WorldWideScience

Sample records for coral reef habitats

  1. Digital reef rugosity estimates coral reef habitat complexity.

    Science.gov (United States)

    Dustan, Phillip; Doherty, Orla; Pardede, Shinta

    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 techniques from visual categories to remote sensing have been used to characterize structural complexity at scales from microhabitats to reefscapes. Reef-scale methods either lack quantitative precision or are too time consuming to be routinely practical, while remotely sensed indices are mismatched to the finer scale morphology of coral colonies and reef habitats. In this communication a new digital technique, Digital Reef Rugosity (DRR) is described which utilizes a self-contained water level gauge enabling a diver to quickly and accurately characterize rugosity with non-invasive millimeter scale measurements of coral reef surface height at decimeter intervals along meter scale transects. The precise measurements require very little post-processing and are easily imported into a spreadsheet for statistical analyses and modeling. To assess its applicability we investigated the relationship between DRR and fish community structure at four coral reef sites on Menjangan Island off the northwest corner of Bali, Indonesia and one on mainland Bali to the west of Menjangan Island; our findings show a positive relationship between DRR and fish diversity. Since structural complexity drives key ecological processes on coral reefs, we consider that DRR may become a useful quantitative community-level descriptor to characterize reef complexity.

  2. Palmyra Atoll coral reef habitat mapping completion report

    OpenAIRE

    2010-01-01

    The United States Coral Reef Task Force (USCRTF) was established in 1998 by Presidential Executive Order 13089 to lead U.S. efforts to preserve and protect coral reef ecosystems. Current, accurate, and consistent maps greatly enhance efforts to preserve and manage coral reef ecosystems. With comprehensive maps and habitat assessments, coral reef managers can be more effective in designing and implementing a variety of conservation measures, including: • Long-term monitoring programs with ...

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

    Science.gov (United States)

    McMahon, Kelton W; Berumen, Michael L; Thorrold, Simon R

    2012-09-18

    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 configuration 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.

  4. 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.

  5. Coral reef habitat response to climate change scenarios.

    Directory of Open Access Journals (Sweden)

    Lauren A Freeman

    Full Text Available Coral reef ecosystems are threatened by both climate change and direct anthropogenic stress. Climate change will alter the physico-chemical environment that reefs currently occupy, leaving only limited regions that are conducive to reef habitation. Identifying these regions early may aid conservation efforts and inform decisions to transplant particular coral species or groups. Here a species distribution model (Maxent is used to describe habitat suitable for coral reef growth. Two climate change scenarios (RCP4.5, RCP8.5 from the National Center for Atmospheric Research's Community Earth System Model were used with Maxent to determine environmental suitability for corals (order Scleractinia. Environmental input variables best at representing the limits of suitable reef growth regions were isolated using a principal component analysis. Climate-driven changes in suitable habitat depend strongly on the unique region of reefs used to train Maxent. Increased global habitat loss was predicted in both climate projections through the 21(st century. A maximum habitat loss of 43% by 2100 was predicted in RCP4.5 and 82% in RCP8.5. When the model is trained solely with environmental data from the Caribbean/Atlantic, 83% of global habitat was lost by 2100 for RCP4.5 and 88% was lost for RCP8.5. Similarly, global runs trained only with Pacific Ocean reefs estimated that 60% of suitable habitat would be lost by 2100 in RCP4.5 and 90% in RCP8.5. When Maxent was trained solely with Indian Ocean reefs, suitable habitat worldwide increased by 38% in RCP4.5 by 2100 and 28% in RCP8.5 by 2050. Global habitat loss by 2100 was just 10% for RCP8.5. This projection suggests that shallow tropical sites in the Indian Ocean basin experience conditions today that are most similar to future projections of worldwide conditions. Indian Ocean reefs may thus be ideal candidate regions from which to select the best strands of coral for potential re-seeding efforts.

  6. Coral reef habitat response to climate change scenarios.

    Science.gov (United States)

    Freeman, Lauren A; Kleypas, Joan A; Miller, Arthur J

    2013-01-01

    Coral reef ecosystems are threatened by both climate change and direct anthropogenic stress. Climate change will alter the physico-chemical environment that reefs currently occupy, leaving only limited regions that are conducive to reef habitation. Identifying these regions early may aid conservation efforts and inform decisions to transplant particular coral species or groups. Here a species distribution model (Maxent) is used to describe habitat suitable for coral reef growth. Two climate change scenarios (RCP4.5, RCP8.5) from the National Center for Atmospheric Research's Community Earth System Model were used with Maxent to determine environmental suitability for corals (order Scleractinia). Environmental input variables best at representing the limits of suitable reef growth regions were isolated using a principal component analysis. Climate-driven changes in suitable habitat depend strongly on the unique region of reefs used to train Maxent. Increased global habitat loss was predicted in both climate projections through the 21(st) century. A maximum habitat loss of 43% by 2100 was predicted in RCP4.5 and 82% in RCP8.5. When the model is trained solely with environmental data from the Caribbean/Atlantic, 83% of global habitat was lost by 2100 for RCP4.5 and 88% was lost for RCP8.5. Similarly, global runs trained only with Pacific Ocean reefs estimated that 60% of suitable habitat would be lost by 2100 in RCP4.5 and 90% in RCP8.5. When Maxent was trained solely with Indian Ocean reefs, suitable habitat worldwide increased by 38% in RCP4.5 by 2100 and 28% in RCP8.5 by 2050. Global habitat loss by 2100 was just 10% for RCP8.5. This projection suggests that shallow tropical sites in the Indian Ocean basin experience conditions today that are most similar to future projections of worldwide conditions. Indian Ocean reefs may thus be ideal candidate regions from which to select the best strands of coral for potential re-seeding efforts.

  7. Habitat associations of juvenile fish at Ningaloo Reef, Western Australia: the importance of coral and algae.

    Science.gov (United States)

    Wilson, Shaun K; Depczynski, Martial; Fisher, Rebecca; Holmes, Thomas H; O'Leary, Rebecca A; Tinkler, Paul

    2010-12-07

    Habitat specificity plays a pivotal role in forming community patterns in coral reef fishes, yet considerable uncertainty remains as to the extent of this selectivity, particularly among newly settled recruits. Here we quantified habitat specificity of juvenile coral reef fish at three ecological levels; algal meadows vs. coral reefs, live vs. dead coral and among different coral morphologies. In total, 6979 individuals from 11 families and 56 species were censused along Ningaloo Reef, Western Australia. Juvenile fishes exhibited divergence in habitat use and specialization among species and at all study scales. Despite the close proximity of coral reef and algal meadows (10's of metres) 25 species were unique to coral reef habitats, and seven to algal meadows. Of the seven unique to algal meadows, several species are known to occupy coral reef habitat as adults, suggesting possible ontogenetic shifts in habitat use. Selectivity between live and dead coral was found to be species-specific. In particular, juvenile scarids were found predominantly on the skeletons of dead coral whereas many damsel and butterfly fishes were closely associated with live coral habitat. Among the coral dependent species, coral morphology played a key role in juvenile distribution. Corymbose corals supported a disproportionate number of coral species and individuals relative to their availability, whereas less complex shapes (i.e. massive & encrusting) were rarely used by juvenile fish. Habitat specialisation by juvenile species of ecological and fisheries importance, for a variety of habitat types, argues strongly for the careful conservation and management of multiple habitat types within marine parks, and indicates that the current emphasis on planning conservation using representative habitat areas is warranted. Furthermore, the close association of many juvenile fish with corals susceptible to climate change related disturbances suggests that identifying and protecting reefs

  8. Habitat associations of juvenile fish at Ningaloo Reef, Western Australia: the importance of coral and algae.

    Directory of Open Access Journals (Sweden)

    Shaun K Wilson

    Full Text Available Habitat specificity plays a pivotal role in forming community patterns in coral reef fishes, yet considerable uncertainty remains as to the extent of this selectivity, particularly among newly settled recruits. Here we quantified habitat specificity of juvenile coral reef fish at three ecological levels; algal meadows vs. coral reefs, live vs. dead coral and among different coral morphologies. In total, 6979 individuals from 11 families and 56 species were censused along Ningaloo Reef, Western Australia. Juvenile fishes exhibited divergence in habitat use and specialization among species and at all study scales. Despite the close proximity of coral reef and algal meadows (10's of metres 25 species were unique to coral reef habitats, and seven to algal meadows. Of the seven unique to algal meadows, several species are known to occupy coral reef habitat as adults, suggesting possible ontogenetic shifts in habitat use. Selectivity between live and dead coral was found to be species-specific. In particular, juvenile scarids were found predominantly on the skeletons of dead coral whereas many damsel and butterfly fishes were closely associated with live coral habitat. Among the coral dependent species, coral morphology played a key role in juvenile distribution. Corymbose corals supported a disproportionate number of coral species and individuals relative to their availability, whereas less complex shapes (i.e. massive & encrusting were rarely used by juvenile fish. Habitat specialisation by juvenile species of ecological and fisheries importance, for a variety of habitat types, argues strongly for the careful conservation and management of multiple habitat types within marine parks, and indicates that the current emphasis on planning conservation using representative habitat areas is warranted. Furthermore, the close association of many juvenile fish with corals susceptible to climate change related disturbances suggests that identifying and

  9. 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...

  10. Effects of trap fishing on coral reefs and associated habitats in the Florida Keys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We conducted surveys of trap distributions, targeted habitats, trap damage to coral reefs and associated habitats, and spatial/temporal distribution of catches....

  11. Effects of trap fishing on coral reefs and associated habitats in the US Caribbean

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We are conducting surveys of trap distributions, targeted habitats, trap damage to coral reefs and associated habitats, and spatial/temporal distribution of catches....

  12. Suitable environmental ranges for potential coral reef habitats in the tropical ocean.

    Science.gov (United States)

    Guan, Yi; Hohn, Sönke; Merico, Agostino

    2015-01-01

    Coral reefs are found within a limited range of environmental conditions or tolerance limits. Estimating these limits is a critical prerequisite for understanding the impacts of climate change on the biogeography of coral reefs. Here we used the diagnostic model ReefHab to determine the current environmental tolerance limits for coral reefs and the global distribution of potential coral reef habitats as a function of six factors: temperature, salinity, nitrate, phosphate, aragonite saturation state, and light. To determine these tolerance limits, we extracted maximum and minimum values of all environmental variables in corresponding locations where coral reefs are present. We found that the global, annually averaged tolerance limits for coral reefs are 21.7-29.6 °C for temperature, 28.7-40.4 psu for salinity, 4.51 μmol L-1 for nitrate, 0.63 μmol L-1 for phosphate, and 2.82 for aragonite saturation state. The averaged minimum light intensity in coral reefs is 450 μmol photons m-2 s-1. The global area of potential reef habitats calculated by the model is 330.5 × 103 km2. Compared with previous studies, the tolerance limits for temperature, salinity, and nutrients have not changed much, whereas the minimum value of aragonite saturation in coral reef waters has decreased from 3.28 to 2.82. The potential reef habitat area calculated with ReefHab is about 121×103 km2 larger than the area estimated from the charted reefs, suggesting that the growth potential of coral reefs is higher than currently observed.

  13. Habitat use by fishes in coral reefs, seagrass beds and mangrove habitats in the Philippines.

    Science.gov (United States)

    Honda, Kentaro; Nakamura, Yohei; Nakaoka, Masahiro; Uy, Wilfredo H; Fortes, Miguel D

    2013-01-01

    Understanding the interconnectivity of organisms among different habitats is a key requirement for generating effective management plans in coastal ecosystems, particularly when determining component habitat structures in marine protected areas. To elucidate the patterns of habitat use by fishes among coral, seagrass, and mangrove habitats, and between natural and transplanted mangroves, visual censuses were conducted semiannually at two sites in the Philippines during September and March 2010-2012. In total, 265 species and 15,930 individuals were recorded. Species richness and abundance of fishes were significantly higher in coral reefs (234 species, 12,306 individuals) than in seagrass (38 species, 1,198 individuals) and mangrove (47 species, 2,426 individuals) habitats. Similarity tests revealed a highly significant difference among the three habitats. Fishes exhibited two different strategies for habitat use, inhabiting either a single (85.6% of recorded species) or several habitats (14.4%). Some fish that utilized multiple habitats, such as Lutjanus monostigma and Parupeneus barberinus, showed possible ontogenetic habitat shifts from mangroves and/or seagrass habitats to coral reefs. Moreover, over 20% of commercial fish species used multiple habitats, highlighting the importance of including different habitat types within marine protected areas to achieve efficient and effective resource management. Neither species richness nor abundance of fishes significantly differed between natural and transplanted mangroves. In addition, 14 fish species were recorded in a 20-year-old transplanted mangrove area, and over 90% of these species used multiple habitats, further demonstrating the key role of transplanted mangroves as a reef fish habitat in this region.

  14. Mingulay reef complex: An interdisciplinary study of cold-water coral habitat, hydrography and biodiversity

    NARCIS (Netherlands)

    Roberts, J.M.; Davies, A.J.; Henry, L.A.; Dodds, L.A.; Duineveld, G.C.A.; Lavaleye, M.S.S.; Maier, C.; van Soest, R.W.M.; Bergman, M.J.N.; Hühnerbach, V.; Huvenne, V.A.I.; Sinclair, D.J.; Watmough, T.; Long, D.; Green, S.L.; van Haren, H.

    2009-01-01

    The Mingulay reef complex in the Sea of the Hebrides west of Scotland was first mapped in 2003 with a further survey in 2006 revealing previously unknown live coral reef areas at 120 to 190 m depth. Habitat mapping confirmed that distinctive mounded bathymetry was formed by reefs of Lophelia pertusa

  15. Determining the extent and characterizing coral reef habitats of the northern latitudes of the Florida Reef Tract (Martin County).

    Science.gov (United States)

    Walker, Brian K; Gilliam, David S

    2013-01-01

    Climate change has recently been implicated in poleward shifts of many tropical species including corals; thus attention focused on higher-latitude coral communities is warranted to investigate possible range expansions and ecosystem shifts due to global warming. As the northern extension of the Florida Reef Tract (FRT), the third-largest barrier reef ecosystem in the world, southeast Florida (25-27° N latitude) is a prime region to study such effects. Most of the shallow-water FRT benthic habitats have been mapped, however minimal data and limited knowledge exist about the coral reef communities of its northernmost reaches off Martin County. First benthic habitat mapping was conducted using newly acquired high resolution LIDAR bathymetry and aerial photography where possible to map the spatial extent of coral reef habitats. Quantitative data were collected to characterize benthic cover and stony coral demographics and a comprehensive accuracy assessment was performed. The data were then analyzed in a habitat biogeography context to determine if a new coral reef ecosystem region designation was warranted. Of the 374 km(2) seafloor mapped, 95.2% was Sand, 4.1% was Coral Reef and Colonized Pavement, and 0.7% was Other Delineations. Map accuracy assessment yielded an overall accuracy of 94.9% once adjusted for known map marginal proportions. Cluster analysis of cross-shelf habitat type and widths indicated that the benthic habitats were different than those further south and warranted designation of a new coral reef ecosystem region. Unlike the FRT further south, coral communities were dominated by cold-water tolerant species and LIDAR morphology indicated no evidence of historic reef growth during warmer climates. Present-day hydrographic conditions may be inhibiting poleward expansion of coral communities along Florida. This study provides new information on the benthic community composition of the northern FRT, serving as a baseline for future community shift and

  16. Determining the extent and characterizing coral reef habitats of the northern latitudes of the Florida Reef Tract (Martin County.

    Directory of Open Access Journals (Sweden)

    Brian K Walker

    Full Text Available Climate change has recently been implicated in poleward shifts of many tropical species including corals; thus attention focused on higher-latitude coral communities is warranted to investigate possible range expansions and ecosystem shifts due to global warming. As the northern extension of the Florida Reef Tract (FRT, the third-largest barrier reef ecosystem in the world, southeast Florida (25-27° N latitude is a prime region to study such effects. Most of the shallow-water FRT benthic habitats have been mapped, however minimal data and limited knowledge exist about the coral reef communities of its northernmost reaches off Martin County. First benthic habitat mapping was conducted using newly acquired high resolution LIDAR bathymetry and aerial photography where possible to map the spatial extent of coral reef habitats. Quantitative data were collected to characterize benthic cover and stony coral demographics and a comprehensive accuracy assessment was performed. The data were then analyzed in a habitat biogeography context to determine if a new coral reef ecosystem region designation was warranted. Of the 374 km(2 seafloor mapped, 95.2% was Sand, 4.1% was Coral Reef and Colonized Pavement, and 0.7% was Other Delineations. Map accuracy assessment yielded an overall accuracy of 94.9% once adjusted for known map marginal proportions. Cluster analysis of cross-shelf habitat type and widths indicated that the benthic habitats were different than those further south and warranted designation of a new coral reef ecosystem region. Unlike the FRT further south, coral communities were dominated by cold-water tolerant species and LIDAR morphology indicated no evidence of historic reef growth during warmer climates. Present-day hydrographic conditions may be inhibiting poleward expansion of coral communities along Florida. This study provides new information on the benthic community composition of the northern FRT, serving as a baseline for future

  17. Are artificial reefs surrogates of natural habitats for corals and fish in Dubai, United Arab Emirates?

    Science.gov (United States)

    Burt, J.; Bartholomew, A.; Usseglio, P.; Bauman, A.; Sale, P. F.

    2009-09-01

    Artificial reefs are often promoted as mitigating human impacts in coastal ecosystems and enhancing fisheries; however, evidence supporting their benefits is equivocal. Such structures must be compared with natural reefs in order to assess their performance, but past comparisons typically examined artificial structures that were too small, or were immature, relative to the natural reefs. We compared coral and fish communities on two large (>400,000 m3) and mature (>25 year) artificial reefs with six natural coral patches. Coral cover was higher on artificial reefs (50%) than in natural habitats (31%), but natural coral patches contained higher species richness (29 vs. 20) and coral diversity ( H' = 2.3 vs. 1.8). Multivariate analyses indicated strong differences between coral communities in natural and artificial habitats. Fish communities were sampled seasonally for 1 year. Multivariate fish communities differed significantly among habitat types in the summer and fall, but converged in the winter and spring. Univariate analysis indicated that species richness and abundance were stable throughout the year on natural coral patches but increased significantly in the summer on artificial reefs compared with the winter and spring, explaining the multivariate changes in community structure. The increased summer abundance on artificial reefs was mainly due to adult immigration. Piscivores were much more abundant in the fall than in the winter or spring on artificial reefs, but had low and stable abundance throughout the year in natural habitats. It is likely that the decreased winter and spring abundance of fish on the artificial reefs resulted from both predation and emigration. These results indicate that large artificial reefs can support diverse and abundant coral and fish communities. However, these communities differ structurally and functionally from those in natural habitats, and they should not be considered as replacements for natural coral and fish communities.

  18. mkk_benthic_habitats - Benthic habitat of the coral reef ecosystem on the south shore of Molokai Hawaii.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A benthic habitat polygon coverage has been created of the coral reef ecosystem on the south shore of Moloka'i. Polygons were hand-digitized from visual...

  19. Understanding the murky history of the Coral Triangle: Miocene corals and reef habitats in East Kalimantan (Indonesia)

    Science.gov (United States)

    Santodomingo, Nadiezhda; Renema, Willem; Johnson, Kenneth G.

