

    2009-07-01

    Full Text Available Despite the potential impact of ocean acidification on ecosystems such as coral reefs, surprisingly, there is very limited field data on the relationships between calcification and carbonate chemistry. In this study, contemporaneous in situ datasets of carbonate chemistry and calcification rates from the high-latitude coral reef of Bermuda over annual timescales provide a framework for investigating the present and future potential impact of rising pCO2 and ocean acidification on coral reef ecosystems in their natural environment. A strong correlation was found between the in situ rates of calcification for the major framework building coral species Diploria labyrinthiformis and the seasonal variability of [CO32-] and Ωaragonite, rather than other environmental factors such as light and temperature. These field observations also provide sufficient data to hypothesize that there is a seasonal "Carbonate Chemistry Coral Reef Ecosystem Feedback" (CREF hypothesis between the primary components of the reef ecosystem (i.e. scleractinian hard corals and macroalgae and carbonate chemistry. In early summer, strong net autotrophy from benthic components of the reef system enhance [CO32-] and Ωaragonite conditions, and rates of coral calcification due to the photosynthetic uptake of CO2. In late summer, rates of coral calcification are suppressed by release of CO2 from reef metabolism during a period of strong net heterotrophy. It is likely that this seasonal CREF mechanism is present in other tropical reefs although attenuated compared to high-latitude reefs such as Bermuda. Due to lower annual mean surface seawater [CO32-] and Ωaragonite in Bermuda compared to tropical regions, we anticipate that Bermuda corals will experiences seasonal periods of zero net calcification within the next decade at [CO

  2. Effects of changing temperatures on coral reef health: Implications for management

    Science.gov (United States)

    Selig, Elizabeth Rose

    Human-induced climate change has already led to substantial changes in a variety of ecosystems. Coral reefs are particularly vulnerable to rises in ocean temperature as a result of climate change because they already live near their thermal limits. However, we know little about the spatial patterns of temperature anomalies, areas of greater than usual temperature, which cause coral mortality and increased rates of coral disease. These gaps in knowledge make it difficult to design effective management strategies for mitigating the effects of ocean warming. My dissertation research uses a combination of a new satellite ocean temperature dataset, field surveys on coral health, and data on marine protected area (MPA) boundaries to analyze how ocean temperatures are affecting coral reef health at regional and global scales. I discovered that temperature anomalies are spatially and temporally variable from 1985-2005 even during El Nino events. They are also typically less than 50 km2, smaller than the resolution of many climate models. In addition, I found a strong relationship on the Great Barrier Reef between the number of temperature anomalies and the number of cases of white syndrome, a prevalent coral disease. Results from this study suggest that temperature anomalies are playing a major role in the observed decline of coral reefs over the last 30-40 years. This decline highlights the importance of determining whether MPAs, one of the most common management tools are effective in restoring coral cover. My analyses demonstrated that MPAs can confer some ecosystem resilience through fisheries management and land management practices at regional scales. Coral cover on reefs inside of MPAs did not change over time, while unprotected reefs experienced declines in coral cover. However, MPAs do not moderate the effect of thermal stress on corals or reduce coral decline at rates that can offset losses from thermal stress and other major natural and human-caused disturbances

  3. Coral reef diseases in the Atlantic-Caribbean

    Science.gov (United States)

    Rogers, Caroline S.; Weil, Ernesto

    2010-01-01

    Coral reefs are the jewels of the tropical oceans. They boast the highest diversity of all marine ecosystems, aid in the development and protection of other important, productive coastal marine communities, and have provided millions of people with food, building materials, protection from storms, recreation and social stability over thousands of years, and more recently, income, active pharmacological compounds and other benefits. These communities have been deteriorating rapidly in recent times. The continuous emergence of coral reef diseases and increase in bleaching events caused in part by high water temperatures among other factors underscore the need for intensive assessments of their ecological status and causes and their impact on coral reefs.

  4. Quantifying climatological ranges and anomalies for Pacific coral reef ecosystems.

    Directory of Open Access Journals (Sweden)

    Jamison M Gove

    Full Text Available Coral reef ecosystems are exposed to a range of environmental forcings that vary on daily to decadal time scales and across spatial scales spanning from reefs to archipelagos. Environmental variability is a major determinant of reef ecosystem structure and function, including coral reef extent and growth rates, and the abundance, diversity, and morphology of reef organisms. Proper characterization of environmental forcings on coral reef ecosystems is critical if we are to understand the dynamics and implications of abiotic-biotic interactions on reef ecosystems. This study combines high-resolution bathymetric information with remotely sensed sea surface temperature, chlorophyll-a and irradiance data, and modeled wave data to quantify environmental forcings on coral reefs. We present a methodological approach to develop spatially constrained, island- and atoll-scale metrics that quantify climatological range limits and anomalous environmental forcings across U.S. Pacific coral reef ecosystems. Our results indicate considerable spatial heterogeneity in climatological ranges and anomalies across 41 islands and atolls, with emergent spatial patterns specific to each environmental forcing. For example, wave energy was greatest at northern latitudes and generally decreased with latitude. In contrast, chlorophyll-a was greatest at reef ecosystems proximate to the equator and northern-most locations, showing little synchrony with latitude. In addition, we find that the reef ecosystems with the highest chlorophyll-a concentrations; Jarvis, Howland, Baker, Palmyra and Kingman are each uninhabited and are characterized by high hard coral cover and large numbers of predatory fishes. Finally, we find that scaling environmental data to the spatial footprint of individual islands and atolls is more likely to capture local environmental forcings, as chlorophyll-a concentrations decreased at relatively short distances (>7 km from 85% of our study locations

  5. Quantifying climatological ranges and anomalies for Pacific coral reef ecosystems.

    Science.gov (United States)

    Gove, Jamison M; Williams, Gareth J; McManus, Margaret A; Heron, Scott F; Sandin, Stuart A; Vetter, Oliver J; Foley, David G

    2013-01-01

    Coral reef ecosystems are exposed to a range of environmental forcings that vary on daily to decadal time scales and across spatial scales spanning from reefs to archipelagos. Environmental variability is a major determinant of reef ecosystem structure and function, including coral reef extent and growth rates, and the abundance, diversity, and morphology of reef organisms. Proper characterization of environmental forcings on coral reef ecosystems is critical if we are to understand the dynamics and implications of abiotic-biotic interactions on reef ecosystems. This study combines high-resolution bathymetric information with remotely sensed sea surface temperature, chlorophyll-a and irradiance data, and modeled wave data to quantify environmental forcings on coral reefs. We present a methodological approach to develop spatially constrained, island- and atoll-scale metrics that quantify climatological range limits and anomalous environmental forcings across U.S. Pacific coral reef ecosystems. Our results indicate considerable spatial heterogeneity in climatological ranges and anomalies across 41 islands and atolls, with emergent spatial patterns specific to each environmental forcing. For example, wave energy was greatest at northern latitudes and generally decreased with latitude. In contrast, chlorophyll-a was greatest at reef ecosystems proximate to the equator and northern-most locations, showing little synchrony with latitude. In addition, we find that the reef ecosystems with the highest chlorophyll-a concentrations; Jarvis, Howland, Baker, Palmyra and Kingman are each uninhabited and are characterized by high hard coral cover and large numbers of predatory fishes. Finally, we find that scaling environmental data to the spatial footprint of individual islands and atolls is more likely to capture local environmental forcings, as chlorophyll-a concentrations decreased at relatively short distances (>7 km) from 85% of our study locations. These metrics will help

  6. Economic value of coral reef and management effectiveness in Trao Reef locally managed marine reserve

    OpenAIRE

    Do, Hung Nguyen

    2009-01-01

    Trao Reef Locally Managed Marine Reserve was established in 2001 to protect coral reef being under threat because of human activities. However, the economic value of coral reef represents an important sight to help local people and resource managers in using and managing the resource effectively in the marine reserve has not been seen. By using financial analysis to calculate producer surplus of resource users, this study evaluated the direct use value consisting of fishery and aquaculture va...

  7. 77 FR 25407 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the...

    Science.gov (United States)

    2012-04-30

    ..., and South Atlantic; Coral and Coral Reefs Off the Southern Atlantic States; Exempted Fishing Permit... conditions, various species of reef fish, crabs, and lobsters in Federal waters off South Carolina and...

  8. Community structure and coral status across reef fishing intensity gradients in Palk Bay reef, southeast coast of India.

    Science.gov (United States)

    Manikandan, B; Ravindran, J; Shrinivaasu, S; Marimuthu, N; Paramasivam, K

    2014-10-01

    Coral reef fishes are exploited without the knowledge of their sustainability and their possible effect in altering the community structure of a coral reef ecosystem. Alteration of the community structure could cause a decline in the health of coral reefs and its services. We documented the coral community structure, status of live corals and reef fish assemblages in Palk Bay at the reef fishing hotspots and its nearby reef area with minimum fishing pressure and compared it with a control reef area where reef fishing was banned for more than two decades. The comparison was based on the percent cover of different forms of live corals, their diversity and the density and diversity of reef fishes. The reef fish stock in the reef fishing hotspots and its neighbouring reef was lower by 61 and 38%, respectively compared to the control reef. The herbivore fish Scarus ghobban and Siganus javus were exploited at a rate of 250 and 105 kg month(-1) fishermen(-1), respectively, relatively high comparing the small reef area. Live and dead corals colonized by turf algae were predominant in both the reef fishing hotspots and its nearby coral ecosystems. The percent cover of healthy live corals and live corals colonized by turf algae was 80%, respectively, in the intensively fished coral ecosystems. The corals were less diverse and the massive Porites and Favia colonies were abundant in the intensive reef fishing sites. Results of this study suggest that the impact of reef fish exploitation was not solely restricted to the intensively fished reefs, but also to the nearby reefs which play a critical role in the resilience of degraded reef ecosystems. PMID:24859909

  9. ESR dosimetric properties of modern coral reef

    International Nuclear Information System (INIS)

    Modern coral reef samples from Egypt were irradiated with 60Coγ-rays to study radicals for dosimetric materials with electron spin resonance (ESR). The ESR spectrum for the radical species in unirradiated coral is characterized by four signals with spectroscopic splitting factors of g=2.0056, 2.0030, 2.0006 and 1.997. The signal at g=2.0006±0.0005 is ascribed to free rotation CO2- radicals and used as a dosimetric one. The response to γ-ray doses ranging from 5 to 103 Gy and the thermal stability has been studied. The number of free radicals per 100 eV (G-value) was found to be 0.45 ± 0.1 and 0.9 ± 0.18 for coral and alanine, respectively. The lifetime of radicals and the activation energy were estimated from Arrhenius plots to be approximately 8 x 105 ± 1.6 x 105 years, and 1.12 eV, respectively

  10. Anthropogenic mortality on coral reefs in Caribbean Panama predates coral disease and bleaching.

    Science.gov (United States)

    Cramer, Katie L; Jackson, Jeremy B C; Angioletti, Christopher V; Leonard-Pingel, Jill; Guilderson, Thomas P

    2012-06-01

    Caribbean reef corals have declined precipitously since the 1980s due to regional episodes of bleaching, disease and algal overgrowth, but the extent of earlier degradation due to localised historical disturbances such as land clearing and overfishing remains unresolved. We analysed coral and molluscan fossil assemblages from reefs near Bocas del Toro, Panama to construct a timeline of ecological change from the 19th century-present. We report large changes before 1960 in coastal lagoons coincident with extensive deforestation, and after 1960 on offshore reefs. Striking changes include the demise of previously dominant staghorn coral Acropora cervicornis and oyster Dendrostrea frons that lives attached to gorgonians and staghorn corals. Reductions in bivalve size and simplification of gastropod trophic structure further implicate increasing environmental stress on reefs. Our paleoecological data strongly support the hypothesis, from extensive qualitative data, that Caribbean reef degradation predates coral bleaching and disease outbreaks linked to anthropogenic climate change. PMID:22462739

  11. Biological impacts of oil pollution: coral reefs. V. 3

    International Nuclear Information System (INIS)

    Coral reefs are the largest structures made by living things and exist as extremely productive ecosystems in tropical and sub-tropical areas of the world. Their location in nearshore waters means that there is a potential danger to corals from tanker accidents, refinery operations, oil exploration and production. There are now a number of published scientific papers concerning the effects of oils on corals, but results are not entirely consistent. This report summarizes and interprets the findings, and provides background information on the structure and ecology of coral reefs. Clean-up options and their implications are discussed in the light of the latest evidence from case histories and field experiments. (UK)

  12. Coral Reef and Coastal Ecosystems Decision Support Workshop April 27-29, 2010 Caribbean Coral Reef Institute, La Parguera, Puerto Rico

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) and Caribbean Coral Reef Institute (CCRI) hosted a Coral Reef and Coastal Ecosystems Decision Support Workshop on April 27-28, 2010 at the Caribbean Coral Reef Institute in La Parguera, Puerto Rico. Forty-three participants, includin...

  13. Genetic markers for antioxidant capacity in a reef-building coral.

    Science.gov (United States)

    Jin, Young K; Lundgren, Petra; Lutz, Adrian; Raina, Jean-Baptiste; Howells, Emily J; Paley, Allison S; Willis, Bette L; van Oppen, Madeleine J H

    2016-05-01

    The current lack of understanding of the genetic basis underlying environmental stress tolerance in reef-building corals impairs the development of new management approaches to confronting the global demise of coral reefs. On the Great Barrier Reef (GBR), an approximately 51% decline in coral cover occurred over the period 1985-2012. We conducted a gene-by-environment association analysis across 12° latitude on the GBR, as well as both in situ and laboratory genotype-by-phenotype association analyses. These analyses allowed us to identify alleles at two genetic loci that account for differences in environmental stress tolerance and antioxidant capacity in the common coral Acropora millepora. The effect size for antioxidant capacity was considerable and biologically relevant (32.5 and 14.6% for the two loci). Antioxidant capacity is a critical component of stress tolerance because a multitude of environmental stressors cause increased cellular levels of reactive oxygen species. Our findings provide the first step toward the development of novel coral reef management approaches, such as spatial mapping of stress tolerance for use in marine protected area design, identification of stress-tolerant colonies for assisted migration, and marker-assisted selective breeding to create more tolerant genotypes for restoration of denuded reefs. PMID:27386515

  14. Synergistic effects of habitat preference and gregarious behaviour on habitat use in coral reef cardinalfish

    Science.gov (United States)

    Gardiner, N. M.; Jones, G. P.

    2010-12-01

    Spatial distributions of coral reef fish species are potentially determined by habitat preferences and behavioural interactions. However, the relative importance of these factors and whether or not behavioural interactions reinforce or disrupt habitat associations are poorly understood. This paper explores the degree to which habitat and social preferences explain the association that three common coral reef cardinalfish species ( Zoramia leptacanthus, Archamia zosterophora and Cheilodipterus quinquelineatus; family Apogonidae) have with coral substrata at Lizard Island, Great Barrier Reef. At diurnal resting sites, species were strongly associated with branching corals, with 80-90% of each species inhabiting one branching coral species, Porites cylindrica. Species were also highly gregarious, forming large con-specific and hetero-specific aggregations in coral heads, potentially reinforcing habitat associations. Three-way choice experiments were conducted to test fishes habitat preferences for living coral over dead substrata, for particular coral species, and the influence of gregarious behaviour on these habitat choices. The strength of habitat preferences differed among species, with Z. leptacanthus preferring live coral and P. cylindrica, A. zosterophora preferring P. cylindrica, whether live or dead and C. quinquelineatus exhibiting no preferences. All species were attracted to conspecifics, and for C. quinquelineatus and A. zosterophora, conspecific attraction resulted in stronger preferences for live corals. Gregarious behaviour also increased C. quinquelineatus associations with P. cylindrica. The relative strength of social attraction versus habitat preferences was investigated by comparing fish habitat preferences in the presence and/or absence of conspecifics. The presence of conspecifics on non-preferred rubble habitat reduced each species association with live coral. This study’s results indicate that in the field, habitat preferences and

  15. Coral diseases and their research in Colombian reefs

    International Nuclear Information System (INIS)

    Coral reefs are one of the most beautiful and important ecosystems in the planet. These ecosystems have existed for over 200 million years and have survived extreme episodes such as glaciation and mass extinctions during their history. Nonetheless, during the last three decades, these ecosystems have registered sudden and dramatic changes that, according to some researchers, endanger their survival and persistence. One of the major problems coral reefs are facing nowadays is the outbreak of diseases that affect corals, which constitute the basic unit of this ecosystem. There is no consensus regarding whether these disease outbreaks are recent episodes; but what seems to be true is that some of these diseases have favored unprecedented changes in coral reefs. Coral reefs in Colombia have also been affected by disease events, and since the 1980, several coral diseases have been observed and studied, and even one of them was first described in Colombian reefs. This work presents a compendium of the main coral diseases registered around the world and is meant to serve as a guide for new studies in this topic. Similarly, a summary of coral disease research carried out in Colombia is presented as well as a discussion on current perspectives for the study of this field in the country.

  16. ReefLink Database: A decision support tool for Linking Coral Reefs and Society Through Systems Thinking

    Science.gov (United States)

    Coral reefs provide the ecological foundation for productive and diverse fish and invertebrate communities that support multibillion dollar reef fishing and tourism industries. Yet reefs are threatened by growing coastal development, climate change, and over-exploitation. A key i...

  17. Coral-associated bacterial communities on Ningaloo Reef, Western Australia.

    Science.gov (United States)

    Ceh, Janja; Van Keulen, Mike; Bourne, David G

    2011-01-01

    Coral-associated microbial communities from three coral species (Pocillopora damicornis, Acropora tenuis and Favites abdita) were examined every 3 months (January, March, June, October) over a period of 1 year on Ningaloo Reef, Western Australia. Tissue from corals was collected throughout the year and additional sampling of coral mucus and seawater samples was performed in January. Tissue samples were also obtained in October from P. damicornis coral colonies on Rottnest Island off Perth, 1200 km south of Ningaloo Reef, to provide comparisons between coral-microbial associates in different locations. The community structures of the coral-associated microorganisms were analysed using phylogenetic analysis of 16S rRNA gene clone libraries, which demonstrated highly diverse microbial profiles among all the coral species sampled. Principal component analysis revealed that samples grouped according to time and not species, indicating that coral-microbial associations may be a result of environmental drivers such as oceanographic characteristics, benthic community structure and temperature. Tissue samples from P. damicornis at Rottnest Island revealed similarities in bacteria to the samples at Ningaloo Reef. This study highlights that coral-associated microbial communities are highly diverse; however, the complex interactions that determine the stability of these associations are not necessarily dependent on coral host specificity. PMID:21044100

  18. Validation of Reef-Scale Thermal Stress Satellite Products for Coral Bleaching Monitoring

    OpenAIRE

    Heron, Scott F.; Lyza Johnston; Gang Liu; Erick F. Geiger; Maynard, Jeffrey A; Jacqueline L. De La Cour; Steven Johnson; Ryan Okano; David Benavente; Timothy F. R. Burgess; John Iguel; Denise I. Perez; Skirving, William J.; Alan E. Strong; Kyle Tirak

    2016-01-01

    Satellite monitoring of thermal stress on coral reefs has become an essential component of reef management practice around the world. A recent development by the U.S. National Oceanic and Atmospheric Administration’s Coral Reef Watch (NOAA CRW) program provides daily global monitoring at 5 km resolution—at or near the scale of most coral reefs. In this paper, we introduce two new monitoring products in the CRW Decision Support System for coral reef management: Regional Virtual Stations, a reg...

  19. Additive Diversity Partitioning of Fish in a Caribbean Coral Reef Undergoing Shift Transition

    OpenAIRE

    Gilberto Acosta-González; Rodríguez-Zaragoza, Fabián A.; Hernández-Landa, Roberto C.; Arias-González, Jesús E.

    2013-01-01

    Shift transitions in dominance on coral reefs from hard coral cover to fleshy macroalgae are having negative effects on Caribbean coral reef communities. Data on spatiotemporal changes in biodiversity during these modifications are important for decision support for coral reef biodiversity protection. The main objective of this study is to detect the spatiotemporal patterns of coral reef fish diversity during this transition using additive diversity-partitioning analysis. We examined α, β and...

  20. Novel tradable instruments in the conservation of coral reefs, based on the coral gardening concept for reef restoration.

    Science.gov (United States)

    Rinkevich, Baruch

    2015-10-01

    Nearly all coral reefs bordering nations have experienced net losses in reef biodiversity, goods and services, even without considering the ever-developing global change impacts. In response, this overview wishes to reveal through prospects of active reef-restoration, the currently non-marketed or poorly marketed reef services, focusing on a single coral species (Stylophora pistillata). It is implied that the integration of equity capitals and other commodification with reef-restoration practices will improve total reef services. Two tiers of market-related activities are defined, the traditional first-tier instruments (valuating costs/gains for extracting tradable goods and services) and novel second-tier instruments (new/expanded monetary tools developed as by-products of reef restoration measures). The emerging new suite of economic mechanisms based on restoration methodologies could be served as an incentive for ecosystem conservation, enhancing the sum values of all services generated by coral reefs, where the same stocks of farmed/transplanted coral colonies will be used as market instruments. I found that active restoration measures disclose 12 classes of second-tier goods and services, which may partly/wholly finance restoration acts, bringing to light reef capitalizations that allow the expansion of markets with products that have not been considered before. The degree to which the second tier of market-related services could buffer coral-reef degradation is still unclear and would vary with different reef types and in various reef restoration scenarios; however, reducing the uncertainty associated with restoration. It is expected that the expansion of markets with the new products and the enhancement of those already existing will be materialized even if reef ecosystems will recover into different statuses. PMID:26241935

  1. Coral Reef Color: Remote and In-Situ Imaging Spectroscopy of Reef Structure and Function

    Science.gov (United States)

    Hochberg, E. J.

    2015-12-01

    Coral reefs are threatened at local to global scales by a litany of anthropogenic impacts, including overfishing, coastal development, marine and watershed pollution, rising ocean temperatures, and ocean acidification. However, available data for the primary indicator of coral reef condition — proportional cover of living coral — are surprisingly sparse and show patterns that contradict the prevailing understanding of how environment impacts reef condition. Remote sensing is the only available tool for acquiring synoptic, uniform data on reef condition at regional to global scales. Discrimination between coral and other reef benthos relies on narrow wavebands afforded by imaging spectroscopy. The same spectral information allows non-invasive quantification of photosynthetic pigment composition, which shows unexpected phenological trends. There is also potential to link biodiversity with optical diversity, though there has been no effort in that direction. Imaging spectroscopy underlies the light-use efficiency model for reef primary production by quantifying light capture, which in turn indicates biochemical capacity for CO2 assimilation. Reef calcification is strongly correlated with primary production, suggesting the possibility for an optics-based model of that aspect of reef function, as well. By scaling these spectral models for use with remote sensing, we can vastly improve our understanding of reef structure, function, and overall condition across regional to global scales. By analyzing those remote sensing products against ancillary environmental data, we can construct secondary models to predict reef futures in the era of global change. This final point is the objective of CORAL (COral Reef Airborne Laboratory), a three-year project funded under NASA's Earth Venture Suborbital-2 program to investigate the relationship between coral reef condition at the ecosystem scale and various nominal biogeophysical forcing parameters.

  2. NOAA's National Coral Reef Monitoring Program (NCRMP) Data Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Coral reefs provide nearly $30 billion in net benefits in goods and services to world economies each year, including tourism, fisheries, and coastal protection, and...

  3. Coral Reef Watch, Degree Heating Weeks, 50 km

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Coral Reef Watch distributes Degree Heating Week products using a combination of the POES AVHRR Global Area Coverage data, and data from a climatological...

  4. A Survey of Coral Reefs in South China Sea Completed

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ An investigation of coral reefs in South China Sea has recently completed by CAS scientists at South China Sea Institute of Oceanography (SCSIO) in Guangzhou. The compilation and analysis of the obtained data is now under way.

  5. Status of the Coral Reefs of the Samoan Archipelago

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this study are twofold: (1) To determine the current status of coral reef fishes and their habitat throughout the Samoan Archipelago. This will be...

  6. Postglacial fringing-reef to barrier-reef conversion on Tahiti links Darwin's reef types

    OpenAIRE

    Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

    2014-01-01

    In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial ...

  7. Reef-Scale Thermal Stress Monitoring of Coral Ecosystems: New 5-km Global Products from NOAA Coral Reef Watch

    Directory of Open Access Journals (Sweden)

    Gang Liu

    2014-11-01

    Full Text Available The U.S. National Oceanic and Atmospheric Administration (NOAA Coral Reef Watch (CRW program has developed a daily global 5-km product suite based on satellite observations to monitor thermal stress on coral reefs. These products fulfill requests from coral reef managers and researchers for higher resolution products by taking advantage of new satellites, sensors and algorithms. Improvements of the 5-km products over CRW’s heritage global 50-km products are derived from: (1 the higher resolution and greater data density of NOAA’s next-generation operational daily global 5-km geo-polar blended sea surface temperature (SST analysis; and (2 implementation of a new SST climatology derived from the Pathfinder SST climate data record. The new products increase near-shore coverage and now allow direct monitoring of 95% of coral reefs and significantly reduce data gaps caused by cloud cover. The 5-km product suite includes SST Anomaly, Coral Bleaching HotSpots, Degree Heating Weeks and Bleaching Alert Area, matching existing CRW products. When compared with the 50-km products and in situ bleaching observations for 2013–2014, the 5-km products identified known thermal stress events and matched bleaching observations. These near reef-scale products significantly advance the ability of coral reef researchers and managers to monitor coral thermal stress in near-real-time.

  8. Coral reef baselines: how much macroalgae is natural?

    Science.gov (United States)

    Bruno, John F; Precht, William F; Vroom, Peter S; Aronson, Richard B

    2014-03-15

    Identifying the baseline or natural state of an ecosystem is a critical step in effective conservation and restoration. Like most marine ecosystems, coral reefs are being degraded by human activities: corals and fish have declined in abundance and seaweeds, or macroalgae, have become more prevalent. The challenge for resource managers is to reverse these trends, but by how much? Based on surveys of Caribbean reefs in the 1970s, some reef scientists believe that the average cover of seaweed was very low in the natural state: perhaps less than 3%. On the other hand, evidence from remote Pacific reefs, ecological theory, and impacts of over-harvesting in other systems all suggest that, historically, macroalgal biomass may have been higher than assumed. Uncertainties about the natural state of coral reefs illustrate the difficulty of determining the baseline condition of even well studied systems. PMID:24486044

  9. Direct measurements of air-sea CO2 exchange over a coral reef

    Science.gov (United States)

    McGowan, Hamish A.; MacKellar, Mellissa C.; Gray, Michael A.

    2016-05-01

    Quantification of CO2 exchange with the atmosphere over coral reefs has relied on microscale measurements of pCO2 gradients across the air-sea interfacial boundary; shipboard measurements of air-sea CO2 exchange over adjacent ocean inferred to represent over reef processes or ecosystem productivity modeling. Here we present by way of case study the first direct measurements of air-sea CO2 exchange over a coral reef made using the eddy covariance method. Research was conducted during the summer monsoon over a lagoonal platform reef in the southern Great Barrier Reef, Australia. Results show the reef flat to be a net source of CO2 to the atmosphere of similar magnitude as coastal lakes, while adjacent shallow and deep lagoons were net sinks as was the surrounding ocean. This heterogeneity in CO2 exchange with the atmosphere confirms need for spatially representative direct measurements of CO2 over coral reefs to accurately quantify their role in atmospheric carbon budgets.

  10. The economic impact of ocean acidification on coral reefs

    OpenAIRE

    Brander, Luke M.; Rehdanz, Katrin; Tol, Richard S. J.; van Beukering, Pieter J.H.

    2009-01-01

    Because ocean acidification has only recently been recognized as a problem caused by CO2 emissions, impact studies are still rare and estimates of the economic impact are absent. This paper estimates the economic impact of ocean acidification on coral reefs which are generally considered to be economically as well as ecologically important ecosystems. First, we conduct an impact assessment in which atmospheric concentration of CO2 is linked to ocean acidity causing coral reef area loss. Next,...

  11. Microbial responses and coral reef resilience to organic matter inputs

    OpenAIRE

    Garren, Melissa Sara

    2011-01-01

    Little attention has been given to the small-scale mechanisms relevant to microbial processes that determine the resilience of individual corals to the stress of organic matter (OM) inputs. Such mechanisms may be a critical link for predicting larger scale patterns of reef resilience. The research presented here aims to develop methods necessary to elucidate these processes and to explore the in situ responses of microbial assemblages on coral reefs experiencing persistent OM enrichment. A ne...

  12. Predicting Coral Recruitment in Palau’s Complex Reef Archipelago

    OpenAIRE

    Golbuu, Yimnang; Wolanski, Eric; Idechong, Jacques Wasai; Victor, Steven; Isechal, Adelle Lukes; Oldiais, Noelle Wenty; Idip, David; Richmond, Robert H.; van Woesik, Robert

    2012-01-01

    Reproduction and recruitment are key processes that replenish marine populations. Here we use the Palau archipelago, in the western Pacific Ocean, as a case study to examine scales of connectivity and to determine whether an oceanographic model, incorporating the complex reef architecture, is a useful predictor of coral recruitment. We tested the hypothesis that the reefs with the highest retention also had the highest densities of juvenile coral density from 80 field sites. Field comparisons...

  13. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the Coral Sea.

    Directory of Open Access Journals (Sweden)

    Jonathan M Werry

    Full Text Available Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs, vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km³. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs

  14. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the Coral Sea.

    Science.gov (United States)

    Werry, Jonathan M; Planes, Serge; Berumen, Michael L; Lee, Kate A; Braun, Camrin D; Clua, Eric

    2014-01-01

    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km³. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a

  15. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the coral sea

    KAUST Repository

    Werry, Jonathan M.

    2014-01-08

    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km3. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a

  16. Dynamical seasonal prediction of summer sea surface temperatures in the Great Barrier Reef

    Science.gov (United States)

    Spillman, C. M.; Alves, O.

    2009-03-01

    Coral bleaching is a serious problem threatening the world coral reef systems, triggered by high sea surface temperatures (SST) which are becoming more prevalent as a result of global warming. Seasonal forecasts from coupled ocean-atmosphere models can be used to predict anomalous SST months in advance. In this study, we assess the ability of the Australian Bureau of Meteorology seasonal forecast model (POAMA) to forecast SST anomalies in the Great Barrier Reef, Australia, with particular focus on the major 1998 and 2002 bleaching events. Advance warning of potential bleaching events allows for the implementation of management strategies to minimise reef damage. This study represents the first attempt to apply a dynamical seasonal model to the problem of coral bleaching and predict SST over a reef system for up to 6 months lead-time, a potentially invaluable tool for reef managers.

  17. Implications of coral harvest and transplantation on reefs in northwestern Dominica

    OpenAIRE

    Andrew W Bruckner; Eric H Borneman

    2010-01-01

    In June, 2002, the government of Dominica requested assistance in evaluating the coral culture and transplantation activities being undertaken by Oceanographic Institute of Dominica (OID), a coral farm culturing both western Atlantic and Indo-Pacific corals for restoration and commercial sales. We assessed the culture facilities of OID, the condition of reefs, potential impacts of coral collection and benefits of coral transplantation. Coral reefs (9 reefs, 3-20m depth) were characterized by ...

  18. Can we measure beauty? Computational evaluation of coral reef aesthetics

    Science.gov (United States)

    Guibert, Marine; Foerschner, Anja; Co, Tim; Calhoun, Sandi; George, Emma; Hatay, Mark; Dinsdale, Elizabeth; Sandin, Stuart A.; Smith, Jennifer E.; Vermeij, Mark J.A.; Felts, Ben; Dustan, Phillip; Salamon, Peter; Rohwer, Forest

    2015-01-01

    The natural beauty of coral reefs attracts millions of tourists worldwide resulting in substantial revenues for the adjoining economies. Although their visual appearance is a pivotal factor attracting humans to coral reefs current monitoring protocols exclusively target biogeochemical parameters, neglecting changes in their aesthetic appearance. Here we introduce a standardized computational approach to assess coral reef environments based on 109 visual features designed to evaluate the aesthetic appearance of art. The main feature groups include color intensity and diversity of the image, relative size, color, and distribution of discernable objects within the image, and texture. Specific coral reef aesthetic values combining all 109 features were calibrated against an established biogeochemical assessment (NCEAS) using machine learning algorithms. These values were generated for ∼2,100 random photographic images collected from 9 coral reef locations exposed to varying levels of anthropogenic influence across 2 ocean systems. Aesthetic values proved accurate predictors of the NCEAS scores (root mean square error systems this method provides a cost efficient monitoring tool that targets one of the most important socioeconomic values of coral reefs directly tied to revenue for its local population. PMID:26587350

  19. Temperature Regimes Impact Coral Assemblages along Environmental Gradients on Lagoonal Reefs in Belize.

    Science.gov (United States)

    Baumann, Justin H; Townsend, Joseph E; Courtney, Travis A; Aichelman, Hannah E; Davies, Sarah W; Lima, Fernando P; Castillo, Karl D

    2016-01-01

    Coral reefs are increasingly threatened by global and local anthropogenic stressors such as rising seawater temperature, nutrient enrichment, sedimentation, and overfishing. Although many studies have investigated the impacts of local and global stressors on coral reefs, we still do not fully understand how these stressors influence coral community structure, particularly across environmental gradients on a reef system. Here, we investigate coral community composition across three different temperature and productivity regimes along a nearshore-offshore gradient on lagoonal reefs of the Belize Mesoamerican Barrier Reef System (MBRS). A novel metric was developed using ultra-high-resolution satellite-derived estimates of sea surface temperatures (SST) to classify reefs as exposed to low (lowTP), moderate (modTP), or high (highTP) temperature parameters over 10 years (2003 to 2012). Coral species richness, abundance, diversity, density, and percent cover were lower at highTP sites relative to lowTP and modTP sites, but these coral community traits did not differ significantly between lowTP and modTP sites. Analysis of coral life history strategies revealed that highTP sites were dominated by hardy stress-tolerant and fast-growing weedy coral species, while lowTP and modTP sites consisted of competitive, generalist, weedy, and stress-tolerant coral species. Satellite-derived estimates of Chlorophyll-a (chl-a) were obtained for 13-years (2003-2015) as a proxy for primary production. Chl-a concentrations were highest at highTP sites, medial at modTP sites, and lowest at lowTP sites. Notably, thermal parameters correlated better with coral community traits between site types than productivity, suggesting that temperature (specifically number of days above the thermal bleaching threshold) played a greater role in defining coral community structure than productivity on the MBRS. Dominance of weedy and stress-tolerant genera at highTP sites suggests that corals utilizing

  20. EFFECTS OF GLOBAL CHANGE ON CORAL REEF ECOSYSTEMS

    Science.gov (United States)

    Corals and coral reefs of the Caribbean and through the world are deteriorating at an accelerated rate. Several stressors are believed to contrbute to this decline, including global changes in atmospheric gases and land use patterns. In particular, warmer water temperatures and...