    2016-09-01

    Studies on ancient coral communities living in marginal conditions, including low light, high turbidity, extreme temperatures, or high nutrients, are important to understand the current structure of reefs and how they could potentially respond to global changes. The main goal of this study was to document the rich and well-preserved fossil coral fauna preserved in Miocene exposures of the Kutai Basin in East Kalimantan, Indonesia. Our collections include almost forty thousand specimens collected from 47 outcrops. Seventy-nine genera and 234 species have been identified. Three different coral assemblages were found corresponding to small patch reefs that developed under the influence of high siliciclastic inputs from the Mahakam Delta. Coral assemblages vary in richness, structure, and composition. Platy coral assemblages were common until the Serravallian (Middle Miocene), while branching coral assemblages became dominant in the Tortonian (Late Miocene). By the late Tortonian massive coral assemblages dominated, similar to modern-style coral framework. Our results suggest that challenging habitats, such as the Miocene turbid habitats of East Kalimantan, might have played an important role during the early diversification of the Coral Triangle by hosting a pool of resilient species more likely to survive the environmental changes that have affected this region since the Cenozoic. Further research that integrates fossil and recent turbid habitats may provide a glimpse into the dynamics and future of coral reefs as "typical" clear-water reefs continue to decline in most regions.

  20. Fitness consequences of habitat variability, trophic position, and energy allocation across the depth distribution of a coral-reef fish

    Science.gov (United States)

    Goldstein, E. D.; D'Alessandro, E. K.; Sponaugle, S.

    2017-09-01

    Environmental clines such as latitude and depth that limit species' distributions may be associated with gradients in habitat suitability that can affect the fitness of an organism. With the global loss of shallow-water photosynthetic coral reefs, mesophotic coral ecosystems ( 30-150 m) may be buffered from some environmental stressors, thereby serving as refuges for a range of organisms including mobile obligate reef dwellers. Yet habitat suitability may be diminished at the depth boundary of photosynthetic coral reefs. We assessed the suitability of coral-reef habitats across the majority of the depth distribution of a common demersal reef fish ( Stegastes partitus) ranging from shallow shelf (SS, reefs are suitable habitats for demersal reef fish and may be important refuges for organisms common on declining shallow coral reefs.

  1. Contrasting effects of habitat loss and fragmentation on coral-associated reef fishes.

    Science.gov (United States)

    Bonin, Mary C; Almany, Glenn R; Jones, Geoffrey P

    2011-07-01

    Disturbance can result in the fragmentation and/or loss of suitable habitat, both of which can have important consequences for survival, species interactions, and resulting patterns of local diversity. However, effects of habitat loss and fragmentation are typically confounded during disturbance events, and previous attempts to determine their relative significance have proved ineffective. Here we experimentally manipulated live coral habitats to examine the potential independent and interactive effects of habitat loss and fragmentation on survival, abundance, and species richness of recruitment-stage, coral-associated reef fishes. Loss of 75% of live coral from experimental reefs resulted in low survival of a coral-associated damselfish and low abundance and richness of other recruits 16 weeks after habitat manipulations. In contrast, fragmentation had positive effects on damselfish survival and resulted in greater abundance and species richness of other recruits. We hypothesize that spacing of habitat through fragmentation weakens competition within and among species. Comparison of effect sizes over the course of the study period revealed that, in the first six weeks following habitat manipulations, the positive effects of fragmentation were at least four times stronger than the effects of habitat loss. This initial positive effect of fragmentation attenuated considerably after 16 weeks, whereas the negative effects of habitat loss increased in strength over time. There was little indication that the amount of habitat influenced the magnitude of the habitat fragmentation effect. Numerous studies have reported dramatic declines in coral reef fish abundance and diversity in response to disturbances that cause the loss and fragmentation of coral habitats. Our results suggest that these declines occur as a result of habitat loss, not habitat fragmentation. Positive fragmentation effects may actually buffer against the negative effects of habitat loss and contribute

  2. Coral reef mesopredators switch prey, shortening food chains, in response to habitat degradation.

    Science.gov (United States)

    Hempson, Tessa N; Graham, Nicholas A J; MacNeil, M Aaron; Williamson, David H; Jones, Geoffrey P; Almany, Glenn R

    2017-04-01

    Diet specificity is likely to be the key predictor of a predator's vulnerability to changing habitat and prey conditions. Understanding the degree to which predatory coral reef fishes adjust or maintain prey choice, in response to declines in coral cover and changes in prey availability, is critical for predicting how they may respond to reef habitat degradation. Here, we use stable isotope analyses to characterize the trophic structure of predator-prey interactions on coral reefs of the Keppel Island Group on the southern Great Barrier Reef, Australia. These reefs, previously typified by exceptionally high coral cover, have recently lost much of their coral cover due to coral bleaching and frequent inundation by sediment-laden, freshwater flood plumes associated with increased rainfall patterns. Long-term monitoring of these reefs demonstrates that, as coral cover declined, there has been a decrease in prey biomass, and a shift in dominant prey species from pelagic plankton-feeding damselfishes to territorial benthic algal-feeding damselfishes, resulting in differences in the principal carbon pathways in the food web. Using isotopes, we tested whether this changing prey availability could be detected in the diet of a mesopredator (coral grouper, Plectropomus maculatus). The δ(13)C signature in grouper tissue in the Keppel Islands shifted from a more pelagic to a more benthic signal, demonstrating a change in carbon sources aligning with the change in prey availability due to habitat degradation. Grouper with a more benthic carbon signature were also feeding at a lower trophic level, indicating a shortening in food chains. Further, we found a decline in the coral grouper population accompanying a decrease in total available prey biomass. Thus, while the ability to adapt diets could ameliorate the short-term impacts of habitat degradation on mesopredators, long-term effects may negatively impact mesopredator populations and alter the trophic structure of coral reef

  3. 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

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

    Directory of Open Access Journals (Sweden)

    Alejandra Hernandez-Agreda

    2016-07-01

    Full Text Available 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.

  5. Mangrove habitats provide refuge from climate change for reef-building corals

    Directory of Open Access Journals (Sweden)

    K. K. Yates

    2014-03-01

    Full Text Available Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business as usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH, slows coral growth, and may cause loss of reef structure. Management strategies include establishment of marine protected areas with environmental conditions that promote reef resiliency. However, few resilient reefs have been identified, and resiliency factors are poorly defined. Here we characterize the first natural, non-reef, coral refuge from thermal stress and ocean acidification and identify resiliency factors for mangrove–coral habitats. We measured diurnal and seasonal variations in temperature, salinity, photosynthetically active radiation (PAR, and seawater chemistry; characterized substrate parameters; and examined water circulation patterns in mangrove communities where scleractinian corals are growing attached to and under mangrove prop roots in Hurricane Hole, St. John, US Virgin Islands. Additionally, we inventoried the coral species and quantified incidences of coral bleaching, mortality and recovery for two major reef-building corals, Colpophyllia natans and Diploria labyrinthiformis, growing in mangrove shaded and exposed (unshaded areas. At least 33 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies was living shaded by mangroves, and no shaded colonies bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies bleached. A combination of substrate and habitat heterogeniety, proximity of different habitat types

  6. Mangrove habitats provide refuge from climate change for reef-building corals

    Science.gov (United States)

    Yates, K. K.; Rogers, C. S.; Herlan, J. J.; Brooks, G. R.; Smiley, N. A.; Larson, R. A.

    2014-03-01

    Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business as usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH, slows coral growth, and may cause loss of reef structure. Management strategies include establishment of marine protected areas with environmental conditions that promote reef resiliency. However, few resilient reefs have been identified, and resiliency factors are poorly defined. Here we characterize the first natural, non-reef, coral refuge from thermal stress and ocean acidification and identify resiliency factors for mangrove-coral habitats. We measured diurnal and seasonal variations in temperature, salinity, photosynthetically active radiation (PAR), and seawater chemistry; characterized substrate parameters; and examined water circulation patterns in mangrove communities where scleractinian corals are growing attached to and under mangrove prop roots in Hurricane Hole, St. John, US Virgin Islands. Additionally, we inventoried the coral species and quantified incidences of coral bleaching, mortality and recovery for two major reef-building corals, Colpophyllia natans and Diploria labyrinthiformis, growing in mangrove shaded and exposed (unshaded) areas. At least 33 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR) from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies was living shaded by mangroves, and no shaded colonies bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies bleached. A combination of substrate and habitat heterogeniety, proximity of different habitat types, hydrographic

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

    OpenAIRE

    2012-01-01

    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 ...

  8. Comparative Effects of Different Disturbances in Coral Reef Habitats in Moorea, French Polynesia

    Directory of Open Access Journals (Sweden)

    Mélanie L. Trapon

    2011-01-01

    Full Text Available Degradation and loss of critical coastal habitats has significant ramifications for marine fisheries, such that knowledge of changes in habitat quality and quantity are fundamental to effective ecosystem management. This study explores changes in the structure of coral reef habitats, specifically changes in coral cover and composition, in Moorea, French Polynesia, to assess the independent and combined effects of different disturbances since 1979. During this period, reefs on the north coast have been subject to coral bleaching, severe tropical storms, as well as outbreaks of Acanthaster. Coral cover varied significantly among years, showing marked declines during some, but not all, disturbances. The greatest rates of coral loss coincided with outbreaks of A. planci. Moreover, successive disturbances have had differential effects among coral genera, leading to strong directional shifts in coral composition. Acropora is declining in abundance and coral assemblages are becoming increasingly dominated by Pocillopora and Porites. Observed changes in the cover and composition of corals are likely to have further significant impacts on the reef fish assemblages. Given that significant disturbances have been mostly associated with outbreaks of A. planci, rather than climate change, effective ecosystem management may reduce and/or delay impending effects of climate change.

  9. Among-habitat algal selectivity by browsing herbivores on an inshore coral reef

    Science.gov (United States)

    Loffler, Zoe; Bellwood, David R.; Hoey, Andrew S.

    2015-06-01

    Understanding how the impact of different herbivores varies spatially on coral reefs is important in qualifying the resistance of coral reefs to disturbance events and identifying the processes that structure algal communities. We used assays of six common macroalgae ( Acanthophora spicifera, Caulerpa taxifolia, Galaxaura rugosa, Laurencia sp. Sargassum sp., and Turbinaria ornata) and remote underwater video cameras to quantify herbivory in two habitats (reef crest and slope) across multiple sites on Orpheus Island, Great Barrier Reef. Rates of herbivory varied among macroalgal taxa, habitats, and sites. Reductions in algal biomass were greatest for Sargassum sp. (36 % 4 h-1), intermediate for A. spicifera, Laurencia sp., C. taxifolia, and T. ornata (17-33 % 4 h-1) and lowest for G. rugosa (6 % 4 h-1). Overall, rates of herbivory were generally greater on the reef crest (30 % 4 h-1) than the reef slope (21 % 4 h-1). This difference in rates of herbivory coincided with a marked shift in the dominant herbivores between habitats. Kyphosus vaigiensis, despite only feeding on three species of macroalgae ( Sargassum sp., T. ornata, and A. spicifera), was responsible for 34 % of all bites recorded on the reef crest yet did not take a single bite from algae on the reef slope. In contrast, Siganus doliatus took bites on every species of algae in both habitats, accounting for 40 % of bites on the reef crest and 74 % of all bites recorded on the reef slope. This difference in the number of macroalgal species targeted by herbivores and the habitat/s in which they feed adds another dimension of complexity to our understanding of coral reef herbivore dynamics.

  10. 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

    2014-01-01

    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 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

  11. 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.

  12. Coral reef encruster communities and carbonate production in cryptic and exposed coral reef habitats along a gradient of terrestrial disturbance

    Science.gov (United States)

    Mallela, J.

    2007-12-01

    Encrusting calcareous organisms such as bryozoans, crustose coralline algae (CCA), foraminiferans, and serpulid worms are integral components of tropical framework-building reefs. They can contribute calcium carbonate to the reef framework, stabilise the substrate, and promote larval recruitment of other framework-building species (e.g. coral recruits). The percentage cover of encrusting organisms and their rates of carbonate production (g m-2 year-1) were assessed at four sites within a coastal embayment, along a gradient of riverine influence (high-low). As the orientation and type of substrate is thought to influence recruitment of encrusting organisms, organisms recruiting to both natural (the underside of platy corals) and experimental substrates were assessed. The effect of substrate exposure under different levels of riverine influence was assessed by orientating experimental substrates to mimic cryptic and exposed reef habitats (downwards-facing vs upwards-facing tiles) at each site. Cryptic experimental tiles supported similar encruster assemblages to those recruiting to the underneath (cryptic side) of platy corals, suggesting that tiles can be used as an experimental substrate to assess encruster recruitment in reef systems. Encruster cover, in particular CCA, and carbonate production was significantly higher at low-impact (clear water), high wave energy sites when compared to highly riverine impacted (turbid water), low wave energy sites. Cryptically orientated substrates supported a greater diversity of encrusting organisms, in particular serpulid worms and bryozoans. The inverse relationships observed between riverine inputs and encrusters (total encruster cover and carbonate production) have implications for both the current and future rates and styles of reefal framework production.

  13. New Records of Atypical Coral Reef Habitat in the Kimberley, Australia

    Directory of Open Access Journals (Sweden)

    Z. T. Richards

    2013-01-01

    Full Text Available New surveys of the Kimberley Nearshore Bioregion are beginning to fill knowledge gaps about the region’s marine biodiversity and the national and international conservation significance of this little-known tropical reef system. Here we report the recent finding of two unique coral habitats documented at Adele Island and Long Reef during the Woodside 2009/2010 Collection Project surveys. Firstly, we report the finding of a subtidal zone of mixed corallith and rhodolith habitat which appears on current records, to be unprecedented in Australia. Secondly, we report the discovery of an atypical Organ Pipe Coral habitat zone and provide empirical evidence that this commercially valuable species reaches an unparalleled level of benthic cover. We provide additional details about the wider hard and soft coral assemblages associated with these unique habitats; discuss the potential biological causes and consequences of them, and make recommendations to benefit their conservation.

  14. Benthic communities at two remote Pacific coral reefs: effects of reef habitat, depth, and wave energy gradients on spatial patterns

    Directory of Open Access Journals (Sweden)

    Gareth J. Williams

    2013-05-01

    Full Text Available 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%, larger fleshy macroalgae were virtually absent at Kingman (<1% and rare at Palmyra (0.7–9.3%. Hard coral cover was higher, but with low diversity, in more sheltered habitats such as Palmyra’s backreef and Kingman’s patch reefs. Almost exclusive dominance by slow-growing Porites on Kingman’s patch reefs provides indirect evidence of competitive exclusion, probably late in a successional sequence. In contrast, the more exposed forereef habitats at both Kingman and Palmyra had higher coral diversity and were characterized by fast-growing corals (e.g., Acropora and Pocillopora, indicative of more dynamic environments. In general at both locations, soft coral cover increased with depth, likely reflecting increasingly efficient heterotrophic abilities. CCA and fleshy macroalgae cover decreased with depth, likely due to reduced light. Cover of other calcified macroalgae, predominantly Halimeda, increased with depth. This likely reflects the ability of many calcifying macroalgae to efficiently harvest light at deeper depths, in combination with an increased nutrient supply from upwelling promoting growth. At Palmyra, patterns of hard coral cover with depth were inconsistent, but cover peaked at mid-depths at Kingman. On Kingman’s forereef, benthic community composition was strongly related to wave energy, with hard coral cover decreasing and becoming more spatially clustered with increased wave energy, likely as a result of physical damage leading to

  15. Seasonal and ontogenetic patterns of habitat use in coral reef fish juveniles

    OpenAIRE

    Mellin, Camille; Kulbicki, Michel; Ponton, Dominique

    2007-01-01

    We investigated the diversity of patterns of habitat use by juveniles of coral reef fishes according to seasons and at two spatial scales (10-100 m and 1-10 km). We conducted underwater visual censuses in New Caledonia's Lagoon between 1986 and 2001. Co-inertia analyses highlighted the importance of mid-shelf habitats at large spatial scale (1-10 km) and of sandy and vegetated habitats at small spatial scale (10-100 m) for most juveniles. Among all juvenile species, 53% used different habitat...

  16. Habitat, Fauna, and Conservation of Florida's Deep-Water Coral Reefs

    Science.gov (United States)

    Reed, J. K.; Pomponi, S. A.; Messing, C. G.; Brooke, S.

    2008-05-01

    ,000 individual deep-water lithoherms may occur on the Blake Plateau and Straits of Florida, perhaps exceeding the areal extent of all the shallow-water reefs of the southeastern U.S. Our research program has provided data on the status of knowledge concerning these deep-reef habitats to the South Atlantic Fishery Management Council (SAFMC). Currently pending is a proposal by the SAFMC for a deep- water coral Habitat Area of Particular Concern (HAPC) that would extend from North Carolina to south Florida (78,888 km2) to protect these diverse and irreplaceable resources from destructive fishing activities such as bottom trawling. Deep-water reefs worldwide have been severely impacted by bottom trawling, including the deep-water Oculina coral reefs off central eastern Florida, which are structurally similar to the Lophelia reefs. Over a 30-year period, up to 99% of unprotected portions of the Oculina reefs were destroyed by rock shrimp trawling, whereas reefs designated as the Oculina HAPC in 1984 were protected from trawling and long-lines and are still relatively healthy. Numerous fisheries may target the deep-water Lophelia reef habitat including royal red shrimp, golden crab, and various fin fish.

  17. Simulation of global ocean acidification and chemical habitats of shallow- and cold-water coral reefs

    Directory of Open Access Journals (Sweden)

    Mei-Di Zheng

    2014-12-01

    Full Text Available Using the UVic Earth System Model, this study simulated the change of seawater chemistry and analyzed the chemical habitat surrounding shallow- and cold-water coral reefs from the year 1800 to 2300 employing RCP2.6, RCP4.5, RCP6.0, and RCP8.5 scenarios. The model results showed that the global ocean will continue to absorb atmospheric CO2. Global mean surface ocean temperature will rise 1.1–2.8 K at the end of the 21st century across RCP scenarios. Meanwhile, the global mean surface ocean pH will drop 0.14–0.42 and the ocean surface mean concentration of carbonate will decrease 20%–51% across the RCP scenarios. The saturated state of sea water with respect to calcite carbonate minerals (Ω will decrease rapidly. During the pre-industrial period, 99% of the shallow-water coral reefs were surrounded by seawater with Ω > 3.5 and 87% of the deep-sea coral reefs were surrounded by seawater with aragonite supersaturation. Within the 21st century, except for the high mitigation scenario of RCP2.6, almost none shallow-water coral reefs will be surrounded by seawater with Ω > 3.5. Under the intensive emission scenario of RCP8.5, by the year 2100, the aragonite saturation horizon will rise to 308 m under the sea surface from 1138 m at the pre-industrial period, thus 73% of the cold-water coral reefs will be surrounded by seawater with aragonite undersaturation. By the year 2300, only 5% of the cold-water coral reefs will be surrounded by seawater with aragonite supersaturation.

  18. Benthic communities at two remote Pacific coral reefs: effects of reef habitat, depth, and wave energy gradients on spatial patterns.