  1. Coral reefs as indicators of marine environmental health

    International Nuclear Information System (INIS)

    Coral reefs are one of the most productive and diverse of all ecosystems on the Earth. Although they occupy less than 0.25 percent of the marine environment, the reefs support more than a quarter of all known fish species. They serve as critical habitats for numerous tropical species including reef fishes of ornamental nature and edible fishes. They protect the shores from storms and wave actions

  2. Ocean acidification and warming will lower coral reef resilience

    OpenAIRE

    Anthony, Kenneth R. N.; Maynard, Jeffrey A; Diaz-Pulido, Guillermo; Peter J Mumby; Marshall, Paul A; Cao, Long; Hoegh-Guldberg, Ove

    2011-01-01

    Ocean warming and acidification from increasing levels of atmospheric CO2 represent major global threats to coral reefs, and are in many regions exacerbated by local-scale disturbances such as overfishing and nutrient enrichment. Our understanding of global threats and local-scale disturbances on reefs is growing, but their relative contribution to reef resilience and vulnerability in the future is unclear. Here, we analyse quantitatively how different combinations of CO2 and fishing pressure...

  3. Through bleaching and tsunami : coral reef recovery in the Maldives

    OpenAIRE

    Morri, C.; M. MONTEFALCONE; Lasagna, R.; Gatti, G.; A. Rovere; Parravicini, Valeriano; Baldelli, G.; Colantoni, P.; C.N. BIANCHI

    2015-01-01

    Coral reefs are degrading worldwide, but little information exists on their previous conditions for most regions of the world. Since 1989, we have been studying the Maldives, collecting data before, during and after the bleaching and mass mortality event of 1998. As early as 1999, many newly settled colonies were recorded. Recruits shifted from a dominance of massive and encrusting corals in the early stages of recolonisation towards a dominance of Acropora and Pocillopora by 2009. Coral cove...

  4. Metatranscriptome analysis of the reef-buidling coral Orbicella faveolata indicates holobiont response to coral disease

    OpenAIRE

    Camille eDaniels; Sebastian eBaumgarten; Lauren K Yum; Michell, Craig T.; Till eBayer; Chatchanit eArif; Cornelia eRoder; Ernesto eWeil; Christian Robert Voolstra

    2015-01-01

    White Plague Disease (WPD) is implicated in coral reef decline in the Caribbean and is characterized by microbial community shifts in coral mucus and tissue. Studies thus far have focused on assessing microbial communities or the identification of specific pathogens, yet few have addressed holobiont response across metaorganism compartments in coral disease. Here, we report on the first metatranscriptomic assessment of the coral host, algal symbiont, and microbial compartment in order to surv...

  5. Metatranscriptome analysis of the reef-building coral Orbicella faveolata indicates holobiont response to coral disease

    OpenAIRE

    Daniels, Camille A.; Baumgarten, Sebastian; Lauren K Yum; Michell, Craig T.; Bayer, Till; Arif, Chatchanit; Roder, Cornelia; Weil, Ernesto; Voolstra, Christian R.

    2015-01-01

    White Plague Disease (WPD) is implicated in coral reef decline in the Caribbean and is characterized by microbial community shifts in coral mucus and tissue. Studies thus far have focused on assessing microbial communities or the identification of specific pathogens, yet few have addressed holobiont response across metaorganism compartments in coral disease. Here, we report on the first metatranscriptomic assessment of the coral host, algal symbiont, and microbial compartment in order to surv...

  6. Fifty million years of herbivory on coral reefs: fossils, fish and functional innovations.

    Science.gov (United States)

    Bellwood, D R; Goatley, C H R; Brandl, S J; Bellwood, O

    2014-04-22

    The evolution of ecological processes on coral reefs was examined based on Eocene fossil fishes from Monte Bolca, Italy and extant species from the Great Barrier Reef, Australia. Using ecologically relevant morphological metrics, we investigated the evolution of herbivory in surgeonfishes (Acanthuridae) and rabbitfishes (Siganidae). Eocene and Recent surgeonfishes showed remarkable similarities, with grazers, browsers and even specialized, long-snouted forms having Eocene analogues. These long-snouted Eocene species were probably pair-forming, crevice-feeding forms like their Recent counterparts. Although Eocene surgeonfishes likely played a critical role as herbivores during the origins of modern coral reefs, they lacked the novel morphologies seen in modern Acanthurus and Siganus (including eyes positioned high above their low-set mouths). Today, these forms dominate coral reefs in both abundance and species richness and are associated with feeding on shallow, exposed algal turfs. The radiation of these new forms, and their expansion into new habitats in the Oligocene-Miocene, reflects the second phase in the development of fish herbivory on coral reefs that is closely associated with the exploitation of highly productive short algal turfs. PMID:24573852

  7. Modelling Coral Reef Futures to Inform Management: Can Reducing Local-Scale Stressors Conserve Reefs under Climate Change?

    OpenAIRE

    Gurney, Georgina G.; Melbourne-Thomas, Jessica; Geronimo, Rollan C.; Aliño, Perry M.; Craig R. Johnson

    2013-01-01

    Climate change has emerged as a principal threat to coral reefs, and is expected to exacerbate coral reef degradation caused by more localised stressors. Management of local stressors is widely advocated to bolster coral reef resilience, but the extent to which management of local stressors might affect future trajectories of reef state remains unclear. This is in part because of limited understanding of the cumulative impact of multiple stressors. Models are ideal tools to aid understanding ...

  8. Macroalgal herbivory on recovering versus degrading coral reefs

    Science.gov (United States)

    Chong-Seng, K. M.; Nash, K. L.; Bellwood, D. R.; Graham, N. A. J.

    2014-06-01

    Macroalgal-feeding fishes are considered to be a key functional group on coral reefs due to their role in preventing phase shifts from coral to macroalgal dominance, and potentially reversing the shift should it occur. However, assessments of macroalgal herbivory using bioassay experiments are primarily from systems with relatively high coral cover. This raises the question of whether continued functionality can be ensured in degraded systems. It is clearly important to determine whether the species that remove macroalgae on coral-dominated reefs will still be present and performing significant algal removal on macroalgal-dominated reefs. We compared the identity and effectiveness of macroalgal-feeding fishes on reefs in two conditions post-disturbance—those regenerating with high live coral cover (20-46 %) and those degrading with high macroalgal cover (57-82 %). Using filmed Sargassum bioassays, we found significantly different Sargassum biomass loss between the two conditions; mean assay weight loss due to herbivory was 27.9 ± 4.9 % on coral-dominated reefs and 2.2 ± 1.1 % on reefs with high macroalgal cover. However, once standardised for the availability of macroalgae on the reefs, the rates of removal were similar between the two reef conditions (4.8 ± 4.1 g m-2 h-1 on coral-dominated and 5.3 ± 2.1 g m-2 h-1 on macroalgal-dominated reefs). Interestingly, the Sargassum-assay consumer assemblages differed between reef conditions; nominally grazing herbivores, Siganus puelloides and Chlorurus sordidus, and the browser , Siganus sutor, dominated feeding on high coral cover reefs, whereas browsing herbivores, Naso elegans, Naso unicornis, and Leptoscarus vaigiensis, prevailed on macroalgal-dominated reefs. It appeared that macroalgal density in the surrounding habitat had a strong influence on the species driving the process of macroalgal removal. This suggests that although the function of macroalgal removal may continue, the species responsible may change

  9. Herbicides: A new threat to the Great Barrier Reef

    International Nuclear Information System (INIS)

    The runoff of pesticides (insecticides, herbicides and fungicides) from agricultural lands is a key concern for the health of the iconic Great Barrier Reef, Australia. Relatively low levels of herbicide residues can reduce the productivity of marine plants and corals. However, the risk of these residues to Great Barrier Reef ecosystems has been poorly quantified due to a lack of large-scale datasets. Here we present results of a study tracing pesticide residues from rivers and creeks in three catchment regions to the adjacent marine environment. Several pesticides (mainly herbicides) were detected in both freshwater and coastal marine waters and were attributed to specific land uses in the catchment. Elevated herbicide concentrations were particularly associated with sugar cane cultivation in the adjacent catchment. We demonstrate that herbicides reach the Great Barrier Reef lagoon and may disturb sensitive marine ecosystems already affected by other pressures such as climate change. - Herbicide residues have been detected in Great Barrier Reef catchment waterways and river water plumes which may affect marine ecosystems.

  10. Tradeoffs between fisheries harvest and the resilience of coral reefs.

    Science.gov (United States)

    Bozec, Yves-Marie; O'Farrell, Shay; Bruggemann, J Henrich; Luckhurst, Brian E; Mumby, Peter J

    2016-04-19

    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. PMID:27044106

  11. Baseline Assessment of Coral Reefs in Timor-Leste from 2012 to 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Supported by the U.S. Agency for International Development (USAID), the U.S Department of State, and NOAA's Coral Reef Conservation Program the PIFSC Coral Reef...

  12. Monitoring of Coral Reef Ecosystems on Maui, Hawaii during 1989-1998 (NODC Accession 9900242)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In an effort to detect spatial and temporal changes in the structure of the coral reef community, coral coverage and reef fish density and diversity were documented...

  13. Mechanical vulnerability explains size-dependent mortality of reef corals

    Science.gov (United States)

    Madin, Joshua S; Baird, Andrew H; Dornelas, Maria; Connolly, Sean R

    2014-01-01

    Understanding life history and demographic variation among species within communities is a central ecological goal. Mortality schedules are especially important in ecosystems where disturbance plays a major role in structuring communities, such as coral reefs. Here, we test whether a trait-based, mechanistic model of mechanical vulnerability in corals can explain mortality schedules. Specifically, we ask whether species that become increasingly vulnerable to hydrodynamic dislodgment as they grow have bathtub-shaped mortality curves, whereas species that remain mechanically stable have decreasing mortality rates with size, as predicted by classical life history theory for reef corals. We find that size-dependent mortality is highly consistent between species with the same growth form and that the shape of size-dependent mortality for each growth form can be explained by mechanical vulnerability. Our findings highlight the feasibility of predicting assemblage-scale mortality patterns on coral reefs with trait-based approaches. PMID:24894390

  14. Guam Long-term Coral Reef Monitoring Program Reef Fish Surveys since 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Government of Guam's Long-term Coral Reef Monitoring Program, coordinated by the Guam Coastal Management Program until October 2013 and now coordinated by the...

  15. Climate change and the Great Barrier Reef

    International Nuclear Information System (INIS)

    Full text: Full text: Climate change is now recognised as the greatest long-term threat to the Great Barrier Reef (GBR). Managers face a future in which the impacts of climate change on tropical marine ecosystems are becoming increasingly frequent and severe. Further degradation is inevitable as the climate continues to change but the extent of the decline will depend on the rate and magnitude of climate change and the resilience of the ecosystem. Changes to the ecosystem have implications for the industries and regional communities that depend on the GBR. Climate projections for the GBR region include increasing air and sea temperatures, ocean acidification, nutrient enrichment (via changes in rainfall), altered light levels, more extreme weather events, changes to ocean circulation and sea level rise. Impacts have already been observed, with severe coral bleaching events in 1998 and 2002, and mass mortalities of seabirds linked to anomalously warm summer conditions. Climate change also poses significant threats to the industries and communities that depend on the GBR ecosystem, both directly and indirectly through loss of natural resources; industries such as recreational and commercial fishing, and tourism, which contributes to a regional tourism industry worth $6.1 billion (Access Economics 2005). A vulnerability assessment undertaken by leading experts in climate and marine science identified climate sensitivities for GBR species, habitats, key processes, GBR industries and communities (Johnson and Marshall 2007). This information has been used to develop a Climate Change Action Plan for the GBR. The Action Plan is a five-year program aimed at facilitating targeted science, building a resilient ecosystem, assisting adaptation of industries and communities, and reducing climate footprints. The Action Plan identifies strategies to review current management arrangements and raise awareness of the issue in order to work towards a resilient ecosystem. Integral to

  16. Turning up the Heat: Increasing Temperature and Coral Bleaching at the High Latitude Coral Reefs of the Houtman Abrolhos Islands

    OpenAIRE

    David A Abdo; Bellchambers, Lynda M.; Scott N Evans

    2012-01-01

    BACKGROUND: Coral reefs face increasing pressures particularly when on the edge of their distributions. The Houtman Abrolhos Islands (Abrolhos) are the southernmost coral reef system in the Indian Ocean, and one of the highest latitude reefs in the world. These reefs have a unique mix of tropical and temperate marine fauna and flora and support 184 species of coral, dominated by Acropora species. A significant La Niña event during 2011 produced anomalous conditions of increased temperature al...

  17. Turning up the Heat: Increasing Temperature and Coral Bleaching at the High Latitude Coral Reefs of the Houtman Abrolhos Islands

    OpenAIRE

    Abdo, David A.; Bellchambers, Lynda M.; Evans, Scott N.

    2012-01-01

    Background Coral reefs face increasing pressures particularly when on the edge of their distributions. The Houtman Abrolhos Islands (Abrolhos) are the southernmost coral reef system in the Indian Ocean, and one of the highest latitude reefs in the world. These reefs have a unique mix of tropical and temperate marine fauna and flora and support 184 species of coral, dominated by Acropora species. A significant La Niña event during 2011 produced anomalous conditions of increased temperature alo...

  18. Prioritizing land and sea conservation investments to protect coral reefs.

    Directory of Open Access Journals (Sweden)

    Carissa J Klein

    Full Text Available BACKGROUND: Coral reefs have exceptional biodiversity, support the livelihoods of millions of people, and are threatened by multiple human activities on land (e.g. farming and in the sea (e.g. overfishing. Most conservation efforts occur at local scales and, when effective, can increase the resilience of coral reefs to global threats such as climate change (e.g. warming water and ocean acidification. Limited resources for conservation require that we efficiently prioritize where and how to best sustain coral reef ecosystems. METHODOLOGY/PRINCIPAL FINDINGS: Here we develop the first prioritization approach that can guide regional-scale conservation investments in land- and sea-based conservation actions that cost-effectively mitigate threats to coral reefs, and apply it to the Coral Triangle, an area of significant global attention and funding. Using information on threats to marine ecosystems, effectiveness of management actions at abating threats, and the management and opportunity costs of actions, we calculate the rate of return on investment in two conservation actions in sixteen ecoregions. We discover that marine conservation almost always trumps terrestrial conservation within any ecoregion, but terrestrial conservation in one ecoregion can be a better investment than marine conservation in another. We show how these results could be used to allocate a limited budget for conservation and compare them to priorities based on individual criteria. CONCLUSIONS/SIGNIFICANCE: Previous prioritization approaches do not consider both land and sea-based threats or the socioeconomic costs of conserving coral reefs. A simple and transparent approach like ours is essential to support effective coral reef conservation decisions in a large and diverse region like the Coral Triangle, but can be applied at any scale and to other marine ecosystems.

  19. Water column productivity and temperature predict coral reef regeneration across the Indo-Pacific

    OpenAIRE

    RIEGL, B.; P. W. Glynn; Wieters, E.; S. Purkis; .C. D'Angelo; Wiedenmann, J.

    2015-01-01

    Predicted increases in seawater temperatures accelerate coral reef decline due to mortality by heat-driven coral bleaching. Alteration of the natural nutrient environment of reef corals reduces tolerance of corals to heat and light stress and thus will exacerbate impacts of global warming on reefs. Still, many reefs demonstrate remarkable regeneration from past stress events. This paper investigates the effects of sea surface temperature (SST) and water column productivity on recovery of cora...

  20. Current status, crisis and conservation of coral reef ecosystems in China

    OpenAIRE

    ShaoHong Wu; WenJun Zhang

    2012-01-01

    Harboring rich marine species and playing important ecological functions, coral reef ecosystems have attracted widespread concern around the world. Ecosystem diversity, conservation and management of coral reefs are becoming a hot research area. Coral reefs in China are mainly distributed in the South China Sea and Hainan, Taiwan, Hong Kong, Guangdong, and Guangxi coastal waters. In recent years, due to the global climate change and the growing impact of human activities, coral reef biodivers...

  1. Region-wide temporal and spatial variation in Caribbean reef architecture: is coral cover the whole story?

    OpenAIRE

    Alvarez-Filip, L.; Cote, IM; Gill, JA; Watkinson, AR; Dulvy, NK

    2011-01-01

    The architectural complexity of coral reefs is largely generated by reef-building corals, yet the effects of current regional-scale declines in coral cover on reef complexity are poorly understood. In particular, both the extent to which declines in coral cover lead to declines in complexity and the length of time it takes for reefs to collapse following coral mortality are unknown. Here we assess the extent of temporal and spatial covariation between coral cover and reef architectural comple...

  2. Behaviourally mediated phenotypic selection in a disturbed coral reef environment.

    Directory of Open Access Journals (Sweden)

    Mark I McCormick

    Full Text Available Natural and anthropogenic disturbances are leading to changes in the nature of many habitats globally, and the magnitude and frequency of these perturbations are predicted to increase under climate change. Globally coral reefs are one of the most vulnerable ecosystems to climate change. Fishes often show relatively rapid declines in abundance when corals become stressed and die, but the processes responsible are largely unknown. This study explored the mechanism by which coral bleaching may influence the levels and selective nature of mortality on a juvenile damselfish, Pomacentrus amboinensis, which associates with hard coral. Recently settled fish had a low propensity to migrate small distances (40 cm between habitat patches, even when densities were elevated to their natural maximum. Intraspecific interactions and space use differ among three habitats: live hard coral, bleached coral and dead algal-covered coral. Large fish pushed smaller fish further from the shelter of bleached and dead coral thereby exposing smaller fish to higher mortality than experienced on healthy coral. Small recruits suffered higher mortality than large recruits on bleached and dead coral. Mortality was not size selective on live coral. Survival was 3 times as high on live coral as on either bleached or dead coral. Subtle behavioural interactions between fish and their habitats influence the fundamental link between life history stages, the distribution of phenotypic traits in the local population and potentially the evolution of life history strategies.

  3. The changing dynamics of coral reef science in Arabia.

    Science.gov (United States)

    Vaughan, Grace O; Burt, John A

    2016-04-30

    Six percent of the world's coral reefs occur around the Arabian Peninsula, providing a valuable ecological, economic and scientific resource for the nations bordering its shores. We provide the first region-wide assessment of the current status and historical trends in coral reef research, focusing on research in the Red Sea, Arabian Sea, and Arabian Gulf. In total, 633 regional reef publications have been produced since the 1930s, covering a wide variety of themes and taxa. Our results show a great deal of commonality in regional reef research, but also highlight important differences in research among the various seas as well as knowledge gaps that represent opportunities for future research. A regionally-integrated approach to future research is essential. There is a growing need for large-scale research to guide management of reefs and their stressors, as these operate at much larger scales than the national borders within which most research currently occurs. PMID:26621575

  4. Through bleaching and tsunami: Coral reef recovery in the Maldives.

    Science.gov (United States)

    Morri, Carla; Montefalcone, Monica; Lasagna, Roberta; Gatti, Giulia; Rovere, Alessio; Parravicini, Valeriano; Baldelli, Giuseppe; Colantoni, Paolo; Bianchi, Carlo Nike

    2015-09-15

    Coral reefs are degrading worldwide, but little information exists on their previous conditions for most regions of the world. Since 1989, we have been studying the Maldives, collecting data before, during and after the bleaching and mass mortality event of 1998. As early as 1999, many newly settled colonies were recorded. Recruits shifted from a dominance of massive and encrusting corals in the early stages of recolonisation towards a dominance of Acropora and Pocillopora by 2009. Coral cover, which dropped to less than 10% after the bleaching, returned to pre-bleaching values of around 50% by 2013. The 2004 tsunami had comparatively little effect. In 2014, the coral community was similar to that existing before the bleaching. According to descriptors and metrics adopted, recovery of Maldivian coral reefs took between 6 and 15years, or may even be considered unachieved, as there are species that had not come back yet. PMID:26228070

  5. The exposure of the Great Barrier Reef to ocean acidification.

    Science.gov (United States)

    Mongin, Mathieu; Baird, Mark E; Tilbrook, Bronte; Matear, Richard J; Lenton, Andrew; Herzfeld, Mike; Wild-Allen, Karen; Skerratt, Jenny; Margvelashvili, Nugzar; Robson, Barbara J; Duarte, Carlos M; Gustafsson, Malin S M; Ralph, Peter J; Steven, Andrew D L

    2016-01-01

    The Great Barrier Reef (GBR) is founded on reef-building corals. Corals build their exoskeleton with aragonite, but ocean acidification is lowering the aragonite saturation state of seawater (Ωa). The downscaling of ocean acidification projections from global to GBR scales requires the set of regional drivers controlling Ωa to be resolved. Here we use a regional coupled circulation-biogeochemical model and observations to estimate the Ωa experienced by the 3,581 reefs of the GBR, and to apportion the contributions of the hydrological cycle, regional hydrodynamics and metabolism on Ωa variability. We find more detail, and a greater range (1.43), than previously compiled coarse maps of Ωa of the region (0.4), or in observations (1.0). Most of the variability in Ωa is due to processes upstream of the reef in question. As a result, future decline in Ωa is likely to be steeper on the GBR than currently projected by the IPCC assessment report. PMID:26907171

  6. The exposure of the Great Barrier Reef to ocean acidification

    KAUST Repository

    Mongin, Mathieu

    2016-02-23

    The Great Barrier Reef (GBR) is founded on reef-building corals. Corals build their exoskeleton with aragonite, but ocean acidification is lowering the aragonite saturation state of seawater (Ωa). The downscaling of ocean acidification projections from global to GBR scales requires the set of regional drivers controlling Ωa to be resolved. Here we use a regional coupled circulation–biogeochemical model and observations to estimate the Ωa experienced by the 3,581 reefs of the GBR, and to apportion the contributions of the hydrological cycle, regional hydrodynamics and metabolism on Ωa variability. We find more detail, and a greater range (1.43), than previously compiled coarse maps of Ωa of the region (0.4), or in observations (1.0). Most of the variability in Ωa is due to processes upstream of the reef in question. As a result, future decline in Ωa is likely to be steeper on the GBR than currently projected by the IPCC assessment report.

  7. The Habitat Persistence Hypothesis: A New Perspective on the Distribution of Coral-Reef Organisms

    OpenAIRE

    Pyle, Richard L.; Copus, Joshua M.; Bowen, Brian B.; Kosaki, Randall K.

    2016-01-01

    We propose the “Habitat Persistence Hypothesis” (HPH) to explain patterns of diversity on tropical coral-reefs. We reviewed distributions of organisms inhabiting tropical coral reefs, and formulated the HPH to account for biogeographical patterns on both shallow (<30m) and deep (30–150m) coral-reef habitats. Species occurring on deep reefs appear to show higher rates of endemism and less eastward diversity attenuation than their counterparts on shallow reefs. The HPH stip...

  8. Coral community response to bleaching on a highly disturbed reef.

    Science.gov (United States)

    Guest, J R; Low, J; Tun, K; Wilson, B; Ng, C; Raingeard, D; Ulstrup, K E; Tanzil, J T I; Todd, P A; Toh, T C; McDougald, D; Chou, L M; Steinberg, P D

    2016-01-01

    While many studies of coral bleaching report on broad, regional scale responses, fewer examine variation in susceptibility among coral taxa and changes in community structure, before, during and after bleaching on individual reefs. Here we report in detail on the response to bleaching by a coral community on a highly disturbed reef site south of mainland Singapore before, during and after a major thermal anomaly in 2010. To estimate the capacity for resistance to thermal stress, we report on: a) overall bleaching severity during and after the event, b) differences in bleaching susceptibility among taxa during the event, and c) changes in coral community structure one year before and after bleaching. Approximately two thirds of colonies bleached, however, post-bleaching recovery was quite rapid and, importantly, coral taxa that are usually highly susceptible were relatively unaffected. Although total coral cover declined, there was no significant change in coral taxonomic community structure before and after bleaching. Several factors may have contributed to the overall high resistance of corals at this site including Symbiodinium affiliation, turbidity and heterotrophy. Our results suggest that, despite experiencing chronic anthropogenic disturbances, turbid shallow reef communities may be remarkably resilient to acute thermal stress. PMID:26876092

  9. Stochastic dynamics of a warmer Great Barrier Reef.

    Science.gov (United States)

    Cooper, Jennifer K; Spencer, Matthew; Bruno, John F

    2015-07-01

    Pressure on natural communities from human activities continues to increase. Even unique ecosystems like the Great Barrier Reef (GBR), that until recently were considered near-pristine and well-protected, are showing signs of rapid degradation. We collated recent (1996-2006) spatiotemporal relationships between benthic community composition on the GBR and environmental variables (ocean temperature and local threats resulting from human activity). We built multivariate models of the effects of these variables on short-term dynamics, and developed an analytical approach to study their long-term consequences. We used this approach to study the effects of ocean warming under different levels of local threat. Observed short-term changes in benthic community structure (e.g., declining coral cover) were associated with ocean temperature (warming) and local threats. Our model projected that, in the long-term, coral cover of less than 10% was not implausible. With increasing temperature and/or local threats, corals were initially replaced by sponges, gorgonians, and other taxa, with an eventual moderately high probability of domination (> 50%) by macroalgae when temperature increase was greatest (e.g., 3.5 degrees C of warming). Our approach to modeling community dynamics, based on multivariate statistical models, enabled us to project how environmental change (and thus local and international policy decisions) will influence the future state of coral reefs. The same approach could be applied to other systems for which time series of ecological and environmental variables are available. PMID:26378303

  10. Reef Fishes in Biodiversity Hotspots Are at Greatest Risk from Loss of Coral Species

    OpenAIRE

    Holbrook, Sally J.; Schmitt, Russell J.; Vanessa Messmer; Brooks, Andrew J; Maya Srinivasan; Munday, Philip L.; Jones, Geoffrey P.

    2015-01-01

    Coral reef ecosystems are under a variety of threats from global change and anthropogenic disturbances that are reducing the number and type of coral species on reefs. Coral reefs support upwards of one third of all marine species of fish, so the loss of coral habitat may have substantial consequences to local fish diversity. We posit that the effects of habitat degradation will be most severe in coral regions with highest biodiversity of fishes due to greater specialization by fishes for par...

  11. NOAA's Coral Reef Conservation Program: 2016 Projects Monitoring the Effects of Thermal Stress on Coral Bleaching

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Climate change impacts have been identified as one of the greatest global threats to coral reef ecosystems. As temperature rise, mass bleaching, and infectious...

  12. Guam Long-term Coral Reef Monitoring Program Coral Colony Size and Condition Surveys since 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Government of Guam's Long-term Coral Reef Monitoring Program, coordinated by the Guam Coastal Management Program until October 2013 and now coordinated by the...

  13. Protection, Participation, and Public Awareness : Indonesia Coral Reef Rehabilitation and Management Project

    OpenAIRE

    Kuehnast, Kathleen

    2001-01-01

    The Indonesia Coral Reef Rehabilitation and Management Project (COREMAP) is the first operation supported by the World Bank to focus exclusively on coral reef ecosystems. COREMAP is being implemented in 10 provinces over 15 years, during which period the communities are given incentives, training, and resources to protect the coral reefs. Social Development best practice elements identifie...

  14. 76 FR 24050 - Coral Reef Restoration Plan, Final Programmatic Environmental Impact Statement, Biscayne National...

    Science.gov (United States)

    2011-04-29

    ... National Park Service Coral Reef Restoration Plan, Final Programmatic Environmental Impact Statement... Final Programmatic Environmental Impact Statement for the Coral Reef Restoration Plan, Biscayne National... Impact Statement for the Coral Reef Restoration Plan (Plan/FEIS) for Biscayne National Park, Florida....

  15. 77 FR 48504 - Proposed Information Collection; Comment Request; Economic Value of Puerto Rico's Coral Reef...

    Science.gov (United States)

    2012-08-14

    ... Value of Puerto Rico's Coral Reef Ecosystems for Recreation-Tourism AGENCY: National Oceanic and... values of Puerto Rico's coral reef ecosystems. Estimates will be made for all ecosystem services for the Guanica Bay Watershed and for recreation-tourism for all of Puerto Rico's coral reef ecosystems....

  16. 77 FR 39724 - U.S. Coral Reef Task Force Public Meeting and Public Comment

    Science.gov (United States)

    2012-07-05

    ... Fish and Wildlife Service U.S. Coral Reef Task Force Public Meeting and Public Comment AGENCY: Fish and... U.S. Fish and Wildlife Service (Service), announce a public meeting of the U.S. Coral Reef Task... protect coral reef ecosystems. The Departments of Commerce and the Interior co-chair the USCRTF,...

  17. 75 FR 47624 - U.S. Coral Reef Task Force Public Meeting and Public Comment

    Science.gov (United States)

    2010-08-06

    ... Fish and Wildlife Service U.S. Coral Reef Task Force Public Meeting and Public Comment AGENCY: Fish and... U.S. Fish and Wildlife Service (Service), announce a public meeting of the U.S. Coral Reef Task...: Andrew_Gude@fws.gov ); or Liza Johnson, U.S. Coral Reef Task Force Department of the Interior Liaison,...

  18. 77 FR 6786 - U.S. Coral Reef Task Force Public Meeting and Public Comment

    Science.gov (United States)

    2012-02-09

    ... National Oceanic and Atmospheric Administration U.S. Coral Reef Task Force Public Meeting and Public..., Notice of public comment. SUMMARY: Notice is hereby given of a public meeting of the U.S. Coral Reef Task.... Coral Reef Task Force, provides a forum for coordinated planning and action among federal...

  19. 76 FR 7579 - U.S. Coral Reef Task Force Public Meeting and Public Comment

    Science.gov (United States)

    2011-02-10

    ... Fish and Wildlife Service U.S. Coral Reef Task Force Public Meeting and Public Comment AGENCY: Fish and... U.S. Fish and Wildlife Service (Service), announce a public business meeting of the U.S. Coral Reef...-mail: Andrew_Gude@fws.gov ); or Liza Johnson, U.S. Coral Reef Task Force Department of the...

  20. Assessing the sensitivity of coral reef condition indicators to local and global stressors with Bayesian networks

    Science.gov (United States)

    Coral reefs are highly valued ecosystems that are currently imperiled. Although the value of coral reefs to human societies is only just being investigated and better understood, for many local and global economies coral reefs are important providers of ecosystem services that su...

  1. 77 FR 12567 - Proposed Information Collection; Comment Request; Pacific Islands Region Coral Reef Ecosystems...

    Science.gov (United States)

    2012-03-01

    ... Islands Region Coral Reef Ecosystems Logbook and Reporting AGENCY: National Oceanic and Atmospheric... Special Coral Reef Ecosystem Fishing Permit (authorized under the Fishery Management Plan for Coral Reef Ecosystems of the Western Pacific Region), to complete logbooks and submit them to NMFS. The information...

  2. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    Science.gov (United States)

    Determining stressor-response relationships in reef building corals is a critical need for researchers because of global declines in coral reef ecosystems. A simplified recirculating coral exposure system for laboratory testing of a diversity of species and morphologies of reef b...

  3. Are non-estuarine mangroves connected to coral reefs through fish migration? : A mini-review

    NARCIS (Netherlands)

    Nagelkerken, I.

    2007-01-01

    Mangroves are an important fish habitat, but little is known of their nursery function and connectivity to other habitats such as coral reefs. Here, the present status of knowledge on connectivity between non-estuarine mangroves and coral reefs by postlarval coral reef fishes is reviewed. Only since

  4. 76 FR 77779 - Availability of Seats for the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory...

    Science.gov (United States)

    2011-12-14

    ... Coral Reef Ecosystem Reserve Advisory Council AGENCY: Office of National Marine Sanctuaries (ONMS....byers@noaa.gov . SUPPLEMENTARY INFORMATION: The NWHI Coral Reef Ecosystem Reserve is a ] marine... the following vacant seats on the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve...

  5. 78 FR 49258 - Fisheries in the Western Pacific; Special Coral Reef Ecosystem Fishing Permit

    Science.gov (United States)

    2013-08-13

    ... Coral Reef Ecosystem Fishing Permit AGENCY: National Marine Fisheries Service (NMFS), National Oceanic... assessment; request for comments. SUMMARY: NMFS proposes to issue a Special Coral Reef Ecosystem Fishing Permit that would authorize Kampachi Farms, LLC, to culture and harvest a coral reef ecosystem...

  6. Changes in Biodiversity and Functioning of Reef Fish Assemblages following Coral Bleaching and Coral Loss

    Directory of Open Access Journals (Sweden)

    Nicholas A.J. Graham

    2011-08-01

    Full Text Available Coral reef ecosystems are increasingly subject to severe, large-scale disturbances caused by climate change (e.g., coral bleaching and other more direct anthropogenic impacts. Many of these disturbances cause coral loss and corresponding changes in habitat structure, which has further important effects on abundance and diversity of coral reef fishes. Declines in the abundance and diversity of coral reef fishes are of considerable concern, given the potential loss of ecosystem function. This study explored the effects of coral loss, recorded in studies conducted throughout the world, on the diversity of fishes and also on individual responses of fishes within different functional groups. Extensive (>60% coral loss almost invariably led to declines in fish diversity. Moreover, most fishes declined in abundance following acute disturbances that caused >10% declines in local coral cover. Response diversity, which is considered critical in maintaining ecosystem function and promoting resilience, was very low for corallivores, but was much higher for herbivores, omnivores and carnivores. Sustained and ongoing climate change thus poses a significant threat to coral reef ecosystems and diversity hotspots are no less susceptible to projected changes in diversity and function.