    Science.gov (United States)

    Williams, Gareth J; Smith, Jennifer E; Conklin, Eric J; Gove, Jamison M; Sala, Enric; 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%), larger fleshy macroalgae were virtually absent at Kingman (wave energy, with hard coral cover decreasing and becoming more spatially clustered with increased wave energy, likely as a result of physical damage leading to patches of coral in localized shelter. In contrast, the cover of turf algae at Kingman was positively related to wave energy, reflecting their ability to rapidly colonize newly available space. No significant patterns with wave energy were observed on Palmyra's forereef, suggesting that a more detailed model is required to study biophysical coupling there. Kingman, Palmyra, and other remote oceanic reefs provide interesting case studies to explore biophysical influences on benthic ecology and dynamics.

  19. Future habitat suitability for coral reef ecosystems under global warming and ocean acidification.

    Science.gov (United States)

    Couce, Elena; Ridgwell, Andy; Hendy, Erica J

    2013-12-01

    Rising atmospheric CO2 concentrations are placing spatially divergent stresses on the world's tropical coral reefs through increasing ocean surface temperatures and ocean acidification. We show how these two stressors combine to alter the global habitat suitability for shallow coral reef ecosystems, using statistical Bioclimatic Envelope Models rather than basing projections on any a priori assumptions of physiological tolerances or fixed thresholds. We apply two different modeling approaches (Maximum Entropy and Boosted Regression Trees) with two levels of complexity (one a simplified and reduced environmental variable version of the other). Our models project a marked temperature-driven decline in habitat suitability for many of the most significant and bio-diverse tropical coral regions, particularly in the central Indo-Pacific. This is accompanied by a temperature-driven poleward range expansion of favorable conditions accelerating up to 40-70 km per decade by 2070. We find that ocean acidification is less influential for determining future habitat suitability than warming, and its deleterious effects are centered evenly in both hemispheres between 5° and 20° latitude. Contrary to expectations, the combined impact of ocean surface temperature rise and acidification leads to little, if any, degradation in future habitat suitability across much of the Atlantic and areas currently considered 'marginal' for tropical corals, such as the eastern Equatorial Pacific. These results are consistent with fossil evidence of range expansions during past warm periods. In addition, the simplified models are particularly sensitive to short-term temperature variations and their projections correlate well with reported locations of bleaching events. Our approach offers new insights into the relative impact of two global environmental pressures associated with rising atmospheric CO2 on potential future habitats, but greater understanding of past and current controls on coral

  20. 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.

  1. Coral Reef Ecosystems

    Science.gov (United States)

    Yap, Helen T.

    Coral reefs are geological structures of significant dimensions, constructed over millions of years by calcifying organisms. The present day reef-builders are hard corals belonging to the order Scleractinia, phylum Cnidaria. The greatest concentrations of coral reefs are in the tropics, with highest levels of biodiversity situated in reefs of the Indo-West Pacific region. These ecosystems have provided coastal protection and livelihood to human populations over the millennia. Human activities have caused destruction of these habitats, the intensity of which has increased alarmingly since the latter decades of the twentieth century. The severity of this impact is directly related to exponential growth rates of human populations especially in the coastal areas of the developing world. However, a more recently recognized phenomenon concerns disturbances brought about by the changing climate, manifested mainly as rising sea surface temperatures, and increasing acidification of ocean waters due to greater drawdown of higher concentrations of atmospheric carbon dioxide. Management efforts have so far not kept pace with the rates of degradation, so that the spatial extent of damaged reefs and the incidences of localized extinction of reef species are increasing year after year. The major management efforts to date consist of establishing marine protected areas and promoting the active restoration of coral habitats.

  2. KAHO_BenthicHabitats - Benthic habitat of the coral reef ecosystem within and adjacent to Kaloko-Honokohau National Historical Park (KAHO) on the Kona Coast of Hawaii.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A benthic habitat polygon coverage has been created of the coral reef ecosystem within and adjacent to Kaloko-Honokohau National Historical Park (KAHO) on the Kona...

  3. PUHE_BenthicHabitats - Benthic habitat of the coral reef ecosystem off the coast of Puukohola Heiau (PUHE) National Historic Site on the Kona Coast of Hawaii.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A benthic habitat polygon coverage has been created of the coral reef ecosystem off the coast of Pu'ukohola Heiau (PUHE) National Historic Site on the Kona Coast of...

  4. PUHO_BenthicHabitats - Benthic habitat of the coral reef ecosystem off the coast of Puuhonua O Honaunau (PUHO) National Historical Park on the Kona Coast of Hawaii.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A benthic habitat polygon coverage has been created of the coral reef ecosystem off the coast of Pu'uhonua O Honaunau (PUHO) National Historical Park on the Kona...

  5. PUHO_BenthicHabitats - Benthic habitat of the coral reef ecosystem off the coast of Puuhonua O Honaunau (PUHO) National Historical Park on the Kona Coast of Hawaii.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A benthic habitat polygon coverage has been created of the coral reef ecosystem off the coast of Pu'uhonua O Honaunau (PUHO) National Historical Park on the Kona...

  6. PUHE_BenthicHabitats - Benthic habitat of the coral reef ecosystem off the coast of Puukohola Heiau (PUHE) National Historic Site on the Kona Coast of Hawaii.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A benthic habitat polygon coverage has been created of the coral reef ecosystem off the coast of Pu'ukohola Heiau (PUHE) National Historic Site on the Kona Coast of...

  7. Avoiding conflicts and protecting coral reefs: Customary management benefits marine habitats and fish biomass

    KAUST Repository

    Campbell, Stuart J.

    2012-10-01

    Abstract One of the major goals of coral reef conservation is to determine the most effective means of managing marine resources in regions where economic conditions often limit the options available. For example, no-take fishing areas can be impractical in regions where people rely heavily on reef fish for food. In this study we test whether coral reef health differed among areas with varying management practices and socio-economic conditions on Pulau Weh in the Indonesian province of Aceh. Our results show that gear restrictions, in particular prohibiting the use of nets, were successful in minimizing habitat degradation and maintaining fish biomass despite ongoing access to the fishery. Reef fish biomass and hard-coral cover were two- to eight-fold higher at sites where fishing nets were prohibited. The guiding principle of the local customary management system, Panglima Laot, is to reduce conflict among community members over access to marine resources. Consequently, conservation benefits in Aceh have arisen from a customary system that lacks a specific environmental ethic or the means for strong resource-based management. Panglima Laot includes many of the features of successful institutions, such as clearly defined membership rights and the opportunity for resource users to be involved in making, enforcing and changing the rules. Such mechanisms to reduce conflict are the key to the success of marine resource management, particularly in settings that lack resources for enforcement. © 2012 Fauna & Flora International.

  8. Tropical coral reef habitat in a geoengineered, high-CO2 world

    Science.gov (United States)

    Couce, E.; Irvine, P. J.; Gregorie, L. J.; Ridgwell, A.; Hendy, E. J.

    2013-05-01

    Continued anthropogenic CO2 emissions are expected to impact tropical coral reefs by further raising sea surface temperatures (SST) and intensifying ocean acidification (OA). Although geoengineering by means of solar radiation management (SRM) may mitigate temperature increases, OA will persist, raising important questions regarding the impact of different stressor combinations. We apply statistical Bioclimatic Envelope Models to project changes in shallow water tropical coral reef habitat as a single niche (without resolving biodiversity or community composition) under various representative concentration pathway and SRM scenarios, until 2070. We predict substantial reductions in habitat suitability centered on the Indo-Pacific Warm Pool under net anthropogenic radiative forcing of ≥3.0 W/m2. The near-term dominant risk to coral reefs is increasing SSTs; below 3 W/m2 reasonably favorable conditions are maintained, even when achieved by SRM with persisting OA. "Optimal" mitigation occurs at 1.5 W/m2 because tropical SSTs overcool in a fully geoengineered (i.e., preindustrial global mean temperature) world.

  9. Density dependence drives habitat production and survivorship of Acropora cervicornis used for restoration on a Caribbean coral reef

    Directory of Open Access Journals (Sweden)

    Mark C Ladd

    2016-12-01

    Full Text Available AbstractCoral restoration is gaining traction as a viable strategy to help restore degraded reefs. While the nascent field of coral restoration has rapidly progressed in the past decade, significant knowledge gaps remain regarding the drivers of restoration success that may impede our ability to effectively restore coral reef communities. Here, we conducted a field experiment to investigate the influence of coral density on the growth, habitat production, and survival of corals outplanted for restoration. We used nursery-raised colonies of Acropora cervicornis to experimentally establish populations of corals with either 3, 6, 12, or 24 corals within 4m2 plots, generating a gradient of coral densities ranging from 0.75 corals m-2 to 12 corals m-2. After 13 months we found that density had a significant effect on the growth, habitat production, and survivorship of restored corals. We found that coral survivorship increased as colony density decreased. Importantly, the signal of density dependent effects was context dependent. Our data suggest that positive density dependent effects influenced habitat production at densities of 3 corals m-2, but further increases in density resulted in negative density dependent effects with decreasing growth and survivorship of corals. These findings highlight the importance of density dependence for coral restoration planning and demonstrate the need to evaluate the influence of density for other coral species used for restoration. Further work focused on the mechanisms causing density dependence such as increased herbivory, rapid disease transmission, or altered predation rates are important next steps to advance our ability to effectively restore coral reefs.

  10. Antioxidant responses to heat and light stress differ with habitat in a common reef coral

    Science.gov (United States)

    Hawkins, Thomas D.; Krueger, Thomas; Wilkinson, Shaun P.; Fisher, Paul L.; Davy, Simon K.

    2015-12-01

    Coral bleaching—the stress-induced collapse of the coral- Symbiodinium symbiosis—is a significant driver of worldwide coral reef degradation. Yet, not all corals are equally susceptible to bleaching, and we lack a clear understanding of the mechanisms underpinning their differential susceptibilities. Here, we focus on cellular redox regulation as a potential determinant of bleaching susceptibility in the reef coral Stylophora pistillata. Using slow heating (1 °C d-1) and altered irradiance, we induced bleaching in S. pistillata colonies sampled from two depths [5-8 m (shallow) and 15-18 m (deep)]. There was significant depth-dependent variability in the timing and extent of bleaching (loss of symbiont cells), as well as in host enzymatic antioxidant activity [specifically, superoxide dismutase and catalase (CAT)]. However, among the coral fragments that bleached, most did so without displaying any evidence of a host enzymatic antioxidant response. For example, both deep and shallow corals suffered significant symbiont loss at elevated temperature, but only deep colonies exposed to high temperature and high light displayed any up-regulation of host antioxidant enzyme activity (CAT). Surprisingly, this preceded the equivalent antioxidant responses of the symbiont, which raises questions about the source(s) of hydrogen peroxide in the symbiosis. Overall, changes in enzymatic antioxidant activity in the symbionts were driven primarily by irradiance rather than temperature, and responses were similar across depth groups. Taken together, our results suggest that in the absence of light stress, heating of 1 °C d-1 to 4 °C above ambient is not sufficient to induce a substantial oxidative challenge in S. pistillata. We provide some of the first evidence that regulation of coral enzymatic antioxidants can vary significantly depending on habitat, and, in terms of determining bleaching susceptibility, our results suggest a significant role for the host's differential

  11. Seasonal and ontogenetic patterns of habitat use in coral reef fish juveniles

    Science.gov (United States)

    Mellin, C.; Kulbicki, M.; Ponton, D.

    2007-12-01

    We investigated the diversity of patterns of habitat use by juveniles of coral reef fishes according to seasons and at two spatial scales (10-100 m and 1-10 km). We conducted underwater visual censuses in New Caledonia's Lagoon between 1986 and 2001. Co-inertia analyses highlighted the importance of mid-shelf habitats at large spatial scale (1-10 km) and of sandy and vegetated habitats at small spatial scale (10-100 m) for most juveniles. Among all juvenile species, 53% used different habitats across seasons (e.g. Lutjanus fulviflamma and Siganus argenteus) and 39% used different habitats as they grow (e.g. Lethrinus atkinsoni and Scarus ghobban). During their ontogeny, at large and small scales, respectively, 21% and 33% of the species studied showed an increase in the number of habitats used (e.g. L. fulviflamma, L. atkinsoni), 10% and 3% showed a decrease in the number of habitats used (e.g. Amphiprion melanopus, Siganus fuscescens), 23% and 3% showed a drastic change of habitat used (e.g. S. ghobban, Scarus sp.) whereas 46% and 61% showed no change of habitat used (e.g. Lethrinus genivittatus, Ctenochaetus striatus). Changes in habitat use at both small and large spatial scales occurred during the ontogeny of several species (e.g. S. ghobban, Scarus sp.). Results pointed out the different spatial and temporal scales of juvenile habitat use to account for in conservation decisions regarding both assemblage and species-specific levels.

  12. Global ecological success of Thalassoma fishes in extreme coral reef habitats

    KAUST Repository

    Fulton, Christopher J.

    2016-12-20

    Phenotypic adaptations can allow organisms to relax abiotic selection and facilitate their ecological success in challenging habitats, yet we have relatively little data for the prevalence of this phenomenon at macroecological scales. Using data on the relative abundance of coral reef wrasses and parrotfishes (f. Labridae) spread across three ocean basins and the Red Sea, we reveal the consistent global dominance of extreme wave-swept habitats by fishes in the genus Thalassoma, with abundances up to 15 times higher than any other labrid. A key locomotor modification-a winged pectoral fin that facilitates efficient underwater flight in high-flow environments-is likely to have underpinned this global success, as numerical dominance by Thalassoma was contingent upon the presence of high-intensity wave energy. The ecological success of the most abundant species also varied with species richness and the presence of congeneric competitors. While several fish taxa have independently evolved winged pectoral fins, Thalassoma appears to have combined efficient high-speed swimming (to relax abiotic selection) with trophic versatility (to maximize exploitation of rich resources) to exploit and dominate extreme coral reef habitats around the world.

  13. Coral reefs - Specialized ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    This paper discusses briefly some aspects that characterize and differentiate coral reef ecosystems from other tropical marine ecosystems. A brief account on the resources that are extractable from coral reefs, their susceptibility to natural...

  14. 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.

  15. Diving behavior of the reef manta ray links coral reefs with adjacent deep pelagic habitats.

    Science.gov (United States)

    Braun, Camrin D; Skomal, Gregory B; Thorrold, Simon R; Berumen, Michael L

    2014-01-01

    Recent successful efforts to increase protection for manta rays has highlighted the lack of basic ecological information, including vertical and horizontal movement patterns, available for these species. We deployed pop-up satellite archival transmitting tags on nine reef manta rays, Manta alfredi, to determine diving behaviors and vertical habitat use. Transmitted and archived data were obtained from seven tagged mantas over deployment periods of 102-188 days, including three recovered tags containing 2.6 million depth, temperature, and light level data points collected every 10 or 15 seconds. Mantas frequented the upper 10 m during daylight hours and tended to occupy deeper water throughout the night. Six of the seven individuals performed a cumulative 76 deep dives (>150 m) with one individual reaching 432 m, extending the known depth range of this coastal, reef-oriented species and confirming its role as an ecological link between epipelagic and mesopelagic habitats. Mean vertical velocities calculated from high-resolution dive data (62 dives >150 m) from three individuals suggested that mantas may use gliding behavior during travel and that this behavior may prove more efficient than continuous horizontal swimming. The behaviors in this study indicate manta rays provide a previously unknown link between the epi- and mesopelagic layers of an extremely oligotrophic marine environment and provide evidence of a third marine species that utilizes gliding to maximize movement efficiency.

  16. Diving behavior of the reef manta ray links coral reefs with adjacent deep pelagic habitats.

    Directory of Open Access Journals (Sweden)

    Camrin D Braun

    Full Text Available Recent successful efforts to increase protection for manta rays has highlighted the lack of basic ecological information, including vertical and horizontal movement patterns, available for these species. We deployed pop-up satellite archival transmitting tags on nine reef manta rays, Manta alfredi, to determine diving behaviors and vertical habitat use. Transmitted and archived data were obtained from seven tagged mantas over deployment periods of 102-188 days, including three recovered tags containing 2.6 million depth, temperature, and light level data points collected every 10 or 15 seconds. Mantas frequented the upper 10 m during daylight hours and tended to occupy deeper water throughout the night. Six of the seven individuals performed a cumulative 76 deep dives (>150 m with one individual reaching 432 m, extending the known depth range of this coastal, reef-oriented species and confirming its role as an ecological link between epipelagic and mesopelagic habitats. Mean vertical velocities calculated from high-resolution dive data (62 dives >150 m from three individuals suggested that mantas may use gliding behavior during travel and that this behavior may prove more efficient than continuous horizontal swimming. The behaviors in this study indicate manta rays provide a previously unknown link between the epi- and mesopelagic layers of an extremely oligotrophic marine environment and provide evidence of a third marine species that utilizes gliding to maximize movement efficiency.

  17. Diving behavior of the reef manta ray links coral reefs with adjacent deep pelagic habitats

    KAUST Repository

    Braun, Camrin D.

    2014-02-06

    Recent successful efforts to increase protection for manta rays has highlighted the lack of basic ecological information, including vertical and horizontal movement patterns, available for these species. We deployed pop-up satellite archival transmitting tags on nine reef manta rays, Manta alfredi, to determine diving behaviors and vertical habitat use. Transmitted and archived data were obtained from seven tagged mantas over deployment periods of 102-188 days, including three recovered tags containing 2.6 million depth, temperature, and light level data points collected every 10 or 15 seconds. Mantas frequented the upper 10 m during daylight hours and tended to occupy deeper water throughout the night. Six of the seven individuals performed a cumulative 76 deep dives (>150 m) with one individual reaching 432 m, extending the known depth range of this coastal, reef-oriented species and confirming its role as an ecological link between epipelagic and mesopelagic habitats. Mean vertical velocities calculated from high-resolution dive data (62 dives >150 m) from three individuals suggested that mantas may use gliding behavior during travel and that this behavior may prove more efficient than continuous horizontal swimming. The behaviors in this study indicate manta rays provide a previously unknown link between the epi- and mesopelagic layers of an extremely oligotrophic marine environment and provide evidence of a third marine species that utilizes gliding to maximize movement efficiency. © 2014 Braun et al.

  18. Biology of corals and coral reefs

    Digital Repository Service at National Institute of Oceanography (India)

    Rajkumar, R.; Parulekar, A.H.

    This chapter deals with biology of corals, coral reefs (in general) and coral reefs of the Indian Ocean. Biology of corals is lucidly dealt with, beginning from the clarification on hermatypic and ahermatypic forms. A complete account...

  19. Estimating Surface Area of Sponges and Marine Gorgonians as Indicators of Habitat Availability on Caribbean Coral Reefs

    Science.gov (United States)

    Surface area and topographical complexity are fundamental attributes of shallow tropical coral reefs and can be used to estimate habitat for fish and invertebrates. This study presents empirical methods for estimating surface area provided by sponges and gorgonians in the Central...

  20. Estimating Surface Area of Sponges and Marine Gorgonians as Indicators of Habitat Availability on Caribbean Coral Reefs

    Science.gov (United States)

    Surface area and topographical complexity are fundamental attributes of shallow tropical coral reefs and can be used to estimate habitat for fish and invertebrates. This study presents empirical methods for estimating surface area provided by sponges and gorgonians in the Central...