  7. Changes in biodiversity and functioning of reef fish assemblages following coral bleaching and coral loss

    KAUST Repository

    Pratchett, M.S.

    2011-08-12

    Coral reef ecosystems are increasingly subject to severe, large-scale disturbances caused by climate change (e.g., coral bleaching) and other more direct anthropogenic impacts. Many of these disturbances cause coral loss and corresponding changes in habitat structure, which has further important effects on abundance and diversity of coral reef fishes. Declines in the abundance and diversity of coral reef fishes are of considerable concern, given the potential loss of ecosystem function. This study explored the effects of coral loss, recorded in studies conducted throughout the world, on the diversity of fishes and also on individual responses of fishes within different functional groups. Extensive (>60%) coral loss almost invariably led to declines in fish diversity. Moreover, most fishes declined in abundance following acute disturbances that caused >10% declines in local coral cover. Response diversity, which is considered critical in maintaining ecosystem function and promoting resilience, was very low for corallivores, but was much higher for herbivores, omnivores and carnivores. Sustained and ongoing climate change thus poses a significant threat to coral reef ecosystems and diversity hotspots are no less susceptible to projected changes in diversity and function.

  8. Distribution of fish in seagrass, mangroves and coral reefs: life-stage dependent habitat use in Honduras.

    Science.gov (United States)

    Jaxion-Harm, Jessica; Saunders, James; Speight, Martin R

    2012-06-01

    Many coral reef fish exhibit habitat partitioning throughout their lifetimes. Such patterns are evident in the Caribbean where research has been predominantly conducted in the Eastern region. This work addressed the paucity of data regarding Honduran reef fish distribution in three habitat types (seagrass, mangroves, and coral reefs), by surveying fish on the islands of Utila and Cayos Cochinos off the coast of Honduras (part of the Mesoamerican barrier reef). During July 2nd - Aug 27th 2007 and June 22nd - Aug 17th, 2008, visual surveys (SCUBA and snorkel) were performed in belt transects in different areas: eleven coral reef, six seagrass beds, and six mangroves sites. Juvenile densities and total habitat surface area were used to calculate nursery value of seagrass and mangroves. A total of 113 fish species from 32 families were found during underwater surveys. Multi-dimensional analyses revealed distinct clusters of fish communities in each habitat type by separating fish associated with seagrass beds, mangroves, and coral reefs. Coral reefs showed the highest mean fish species richness and were dominated by adult fish, while juvenile fish characterized seagrass beds and mangrove sites. Habitat use differed widely at the fish species level. Scarus iseri (Striped Parrotfish), the most abundant fish in this study, were found in all three habitat types, while Lutjanus apodus (Schoolmaster Snapper) juveniles were located primarily in mangroves before migrating to coral reefs. Many species used seagrass beds and mangroves as nurseries; however, the nursery value could not be generalized at the family level. Furthermore, for some fish species, nursery value varied between islands and sites. Our results suggest that connectivity of seagrass, mangrove, and coral reef sites at a species and site levels, should be taken into consideration when implementing policy and conservation practices. PMID:23894938

  9. Rapid survey protocol that provides dynamic information on reef condition to managers of the Great Barrier Reef.

    Science.gov (United States)

    Beeden, R J; Turner, M A; Dryden, J; Merida, F; Goudkamp, K; Malone, C; Marshall, P A; Birtles, A; Maynard, J A

    2014-12-01

    Managing to support coral reef resilience as the climate changes requires strategic and responsive actions that reduce anthropogenic stress. Managers can only target and tailor these actions if they regularly receive information on system condition and impact severity. In large coral reef areas like the Great Barrier Reef Marine Park (GBRMP), acquiring condition and impact data with good spatial and temporal coverage requires using a large network of observers. Here, we describe the result of ~10 years of evolving and refining participatory monitoring programs used in the GBR that have rangers, tourism operators and members of the public as observers. Participants complete Reef Health and Impact Surveys (RHIS) using a protocol that meets coral reef managers' needs for up-to-date information on the following: benthic community composition, reef condition and impacts including coral diseases, damage, predation and the presence of rubbish. Training programs ensure that the information gathered is sufficiently precise to inform management decisions. Participants regularly report because the demands of the survey methodology have been matched to their time availability. Undertaking the RHIS protocol we describe involves three ~20 min surveys at each site. Participants enter data into an online data management system that can create reports for managers and participants within minutes of data being submitted. Since 2009, 211 participants have completed a total of more than 10,415 surveys at more than 625 different reefs. The two-way exchange of information between managers and participants increases the capacity to manage reefs adaptively, meets education and outreach objectives and can increase stewardship. The general approach used and the survey methodology are both sufficiently adaptable to be used in all reef regions. PMID:25179944

  10. Challenges for Managing Fisheries on Diverse Coral Reefs

    Directory of Open Access Journals (Sweden)

    Douglas Fenner

    2012-03-01

    Full Text Available Widespread coral reef decline has included the decline of reef fish populations, and the subsistence and artisanal fisheries that depend on them. Overfishing and destructive fishing have been identified as the greatest local threats to coral reefs, but the greatest future threats are acidification and increases in mass coral bleaching caused by global warming. Some reefs have shifted from dominance by corals to macroalgae, in what are called “phase shifts”. Depletion of herbivores including fishes has been identified as a contributor to such phase shifts, though nutrients are also involved in complex interactions with herbivory and competition. The depletion of herbivorous fishes implies a reduction of the resilience of coral reefs to the looming threat of mass coral mortality from bleaching, since mass coral deaths are likely to be followed by mass macroalgal blooms on the newly exposed dead substrates. Conventional stock assessment of each fish species would be the preferred option for understanding the status of the reef fishes, but this is far too expensive to be practical because of the high diversity of the fishery and poverty where most reefs are located. In addition, stock assessment models and fisheries in general assume density dependent populations, but a key prediction that stocks recover from fishing is not always confirmed. Catch Per Unit Effort (CPUE has far too many weaknesses to be a useful method. The ratio of catch to stock and the proportion of catch that is mature depend on fish catch data, and are heavily biased toward stocks that are in good condition and incapable of finding species that are in the worst condition. Near-pristine reefs give us a reality check about just how much we have lost. Common fisheries management tools that control effort or catch are often prohibitively difficult to enforce for most coral reefs except in developed countries. Ecosystem-based management requires management of impacts of fishing

  11. Length-weight relationships of coral reef fishes from the Alacran Reef, Yucatan, Mexico

    OpenAIRE

    Gonzalez-Gandara, C.; Perez-Diaz, E.; Santos-Rodriguez, L.; Arias-Gonzalez, J.E.

    2003-01-01

    Length-weight relationships were computed for 42 species of coral reef fishes from 14 families from the Alacran Reef (Yucatan, Mexico). A total of 1 892 individuals was used for this purpose. The fish species were caught by different fishing techniques such as fishhooks, harpoons, gill and trawl nets. The sampling period was from March 1998 to January 2000.

  12. Climate-driven coral reorganisation influences aggressive behaviour in juvenile coral-reef fishes

    OpenAIRE

    Kok, Judith E.; Graham, Nicholas Anthony James; Hoogenboom, Mia O.

    2016-01-01

    Globally, habitat degradation is altering the abundance and diversity of species in a variety of ecosystems. This study aimed to determine how habitat degradation, in terms of changing coral composition under climate change, affected abundance, species richness and aggressive behaviour of juveniles of three damselfishes (Pomacentrus moluccensis, P. amboinensis and Dischistodus perspicillatus, in order of decreasing reliance on coral). Patch reefs were constructed to simulate two types of reef...

  13. Sewage pollution: mitigation is key for coral reef stewardship.

    Science.gov (United States)

    Wear, Stephanie L; Thurber, Rebecca Vega

    2015-10-01

    Coral reefs are in decline worldwide, and land-derived sources of pollution, including sewage, are a major force driving that deterioration. This review presents evidence that sewage discharge occurs in waters surrounding at least 104 of 112 reef geographies. Studies often refer to sewage as a single stressor. However, we show that it is more accurately characterized as a multiple stressor. Many of the individual agents found within sewage, specifically freshwater, inorganic nutrients, pathogens, endocrine disrupters, suspended solids, sediments, and heavy metals, can severely impair coral growth and/or reproduction. These components of sewage may interact with each other to create as-yet poorly understood synergisms (e.g., nutrients facilitate pathogen growth), and escalate impacts of other, non-sewage-based stressors. Surprisingly few published studies have examined impacts of sewage in the field, but those that have suggest negative effects on coral reefs. Because sewage discharge proximal to sensitive coral reefs is widespread across the tropics, it is imperative for coral reef-focused institutions to increase investment in threat-abatement strategies for mitigating sewage pollution. PMID:25959987

  14. Energetic differences between bacterioplankton trophic groups and coral reef resistance.

    Science.gov (United States)

    McDole Somera, Tracey; Bailey, Barbara; Barott, Katie; Grasis, Juris; Hatay, Mark; Hilton, Brett J; Hisakawa, Nao; Nosrat, Bahador; Nulton, James; Silveira, Cynthia B; Sullivan, Chris; Brainard, Russell E; Rohwer, Forest

    2016-04-27

    Coral reefs are among the most productive and diverse marine ecosystems on the Earth. They are also particularly sensitive to changing energetic requirements by different trophic levels. Microbialization specifically refers to the increase in the energetic metabolic demands of microbes relative to macrobes and is significantly correlated with increasing human influence on coral reefs. In this study, metabolic theory of ecology is used to quantify the relative contributions of two broad bacterioplankton groups, autotrophs and heterotrophs, to energy flux on 27 Pacific coral reef ecosystems experiencing human impact to varying degrees. The effective activation energy required for photosynthesis is lower than the average energy of activation for the biochemical reactions of the Krebs cycle, and changes in the proportional abundance of these two groups can greatly affect rates of energy and materials cycling. We show that reef-water communities with a higher proportional abundance of microbial autotrophs expend more metabolic energy per gram of microbial biomass. Increased energy and materials flux through fast energy channels (i.e. water-column associated microbial autotrophs) may dampen the detrimental effects of increased heterotrophic loads (e.g. coral disease) on coral reef systems experiencing anthropogenic disturbance. PMID:27097927

  15. The importance of structural complexity in coral reef ecosystems

    Science.gov (United States)

    Graham, N. A. J.; Nash, K. L.

    2013-06-01

    The importance of structural complexity in coral reefs has come to the fore with the global degradation of reef condition; however, the limited scale and replication of many studies have restricted our understanding of the role of complexity in the ecosystem. We qualitatively and quantitatively (where sufficient standardised data were available) assess the literature regarding the role of structural complexity in coral reef ecosystems. A rapidly increasing number of publications have studied the role of complexity in reef ecosystems over the past four decades, with a concomitant increase in the diversity of methods used to quantify structure. Quantitative analyses of existing data indicate a strong negative relationship between structural complexity and algal cover, which may reflect the important role complexity plays in enhancing herbivory by reef fishes. The cover of total live coral and branching coral was positively correlated with structural complexity. These habitat attributes may be creating much of the structure, resulting in a collinear relationship; however, there is also evidence of enhanced coral recovery from disturbances where structural complexity is high. Urchin densities were negatively correlated with structural complexity; a relationship that may be driven by urchins eroding reef structure or by their gregarious behaviour when in open space. There was a strong positive relationship between structural complexity and fish density and biomass, likely mediated through density-dependent competition and refuge from predation. More variable responses were found when assessing individual fish families, with all families examined displaying a positive relationship to structural complexity, but only half of these relationships were significant. Although only corroborated with qualitative data, structural complexity also seems to have a positive effect on two ecosystem services: tourism and shoreline protection. Clearly, structural complexity is an

  16. Macroalgae in the coral reefs of Eilat (Gulf of Aqaba, Red Sea) as a possible indicator of reef degradation

    International Nuclear Information System (INIS)

    The current state of health of the coral reefs in the northern Gulf of Aqaba (Red Sea), notably the Eilat reefs, is under debate regarding both their exact condition and the causes of degradation. A dearth of earlier data and unequivocal reliable indices are the major problems hinder a clear understanding of the reef state. Our research objective was to examine coral-algal dynamics as a potential cause and an indication of reef degradation. The community structure of stony corals and algae along the northern Gulf of Aqaba reveal non-seasonal turf algae dominancy in the shallow Eilat reefs (up to 72%), while the proximate Aqaba reefs present negligible turf cover (<6%). We believe that turf dominancy can indicate degradation in these reefs, based on the reduction in essential reef components followed by proliferation of perennial turf algae. Our findings provide further evidence for the severe state of the Eilat coral reefs.

  17. Resilience of coral reefs in the main Hawaiian Islands from 2013 to 2014 (NCEI Accession 0128219)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Declining health of coral reef ecosystems led scientists to search for factors that support reef resilience: the ability of reefs to resist and recover from...

  18. Coral and artificial reef shape files, Broward County, Florida, (NODC Accession 0000244)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Coral reef and artificial reef location shape files and accompanying table files for reefs located off shore of Broward County, Florida. Accompanying "attribute"...

  19. Florida Integrated Science Center (FISC) Coral Reef Research

    Science.gov (United States)

    Poore, D.Z.

    2008-01-01

    Coral reefs provide important ecosystem services such as shoreline protection and the support of lucrative industries including fisheries and tourism. Such ecosystem services are being compromised as reefs decline due to coral disease, climate change, overfishing, and pollution. There is a need for focused, integrated science to understand the complex ecological interactions and effects of these many stressors and to provide information that will effectively guide policies and best management practices to preserve and restore these important resources. The U.S. Geological Survey Florida Integrated Science Center (USGS-FISC) is conducting a coordinated Coral Reef Research Project beginning in 2009. Specific research topics are aimed at addressing priorities identified in the 'Strategic Science for Coral Ecosystems 2007-2011' document (U.S. Geological Survey, 2007). Planned research will include a blend of historical, monitoring, and process studies aimed at improving our understanding of the development, current status and function, and likely future changes in coral ecosystems. Topics such as habitat characterization and distribution, coral disease, and trends in biogenic calcification are major themes of understanding reef structure, ecological integrity, and responses to global change.

  20. ReefBase - a global database of coral reef systems and their resources

    OpenAIRE

    McManus, J

    1994-01-01

    ReefBase a global database of coral reefs systems and their resources was initiated at International Center for Living Aquatic Resources Management (ICLARM), Philippines in November 1993. The CEC has provided funding for the first two years and the database was developed in collaboration with the World Conservation Monitoring Centre in Cambridge, UK, as well as other national, regional, and international institutions. The ReefBase project activities and what ICLARM will do to accomplish the p...

  1. Water column productivity and temperature predict coral reef regeneration across the Indo-Pacific

    Science.gov (United States)

    Riegl, B.; Glynn, P. W.; Wieters, E.; Purkis, S.; D'Angelo, C.; Wiedenmann, J.

    2015-02-01

    Predicted increases in seawater temperatures accelerate coral reef decline due to mortality by heat-driven coral bleaching. Alteration of the natural nutrient environment of reef corals reduces tolerance of corals to heat and light stress and thus will exacerbate impacts of global warming on reefs. Still, many reefs demonstrate remarkable regeneration from past stress events. This paper investigates the effects of sea surface temperature (SST) and water column productivity on recovery of coral reefs. In 71 Indo-Pacific sites, coral cover changes over the past 1-3 decades correlated negative-exponentially with mean SST, chlorophyll a, and SST rise. At six monitoring sites (Persian/Arabian Gulf, Red Sea, northern and southern Galápagos, Easter Island, Panama), over half of all corals were coral reefs presently have the best chances for survival. However, reefs best buffered against temperature and nutrient effects are those that current studies suggest to be most at peril from future ocean acidification.

  2. Growth study of branching coral Acropora formosa between natural reef habitats and in situ coral nurseries

    Science.gov (United States)

    Xin, Loke Hai; Hyde, Julian; Cob, Zaidi Che; Adzis, Kee Alfian Abdul

    2013-11-01

    Being a common reef building coral in Malaysian waters, growth of Acropora Formosa in natural reef habitat and coral nursery condition had been studied in aspects of extension growth, survival and proto-branch generation. The study sites took place at two separate islands with different environment conditions. In this study, A. formosa samples of natural reefs at Pangkor Island turbid waters recorded better growth in average extension rate (0.71 ±0.48 cm/month) and higher proto-branch generation rate (up to 52% after 6 months) than Tioman Island samples (0.38 ±0.34 cm/month, highest 17% after 6 months). However, Tioman Island natural reef samples maintained 100% survival throughout the study period. Then, branch fragments or nubbins of A. formosa were transplanted into two coral nursery sites at Tioman Island. Among these two coral nurseries, the Tekek site had better growth in all three aspects than Air Batang site. This was believed due to Tekek nursery had been setup with nubbins for more than 6 months before Air Batang nursery, thus the Tekek samples were conditioned long enough for growing in the coral nursery environment. The results of this study documented the growth of this particular coral species in two islands of Peninsular Malaysia, and demonstrated the potential application of A. Formosa for coral transplant, in situ nursery and active reef restoration.

  3. Scientific Frontiers in the Management of Coral Reefs

    Directory of Open Access Journals (Sweden)

    Shankar eAswani

    2015-07-01

    Full Text Available Coral reefs are subjected globally to a variety of natural and anthropogenic stressors that often act synergistically. Today, reversing ongoing and future coral reef degradation presents significant challenges and countering this negative trend will take considerable efforts and investments. Scientific knowledge can inform and guide the requisite decision-making process and offer practical solutions to the problem of protection as the effects of climate change exacerbate. However, implementation of solutions presently lags far behind the pace required to reverse global declines, and there is a need for an urgent and significant step-up in the extent and range of strategies being implemented. In this paper, we consider scientific frontiers in natural and social science research that can help build stronger support for reef management and improve the efficacy of interventions. We cover various areas including: (1 enhancing the case for reef conservation and management, (2 dealing with local stressors on reefs, (3 addressing global climate change impacts, (4 and reviewing various approaches to the governance of coral reefs. In sum, we consider scientific frontiers in natural and social science that will require further attention in coming years as managers’ work towards building stronger support for reef management and improve the efficacy of local interventions.

  4. The diversity of coral reefs: what are we missing?

    Directory of Open Access Journals (Sweden)

    Laetitia Plaisance

    Full Text Available Tropical reefs shelter one quarter to one third of all marine species but one third of the coral species that construct reefs are now at risk of extinction. Because traditional methods for assessing reef diversity are extremely time consuming, taxonomic expertise for many groups is lacking, and marine organisms are thought to be less vulnerable to extinction, most discussions of reef conservation focus on maintenance of ecosystem services rather than biodiversity loss. In this study involving the three major oceans with reef growth, we provide new biodiversity estimates based on quantitative sampling and DNA barcoding. We focus on crustaceans, which are the second most diverse group of marine metazoans. We show exceptionally high numbers of crustacean species associated with coral reefs relative to sampling effort (525 species from a combined, globally distributed sample area of 6.3 m(2. The high prevalence of rare species (38% encountered only once, the low level of spatial overlap (81% found in only one locality and the biogeographic patterns of diversity detected (Indo-West Pacific>Central Pacific>Caribbean are consistent with results from traditional survey methods, making this approach a reliable and efficient method for assessing and monitoring biodiversity. The finding of such large numbers of species in a small total area suggests that coral reef diversity is seriously under-detected using traditional survey methods, and by implication, underestimated.

  5. A modeling tool to evaluate regional coral reef responses to changes in climate and ocean chemistry

    Science.gov (United States)

    Buddemeier, R.W.; Jokiel, P.L.; Zimmerman, K.M.; Lane, D.R.; Carey, J.M.; Bohling, G.C.; Martinich, J.A.

    2008-01-01

    We developed a spreadsheet-based model for the use of managers, conservationists, and biologists for projecting the effects of climate change on coral reefs at local-to-regional scales. The COMBO (Coral Mortality and Bleaching Output) model calculates the impacts to coral reefs from changes in average SST and CO2 concentrations, and from high temperature mortality (bleaching) events. The model uses a probabilistic assessment of the frequency of high temperature events under a future climate to address scientific uncertainties about potential adverse effects. COMBO offers data libraries and default factors for three selected regions (Hawai'i, Great Barrier Reef, and Caribbean), but it is structured with user-selectable parameter values and data input options, making possible modifications to reflect local conditions or to incorporate local expertise. Preliminary results from sensitivity analyses and simulation examples for Hawai'i demonstrate the relative importance of high temperature events, increased average temperature, and increased CO2 concentration on the future status of coral reefs; Illustrate significant interactions among variables; and allow comparisons of past environmental history with future predictions. ?? 2008, by the American Society of Limnology and Oceanugraphy, Inc.

  6. Temporal clustering of tropical cyclones on the Great Barrier Reef and its ecological importance

    Science.gov (United States)

    Wolff, Nicholas H.; Wong, Aaron; Vitolo, Renato; Stolberg, Kristin; Anthony, Kenneth R. N.; Mumby, Peter J.

    2016-06-01

    Tropical cyclones have been a major cause of reef coral decline during recent decades, including on the Great Barrier Reef (GBR). While cyclones are a natural element of the disturbance regime of coral reefs, the role of temporal clustering has previously been overlooked. Here, we examine the consequences of different types of cyclone temporal distributions (clustered, stochastic or regular) on reef ecosystems. We subdivided the GBR into 14 adjoining regions, each spanning roughly 300 km, and quantified both the rate and clustering of cyclones using dispersion statistics. To interpret the consequences of such cyclone variability for coral reef health, we used a model of observed coral population dynamics. Results showed that clustering occurs on the margins of the cyclone belt, being strongest in the southern reefs and the far northern GBR, which also has the lowest cyclone rate. In the central GBR, where rates were greatest, cyclones had a relatively regular temporal pattern. Modelled dynamics of the dominant coral genus, Acropora, suggest that the long-term average cover might be more than 13 % greater (in absolute cover units) under a clustered cyclone regime compared to stochastic or regular regimes. Thus, not only does cyclone clustering vary significantly along the GBR but such clustering is predicted to have a marked, and management-relevant, impact on the status of coral populations. Additionally, we use our regional clustering and rate results to sample from a library of over 7000 synthetic cyclone tracks for the GBR. This allowed us to provide robust reef-scale maps of annual cyclone frequency and cyclone impacts on Acropora. We conclude that assessments of coral reef vulnerability need to account for both spatial and temporal cyclone distributions.

  7. High macroalgal cover and low coral recruitment undermines the potential resilience of the world's southernmost coral reef assemblages

    KAUST Repository

    Hoey, Andrew

    2011-10-03

    Coral reefs are under increasing pressure from anthropogenic and climate-induced stressors. The ability of reefs to reassemble and regenerate after disturbances (i.e., resilience) is largely dependent on the capacity of herbivores to prevent macroalgal expansion, and the replenishment of coral populations through larval recruitment. Currently there is a paucity of this information for higher latitude, subtropical reefs. To assess the potential resilience of the benthic reef assemblages of Lord Howe Island (31°32?S, 159°04?E), the worlds\\' southernmost coral reef, we quantified the benthic composition, densities of juvenile corals (as a proxy for coral recruitment), and herbivorous fish communities. Despite some variation among habitats and sites, benthic communities were dominated by live scleractinian corals (mean cover 37.4%) and fleshy macroalgae (20.9%). Live coral cover was higher than in most other subtropical reefs and directly comparable to lower latitude tropical reefs. Juvenile coral densities (0.8 ind.m -2), however, were 5-200 times lower than those reported for tropical reefs. Overall, macroalgal cover was negatively related to the cover of live coral and the density of juvenile corals, but displayed no relationship with herbivorous fish biomass. The biomass of herbivorous fishes was relatively low (204 kg.ha -1), and in marked contrast to tropical reefs was dominated by macroalgal browsing species (84.1%) with relatively few grazing species. Despite their extremely low biomass, grazing fishes were positively related to both the density of juvenile corals and the cover of bare substrata, suggesting that they may enhance the recruitment of corals through the provision of suitable settlement sites. Although Lord Howe Islands\\' reefs are currently coral-dominated, the high macroalgal cover, coupled with limited coral recruitment and low coral growth rates suggest these reefs may be extremely susceptible to future disturbances. © 2011 Hoey et al.

  8. High macroalgal cover and low coral recruitment undermines the potential resilience of the world's southernmost coral reef assemblages.

    Directory of Open Access Journals (Sweden)

    Andrew S Hoey

    Full Text Available Coral reefs are under increasing pressure from anthropogenic and climate-induced stressors. The ability of reefs to reassemble and regenerate after disturbances (i.e., resilience is largely dependent on the capacity of herbivores to prevent macroalgal expansion, and the replenishment of coral populations through larval recruitment. Currently there is a paucity of this information for higher latitude, subtropical reefs. To assess the potential resilience of the benthic reef assemblages of Lord Howe Island (31°32'S, 159°04'E, the worlds' southernmost coral reef, we quantified the benthic composition, densities of juvenile corals (as a proxy for coral recruitment, and herbivorous fish communities. Despite some variation among habitats and sites, benthic communities were dominated by live scleractinian corals (mean cover 37.4% and fleshy macroalgae (20.9%. Live coral cover was higher than in most other subtropical reefs and directly comparable to lower latitude tropical reefs. Juvenile coral densities (0.8 ind.m(-2, however, were 5-200 times lower than those reported for tropical reefs. Overall, macroalgal cover was negatively related to the cover of live coral and the density of juvenile corals, but displayed no relationship with herbivorous fish biomass. The biomass of herbivorous fishes was relatively low (204 kg.ha(-1, and in marked contrast to tropical reefs was dominated by macroalgal browsing species (84.1% with relatively few grazing species. Despite their extremely low biomass, grazing fishes were positively related to both the density of juvenile corals and the cover of bare substrata, suggesting that they may enhance the recruitment of corals through the provision of suitable settlement sites. Although Lord Howe Islands' reefs are currently coral-dominated, the high macroalgal cover, coupled with limited coral recruitment and low coral growth rates suggest these reefs may be extremely susceptible to future disturbances.

  9. Hysteresis in coral reefs under macroalgal toxicity and overfishing.

    Science.gov (United States)

    Bhattacharyya, Joydeb; Pal, Samares

    2015-03-01

    Macroalgae and corals compete for the available space in coral reef ecosystems.While herbivorous reef fish play a beneficial role in decreasing the growth of macroalgae, macroalgal toxicity and overfishing of herbivores leads to proliferation of macroalgae. The abundance of macroalgae changes the community structure towards a macroalgae-dominated reef ecosystem. We investigate coral-macroalgal phase shifts by means of a continuous time model in a food chain. Conditions for local asymptotic stability of steady states are derived. It is observed that in the presence of macroalgal toxicity and overfishing, the system exhibits hysteresis through saddle-node bifurcation and transcritical bifurcation. We examine the effects of time lags in the liberation of toxins by macroalgae and the recovery of algal turf in response to grazing of herbivores on macroalgae by performing equilibrium and stability analyses of delay-differential forms of the ODE model. Computer simulations have been carried out to illustrate the different analytical results. PMID:25708511

  10. A Fundamental Paradigm for Coral Reef Carbonate Sediment Dissolution

    Directory of Open Access Journals (Sweden)

    Andreas J Andersson

    2015-07-01

    Full Text Available The long-term success of coral reefs depends on a positive balance of calcium carbonate production exceeding dissolution, erosion, and material export. As a result of ocean acidification, coral reefs could transition from net accretion to net erosion owing to decreasing rates of calcification and increasing rates of chemical dissolution and bioerosion. Here, I present a fundamental paradigm that aims to explain the main driver of carbonate sediment dissolution on coral reefs based on theory and a new empirical dataset of pore water carbonate chemistry from the Bermuda coral reef platform. The paradigm shows that carbonate sediment dissolution is most strongly controlled by the extent of organic matter decomposition in the sediments, but that the magnitude of dissolution is influenced by how much decomposition is required to reach pore water undersaturation with respect to the most soluble bulk carbonate mineral phase present in the sediments, a condition defined as the Carbonate Critical Threshold (CCT. Decomposition of organic matter beyond the CCT under aerobic conditions results in stoichiometric proportional dissolution of carbonate sediments. As ocean acidification proceeds over the next several decades, the extent of organic matter decomposition required to reach the CCT will decrease, carbonate dissolution will increase, and subsequently the accumulation of carbonate sediments will decrease. Since drastic reductions in anthropogenic CO2 emission are unlikely in the foreseeable future, the paradigm shows that active controls and reduction of organic matter input to coral reefs at the local scale might be an effective mitigation strategy to prevent or delay coral reefs transitioning to a state of net dissolution.

  11. A morphometric assessment and classification of coral reef spur and groove morphology

    Science.gov (United States)

    Duce, S.; Vila-Concejo, A.; Hamylton, S. M.; Webster, J. M.; Bruce, E.; Beaman, R. J.

    2016-07-01

    Spurs and grooves (SaGs) are a common and important feature of coral reef fore slopes worldwide. However, they are difficult to access and hence their morphodynamics and formation are poorly understood. We use remote sensing, with extensive ground truthing, to measure SaG morphometrics and environmental factors at 11,430 grooves across 17 reefs in the southern Great Barrier Reef, Australia. We revealed strong positive correlations between groove length, orientation and wave exposure with longer, more closely-spaced grooves oriented easterly reflecting the dominant swell regime. Wave exposure was found to be the most important factor controlling SaG distribution and morphology. Gradient of the upper reef slope was also an important limiting factor, with SaGs less likely to develop in steeply sloping (> 5°) areas. We used a subset of the morphometric data (11 reefs) to statistically define four classes of SaG. This classification scheme was tested on the remaining six reefs. SaGs in the four classes differ in morphology, groove substrate and coral cover. These differences provide insights into SaG formation mechanisms with implications to reef platform growth and evolution. We hypothesize SaG formation is dominated by coral growth processes at two classes and erosion processes at one class. A fourth class may represent relic features formed earlier in the Holocene transgression. The classes are comparable with SaGs elsewhere, suggesting the classification could be applied globally with the addition of new classes if necessary. While further research is required, we show remotely sensed SaG morphometrics can provide useful insights into reef platform evolution.

  12. Fish-derived nutrient hotspots shape coral reef benthic communities.

    Science.gov (United States)

    Shantz, Andrew A; Ladd, Mark C; Schrack, Elizabeth; Burkepile, Deron E

    2015-12-01

    Animal-derived nutrients play an important role in structuring nutrient regimes within and between ecosystems. When animals undergo repetitive, aggregating behavior through time, they can create nutrient hotspots where rates of biogeochemical activity are higher than those found in the surrounding environment. In turn, these hotspots can influence ecosystem processes and community structure. We examined the potential for reef fishes from the family Haemulidae (grunts) to create nutrient hotspots and the potential impact of these hotspots on reef communities. To do so, we tracked the schooling locations of diurnally migrating grunts, which shelter at reef sites during the day but forage off reef each night, and measured the impact of these fish schools on benthic communities. We found that grunt schools showed a high degree of site fidelity, repeatedly returning to the same coral heads. These aggregations created nutrient hotspots around coral heads where nitrogen and phosphorus delivery was roughly 10 and 7 times the respective rates of delivery to structurally similar sites that lacked schools of these fishes. In turn, grazing rates of herbivorous fishes at grunt-derived hotspots were approximately 3 times those of sites where grunts were rare. These differences in nutrient delivery and grazing led to distinct benthic communities with higher cover of crustose coralline algae and less total algal abundance at grunt aggregation sites. Importantly, coral growth was roughly 1.5 times greater at grunt hotspots, likely due to the important nutrient subsidy. Our results suggest that schooling reef fish and their nutrient subsidies play an important role in mediating community structure on coral reefs and that overfishing may have important negative consequences on ecosystem functions. As such, management strategies must consider mesopredatory fishes in addition to current protection often offered to herbivores and top-tier predators. Furthermore, our results suggest that

  13. Reversal of ocean acidification enhances net coral reef calcification

    Science.gov (United States)

    Albright, Rebecca; Caldeira, Lilian; Hosfelt, Jessica; Kwiatkowski, Lester; MacLaren, Jana K.; Mason, Benjamin M.; Nebuchina, Yana; Ninokawa, Aaron; Pongratz, Julia; Ricke, Katharine L.; Rivlin, Tanya; Schneider, Kenneth; Sesboüé, Marine; Shamberger, Kathryn; Silverman, Jacob; Wolfe, Kennedy; Zhu, Kai; Caldeira, Ken

    2016-03-01

    Approximately one-quarter of the anthropogenic carbon dioxide released into the atmosphere each year is absorbed by the global oceans, causing measurable declines in surface ocean pH, carbonate ion concentration ([CO32‑]), and saturation state of carbonate minerals (Ω). This process, referred to as ocean acidification, represents a major threat to marine ecosystems, in particular marine calcifiers such as oysters, crabs, and corals. Laboratory and field studies have shown that calcification rates of many organisms decrease with declining pH, [CO32‑], and Ω. Coral reefs are widely regarded as one of the most vulnerable marine ecosystems to ocean acidification, in part because the very architecture of the ecosystem is reliant on carbonate-secreting organisms. Acidification-induced reductions in calcification are projected to shift coral reefs from a state of net accretion to one of net dissolution this century. While retrospective studies show large-scale declines in coral, and community, calcification over recent decades, determining the contribution of ocean acidification to these changes is difficult, if not impossible, owing to the confounding effects of other environmental factors such as temperature. Here we quantify the net calcification response of a coral reef flat to alkalinity enrichment, and show that, when ocean chemistry is restored closer to pre-industrial conditions, net community calcification increases. In providing results from the first seawater chemistry manipulation experiment of a natural coral reef community, we provide evidence that net community calcification is depressed compared with values expected for pre-industrial conditions, indicating that ocean acidification may already be impairing coral reef growth.

  14. Reversal of ocean acidification enhances net coral reef calcification.

    Science.gov (United States)

    Albright, Rebecca; Caldeira, Lilian; Hosfelt, Jessica; Kwiatkowski, Lester; Maclaren, Jana K; Mason, Benjamin M; Nebuchina, Yana; Ninokawa, Aaron; Pongratz, Julia; Ricke, Katharine L; Rivlin, Tanya; Schneider, Kenneth; Sesboüé, Marine; Shamberger, Kathryn; Silverman, Jacob; Wolfe, Kennedy; Zhu, Kai; Caldeira, Ken

    2016-03-17

    Approximately one-quarter of the anthropogenic carbon dioxide released into the atmosphere each year is absorbed by the global oceans, causing measurable declines in surface ocean pH, carbonate ion concentration ([CO3(2-)]), and saturation state of carbonate minerals (Ω). This process, referred to as ocean acidification, represents a major threat to marine ecosystems, in particular marine calcifiers such as oysters, crabs, and corals. Laboratory and field studies have shown that calcification rates of many organisms decrease with declining pH, [CO3(2-)], and Ω. Coral reefs are widely regarded as one of the most vulnerable marine ecosystems to ocean acidification, in part because the very architecture of the ecosystem is reliant on carbonate-secreting organisms. Acidification-induced reductions in calcification are projected to shift coral reefs from a state of net accretion to one of net dissolution this century. While retrospective studies show large-scale declines in coral, and community, calcification over recent decades, determining the contribution of ocean acidification to these changes is difficult, if not impossible, owing to the confounding effects of other environmental factors such as temperature. Here we quantify the net calcification response of a coral reef flat to alkalinity enrichment, and show that, when ocean chemistry is restored closer to pre-industrial conditions, net community calcification increases. In providing results from the first seawater chemistry manipulation experiment of a natural coral reef community, we provide evidence that net community calcification is depressed compared with values expected for pre-industrial conditions, indicating that ocean acidification may already be impairing coral reef growth. PMID:26909578

  15. Isolation by resistance across a complex coral reef seascape.

    Science.gov (United States)

    Thomas, Luke; Kennington, W Jason; Stat, Michael; Wilkinson, Shaun P; Kool, Johnathan T; Kendrick, Gary A

    2015-08-01

    A detailed understanding of the genetic structure of populations and an accurate interpretation of processes driving contemporary patterns of gene flow are fundamental to successful spatial conservation management. The field of seascape genetics seeks to incorporate environmental variables and processes into analyses of population genetic data to improve our understanding of forces driving genetic divergence in the marine environment. Information about barriers to gene flow (such as ocean currents) is used to define a resistance surface to predict the spatial genetic structure of populations and explain deviations from the widely applied isolation-by-distance model. The majority of seascape approaches to date have been applied to linear coastal systems or at large spatial scales (more than 250 km), with very few applied to complex systems at regional spatial scales (less than 100 km). Here, we apply a seascape genetics approach to a peripheral population of the broadcast-spawning coral Acropora spicifera across the Houtman Abrolhos Islands, a high-latitude complex coral reef system off the central coast of Western Australia. We coupled population genetic data from a panel of microsatellite DNA markers with a biophysical dispersal model to test whether oceanographic processes could explain patterns of genetic divergence. We identified significant variation in allele frequencies over distances of less than 10 km, with significant differentiation occurring between adjacent sites but not between the most geographically distant ones. Recruitment probabilities between sites based on simulated larval dispersal were projected into a measure of resistance to connectivity that was significantly correlated with patterns of genetic divergence, demonstrating that patterns of spatial genetic structure are a function of restrictions to gene flow imposed by oceanographic currents. This study advances our understanding of the role of larval dispersal on the fine-scale genetic

  16. African dust and the demise of Caribbean Coral Reefs

    Science.gov (United States)

    Shinn, Eugene A.; Smith, Garriet W.; Prospero, Joseph M.; Betzer, Peter; Hayes, Marshall L.; Garrison, Virginia; Barber, Richard T.

    2000-10-01

    The vitality of Caribbean coral reefs has undergone a continual state of decline since the late 1970s, a period of time coincidental with large increases in transatlantic dust transport. It is proposed that the hundreds of millions of tons/year of soil dust that have been crossing the Atlantic during the last 25 years could be a significant contributor to coral reef decline and may be affecting other ecosystems. Benchmark events, such as near synchronous Caribbean-wide mortalities of acroporid corals and the urchin Diadema in 1983, and coral bleaching beginning in 1987, correlate with the years of maximum dust flux into the Caribbean. Besides crustal elements, in particular Fe, Si, and aluminosilicate clays, the dust can serve as a substrate for numerous species of viable spores, especially the soil fungus Aspergillus. Aspergillus sydowii, the cause of an ongoing Caribbean-wide seafan disease, has been cultured from Caribbean air samples and used to inoculate sea fans.

  17. Farming behaviour of reef fishes increases the prevalence of coral disease associated microbes and black band disease.

    Science.gov (United States)

    Casey, Jordan M; Ainsworth, Tracy D; Choat, J Howard; Connolly, Sean R

    2014-08-01

    Microbial community structure on coral reefs is strongly influenced by coral-algae interactions; however, the extent to which this influence is mediated by fishes is unknown. By excluding fleshy macroalgae, cultivating palatable filamentous algae and engaging in frequent aggression to protect resources, territorial damselfish (f. Pomacentridae), such as Stegastes, mediate macro-benthic dynamics on coral reefs and may significantly influence microbial communities. To elucidate how Stegastes apicalis and Stegastes nigricans may alter benthic microbial assemblages and coral health, we determined the benthic community composition (epilithic algal matrix and prokaryotes) and coral disease prevalence inside and outside of damselfish territories in the Great Barrier Reef, Australia. 16S rDNA sequencing revealed distinct bacterial communities associated with turf algae and a two to three times greater relative abundance of phylotypes with high sequence similarity to potential coral pathogens inside Stegastes's territories. These potentially pathogenic phylotypes (totalling 30.04% of the community) were found to have high sequence similarity to those amplified from black band disease (BBD) and disease affected corals worldwide. Disease surveys further revealed a significantly higher occurrence of BBD inside S. nigricans's territories. These findings demonstrate the first link between fish behaviour, reservoirs of potential coral disease pathogens and the prevalence of coral disease. PMID:24966320

  18. Contrasting responses of coral reef fauna and foraminiferal assemblages to human influence in La Parguera, Puerto Rico

    Science.gov (United States)

    Coral reef biota including stony corals, sponges, gorgonians, fish, benthic macroinvertebrates and foraminifera were surveyed in coastal waters near La Parguera, in southwestern Puerto Rico. The goal was to evaluate sensitivity of coral reef biological indicators to human distur...

  19. Factors Affecting Detection Probability of Acoustic Tags in Coral Reefs

    KAUST Repository

    Bermudez, Edgar F.

    2012-05-01

    Acoustic telemetry is an important tool for studying the movement patterns, behaviour, and site fidelity of marine organisms; however, its application is challenged in coral reef environments where complex topography and intense environmental noise interferes with acoustic signals, and there has been less study. Therefore, it is particularly critical in coral reef telemetry studies to first conduct a long-term range test, a tool that provides informa- tion on the variability and periodicity of the transmitter detection range and the detection probability. A one-month range test of a coded telemetric system was conducted prior to a large-scale tagging project investigating the movement of approximately 400 fishes from 30 species on offshore coral reefs in the central Red Sea. During this range test we determined the effect of the following factors on transmitter detection efficiency: distance from receiver, time of day, depth, wind, current, moon-phase and temperature. The experiment showed that biological noise is likely to be responsible for a diel pattern of -on average- twice as many detections during the day as during the night. Biological noise appears to be the most important noise source in coral reefs overwhelming the effect of wind-driven noise, which is important in other studies. Detection probability is also heavily influenced by the location of the acoustic sensor within the reef structure. Understanding the effect of environmental factors on transmitter detection probability allowed us to design a more effective receiver array for the large-scale tagging study.

  20. Advancing Ocean Monitoring Near Coral Reefs

    Science.gov (United States)

    Heron, Scott F.; Steinberg, Craig R.; Heron, Mal L.; Mantovanelli, Alessandra; Jaffrés, Jasmine B. D.; Skirving, William J.; McAllister, Felicity; Rigby, Paul; Wisdom, Daniel; Bainbridge, Scott

    2010-10-01

    Corals, the foundation of tropical marine ecosystems, exist in a symbiotic relationship with zooxanthellae (algae). The corals obtain much of their energy by consuming compounds derived from photosynthesis by these microorganisms; the microorganisms, which reside in the coral tissue, in turn use waste products from the corals to sustain photosynthesis. This symbiosis is very sensitive to subtle changes in environment, such as increased ocean acidity, temperature, and light. When unduly stressed, the colorful algae are expelled from the corals, causing the corals to “bleach” and potentially die [e.g., van Oppen and Lough, 2009].

  1. The functioning of coral reef communities along environmental gradients

    OpenAIRE

    Plass-Johnson, Jeremiah

    2015-01-01

    One of the primary challenges in ecology is to understand how environmental disturbance affects diversity and community structure, and what are the subsequent consequences on ecosystem functioning. Coral reefs are some of the most diverse ecosystems on the planet resulting in complex sets of interactions between benthic, habitat-forming constituents and mobile fish consumers. However, scleractinian corals, the primary habitat engineers, are dependent on high-light, low-nutrient water conditio...

  2. Sponge diversity and community composition in Irish bathyal coral reefs

    OpenAIRE

    Soest, van, A.J.; Cleary, D.F.R.; Kluijver, de, M.; Lavaleye, M.S.S.; Maier, C.; Duy, van, F.C.

    2007-01-01

    Sponge diversity and community composition in bathyal cold water coral reefs (CWRs) were examined at 500-900 m depth on the southeastern slopes of Rockall Bank and the northwestern slope of Porcupine Bank, to the west of Ireland in 2004 and 2005 with boxcores. A total of 104 boxcore samples, supplemented with 10 trawl/dredge attempts, were analyzed for the presence and abundance of sponges, using microscopical examination of (sub)samples of collected coral branches, and semi-quantitative macr...

  3. The future of evolutionary diversity in reef corals

    OpenAIRE

    Huang, Danwei; Roy, Kaustuv

    2015-01-01

    One-third of the world's reef-building corals are facing heightened extinction risk from climate change and other anthropogenic impacts. Previous studies have shown that such threats are not distributed randomly across the coral tree of life, and future extinctions have the potential to disproportionately reduce the phylogenetic diversity of this group on a global scale. However, the impact of such losses on a regional scale remains poorly known. In this study, we use phylogenetic metrics in ...

  4. Holocene emerged coral reef in Takarajima and Kodakarajima, Ryukyu islands, Southwest Japan

    International Nuclear Information System (INIS)

    Due to the recent development of radiometric dating, coral reefs emerged in Holocene epoch are studied intensively worldwidely in relation to sea level change and coral reef formation. Attempt was made to determine the age, pattern and growth rate of coral reefs in the marginal area of coral sea in the Northwest Pacific. Field observation was made in the emerged coral reefs in Takarajima and Kodakarajima islands and the samples for radiocarbon dating were taken from geological sections across the emerged reefs. These islands are located at about 29 deg 10 min N, 129 deg 15 min E, where warm Kuroshio current pushes the margin of coral sea northward, and furnished with flourishing development of coral reefs emerged in both pleistocence and Holocene epochs. Though without earthquake records, it is assumed that Holocene reefs have been terraced due to sudden uplift associated with major earthquakes. (Mori, K.)

  5. Current status, crisis and conservation of coral reef ecosystems in China

    Directory of Open Access Journals (Sweden)

    ShaoHong Wu

    2012-03-01

    Full Text Available Harboring rich marine species and playing important ecological functions, coral reef ecosystems have attracted widespread concern around the world. Ecosystem diversity, conservation and management of coral reefs are becoming a hot research area. Coral reefs in China are mainly distributed in the South China Sea and Hainan, Taiwan, Hong Kong, Guangdong, and Guangxi coastal waters. In recent years, due to the global climate change and the growing impact of human activities, coral reef biodiversity in China have been reducing and the ecological functions of coral reef ecosystems are severely degenerating. In this paper we summarized the current status, crisis and conservation of coral reef ecosystems in China. Some progress in coral reef research was discussed.

  6. Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs.

    Directory of Open Access Journals (Sweden)

    Claire L A Dell

    Full Text Available Many reefs have shifted from coral and fish dominated habitats to less productive macroalgal dominated habitats, and current research is investigating means of reversing this phase shift. In the tropical Pacific, overfished reefs with inadequate herbivory can become dominated by the brown alga Sargassum polycystum. This alga suppresses recruitment and survival of corals and fishes, thus limiting the potential for reef recovery. Here we investigate the mechanisms that reinforce S. polycystum dominance and show that in addition to negatively affecting other species, this species acts in a self-reinforcing manner, positively promoting survival and growth of conspecifics. We found that survival and growth of both recruit-sized and mature S. polycystum fronds were higher within Sargassum beds than outside the beds and these results were found in both protected and fished reefs. Much of this benefit resulted from reduced herbivory within the Sargassum beds, but adult fronds also grew ~50% more within the beds even when herbivory did not appear to be occurring, suggesting some physiological advantage despite the intraspecific crowding. Thus via positive feedbacks, S. polycystum enhances its own growth and resistance to herbivores, facilitating its dominance (perhaps also expansion and thus its resilience on degraded reefs. This may be a key feedback mechanism suppressing the recovery of coral communities in reefs dominated by macroalgal beds.

  7. Positive Feedbacks Enhance Macroalgal Resilience on Degraded Coral Reefs.

    Science.gov (United States)

    Dell, Claire L A; Longo, Guilherme O; Hay, Mark E

    2016-01-01

    Many reefs have shifted from coral and fish dominated habitats to less productive macroalgal dominated habitats, and current research is investigating means of reversing this phase shift. In the tropical Pacific, overfished reefs with inadequate herbivory can become dominated by the brown alga Sargassum polycystum. This alga suppresses recruitment and survival of corals and fishes, thus limiting the potential for reef recovery. Here we investigate the mechanisms that reinforce S. polycystum dominance and show that in addition to negatively affecting other species, this species acts in a self-reinforcing manner, positively promoting survival and growth of conspecifics. We found that survival and growth of both recruit-sized and mature S. polycystum fronds were higher within Sargassum beds than outside the beds and these results were found in both protected and fished reefs. Much of this benefit resulted from reduced herbivory within the Sargassum beds, but adult fronds also grew ~50% more within the beds even when herbivory did not appear to be occurring, suggesting some physiological advantage despite the intraspecific crowding. Thus via positive feedbacks, S. polycystum enhances its own growth and resistance to herbivores, facilitating its dominance (perhaps also expansion) and thus its resilience on degraded reefs. This may be a key feedback mechanism suppressing the recovery of coral communities in reefs dominated by macroalgal beds. PMID:27186979

  8. Remote sensing of coral reefs and their physical environment

    International Nuclear Information System (INIS)

    There has been a vast improvement in access to remotely sensed data in just a few recent years. This revolution of information is the result of heavy investment in new technology by governments and industry, rapid developments in computing power and storage, and easy dissemination of data over the internet. Today, remotely sensed data are available to virtually anyone with a desktop computer. Here, we review the status of one of the most popular areas of marine remote sensing research: coral reefs. Previous reviews have focused on the ability of remote sensing to map the structure and habitat composition of coral reefs, but have neglected to consider the physical environment in which reefs occur. We provide a holistic review of what can, might, and cannot be mapped using remote sensing at this time. We cover aspects of reef structure and health but also discuss the diversity of physical environmental data such as temperature, winds, solar radiation and water quality. There have been numerous recent advances in the remote sensing of reefs and we hope that this paper enhances awareness of the diverse data sources available, and helps practitioners identify realistic objectives for remote sensing in coral reef areas

  9. Community structure and coral status across reef fishing intensity gradients in Palk Bay reef, southeast coast of India.

    Digital Repository Service at National Institute of Oceanography (India)

    Manikandan, B.; Ravindran, J.; Shrinivaasu, S.; Marimuthu, N.; Paramasivam, K.

    Healthy live coral (LC/H), Live coral colonized by turf algae (LC/TA) and Live coral colonized by macro algae (LC/MA). 2.3 Reef fish survey The diversity and the quantity of commercially exploited reef fishes in the Palk bay reef was surveyed through... in MRC, comparatively higher than the sites influenced by reef fishing.. The diversity of corals present in the study sites were summarized in the Table 2. As per the results of Bray-Curtis cluster analysis under paired linkage the study sites were...

  10. Climate-change refugia: shading reef corals by turbidity.

    Science.gov (United States)

    Cacciapaglia, Chris; van Woesik, Robert

    2016-03-01

    Coral reefs have recently experienced an unprecedented decline as the world's oceans continue to warm. Yet global climate models reveal a heterogeneously warming ocean, which has initiated a search for refuges, where corals may survive in the near future. We hypothesized that some turbid nearshore environments may act as climate-change refuges, shading corals from the harmful interaction between high sea-surface temperatures and high irradiance. We took a hierarchical Bayesian approach to determine the expected distribution of 12 coral species in the Indian and Pacific Oceans, between the latitudes 37°N and 37°S, under representative concentration pathway 8.5 (W m(-2) ) by 2100. The turbid nearshore refuges identified in this study were located between latitudes 20-30°N and 15-25°S, where there was a strong coupling between turbidity and tidal fluctuations. Our model predicts that turbidity will mitigate high temperature bleaching for 9% of shallow reef habitat (to 30 m depth) - habitat that was previously considered inhospitable under ocean warming. Our model also predicted that turbidity will protect some coral species more than others from climate-change-associated thermal stress. We also identified locations where consistently high turbidity will likely reduce irradiance to Japan), eastern Vietnam, western and eastern Australia, New Caledonia, the northern Red Sea, and the Arabian Gulf, should become part of a judicious global strategy for reef-coral persistence under climate change. PMID:26695523

  11. Habitat structure, degradation and management effects on coral reef fish communities

    OpenAIRE

    Yahya, Saleh A.S.

    2011-01-01

    Coral reefs are among the most diverse and productive ecosystems on earth, and are critical to the survival of tropical marine ecosystems and sustenance of local human populations. However, coral reefs are quite vulnerable to disturbances, both natural and anthropogenic. This thesis looks at how coral reef communities have responded to climactic disturbances, particularly the 1997-98 El Niño Southern Oscillation (ENSO) and subsequent coral bleaching and mortality that affected much of the Ind...

  12. Synergistic impacts of global warming on the resilience of coral reefs

    OpenAIRE

    Bozec, Yves-Marie; Peter J Mumby

    2015-01-01

    Recent epizootics have removed important functional species from Caribbean coral reefs and left communities vulnerable to alternative attractors. Global warming will impact reefs further through two mechanisms. A chronic mechanism reduces coral calcification, which can result in depressed somatic growth. An acute mechanism, coral bleaching, causes extreme mortality when sea temperatures become anomalously high. We ask how these two mechanisms interact in driving future reef state (coral cover...

  13. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    OpenAIRE

    Mace G. Barron; Cheryl J. McGill; Lee A. Courtney; Marcovich, Dragoslav T

    2010-01-01

    Determining stressor-response relationships in reef building corals continues to be a critical research need due to global declines in coral reef ecosystems and projected declines for the future. A simplified recirculating coral exposure system was coupled to a solar simulator to allow laboratory testing of a diversity of species and morphologies of reef building corals under ecologically relevant conditions of temperature and solar radiation. Combinations of lamps and attenuating filters al...

  14. An exceptionally preserved Eocene shark and the rise of modern predator–prey interactions in the coral reef food web

    OpenAIRE

    Fanti, Federico; Minelli, Daniela; Conte, Gabriele Larocca; Miyashita, Tetsuto

    2016-01-01

    Background Following extreme climatic warming events, Eocene Lagerstätten document aquatic and terrestrial vertebrate faunas surprisingly similar to modern counterparts. This transition in marine systems is best documented in the earliest teleost-dominated coral reef assemblage of Pesciara di Bolca, northern Italy, from near the end of the Eocene Climatic Optimum. Its rich fauna shows similarities with that of the modern Great Barrier Reef in niche exploitation by and morphological disparity ...

  15. Effects of reduced water quality on coral reefs in and out of no-take marine reserves.

    Science.gov (United States)

    Wenger, Amelia S; Williamson, David H; da Silva, Eduardo T; Ceccarelli, Daniela M; Browne, Nicola K; Petus, Caroline; Devlin, Michelle J

    2016-02-01

    Near-shore marine environments are increasingly subjected to reduced water quality, and their ability to withstand it is critical to their persistence. The potential role marine reserves may play in mitigating the effects of reduced water quality has received little attention. We investigated the spatial and temporal variability in live coral and macro-algal cover and water quality during moderate and major flooding events of the Fitzroy River within the Keppel Bay region of the Great Barrier Reef Marine Park from 2007 to 2013. We used 7 years of remote sensing data on water quality and data from long-term monitoring of coral reefs to quantify exposure of coral reefs to flood plumes. We used a distance linear model to partition the contribution of abiotic and biotic factors, including zoning, as drivers of the observed changes in coral and macro-algae cover. Moderate flood plumes from 2007 to 2009 did not affect coral cover on reefs in the Keppel Islands, suggesting the reef has intrinsic resistance against short-term exposure to reduced water quality. However, from 2009 to 2013, live coral cover declined by ∼ 50% following several weeks of exposure to turbid, low salinity water from major flood plume events in 2011 and subsequent moderate events in 2012 and 2013. Although the flooding events in 2012 and 2013 were smaller than the flooding events between 2007 to 2009, the ability of the reefs to withstand these moderate floods was lost, as evidenced by a ∼ 20% decline in coral cover between 2011 to 2013. Although zoning (no-take reserve or fished) was identified a significant driver of coral cover, we recorded consistently lower coral cover on reserve reefs than on fished reefs throughout the study period and significantly lower cover in 2011. Our findings suggest that even reefs with an inherent resistance to reduced water quality are not able to withstand repeated disturbance events. The limitations of reserves in mitigating the effects of reduced water

  16. Linking habitat mosaics and connectivity in a coral reef seascape

    KAUST Repository

    McMahon, Kelton

    2012-09-04

    Tropical marine ecosystems are under mounting anthropogenic pressure from overfishing and habitat destruction, leading to declines in their structure and function on a global scale. Although maintaining connectivity among habitats within a seascape is necessary for preserving population resistance and resilience, quantifying movements of individuals within seascapes remains challenging. Traditional methods of identifying and valuing potential coral reef fish nursery habitats are indirect, often relying on visual surveys of abundance and correlations of size and biomass among habitats. We used compound-specific stable isotope analyses to determine movement patterns of commercially important fish populations within a coral reef seascape. This approach allowed us to quantify the relative contributions of individuals from inshore nurseries to reef populations and identify migration corridors among important habitats. Our results provided direct measurements of remarkable migrations by juvenile snapper of over 30 km, between nurseries and reefs. We also found significant plasticity in juvenile nursery residency. Although a majority of individuals on coastal reefs had used seagrass nurseries as juveniles, many adults on oceanic reefs had settled directly into reef habitats. Moreover, seascape con figuration played a critical but heretofore unrecognized role in determining connectivity among habitats. Finally, our approach provides key quantitative data necessary to estimate the value of distinctive habitats to ecosystem services provided by seascapes.

  17. Coral degradation and ability of rehabilitation of coral reefs in Co To Archipelago, Quang Ninh province, Vietnam

    Science.gov (United States)

    Ngai, Nguyen Dang; Cu, Nguyen Duc; Tuyet, Dao Anh

    2013-11-01

    Serious degradation of coral reefs in the Co To Archipelago occurred from 2002 to 2006. Nearly 80% of the species and over 90% of living coral cover were lost and some reefs were completely dead. Currently, the highest coral cover is only 7.5% where previously most of the reefs had over 50% live coral cover. The cause of the reef degradation has been identified to be residues of cyanide used by local fishermen for fishing on reefs. To overcome the consequences transplantation corals on natural and artificial shelters were attempted. Survival rate on artificial shelters was 88.3% after 2 years and growth rate averaged 2.3 cm/year. Transplanted corals on natural shelters had lower survival rate, 55.9%. The natural recovery of coral on degraded reefs was also monitored periodically in this study. No coral recruitment was seen on completely dead reefs whereas there was little new coral recruitment on reefs with some remaining live corals.

  18. Artificial reef structures and coral transplantation: fish community responses and effects on coral recruitment in North Sulawesi/Indonesia

    OpenAIRE

    Ferse, Sebastian

    2008-01-01

    Artificial reefs alone and in combination with coral transplants (branching Acropora and Pocillopora species) were deployed in 100 m2 plots at three locations (Gangga, Meras and Bunaken) in North Sulawesi/Indonesia in order to study the effects on the associated reef fish community and on coral recruitment dynamics. Control plots covered with coral rubble were monitored for comparison. The study was carried out between May 2005 and July 2007. Coral recruitment was studied using limestone sett...

  19. The Coral Reef Alphabet Book for American Samoa.

    Science.gov (United States)

    Madrigal, Larry G.

    This book, produced for the American Samoa Department of Education Marine Enhancement Program, presents underwater color photography of coral reef life in an alphabetical resource. The specimens are described in English, and some are translated into the Samoan language. A picture-matching learning exercise and a glossary of scientific and oceanic…

  20. Sponge diversity and community composition in Irish bathyal coral reefs

    NARCIS (Netherlands)

    Soest, van R.W.M; Cleary, D.F.R.; Kluijver, de M.J.; Lavaleye, M.S.S.; Maier, C.; Duy, van F.C.

    2007-01-01

    Sponge diversity and community composition in bathyal cold water coral reefs (CWRs) were examined at 500-900 m depth on the southeastern slopes of Rockall Bank and the northwestern slope of Porcupine Bank, to the west of Ireland in 2004 and 2005 with boxcores. A total of 104 boxcore samples, supplem

  1. Ecology: The Upside-Down World of Coral Reef Predators.

    Science.gov (United States)

    Simpfendorfer, Colin A; Heupel, Michelle R

    2016-08-01

    Examination of a large aggregation of sharks demonstrates that trophic pyramids with greater amounts of high-level predators than prey can occur on coral reefs. This is possible because the high-level predators obtain food from sources outside their home location. PMID:27505241

  2. Biological Criteria for Protection of U.S. Coral Reefs.

    Science.gov (United States)

    Coral reef ecosystems are threatened by natural stressors, human activities, and natural stressors exacerbated by human activities. Under the U.S. Clean Water Act, States and Territories may guard against anthropogenic threats by adopting water quality standards based on biologic...

  3. Coral Reefs at the Northernmost Tip of Borneo: An Assessment of Scleractinian Species Richness Patterns and Benthic Reef Assemblages.

    Directory of Open Access Journals (Sweden)

    Zarinah Waheed

    Full Text Available The coral reefs at the northernmost tip of Sabah, Borneo will be established under a marine protected area: the Tun Mustapha Park (TMP by the end of 2015. This area is a passage where the Sulu Sea meets the South China Sea and it is situated at the border of the area of maximum marine biodiversity, the Coral Triangle. The TMP includes fringing and patch reefs established on a relatively shallow sea floor. Surveys were carried out to examine features of the coral reefs in terms of scleractinian species richness, and benthic reef assemblages following the Reef Check substrate categories, with emphasis on hard coral cover. Variation in scleractinian diversity was based on the species composition of coral families Fungiidae (n = 39, Agariciidae (n = 30 and Euphylliidae (n = 15. The number of coral species was highest at reefs with a larger depth gradient i.e. at the periphery of the study area and in the deep South Banggi Channel. Average live hard coral cover across the sites was 49%. Only 7% of the examined reefs had > 75% hard coral cover, while the majority of the reef sites were rated fair (51% and good (38%. Sites with low coral cover and high rubble fragments are evidence of blast fishing, although the observed damage appeared old. Depth was a dominant factor in influencing the coral species composition and benthic reef communities in the TMP. Besides filling in the information gaps regarding species richness and benthic cover for reef areas that were previously without any data, the results of this study together with information that is already available on the coral reefs of TMP will be used to make informed decisions on zoning plans for conservation priorities in the proposed park.

  4. Coral Reefs at the Northernmost Tip of Borneo: An Assessment of Scleractinian Species Richness Patterns and Benthic Reef Assemblages

    Science.gov (United States)

    Waheed, Zarinah; van Mil, Harald G. J.; Syed Hussein, Muhammad Ali; Jumin, Robecca; Golam Ahad, Bobita; Hoeksema, Bert W.

    2015-01-01

    The coral reefs at the northernmost tip of Sabah, Borneo will be established under a marine protected area: the Tun Mustapha Park (TMP) by the end of 2015. This area is a passage where the Sulu Sea meets the South China Sea and it is situated at the border of the area of maximum marine biodiversity, the Coral Triangle. The TMP includes fringing and patch reefs established on a relatively shallow sea floor. Surveys were carried out to examine features of the coral reefs in terms of scleractinian species richness, and benthic reef assemblages following the Reef Check substrate categories, with emphasis on hard coral cover. Variation in scleractinian diversity was based on the species composition of coral families Fungiidae (n = 39), Agariciidae (n = 30) and Euphylliidae (n = 15). The number of coral species was highest at reefs with a larger depth gradient i.e. at the periphery of the study area and in the deep South Banggi Channel. Average live hard coral cover across the sites was 49%. Only 7% of the examined reefs had > 75% hard coral cover, while the majority of the reef sites were rated fair (51%) and good (38%). Sites with low coral cover and high rubble fragments are evidence of blast fishing, although the observed damage appeared old. Depth was a dominant factor in influencing the coral species composition and benthic reef communities in the TMP. Besides filling in the information gaps regarding species richness and benthic cover for reef areas that were previously without any data, the results of this study together with information that is already available on the coral reefs of TMP will be used to make informed decisions on zoning plans for conservation priorities in the proposed park. PMID:26719987

  5. Forecasting decadal changes in sea surface temperatures and coral bleaching within a Caribbean coral reef

    Science.gov (United States)

    Li, Angang; Reidenbach, Matthew A.

    2014-09-01

    Elevated sea surface temperature (SST) caused by global warming is one of the major threats to coral reefs. While increased SST has been shown to negatively affect the health of coral reefs by increasing rates of coral bleaching, how changes to atmospheric heating impact SST distributions, modified by local flow environments, has been less understood. This study aimed to simulate future water flow patterns and water surface heating in response to increased air temperature within a coral reef system in Bocas del Toro, Panama, located within the Caribbean Sea. Water flow and SST were modeled using the Delft3D-FLOWcomputer simulation package. Locally measured physical parameters, including bathymetry, astronomic tidal forcing, and coral habitat distribution were input into the model and water flow, and SST was simulated over a four-month period under present day, as well as projected warming scenarios in 2020s, 2050s, and 2080s. Changes in SST, and hence the thermal stress to corals, were quantified by degree heating weeks. Results showed that present-day reported bleaching sites were consistent with localized regions of continuous high SST. Regions with highest SST were located within shallow coastal sites adjacent to the mainland or within the interior of the bay, and characterized by low currents with high water retention times. Under projected increases in SSTs, shallow reef areas in low flow regions were found to be hot spots for future bleaching.

  6. Human Dimensions of Coral Reef Social-Ecological Systems

    Directory of Open Access Journals (Sweden)

    John N. Kittinger

    2012-12-01

    Full Text Available Coral reefs are among the most diverse ecosystems on the planet but are declining because of human activities. Despite general recognition of the human role in the plight of coral reefs, the vast majority of research focuses on the ecological rather than the human dimensions of reef ecosystems, limiting our understanding of social relationships with these environments as well as potential solutions for reef recovery. General frameworks for social-ecological systems (SESs have been advanced, but system-specific approaches are needed to develop a more nuanced view of human-environmental interactions for specific contexts and resource systems, and at specific scales. We synthesize existing concepts related to SESs and present a human dimensions framework that explores the linkages between social system structural traits, human activities, ecosystem services, and human well-being in coral reef SESs. Key features of the framework include social-ecological reciprocity, proximate and underlying dimensions, and the directionality of key relationships and feedback loops. Such frameworks are needed if human dimensions research is to be more fully integrated into studies of ecosystem change and the sustainability of linked SESs.

  7. Ocean acidification: Linking science to management solutions using the Great Barrier Reef as a case study.

    Science.gov (United States)

    Albright, Rebecca; Anthony, Kenneth R N; Baird, Mark; Beeden, Roger; Byrne, Maria; Collier, Catherine; Dove, Sophie; Fabricius, Katharina; Hoegh-Guldberg, Ove; Kelly, Ryan P; Lough, Janice; Mongin, Mathieu; Munday, Philip L; Pears, Rachel J; Russell, Bayden D; Tilbrook, Bronte; Abal, Eva

    2016-11-01

    Coral reefs are one of the most vulnerable ecosystems to ocean acidification. While our understanding of the potential impacts of ocean acidification on coral reef ecosystems is growing, gaps remain that limit our ability to translate scientific knowledge into management action. To guide solution-based research, we review the current knowledge of ocean acidification impacts on coral reefs alongside management needs and priorities. We use the world's largest continuous reef system, Australia's Great Barrier Reef (GBR), as a case study. We integrate scientific knowledge gained from a variety of approaches (e.g., laboratory studies, field observations, and ecosystem modelling) and scales (e.g., cell, organism, ecosystem) that underpin a systems-level understanding of how ocean acidification is likely to impact the GBR and associated goods and services. We then discuss local and regional management options that may be effective to help mitigate the effects of ocean acidification on the GBR, with likely application to other coral reef systems. We develop a research framework for linking solution-based ocean acidification research to practical management options. The framework assists in identifying effective and cost-efficient options for supporting ecosystem resilience. The framework enables on-the-ground OA management to be the focus, while not losing sight of CO2 mitigation as the ultimate solution. PMID:27564868

  8. Decline of coral reefs during late Paleocene to early Eocene global warming

    OpenAIRE

    Scheibner, C; Speijer, R. P.