  1. Extent of mangrove nursery habitats determines the geographic distribution of a coral reef fish in a South-Pacific archipelago.

    Directory of Open Access Journals (Sweden)

    Christelle Paillon

    Full Text Available Understanding the drivers of species' geographic distribution has fundamental implications for the management of biodiversity. For coral reef fishes, mangroves have long been recognized as important nursery habitats sustaining biodiversity in the Western Atlantic but there is still debate about their role in the Indo-Pacific. Here, we combined LA-ICP-MS otolith microchemistry, underwater visual censuses (UVC and mangrove cartography to estimate the importance of mangroves for the Indo-Pacific coral reef fish Lutjanus fulviflamma in the archipelago of New Caledonia. Otolith elemental compositions allowed high discrimination of mangroves and reefs with 83.8% and 98.7% correct classification, respectively. Reefs were characterized by higher concentrations of Rb and Sr and mangroves by higher concentrations of Ba, Cr, Mn and Sn. All adult L. fulviflamma collected on reefs presented a mangrove signature during their juvenile stage with 85% inhabiting mangrove for their entire juvenile life (about 1 year. The analysis of 2942 UVC revealed that the species was absent from isolated islands of the New Caledonian archipelago where mangroves were absent. Furthermore, strong positive correlations existed between the abundance of L. fulviflamma and the area of mangrove (r = 0.84 for occurrence, 0.93 for density and 0.89 for biomass. These results indicate that mangrove forest is an obligatory juvenile habitat for L. fulviflamma in New Caledonia and emphasize the potential importance of mangroves for Indo-Pacific coral reef fishes.

  2. Coral reef habitats mapping of Spermonde Archipelago using remote sensing compared with in situ survey of fish abundance

    Science.gov (United States)

    Sawayama, Shuhei; Komatsu, Teruhisa; Nurdin, Nurjannah

    2012-10-01

    Coral reefs worldwide are now facing so great threat due to various impacts that their monitoring is urgently required for conservation and management. To understand status of coral reef ecosystem and find out indicator fish species for health of ecosystem, mapping seabed habitats with remote sensing and in situ visual survey of fish assemblage by snorkeling were conducted in coral reefs in Spermonde Archipelago, Indonesia. ALOS AVNIR-2 multi-band imagery on 14 October 2010 was analyzed to map four habitats: live coral, dead coral, seagrass and sand-rubble. Groundtruth data were obtained using towed video camera and sidescan sonar in May and June 2011. Depth-Invariant indices (DI-indices) based on ratios of radiance values between bands were applied as a water column correction. Overall classification accuracy in Tau-coefficient of mapping with the DI-indices (0.66) didn't differ significantly (p<0.05) from that with the radiance values (0.63). Concerning visual fish survey, 12 fish groups were identified and numbers of individuals belonging to each group were counted along a transect of approximately 100m at 18 sites. We calculated Spearman's rank correlation between abundance (Ind. /100m) of every fish group along a transect and the ratio of each habitat area mapped with DI-indices inside the circle with 50m-diameter which includes the fish transect. We detected significant correlations between abundance of five fish groups and specific habitats, especially butterflyfish and live coral. This result corresponds to the past reports that butterflyfish was a good indicator of healthy corals, suggesting meaningfulness of studying relationships between fish abundance and spatial distribution of habitats in larger scale.

  3. Coral reef fish assemblages of coralline and granitic habitats of Curieuse Marine National Park

    OpenAIRE

    Pittman, S.J.

    1997-01-01

    Curieuse Marine National Park encompasses a diverse range of shallow water marine and brackish habitats including coralline fringing reefs, granitic boulder reefs, deep patch reefs, algal flats, seagrass meadows, intertidal rocky shore, sandy beach and mangrove habitat. Many of these shallow water habitats support an abundance of varied marine life, which in turn supports a burgeoning interest from tourist divers and snorkellers. Curieuse Marine National Park includes Curieuse Island and t...

  4. Test of the Capability of Laser Line Scan Technology to Support Benthic Habitat Mapping in Coral Reef Ecosystems, Maui Island, November 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The utility of Laser Line Scan (LLS) Technology for optical validation of benthic habitat map data from coral reef ecosystems was tested with a deployment of a...

  5. Use of habitats as surrogates of biodiversity for efficient coral reef conservation planning in Pacific Ocean islands.

    Science.gov (United States)

    Dalleau, Mayeul; Andréfouët, Serge; Wabnitz, Colette C C; Payri, Claude; Wantiez, Laurent; Pichon, Michel; Friedman, Kim; Vigliola, Laurent; Benzoni, Francesca

    2010-04-01

    Marine protected areas (MPAs) have been highlighted as a means toward effective conservation of coral reefs. New strategies are required to more effectively select MPA locations and increase the pace of their implementation. Many criteria exist to design MPA networks, but generally, it is recommended that networks conserve a diversity of species selected for, among other attributes, their representativeness, rarity, or endemicity. Because knowledge of species' spatial distribution remains scarce, efficient surrogates are urgently needed. We used five different levels of habitat maps and six spatial scales of analysis to identify under which circumstances habitat data used to design MPA networks for Wallis Island provided better representation of species than random choice alone. Protected-area site selections were derived from a rarity-complementarity algorithm. Habitat surrogacy was tested for commercial fish species, all fish species, commercially harvested invertebrates, corals, and algae species. Efficiency of habitat surrogacy varied by species group, type of habitat map, and spatial scale of analysis. Maps with the highest habitat thematic complexity provided better surrogates than simpler maps and were more robust to changes in spatial scales. Surrogates were most efficient for commercial fishes, corals, and algae but not for commercial invertebrates. Conversely, other measurements of species-habitat associations, such as richness congruence and composition similarities provided weak results. We provide, in part, a habitat-mapping methodology for designation of MPAs for Pacific Ocean islands that are characterized by habitat zonations similar to Wallis. Given the increasing availability and affordability of space-borne imagery to map habitats, our approach could appreciably facilitate and improve current approaches to coral reef conservation and enhance MPA implementation.

  6. Coral Transplantation and Restocking to Accelerate the Recovery of Coral Reef Habitats and Fisheries Resources Within No-Take Marine Protected Areas: Hands-On Approaches to Support Community-Based Coral Reef Management

    OpenAIRE

    Bowden-Kerby, A.

    2003-01-01

    Of the planet’s 600,000 km2 of coral reefs (Jameson et al., 1995), roughly 70-80% are located in developing countries. Many of these reefs are owned or controlled by indigenous fishing communities rather than national or state governments. These rural fishing communities are a primary force of destruction to coral reefs on a global scale (Wilkinson, 1998), therefore their involvement in the management and conservation of coral reefs will be an essential part of reversing coral ...

  7. Human, oceanographic and habitat drivers of central and western Pacific coral reef fish assemblages.

    Directory of Open Access Journals (Sweden)

    Ivor D Williams

    Full Text Available Coral reefs around US- and US-affiliated Pacific islands and atolls span wide oceanographic gradients and levels of human impact. Here we examine the relative influence of these factors on coral reef fish biomass, using data from a consistent large-scale ecosystem monitoring program conducted by scientific divers over the course of >2,000 hours of underwater observation at 1,934 sites, across ~40 islands and atolls. Consistent with previous smaller-scale studies, our results show sharp declines in reef fish biomass at relatively low human population density, followed by more gradual declines as human population density increased further. Adjusting for other factors, the highest levels of oceanic productivity among our study locations were associated with more than double the biomass of reef fishes (including ~4 times the biomass of planktivores and piscivores compared to islands with lowest oceanic productivity. Our results emphasize that coral reef areas do not all have equal ability to sustain large reef fish stocks, and that what is natural varies significantly amongst locations. Comparisons of biomass estimates derived from visual surveys with predicted biomass in the absence of humans indicated that total reef fish biomass was depleted by 61% to 69% at populated islands in the Mariana Archipelago; by 20% to 78% in the Main Hawaiian islands; and by 21% to 56% in American Samoa.

  8. Adaptive divergence in a scleractinian coral: physiological adaptation of Seriatopora hystrix to shallow and deep reef habitats

    Directory of Open Access Journals (Sweden)

    van Oppen Madeleine JH

    2011-10-01

    Full Text Available Abstract Background Divergent natural selection across environmental gradients has been acknowledged as a major driver of population and species divergence, however its role in the diversification of scleractinian corals remains poorly understood. Recently, it was demonstrated that the brooding coral Seriatopora hystrix and its algal endosymbionts (Symbiodinium are genetically partitioned across reef environments (0-30 m on the far northern Great Barrier Reef. Here, we explore the potential mechanisms underlying this differentiation and assess the stability of host-symbiont associations through a reciprocal transplantation experiment across habitats ('Back Reef', 'Upper Slope' and 'Deep Slope', in combination with molecular (mtDNA and ITS2-DGGE and photo-physiological analyses (respirometry and HPLC. Results The highest survival rates were observed for native transplants (measured 14 months after transplantation, indicating differential selective pressures between habitats. Host-symbiont assemblages remained stable during the experimental duration, demonstrating that the ability to "shuffle" or "switch" symbionts is restricted in S. hystrix. Photo-physiological differences were observed between transplants originating from the shallow and deep habitats, with indirect evidence of an increased heterotrophic capacity in native deep-water transplants (from the 'Deep Slope' habitat. Similar photo-acclimatisation potential was observed between transplants originating from the two shallow habitats ('Back Reef' and 'Upper Slope', highlighting that their genetic segregation over depth may be due to other, non-photo-physiological traits under selection. Conclusions This study confirms that the observed habitat partitioning of S. hystrix (and associated Symbiodinium is reflective of adaptive divergence along a depth gradient. Gene flow appears to be reduced due to divergent selection, highlighting the potential role of ecological mechanisms, in addition to

  9. Spectral Diversity and Regulation of Coral Fluorescence in a Mesophotic Reef Habitat in the Red Sea

    Science.gov (United States)

    Eyal, Gal; Wiedenmann, Jörg; Grinblat, Mila; D’Angelo, Cecilia; Kramarsky-Winter, Esti; Treibitz, Tali; Ben-Zvi, Or; Shaked, Yonathan; Smith, Tyler B.; Harii, Saki; Denis, Vianney; Noyes, Tim; Tamir, Raz; Loya, Yossi

    2015-01-01

    The phenomenon of coral fluorescence in mesophotic reefs, although well described for shallow waters, remains largely unstudied. We found that representatives of many scleractinian species are brightly fluorescent at depths of 50–60 m at the Interuniversity Institute for Marine Sciences (IUI) reef in Eilat, Israel. Some of these fluorescent species have distribution maxima at mesophotic depths (40–100 m). Several individuals from these depths displayed yellow or orange-red fluorescence, the latter being essentially absent in corals from the shallowest parts of this reef. We demonstrate experimentally that in some cases the production of fluorescent pigments is independent of the exposure to light; while in others, the fluorescence signature is altered or lost when the animals are kept in darkness. Furthermore, we show that green-to-red photoconversion of fluorescent pigments mediated by short-wavelength light can occur also at depths where ultraviolet wavelengths are absent from the underwater light field. Intraspecific colour polymorphisms regarding the colour of the tissue fluorescence, common among shallow water corals, were also observed for mesophotic species. Our results suggest that fluorescent pigments in mesophotic reefs fulfil a distinct biological function and offer promising application potential for coral-reef monitoring and biomedical imaging. PMID:26107282

  10. Using novel acoustic and visual mapping tools to predict the small-scale spatial distribution of live biogenic reef framework in cold-water coral habitats

    NARCIS (Netherlands)

    De Clippele, L. H.; Gafeira, J.; Robert, K.; Hennige, S.; Lavaleye, M.S.; Duineveld, G.C.A.; Huvenne, V.A.I.; Roberts, J.M.

    2017-01-01

    Cold-water corals form substantial biogenic habitats on continental shelves and in deep-sea areas with topographic highs, such as banks and seamounts. In the Atlantic, many reef and mound complexes are engineered by Lophelia pertusa, the dominant framework-forming coral. In this study, a variety of

  11. No habitat correlation of zooxanthellae in the coral genus Madracis on a Curacao reef

    NARCIS (Netherlands)

    Diekmann, O.E; Bak, R.P M; Tonk, L; Stam, W.T.; Olsen, J.L.

    2002-01-01

    Symbiotic dinoflagellates belonging to the genus Symbiodinium (zooxanthellae) play an important role in ecological specialization and physiological adaptation in corals, We examined the diversity and depth distribution of zooxanthellae in 5 morphospecies of Madracis at the Buoy I study-reef on

  12. No habitat correlation of zooxanthellae in the coral genus Madracis on a Curacao reef

    NARCIS (Netherlands)

    Diekmann, O.E; Bak, R.P M; Tonk, L; Stam, W.T.; Olsen, J.L.

    2002-01-01

    Symbiotic dinoflagellates belonging to the genus Symbiodinium (zooxanthellae) play an important role in ecological specialization and physiological adaptation in corals, We examined the diversity and depth distribution of zooxanthellae in 5 morphospecies of Madracis at the Buoy I study-reef on Curac

  13. 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…

  14. 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…

  15. Using novel acoustic and visual mapping tools to predict the small-scale spatial distribution of live biogenic reef framework in cold-water coral habitats

    Science.gov (United States)

    De Clippele, L. H.; Gafeira, J.; Robert, K.; Hennige, S.; Lavaleye, M. S.; Duineveld, G. C. A.; Huvenne, V. A. I.; Roberts, J. M.

    2017-03-01

    Cold-water corals form substantial biogenic habitats on continental shelves and in deep-sea areas with topographic highs, such as banks and seamounts. In the Atlantic, many reef and mound complexes are engineered by Lophelia pertusa, the dominant framework-forming coral. In this study, a variety of mapping approaches were used at a range of scales to map the distribution of both cold-water coral habitats and individual coral colonies at the Mingulay Reef Complex (west Scotland). The new ArcGIS-based British Geological Survey (BGS) seabed mapping toolbox semi-automatically delineated over 500 Lophelia reef `mini-mounds' from bathymetry data with 2-m resolution. The morphometric and acoustic characteristics of the mini-mounds were also automatically quantified and captured using this toolbox. Coral presence data were derived from high-definition remotely operated vehicle (ROV) records and high-resolution microbathymetry collected by a ROV-mounted multibeam echosounder. With a resolution of 0.35 × 0.35 m, the microbathymetry covers 0.6 km2 in the centre of the study area and allowed identification of individual live coral colonies in acoustic data for the first time. Maximum water depth, maximum rugosity, mean rugosity, bathymetric positioning index and maximum current speed were identified as the environmental variables that contributed most to the prediction of live coral presence. These variables were used to create a predictive map of the likelihood of presence of live cold-water coral colonies in the area of the Mingulay Reef Complex covered by the 2-m resolution data set. Predictive maps of live corals across the reef will be especially valuable for future long-term monitoring surveys, including those needed to understand the impacts of global climate change. This is the first study using the newly developed BGS seabed mapping toolbox and an ROV-based microbathymetric grid to explore the environmental variables that control coral growth on cold-water coral

  16. Coral reef ecosystem

    Digital Repository Service at National Institute of Oceanography (India)

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

    communication). Fossil reefs, drowned as a result of the Holocene sea level rise, occur at 92, 85, 75 and 55 m depth along .. ~ !! ":2 0. ~ Figure 3.1 Graphical Representation of the SO-Box Model of a Caribbean Coral Reef Key: 1. Benthic producers. 2. Detritus... explain the low species diversity and the absence of branching corals in the intertidal regions. H.aised fossil reefs, proba bly as a result of local upheavals, arc found in Minicoy island (Gardiner 1903), in Ramanalhapuram district in Tamil Nadu...

  17. Small-scale habitat structure modulates the effects of no-take marine reserves for coral reef macroinvertebrates.

    Directory of Open Access Journals (Sweden)

    Pascal Dumas

    Full Text Available No-take marine reserves are one of the oldest and most versatile tools used across the Pacific for the conservation of reef resources, in particular for invertebrates traditionally targeted by local fishers. Assessing their actual efficiency is still a challenge in complex ecosystems such as coral reefs, where reserve effects are likely to be obscured by high levels of environmental variability. The goal of this study was to investigate the potential interference of small-scale habitat structure on the efficiency of reserves. The spatial distribution of widely harvested macroinvertebrates was surveyed in a large set of protected vs. unprotected stations from eleven reefs located in New Caledonia. Abundance, density and individual size data were collected along random, small-scale (20×1 m transects. Fine habitat typology was derived with a quantitative photographic method using 17 local habitat variables. Marine reserves substantially augmented the local density, size structure and biomass of the target species. Density of Trochus niloticus and Tridacna maxima doubled globally inside the reserve network; average size was greater by 10 to 20% for T. niloticus. We demonstrated that the apparent success of protection could be obscured by marked variations in population structure occurring over short distances, resulting from small-scale heterogeneity in the reef habitat. The efficiency of reserves appeared to be modulated by the availability of suitable habitats at the decimetric scale ("microhabitats" for the considered sessile/low-mobile macroinvertebrate species. Incorporating microhabitat distribution could significantly enhance the efficiency of habitat surrogacy, a valuable approach in the case of conservation targets focusing on endangered or emblematic macroinvertebrate or relatively sedentary fish species.

  18. Small-Scale Habitat Structure Modulates the Effects of No-Take Marine Reserves for Coral Reef Macroinvertebrates

    Science.gov (United States)

    Dumas, Pascal; Jimenez, Haizea; Peignon, Christophe; Wantiez, Laurent; Adjeroud, Mehdi

    2013-01-01

    No-take marine reserves are one of the oldest and most versatile tools used across the Pacific for the conservation of reef resources, in particular for invertebrates traditionally targeted by local fishers. Assessing their actual efficiency is still a challenge in complex ecosystems such as coral reefs, where reserve effects are likely to be obscured by high levels of environmental variability. The goal of this study was to investigate the potential interference of small-scale habitat structure on the efficiency of reserves. The spatial distribution of widely harvested macroinvertebrates was surveyed in a large set of protected vs. unprotected stations from eleven reefs located in New Caledonia. Abundance, density and individual size data were collected along random, small-scale (20×1 m) transects. Fine habitat typology was derived with a quantitative photographic method using 17 local habitat variables. Marine reserves substantially augmented the local density, size structure and biomass of the target species. Density of Trochus niloticus and Tridacna maxima doubled globally inside the reserve network; average size was greater by 10 to 20% for T. niloticus. We demonstrated that the apparent success of protection could be obscured by marked variations in population structure occurring over short distances, resulting from small-scale heterogeneity in the reef habitat. The efficiency of reserves appeared to be modulated by the availability of suitable habitats at the decimetric scale (“microhabitats”) for the considered sessile/low-mobile macroinvertebrate species. Incorporating microhabitat distribution could significantly enhance the efficiency of habitat surrogacy, a valuable approach in the case of conservation targets focusing on endangered or emblematic macroinvertebrate or relatively sedentary fish species PMID:23554965

  19. Small-scale habitat structure modulates the effects of no-take marine reserves for coral reef macroinvertebrates.

    Science.gov (United States)

    Dumas, Pascal; Jimenez, Haizea; Peignon, Christophe; Wantiez, Laurent; Adjeroud, Mehdi

    2013-01-01

    No-take marine reserves are one of the oldest and most versatile tools used across the Pacific for the conservation of reef resources, in particular for invertebrates traditionally targeted by local fishers. Assessing their actual efficiency is still a challenge in complex ecosystems such as coral reefs, where reserve effects are likely to be obscured by high levels of environmental variability. The goal of this study was to investigate the potential interference of small-scale habitat structure on the efficiency of reserves. The spatial distribution of widely harvested macroinvertebrates was surveyed in a large set of protected vs. unprotected stations from eleven reefs located in New Caledonia. Abundance, density and individual size data were collected along random, small-scale (20×1 m) transects. Fine habitat typology was derived with a quantitative photographic method using 17 local habitat variables. Marine reserves substantially augmented the local density, size structure and biomass of the target species. Density of Trochus niloticus and Tridacna maxima doubled globally inside the reserve network; average size was greater by 10 to 20% for T. niloticus. We demonstrated that the apparent success of protection could be obscured by marked variations in population structure occurring over short distances, resulting from small-scale heterogeneity in the reef habitat. The efficiency of reserves appeared to be modulated by the availability of suitable habitats at the decimetric scale ("microhabitats") for the considered sessile/low-mobile macroinvertebrate species. Incorporating microhabitat distribution could significantly enhance the efficiency of habitat surrogacy, a valuable approach in the case of conservation targets focusing on endangered or emblematic macroinvertebrate or relatively sedentary fish species.