    2007-01-01

    International audience Since the 1980s the frequency of warming events has intensified and simultaneously widespread coral bleaching, and enhanced coral mortality have been observed. Yet, it remains unpredictable how tropical coral reef communities will react to prolonged adverse conditions. Possibly, coral reef systems are sufficiently robust to withstand continued environmental pressures. But if coral mortality increases, what will platform communities of the future look like? The co-evo...

  9. Origins and Implications of a Primary Crown-of-Thorns Starfish Outbreak in the Southern Great Barrier Reef

    OpenAIRE

    Ian Miller; Hugh Sweatman; Alistair Cheal; Mike Emslie; Kerryn Johns; Michelle Jonker; Kate Osborne

    2015-01-01

    The crown-of-thorns starfish (COTS) is a major predator of hard corals. Repeated COTS outbreaks in the Cairns and Central sections of the Great Barrier Reef (GBR) have been responsible for greater declines in coral cover than any other type of disturbance, including cyclones, disease, and coral bleaching. Knowledge of the precise timing and location of primary outbreaks could reveal the initial drivers of outbreaks and so could indicate possible management measures. In the central GBR, COTS o...

  10. Influence of reef geometry on wave attenuation on a Brazilian coral reef

    Science.gov (United States)

    Costa, Mirella B. S. F.; Araújo, Moacyr; Araújo, Tereza C. M.; Siegle, Eduardo

    2016-01-01

    This study presents data from field experiments that focus on the influence of coral reef geometry on wave transformation in the Metropolitan Area of Recife (MAR) on the northeast coast of Brazil. First, a detailed bathymetric survey was conducted, revealing a submerged reef bank, measuring 18 km long by 1 km wide, parallel to the coastline with a quasi-horizontal top that varies from 0.5 m to 4 m in depth at low tide. Cluster similarity between 180 reef profiles indicates that in 75% of the area, the reef geometry has a configuration similar to a platform reef, whereas in 25% of the area it resembles a fringing reef. Measurements of wave pressure fluctuations were made at two stations (experiments E1 and E2) across the reef profile. The results indicate that wave height was tidally modulated at both experimental sites. Up to 67% (E1) and 99.9% (E2) of the incident wave height is attenuated by the reef top at low tide. This tidal modulation is most apparent at E2 due to reef geometry. At this location, the reef top is only approximately 0.5 m deep during mean low spring water, and almost all incident waves break on the outer reef edge. At E1, the reef top depth is 4 m, and waves with height ratios smaller than the critical breaking limit are free to pass onto the reef and are primarily attenuated by bottom friction. These results highlight the importance of reef geometry in controlling wave characteristics of the MAR beaches and demonstrate its effect on the morphology of the adjacent coast. Implications of differences in wave attenuation and the level of protection provided by the reefs to the adjacent shoreline are discussed.

  11. Sexual reproduction of Acropora reef corals at Moorea, French Polynesia

    Science.gov (United States)

    Carroll, A.; Harrison, P.; Adjeroud, M.

    2006-03-01

    Little information is available on reproductive processes among corals in isolated central Pacific reef regions, including French Polynesia. This study examined the timing and mode of sexual reproduction for Acropora reef corals at Moorea. Spawning was observed and/or inferred in 110 Acropora colonies, representing 12 species, following full moon periods in September through November 2002. Gamete release was observed and inferred in four species of Acropora between 9 and 13 nights after the full moon (nAFM) in September 2002. Twelve Acropora spp. spawned gametes between 5 and 10 nAFM in October 2002, with six species spawning 7 nAFM and four species spawning 9 nAFM. In November 2002, spawning of egg and sperm bundles was observed and inferred in 27 colonies of Acropora austera, 6 nAFM. These are the first detailed records of spawning by Acropora corals in French Polynesia.

  12. 77 FR 12243 - Proposed Information Collection; Comment Request; Pacific Islands Region Coral Reef Ecosystems...

    Science.gov (United States)

    2012-02-29

    ... Islands Region Coral Reef Ecosystems Permit Form AGENCY: National Oceanic and Atmospheric Administration... vessel to fish for Western Pacific coral reef ecosystem management unit species in the designated low-use... reef ecosystem regulatory area, to obtain and carry a permit. A receiving vessel must also have...

  13. Assessing threats from coral and crustose coralline algae disease on the reefs of New Caledonia

    OpenAIRE

    Aeby, G.; Tribollet, Aline; Lasne, G.; Work, T.

    2016-01-01

    The present study reports the results of the first quantitative survey of lesions on coral and crustose coralline algae (CCA) on reefs in the lagoon of New Caledonia. Surveys on inshore and offshore reefs were conducted at 13 sites in 2010, with 12 sites resurveyed in 2013. Thirty coral diseases affecting 15 coral genera were found, with low overall disease prevalence (

  14. The DNA of coral reef biodiversity : predicting and protecting genetic diversity of reef assemblages

    OpenAIRE

    Selkoe, Kim; Gaggiotti, Oscar Eduardo; Treml, Eric; Wren, Johanna; Donovan, Marie; Consortium, Hawaii Reef Connectivity; Toonen, Robert

    2016-01-01

    O.E.G. was supported by the Marine Alliance for Science and Technology for Scotland (MASTS). Conservation of ecological communities requires deepening our understanding of genetic diversity patterns and drivers at community-wide scales. Here we use seascape genetic analysis of a diversity metric, allelic richness, for 47 reef species sampled across 13 Hawaiian Islands to empirically demonstrate that large reefs high in coral cover harbor the greatest genetic diversity on average. We found ...

  15. Spatial patterns in benthic communities and the dynamics of a mosaic ecosystem on the Great Barrier Reef, Australia

    Science.gov (United States)

    Ninio, R.; Meekan, M.

    2002-04-01

    The benthic communities of the Great Barrier Reef (GBR) have been characterized as a mosaic with patches at scales of tens to hundreds of kilometres formed by clusters of reefs with comparable environmental settings and histories of disturbance. We use data sets of changes in cover of abundant benthic organisms to examine the relationship between community composition and the dynamics of this mosaic. Our data were compiled from seven annual video surveys of permanent transects on the north-east flanks of up to 52 reefs at different shelf positions throughout most of the GBR. Classification analysis of these data sets identified three distinct groups of reefs, the first dominated by poritid hard corals and alcyoniid soft corals, the second by hard corals of the genus Acropora, and the third by xeniid soft corals. These groups underwent different amounts of change in cover during the period of our study. As acroporan corals are fast growing but susceptible to mortality due to predators and wave action, the group of reefs dominated by this genus displayed rapid rates of growth and loss of cover. In contrast, cover in the remaining groups changed very slowly or remained stable. Some evidence suggests that competition for space may limit growth of acroporan corals and thus rates of change in the group dominated by xeniid soft corals. These contrasting patterns imply that susceptibility to, and recovery from, disturbances such as cyclones, predators, and bleaching events will differ among these groups of reefs.

  16. Status of Kenyan Coral Reef lagoons. Project Report to Kenya Wildlife Services, Kenya Karine and Fisheries Researoh Institute & Kenya"s Fisheries Department.

    OpenAIRE

    McClanahan, T.; Muthiga, N.; OBURA, D.; Mutere, J.; Mwachireya, S.

    1992-01-01

    This report presents the findings of Wildlife Conservation International's Coral Reef Conservation Project monitoring program of Kenyan coral reefs and suggest research and management plans for the coral reefs based on the findings.

  17. Workshop on Biological Integrity of Coral Reefs August 21-22, 2012, Caribbean Coral Reef Institute, Isla Magueyes, La Parguera, Puerto Rico.

    Science.gov (United States)

    This report summarizes an EPA-sponsored workshop on coral reef biological integrity held at the Caribbean Coral Reef Institute in La Parguera, Puerto Rico on August 21-22, 2012. The goals of this workshop were to:• Identify key qualitative and quantitative ecological characterist...

  18. Contaminants assessment in the coral reefs of Virgin Islands National Park and Virgin Islands Coral Reef National Monument

    Science.gov (United States)

    Bargar, Timothy A.; Garrison, Virginia H.; Alvarez, David A.; Echols, Kathy

    2013-01-01

    Coral, fish, plankton, and detritus samples were collected from coral reefs in Virgin Islands National Park (VIIS) and Virgin Islands Coral Reef National Monument (VICR) to assess existing contamination levels. Passive water sampling using polar organic chemical integrative samplers (POCIS) and semi-permeable membrane devices found a few emerging pollutants of concern (DEET and galaxolide) and polynuclear aromatic hydrocarbons. Very little persistent organic chemical contamination was detected in the tissue or detritus samples. Detected contaminants were at concentrations below those reported to be harmful to aquatic organisms. Extracts from the POCIS were subjected to the yeast estrogen screen (YES) to assess potential estrogenicity of the contaminant mixture. Results of the YES (estrogen equivalency of 0.17–0.31 ng/L 17-β-estradiol) indicated a low estrogenicity likelihood for contaminants extracted from water. Findings point to low levels of polar and non-polar organic contaminants in the bays sampled within VICR and VIIS.

  19. Modelling coral reef futures to inform management: can reducing local-scale stressors conserve reefs under climate change?

    Directory of Open Access Journals (Sweden)

    Georgina G Gurney

    Full Text Available Climate change has emerged as a principal threat to coral reefs, and is expected to exacerbate coral reef degradation caused by more localised stressors. Management of local stressors is widely advocated to bolster coral reef resilience, but the extent to which management of local stressors might affect future trajectories of reef state remains unclear. This is in part because of limited understanding of the cumulative impact of multiple stressors. Models are ideal tools to aid understanding of future reef state under alternative management and climatic scenarios, but to date few have been sufficiently developed to be useful as decision support tools for local management of coral reefs subject to multiple stressors. We used a simulation model of coral reefs to investigate the extent to which the management of local stressors (namely poor water quality and fishing might influence future reef state under varying climatic scenarios relating to coral bleaching. We parameterised the model for Bolinao, the Philippines, and explored how simulation modelling can be used to provide decision support for local management. We found that management of water quality, and to a lesser extent fishing, can have a significant impact on future reef state, including coral recovery following bleaching-induced mortality. The stressors we examined interacted antagonistically to affect reef state, highlighting the importance of considering the combined impact of multiple stressors rather than considering them individually. Further, by providing explicit guidance for management of Bolinao's reef system, such as which course of management action will most likely to be effective over what time scales and at which sites, we demonstrated the utility of simulation models for supporting management. Aside from providing explicit guidance for management of Bolinao's reef system, our study offers insights which could inform reef management more broadly, as well as general

  20. Diversity among macroalgae-consuming fishes on coral reefs: a transcontinental comparison.

    Directory of Open Access Journals (Sweden)

    Adriana Vergés

    Full Text Available Despite high diversity and abundance of nominally herbivorous fishes on coral reefs, recent studies indicate that only a small subset of taxa are capable of removing dominant macroalgae once these become established. This limited functional redundancy highlights the potential vulnerability of coral reefs to disturbance and stresses the need to assess the functional role of individual species of herbivores. However, our knowledge of species-specific patterns in macroalgal consumption is limited geographically, and there is a need to determine the extent to which patterns observed in specific reefs can be generalised at larger spatial scales. In this study, video cameras were used to quantify rates of macroalgae consumption by fishes in two coral reefs located at a similar latitude in opposite sides of Australia: the Keppel Islands in the Great Barrier Reef (eastern coast and Ningaloo Reef (western coast. The community of nominally herbivorous fish was also characterised in both systems to determine whether potential differences in the species observed feeding on macroalgae were related to spatial dissimilarities in herbivore community composition. The total number of species observed biting on the dominant brown alga Sargassum myriocystum differed dramatically among the two systems, with 23 species feeding in Ningaloo, compared with just 8 in the Keppel Islands. Strong differences were also found in the species composition and total biomass of nominally herbivorous fish, which was an order of magnitude higher in Ningaloo. However, despite such marked differences in the diversity, biomass, and community composition of resident herbivorous fishes, Sargassum consumption was dominated by only four species in both systems, with Naso unicornis and Kyphosus vaigiensis consistently emerging as dominant feeders of macroalgae.

  1. Metatranscriptome analysis of the reef-buidling coral Orbicella faveolata indicates holobiont response to coral disease

    Directory of Open Access Journals (Sweden)

    Camille eDaniels

    2015-09-01

    Full Text Available White Plague Disease (WPD is implicated in coral reef decline in the Caribbean and is characterized by microbial community shifts in coral mucus and tissue. Studies thus far have focused on assessing microbial communities or the identification of specific pathogens, yet few have addressed holobiont response across metaorganism compartments in coral disease. Here, we report on the first metatranscriptomic assessment of the coral host, algal symbiont, and microbial compartment in order to survey holobiont structure and function in healthy and diseased samples from Orbicella faveolata collected at reef sites off Puerto Rico. Our data indicate metaorganism-wide as well as compartment-specific responses to WPD. Gene expression changes in the diseased coral host involved proteins playing a role in innate immunity, cytoskeletal integrity, cell adhesion, oxidative stress, chemical defense, and retroelements. In contrast, the algal symbiont showed comparatively few expression changes, but of large magnitude, of genes related to stress, photosynthesis, and metal transport. Concordant with the coral host response, the bacterial compartment showed increased abundance of heat shock proteins, genes related to oxidative stress, DNA repair, and potential retroelement activity. Importantly, analysis of the expressed bacterial gene functions establishes the participation of multiple bacterial families in WPD pathogenesis and also suggests a possible involvement of viruses and/or phages in structuring the bacterial assemblage. In this study, we implement an experimental approach to partition the coral holobiont and resolve compartment- and taxa-specific responses in order to understand metaorganism function in coral disease.

  2. Metatranscriptome analysis of the reef-building coral Orbicella faveolata indicates holobiont response to coral disease

    KAUST Repository

    Daniels, Camille Arian

    2015-09-11

    White Plague Disease (WPD) is implicated in coral reef decline in the Caribbean and is characterized by microbial community shifts in coral mucus and tissue. Studies thus far have focused on assessing microbial communities or the identification of specific pathogens, yet few have addressed holobiont response across metaorganism compartments in coral disease. Here, we report on the first metatranscriptomic assessment of the coral host, algal symbiont, and microbial compartment in order to survey holobiont structure and function in healthy and diseased samples from Orbicella faveolata collected at reef sites off Puerto Rico. Our data indicate holobiont-wide as well as compartment-specific responses to WPD. Gene expression changes in the diseased coral host involved proteins playing a role in innate immunity, cytoskeletal integrity, cell adhesion, oxidative stress, chemical defense, and retroelements. In contrast, the algal symbiont showed comparatively few expression changes, but of large magnitude, of genes related to stress, photosynthesis, and metal transport. Concordant with the coral host response, the bacterial compartment showed increased abundance of heat shock proteins, genes related to oxidative stress, DNA repair, and potential retroelement activity. Importantly, analysis of the expressed bacterial gene functions establishes the participation of multiple bacterial families in WPD pathogenesis and also suggests a possible involvement of viruses and/or phages in structuring the bacterial assemblage. In this study, we implement an experimental approach to partition the coral holobiont and resolve compartment- and taxa-specific responses in order to understand metaorganism function in coral disease.

  3. Estimate of carbonate production by scleractinian corals at Luhuitou fringing reef, Sanya, China

    Institute of Scientific and Technical Information of China (English)

    SHI Qi; ZHAO MeiXia; ZHANG QiaoMin; YU KeFu; CHEN TianRan; LI Shu; WANG HanKui

    2009-01-01

    Carbonate production by scleractinian corals not only maintains coral reef growth, but also represents an important source of atmospheric carbon dioxide. In this paper the carbonate production by scler-actinian corals at Luhuitou fringing reef, Sanya, Hainan Island, China, is investigated with an ecological census-based method. Averaged carbonate production is 1.16±0.55 kg·m-2·a-1 and 3.52±1.32 kg·m-2·a-1 on the reef flat and reef slope, respectively, depending on the composition and distribution of corals and the intergeneric difference of skeletal growth. In response to the rapidly increasing hu-man impacts, coral carbonate production has decreased by 80%-89% at this fringing reef since the 1960s; as a result, the reef accretion rate declined and became lower than the rate of sea level rise. Further development of the Luhuitou fringing reef will switch significantly from lateral extension sea-wards to vertical growth, reflecting a response of coral reef bio-geomorphic process to strong human impacts under the background of global sea level rise. In addition, decrease in coral carbonate pro-duction reduced CO2 release from this fringing reef. In the future, it is likely that the role played by coral reefs, especially of fringing reefs, in the ocean and even in the global carbon cycle will be modified or weakened by the increasing human impacts.

  4. Human disturbances on coral reefs in Sri Lanka: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, M.C.; Linden, O. (Stockholm Univ. (Sweden). Dept. of Zoology); Rajasuriya, A. (NARA, Crow Island, Colombo (Sri Lanka))

    1993-01-01

    The degradation of coral reefs in Sri Lanka has increased substantially over the last decades. Human activities causing this degradation include: mining for lime production, sewage discharges, discharges of oil and other pollutants in connection with shipping and port activities, destructive fishing practices, land and mangrove destruction, tourism and the collecting of fauna such as fish, shells and corals. In this study, three adjacent coral reefs; Bar Reef, Talawila Reef, and Kandakuliya Reef, which are widely scattered patch reefs off Kalpitiya Peninsula, northwestern Sri Lanka, were surveyed and compared in terms of their fish and coral diversity and abundance as well as human and natural disturbances. Information was gathered by snorkeling in visual overview surveys and by scuba diving in detailed transect surveys. When each reef was ranked according to the extent of live coral cover, and chaetodontid diversity, the results indicated that Bar Reef was in excellent condition, Talawila Reef was intermediate, and Kandakuliya Reef was in poor condition. The diversity of coral genera, the topographic relief and the proportion of coral rubble, did not follow the same pattern. The number of coral genera found was 49, while 283 fish species belonging to 51 families were recorded. Human disturbance factors on the reefs were found to be net fishing, boat anchoring and ornamental fish collection for the aquarium trade. Bottom.set nylon nets in particular were found to have a very destructive impact on the bottom fauna. 33 refs, 7 figs, 1 tab

  5. Coral-Bacterial Communities before and after a Coral Mass Spawning Event on Ningaloo Reef

    OpenAIRE

    Janja Ceh; Jean-Baptiste Raina; Soo, Rochelle M; Mike van Keulen; Bourne, David G.

    2012-01-01

    Bacteria associated with three coral species, Acropora tenuis, Pocillopora damicornis and Tubastrea faulkneri, were assessed before and after coral mass spawning on Ningaloo Reef in Western Australia. Two colonies of each species were sampled before and after the mass spawning event and two additional samples were collected for P. damicornis after planulation. A variable 470 bp region of the 16 S rRNA gene was selected for pyrosequencing to provide an understanding of potential variations in ...

  6. Diseases leading to accelerated decline of reef corals in the largest South Atlantic reef complex (Abrolhos Bank, eastern Brazil).

    Science.gov (United States)

    Francini-Filho, Ronaldo B; Moura, Rodrigo L; Thompson, Fabiano L; Reis, Rodrigo M; Kaufman, Les; Kikuchi, Ruy K P; Leão, Zelinda M A N

    2008-05-01

    Although reef corals worldwide have sustained epizootics in recent years, no coral diseases have been observed in the southwestern Atlantic Ocean until now. Here we present an overview of the main types of diseases and their incidence in the largest and richest coral reefs in the South Atlantic (Abrolhos Bank, eastern Brazil). Qualitative observations since the 1980s and regular monitoring since 2001 indicate that coral diseases intensified only recently (2005-2007). Based on estimates of disease prevalence and progression rate, as well as on the growth rate of a major reef-building coral species (the Brazilian-endemic Mussismilia braziliensis), we predict that eastern Brazilian reefs will suffer a massive coral cover decline in the next 50 years, and that M. braziliensis will be nearly extinct in less than a century if the current rate of mortality due to disease is not reversed. PMID:18348890

  7. A Trait-Based Approach to Advance Coral Reef Science.

    Science.gov (United States)

    Madin, Joshua S; Hoogenboom, Mia O; Connolly, Sean R; Darling, Emily S; Falster, Daniel S; Huang, Danwei; Keith, Sally A; Mizerek, Toni; Pandolfi, John M; Putnam, Hollie M; Baird, Andrew H

    2016-06-01

    Coral reefs are biologically diverse and ecologically complex ecosystems constructed by stony corals. Despite decades of research, basic coral population biology and community ecology questions remain. Quantifying trait variation among species can help resolve these questions, but progress has been hampered by a paucity of trait data for the many, often rare, species and by a reliance on nonquantitative approaches. Therefore, we propose filling data gaps by prioritizing traits that are easy to measure, estimating key traits for species with missing data, and identifying 'supertraits' that capture a large amount of variation for a range of biological and ecological processes. Such an approach can accelerate our understanding of coral ecology and our ability to protect critically threatened global ecosystems. PMID:26969335

  8. Performance Evaluation of CRW Reef-Scale and Broad-Scale SST-Based Coral Monitoring Products in Fringing Reef Systems of Tobago

    OpenAIRE

    Shaazia S. Mohammed; Heron, Scott F.; Rajindra Mahabir; Ricardo M. Clarke

    2015-01-01

    Satellite-derived sea surface temperature (SST) is used to monitor coral bleaching through the National Oceanic and Atmospheric Administration’s Coral Reef Watch (CRW) Decision Support System (DSS). Since 2000, a broad-scale 50 km SST was used to monitor thermal stress for coral reefs globally. However, some discrepancies were noted when applied to small-scale fringing coral reefs. To address this, CRW created a new DSS, specifically targeted at or near reef scales. Here, we evaluated the new...

  9. A coral-on-a-chip microfluidic platform enabling live-imaging microscopy of reef-building corals

    OpenAIRE

    Shapiro, Orr H.; Kramarsky-Winter, Esti; Gavish, Assaf R.; Stocker, Roman; Vardi, Assaf

    2016-01-01

    Coral reefs, and the unique ecosystems they support, are facing severe threats by human activities and climate change. Our understanding of these threats is hampered by the lack of robust approaches for studying the micro-scale interactions between corals and their environment. Here we present an experimental platform, coral-on-a-chip, combining micropropagation and microfluidics to allow direct microscopic study of live coral polyps. The small and transparent coral micropropagates are ideall...

  10. Coral reef soundscapes may not be detectable far from the reef

    Science.gov (United States)

    Kaplan, Maxwell B.; Mooney, T. Aran

    2016-01-01

    Biological sounds produced on coral reefs may provide settlement cues to marine larvae. Sound fields are composed of pressure and particle motion, which is the back and forth movement of acoustic particles. Particle motion (i.e., not pressure) is the relevant acoustic stimulus for many, if not most, marine animals. However, there have been no field measurements of reef particle motion. To address this deficiency, both pressure and particle motion were recorded at a range of distances from one Hawaiian coral reef at dawn and mid-morning on three separate days. Sound pressure attenuated with distance from the reef at dawn. Similar trends were apparent for particle velocity but with considerable variability. In general, average sound levels were low and perhaps too faint to be used as an orientation cue except very close to the reef. However, individual transient sounds that exceeded the mean values, sometimes by up to an order of magnitude, might be detectable far from the reef, depending on the hearing abilities of the larva. If sound is not being used as a long-range cue, it might still be useful for habitat selection or other biological activities within a reef. PMID:27550394

  11. Benthic communities at two remote Pacific coral reefs: effects of reef habitat, depth, and wave energy gradients on spatial patterns

    OpenAIRE

    Williams, Gareth J.; Jennifer E. Smith; Conklin, Eric J.; Gove, Jamison M.; Enric Sala; Sandin, Stuart A.

    2013-01-01

    Kingman Reef and Palmyra Atoll in the central Pacific are among the most remote coral reefs on the planet. Here we describe spatial patterns in their benthic communities across reef habitats and depths, and consider these in the context of oceanographic gradients. Benthic communities at both locations were dominated by calcifying organisms (54–86% cover), namely hard corals (20–74%) and crustose coralline algae (CCA) (10–36%). While turf algae were relatively common at both locations (8–22%),...

  12. Molecular reproductive characteristics of the reef coral Pocillopora damicornis.

    Science.gov (United States)

    Rougée, Luc R A; Richmond, Robert H; Collier, Abby C

    2015-11-01

    Coral reefs are an indispensible worldwide resource, accounting for billions of dollars in cultural, economic, and ecological services. An understanding of coral reproduction is essential to determining the effects of environmental stressors on coral reef ecosystems and their persistence into the future. Here, we describe the presence of and changes in steroidal hormones along with associated steroidogenic and steroid removal enzymes during the reproductive cycle of the brooding, pan-Pacific, hermaphroditic coral, Pocillopora damicornis. Detectable levels of 17β-estradiol, estrone, progesterone and testosterone were consistently detected over two consecutive lunar reproductive cycles in coral tissue. Intra-colony variation in steroid hormone levels ranged between 1.5- and 2.2-fold and were not statistically different. Activities of the steroidogenic enzymes 3β-hydroxysteroid dehydrogenase and cytochrome P450 (CYP) 17 dehydrogenase were detectable and did not fluctuate over the reproductive cycle. Aromatase-like activity was detected during the lunar reproductive cycle with no significant fluctuations. Activities of regeneration enzymes did not fluctuate over the lunar cycle; however, activity of the clearance enzyme UDP-glucuronosyl transferases increased significantly (ANOVA, post hoc p<0.01) during the two weeks before and after peak larval release (planulation), suggesting that the activity of this enzyme family may be linked to the reproductive state of the coral. Sulfotransferase enzymes could not be detected. Our findings provide the first data defining normal physiological and lunar/reproductive variability in steroidal enzymes in a coral species with respect to their potential role in coral reproduction. PMID:26231839

  13. Multisensor and Multitemporal Data from Landsat Images to Detect Damage to Coral Reefs, Small Islands in the Spermonde Archipelago, Indonesia

    OpenAIRE

    Nurdin, Nurjannah

    2015-01-01

    Coral reefs are important because of their high biodiversity and their key role in the tropical marine biosphere. Furthermore, coral reefs are very valuable as a socioeconomic resource as they make important contributions to the gross domestic product of many countries. Thus, it is very important to monitor dynamic spatial distributions of coral reefs and related habitats dominated by coral rubble, dead coral, and bleached corals. Despite these natural and socio-economic ...

  14. Catchment management and the Great Barrier Reef.

    Science.gov (United States)

    Brodie, J; Christie, C; Devlin, M; Haynes, D; Morris, S; Ramsay, M; Waterhouse, J; Yorkston, H

    2001-01-01

    Pollution of coastal regions of the Great Barrier Reef is dominated by runoff from the adjacent catchment. Catchment land-use is dominated by beef grazing and cropping, largely sugarcane cultivation, with relatively minor urban development. Runoff of sediment, nutrients and pesticides is increasing and for nitrogen is now four times the natural amount discharged 150 years ago. Significant effects and potential threats are now evident on inshore reefs, seagrasses and marine animals. There is no effective legislation or processes in place to manage agricultural pollution. The Great Barrier Reef Marine Park Act does not provide effective jurisdiction on the catchment. Queensland legislation relies on voluntary codes and there is no assessment of the effectiveness of the codes. Integrated catchment management strategies, also voluntary, provide some positive outcomes but are of limited success. Pollutant loads are predicted to continue to increase and it is unlikely that current management regimes will prevent this. New mechanisms to prevent continued degradation of inshore ecosystems of the Great Barrier Reef World Heritage Area are urgently needed. PMID:11419129

  15. Monitoring Coral Health to Determine Coral Bleaching Response at High Latitude Eastern Australian Reefs: An Applied Model for A Changing Climate

    Directory of Open Access Journals (Sweden)

    Andrew G. Carroll

    2011-09-01

    Full Text Available Limited information is available on the bleaching susceptibility of coral species that dominate high latitude reefs along the eastern seaboard of Australia. The main aims of this study were to: (i monitor coral health and spatial patterns of coral bleaching response at the Solitary Islands Marine Park (SIMP and Lord Howe Island Marine Park (LHIMP, to determine variability of bleaching susceptibility among coral taxa; (ii predict coral bleaching thresholds at 30 °S and 31.5 °S, extrapolated from published bleaching threshold data; and (iii propose a subtropical northern New South Wales coral bleaching model from biological and physical data. Between 2005 and 2007 minor bleaching was observed in dominant coral families including Pocilloporidae, Poritidae and Dendrophylliidae in the SIMP and Pocilloporidae, Poritidae and Acroporidae (Isopora and Montipora spp. in the LHIMP, with a clear difference in bleaching susceptibility found between sites, both within and between locations. Bleaching susceptibility was highest in Porites spp. at the most offshore island site within the SIMP during summer 2005. Patterns of subtropical family bleaching susceptibility within the SIMP and LHIMP differed to those previously reported for the central Great Barrier Reef (GBR. These differences may be due to a number of factors, including temperature history and/or the coral hosts association with different zooxanthellae clades, which may have lower thermal tolerances. An analysis of published estimates of coral bleaching thresholds from the Caribbean, South Africa, GBR and central and northern Pacific regions suggests that the bleaching threshold at 30–31.5 °S ranges between 26.5–26.8 °C. This predicted threshold was confirmed by an extensive coral bleaching event on the world’s southernmost coral reef at Lord Howe Island, during the 2010 austral summer season. These results imply that dominant coral taxa at subtropical reefs along the eastern Australian

  16. The state of coral reef ecosystems of the United States and Pacific Freely Associated States: 2008

    OpenAIRE

    2008-01-01

    In the past decade, increased awareness regarding the declining condition of U.S. coral reefs has prompted various actions by governmental and non-governmental organizations. Presidential Executive Order 13089 created the U.S. Coral Reef Task Force (USCRTF) in 1998 to coordinate federal and state/territorial activities (Clinton, 1998), and the Coral Reef Conservation Act of 2000 provided Congressional funding for activities to conserve these important ecosystems, including mapping, monitoring...

  17. Responses of Cryptofaunal Species Richness and Trophic Potential to Coral Reef Habitat Degradation

    OpenAIRE

    Manzello, Derek P.; Enochs, Ian C.

    2012-01-01

    Coral reefs are declining worldwide as a result of many anthropogenic disturbances. This trend is alarming because coral reefs are hotspots of marine biodiversity and considered the ‘rainforests of the sea. As in the rainforest, much of the diversity on a coral reef is cryptic, remaining hidden among the cracks and crevices of structural taxa. Although the cryptofauna make up the majority of a reef’s metazoan biodiversity, we know little about their basic ecology or how these communities resp...

  18. Study on coral reef fishes diversity of Kambing Island, Madura Strait, East Java, Indonesia

    OpenAIRE

    Sumadhiharga, Ono Kurnaen

    2006-01-01

    Research on diversity of coral reef fishes of Kambing Island, Madura Strait, East Java, Indonesia was conducted in July 2002. The coral reef fishes are divided into three categories; major fishes consisted of 63 species of 13 families, target fishes 29 species of eight families, and indicator fishes eight species of only one family (Chaetodontidae). In general, the average abundance of the coral reef fishes in the study site is six individuals per square meter. The dominant indicator species ...

  19. Controls on Coral-Ground Development along the Northern Mesoamerican Reef Tract

    OpenAIRE

    Rodríguez-Martínez, Rosa E.; Jordán-Garza, Adán G.; Maldonado, Miguel A.; Blanchon, Paul

    2011-01-01

    Coral-grounds are reef communities that colonize rocky substratum but do not form framework or three-dimensional reef structures. To investigate why, we used video transects and underwater photography to determine the composition, structure and status of a coral-ground community located on the edge of a rocky terrace in front of a tourist park, Xcaret, in the northern Mesoamerican Reef tract, Mexico. The community has a relatively low coral, gorgonian and sponge cover (40%). We recorded 23 sp...

  20. Coral reef ecosystem services economic valuation experiences from the South Pacific

    OpenAIRE

    Pascal, Nicolas

    2013-01-01

    Economic approaches through ecosystem services (ES) valuation are increasingly recommended by conservation organisations to face main market externalities affecting biodiversity in general and coral reef ecosystems. In this dissertation, we will analyse the experience of two economic valuations of coral reef ecosystems in the Pacific focusing on two aspects. The first is to evaluate if current methods of Coral Reef Ecosystem Services Valuation (CRESV) permits to transmit a correct signal abou...

  1. Reef-coral refugia in a rapidly changing ocean.

    Science.gov (United States)

    Cacciapaglia, Chris; van Woesik, Robert

    2015-06-01

    This study sought to identify climate-change thermal-stress refugia for reef corals in the Indian and Pacific Oceans. A species distribution modeling approach was used to identify refugia for 12 coral species that differed considerably in their local response to thermal stress. We hypothesized that the local response of coral species to thermal stress might be similarly reflected as a regional response to climate change. We assessed the contemporary geographic range of each species and determined their temperature and irradiance preferences using a k-fold algorithm to randomly select training and evaluation sites. That information was applied to downscaled outputs of global climate models to predict where each species is likely to exist by the year 2100. Our model was run with and without a 1°C capacity to adapt to the rising ocean temperature. The results show a positive exponential relationship between the current area of habitat that coral species occupy and the predicted area of habitat that they will occupy by 2100. There was considerable decoupling between scales of response, however, and with further ocean warming some 'winners' at local scales will likely become 'losers' at regional scales. We predicted that nine of the 12 species examined will lose 24-50% of their current habitat. Most reductions are predicted to occur between the latitudes 5-15°, in both hemispheres. Yet when we modeled a 1°C capacity to adapt, two ubiquitous species, Acropora hyacinthus and Acropora digitifera, were predicted to retain much of their current habitat. By contrast, the thermally tolerant Porites lobata is expected to increase its current distribution by 14%, particularly southward along the east and west coasts of Australia. Five areas were identified as Indian Ocean refugia, and seven areas were identified as Pacific Ocean refugia for reef corals under climate change. All 12 of these reef-coral refugia deserve high-conservation status. PMID:25646684

  2. Dynamics and diversity of phosphate mineralizing bacteria in the coral reefs of Gulf of Mannar

    Digital Repository Service at National Institute of Oceanography (India)

    Kannapiran, E.; Ravindran, J.

    Phosphatase Producing Bacteria (PPB) and Inorganic Phosphate Solubilizing Bacteria (IPSB) are important to reef nutrition. These microbes and phosphate concentration play a significant role in the productivity of coral reef ecosystems. A study...

  3. American Samoa: coral reef monitoring interactive map and information layers primarily from 2010 surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This interactive map displays American Samoa data collected by the NOAA Coral Reef Ecosystem Division (CRED) during the Pacific Reef Assessment and Monitoring...

  4. Coral Reef Bleaching at Agatti Island of Lakshadweep Atolls, India

    Institute of Scientific and Technical Information of China (English)

    Ramar Vinoth; Mohan Gopi; Thipramalai Thankappanpillai Ajith Kumar; Thirunavukarassu Thangaradjou; Thangavel Balasubramanian

    2012-01-01

    A survey on coral bleaching was carried out at Agatti Island of Lakshadweep from May to June 2010.Elevated sea surface temperatures (SSTs) of the region exceeded the seasonal average and delayed the onset of monsoon,which triggered widespread bleaching of corals.The Agatti reefs showed an average of 73% bleached corals with apparent bleaching-related mortality of sea anemones (87%) and giant clams (83%).The SST increased up to 34 ℃ with an average maximum SST of 32.5℃ during the study period between May and June 2010.Coral reefs on the southern side of the island are fully or partially exposed to sun light during low tide in contrast to the other side.This suggests that the mortality is more likely due to the low tide exposure than exclusively due to the elevated SST.Observations indicated a clear increase in coral bleaching during April 2010,at levels higher than that in normal summer.

  5. Multi-locus sequence data reveal a new species of coral reef goby (Teleostei: Gobiidae: Eviota), and evidence of Pliocene vicariance across the Coral Triangle.

    Science.gov (United States)

    Tornabene, L; Valdez, S; Erdmann, M V; Pezold, F L

    2016-05-01

    Here, multi-locus sequence data are coupled with observations of live colouration to recognize a new species, Eviota punyit from the Coral Triangle, Indian Ocean and Red Sea. Relaxed molecular clock divergence time estimation indicates a Pliocene origin for the new species, and the current distribution of the new species and its sister species Eviota sebreei supports a scenario of vicariance across the Indo-Pacific Barrier, followed by subsequent range expansion and overlap in the Coral Triangle. These results are consistent with the 'centre of overlap' hypothesis, which states that the increased diversity in the Coral Triangle is due in part to the overlapping ranges of Indian Ocean and Pacific Ocean faunas. These findings are discussed in the context of other geminate pairs of coral reef fishes separated by the Indo-Pacific Barrier. PMID:27021219

  6. Reef fish and coral assemblages at Maptaput, Rayong Province

    Directory of Open Access Journals (Sweden)

    Voravit Cheevaporn

    2007-06-01

    Full Text Available This study describes the structure of coral and fish assemblages of a group of small islands and pinnacles in the vicinity of Maptaput deep sea port, Rayong Province, Thailand during 2002. The coral and fish assemblages at Saket Island and nearby pinnacle, Hin-Yai, which are located less than 1 km from the deep sea port, had changed. Living coral cover in 2002 was 8% at Hin-Yai and 4% at Saket Island which decreased from 33% and 64%, respectively in the previous report in 1992. Numbers of coral species at Saket Island decreased from 41 species to 13 species. Acropora spp. that previously dominated the area had nearly disappeared. For fishes, a total of 40 species were found in 2002 the numbers decreased to only 6 species at Saket Island and 36 species at Hin-Yai. Fishes that dominated the area are small pomacentrids. After 1997, the conditions of coral and fish assemblages at Saket Island and Hin-Yai had markedly changed, whereas, the conditions found in the nearby area are much better. Sediment load from port construction was the primary cause of the degradation. This should indicate the adverse effect of sedimentation on coral and reef fish assemblages at Maptaput. Coral communities developed on rock pinnacles west of Maptaput deep-sea port are reported and described herein for the first time.

  7. Atlantis Modeled Output Data for the Coral Reef Ecosystems of Guam

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A proof-of-concept Guam Atlantis Coral Reef Ecosystem Model has been developed and an added coral module to the Atlantis framework has been validated. The model is...

  8. Rapid transition in the structure of a coral reef community: The effects of coral bleaching and physical disturbance

    OpenAIRE

    Ostrander, Gary K.; Armstrong, Kelley Meyer; Knobbe, Edward T.; Gerace, Donald; Scully, Erik P.

    2000-01-01

    Coral reef communities are in a state of change throughout their geographical range. Factors contributing to this change include bleaching (the loss of algal symbionts), storm damage, disease, and increasing abundance of macroalgae. An additional factor for Caribbean reefs is the aftereffects of the epizootic that reduced the abundance of the herbivorous sea urchin, Diadema antillarum. Although coral reef communities have undergone phase shifts, there are few studies that document the details...

  9. Temporal comparison and predictors of fish species abundance and richness on undisturbed coral reef patches

    OpenAIRE

    Wagner, Elena L.E.S.; Roche, Dominique G.; Binning, Sandra A.; Wismer, Sharon; Bshary, Redouan

    2015-01-01

    Large disturbances can cause rapid degradation of coral reef communities, but what baseline changes in species assemblages occur on undisturbed reefs through time? We surveyed live coral cover, reef fish abundance and fish species richness in 1997 and again in 2007 on 47 fringing patch reefs of varying size and depth at Mersa Bareika, Ras Mohammed National Park, Egypt. No major human or natural disturbance event occurred between these two survey periods in this remote protected area. In the a...

  10. A geological perspective on the degradation and conservation of western Atlantic coral reefs.

    Science.gov (United States)

    Kuffner, Ilsa B; Toth, Lauren T

    2016-08-01

    Continuing coral-reef degradation in the western Atlantic is resulting in loss of ecological and geologic functions of reefs. With the goal of assisting resource managers and stewards of reefs in setting and measuring progress toward realistic goals for coral-reef conservation and restoration, we examined reef degradation in this region from a geological perspective. The importance of ecosystem services provided by coral reefs-as breakwaters that dissipate wave energy and protect shorelines and as providers of habitat for innumerable species-cannot be overstated. However, the few coral species responsible for reef building in the western Atlantic during the last approximately 1.5 million years are not thriving in the 21st century. These species are highly sensitive to abrupt temperature extremes, prone to disease infection, and have low sexual reproductive potential. Their vulnerability and the low functional redundancy of branching corals have led to the low resilience of western Atlantic reef ecosystems. The decrease in live coral cover over the last 50 years highlights the need for study of relict (senescent) reefs, which, from the perspective of coastline protection and habitat structure, may be just as important to conserve as the living coral veneer. Research is needed to characterize the geological processes of bioerosion, reef cementation, and sediment transport as they relate to modern-day changes in reef elevation. For example, although parrotfish remove nuisance macroalgae, possibly promoting coral recruitment, they will not save Atlantic reefs from geological degradation. In fact, these fish are quickly nibbling away significant quantities of Holocene reef framework. The question of how different biota covering dead reefs affect framework resistance to biological and physical erosion needs to be addressed. Monitoring and managing reefs with respect to physical resilience, in addition to ecological resilience, could optimize the expenditure of resources

  11. Mapping Coral Reef Resilience Indicators Using Field and Remotely Sensed Data

    OpenAIRE

    Stuart Phinn; Mitchell Lyons; Chris Roelfsema; Stacy Jupiter; Anders Knudby

    2013-01-01

    In the face of increasing climate-related impacts on coral reefs, the integration of ecosystem resilience into marine conservation planning has become a priority. One strategy, including resilient areas in marine protected area (MPA) networks, relies on information on the spatial distribution of resilience. We assess the ability to model and map six indicators of coral reef resilience—stress-tolerant coral taxa, coral generic diversity, fish herbivore biomass, fish herbivore functional group ...

  12. Boring sponges, an increasing threat for coral reefs affected by bleaching events

    OpenAIRE

    Carballo, José L; Bautista, Eric; Nava, Héctor; Cruz-Barraza, José A; Chávez, Jesus A

    2013-01-01

    Coral bleaching is a stress response of corals induced by a variety of factors, but these events have become more frequent and intense in response to recent climate-change-related temperature anomalies. We tested the hypothesis that coral reefs affected by bleaching events are currently heavily infested by boring sponges, which are playing a significant role in the destruction of their physical structure. Seventeen reefs that cover the entire distributional range of corals along the Mexican P...

  13. Overfishing and nutrient pollution interact with temperature to disrupt coral reefs down to microbial scales

    OpenAIRE

    Zaneveld, Jesse R.; Burkepile, Deron E.; Shantz, Andrew A.; Pritchard, Catharine E.; McMinds, Ryan; Payet, Jérôme P.; Welsh, Rory; Correa, Adrienne M. S.; Nathan P Lemoine; Rosales, Stephanie; Fuchs, Corinne; Maynard, Jeffrey A; Thurber, Rebecca Vega

    2016-01-01

    International audience Losses of corals worldwide emphasize the need to understand what drives reef decline. Stressors such as overfishing and nutrient pollution may reduce resilience of coral reefs by increasing coral–algal competition and reducing coral recruitment, growth and survivorship. Such effects may themselves develop via several mechanisms, including disruption of coral microbiomes. Here we report the results of a 3-year field experiment simulating overfishing and nutrient pollu...

  14. Coping with Commitment: Projected Thermal Stress on Coral Reefs under Different Future Scenarios

    OpenAIRE

    Donner, Simon D.

    2009-01-01

    BACKGROUND: Periods of anomalously warm ocean temperatures can lead to mass coral bleaching. Past studies have concluded that anthropogenic climate change may rapidly increase the frequency of these thermal stress events, leading to declines in coral cover, shifts in the composition of corals and other reef-dwelling organisms, and stress on the human populations who depend on coral reef ecosystems for food, income and shoreline protection. The ability of greenhouse gas mitigation to alter the...

  15. Testing animal-assisted cleaning prior to transplantation in coral reef restoration

    OpenAIRE

    Frias-Torres, Sarah; van de Geer, Casper

    2015-01-01

    Rearing coral fragments in nurseries and subsequent transplantation onto a degraded reef is a common approach for coral reef restoration. However, if barnacles and other biofouling organisms are not removed prior to transplantation, fish will dislodge newly cemented corals when feeding on biofouling organisms. This behavior can lead to an increase in diver time due to the need to reattach the corals. Thus, cleaning nurseries to remove biofouling organisms such as algae and invertebrates is ne...

  16. Monitoring of heavy metal partitioning in reef corals of Lakshadweep Archipelago, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Anu, G.; Kumar, N.C.; Jayalakshmy, K.V.; Nair, S.M.

    . In Lakshadweep, local life is very much dependent on the reefs and its resources. From this point of view, it be- comes important to quantify the level of heavy metal pollutants on reef corals because it is likely that any ad- verse effect on corals... (63%). In L. corymbosa and in A. Formosa, the preferential enrichment of Cu was in the tissue phase. The effect of copper on scleractinian corals is of environmental concern because there are numerous sources of copper to coral reefs, and corals...

  17. Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals

    Directory of Open Access Journals (Sweden)

    Tse-Lynn Loh

    2015-04-01

    Full Text Available Consumer-mediated indirect effects at the community level are difficult to demonstrate empirically. Here, we show an explicit indirect effect of overfishing on competition between sponges and reef-building corals from surveys of 69 sites across the Caribbean. Leveraging the large-scale, long-term removal of sponge predators, we selected overfished sites where intensive methods, primarily fish-trapping, have been employed for decades or more, and compared them to sites in remote or marine protected areas (MPAs with variable levels of enforcement. Sponge-eating fishes (angelfishes and parrotfishes were counted at each site, and the benthos surveyed, with coral colonies scored for interaction with sponges. Overfished sites had >3 fold more overgrowth of corals by sponges, and mean coral contact with sponges was 25.6%, compared with 12.0% at less-fished sites. Greater contact with corals by sponges at overfished sites was mostly by sponge species palatable to sponge predators. Palatable species have faster rates of growth or reproduction than defended sponge species, which instead make metabolically expensive chemical defenses. These results validate the top-down conceptual model of sponge community ecology for Caribbean reefs, as well as provide an unambiguous justification for MPAs to protect threatened reef-building corals. An unanticipated outcome of the benthic survey component of this study was that overfished sites had lower mean macroalgal cover (23.1% vs. 38.1% for less-fished sites, a result that is contrary to prevailing assumptions about seaweed control by herbivorous fishes. Because we did not quantify herbivores for this study, we interpret this result with caution, but suggest that additional large-scale studies comparing intensively overfished and MPA sites are warranted to examine the relative impacts of herbivorous fishes and urchins on Caribbean reefs.

  18. Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals.

    Science.gov (United States)

    Loh, Tse-Lynn; McMurray, Steven E; Henkel, Timothy P; Vicente, Jan; Pawlik, Joseph R

    2015-01-01

    Consumer-mediated indirect effects at the community level are difficult to demonstrate empirically. Here, we show an explicit indirect effect of overfishing on competition between sponges and reef-building corals from surveys of 69 sites across the Caribbean. Leveraging the large-scale, long-term removal of sponge predators, we selected overfished sites where intensive methods, primarily fish-trapping, have been employed for decades or more, and compared them to sites in remote or marine protected areas (MPAs) with variable levels of enforcement. Sponge-eating fishes (angelfishes and parrotfishes) were counted at each site, and the benthos surveyed, with coral colonies scored for interaction with sponges. Overfished sites had >3 fold more overgrowth of corals by sponges, and mean coral contact with sponges was 25.6%, compared with 12.0% at less-fished sites. Greater contact with corals by sponges at overfished sites was mostly by sponge species palatable to sponge predators. Palatable species have faster rates of growth or reproduction than defended sponge species, which instead make metabolically expensive chemical defenses. These results validate the top-down conceptual model of sponge community ecology for Caribbean reefs, as well as provide an unambiguous justification for MPAs to protect threatened reef-building corals. An unanticipated outcome of the benthic survey component of this study was that overfished sites had lower mean macroalgal cover (23.1% vs. 38.1% for less-fished sites), a result that is contrary to prevailing assumptions about seaweed control by herbivorous fishes. Because we did not quantify herbivores for this study, we interpret this result with caution, but suggest that additional large-scale studies comparing intensively overfished and MPA sites are warranted to examine the relative impacts of herbivorous fishes and urchins on Caribbean reefs. PMID:25945305

  19. Ecological States and the Resilience of Coral Reefs

    Directory of Open Access Journals (Sweden)

    Terry Done

    2002-12-01

    Full Text Available We review the evidence for multiple ecological states and the factors that create ecological resilience in coral reef ecosystems. There are natural differences among benthic communities along gradients of water temperature, light, nutrients, and organic matter associated with upwelling-downwelling and onshore-offshore systems. Along gradients from oligotrophy to eutrophy, plant-animal symbioses tend to decrease, and the abundance of algae and heterotrophic suspension feeders and the ratio of organic to inorganic carbon production tend to increase. Human influences such as fishing, increased organic matter and nutrients, sediments, warm water, and transportation of xenobiotics and diseases are common causes of a large number of recently reported ecological shifts. It is often the interaction of persistent and multiple synergistic disturbances that causes permanent ecological transitions, rather than the succession of individual short-term disturbances. For example, fishing can remove top-level predators, resulting in the ecological release of prey such as sea urchins and coral-eating invertebrates. When sea urchins are not common because of unsuitable habitat, recruitment limitations, and diseases, and when overfishing removes herbivorous fish, frondose brown algae can dominate. Terrigenous sediments carried onto reefs as a result of increased soil erosion largely promote the dominance of turf or articulated green algae. Elevated nutrients and organic matter can increase internal eroders of reef substratum and a mixture of filamentous algae. Local conservation actions that attempt to reduce fishing and terrestrial influences promote the high production of inorganic carbon that is necessary for reef growth. However, global climate change threatens to undermine such actions because of increased bleaching and mortality caused by warm-water anomalies, weakened coral skeletons caused by reduced aragonite availability in reef waters, and increased

  20. Environmentally controlled succession in a late Pleistocene coral reef (Sinai, Egypt)

    Science.gov (United States)

    Mewis, H.; Kiessling, W.

    2013-03-01

    The concept of ecological succession has been frequently applied in the study of ancient reefs. Whereas Paleozoic and Mesozoic reefs are commonly thought to reveal an autogenic primary—climax zonation, patterns in Neogene and Quaternary reefs are much more diverse. Here, we describe a well-preserved late Pleistocene coral reef from Dahab on Sinai Peninsula (Egypt), which shows a distinct zonation that resembles an ecological succession. In contrast to classical examples of ecological successions, species composition, paleoenvironmental conditions, and coral biodiversity of the Dahab reef indicate an allogenic, sea-level controlled community change, from marginal marine to reef slope and back reef. A review of the literature confirms that autogenic, short-term successions are virtually absent in Quaternary reefs. We predict that long generation times of corals make it unlikely that classical autogenic successions develop in reefs at all, unless environmental conditions are unusually stable.

  1. A robust operational model for predicting where tropical cyclone waves damage coral reefs

    Science.gov (United States)

    Puotinen, Marji; Maynard, Jeffrey A.; Beeden, Roger; Radford, Ben; Williams, Gareth J.

    2016-05-01

    Tropical cyclone (TC) waves can severely damage coral reefs. Models that predict where to find such damage (the ‘damage zone’) enable reef managers to: 1) target management responses after major TCs in near-real time to promote recovery at severely damaged sites; and 2) identify spatial patterns in historic TC exposure to explain habitat condition trajectories. For damage models to meet these needs, they must be valid for TCs of varying intensity, circulation size and duration. Here, we map damage zones for 46 TCs that crossed Australia’s Great Barrier Reef from 1985–2015 using three models – including one we develop which extends the capability of the others. We ground truth model performance with field data of wave damage from seven TCs of varying characteristics. The model we develop (4MW) out-performed the other models at capturing all incidences of known damage. The next best performing model (AHF) both under-predicted and over-predicted damage for TCs of various types. 4MW and AHF produce strikingly different spatial and temporal patterns of damage potential when used to reconstruct past TCs from 1985–2015. The 4MW model greatly enhances both of the main capabilities TC damage models provide to managers, and is useful wherever TCs and coral reefs co-occur.

  2. A robust operational model for predicting where tropical cyclone waves damage coral reefs

    Science.gov (United States)

    Puotinen, Marji; Maynard, Jeffrey A.; Beeden, Roger; Radford, Ben; Williams, Gareth J.

    2016-01-01

    Tropical cyclone (TC) waves can severely damage coral reefs. Models that predict where to find such damage (the ‘damage zone’) enable reef managers to: 1) target management responses after major TCs in near-real time to promote recovery at severely damaged sites; and 2) identify spatial patterns in historic TC exposure to explain habitat condition trajectories. For damage models to meet these needs, they must be valid for TCs of varying intensity, circulation size and duration. Here, we map damage zones for 46 TCs that crossed Australia’s Great Barrier Reef from 1985–2015 using three models – including one we develop which extends the capability of the others. We ground truth model performance with field data of wave damage from seven TCs of varying characteristics. The model we develop (4MW) out-performed the other models at capturing all incidences of known damage. The next best performing model (AHF) both under-predicted and over-predicted damage for TCs of various types. 4MW and AHF produce strikingly different spatial and temporal patterns of damage potential when used to reconstruct past TCs from 1985–2015. The 4MW model greatly enhances both of the main capabilities TC damage models provide to managers, and is useful wherever TCs and coral reefs co-occur. PMID:27184607

  3. A robust operational model for predicting where tropical cyclone waves damage coral reefs.

    Science.gov (United States)

    Puotinen, Marji; Maynard, Jeffrey A; Beeden, Roger; Radford, Ben; Williams, Gareth J

    2016-01-01

    Tropical cyclone (TC) waves can severely damage coral reefs. Models that predict where to find such damage (the 'damage zone') enable reef managers to: 1) target management responses after major TCs in near-real time to promote recovery at severely damaged sites; and 2) identify spatial patterns in historic TC exposure to explain habitat condition trajectories. For damage models to meet these needs, they must be valid for TCs of varying intensity, circulation size and duration. Here, we map damage zones for 46 TCs that crossed Australia's Great Barrier Reef from 1985-2015 using three models - including one we develop which extends the capability of the others. We ground truth model performance with field data of wave damage from seven TCs of varying characteristics. The model we develop (4MW) out-performed the other models at capturing all incidences of known damage. The next best performing model (AHF) both under-predicted and over-predicted damage for TCs of various types. 4MW and AHF produce strikingly different spatial and temporal patterns of damage potential when used to reconstruct past TCs from 1985-2015. The 4MW model greatly enhances both of the main capabilities TC damage models provide to managers, and is useful wherever TCs and coral reefs co-occur. PMID:27184607

  4. Density-associated recruitment mediates coral population dynamics on a coral reef

    Science.gov (United States)

    Bramanti, Lorenzo; Edmunds, Peter J.

    2016-06-01

    Theory suggests that density-associated processes can modulate community resilience following declines in population size. Here, we demonstrate density-associated processes in two scleractinian populations on the outer reef of Moorea, French Polynesia, that are rapidly increasing in size following the effects of two catastrophic disturbances. Between 2006 and 2010, predation by the corallivorous crown-of-thorns sea star reduced coral cover by 93 %; in 2010, the dead coral skeletons were removed by a cyclone, and in 2011 and 2012, high coral recruitment initiated population recovery. Coral recruitment was associated with coral cover, but the relationship differed between two coral genera that are almost exclusively broadcast spawners in Moorea. Acroporids recruited at low densities, and the density of recruits was positively associated with cover of Acropora, whereas pocilloporids recruited at high densities, and densities of their recruits were negatively associated with cover of Pocillopora. Together, our results suggest that associations between adult cover and density of both juveniles and recruits can mediate rapid coral community recovery after large disturbances. The difference between taxa in sign of the relationships between recruit density and coral cover indicate that they reflect contrasting mechanisms with the potential to mediate temporal shifts in taxonomic composition of coral communities.

  5. Relating sediment impacts on coral reefs to watershed sources, processes and management: a review.

    Science.gov (United States)

    Bartley, Rebecca; Bainbridge, Zoe T; Lewis, Stephen E; Kroon, Frederieke J; Wilkinson, Scott N; Brodie, Jon E; Silburn, D Mark

    2014-01-15

    Modification of terrestrial sediment fluxes can result in increased sedimentation and turbidity in receiving waters, with detrimental impacts on coral reef ecosystems. Preventing anthropogenic sediment reaching coral reefs requires a better understanding of the specific characteristics, sources and processes generating the anthropogenic sediment, so that effective watershed management strategies can be implemented. Here, we review and synthesise research on measured runoff, sediment erosion and sediment delivery from watersheds to near-shore marine areas, with a strong focus on the Burdekin watershed in the Great Barrier Reef region, Australia. We first investigate the characteristics of sediment that pose the greatest risk to coral reef ecosystems. Next we track this sediment back from the marine system into the watershed to determine the storage zones, source areas and processes responsible for sediment generation and run-off. The review determined that only a small proportion of the sediment that has been eroded from the watershed makes it to the mid and outer reefs. The sediment transported >1 km offshore is generally the clay to fine silt (sediment fractions (sediments is still under investigation; however, the Bowen, Upper Burdekin and Lower Burdekin sub-watersheds appear to be the dominant source of the clay and fine silt fractions. Sub-surface erosion is the dominant process responsible for the fine sediment exported from these watersheds in recent times, although further work on the particle size of this material is required. Maintaining average minimum ground cover >75% will likely be required to reduce runoff and prevent sub-soil erosion; however, it is not known whether ground cover management alone will reduce sediment supply to ecologically acceptable levels. PMID:24121565

  6. Conservation Planning for Coral Reefs Accounting for Climate Warming Disturbances

    OpenAIRE

    Magris, Rafael A.; Heron, Scott F.; Robert L. Pressey

    2015-01-01

    Incorporating warming disturbances into the design of marine protected areas (MPAs) is fundamental to developing appropriate conservation actions that confer coral reef resilience. We propose an MPA design approach that includes spatially- and temporally-varying sea-surface temperature (SST) data, integrating both observed (1985–2009) and projected (2010–2099) time-series. We derived indices of acute (time under reduced ecosystem function following short-term events) and chronic thermal stres...

  7. Is climate change triggering coral bleaching in tropical reef?

    Digital Repository Service at National Institute of Oceanography (India)

    Kalyan, De; Sautya, S.; Mote, S.; Tsering, L.; Patil, V.; Nagesh, R.; Ingole, B.S.

    & Marine Chemicals Research Institute, Mandpam Camp 623 519, India e-mail: vaibhav@csmcri.org Is climate change triggering coral bleaching in tropical reef? Elevated sea-surface temperatures (SST) caused by global warming is having seri- ous... and to also undertake complete digitiza- tion of its collection for database and Figure 1. View of compactors housing herbarium sheets. linking it to leading global biodiversity databases. We are in process of obtaining recognition from National...

  8. Spot the Difference: Mimicry in a Coral Reef Fish

    OpenAIRE

    Gagliano, Monica; Depczynski, Martial

    2013-01-01

    Eyespots on the body of many animals have long been assumed to confer protection against predators, but empirical evidence has recently demonstrated that this may not always be the case and suggested that such markings may also serve other purposes. Clearly, this raises the unresolved question of what functions do these markings have and do they contribute to an individual’s evolutionary fitness in the wild. Here, we examined the occurrence of eyespots on the dorsal fin of a coral reef damsel...

  9. Invasive Lionfish Drive Atlantic Coral Reef Fish Declines

    OpenAIRE

    Green, Stephanie J.; John L Akins; Aleksandra Maljković; Isabelle M. Côté

    2012-01-01

    Indo-Pacific lionfish (Pterois volitans and P. miles) have spread swiftly across the Western Atlantic, producing a marine predator invasion of unparalleled speed and magnitude. There is growing concern that lionfish will affect the structure and function of invaded marine ecosystems, however detrimental impacts on natural communities have yet to be measured. Here we document the response of native fish communities to predation by lionfish populations on nine coral reefs off New Providence Isl...

  10. Overfishing and nutrient pollution interact with temperature to disrupt coral reefs down to microbial scales.

    Science.gov (United States)

    Zaneveld, Jesse R; Burkepile, Deron E; Shantz, Andrew A; Pritchard, Catharine E; McMinds, Ryan; Payet, Jérôme P; Welsh, Rory; Correa, Adrienne M S; Lemoine, Nathan P; Rosales, Stephanie; Fuchs, Corinne; Maynard, Jeffrey A; Thurber, Rebecca Vega

    2016-01-01

    Losses of corals worldwide emphasize the need to understand what drives reef decline. Stressors such as overfishing and nutrient pollution may reduce resilience of coral reefs by increasing coral-algal competition and reducing coral recruitment, growth and survivorship. Such effects may themselves develop via several mechanisms, including disruption of coral microbiomes. Here we report the results of a 3-year field experiment simulating overfishing and nutrient pollution. These stressors increase turf and macroalgal cover, destabilizing microbiomes, elevating putative pathogen loads, increasing disease more than twofold and increasing mortality up to eightfold. Above-average temperatures exacerbate these effects, further disrupting microbiomes of unhealthy corals and concentrating 80% of mortality in the warmest seasons. Surprisingly, nutrients also increase bacterial opportunism and mortality in corals bitten by parrotfish, turning normal trophic interactions deadly for corals. Thus, overfishing and nutrient pollution impact reefs down to microbial scales, killing corals by sensitizing them to predation, above-average temperatures and bacterial opportunism. PMID:27270557

  11. A geological perspective on the degradation and conservation of western Atlantic coral reefs

    Science.gov (United States)

    Kuffner, Ilsa B.; Toth, Lauren

    2016-01-01

    Continuing coral-reef degradation in the western Atlantic is resulting in loss of ecological and geologic functions of reefs. With the goal of assisting resource managers and stewards of reefs in setting and measuring progress toward realistic goals for coral-reef conservation and restoration, we examined reef degradation in this region from a geological perspective. The importance of ecosystem services provided by coral reefs—as breakwaters that dissipate wave energy and protect shorelines and as providers of habitat for innumerable species—cannot be overstated. However, the few coral species responsible for reef building in the western Atlantic during the last approximately 1.5 million years are not thriving in the 21st century. These species are highly sensitive to abrupt temperature extremes, prone to disease infection, and have low sexual reproductive potential. Their vulnerability and the low functional redundancy of branching corals have led to the low resilience of western Atlantic reef ecosystems. The decrease in live coral cover over the last 50 years highlights the need for study of relict (senescent) reefs, which, from the perspective of coastline protection and habitat structure, may be just as important to conserve as the living coral veneer. Research is needed to characterize the geological processes of bioerosion, reef cementation, and sediment transport as they relate to modern-day changes in reef elevation. For example, although parrotfish remove nuisance macroalgae, possibly promoting coral recruitment, they will not save Atlantic reefs from geological degradation. In fact, these fish are quickly nibbling away significant quantities of Holocene reef framework. The question of how different biota covering dead reefs affect framework resistance to biological and physical erosion needs to be addressed. Monitoring and managing reefs with respect to physical resilience, in addition to ecological resilience, could optimize the expenditure of

  12. CRED REA Belt Surveys of Coral Population and Disease Assessments at Kingman Reef, Pacific Remote Island Areas in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To support a long-term NOAA Coral Reef Conservation Program (CRCP) for sustainable management and conservation of coral reef ecosystems, from 14-19 April 2010, belt...

  13. CRED REA Belt Surveys of Coral Population and Disease Assessments at Maro Reef, NW Hawaiian Islands in 2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To support a long-term NOAA Coral Reef Conservation Program (CRCP) for sustainable management and conservation of coral reef ecosystems, from 12 September - 12...

  14. Comparison of machine learning algorithms for detecting coral reef

    Directory of Open Access Journals (Sweden)

    Eduardo Tusa

    2014-09-01

    Full Text Available (Received: 2014/07/31 - Accepted: 2014/09/23This work focuses on developing a fast coral reef detector, which is used for an autonomous underwater vehicle, AUV. A fast detection secures the AUV stabilization respect to an area of reef as fast as possible, and prevents devastating collisions. We use the algorithm of Purser et al. (2009 because of its precision. This detector has two parts: feature extraction that uses Gabor Wavelet filters, and feature classification that uses machine learning based on Neural Networks. Due to the extensive time of the Neural Networks, we exchange for a classification algorithm based on Decision Trees. We use a database of 621 images of coral reef in Belize (110 images for training and 511 images for testing. We implement the bank of Gabor Wavelets filters using C++ and the OpenCV library. We compare the accuracy and running time of 9 machine learning algorithms, whose result was the selection of the Decision Trees algorithm. Our coral detector performs 70ms of running time in comparison to 22s executed by the algorithm of Purser et al. (2009.

  15. Ophiuroidea (Echinodermata) from coral reefs in the Mexican Pacific

    Science.gov (United States)

    Granja–Fernández, Rebeca; Herrero-Pérezrul, María D.; López-Pérez, Ramón A.; Hernández, Luis; Rodríguez-Zaragoza, Fabián A.; Jones, Robert Wallace; Pineda-López, Rubén

    2014-01-01

    Abstract There are numerous and important coral reefs in the Mexican Pacific, but scarce studies of brittle stars conducted in these ecosystems. In this regard, this work provides the first annotated checklist of brittle stars associated with coral communities and reefs in the Mexican Pacific and an illustrated key to identify the species. We also provide taxonomic descriptions, spatial and bathymetric distributions and some important remarks of the species. We report a total of 14 species of brittle stars belonging to nine genera and seven families. Ophiocnida hispida in Jalisco, Ophiophragmus papillatus in Guerrero, and Ophiothrix (Ophiothrix) spiculata and Ophiactis simplex in Colima are new distribution records. The record of O. papillatus is remarkable because the species has not been reported since its description in 1940. The brittle stars collected in this study, represent 22.2% of the total species previously reported from the Mexican Pacific. Presently, anthropogenic activities on the coral reefs of the Mexican Pacific have increased, thus the biodiversity of brittle stars in these ecosystems may be threatened. PMID:24843284

  16. Spatial and Temporal Variability of Remotely Sensed Ocean Color Parameters in Coral Reef Regions

    Science.gov (United States)

    Otis, Daniel Brooks

    The variability of water-column absorption due to colored dissolved organic matter (CDOM) and phytoplankton in coral reef regions is the focus of this study. Hydrographic and CDOM absorption measurements made on the Bahamas Banks and in Exuma Sound during the spring of 1999 and 2000 showed that values of salinity and CDOM absorption at 440nm were higher on the banks (37.18 psu, 0.06 m. -1), compared to Exuma Sound (37.04 psu, 0.03 m. -1). Spatial patternsof CDOM absorption in Exuma Sound revealed that plumes of CDOM-rich water flow into Exuma Sound from the surrounding banks. To examine absorption variability in reef regions throughout the world, a thirteen-year time series of satellite-derived estimates of water-column absorption due to CDOM and phytoplankton were created from Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer (MODIS) data. Time series data extracted adjacent to coral reef regions showed that variability in absorption depends on oceanographic conditions such as circulation patterns and winds as well as proximity to sources of light-absorbing materials that enter the water column, such as from terrestrial runoff. Waters near reef regions are generally clear, exhibiting a lower "baseline" level of CDOM absorption of approximately 0.01 m. -1 at 443nm. The main differences between regions lie in the periodsduring the year when increased levels of absorption are observed, which can be triggered by inputs of terrestrially-derived material, as in the Great Barrier Reef lagoon, or wind-driven upwelling as in the Andaman Sea and eastern Pacific Ocean near Panama. The lowest CDOM absorption levels found were approximately 0.003 m. -1 at 443nm near the islands of Palau and Yap, which are removed fromsources of colored materials. The highest absorption levels near reefs were associated with wind-driven upwelling during the northeast monsoon on the Andaman coast of Thailand where values of CDOM absorption at 443nm

  17. Rapid Recent Warming of Coral Reefs in the Florida Keys.

    Science.gov (United States)

    Manzello, Derek P

    2015-01-01

    Coral reef decline in the Florida Keys has been well-publicized, controversial, and polarizing owing to debate over the causative agent being climate change versus overfishing. The recurrence of mass bleaching in 2014, the sixth event since 1987, prompted a reanalysis of temperature data. The summer and winter of 2014 were the warmest on record. The oldest known in-situ temperature record of any coral reef is from Hens and Chickens Reef (H&C) in the Florida Keys, which showed significant warming from 1975-2014. The average number of days ≥31.5 and 32(o)C per year increased 2670% and 2560%, respectively, from the mid-1990 s to present relative to the previous 20 years. In every year after 1992 and 1994, maximum daily average temperatures exceeded 30.5 and 31°C, respectively. From 1975-1994, temperatures were climate models and satellite-based sea temperatures. These data show that thermal stress is increasing and occurring on a near-annual basis on Florida Keys reefs due to ocean warming from climate change. PMID:26567884

  18. Vertical Sound Velocity Transition in the Coral Reef Core and its Significance of Indicating Facies

    Institute of Scientific and Technical Information of China (English)

    Li Ganxian; Lu Bo

    2002-01-01

    On the basis of the sound velocity measurements of the coral reef core from Nanyong No. 1 Well of Yongshu Reef in the Nansha Islands, the paper studies the relations between the vertical sound velocity transition features in the coral reef core and the corresponding stratigraphic depositional facies change as well as stratigraphic gap of erosion,analyses the cause of the sound velocity transition, expounds the concrete process of the sea level change resulting in the stratigraphic gap of erosion and facies change in the coral reef and explains the relations between the vertical sound velocity transition in the coral reef core and the corresponding stratigraphic paleoclimate and the sea level change. This study is of important practical value and theoretical significance to the island and reef engineering construction and the acoustic logging for oil exploration in the reef limestone area as well as the paleoceanographic study of the marginal sea in the western Pacific Ocean.