  20. Coral reefs in crisis.

    Science.gov (United States)

    Hinrichsen, D

    1997-01-01

    This article reports on the crisis facing reefs throughout the world and the struggle to save them. Coral reefs, one of the biological wonders of the world, are among the largest and oldest living communities of plants and animals on earth, having been evolved between 200 and 450 million years ago. Located mostly in the Pacific region, most established coral reefs are now dead and only the upper layer is covered by a thin changeable skin of living coral. Reefs, over the years, have been the main source of animal protein for over 1 billion people in Asia. Countries near the coastlines, which relied on the seas, have resorted to dynamite fishing, poisoning and other illegal and dangerous techniques. Overpopulation and pollution has caused the deteriorating conditions of the 600,000 sq. km of coral reefs worldwide. Despite these conditions, the government has ignored this problem as they struggle to develop their economies at the expense of common resources. In addition, this article narrates the efforts that are exerted by governments in promoting coral reef protection and management of these coastal resources, setting the Apo Island in the Philippines as an example of good management and sustainability.

  1. 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

    ..., 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 has... Coral Reef Research Foundation (CRRF, http://www.coralreefresearchfoundation.org/ ). Samples would be...

  2. 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

    ..., 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 South... Cancer Institute ( http://www.cancer.gov/ ) and the Coral Reef Research Foundation (CRRF, http://www...

  3. 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

  4. Spatial analyses of benthic habitats to define coral reef ecosystem regions and potential biogeographic boundaries along a latitudinal gradient.

    Directory of Open Access Journals (Sweden)

    Brian K Walker

    Full Text Available Marine organism diversity typically attenuates latitudinally from tropical to colder climate regimes. Since the distribution of many marine species relates to certain habitats and depth regimes, mapping data provide valuable information in the absence of detailed ecological data that can be used to identify and spatially quantify smaller scale (10 s km coral reef ecosystem regions and potential physical biogeographic barriers. This study focused on the southeast Florida coast due to a recognized, but understudied, tropical to subtropical biogeographic gradient. GIS spatial analyses were conducted on recent, accurate, shallow-water (0-30 m benthic habitat maps to identify and quantify specific regions along the coast that were statistically distinct in the number and amount of major benthic habitat types. Habitat type and width were measured for 209 evenly-spaced cross-shelf transects. Evaluation of groupings from a cluster analysis at 75% similarity yielded five distinct regions. The number of benthic habitats and their area, width, distance from shore, distance from each other, and LIDAR depths were calculated in GIS and examined to determine regional statistical differences. The number of benthic habitats decreased with increasing latitude from 9 in the south to 4 in the north and many of the habitat metrics statistically differed between regions. Three potential biogeographic barriers were found at the Boca, Hillsboro, and Biscayne boundaries, where specific shallow-water habitats were absent further north; Middle Reef, Inner Reef, and oceanic seagrass beds respectively. The Bahamas Fault Zone boundary was also noted where changes in coastal morphologies occurred that could relate to subtle ecological changes. The analyses defined regions on a smaller scale more appropriate to regional management decisions, hence strengthening marine conservation planning with an objective, scientific foundation for decision making. They provide a framework

  5. Coral larvae move toward reef sounds.

    Science.gov (United States)

    Vermeij, Mark J A; Marhaver, Kristen L; Huijbers, Chantal M; Nagelkerken, Ivan; Simpson, Stephen D

    2010-05-14

    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 (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.

  6. Maintenance of fish diversity on disturbed coral reefs

    Science.gov (United States)

    Wilson, S. K.; Dolman, A. M.; Cheal, A. J.; Emslie, M. J.; Pratchett, M. S.; Sweatman, H. P. A.

    2009-03-01

    Habitat perturbations play a major role in shaping community structure; however, the elements of disturbance-related habitat change that affect diversity are not always apparent. This study examined the effects of habitat disturbances on species richness of coral reef fish assemblages using annual surveys of habitat and 210 fish species from 10 reefs on the Great Barrier Reef (GBR). Over a period of 11 years, major disturbances, including localised outbreaks of crown-of-thorns sea star ( Acanthaster planci), severe storms or coral bleaching, resulted in coral decline of 46-96% in all the 10 reefs. Despite declines in coral cover, structural complexity of the reef framework was retained on five and species richness of coral reef fishes maintained on nine of the disturbed reefs. Extensive loss of coral resulted in localised declines of highly specialised coral-dependent species, but this loss of diversity was more than compensated for by increases in the number of species that feed on the epilithic algal matrix (EAM). A unimodal relationship between areal coral cover and species richness indicated species richness was greatest at approximately 20% coral cover declining by 3-4 species (6-8% of average richness) at higher and lower coral cover. Results revealed that declines in coral cover on reefs may have limited short-term impact on the diversity of coral reef fishes, though there may be fundamental changes in the community structure of fishes.

  7. Coral reefs at risk

    Science.gov (United States)

    Showstack, Randy

    Eighty-eight percent of Southeast Asia's reefs are threatened by overfishing, destructive fishing, and sedimentation and pollution from inland activities, according to a new report by 35 regional scientists published by the World Resources Institute.Nearly 100,000 square kilometers of coral reefs—34% of the world's total—are located in Southeast Asia.

  8. Coral Reef Biological Criteria

    Science.gov (United States)

    Coral reefs worldwide are experiencing decline from a variety of stressors. Some important stressors are land-based sources of pollution and human activities in the coastal zone. However, few tools are available to offset the impact of these stressors. The Clean Water Act (CWA...

  9. Designing Climate-Resilient Marine Protected Area Networks by Combining Remotely Sensed Coral Reef Habitat with Coastal Multi-Use Maps

    Directory of Open Access Journals (Sweden)

    Joseph M. Maina

    2015-12-01

    Full Text Available Decision making for the conservation and management of coral reef biodiversity requires an understanding of spatial variability and distribution of reef habitat types. Despite the existence of very high-resolution remote sensing technology for nearly two decades, comprehensive assessment of coral reef habitats at national to regional spatial scales and at very high spatial resolution is still scarce. Here, we develop benthic habitat maps at a sub-national scale by analyzing large multispectral QuickBird imagery dataset covering ~686 km2 of the main shallow coral fringing reef along the southern border with Tanzania (4.68°S, 39.18°E to the reef end at Malindi, Kenya (3.2°S, 40.1°E. Mapping was conducted with a user approach constrained by ground-truth data, with detailed transect lines from the shore to the fore reef. First, maps were used to evaluate the present management system’s effectiveness at representing habitat diversity. Then, we developed three spatial prioritization scenarios based on differing objectives: (i minimize lost fishing opportunity; (ii redistribute fisheries away from currently overfished reefs; and (iii minimize resource use conflicts. We further constrained the priority area in each prioritization selection scenario based on optionally protecting the least or the most climate exposed locations using a model of exposure to climate stress. We discovered that spatial priorities were very different based on the different objectives and on whether the aim was to protect the least or most climate-exposed habitats. Our analyses provide a spatially explicit foundation for large-scale conservation and management strategies that can account for ecosystem service benefits.

  10. 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.

  11. 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.

  12. Bomb-cratered coral reefs in Puerto Rico, the untold story about a novel habitat: from reef destruction to community-based ecological rehabilitation

    Directory of Open Access Journals (Sweden)

    Edwin A. Hernández-Delgado

    2014-09-01

    Full Text Available Ecological impacts of military bombing activities in Puerto Rico have often been described as minimal, with recurrent allegations of confounding effects by hurricanes, coral diseases and local anthropogenic stressors. Reef craters, though isolated, are associated with major colony fragmentation and framework pulverization, with a net permanent loss of reef bio-construction. In contrast, adjacent non-bombarded reef sections have significantly higher benthic spatial relief and biodiversity. We compared benthic communities on 35-50 year-old bomb-cratered coral reefs at Culebra and Vieques Islands, with adjacent non-impacted sites; 2 coral recruit density and fish community structure within and outside craters; and 3 early effects of a rehabilitation effort using low-tech Staghorn coral Acropora cervicornis farming. Reef craters ranged in size from approximately 50 to 400m² and were largely dominated by heavily fragmented, flattened benthos, with coral cover usually below 2% and dominance by non-reef building taxa (i.e., filamentous algal turfs, macroalgae. Benthic spatial heterogeneity was lower within craters which also resulted in a lowered functional value as fish nursery ground. Fish species richness, abundance and biomass, and coral recruit density were lower within craters. Low-tech, community-based approaches to culture, harvest and transplant A. cervicornis into formerly bombarded grounds have proved successful in increasing percent coral cover, benthic spatial heterogeneity, and helping rehabilitate nursery ground functions.

  13. Can you hear me now? Range-testing a submerged passive acoustic receiver array in a Caribbean coral reef habitat

    Science.gov (United States)

    Selby, Thomas H.; Hart, Kristen M.; Fujisaki, Ikuko; Smith, Brian J.; Pollock, Clayton J; Hillis-Star, Zandy M; Lundgren, Ian; Oli, Madan K.

    2016-01-01

    Submerged passive acoustic technology allows researchers to investigate spatial and temporal movement patterns of many marine and freshwater species. The technology uses receivers to detect and record acoustic transmissions emitted from tags attached to an individual. Acoustic signal strength naturally attenuates over distance, but numerous environmental variables also affect the probability a tag is detected. Knowledge of receiver range is crucial for designing acoustic arrays and analyzing telemetry data. Here, we present a method for testing a relatively large-scale receiver array in a dynamic Caribbean coastal environment intended for long-term monitoring of multiple species. The U.S. Geological Survey and several academic institutions in collaboration with resource management at Buck Island Reef National Monument (BIRNM), off the coast of St. Croix, recently deployed a 52 passive acoustic receiver array. We targeted 19 array-representative receivers for range-testing by submersing fixed delay interval range-testing tags at various distance intervals in each cardinal direction from a receiver for a minimum of an hour. Using a generalized linear mixed model (GLMM), we estimated the probability of detection across the array and assessed the effect of water depth, habitat, wind, temperature, and time of day on the probability of detection. The predicted probability of detection across the entire array at 100 m distance from a receiver was 58.2% (95% CI: 44.0–73.0%) and dropped to 26.0% (95% CI: 11.4–39.3%) 200 m from a receiver indicating a somewhat constrained effective detection range. Detection probability varied across habitat classes with the greatest effective detection range occurring in homogenous sand substrate and the smallest in high rugosity reef. Predicted probability of detection across BIRNM highlights potential gaps in coverage using the current array as well as limitations of passive acoustic technology within a complex coral reef

  14. 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

  15. 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

  16. Coral reefs in the Anthropocene

    Science.gov (United States)

    Hughes, Terry P.; Barnes, Michele L.; Bellwood, David R.; Cinner, Joshua E.; Cumming, Graeme S.; Jackson, Jeremy B. C.; Kleypas, Joanie; van de Leemput, Ingrid A.; Lough, Janice M.; Morrison, Tiffany H.; Palumbi, Stephen R.; van Nes, Egbert H.; Scheffer, Marten

    2017-06-01

    Coral reefs support immense biodiversity and provide important ecosystem services to many millions of people. Yet reefs are degrading rapidly in response to numerous anthropogenic drivers. In the coming centuries, reefs will run the gauntlet of climate change, and rising temperatures will transform them into new configurations, unlike anything observed previously by humans. Returning reefs to past configurations is no longer an option. Instead, the global challenge is to steer reefs through the Anthropocene era in a way that maintains their biological functions. Successful navigation of this transition will require radical changes in the science, management and governance of coral reefs.

  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. 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 ...

  19. 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 ...

  20. Bioindication in coral reef ecosystems.

    Science.gov (United States)

    Yap, H T

    1986-01-01

    The concept of bioindication in the sense of the use of organisms for detecting environmental stress has been employed in coral reef conservation and management for the past several years. Important tools are coral growth rates and various community parameters, notably hard coral cover. The present need is the optimal coordination of international efforts for the earliest possible institution of an effective monitoring system.

  1. Isotopic signatures, foraging habitats and trophic relationships between fish and seasnakes on the coral reefs of New Caledonia

    Science.gov (United States)

    Brischoux, F.; Bonnet, X.; Cherel, Y.; Shine, R.

    2011-03-01

    A predator's species, sex and body size can influence the types of prey that it consumes, but why? Do such dietary divergences result from differences in foraging habitats, or reflect differential ability to locate, capture or ingest different types of prey? That question is difficult to answer if foraging occurs in places that preclude direct observation. In New Caledonia, amphibious sea kraits ( Laticauda laticaudata and L. saintgironsi) mostly eat eels—but the species consumed differ between snake species and vary with snake body size and sex. Because the snakes capture eels within crevices on the sea floor, it is not possible to observe snake foraging on any quantitative basis. We used stable isotopes to investigate habitat-divergence and ontogenetic shifts in feeding habits of sympatric species of sea kraits. Similarities in δ15 N (~10.5‰) values suggest that the two snake species occupy similar trophic levels in the coral-reef foodweb. However, δ13C values differed among the eight eel species consumed by snakes, as well as between the two snake species, and were linked to habitat types. Specifically, δ13C differed between soft- vs. hard-substrate eel species, and consistently differed between the soft-bottom forager L. laticaudata (~ -14.7‰) and the hard-bottom forager L. saintgironsi (~ -12.5‰). Differences in isotopic signatures within and between the two sea krait species and their prey were consistent with the hypothesis of habitat-based dietary divergence. Isotopic composition varied with body size within each of the snake species and varied with body size within some eel species, reflecting ontogenetic shifts in feeding habits of both the sea kraits and their prey. Our results support the findings of previous studies based on snake stomach contents, indicating that further studies could usefully expand these isotopic analyses to a broader range of trophic levels, fish species and spatial scales.

  2. 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.

  3. The continuing decline of coral reefs in Bahrain.

    Science.gov (United States)

    Burt, John A; Al-Khalifa, Khalifa; Khalaf, Ebtesam; Alshuwaikh, Bassem; Abdulwahab, Ahmed

    2013-07-30

    Historically coral reefs of Bahrain were among the most extensive in the southern basin of the Arabian Gulf. However, Bahrain's reefs have undergone significant decline in the last four decades as a result of large-scale coastal development and elevated sea surface temperature events. Here we quantitatively surveyed six sites including most major coral reef habitats around Bahrain and a reef located 72 km offshore. Fleshy and turf algae now dominate Bahrain's reefs (mean: 72% cover), and live coral cover is low (mean: 5.1%). Formerly dominant Acropora were not observed at any site. The offshore Bulthama reef had the highest coral cover (16.3%) and species richness (22 of the 23 species observed, 13 of which were exclusive to this site). All reefs for which recent and historical data are available show continued degradation, and it is unlikely that they will recover under continuing coastal development and projected climate change impacts. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. 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... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or...

  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. Multi-taxa coral reef community structure in relation to habitats in the Baa Atoll Man and Biosphere UNESCO Reserve (Maldives), and implications for its conservation

    Science.gov (United States)

    Jimenez, H.; Bigot, L.; Bourmaud, C.; Chabanet, P.; Gravier-Bonnet, N.; Hamel, M. A.; Payri, C.; Mattio, L.; Menou, J. L.; Naeem, S.; Rilwan, Y.; Sattar, S.; Scott, L.; Shiham, A.; Vigliola, L.; Andréfouët, S.

    2012-08-01

    The distribution of species in their environment is largely defined by habitat characteristics. Both species and habitat distributions can be used to define conservation areas, especially in highly diversified ecosystems like coral reefs where biodiversity inventories are lacking. The main objective of this study was to test the relationship between multi-taxa community structure (defined by richness, species lists, and taxonomic distinctness) and habitat typology in the Man and Biosphere UNESCO Reserve of Baa Atoll (Maldives). Species richness per taxon was described at 18 stations located on different habitats mapped using high resolution satellite imagery. A total of 1012 species were described including 178 macroalgae, 173 corals, 121 hydroids, 351 fish and 189 (other) macro-invertebrates. Rarity was extremely high for macro-invertebrates, algae and hydrozoans. The results highlighted a marked difference in species composition between stations for macro-algae and corals but not for other groups (hydroids, fish and macro-invertebrates). These distribution patterns were not strongly correlated to differences in habitat characteristics, which created a weak spatial structure of communities between habitats probably caused by differential exposure of atolls to monsoons and the 1998 bleaching event. Community differences between stations were often due to rarity. Therefore, identifying a network of protected areas that includes occurrences of all species may pose challenges. This is overcome by conservation planning scenarios using medium-size (of the order of 1 km2) management units.

  7. Confronting the coral reef crisis

    Science.gov (United States)

    Bellwood, D. R.; Hughes, T. P.; Folke, C.; Nyström, M.

    2004-06-01

    The worldwide decline of coral reefs calls for an urgent reassessment of current management practices. Confronting large-scale crises requires a major scaling-up of management efforts based on an improved understanding of the ecological processes that underlie reef resilience. Managing for improved resilience, incorporating the role of human activity in shaping ecosystems, provides a basis for coping with uncertainty, future changes and ecological surprises. Here we review the ecological roles of critical functional groups (for both corals and reef fishes) that are fundamental to understanding resilience and avoiding phase shifts from coral dominance to less desirable, degraded ecosystems. We identify striking biogeographic differences in the species richness and composition of functional groups, which highlight the vulnerability of Caribbean reef ecosystems. These findings have profound implications for restoration of degraded reefs, management of fisheries, and the focus on marine protected areas and biodiversity hotspots as priorities for conservation.

  8. Structure, food and shade attract juvenile coral reef fish to mangrove and seagrass habitats: a field experiment

    NARCIS (Netherlands)

    Verweij, M.C.; Nagelkerken, I.; Graaff, de D.; Peeters, M.; Bakker, E.J.; Velde, van der G.

    2006-01-01

    Mangroves and seagrass beds are considered nurseries for juvenile fish, but little experimental evidence exists to elucidate which factors make them attractive habitats. A multifactorial field experiment on the use of these habitats by juvenile reef fish and their behaviour was performed during dayt

  9. Structure, food and shade attract juvenile coral reef fish to mangrove and seagrass habitats: a field experiment.

    NARCIS (Netherlands)

    Verwey, M.C.; Nagelkerken, I.; Graaff, D. de; Peeters, M.; Bakker, E.J.; Velde, G. van der

    2006-01-01

    Mangroves and seagrass beds are considered nurseries for juvenile fish, but little experimental evidence exists to elucidate which factors make them attractive habitats. A multifactorial field experiment on the use of these habitats by juvenile reef fish and their behaviour was performed during dayt

  10. Crossing habitat boundaries : mechanisms underlying cross-habitat utilization by reef fishes

    NARCIS (Netherlands)

    Grol, M.G.G.

    2010-01-01

    This thesis contributes to a better understanding of the nursery-role hypothesis of non-reef habitats for coral reef fishes. Not only fish densities were studied in multiple habitats, but also factors which could drive ontogenetic habitat shifts by fishes, such as habitat structural complexity, food

  11. 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.

  12. The role of turtles as coral reef macroherbivores.

    Directory of Open Access Journals (Sweden)

    Christopher H R Goatley

    Full Text Available 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.

  13. Satellite imaging coral reef resilience at regional scale. A case-study from Saudi Arabia.

    Science.gov (United States)

    Rowlands, Gwilym; Purkis, Sam; Riegl, Bernhard; Metsamaa, Liisa; Bruckner, Andrew; Renaud, Philip

    2012-06-01

    We propose a framework for spatially estimating a proxy for coral reef resilience using remote sensing. Data spanning large areas of coral reef habitat were obtained using the commercial QuickBird satellite, and freely available imagery (NASA, Google Earth). Principles of coral reef ecology, field observation, and remote observations, were combined to devise mapped indices. These capture important and accessible components of coral reef resilience. Indices are divided between factors known to stress corals, and factors incorporating properties of the reef landscape that resist stress or promote coral growth. The first-basis for a remote sensed resilience index (RSRI), an estimate of expected reef resilience, is proposed. Developed for the Red Sea, the framework of our analysis is flexible and with minimal adaptation, could be extended to other reef regions. We aim to stimulate discussion as to use of remote sensing to do more than simply deliver habitat maps of coral reefs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Relationships between structural complexity, coral traits, and reef fish assemblages

    Science.gov (United States)

    Darling, Emily S.; Graham, Nicholas A. J.; Januchowski-Hartley, Fraser A.; Nash, Kirsty L.; Pratchett, Morgan S.; Wilson, Shaun K.

    2017-06-01

    With the ongoing loss of coral cover and the associated flattening of reef architecture, understanding the links between coral habitat and reef fishes is of critical importance. Here, we investigate whether considering coral traits and functional diversity provides new insights into the relationship between structural complexity and reef fish communities, and whether coral traits and community composition can predict structural complexity. Across 157 sites in Seychelles, Maldives, the Chagos Archipelago, and Australia's Great Barrier Reef, we find that structural complexity and reef zone are the strongest and most consistent predictors of reef fish abundance, biomass, species richness, and trophic structure. However, coral traits, diversity, and life histories provided additional predictive power for models of reef fish assemblages, and were key drivers of structural complexity. Our findings highlight that reef complexity relies on living corals—with different traits and life histories—continuing to build carbonate skeletons, and that these nuanced relationships between coral assemblages and habitat complexity can affect the structure of reef fish assemblages. Seascape-level estimates of structural complexity are rapid and cost effective with important implications for the structure and function of fish assemblages, and should be incorporated into monitoring programs.

  15. Threatened corals provide underexplored microbial habitats.

    Directory of Open Access Journals (Sweden)

    Shinichi Sunagawa

    Full Text Available Contemporary in-depth sequencing of environmental samples has provided novel insights into microbial community structures, revealing that their diversity had been previously underestimated. Communities in marine environments are commonly composed of a few dominant taxa and a high number of taxonomically diverse, low-abundance organisms. However, studying the roles and genomic information of these "rare" organisms remains challenging, because little is known about their ecological niches and the environmental conditions to which they respond. Given the current threat to coral reef ecosystems, we investigated the potential of corals to provide highly specialized habitats for bacterial taxa including those that are rarely detected or absent in surrounding reef waters. The analysis of more than 350,000 small subunit ribosomal RNA (16S rRNA sequence tags and almost 2,000 nearly full-length 16S rRNA gene sequences revealed that rare seawater biosphere members are highly abundant or even dominant in diverse Caribbean corals. Closely related corals (in the same genus/family harbored similar bacterial communities. At higher taxonomic levels, however, the similarities of these communities did not correlate with the phylogenetic relationships among corals, opening novel questions about the evolutionary stability of coral-microbial associations. Large proportions of OTUs (28.7-49.1% were unique to the coral species of origin. Analysis of the most dominant ribotypes suggests that many uncovered bacterial taxa exist in coral habitats and await future exploration. Our results indicate that coral species, and by extension other animal hosts, act as specialized habitats of otherwise rare microbes in marine ecosystems. Here, deep sequencing provided insights into coral microbiota at an unparalleled resolution and revealed that corals harbor many bacterial taxa previously not known. Given that two of the coral species investigated are listed as threatened under

  16. From crypsis to mimicry: changes in colour and the configuration of the visual system during ontogenetic habitat transitions in a coral reef fish.

    Science.gov (United States)

    Cortesi, Fabio; Musilová, Zuzana; Stieb, Sara M; Hart, Nathan S; Siebeck, Ulrike E; Cheney, Karen L; Salzburger, Walter; Marshall, N Justin

    2016-08-15

    Animals often change their habitat throughout ontogeny; yet, the triggers for habitat transitions and how these correlate with developmental changes - e.g. physiological, morphological and behavioural - remain largely unknown. Here, we investigated how ontogenetic changes in body coloration and of the visual system relate to habitat transitions in a coral reef fish. Adult dusky dottybacks, Pseudochromis fuscus, are aggressive mimics that change colour to imitate various fishes in their surroundings; however, little is known about the early life stages of this fish. Using a developmental time series in combination with the examination of wild-caught specimens, we revealed that dottybacks change colour twice during development: (i) nearly translucent cryptic pelagic larvae change to a grey camouflage coloration when settling on coral reefs; and (ii) juveniles change to mimic yellow- or brown-coloured fishes when reaching a size capable of consuming juvenile fish prey. Moreover, microspectrophotometric (MSP) and quantitative real-time PCR (qRT-PCR) experiments show developmental changes of the dottyback visual system, including the use of a novel adult-specific visual gene (RH2 opsin). This gene is likely to be co-expressed with other visual pigments to form broad spectral sensitivities that cover the medium-wavelength part of the visible spectrum. Surprisingly, the visual modifications precede changes in habitat and colour, possibly because dottybacks need to first acquire the appropriate visual performance before transitioning into novel life stages.

  17. Benthic habitat map of U.S. Coral Reef Task Force Faga‘alu Bay priority study area, Tutuila, American Samoa

    Science.gov (United States)

    Cochran, Susan A.; Gibbs, Ann E.; D'Antonio, Nicole L.; Storlazzi, Curt D.

    2016-05-18

    The coral reef in Faga‘alu Bay, Tutuila, American Samoa, has suffered numerous natural and anthropogenic stresses. Areas once dominated by live coral are now mostly rubble surfaces covered with turf or macroalgae. In an effort to improve the health and resilience of the coral reef system, the U.S. Coral Reef Task Force selected Faga‘alu Bay as a priority study area. To support these efforts, the U.S. Geological Survey mapped nearly 1 km2 of seafloor to depths of about 60 m. Unconsolidated sediment (predominantly sand) constitutes slightly greater than 50 percent of the seafloor in the mapped area; reef and other hardbottom potentially available for coral recruitment constitute nearly 50 percent of the mapped area. Of this potentially available hardbottom, only slightly greater than 37 percent is covered with at least 10 percent coral, which is fairly evenly distributed between the reef flat, fore reef, and offshore bank/shelf. 

  18. Coral Reef Ecosystems Monitoring Feature Service

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Coral Reef Ecosystem Monitoring feature service hosted on ArcGIS Online provides access to data collected in the Mariana Archipelago by the Coral Reef Ecosystem...

  19. Fisheries management: what chance on coral reefs?

    OpenAIRE

    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.

  20. Climate change and coral reef connectivity

    Science.gov (United States)

    Munday, P. L.; Leis, J. M.; Lough, J. M.; Paris, C. B.; Kingsford, M. J.; Berumen, M. L.; Lambrechts, J.

    2009-06-01

    This review assesses and predicts the impacts that rapid climate change will have on population connectivity in coral reef ecosystems, using fishes as a model group. Increased ocean temperatures are expected to accelerate larval development, potentially leading to reduced pelagic durations and earlier reef-seeking behaviour. Depending on the spatial arrangement of reefs, the expectation would be a reduction in dispersal distances and the spatial scale of connectivity. Small increase in temperature might enhance the number of larvae surviving the pelagic phase, but larger increases are likely to reduce reproductive output and increase larval mortality. Changes to ocean currents could alter the dynamics of larval supply and changes to planktonic productivity could affect how many larvae survive the pelagic stage and their condition at settlement; however, these patterns are likely to vary greatly from place-to-place and projections of how oceanographic features will change in the future lack sufficient certainty and resolution to make robust predictions. Connectivity could also be compromised by the increased fragmentation of reef habitat due to the effects of coral bleaching and ocean acidification. Changes to the spatial and temporal scales of connectivity have implications for the management of coral reef ecosystems, especially the design and placement of marine-protected areas. The size and spacing of protected areas may need to be strategically adjusted if reserve networks are to retain their efficacy in the future.

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

    OpenAIRE

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

    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...

  2. 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.

  3. Coral Reef Ecosystems under Climate Change and Ocean Acidification

    OpenAIRE

    Ove Hoegh-Guldberg; Poloczanska, Elvira S.; William Skirving; Sophie Dove

    2017-01-01

    Coral reefs are found in a wide range of environments, where they provide food and habitat to a large range of organisms as well as providing many other ecological goods and services. Warm-water coral reefs, for example, occupy shallow sunlit, warm, and alkaline waters in order to grow and calcify at the high rates necessary to build and maintain their calcium carbonate structures. At deeper locations (40–150 m), “mesophotic” (low light) coral reefs accumulate calcium carbonate at much lower ...

  4. ENERGETIC EXTREMES IN A HOSTILE HABITAT: FISH LOCOMOTION ON WAVE-SWEPT CORAL REEFS

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2010-01-01

    Fulton, C.J., Johansen, J. L. and Steffensen, J.F. Abstract: Shallow wave-swept habitats are a major challenge for fish locomotion, where crashing waves produce water flows equivalent to cyclone-force winds. Here we document the exceptional locomotor energetics of Bluelined wrasse (Stethojulis...

  5. Geographic coupling of juvenile and adult habitat shapes spatial population dynamics of a coral reef fish

    NARCIS (Netherlands)

    Huijbers, C.M.; Nagelekerken, I.; Debrot, A.O.; Jongejans, E.

    2013-01-01

    Marine spatial population dynamics are often addressed with a focus on larval dispersal, without taking into account movement behavior of individuals in later life stages. Processes occurring during demersal life stages may also drive spatial population dynamics if habitat quality is perceived diffe

  6. Coral reef fish assemblages at Clipperton Atoll (Eastern Tropical Pacific and their relationship with coral cover

    Directory of Open Access Journals (Sweden)

    Aurora M. Ricart

    2016-11-01

    Full Text Available Clipperton Atoll, one of the most isolated coral reefs worldwide, is of great scientific interest due to its geomorphology and high levels of endemism. This study explored the reef fish assemblage structure of Clipperton Atoll and its relationship with live coral cover. Nine stations were sampled at three sites and three depths (6, 12 and 20 m around the reef, measuring fish species richness and biomass and hermatypic coral cover (at genus level. We evaluated variation in species richness, biomass and diversity of fish assemblages among sites and depths, as well as the relationship between the entire fish assemblage composition and live coral cover. The results showed that species richness and biomass were similar among sites, but differed across depths, increasing with depth. In contrast, diversity differed among sites but not among depths. Multivariate analyses indicated that fish assemblage composition differed among sites and depths in relation to changes in cover of coral of the genera Pocillopora, Porites, Pavona and Leptoseris, which dominate at different depths. The results showed that fish species richness and diversity were low at Clipperton Atoll and that, in isolated coral reefs with a low habitat heterogeneity and low human disturbance, live coral cover has a significant influence on the spatial variation of the reef fish assemblages. This study highlights the importance of coral habitat structure in shaping coral reef fish assemblages.

  7. Sensing coral reef connectivity pathways from space

    KAUST Repository

    Raitsos, Dionysios E.

    2017-08-18

    Coral reefs rely on inter-habitat connectivity to maintain gene flow, biodiversity and ecosystem resilience. Coral reef communities of the Red Sea exhibit remarkable genetic homogeneity across most of the Arabian Peninsula coastline, with a genetic break towards the southern part of the basin. While previous studies have attributed these patterns to environmental heterogeneity, we hypothesize that they may also emerge as a result of dynamic circulation flow; yet, such linkages remain undemonstrated. Here, we integrate satellite-derived biophysical observations, particle dispersion model simulations, genetic population data and ship-borne in situ profiles to assess reef connectivity in the Red Sea. We simulated long-term (>20 yrs.) connectivity patterns driven by remotely-sensed sea surface height and evaluated results against estimates of genetic distance among populations of anemonefish, Amphiprion bicinctus, along the eastern Red Sea coastline. Predicted connectivity was remarkably consistent with genetic population data, demonstrating that circulation features (eddies, surface currents) formulate physical pathways for gene flow. The southern basin has lower physical connectivity than elsewhere, agreeing with known genetic structure of coral reef organisms. The central Red Sea provides key source regions, meriting conservation priority. Our analysis demonstrates a cost-effective tool to estimate biophysical connectivity remotely, supporting coastal management in data-limited regions.

  8. Coral communities of the remote atoll reefs in the Nansha Islands, southern South China Sea.

    Science.gov (United States)

    Zhao, M X; Yu, K F; Shi, Q; Chen, T R; Zhang, H L; Chen, T G

    2013-09-01

    During the months of May and June in the year 2007, a survey was conducted regarding coral reef communities in the remote atolls (Zhubi Reef and Meiji Reef) of Nansha Islands, southern South China Sea. The goals of the survey were to: (1) for the first time, compile a scleractinian coral check-list; (2) estimate the total richness, coral cover, and growth forms of the community; and (3) describe preliminary patterns of community structure according to geomorphological units. Findings of this survey revealed a total of 120 species of scleractinia belonging to 40 genera, while the average coral cover was 21 %, ranging from less than 10 % to higher than 50 %. Branching and massive corals were also found to be the most important growth forms of the whole coral community, while Acropora, Montipora, and Porites were the three dominant genera in the overall region, with their contributions to total coral cover measuring 21, 22, and 23 %, respectively. Overall, coral communities of the Nansha Islands were in a relative healthy condition with high species diversity and coral cover. Spatial pattern of coral communities existed among various geomorphological units. Mean coral cover was highest in the patch reef within the lagoon, followed by the fore reef slope, reef flat, and lagoon slope. The greatest contributors to total coral cover were branching Acropora (45 %) in the lagoon slope, branching Montipora (44 %) in the reef flat, and massive Porites (51 %) in the patch reef. Coral cover in the fore reef revealed a greater range of genera than in other habitats. The leeward fore reef slope had higher coral cover (> 50 %) when compared with the windward slope (coral communities of the inner reef flat were characterized by higher coral cover (27 %) and dominant branching Montipora corals, while lower coral cover (4 %) was dominated by Psammocora with massive growth forms on the outer reef flat. Destructive fishing and coral bleaching were two major threats to coral communities

  9. Coral Reef Ecosystems under Climate Change and Ocean Acidification

    Directory of Open Access Journals (Sweden)

    Ove Hoegh-Guldberg

    2017-05-01

    Full Text Available Coral reefs are found in a wide range of environments, where they provide food and habitat to a large range of organisms as well as providing many other ecological goods and services. Warm-water coral reefs, for example, occupy shallow sunlit, warm, and alkaline waters in order to grow and calcify at the high rates necessary to build and maintain their calcium carbonate structures. At deeper locations (40–150 m, “mesophotic” (low light coral reefs accumulate calcium carbonate at much lower rates (if at all in some cases yet remain important as habitat for a wide range of organisms, including those important for fisheries. Finally, even deeper, down to 2,000 m or more, the so-called “cold-water” coral reefs are found in the dark depths. Despite their importance, coral reefs are facing significant challenges from human activities including pollution, over-harvesting, physical destruction, and climate change. In the latter case, even lower greenhouse gas emission scenarios (such as Representative Concentration Pathway RCP 4.5 are likely drive the elimination of most warm-water coral reefs by 2040–2050. Cold-water corals are also threatened by warming temperatures and ocean acidification although evidence of the direct effect of climate change is less clear. Evidence that coral reefs can adapt at rates which are sufficient for them to keep up with rapid ocean warming and acidification is minimal, especially given that corals are long-lived and hence have slow rates of evolution. Conclusions that coral reefs will migrate to higher latitudes as they warm are equally unfounded, with the observations of tropical species appearing at high latitudes “necessary but not sufficient” evidence that entire coral reef ecosystems are shifting. On the contrary, coral reefs are likely to degrade rapidly over the next 20 years, presenting fundamental challenges for the 500 million people who derive food, income, coastal protection, and a range of

  10. 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.

  11. New tool to manage coral reefs

    Science.gov (United States)

    Showstack, Randy

    The National Oceanic and Atmospheric Administration is making available a new tool for coral reef managers to monitor the cumulative thermal stress of several coral reefs around the world, including the Great Barrier Reef, and reefs by the Galapagos Islands, the agency announced on 25 February.The agency's "Degree Heating Weeks" product uses satellite-derived information to allow continuous monitoring of the extent and acuteness of thermal stress, which are key predictors of coral bleaching, and which contribute to coral reef degradation.

  12. 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...

  13. 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 or...

  14. Mapping Oyster Reef Habitats in Mobile Bay

    Science.gov (United States)

    Bolte, Danielle

    2011-01-01

    Oyster reefs around the world are declining rapidly, and although they haven t received as much attention as coral reefs, they are just as important to their local ecosystems and economies. Oyster reefs provide habitats for many species of fish, invertebrates, and crustaceans, as well as the next generations of oysters. Oysters are also harvested from many of these reefs and are an important segment of many local economies, including that of Mobile Bay, where oysters rank in the top five commercial marine species both by landed weight and by dollar value. Although the remaining Mobile Bay oyster reefs are some of the least degraded in the world, projected climate change could have dramatic effects on the health of these important ecosystems. The viability of oyster reefs depends on water depth and temperature, appropriate pH and salinity levels, and the amount of dissolved oxygen in the water. Projected increases in sea level, changes in precipitation and runoff patterns, and changes in pH resulting from increases in the amount of carbon dioxide dissolved in the oceans could all affect the viability of oyster reefs in the future. Human activities such as dredging and unsustainable harvesting practices are also adversely impacting the oyster reefs. Fortunately, several projects are already under way to help rebuild or support existing or previously existing oyster reefs. The success of these projects will depend on the local effects of climate change on the current and potential habitats and man s ability to recognize and halt unsustainable harvesting practices. As the extent and health of the reefs changes, it will have impacts on the Mobile Bay ecosystem and economy, changing the resources available to the people who live there and to the rest of the country, since Mobile Bay is an important national source of seafood. This project identified potential climate change impacts on the oyster reefs of Mobile Bay, including the possible addition of newly viable

  15. Hydrodynamic Regimes Affect Coral Reef Resilience to Ocean Acidification

    Science.gov (United States)

    Teneva, L. T.; Dunbar, R. B.; Koseff, J. R.; Fleischfresser, J. D.; Koweek, D.