  19. Comparing Coral Reef Survey Methods. Unesco Reports in Marine Science No. 21 Report of a Regional Unesco/UNEP Workshop on Coral Reef Survey Management and Assessment Methods in Asia and the Pacific (Phuket, Thailand, December 13-17, 1982).

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Div. of Marine Sciences.

    This report includes nine papers prepared for a workshop on coral reef survey management and assessment methods in Asia and the Pacific. The papers are: "A Contrast in Methodologies between Surveying and Testing" (Charles Birkeland); "Coral Reef Survey Methods in the Andaman Sea" (Hansa Chansang); "A Review of Coral Reef Survey and Management…

  20. Coral Reef Genomics: Developing tools for functional genomics ofcoral symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Jodi; Brokstein, Peter; Manohar, Chitra; Coffroth, MaryAlice; Szmant, Alina; Medina, Monica

    2005-03-01

    Symbioses between cnidarians and dinoflagellates in the genus Symbiodinium are widespread in the marine environment. The importance of this symbiosis to reef-building corals and reef nutrient and carbon cycles is well documented, but little is known about the mechanisms by which the partners establish and regulate the symbiosis. Because the dinoflagellate symbionts live inside the cells of their host coral, the interactions between the partners occur on cellular and molecular levels, as each partner alters the expression of genes and proteins to facilitate the partnership. These interactions can examined using high-throughput techniques that allow thousands of genes to be examined simultaneously. We are developing the groundwork so that we can use DNA microarray profiling to identify genes involved in the Montastraea faveolata and Acropora palmata symbioses. Here we report results from the initial steps in this microarray initiative, that is, the construction of cDNA libraries from 4 of 16 target stages, sequencing of 3450 cDNA clones to generate Expressed Sequenced Tags (ESTs), and annotation of the ESTs to identify candidate genes to include in the microarrays. An understanding of how the coral-dinoflagellate symbiosis is regulated will have implications for atmospheric and ocean sciences, conservation biology, the study and diagnosis of coral bleaching and disease, and comparative studies of animal-protest interactions.

  1. Coral Reefs at the Northernmost Tip of Borneo: An Assessment of Scleractinian Species Richness Patterns and Benthic Reef Assemblages

    OpenAIRE

    Zarinah Waheed; Harald G J van Mil; Muhammad Ali Syed Hussein; Robecca Jumin; Bobita Golam Ahad; Hoeksema, Bert W.

    2015-01-01

    The coral reefs at the northernmost tip of Sabah, Borneo will be established under a marine protected area: the Tun Mustapha Park (TMP) by the end of 2015. This area is a passage where the Sulu Sea meets the South China Sea and it is situated at the border of the area of maximum marine biodiversity, the Coral Triangle. The TMP includes fringing and patch reefs established on a relatively shallow sea floor. Surveys were carried out to examine features of the coral reefs in terms of scleractini...

  2. Annual temperature anomaly trends correlate with coral reef trajectory across the Pacific

    Science.gov (United States)

    Riegl, B. M.; Wieters, E.; Bruckner, A.; Purkis, S.

    2013-05-01

    The future survival of coral reefs depends on the envelope of critical climatic conditions determining the severity of impacts on the ecosystem. While coral health is strongly determined by extreme heat events, that lead to bleaching and often death, chronic "heat loading" may also disadvantage corals by making them more susceptible to, for example, diseases. On the other hand, it has been shown that coral living in hotter areas have higher bleaching thresholds and may be affected by less mortality at extreme events. This level at which heat anomalies lead to coral mortality varies widely across oceans, from ~31 deg C across the Caribbean to ~32 deg C in the Great Barrier Reef to 37.5 deg C in the Persian/Arabian Gulf. Thus, there clearly exists local adaptation and the extremes required to kill reefs strongly vary among regions. This could be be interpreted as suggesting that as long as bleaching temperatures are not reached, increased overall heat content expressed by a positive annual thermal anomaly, might actually foster coral resilience. Is there evidence for or against such an argument? Bleaching events have been occurring worldwide with variable recurrence and variable subsequent recovery. Despite demonstrated adaptation to higher-than-usual mean summer temperatures, reefs in the Arabian Gulf and the Red Sea are on a declining trajectory. This coincides with consistent warming in the region. Mean annual anomalies of ocean temperature (since 1870) and atmospheric temperatures (since 1950) increase throughout the region. Since 1994 (Red Sea) and 1998 (southern Arabian Gulf) all mean annual anomalies have been positive and this period has coincided with repeated, severe bleaching events. In the Eastern Pacific (Galapagos and Easter Island), the trend of mean annual temperature anomalies has been declining and coral cover has been increasing. Thus, trends in coral cover and mean annual anomaly are negatively correlated in both regions. Despite strong impacts

  3. Management under uncertainty: guide-lines for incorporating connectivity into the protection of coral reefs

    Science.gov (United States)

    McCook, L. J.; Almany, G. R.; Berumen, M. L.; Day, J. C.; Green, A. L.; Jones, G. P.; Leis, J. M.; Planes, S.; Russ, G. R.; Sale, P. F.; Thorrold, S. R.

    2009-06-01

    The global decline in coral reefs demands urgent management strategies to protect resilience. Protecting ecological connectivity, within and among reefs, and between reefs and other ecosystems is critical to resilience. However, connectivity science is not yet able to clearly identify the specific measures for effective protection of connectivity. This article aims to provide a set of principles or practical guidelines that can be applied currently to protect connectivity. These ‘rules of thumb’ are based on current knowledge and expert opinion, and on the philosophy that, given the urgency, it is better to act with incomplete knowledge than to wait for detailed understanding that may come too late. The principles, many of which are not unique to connectivity, include: (1) allow margins of error in extent and nature of protection, as insurance against unforeseen or incompletely understood threats or critical processes; (2) spread risks among areas; (3) aim for networks of protected areas which are: (a) comprehensive and spread—protect all biotypes, habitats and processes, etc., to capture as many possible connections, known and unknown; (b) adequate—maximise extent of protection for each habitat type, and for the entire region; (c) representative—maximise likelihood of protecting the full range of processes and spatial requirements; (d) replicated—multiple examples of biotypes or processes enhances risk spreading; (4) protect entire biological units where possible (e.g. whole reefs), including buffers around core areas. Otherwise, choose bigger rather than smaller areas; (5) provide for connectivity at a wide range of dispersal distances (within and between patches), emphasising distances principles to coral reef management in the Bohol Sea (Philippines), the Great Barrier Reef (Australia) and Kimbe Bay (Papua New Guinea) are described.

  4. Microbial diversity associated with four functional groups of benthic reef algae and the reef-building coral Montastraea annularis.

    Science.gov (United States)

    Barott, Katie L; Rodriguez-Brito, Beltran; Janouškovec, Jan; Marhaver, Kristen L; Smith, Jennifer E; Keeling, Patrick; Rohwer, Forest L

    2011-05-01

    The coral reef benthos is primarily colonized by corals and algae, which are often in direct competition with one another for space. Numerous studies have shown that coral-associated Bacteria are different from the surrounding seawater and are at least partially species specific (i.e. the same bacterial species on the same coral species). Here we extend these microbial studies to four of the major ecological functional groups of algae found on coral reefs: upright and encrusting calcifying algae, fleshy algae, and turf algae, and compare the results to the communities found on the reef-building coral Montastraea annularis. It was found using 16S rDNA tag pyrosequencing that the different algal genera harbour characteristic bacterial communities, and these communities were generally more diverse than those found on corals. While the majority of coral-associated Bacteria were related to known heterotrophs, primarily consuming carbon-rich coral mucus, algal-associated communities harboured a high percentage of autotrophs. The majority of algal-associated autotrophic Bacteria were Cyanobacteria and may be important for nitrogen cycling on the algae. There was also a rich diversity of photosynthetic eukaryotes associated with the algae, including protists, diatoms, and other groups of microalgae. Together, these observations support the hypothesis that coral reefs are a vast landscape of distinctive microbial communities and extend the holobiont concept to benthic algae. PMID:21272183

  5. Tectonic subsidence provides insight into possible coral reef futures under rapid sea-level rise

    Science.gov (United States)

    Saunders, Megan I.; Albert, Simon; Roelfsema, Chris M.; Leon, Javier X.; Woodroffe, Colin D.; Phinn, Stuart R.; Mumby, Peter J.

    2016-03-01

    Sea-level rise will change environmental conditions on coral reef flats, which comprise extensive habitats in shallow tropical seas and support a wealth of ecosystem services. Rapid relative sea-level rise of 0.6 m over a relatively pristine coral reef in Solomon Islands, caused by a subduction earthquake in April 2007, generated a unique opportunity to examine in situ coral reef response to relative sea-level rise of the magnitude (but not the rate) anticipated by 2100. Extent of live coral was measured from satellite imagery in 2003, 2006, 2009 and 2012. Ecological data were obtained from microatolls and ecological surveys in May 2013. The reef was sampled at 12 locations where dense live hard coral remained absent, remained present or changed from absent to present following subsidence. Ecological data (substratum depth, live coral canopy depth, coral canopy height, substratum suitability, recruitment, diversity and Acropora presence) were measured at each location to identify factors associated with coral response to relative sea-level rise. Vertical and horizontal proliferation of coral occurred following subsidence. Lateral expansion of live coral, accomplished primarily by branching Acropora spp., resulted in lower diversity in regions which changed composition from pavement to dense live coral following subsidence. Of the ecological factors measured, biotic factors were more influential than abiotic factors; species identity was the most important factor in determining which regions of the reef responded to rapid sea-level rise. On relatively pristine reef flats under present climatic conditions, rapid relative sea-level rise generated an opportunity for hard coral to proliferate. However, the species assemblage of the existing reef was important in determining response to sea-level change, by providing previously bare substrate with a source of new coral colonies. Degraded reefs with altered species composition and slower coral growth rates may be less

  6. Persistence and change in community composition of reef corals through present, past, and future climates.

    Directory of Open Access Journals (Sweden)

    Peter J Edmunds

    Full Text Available The reduction in coral cover on many contemporary tropical reefs suggests a different set of coral community assemblages will dominate future reefs. To evaluate the capacity of reef corals to persist over various time scales, we examined coral community dynamics in contemporary, fossil, and simulated future coral reef ecosystems. Based on studies between 1987 and 2012 at two locations in the Caribbean, and between 1981 and 2013 at five locations in the Indo-Pacific, we show that many coral genera declined in abundance, some showed no change in abundance, and a few coral genera increased in abundance. Whether the abundance of a genus declined, increased, or was conserved, was independent of coral family. An analysis of fossil-reef communities in the Caribbean revealed changes in numerical dominance and relative abundances of coral genera, and demonstrated that neither dominance nor taxon was associated with persistence. As coral family was a poor predictor of performance on contemporary reefs, a trait-based, dynamic, multi-patch model was developed to explore the phenotypic basis of ecological performance in a warmer future. Sensitivity analyses revealed that upon exposure to thermal stress, thermal tolerance, growth rate, and longevity were the most important predictors of coral persistence. Together, our results underscore the high variation in the rates and direction of change in coral abundances on contemporary and fossil reefs. Given this variation, it remains possible that coral reefs will be populated by a subset of the present coral fauna in a future that is warmer than the recent past.

  7. The influence of fire-coral colony size and agonistic behaviour of territorial damselfish on associated coral reef fish communities.

    Science.gov (United States)

    Leal, Isabela Carolina Silva; de Araújo, Maria Elisabeth; da Cunha, Simone Rabelo; Pereira, Pedro Henrique Cipresso

    2015-07-01

    Branching hydrocorals from the genus Millepora play an important ecological role in South Atlantic reefs, where branching scleractinian corals are absent. Previous studies have shown a high proportion of reef fish species using branching fire-coral colonies as shelter, breeding, and feeding sites. However, the effects of Millepora spp. colony size and how the agonistic behaviour of a competitive damselfish affect the associated reef fish community are still unknown. The present study examined how fire-coral colony volume and the presence of a highly territorial and aggressive damselfish (Brazilian endemic Stegastes fuscus) affects the reef fish community associated with the fire-coral Millepora alcicornis. M. alcicornis colonies were surveyed from September 2012 to April 2013 at Tamandaré Reefs off Northeast Brazil. Our results show that the abundance and richness of coral associated fish was positively correlated with M. alcicornis coral colony volume. Additionally, behaviour of S. fuscus, the most abundant reef fish species found associated with fire-coral colonies (almost 57% of the fish community), was also influenced by fire-coral colony volume. There was a clear trend of increased agonistic behaviour and feeding on coral polyps as colony volume increased. This trend was reversed for the non-occupational swimming category, which decreased as M. alcicornis colony volume increased. Behavioural ontogenetic changes were also detected for S. fuscus individuals. Juveniles mainly showed two distinct behaviours: sheltered on coral branches and feeding on coral polyps. In contrast, adults presented greater equitability among the behavioural categories, mostly non-occupational swimming around coral colonies and agonistic behaviour. Lastly, S. fuscus individuals actively defended fire-coral colonies from intruders. A large number of agonistic interactions occurred against potential food competitors, which were mainly roving herbivores, omnivores, and sessile

  8. Status of Coral Reefs in the Western Indian Ocean and Evolving Coral Reef Programmes.

    OpenAIRE

    Salm, Rod; Muthiga, Nyawira; Muhando, Chris

    1998-01-01

    The region has all reef types from atolls to fringing reefs with many endemic species shared within the Western Indian Ocean (WIO), which suggests that the reefs are linked by currents to make this a discrete biogeographic region. This also means there is a need for regional collaboration among the ten WIO states to manage these reefs. Reef management is not well developed in the WIO, and is focused at the site rather than at national or regional levels. Poorly regulated fisheries and coastal...

  9. Responses of Cryptofaunal Species Richness and Trophic Potential to Coral Reef Habitat Degradation

    Directory of Open Access Journals (Sweden)

    Derek P. Manzello

    2012-02-01

    Full Text Available Coral reefs are declining worldwide as a result of many anthropogenic disturbances. This trend is alarming because coral reefs are hotspots of marine biodiversity and considered the ‘rainforests of the sea. As in the rainforest, much of the diversity on a coral reef is cryptic, remaining hidden among the cracks and crevices of structural taxa. Although the cryptofauna make up the majority of a reef’s metazoan biodiversity, we know little about their basic ecology or how these communities respond to reef degradation. Emerging research shows that the species richness of the motile cryptofauna is higher among dead (framework vs. live coral substrates and, surprisingly, increases within successively more eroded reef framework structures, ultimately reaching a maximum in dead coral rubble. Consequently, the paradigm that abundant live coral is the apex of reef diversity needs to be clarified. This provides guarded optimism amidst alarming reports of declines in live coral cover and the impending doom of coral reefs, as motile cryptic biodiversity should persist independent of live coral cover. Granted, the maintenance of this high species richness is contingent on the presence of reef rubble, which will eventually be lost due to physical, chemical, and biological erosion if not replenished by live coral calcification and mortality. The trophic potential of a reef, as inferred from the abundance of cryptic organisms, is highest on live coral. Among dead framework substrates, however, the density of cryptofauna reaches a peak at intermediate levels of degradation. In summary, the response of the motile cryptofauna, and thus a large fraction of the reef’s biodiversity, to reef degradation is more complex and nuanced than currently thought; such that species richness may be less sensitive than overall trophic function.

  10. Long-term monitoring of reef corals at the Flower Garden Banks (northwest Gulf of Mexico): Reef coral population changes and historical incorporation of barium in Montastrea annularis

    Energy Technology Data Exchange (ETDEWEB)

    Deslarzes, K.J.P.

    1992-01-01

    Reef coral populations were monitored from 1988 to 1991 at the Flower Garden Banks located in the northwestern Gulf of Mexico. The status of reef coral populations, and natural or man-made factors potentially affecting their well-being were determined. Man-made chronic disturbances are degrading coral reef resources on a global scale. Yet, the Flower Garden coral reefs seem to have been sheltered from the effects of regional stresses generated by population growth and increased industrial activity. Since 1974, reef coral population levels have remained unchanged in the Montastrea-Diploria Zones at the Flower Garden Banks. Live coral cover ranges between 46 and 46.5%. Montastrea annularis and Diploria strigosa comprise 80% of the coral cover on either bank. The remainder of the cover is mostly shared by eight other taxa. Coral taxa appear to be more homogeneously distributed on the West Bank. The relatively greater number of Agaricia spp., Madracis decastis, and P. astreoides colonies on the East Bank may be the source of a decreased evenness. The health of reef corals was assessed using repetitive and non-repetitive photographic methods, and accretionary growth measurements of M. annularis. Reef corals have undergone small scale changes at the Flower Gardens probably reflecting natural disturbance, predation, disease, and inter-specific competition. White mat disease (ridge disease) is shown to generate more tissue loss than any of the three bleaching events that took place at the Flower Gardens (1989, 1990, and 1991). Advance to retreat linear ratios of encrusting growth revealed a net tissue gain on the East Bank and a net tissue loss on the West Bank. Growth rates of M. annularis were highly variable. The annual barium content from 1910 in 1989 in a M. annularis colony from the West Flower Garden did not reveal trends associated with the extensive oil and gas exploration in the northern Gulf of Mexico.

  11. Crustal activities recorded in coral reefs in the northwestern South China Sea

    Institute of Scientific and Technical Information of China (English)

    ZHAN Wenhuan; YAO Yantao; ZHANG Zhiqiang; SUN Zongxun; ZHAN Meizhen; SUN Longtao; LIU Zaifeng

    2006-01-01

    Coral reefs in the northwest of South China Sea have recorded the information from not only the environmental variation but also the crustal activities there during their development. The main crustal activities correlated with the coral reef development include fault, seismic, and volcano activities,etc. The high-resolution spark seismic profiles in the northwestern South China Sea show that the fault activities in the coral reef region have been clearly recorded, and appear as neonatal faults incising reefs. Earthquakes in the coral reef region are rather intense, especially the two occurring on December,31, 1994, and January, 10, 1995, around the southwest of Leizhou Peninsula, with the magnitude of 6.1and 6.2, respectively. They have great influence on the growth of the local coral reefs. Quaternary volcanos are active in the northwestern South China Sea, especially around the southwest of Leizhou Peninsula, and they have obvious control of the coral reef development. Some submarine volcanoes form the substrates of coral reef, while a few emerge above the sea surface and form coral islands.

  12. Developing a Biological Condition Gradient for the Protection of Puerto Rico's Coral Reefs

    Science.gov (United States)

    We introduce the application of the Biological Condition Gradient (BCG) to coral reefs: a conceptual model that describes how biological attributes of coral reef ecosystems might change along a gradient of increasing anthropogenic stress. Under authority of the Clean Water Act, t...

  13. 77 FR 16211 - Availability of Seats for the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory...

    Science.gov (United States)

    2012-03-20

    ... Coral Reef Ecosystem Reserve Advisory Council AGENCY: Office of National Marine Sanctuaries (ONMS... . SUPPLEMENTARY INFORMATION: The NWHI Coral Reef Ecosystem Reserve is a marine protected area designed to conserve... Ecosystem Reserve Advisory Council, pursuant to section 315 of the National Marine Sanctuaries Act,...

  14. Hydrogeology and hydrodynamics of coral reef pore waters

    Energy Technology Data Exchange (ETDEWEB)

    Buddemeier, R.W.; Oberdorfer, J.A.

    1988-06-29

    A wide variety of forces can produce head gradients that drive the flow and advective mixing of internal coral reef pore waters. Oscillatory gradients that produce mixing result from wave and tide action. Sustained gradients result from wave and tide-induced setup and ponding, from currents impinging on the reef structure, from groundwater heads, and from density differenced (temperature or salinity gradients). These gradients and the permeabilities and porosities of reef sediments are such that most macropore environments are dominated by advection rather than diffusion. The various driving forces must be analyzed to determine the individual and combined magnitudes of their effects on a specific reef pore-water system. Pore-water movement controls sediment diagenesis, the exchange of nutrients between sediments and benthos, and coastal/island groundwater resources. Because of the complexity of forcing functions, their interactions with specific local reef environments, experimental studies require careful incorporation of these considerations into their design and interpretation. 8 refs., 3 figs., 1 tab.

  15. Quantifying and Valuing Potential Climate Change Impacts on Coral Reefs in the United States

    Science.gov (United States)

    Wobus, C. W.; Lane, D.; Buddemeier, R. W.; Ready, R. C.; Shouse, K. C.; Martinich, J.

    2012-12-01

    Global climate change presents a two-pronged threat to coral reef ecosystems: increasing sea surface temperatures will increase the likelihood of episodic bleaching events, while increasing ocean carbon dioxide concentrations will change the carbonate chemistry that drives coral growth. Because coral reefs have important societal as well as ecological benefits, climate change mitigation policies that ameliorate these impacts may create substantial economic value. We present a model that evaluates both the ecological and the economic impacts of climate change on coral reefs in the United States. We use a coral reef mortality and bleaching model to project future coral reef declines under a range of climate change policy scenarios for south Florida, Puerto Rico and Hawaii. Using a benefits transfer approach, the outputs from the physical model are then used to quantify the economic impacts of these coral reef declines for each of these regions. We find that differing climate change trajectories create substantial changes in projected coral cover and value for Hawaii, but that the ecological and economic benefits of more stringent emissions scenarios are less clear for Florida and Puerto Rico. Overall, our results indicate that the effectiveness of climate change mitigation policies may be region-specific, but that these policies could result in a net increase of nearly $10 billion in economic value from coral reef-related recreational activities alone, over the 21st century.

  16. Global and local threats to coral reef functioning and existence: review and predictions

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, C.R. [Australian Institute of Marine Sciences, Townsville, Qld. (Australia)

    1999-07-01

    Factors causing global degradation of coral reefs are examined briefly as a basis for predicting the likely consequences of increases in these factors. The earlier consensus was that widespread but localized damage from natural factors such as storms, and direct anthropogenic effects such as increased sedimentation, pollution and exploitation, posed the largest immediate threat to coral reefs. Now truly global factors associated with accelerating Global Climate Change are either damaging coral reefs or have the potential to inflict greater damage in the immediate future e.g. increases in coral bleaching and mortality, and reduction in coral calcification due to changes in sea-water chemistry with increasing carbon dioxide concentrations. Rises in sea level will probably disrupt human communities and their cultures by making coral cays uninhabitable, whereas coral reefs will sustain minimal damage from the rise in sea level. The short-term (decades) prognosis is that major reductions are almost certain in the extent and biodiversity of coral reefs, and severe disruptions to cultures and economies dependent on reef resources will occur. The long-term (centuries to millennia) prognosis is more encouraging because coral reefs have remarkable resilience to severe disruption and will probably show this resilience in the future when climate changes either stabilize or reverse.

  17. Spatial and tidal variation in food supply to shallow cold-water coral reefs of the Mingulay Reef complex (Outer Hebrides, Scotland)

    NARCIS (Netherlands)

    Duineveld, G.C.A.; Jeffreys, R.M.; Lavaleye, M.S.S.; Davies, A.J.; Bergman, M.J.N.; Watmough, T.; Witbaard, R.

    2012-01-01

    The finding of a previously undescribed cold-water coral reef (Banana Reef) in the Scottish Mingulay reef complex, with denser coverage of living Lophelia pertusa than the principal Mingulay 1 Reef, was the incentive for a comparative study of the food supply to the 2 reefs. Suspended particulate ma

  18. Assessment of the Water Quality and Ecosystem Health of the Great Barrier Reef (Australia): Conceptual Models

    Science.gov (United States)

    Haynes, David; Brodie, Jon; Waterhouse, Jane; Bainbridge, Zoe; Bass, Deb; Hart, Barry

    2007-12-01

    Run-off containing increased concentrations of sediment, nutrients, and pesticides from land-based anthropogenic activities is a significant influence on water quality and the ecologic conditions of nearshore areas of the Great Barrier Reef World Heritage Area, Australia. The potential and actual impacts of increased pollutant concentrations range from bioaccumulation of contaminants and decreased photosynthetic capacity to major shifts in community structure and health of mangrove, coral reef, and seagrass ecosystems. A detailed conceptual model underpins and illustrates the links between the main anthropogenic pressures or threats (dry-land cattle grazing and intensive sugar cane cropping) and the production of key contaminants or stressors of Great Barrier Reef water quality. The conceptual model also includes longer-term threats to Great Barrier Reef water quality and ecosystem health, such as global climate change, that will potentially confound direct model interrelationships. The model recognises that system-specific attributes, such as monsoonal wind direction, rainfall intensity, and flood plume residence times, will act as system filters to modify the effects of any water-quality system stressor. The model also summarises key ecosystem responses in ecosystem health that can be monitored through indicators at catchment, riverine, and marine scales. Selected indicators include riverine and marine water quality, inshore coral reef and seagrass status, and biota pollutant burdens. These indicators have been adopted as components of a long-term monitoring program to enable assessment of the effectiveness of change in catchment-management practices in improving Great Barrier Reef (and adjacent catchment) water quality under the Queensland and Australian Governments’ Reef Water Quality Protection Plan.

  19. Bright spots among the world’s coral reefs

    Science.gov (United States)

    Cinner, Joshua E.; Huchery, Cindy; MacNeil, M. Aaron; Graham, Nicholas A. J.; McClanahan, Tim R.; Maina, Joseph; Maire, Eva; Kittinger, John N.; Hicks, Christina C.; Mora, Camilo; Allison, Edward H.; D’Agata, Stephanie; Hoey, Andrew; Feary, David A.; Crowder, Larry; Williams, Ivor D.; Kulbicki, Michel; Vigliola, Laurent; Wantiez, Laurent; Edgar, Graham; Stuart-Smith, Rick D.; Sandin, Stuart A.; Green, Alison L.; Hardt, Marah J.; Beger, Maria; Friedlander, Alan; Campbell, Stuart J.; Holmes, Katherine E.; Wilson, Shaun K.; Brokovich, Eran; Brooks, Andrew J.; Cruz-Motta, Juan J.; Booth, David J.; Chabanet, Pascale; Gough, Charlie; Tupper, Mark; Ferse, Sebastian C. A.; Sumaila, U. Rashid; Mouillot, David

    2016-07-01

    Ongoing declines in the structure and function of the world’s coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them. A presently unexplored approach that draws on theory and practice in human health and rural development is to systematically identify and learn from the ‘outliers’—places where ecosystems are substantially better (‘bright spots’) or worse (‘dark spots’) than expected, given the environmental conditions and socioeconomic drivers they are exposed to. Here we compile data from more than 2,500 reefs worldwide and develop a Bayesian hierarchical model to generate expectations of how standing stocks of reef fish biomass are related to 18 socioeconomic drivers and environmental conditions. We identify 15 bright spots and 35 dark spots among our global survey of coral reefs, defined as sites that have biomass levels more than two standard deviations from expectations. Importantly, bright spots are not simply comprised of remote areas with low fishing pressure; they include localities where human populations and use of ecosystem resources is high, potentially providing insights into how communities have successfully confronted strong drivers of change. Conversely, dark spots are not necessarily the sites with the lowest absolute biomass and even include some remote, uninhabited locations often considered near pristine. We surveyed local experts about social, institutional, and environmental conditions at these sites to reveal that bright spots are characterized by strong sociocultural institutions such as customary taboos and marine tenure, high levels of local engagement in management, high dependence on marine resources, and beneficial environmental conditions such as deep-water refuges. Alternatively, dark spots are characterized by intensive capture and storage technology and a recent history of environmental shocks. Our results suggest that investments in strengthening fisheries

  20. Bright spots among the world’s coral reefs.

    Science.gov (United States)

    Cinner, Joshua E; Huchery, Cindy; MacNeil, M Aaron; Graham, Nicholas A J; McClanahan, Tim R; Maina, Joseph; Maire, Eva; Kittinger, John N; Hicks, Christina C; Mora, Camilo; Allison, Edward H; D'Agata, Stephanie; Hoey, Andrew; Feary, David A; Crowder, Larry; Williams, Ivor D; Kulbicki, Michel; Vigliola, Laurent; Wantiez, Laurent; Edgar, Graham; Stuart-Smith, Rick D; Sandin, Stuart A; Green, Alison L; Hardt, Marah J; Beger, Maria; Friedlander, Alan; Campbell, Stuart J; Holmes, Katherine E; Wilson, Shaun K; Brokovich, Eran; Brooks, Andrew J; Cruz-Motta, Juan J; Booth, David J; Chabanet, Pascale; Gough, Charlie; Tupper, Mark; Ferse, Sebastian C A; Sumaila, U Rashid; Mouillot, David

    2016-07-21

    Ongoing declines in the structure and function of the world’s coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them3. A presently unexplored approach that draws on theory and practice in human health and rural development is to systematically identify and learn from the ‘outliers’—places where ecosystems are substantially better (‘bright spots’) or worse (‘dark spots’) than expected, given the environmental conditions and socioeconomic drivers they are exposed to. Here we compile data from more than 2,500 reefs worldwide and develop a Bayesian hierarchical model to generate expectations of how standing stocks of reef fish biomass are related to 18 socioeconomic drivers and environmental conditions. We identify 15 bright spots and 35 dark spots among our global survey of coral reefs, defined as sites that have biomass levels more than two standard deviations from expectations. Importantly, bright spots are not simply comprised of remote areas with low fishing pressure; they include localities where human populations and use of ecosystem resources is high, potentially providing insights into how communities have successfully confronted strong drivers of change. Conversely, dark spots are not necessarily the sites with the lowest absolute biomass and even include some remote, uninhabited locations often considered near pristine6. We surveyed local experts about social, institutional, and environmental conditions at these sites to reveal that bright spots are characterized by strong sociocultural institutions such as customary taboos and marine tenure, high levels of local engagement in management, high dependence on marine resources, and beneficial environmental conditions such as deep-water refuges. Alternatively, dark spots are characterized by intensive capture and storage technology and a recent history of environmental shocks. Our results suggest that investments in strengthening fisheries

  1. Sustaining Coral Reef Ecosystems and their Fisheries in the Kiunga Marine National Reserve, Lamu, Kenya.

    OpenAIRE

    Church, J.; Obura, D. O.

    2006-01-01

    Coral reefs in the Kiunga Marine National Reserve (KMNR) (40o 07’ E, 2o 00’ S) are located in a transition ecotone between the warmer East African coral reef bioregion to the south, and colder waters of the Somali Current to the north. The reefs have been monitored annually from 1998 to the present, documenting a range of ecosystem changes from large and small scale threats. Reefs in the area suffered ˜60% loss of coral cover due to mass bleaching in the 1998 El Niño event, and 25-40% loss of...

  2. Population Genetics of an Ecosystem-Defining Reef Coral Pocillopora damicornis in the Tropical Eastern Pacific

    OpenAIRE

    Combosch, David J.; Vollmer, Steven V.

    2011-01-01

    BACKGROUND: Coral reefs in the Tropical Eastern Pacific (TEP) are amongst the most peripheral and geographically isolated in the world. This isolation has shaped the biology of TEP organisms and lead to the formation of numerous endemic species. For example, the coral Pocillopora damicornis is a minor reef-builder elsewhere in the Indo-West Pacific, but is the dominant reef-building coral in the TEP, where it forms large, mono-specific stands, covering many hectares of reef. Moreover, TEP P. ...

  3. Critical research needs for identifying future changes in Gulf coral reef ecosystems

    KAUST Repository

    Feary, David A.

    2013-07-01

    Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter \\'Gulf\\') coral reefs. Thirty-one participants submitted 71 research questions that were peer-assessed in terms of scientific importance (i.e., filled a knowledge gap and was a research priority) and efficiency in resource use (i.e., was highly feasible and ecologically broad). Ten research questions, in six major research areas, were highly important for both understanding Gulf coral reef ecosystems and also an efficient use of limited research resources. These questions mirrored global evaluations of the importance of understanding and evaluating biodiversity, determining the potential impacts of climate change, the role of anthropogenic impacts in structuring coral reef communities, and economically evaluating coral reef communities. These questions provide guidance for future research on coral reef ecosystems within the Gulf, and enhance the potential for assessment and management of future changes in this globally significant region. © 2013 Elsevier Ltd.

  4. National Coral Reef Monitoring Program: Assessment of coral reef communities in U.S. Virgin Islands (USVI) using the Line Point-Intercept (LPI) method

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Line Point-Intercept (LPI) method is one of two benthic surveys conducted in the U.S. Virgin Islands (USVI) as part of the National Coral Reef Monitoring...

  5. National Coral Reef Monitoring Program - Assessment of coral reef fish communities in Puerto Rico from 2014-05-19 to 2014-12-03 (NCEI Accession 0131260)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Coral Reef Monitoring Plan (NCRMP) is a framework for conducting sustained observations of biological, climate, and socioeconomic indicators at 10...

  6. National Coral Reef Monitoring Program: Assessment of coral reef benthic communities in Puerto Rico from 2014-05-19 to 2014-12-03 (NCEI Accession 0151729)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic data collection for the National Coral Reef Ecosystem Monitoring Program (NCRMP) consists of two survey types: the Line Point-Intercept (LPI) method and the...

  7. National Coral Reef Monitoring Program: Assessment of coral reef communities in Puerto Rico using the Line Point-Intercept (LPI) method

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Line Point-Intercept (LPI) method is one of two benthic surveys conducted in Puerto Rico as part of the National Coral Reef Monitoring Program (NCRMP). The LPI...

  8. Coral reef digital still images and benthic species of the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP) on Maui in 2014 (NCEI Accession 0147682)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of digitial still images along coral reef transect lines, and photoquads on some transect lines, as well as quantitative benthic data for...

  9. National Coral Reef Monitoring Program: Assessment of coral reef communities in U.S. Virgin Islands (USVI) using the Belt Transect fish census method

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Belt Transect method is used to conduct fish surveys in the U.S. Virgin Islands (USVI) as part of the National Coral Reef Monitoring Program (NCRMP). The Belt...

  10. Climate change, coral bleaching and the future of the world's coral reefs

    Energy Technology Data Exchange (ETDEWEB)

    Hoegh-Guldberg, O. [University of Sydney, Sydney, NSW (Australia). School of Biological Sciences

    1999-07-01

    Sea temperatures in many tropical regions have increased by almost 1{degree}C over the past 100 years, and are currently increasing at about 1-2{degree}C per century. Mass coral bleaching has occurred in association with episodes of elevated sea temperatures over the past 20 years and involves the loss of the zooxanthellae following chronic photoinhibition. Mass bleaching has resulted in significant losses of live coral in many parts of the world. This paper considers the biochemical, physiological and ecological perspectives of coral bleaching. It also uses the outputs of four runs from three models of global climate change which simulate changes in sea temperature and hence how the frequency and intensity of bleaching events will change over the next 100 years. The results suggest that the thermal tolerances of reef-building corals are likely to be exceeded every year within the next few decades. Events as severe as the 1998 event, the worst on record, are likely to become commonplace within 20 years. Most information suggests that the capacity for acclimation by corals has already been exceeded, and that adaptation will be too slow to avert a decline in the quality of the world's reefs.

  11. The Effect of the Great Barrier Reef on the Propagation of the 2007 Solomon Islands Tsunami Recorded in Northeastern Australia

    Science.gov (United States)

    Baba, Toshitaka; Mleczko, Richard; Burbidge, David; Cummins, Phil R.; Thio, Hong Kie

    2008-12-01

    The effect of offshore coral reefs on the impact from a tsunami remains controversial. For example, field surveys after the 2004 Indian Ocean tsunami indicate that the energy of the tsunami was reduced by natural coral reef barriers in Sri Lanka, but there was no indication that coral reefs off Banda Aceh, Indonesia had any effect on the tsunami. In this paper, we investigate whether the Great Barrier Reef (GBR) offshore Queensland, Australia, may have weakened the tsunami impact from the 2007 Solomon Islands earthquake. The fault slip distribution of the 2007 Solomon Islands earthquake was firstly obtained by teleseismic inversion. The tsunami was then propagated to shallow water just offshore the coast by solving the linear shallow water equations using a staggered grid finite-difference method. We used a relatively high resolution (approximately 250 m) bathymetric grid for the region just off the coast containing the reef. The tsunami waveforms recorded at tide gauge stations along the Australian coast were then compared to the results from the tsunami simulation when using both the realistic 250 m resolution bathymetry and with two grids having fictitious bathymetry: One in which the the GBR has been replaced by a smooth interpolation from depths outside the GBR to the coast (the “No GBR” grid), and one in which the GBR has been replaced by a flat plane at a depth equal to the mean water depth of the GBR (the “Average GBR” grid). From the comparison between the synthetic waveforms both with and without the Great Barrier Reef, we found that the Great Barrier Reef significantly weakened the tsunami impact. According to our model, the coral reefs delayed the tsunami arrival time by 5-10 minutes, decreased the amplitude of the first tsunami pulse to half or less, and lengthened the period of the tsunami.

  12. Trampling on coral reefs: tourism effects on harpacticoid copepods

    Science.gov (United States)

    Sarmento, V. C.; Santos, P. J. P.

    2012-03-01

    Human trampling is a common type of disturbance associated with outdoor recreational activities in coastal ecosystems. In this study, the effect of trampling on the meiofaunal harpacticoid copepod assemblage inhabiting turfs on a coral reef was investigated. In Porto de Galinhas, northeastern Brazil, reef formations near the beach are one of the main touristic destinations in the country. To assess trampling impact, two areas were compared: a protected area and an area subject to intensive tourism. Densities of total Harpacticoida and of the most abundant harpacticoid species showed strong reductions in the trampled area. An analysis of covariance revealed that the loss of phytal habitat was not the main source of density reductions, showing that trampling affected the animals directly. In addition, multivariate analysis demonstrated differences in the structure of harpacticoid assemblages between areas. Of the 43 species identified, 12 were detected by the Indicator Species Analyses as being indicators of the protected or trampled areas. Moreover, species richness was reduced in the area open to tourism. At least 25 harpacticoids are new species for science, of these, 20 were more abundant or occurred only in the protected area, while five were more abundant or occurred only in the trampled area; thus, our results highlight the possibility of local extinction of still-unknown species as one of the potential consequences of trampling on coral reefs.

  13. Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals

    OpenAIRE

    Tse-Lynn Loh; Steven E. McMurray; Henkel, Timothy P.; Jan Vicente; Joseph R Pawlik

    2015-01-01

    Consumer-mediated indirect effects at the community level are difficult to demonstrate empirically. Here, we show an explicit indirect effect of overfishing on competition between sponges and reef-building corals from surveys of 69 sites across the Caribbean. Leveraging the large-scale, long-term removal of sponge predators, we selected overfished sites where intensive methods, primarily fish-trapping, have been employed for decades or more, and compared them to sites in remote or marine prot...

  14. Dietary shift in juvenile coral trout ( Plectropomus maculatus) following coral reef degradation from a flood plume disturbance

    Science.gov (United States)

    Wen, Colin K. C.; Bonin, Mary C.; Harrison, Hugo B.; Williamson, David H.; Jones, Geoffrey P.

    2016-06-01

    Acute environmental disturbances impact on habitat quality and resource availability, which can reverberate through trophic levels and become apparent in species' dietary composition. In this study, we observed a distinct dietary shift of newly settled and juvenile coral trout ( Plectropomus maculatus) following severe coral reef habitat degradation after a river flood plume affected the Keppel Islands, Australia. Hard coral cover declined by ~28 % in the 2 yr following the 2010-2011 floods, as did the abundance of young coral trout. Gut contents analysis revealed that diets had shifted from largely crustacean-based to non-preferred prey fishes following the disturbances. These results suggest that newly settled and juvenile coral trout modify their diet and foraging strategy in response to coral habitat degradation. This bottom-up effect of habitat degradation on the diet of a top coral reef predator may incur a metabolic cost, with subsequent effects on growth and survival.

  15. The Role of Observation Systems in Coral Reef Monitoring and Management

    Science.gov (United States)

    Bainbridge, S.; Steinberg, C.; Rigby, P.

    2009-05-01

    The Great Barrier Reef (GBR) located along north eastern Australia consists of some 3,500 individual reefs along 2,500km of coast. At over 315,000 square kilometres in area it represents a large dynamic system, is complex at all scales, sparsely monitored and relatively poorly understood. Managing such a complex system, including the impact of threats such as Climate Change and terrestrial run-off, requires a detailed understanding of the forces that drive the system and the resulting observed biological responses such as productivity, coral bleaching and coral disease. The Great Barrier Reef Ocean Observing System (GBROOS), a geographic node of the Australian Integrated Marine Observing System (IMOS), has deployed a range of observing infrastructure at a number of sites along the GBR. The project looks to measure and monitor the impact of oceanic water from the Coral Sea on the continental shelf reef systems an in particular the role of upwelling and intrusions. In the southern region there is a concentration of observing infrastructure around Heron and One Tree Islands including deep water moorings, ocean surface radar, satellite remote sensing (SST and Ocean Colour), on- reef meteorological stations and wireless sensor networks. This area therefore provides an opportunity to gain an understanding of how the oceanic waters impact and force shallower reef systems and in particular how the thermal environment within the reef lagoons is influenced by oceanic and other processes. The data from all of these systems will be integrated to form a picture of the thermal events occurring in this region during the 2008-09 summer period. Initial analysis of the real-time sensor network data shows the lagoons of Heron and One Tree Islands heating slowly over a number of weeks followed often by sharp cooling periods where the lagoon temperature can drop five degrees Celsius in a day or two. The presentation will look to link the within lagoon data with the deep water data

  16. Sustaining Ecosystem Services in the Global Coral Reef Crisis

    Science.gov (United States)

    Aronson, Richard B.; Precht, William F.

    2009-07-01

    Objective science is critical to understanding the relative impacts of the many putative causal agents in the global coral reef crisis. This paper provides an evidence-based scenario of causality leading to the current state of reef degradation. Contrary to revisionist narratives that emphasize the local-scale effects of fishing and nutrient loading, coral populations were and are degrading primarily due to regional-to global-scale factors. Most important among these large-scale factors are disease outbreaks and coral bleaching, both of which are related to climate change. Because policy recommendations and management strategies will differ depending on which cause(s) are perceived to exert the greatest influence, scientists must be explicit about when they are acting as advocates and when they are objectively conveying scientific results. Legitimate scientific debate is healthy and in no way diminishes the goal of creating cogent policy. Forced ideological unification, in contrast, risks obfuscation, undermining the scientific process. Science must move forward unfettered by political expediency; however, the situation is dire enough to warrant immediate action on local, regional, and global levels, based on the best scientific information at hand, in parallel with continuing research.

  17. Cold induces acute stress but heat is ultimately more deleterious for the reef-building coral Acropora yongei

    OpenAIRE

    Roth, Melissa S.; Ralf Goericke; Deheyn, Dimitri D.

    2012-01-01

    Climate change driven increases in intensity and frequency of both hot and cold extreme events contribute to coral reef decline by causing widespread coral bleaching and mortality. Here, we show that hot and cold temperature changes cause distinct physiological responses on different time scales in reef-building corals. We exposed the branching coral Acropora yongei in individual aquaria to a ± 5°C temperature change. Compared to heat-treated corals, cold-treated corals initially show greater...

  18. Small change, big difference: Sea surface temperature distributions for tropical coral reef ecosystems, 1950-2011

    Science.gov (United States)

    Lough, J. M.

    2012-09-01

    Changes in tropical sea surface temperature (SST) are examined over the period 1950-2011 during which global average temperature warmed by 0.4°C. Average tropical SST is warming about 70% of the global average rate. Spatially, significant warming between the two time periods, 1950-1980 and 1981-2011, has occurred across 65% of the tropical oceans. Coral reef ecosystems occupy 10% of the tropical oceans, typically in regions of warmer (+1.8°C) and less variable SST (80% of months within 3.3°C range) compared to non-reef areas (80% of months within 7.0°C range). SST is a primary controlling factor of coral reef distribution and coral reef organisms have already shown their sensitivity to the relatively small amount of warming observed so far through, for example, more frequent coral bleaching events and outbreaks of coral disease. Experimental evidence is also emerging of possible thermal thresholds in the range 30°C-32°C for some physiological processes of coral reef organisms. Relatively small changes in SST have already resulted in quite large differences in SST distribution with a maximum ‘hot spot’ of change in the near-equatorial Indo-Pacific which encompasses both the Indo-Pacific warm pools and the center of coral reef biodiversity. Identification of this hot spot of SST change is not new but this study highlights its significance with respect to tropical coral reef ecosystems. Given the modest amount of warming to date, changes in SST distribution are of particular concern for coral reefs given additional local anthropogenic stresses on many reefs and ongoing ocean acidification likely to increasingly compromise coral reef processes.

  19. Diversity of trypanorhynch metacestodes in teleost fishes from coral reefs off eastern Australia and New Caledonia

    Directory of Open Access Journals (Sweden)

    Beveridge Ian

    2014-01-01

    Full Text Available Trypanorhynch metacestodes were examined from teleosts from coral reefs in eastern Australia and from New Caledonia. From over 12,000 fishes examined, 33 named species of trypanorhynchs were recovered as well as three species of tentacularioids which are described but not named. Host-parasite and parasite-host lists are provided, including more than 100 new host records. Lacistorhynchoid and tentacularioid taxa predominated with fewer otobothrioid and gymnorhynchoids. Five species, Callitetrarhynchus gracilis, Floriceps minacanthus, Pseudotobothrium dipsacum, Pseudolacistorhynchus heroniensis and Ps. shipleyi, were particularly common and exhibited low host specificity. Limited data suggested a higher diversity of larval trypanorhynchs in larger piscivorous fish families. Several fish families surveyed extensively (Blenniidae, Chaetodontidae, Gobiidae, Kyphosidae and Scaridae yielded no trypanorhynch larvae. The overall similarity between the fauna of the Great Barrier Reef and New Caledonia was 45%. Where available, information on the adult stages in elasmobranchs has been included.

  20. Economic Valuation of Coral Reefs at Mombasa Marine National Park and Reserve, Kenya.

    OpenAIRE

    Ransom, Kevin Paul

    2008-01-01

    Kenya's coral reefs, and the livelihoods and communities they support, face numerous threats including global climate change and a growing coastal human population. A contingent valuation study was conducted with Kenyan citizen and foreign tourists to evaluate the conservation benefits of coral reefs at Mombasa Marine National Park and Reserve (MMNPR), and assess the implications for local reef management. Citizen and foreign visitors to MMNPR were willing to pay an extra US$2.23 and US$7.94 ...

  1. Recent Advances in Understanding the Effects of Climate Change on Coral Reefs

    OpenAIRE

    Hoey, Andrew S.; Emily Howells; Johansen, Jacob L.; Hobbs, Jean-Paul A.; Vanessa Messmer; Dominique M. McCowan; Wilson, Shaun K.; Pratchett, Morgan S.

    2016-01-01

    Climate change is one of the greatest threats to the persistence of coral reefs. Sustained and ongoing increases in ocean temperatures and acidification are altering the structure and function of reefs globally. Here, we summarise recent advances in our understanding of the effects of climate change on scleractinian corals and reef fish. Although there is considerable among-species variability in responses to increasing temperature and seawater chemistry, changing temperature regimes are like...

  2. Impacts Of Bleaching On Coral Communities On Artificial Reef Structures In Maldives

    OpenAIRE

    Clark, S.

    2000-01-01

    A research programme to evaluate the feasibility of using artificial reef structures (ARS) to rehabilitate degraded reefs was conducted in Maldives between 1990-1994. Detailed monitoring and analysis of coral recruitment patterns on the ARS over a period of 3.5 years demonstrated that a diverse community of branching corals developed within three years with a similar composition to adjacent reef flats. A warm water anomaly of +3° C occurred in Maldives between late April and May1998 resulting...

  3. Spatial scales of bacterial diversity in cold-water coral reef ecosystems.

    Directory of Open Access Journals (Sweden)

    Sandra Schöttner

    Full Text Available BACKGROUND: Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning. METHODOLOGY/PRINCIPAL FINDINGS: Bacterial community structure, as determined by Automated Ribosomal Intergenic Spacer Analysis (ARISA, was investigated with respect to (i microbial habitat type and (ii coral species and color, as well as the three spatial components (iii geomorphologic reef zoning, (iv reef boundary, and (v reef location. Communities revealed fundamental differences between coral-generated (branch surface, mucus and ambient microbial habitats (seawater, sediments. This habitat specificity appeared pivotal for determining bacterial community shifts over all other study levels investigated. Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types. Within the reef center, no community distinction corresponded to geomorphologic reef zoning for both coral-generated and ambient microbial habitats. Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity. CONCLUSIONS/SIGNIFICANCE: This study presents the first multi-scale survey of bacterial diversity in cold-water coral reefs, spanning a total of five observational levels including three spatial scales. It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has

  4. Spectrographic imaging: A bird's-eye view of the health of coral reefs

    Science.gov (United States)

    Mumby, Peter J.; Chisholm, John R. M.; Clark, Chris D.; Hedley, John D.; Jaubert, Jean

    2001-09-01

    Almost three-quarters of the world's coral reefs are thought to be deteriorating as a consequence of environmental stress. Until now, it has been possible to evaluate reef health only by field survey, which is labour-intensive and time-consuming. Here we map live coral cover from the air by remote imaging, a technique that will enable the state of shallow reefs to be monitored swiftly and over large areas.

  5. Linking Coral Reef Remote Sensing and Field Ecology: It’s a Matter of Scale

    OpenAIRE

    Matthew Q. Lucas; James Goodman

    2014-01-01

    Remote sensing shows potential for assessing biodiversity of coral reefs. Important steps in achieving this objective are better understanding the spectral variability of various reef components and correlating these spectral characteristics with field-based ecological assessments. Here we analyze >9400 coral reef field spectra from southwestern Puerto Rico to evaluate how spectral variability and, more specifically, spectral similarity between species influences estimates of biodiversity....

  6. The trophic importance of algal turfs for coral reef fishes: the crustacean link

    Science.gov (United States)

    Kramer, M. J.; Bellwood, O.; Bellwood, D. R.

    2013-06-01

    On coral reefs, the epilithic algal matrix (EAM) is widely recognised as an important resource for herbivorous and detritivorous fishes. In comparison, little is known of the interaction between benthic carnivores and the EAM, despite the abundance of Crustacea within the EAM. The trophic importance of the EAM to fishes was investigated in Pioneer Bay, Orpheus Island, Great Barrier Reef. Fish densities were quantified using visual and clove oil censuses, and gut content analyses conducted on abundant fish species. Crustaceans were found to be an important dietary category, contributing between 49.5 and 100 % of the gut contents, with harpacticoid copepods being the dominant component. Of the benthic carnivores, the goby Eviota zebrina was found to consume the most harpacticoids with a mean of 249 copepods m-2 day-1. This represents approximately 0.1 % of the available harpacticoid population in the EAM. In a striking comparison, herbivorous parrotfishes were estimated to consume over 12,000 harpacticoids m-2 day-1, over 27 times more than all benthic carnivores surveyed, representing approximately 5.3 % of the available harpacticoid copepod population each day. The high consumption of harpacticoid copepods by benthic carnivores and parrotfishes indicates that harpacticoids form an important trophic link between the EAM and higher trophic levels on coral reefs.

  7. Seasonal variations in the subsurface ultraviolet-B on an inshore Pacific coral reef ecosystem.

    Science.gov (United States)

    Downs, Nathan J; Schouten, Peter W; Parisi, Alfio V

    2013-01-01

    Fringing coral reefs provide a unique opportunity to study shallow aquatic ecosystems. A fringing coral reef system located in close proximity to a developed region was considered in this study. In such an environment, the rate of decay of dissolved organic matter is high and the penetration of higher energy ultraviolet-B (UVB) extends a greater influence on species diversity, particularly upon shallow benthic communities. Results from a 9 month subsurface UVB exposure measurement campaign performed at a site located on the southern Queensland coast (Hervey Bay, 25°S) are presented in this research. For this, a novel dosimetric technique was utilized to measure long-term subsurface UVB exposures. The resultant data set includes exposure measurements made during the significant La Niña event of late 2010 which resulted in unprecedented high sea surface temperatures and severe flooding across eastern Australia, impacting upon the lagoon regions of the Great Barrier Reef and Queensland's southern estuaries, including the study site. The influence of season, diurnal tidal variation, cloud cover and solar zenith angle were analyzed over the campaign period. Mean minimum daylight water depth was found to be the most significant factor influencing subsurface UVB. PMID:23701175

  8. Status of coral reefs in South Asia: Bangladesh, India, Maldives, Sri Lanka

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasuriya, A.; Zahir, H.; Muley, E.V.; Subramanian, B.R.; Venkataraman, K.; Wafar, M.V.M.; Khan, S.M.M.H.; Whittingham, E.

    of loss in reef biodiversity. There is some coral mining, dredging of navigational channels, unsustainable fishing practices, coastal development, and souvenir collection. Recently, blasting of corals to create navigational channels has been stopped... medicines also has adverse impacts. Sri Lanka The major causes of reef degradation are: coral mining, sedimentation, destructive fishing practices (such as blast fishing), the use of bottom set nets, uncontrolled resource exploitation, including harvesting...

  9. Doom and Boom on a Resilient Reef: Climate Change, Algal Overgrowth and Coral Recovery

    OpenAIRE

    Diaz-Pulido, Guillermo; McCook, Laurence J.; Dove, Sophie; Berkelmans, Ray; Roff, George; Kline, David I.; Weeks, Scarla; Richard D. Evans; Williamson, David H.; Hoegh-Guldberg, Ove

    2009-01-01

    Background Coral reefs around the world are experiencing large-scale degradation, largely due to global climate change, overfishing, diseases and eutrophication. Climate change models suggest increasing frequency and severity of warming-induced coral bleaching events, with consequent increases in coral mortality and algal overgrowth. Critically, the recovery of damaged reefs will depend on the reversibility of seaweed blooms, generally considered to depend on grazing of the seaweed, and reple...

  10. Habitat dynamics, marine reserve status, and the decline and recovery of coral reef fish communities

    OpenAIRE

    Williamson, David H; Ceccarelli, Daniela M; Richard D. Evans; Jones, Geoffrey P.; Russ, Garry R

    2014-01-01

    Severe climatic disturbance events often have major impacts on coral reef communities, generating cycles of decline and recovery, and in some extreme cases, community-level phase shifts from coral-to algal-dominated states. Benthic habitat changes directly affect reef fish communities, with low coral cover usually associated with low fish diversity and abundance. No-take marine reserves (NTRs) are widely advocated for conserving biodiversity and enhancing the sustainability of exploited fish ...

  11. Status of the Coral Reefs of Maldives after the Bleaching Event in 1998

    OpenAIRE

    Zahir, H.

    2000-01-01

    A pilot reef monitoring study was conducted in 1998 to assess the extent of coral bleaching in the Maldives. The aims of this monitoring exercise were: 1. To quantitatively document the post-bleaching status of the shallow-water coral communities on the reefs of the north, central and southern regions of Maldives. 2. To estimate bleaching-induced coral mortality by comparing data yielded by the pilot survey with data from previous surveys, especially those sites for which historical dat...

  12. A diverse assemblage of reef corals thriving in a dynamic intertidal reef setting (Bonaparte Archipelago, Kimberley, Australia.

    Directory of Open Access Journals (Sweden)

    Zoe T Richards

    Full Text Available The susceptibility of reef-building corals to climatic anomalies is well documented and a cause of great concern for the future of coral reefs. Reef corals are normally considered to tolerate only a narrow range of climatic conditions with only a small number of species considered heat-tolerant. Occasionally however, corals can be seen thriving in unusually harsh reef settings and these are cause for some optimism about the future of coral reefs. Here we document for the first time a diverse assemblage of 225 species of hard corals occurring in the intertidal zone of the Bonaparte Archipelago, north western Australia. We compare the environmental conditions at our study site (tidal regime, SST and level of turbidity with those experienced at four other more typical tropical reef locations with similar levels of diversity. Physical extremes in the Bonaparte Archipelago include tidal oscillations of up to 8 m, long subaerial exposure times (>3.5 hrs, prolonged exposure to high SST and fluctuating turbidity levels. We conclude the timing of low tide in the coolest parts of the day ameliorates the severity of subaerial exposure, and the combination of strong currents and a naturally high sediment regime helps to offset light and heat stress. The low level of anthropogenic impact and proximity to the Indo-west Pacific centre of diversity are likely to further promote resistance and resilience in this community. This assemblage provides an indication of what corals may have existed in other nearshore locations in the past prior to widespread coastal development, eutrophication, coral predator and disease outbreaks and coral bleaching events. Our results call for a re-evaluation of what conditions are optimal for coral survival, and the Bonaparte intertidal community presents an ideal model system for exploring how species resilience is conferred in the absence of confounding factors such as pollution.

  13. A diverse assemblage of reef corals thriving in a dynamic intertidal reef setting (Bonaparte Archipelago, Kimberley, Australia).

    Science.gov (United States)

    Richards, Zoe T; Garcia, Rodrigo A; Wallace, Carden C; Rosser, Natalie L; Muir, Paul R

    2015-01-01

    The susceptibility of reef-building corals to climatic anomalies is well documented and a cause of great concern for the future of coral reefs. Reef corals are normally considered to tolerate only a narrow range of climatic conditions with only a small number of species considered heat-tolerant. Occasionally however, corals can be seen thriving in unusually harsh reef settings and these are cause for some optimism about the future of coral reefs. Here we document for the first time a diverse assemblage of 225 species of hard corals occurring in the intertidal zone of the Bonaparte Archipelago, north western Australia. We compare the environmental conditions at our study site (tidal regime, SST and level of turbidity) with those experienced at four other more typical tropical reef locations with similar levels of diversity. Physical extremes in the Bonaparte Archipelago include tidal oscillations of up to 8 m, long subaerial exposure times (>3.5 hrs), prolonged exposure to high SST and fluctuating turbidity levels. We conclude the timing of low tide in the coolest parts of the day ameliorates the severity of subaerial exposure, and the combination of strong currents and a naturally high sediment regime helps to offset light and heat stress. The low level of anthropogenic impact and proximity to the Indo-west Pacific centre of diversity are likely to further promote resistance and resilience in this community. This assemblage provides an indication of what corals may have existed in other nearshore locations in the past prior to widespread coastal development, eutrophication, coral predator and disease outbreaks and coral bleaching events. Our results call for a re-evaluation of what conditions are optimal for coral survival, and the Bonaparte intertidal community presents an ideal model system for exploring how species resilience is conferred in the absence of confounding factors such as pollution. PMID:25714443

  14. NOAA's Coral Reef Conservation Program's 2016 Projects that Work Towards Stratefic Goals to Reduce Fishing Impacts on Coral

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2016 the following projects will take place to work towards CRCP's strategic goals to reduce fishing impacts on coral reefs Building GIS Long-term Capacity:...

  15. Global Trajectories of the Long-Term Decline of Coral Reef Ecosystems

    Science.gov (United States)

    Pandolfi, John M.; Bradbury, Roger H.; Sala, Enric; Hughes, Terence P.; Bjorndal, Karen A.; Cooke, Richard G.; McArdle, Deborah; McClenachan, Loren; Newman, Marah J. H.; Paredes, Gustavo; Warner, Robert R.; Jackson, Jeremy B. C.

    2003-08-01

    Degradation of coral reef ecosystems began centuries ago, but there is no global summary of the magnitude of change. We compiled records, extending back thousands of years, of the status and trends of seven major guilds of carnivores, herbivores, and architectural species from 14 regions. Large animals declined before small animals and architectural species, and Atlantic reefs declined before reefs in the Red Sea and Australia, but the trajectories of decline were markedly similar worldwide. All reefs were substantially degraded long before outbreaks of coral disease and bleaching. Regardless of these new threats, reefs will not survive without immediate protection from human exploitation over large spatial scales.

  16. Description and mapping of the coral reefs investigated during the Snellius-II Expedition in Indonesia

    NARCIS (Netherlands)

    Duyl, van F.C.

    1991-01-01

    Macrohabitat distribution, zonation and morphology of coral reefs in the Flores Sea region were investigated. Descriptions of reefs and reef maps are presented, based on large area surveys and aerial photographs. Diving equipment, underwater scooter, depth recorder and different methods of aerial ph

  17. Developing a More "Citizen-Centered" Coral Reef Information System: Engaging the Coral Reef Community To Assess User Needs and Improve Coral Reef Science Communication

    Science.gov (United States)

    Taylor, K.; McCaffrey, M.

    2005-05-01

    With 35 million web pages and 22,000 websites, the U.S. Federal Government through the E-Government Act 2002 directs those who develop and maintain these websites to become more "citizen-centered." One required activity of the act is to "sponsor ongoing dialogue with interested parties (including state, local, and tribal governments, private and non-profit sectors, and the general public) to find innovative ways to use IT to improve the delivery of Government information and services" (Sec 101, 3602). One of the websites that has begun to engage such parties is the NOAA Coral Reef Information System (CoRIS), which is designed to provide the public with access to NOAA's coral reef data and information from a single location. CoRIS has, through two usability workshops conducted by staff from the Coastal Services Center, and a series of stakeholder meetings held in the Fall of 2003 in American Samoa and Hawai'i and the Fall of 2004 in Puerto Rico and the U.S. Virgin Islands, sought to address the needs of users, both internal and external to NOAA. The goal was to select a set of test participants that represented the CoRIS project's targeted users (researchers, managers, general public) and provide an overview of the web site to demonstrate its resources and capabilities. The findings of the workshops and meetings are being used by the CoRIS development team to respond to user needs as part of an iterative process to improve utility and usability of the website and better understand how to present often complex scientific information to address a variety of user needs and local issues. Based on recommendations from the feedback of current and potential users of the CoRIS website from meetings held in the Fall of 2004, the development team has adopted a series of usability requirements to be implemented in the coming year. Participants of the meetings have suggested that CoRIS engage with user communities, including Local Action Strategy (LAS) efforts, to assess user

  18. Seascape-scale trophic links for fish on inshore coral reefs

    Science.gov (United States)

    Davis, Jean P.; Pitt, Kylie A.; Fry, Brian; Olds, Andrew D.; Connolly, Rod M.

    2014-12-01

    It is increasingly accepted that coastal habitats such as inshore coral reefs do not function in isolation but rather as part of a larger habitat network. In the Caribbean, trophic subsidies from habitats adjacent to coral reefs support the diet of reef fishes, but it is not known whether similar trophic links occur on reefs in the Indo-Pacific. Here, we test whether reef fishes in inshore coral, mangrove, and seagrass habitats are supported by trophic links. We used carbon stable isotopes and mathematical mixing models to determine the minimum proportion of resources from mangrove or seagrass habitats in the diet of five fish species from coral reefs at varying distances (0-2,200 m) from these habitats in Moreton Bay, Queensland, eastern Australia. Of the fish species that are more abundant on reefs near to mangroves, Lutjanus russelli and Acanthopagrus australis showed no minimum use of diet sources from mangrove habitat. Siganus fuscescens utilized a minimum of 25-44 % mangrove sources and this contribution increased with the proximity of reefs to mangroves ( R 2 = 0.91). Seagrass or reef flat sources contributed a minimum of 14-78 % to the diet of Diagramma labiosum, a species found in higher abundance on reefs near seagrass beds, but variation in diet among reefs was unrelated to seascape structure. Seagrass or reef flat sources also contributed a minimum of 8-55 % to a fish species found only on reefs ( Pseudolabrus guentheri), indicating that detrital subsidies from these habitats may subsidize fish diet on reefs. These results suggest that carbon sources from multiple habitats contribute to the functioning of inshore coral reef ecosystems and that trophic connectivity between reefs and mangroves may enhance production of a functionally important herbivore.

  19. The DNA of coral reef biodiversity: predicting and protecting genetic diversity of reef assemblages.

    Science.gov (United States)

    Selkoe, Kimberly A; Gaggiotti, Oscar E; Treml, Eric A; Wren, Johanna L K; Donovan, Mary K; Toonen, Robert J

    2016-04-27

    Conservation of ecological communities requires deepening our understanding of genetic diversity patterns and drivers at community-wide scales. Here, we use seascape genetic analysis of a diversity metric, allelic richness (AR), for 47 reef species sampled across 13 Hawaiian Islands to empirically demonstrate that large reefs high in coral cover harbour the greatest genetic diversity on average. We found that a species's life history (e.g. depth range and herbivory) mediates response of genetic diversity to seascape drivers in logical ways. Furthermore, a metric of combined multi-species AR showed strong coupling to species richness and habitat area, quality and stability that few species showed individually. We hypothesize that macro-ecological forces and species interactions, by mediating species turnover and occupancy (and thus a site's mean effective population size), influence the aggregate genetic diversity of a site, potentially allowing it to behave as an apparent emergent trait that is shaped by the dominant seascape drivers. The results highlight inherent feedbacks between ecology and genetics, raise concern that genetic resilience of entire reef communities is compromised by factors that reduce coral cover or available habitat, including thermal stress, and provide a foundation for new strategies for monitoring and preserving biodiversity of entire reef ecosystems. PMID:27122569

  20. The DNA of coral reef biodiversity: predicting and protecting genetic diversity of reef assemblages

    Science.gov (United States)

    Gaggiotti, Oscar E.; Treml, Eric A.; Wren, Johanna L. K.; Donovan, Mary K.; Toonen, Robert J.

    2016-01-01

    Conservation of ecological communities requires deepening our understanding of genetic diversity patterns and drivers at community-wide scales. Here, we use seascape genetic analysis of a diversity metric, allelic richness (AR), for 47 reef species sampled across 13 Hawaiian Islands to empirically demonstrate that large reefs high in coral cover harbour the greatest genetic diversity on average. We found that a species's life history (e.g. depth range and herbivory) mediates response of genetic diversity to seascape drivers in logical ways. Furthermore, a metric of combined multi-species AR showed strong coupling to species richness and habitat area, quality and stability that few species showed individually. We hypothesize that macro-ecological forces and species interactions, by mediating species turnover and occupancy (and thus a site's mean effective population size), influence the aggregate genetic diversity of a site, potentially allowing it to behave as an apparent emergent trait that is shaped by the dominant seascape drivers. The results highlight inherent feedbacks between ecology and genetics, raise concern that genetic resilience of entire reef communities is compromised by factors that reduce coral cover or available habitat, including thermal stress, and provide a foundation for new strategies for monitoring and preserving biodiversity of entire reef ecosystems. PMID:27122569