    2013-05-01

    Caribbean reefs hold tremendous value as sources of food, income, coastal protection, in addition to their cultural significance. Recently, studies showed that Caribbean reef growth has been surpassed in places by excessive rates of erosion due to climate change. The rates of coral reef response to ocean pH changes and warming and the implications for ecosystem resilience remain largely unknown. One way to investigate the potential structural resilience of reefs to climate change is to measure the physical oceanographic conditions in the area. Determining the hydrodynamic regimes and residence time of water in a particular reef environment is crucial to understanding the rates of future warming and acidification a reef site would experience. Our work on Pacific Islands' hydrodynamics - Central Equatorial Pacific, Great Barrier Reef, and Western Pacific -- would be of interest to Caribbean physical oceanographers and coral reef scientists. We use a combination of Acoustic Doppler Current Profilers, Acoustic Doppler Velocimeters, temperature and salinity sensors, and pressure sensors to characterize reef hydrodynamic regimes. Our work indicates that shallower, more protected reef habitats are characterized by longer residence times, their biological signals are strongly tidally modulated, essentially subjecting such habitats to higher rates of warming and acidification in the future. Reef crest environments and fore reef habitats, on the other hand, are well-mixed with open-ocean water. The hydrodynamic regimes there condition such reef sites to more attenuated temperature and pH ranges, conditions more typical of the open ocean. Our work suggests that investigating the geomorphology and resulting localized hydrodynamics in a reef area can provide insights into the relative rates at which a reef could resist or succumb to impacts of ocean acidification. Such information for different reef islands, in the Pacific or Caribbean basins, could provide helpful insights

  16. Dynamic stability of coral reefs on the west Australian coast.

    Science.gov (United States)

    Speed, Conrad W; Babcock, Russ C; Bancroft, Kevin P; Beckley, Lynnath E; Bellchambers, Lynda M; Depczynski, Martial; Field, Stuart N; Friedman, Kim J; Gilmour, James P; Hobbs, Jean-Paul A; Kobryn, Halina T; Moore, James A Y; Nutt, Christopher D; Shedrawi, George; Thomson, Damian P; Wilson, Shaun K

    2013-01-01

    Monitoring changes in coral cover and composition through space and time can provide insights to reef health and assist the focus of management and conservation efforts. We used a meta-analytical approach to assess coral cover data across latitudes 10-35°S along the west Australian coast, including 25 years of data from the Ningaloo region. Current estimates of coral cover ranged between 3 and 44% in coral habitats. Coral communities in the northern regions were dominated by corals from the families Acroporidae and Poritidae, which became less common at higher latitudes. At Ningaloo Reef coral cover has remained relatively stable through time (∼28%), although north-eastern and southern areas have experienced significant declines in overall cover. These declines are likely related to periodic disturbances such as cyclones and thermal anomalies, which were particularly noticeable around 1998/1999 and 2010/2011. Linear mixed effects models (LME) suggest latitude explains 10% of the deviance in coral cover through time at Ningaloo. Acroporidae has decreased in abundance relative to other common families at Ningaloo in the south, which might be related to persistence of more thermally and mechanically tolerant families. We identify regions where quantitative time-series data on coral cover and composition are lacking, particularly in north-western Australia. Standardising routine monitoring methods used by management and research agencies at these, and other locations, would allow a more robust assessment of coral condition and a better basis for conservation of coral reefs.

  17. Spatial dynamics of benthic competition on coral reefs.

    Science.gov (United States)

    Sandin, Stuart A; McNamara, Dylan E

    2012-04-01

    The community structure of sedentary organisms is largely controlled by the outcome of direct competition for space. Understanding factors defining competitive outcomes among neighbors is thus critical for predicting large-scale changes, such as transitions to alternate states within coral reefs. Using a spatially explicit model, we explored the importance of variation in two spatial properties in benthic dynamics on coral reefs: (1) patterns of herbivory are spatially distinct between fishes and sea urchins and (2) there is wide variation in the areal extent into which different coral species can expand. We reveal that the size-specific, competitive asymmetry of corals versus fleshy algae highlights the significance of spatial patterning of herbivory and of coral growth. Spatial dynamics that alter the demographic importance of coral recruitment and maturation have profound effects on the emergent structure of the reef benthic community. Spatially constrained herbivory (as by sea urchins) is more effective than spatially unconstrained herbivory (as by many fish) at opening space for the time needed for corals to settle and to recruit to the adult population. Further, spatially unconstrained coral growth (as by many branching coral species) reduces the number of recruitment events needed to fill a habitat with coral relative to more spatially constrained growth (as by many massive species). Our model predicts that widespread mortality of branching corals (e.g., Acropora spp) and herbivorous sea urchins (particularly Diadema antillarum) in the Caribbean has greatly reduced the potential for restoration across the region.

  18. Coral reef fish smell leaves to find island homes

    Science.gov (United States)

    Dixson, Danielle L; Jones, Geoffrey P; Munday, Philip L; Planes, Serge; Pratchett, Morgan S; Srinivasan, Maya; Syms, Craig; Thorrold, Simon R

    2008-01-01

    Recent studies have shown that some coral reef fish larvae return to natal reefs, while others disperse to distant reefs. However, the sensory mechanisms used to find settlement sites are poorly understood. One hypothesis is that larvae use olfactory cues to navigate home or find other suitable reef habitats. Here we show a strong association between the clownfish Amphiprion percula and coral reefs surrounding offshore islands in Papua New Guinea. Host anemones and A. percula are particularly abundant in shallow water beneath overhanging rainforest vegetation. A series of experiments were carried out using paired-choice flumes to evaluate the potential role of water-borne olfactory cues in finding islands. Recently settled A. percula exhibited strong preferences for: (i) water from reefs with islands over water from reefs without islands; (ii) water collected near islands over water collected offshore; and (iii) water treated with either anemones or leaves from rainforest vegetation. Laboratory reared-juveniles exhibited the same positive response to anemones and rainforest vegetation, suggesting that olfactory preferences are innate rather than learned. We hypothesize that A. percula use a suite of olfactory stimuli to locate vegetated islands, which may explain the high levels of self-recruitment on island reefs. This previously unrecognized link between coral reefs and island vegetation argues for the integrated management of these pristine tropical habitats. PMID:18755672

  19. 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

  20. 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...

  1. Global warming and coral reefs

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    photosynthesis and survival of coral planulae, etc. Unfortunately, no such studies have been carried out on Indian corals so far, and a visualization of what will happen to Indian reefs if sea level rises rapidly will have to be constructed based on such dat... susceptible, as plankton living near the sea surface, and as hosts deriving nutri tional benefits from zooxanthtllar photosynthesis, which itself is susceptible to UV-B damage. Contrary to the misconception that UV is absorbed by the sea water, UV penetrates...

  2. 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.

  3. Cyanobacteria in coral reef ecosystems : a review

    OpenAIRE

    Charpy, L.; Casareto, B.E.; Langlade, M. J.; Suzuki, Y.

    2012-01-01

    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 nitrog...

  4. 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.

  5. 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.

  6. Otolith growth of Springer's demoiselle, Chrysiptera springeri (Pomacentridae, Allen & Lubbock), on a protected and non-protected coral reef

    DEFF Research Database (Denmark)

    Retzel, A.; Hansen, A.D.; Grønkjær, P.

    2007-01-01

    The structural complexity of coral reefs is important for their function as shelter and feeding habitats for coral reef fishes, but physical disturbance by human activities often reduce complexity of the reefs by selectively destroying fragile and more complex coral species. The damselfish Springer......'s demoiselle Chrysiptera springeri primarily utilize complex coral heads for shelter and are hence vulnerable to human disturbance. In order to evaluate the potential effect of habitat degradation on juvenile fish growth, coral reef cover, fish age at settling and otolith growth, juvenile Springer's demoiselle...... was investigated on a protected and non-protected coral reef in Darvel Bay, Borneo. The protected reef had higher coverage of complex branching corals and exhibited a more complex 3-dimensional structure than the non-protected reef. Springer's demoiselle settled at the same age on non-protected and protected reefs...

  7. ENERGETIC EXTREMES IN REEF FISH OCCUPYING HARSH HABITATS

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2009-01-01

    document how relatively small changes in fin morphology has afforded some coral reef fish taxa with exceptional locomotor performance and energetic efficiency, and how this key attribute may have played a key role in the evolution and ecology of several diverse Indo-Pacific reef fish families. Using......-finned counterparts. We discuss how such differences in locomotor efficiency are pivotal to the habitat-use of these fishes, and how eco-energetic models may be used to provide new insights into spatial variations in fish demography and ecology among coral reef habitat zones....

  8. 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.

  9. How will coral reef fish communities respond to climate-driven disturbances? Insight from landscape-scale perturbations.

    Science.gov (United States)

    Adam, Thomas C; Brooks, Andrew J; Holbrook, Sally J; Schmitt, Russell J; Washburn, Libe; Bernardi, Giacomo

    2014-09-01

    Global climate change is rapidly altering disturbance regimes in many ecosystems including coral reefs, yet the long-term impacts of these changes on ecosystem structure and function are difficult to predict. A major ecosystem service provided by coral reefs is the provisioning of physical habitat for other organisms, and consequently, many of the effects of climate change on coral reefs will be mediated by their impacts on habitat structure. Therefore, there is an urgent need to understand the independent and combined effects of coral mortality and loss of physical habitat on reef-associated biota. Here, we use a unique series of events affecting the coral reefs around the Pacific island of Moorea, French Polynesia to differentiate between the impacts of coral mortality and the degradation of physical habitat on the structure of reef fish communities. We found that, by removing large amounts of physical habitat, a tropical cyclone had larger impacts on reef fish communities than an outbreak of coral-eating sea stars that caused widespread coral mortality but left the physical structure intact. In addition, the impacts of declining structural complexity on reef fish assemblages accelerated as structure became increasingly rare. Structure provided by dead coral colonies can take up to decades to erode following coral mortality, and, consequently, our results suggest that predictions based on short-term studies are likely to grossly underestimate the long-term impacts of coral decline on reef fish communities.

  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 reef-coral habitat ≤30 m will preclude coral growth and reef development. Thus, protecting the turbid nearshore refuges identified in this study, particularly in the northwestern Hawaiian Islands, the northern Philippines, the Ryukyu Islands (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.

  11. Nitrification in reef corals

    Digital Repository Service at National Institute of Oceanography (India)

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

    cells cmP2 (Drew 1972), it is reasonable to expect that nitrification will have to compete with assimilatory re- moval of NH,+. The relative importance of NH4+ flux in these two pathways can be evaluated with the present data on NO,- production... about the means in the es- timates, this correspondence shows that bacterial nitrification effectively competes with autotrophic uptake of NH,+ in coral- zooxanthellae symbiosis. In fact, our nitrification rates would be underestimates since losses...

  12. 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 Force...

  13. 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...

  14. 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.

  15. 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.

  16. Photography of Coral Reefs from ISS

    Science.gov (United States)

    Robinson, Julie A.

    2009-01-01

    This viewgraph presentation reviews the uses of photography from the International Space Station (ISS) in studying Earth's coral reefs. The photographs include reefs in various oceans . The photographs have uses for science in assisting NASA mapping initiatives, distribution worldwide through ReefBase, and by biologist in the field.

  17. CORAL REEF BIOLOGICAL CRITERIA: USING THE CLEAN ...

    Science.gov (United States)

    Coral reefs are declining at unprecedented rates worldwide due to multiple interactive stressors including climate change and land-based sources of pollution. The Clean Water Act (CWA) can be a powerful legal instrument for protecting water resources, including the biological inhabitants of coral reefs. The objective of the CWA is to restore and maintain the chemical, physical and biological integrity of water resources. Coral reef protection and restoration under the Clean Water Act begins with water quality standards - provisions of state or Federal law that consist of a designated use(s) for the waters of the United States and water quality criteria sufficient to protect the uses. Aquatic life use is the designated use that is measured by biological criteria (biocriteria). Biocriteria are expectations set by a jurisdiction for the quality and quantity of living aquatic resources in a defined waterbody. Biocriteria are an important addition to existing management tools for coral reef ecosystems. The Technical Support Document “Coral Reef Biological Criteria: Using the Clean Water Act to Protect a National Treasure” will provide a framework to aid States and Territories in their development, adoption, and implementation of coral reef biocriteria in their respective water quality standards. The Technical Support Document “Coral Reef Biological Criteria: Using the Clean Water Act to Protect a National Treasure” will provide a framework for coral re

  18. Habitat degradation is threatening reef replenishment by making fish fearless.

    Science.gov (United States)

    Lönnstedt, Oona M; McCormick, Mark I; Chivers, Douglas P; Ferrari, Maud C O

    2014-09-01

    Habitat degradation is one of the 'Big Five' drivers of biodiversity loss. However, the mechanisms responsible for this progressive loss of biodiversity are poorly understood. In marine ecosystems, corals play the role of ecosystem engineers, providing essential habitat for hundreds of thousands of species and hence their health is crucial to the stability of the whole ecosystem. Climate change is causing coral bleaching and degradation, and while this has been known for a while, little do we know about the cascading consequences of these events on the complex interrelationships between predators and their prey. The goal of our study was to investigate, under completely natural conditions, the effect of coral degradation on predator-prey interactions. Settlement stage ambon damselfish (Pomacentrus amboinensis), a common tropical fish, were released on patches of healthy or dead corals, and their behaviours in situ were measured, along with their response to injured conspecific cues, a common risk indicator. This study also explored the effect of habitat degradation on natural levels of mortality at a critical life-history transition. We found that juveniles in dead corals displayed risk-prone behaviours, sitting further away and higher up on the reef patch, and failed to respond to predation cues, compared to those on live coral patches. In addition, in situ survival experiments over 48 h indicated that juveniles on dead coral habitats had a 75% increase in predation-related mortality, compared to fish released on live, healthy coral habitats. Our results provide the first of many potential mechanisms through which habitat degradation can impact the relationship between prey and predators in the coral reef ecosystem. As the proportion of dead coral increases, the recruitment and replenishment of coral reef fishes will be threatened, and so will the level of diversity in these biodiversity hot spots.

  19. High coral cover on a mesophotic, subtropical island platform at the limits of coral reef growth

    Science.gov (United States)

    Linklater, Michelle; Carroll, Andrew G.; Hamylton, Sarah M.; Jordan, Alan R.; Brooke, Brendan P.; Nichol, Scott L.; Woodroffe, Colin D.

    2016-11-01

    Balls Pyramid is a volcanic monolith rising 552 m from the Tasman Sea, 24 km southeast of the Pacific Ocean's southernmost modern coral reef at Lord Howe Island. High resolution seabed mapping of the shelf surrounding Balls Pyramid has revealed an extensive submerged reef structure in 30-50 m water depth, covering an area of 87 km2. Benthic community composition analysis of high-resolution still images revealed abundant scleractinian corals on the submerged reef, extending to a maximum depth of 94 m. Scleractinian coral occurred predominantly in 30-40 m depth where it comprised 13.3% of benthic cover within this depth range. Average scleractinian coral cover for all transects was 6.7±12.2%, with the highest average transect cover of 19.4±14.3% and up to 84% cover recorded for an individual still image. The remaining substrate comprised mixed benthos with veneers of carbonate sand. Benthic data were shown to significantly relate to the underlying geomorphology. BVSTEP analyses identified depth and backscatter as the strongest correlating explanatory variables driving benthic community structure. The prevalence of scleractinian corals on the submerged reef features at Balls Pyramid, and the mesophotic depths to which these corals extend, demonstrates the important role of this subtropical island shelf as habitat for modern coral communities in the southwest Pacific Ocean. As Balls Pyramid is located beyond the known latitudinal limit of coral reef formation, these findings have important implications for potential coral reef range expansion and deep reef refugia under a changing climate.

  20. 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

  1. 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.

  2. The effectiveness of coral reefs for coastal hazard risk reduction and adaptation

    Science.gov (United States)

    Ferrario, Filippo; Beck, Michael W.; Storlazzi, Curt D.; Micheli, Fiorenza; Shepard, Christine C.; Airoldi, Laura

    2014-01-01

    The world’s coastal zones are experiencing rapid development and an increase in storms and flooding. These hazards put coastal communities at heightened risk, which may increase with habitat loss. Here we analyse globally the role and cost effectiveness of coral reefs in risk reduction. Meta-analyses reveal that coral reefs provide substantial protection against natural hazards by reducing wave energy by an average of 97%. Reef crests alone dissipate most of this energy (86%). There are 100 million or more people who may receive risk reduction benefits from reefs or bear hazard mitigation and adaptation costs if reefs are degraded. We show that coral reefs can provide comparable wave attenuation benefits to artificial defences such as breakwaters, and reef defences can be enhanced cost effectively. Reefs face growing threats yet there is opportunity to guide adaptation and hazard mitigation investments towards reef restoration to strengthen this first line of coastal defence.

  3. The dynamics of architectural complexity on coral reefs under climate change.

    Science.gov (United States)

    Bozec, Yves-Marie; Alvarez-Filip, Lorenzo; Mumby, Peter J

    2015-01-01

    One striking feature of coral reef ecosystems is the complex benthic architecture which supports diverse and abundant fauna, particularly of reef fish. Reef-building corals are in decline worldwide, with a corresponding loss of live coral cover resulting in a loss of architectural complexity. Understanding the dynamics of the reef architecture is therefore important to envision the ability of corals to maintain functional habitats in an era of climate change. Here, we develop a mechanistic model of reef topographical complexity for contemporary Caribbean reefs. The model describes the dynamics of corals and other benthic taxa under climate-driven disturbances (hurricanes and coral bleaching). Corals have a simplified shape with explicit diameter and height, allowing species-specific calculation of their colony surface and volume. Growth and the mechanical (hurricanes) and biological erosion (parrotfish) of carbonate skeletons are important in driving the pace of extension/reduction in the upper reef surface, the net outcome being quantified by a simple surface roughness index (reef rugosity). The model accurately simulated the decadal changes of coral cover observed in Cozumel (Mexico) between 1984 and 2008, and provided a realistic hindcast of coral colony-scale (1-10 m) changing rugosity over the same period. We then projected future changes of Caribbean reef rugosity in response to global warming. Under severe and frequent thermal stress, the model predicted a dramatic loss of rugosity over the next two or three decades. Critically, reefs with managed parrotfish populations were able to delay the general loss of architectural complexity, as the benefits of grazing in maintaining living coral outweighed the bioerosion of dead coral skeletons. Overall, this model provides the first explicit projections of reef rugosity in a warming climate, and highlights the need of combining local (protecting and restoring high grazing) to global (mitigation of greenhouse gas

  4. 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.

  5. 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.

  6. 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 Utility...

  7. A geological perspective on the degradation and conservation of western Atlantic coral reefs

    Science.gov (United States)

    Kuffner, Ilsa B.; Toth, Lauren T.

    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

  8. Facilitation in Caribbean coral reefs: high densities of staghorn coral foster greater coral condition and reef fish composition.

    Science.gov (United States)

    Huntington, Brittany E; Miller, Margaret W; Pausch, Rachel; Richter, Lee

    2017-05-01

    Recovery of the threatened staghorn coral (Acropora cervicornis) is posited to play a key role in Caribbean reef resilience. At four Caribbean locations (including one restored and three extant populations), we quantified characteristics of contemporary staghorn coral across increasing conspecific densities, and investigated a hypothesis of facilitation between staghorn coral and reef fishes. High staghorn densities in the Dry Tortugas exhibited significantly less partial mortality, higher branch growth, and supported greater fish abundances compared to lower densities within the same population. In contrast, partial mortality, branch growth, and fish community composition did not vary with staghorn density at the three other study locations where staghorn densities were lower overall. This suggests that density-dependent effects between the coral and fish community may only manifest at high staghorn densities. We then evaluated one facilitative mechanism for such density-dependence, whereby abundant fishes sheltering in dense staghorn aggregations deliver nutrients back to the coral, fueling faster coral growth, thereby creating more fish habitat. Indeed, dense staghorn aggregations within the Dry Tortugas exhibited significantly higher growth rates, tissue nitrogen, and zooxanthellae densities than sparse aggregations. Similarly, higher tissue nitrogen was induced in a macroalgae bioassay outplanted into the same dense and sparse aggregations, confirming greater bioavailability of nutrients at high staghorn densities. Our findings inform staghorn restoration efforts, suggesting that the most effective targets may be higher coral densities than previously thought. These coral-dense aggregations may reap the benefits of positive facilitation between the staghorn and fish community, favoring the growth and survivorship of this threatened species.

  9. New perspectives on ecological mechanisms affecting coral recruitment on reefs

    NARCIS (Netherlands)

    Ritson-Williams, R.; Arnold, S.N.; Fogarty, N.D.; Steneck, R.S.; Vermeij, M.J.A.; Paul, V.J.

    2009-01-01

    Coral mortality has increased in recent decades, making coral recruitment more important than ever in sustaining coral reef ecosystems and contributing to their resilience. This review summarizes existing information on ecological factors affecting scleractinian coral recruitment. Successful recruit

  10. New perspectives on ecological mechanisms affecting coral recruitment on reefs

    NARCIS (Netherlands)

    Ritson-Williams, R.; Arnold, S.N.; Fogarty, N.D.; Steneck, R.S.; Vermeij, M.J.A.; Paul, V.J.

    2009-01-01

    Coral mortality has increased in recent decades, making coral recruitment more important than ever in sustaining coral reef ecosystems and contributing to their resilience. This review summarizes existing information on ecological factors affecting scleractinian coral recruitment. Successful

  11. Coral reefs on the edge? Carbon chemistry on inshore reefs of the great barrier reef.

    Science.gov (United States)

    Uthicke, Sven; Furnas, Miles; Lønborg, Christian

    2014-01-01

    While increasing atmospheric carbon dioxide (CO2) concentration alters global water chemistry (Ocean Acidification; OA), the degree of changes vary on local and regional spatial scales. Inshore fringing coral reefs of the Great Barrier Reef (GBR) are subjected to a variety of local pressures, and some sites may already be marginal habitats for corals. The spatial and temporal variation in directly measured parameters: Total Alkalinity (TA) and dissolved inorganic carbon (DIC) concentration, and derived parameters: partial pressure of CO2 (pCO2); pH and aragonite saturation state (Ωar) were measured at 14 inshore reefs over a two year period in the GBR region. Total Alkalinity varied between 2069 and 2364 µmol kg-1 and DIC concentrations ranged from 1846 to 2099 µmol kg-1. This resulted in pCO2 concentrations from 340 to 554 µatm, with higher values during the wet seasons and pCO2 on inshore reefs distinctly above atmospheric values. However, due to temperature effects, Ωar was not further reduced in the wet season. Aragonite saturation on inshore reefs was consistently lower and pCO2 higher than on GBR reefs further offshore. Thermodynamic effects contribute to this, and anthropogenic runoff may also contribute by altering productivity (P), respiration (R) and P/R ratios. Compared to surveys 18 and 30 years ago, pCO2 on GBR mid- and outer-shelf reefs has risen at the same rate as atmospheric values (∼1.7 µatm yr-1) over 30 years. By contrast, values on inshore reefs have increased at 2.5 to 3 times higher rates. Thus, pCO2 levels on inshore reefs have disproportionately increased compared to atmospheric levels. Our study suggests that inshore GBR reefs are more vulnerable to OA and have less buffering capacity compared to offshore reefs. This may be caused by anthropogenically induced trophic changes in the water column and benthos of inshore reefs subjected to land runoff.

  12. Coral reefs on the edge? Carbon chemistry on inshore reefs of the great barrier reef.

    Directory of Open Access Journals (Sweden)

    Sven Uthicke

    Full Text Available While increasing atmospheric carbon dioxide (CO2 concentration alters global water chemistry (Ocean Acidification; OA, the degree of changes vary on local and regional spatial scales. Inshore fringing coral reefs of the Great Barrier Reef (GBR are subjected to a variety of local pressures, and some sites may already be marginal habitats for corals. The spatial and temporal variation in directly measured parameters: Total Alkalinity (TA and dissolved inorganic carbon (DIC concentration, and derived parameters: partial pressure of CO2 (pCO2; pH and aragonite saturation state (Ωar were measured at 14 inshore reefs over a two year period in the GBR region. Total Alkalinity varied between 2069 and 2364 µmol kg-1 and DIC concentrations ranged from 1846 to 2099 µmol kg-1. This resulted in pCO2 concentrations from 340 to 554 µatm, with higher values during the wet seasons and pCO2 on inshore reefs distinctly above atmospheric values. However, due to temperature effects, Ωar was not further reduced in the wet season. Aragonite saturation on inshore reefs was consistently lower and pCO2 higher than on GBR reefs further offshore. Thermodynamic effects contribute to this, and anthropogenic runoff may also contribute by altering productivity (P, respiration (R and P/R ratios. Compared to surveys 18 and 30 years ago, pCO2 on GBR mid- and outer-shelf reefs has risen at the same rate as atmospheric values (∼1.7 µatm yr-1 over 30 years. By contrast, values on inshore reefs have increased at 2.5 to 3 times higher rates. Thus, pCO2 levels on inshore reefs have disproportionately increased compared to atmospheric levels. Our study suggests that inshore GBR reefs are more vulnerable to OA and have less buffering capacity compared to offshore reefs. This may be caused by anthropogenically induced trophic changes in the water column and benthos of inshore reefs subjected to land runoff.

  13. Coral Reefs on the Edge? Carbon Chemistry on Inshore Reefs of the Great Barrier Reef

    Science.gov (United States)

    Uthicke, Sven; Furnas, Miles; Lønborg, Christian

    2014-01-01

    While increasing atmospheric carbon dioxide (CO2) concentration alters global water chemistry (Ocean Acidification; OA), the degree of changes vary on local and regional spatial scales. Inshore fringing coral reefs of the Great Barrier Reef (GBR) are subjected to a variety of local pressures, and some sites may already be marginal habitats for corals. The spatial and temporal variation in directly measured parameters: Total Alkalinity (TA) and dissolved inorganic carbon (DIC) concentration, and derived parameters: partial pressure of CO2 (pCO2); pH and aragonite saturation state (Ωar) were measured at 14 inshore reefs over a two year period in the GBR region. Total Alkalinity varied between 2069 and 2364 µmol kg−1 and DIC concentrations ranged from 1846 to 2099 µmol kg−1. This resulted in pCO2 concentrations from 340 to 554 µatm, with higher values during the wet seasons and pCO2 on inshore reefs distinctly above atmospheric values. However, due to temperature effects, Ωar was not further reduced in the wet season. Aragonite saturation on inshore reefs was consistently lower and pCO2 higher than on GBR reefs further offshore. Thermodynamic effects contribute to this, and anthropogenic runoff may also contribute by altering productivity (P), respiration (R) and P/R ratios. Compared to surveys 18 and 30 years ago, pCO2 on GBR mid- and outer-shelf reefs has risen at the same rate as atmospheric values (∼1.7 µatm yr−1) over 30 years. By contrast, values on inshore reefs have increased at 2.5 to 3 times higher rates. Thus, pCO2 levels on inshore reefs have disproportionately increased compared to atmospheric levels. Our study suggests that inshore GBR reefs are more vulnerable to OA and have less buffering capacity compared to offshore reefs. This may be caused by anthropogenically induced trophic changes in the water column and benthos of inshore reefs subjected to land runoff. PMID:25295864

  14. Destruction of corals and other reef animals by coral spawn slicks on Ningaloo Reef, Western Australia

    Science.gov (United States)

    Simpson, C. J.; Cary, J. L.; Masini, R. J.

    1993-11-01

    In March 1989, most of the corals near Coral Bay, off the north-western coastline of Australia, spawned several nights earlier than usual. Flood, rather than ebb, tides at the time of spawning combined with light north-west winds and low swell conditions to restrict the dispersal of coral propagules and, as a result, large amounts of coral spawn were trapped in the bay, forming extensive slicks. Fish and other animals began to die almost immediately, and over the next few days, over 1 million fish, representing at least 80 species, were washed ashore. A survey of the benthic communities revealed extensive mortality of corals and other reef animals over an area of about 3 km2. Live coral cover in this area decreased from 42.9% to 9.4% and several large coral colonies up to 10 m in diameter were killed. The observed mortality was presumably the result of hypoxia (oxygen depletion) created initially by the respiratory demand of the coral spawn and maintained by the biological oxygen demand of the decomposing spawn slicks and dead animals. Anecdotal reports of corals and other reef animals dying in the vicinity of coral spawn slicks on other reefs in Western Australia suggest that this phenomenon may be a relatively common event on shallow coral reefs where coral mass spawning occurs. These records and observations document, for the first time, a new source of natural disturbance that has a significant influence on the community structure of some coral reefs.

  15. EPA Field Manual for Coral Reef Assessments

    Science.gov (United States)

    The Water Quality Research Program (WQRP) supports development of coral reef biological criteria. Research is focused on developing methods and tools to support implementation of legally defensible biological standards for maintaining biological integrity, which is protected by ...

  16. 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...

  17. 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...

  18. EPA Field Manual for Coral Reef Assessments

    Science.gov (United States)

    The Water Quality Research Program (WQRP) supports development of coral reef biological criteria. Research is focused on developing methods and tools to support implementation of legally defensible biological standards for maintaining biological integrity, which is protected by ...

  19. Ecosystem function and biodiversity on coral reefs

    OpenAIRE

    1994-01-01

    The article highlights a workshop held in Key West, Florida in November 1993 attended by a group of 35 international scientists where topics of ecosystem function and biodiversity on coral reefs were discussed.

  20. 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...

  1. Black reefs: iron-induced phase shifts on coral reefs

    NARCIS (Netherlands)

    Wegley Kelly, L.; Barott, K.L.; Dinsdale, E.; Friedlander, A.M.; Nosrat, B.; Obura, D.; Sala, E.; Sandin, S.A.; Smith, J.E.; Vermeij, M.J.A.; Williams, G.J.; Willner, D.; Rohwer, F.

    2012-01-01

    The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the s

  2. Black reefs: iron-induced phase shifts on coral reefs

    NARCIS (Netherlands)

    Wegley Kelly, L.; Barott, K.L.; Dinsdale, E.; Friedlander, A.M.; Nosrat, B.; Obura, D.; Sala, E.; Sandin, S.A.; Smith, J.E.; Vermeij, M.J.A.; Williams, G.J.; Willner, D.; Rohwer, F.

    2012-01-01

    The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the

  3. Clues to Coral Reef Ecosystem Health: Spectral Analysis Coupled with Radiative Transfer Modeling

    Science.gov (United States)

    Guild, L.; Ganapol, B.; Kramer, P.; Armstrong, R.; Gleason, A.; Torres, J.; Johnson, L.; Garfield, N.

    2003-12-01

    Coral reefs are among the world's most productive and biologically rich ecosystems and are some of the oldest ecosystems on Earth. Coralline structures protect coastlines from storms, maintain high diversity of marine life, and provide nurseries for marine species. Coral reefs play a role in carbon cycling through high rates of organic carbon metabolism and calcification. Coral reefs provide fisheries habitat that are the sole protein source for humans on remote islands. Reefs respond immediately to environmental change and therefore are considered "canaries" of the oceans. However, the world's reefs are in peril: they have shrunk 10-50% from their historical extent due to climate change and anthropogenic activity. An important contribution to coral reef research is improved spectral distinction of reef species' health where anthropogenic activity and climate change impacts are high. Relatively little is known concerning the spectral properties of coral or how coral structures reflect and transmit light. New insights into optical processes of corals under stressed conditions can lead to improved interpretation of airborne and satellite data and forecasting of immediate or long-term impacts of events such as bleaching and disease in coral. We are investigating the spatial and spectral resolution required to detect remotely changes in reef health by coupling spectral analysis of in situ spectra and airborne spectral data with a new radiative transfer model called CorMOD2. Challenges include light attenuation by the water column, atmospheric scattering, and scattering caused by the coral themselves that confound the spectral signal. In CorMOD2, input coral reflectance measurements produce modeled absorption through an inversion at each visible wavelength. The first model development phase of CorMOD2 imposes a scattering baseline that is constant regardless of coral condition, and further specifies that coral is optically thick. Evolution of CorMOD2 is towards a coral

  4. Detecting age-structured effects in growth performance of coral reef fish juveniles

    OpenAIRE

    Mellin, Camille; Galzin, R.; Ponton, Dominique; Vigliola, Laurent

    2009-01-01

    The growth performance of coral reef fish juveniles collected in different habitats is often used as a proxy for habitat quality for juveniles. However, back-calculated growth trajectories of juveniles may be age-structured, for instance, because of potential differences in initial offspring size and/or quality or size-selective mortality. A novel approach is proposed to isolate growth performance of coral reef fish juveniles from potential age-based factors. Juveniles of Chromis viridis (Pom...

  5. Degradation and recovery of Caribbean coral reefs

    OpenAIRE

    Paredes, Gustavo Adolfo

    2009-01-01

    Coral reef ecosystems worldwide have been seriously impacted by human activities. The current deteriorated state of coral reef communities is the result of a long history of exploitation. The scientific community has recognized the extent of degradation, its consequences, and how little we have done to avoid further degradation only in the last two decades. Marine reserves are one of the main conservation actions that could help to reduce the impacts of human activities on the ecosystem, part...

  6. 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...

  7. Single-beam acoustic seabed classification in coral reef environments with application to the assessment of grouper and snapper habitat in the upper Florida Keys, USA

    Science.gov (United States)

    Gleason, Arthur C. R.

    A single-beam acoustic seabed classification system was used to map coral reef environments in the upper Florida Keys, USA, and the Bahamas. The system consisted of two components, both produced by the Quester Tangent Corporation. A QTCView Series V, operating with a 50 kHz sounder, was used for data acquisition, and IMPACT software was used for data processing and classification. First, methodological aspects of system performance were evaluated. Second, the system was applied to the assessment of grouper and snapper habitat. Two methodological properties were explored: transferability (i.e. mapping the same classes at multiple sites) and reproducibility (i.e. surveying one site multiple times). The transferability results showed that a two-class scheme of hard bottom and sediment could be mapped at four sites with overall accuracy ranging from 73% to 86%. The locations of most misclassified echoes had one of two characteristics: a thin sediment veneer overlying hard bottom or within-footprint relief on the order of 0.5 m or greater. Reproducibility experiments showed that consistency of acoustic classes between repeat transects over the same area on different days varied, for the most part, between 50% and 65%. Consistency increased to between 78% and 92% when clustering was limited to two acoustic classes, to between approximately 70% and 100% when only echoes acquired within two degrees of nadir in the pitch direction were used, and to between 81% and 87% when a limited set of features was used for classification. The assessment of grouper and snapper habitat addressed the question whether areas of high fish abundance were associated with characteristic acoustic or geomorphological signatures. The results showed, first, that the hard bottom/sediment classification scheme was a useful first step for stratifying survey areas to increase efficiency of grouper census efforts. Second, an index of acoustic variability complemented the hard bottom

  8. Mapping of coral reefs using the combined bathymetric lidar and CASI datasets (Conference Presentation)

    Science.gov (United States)

    Cruz, Charmaine A.; Tamondong, Ayin M.; Go, Gay A.

    2016-10-01

    Mapping of coral reefs provides information to support the conservation and monitoring of this vulnerable benthic habitat. Coral reef environment has a high level of complexity and spatial heterogeneity, however, typical maps derived using remote sensing data only includes classification of benthic communities. The study aims to update the status of coral reef classification through the advancement of remote sensing technology in the Philippines. This shows the coral community condition in the area. With the use of hyperspectral Compact Airborne Spectrographic Imager (CASI) and bathymetric LiDAR, data were acquired in Apo Reef, Province of Mindoro. Apo Reef is known as the second largest contiguous coral reef in the world. The image taken has a spatial resolution of 0.5 meters with spectral resolution of approximately 10nm between 385nm to 1047nm wavelength regions. Pre-processing of LiDAR data includes extraction of surface bottom and generating derivatives such as Digital Surface Model (DSM), Digital Terrain Model (DTM), rugosity, and slope. Data on spectral reflectance of coral reef types and other substrates, bathymetry, validation points and geotagged underwater video were gathered in situ simultaneous with the image acquisition. Derivative analysis is then applied to the field spectra to determine the wavelength bands for discriminating coral reef types. The optimal subset bands and LiDAR derivatives were used in classifying coral reef types using the supervised classification. Geotagged photos and sampling points were used to validate and assess the accuracy of the map.

  9. Black reefs: iron-induced phase shifts on coral reefs.

    Science.gov (United States)

    Kelly, Linda Wegley; Barott, Katie L; Dinsdale, Elizabeth; Friedlander, Alan M; Nosrat, Bahador; Obura, David; Sala, Enric; Sandin, Stuart A; Smith, Jennifer E; Vermeij, Mark J A; Williams, Gareth J; Willner, Dana; Rohwer, Forest

    2012-03-01

    The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the shipwreck debris are characterized by high benthic cover of turf algae, macroalgae, cyanobacterial mats and corallimorphs, as well as particulate-laden, cloudy water. These sites also have very low coral and crustose coralline algal cover and are call black reefs because of the dark-colored benthic community and reduced clarity of the overlying water column. Here we use a combination of benthic surveys, chemistry, metagenomics and microcosms to investigate if and how shipwrecks initiate and maintain black reefs. Comparative surveys show that the live coral cover was reduced from 40 to 60% to reefs on Millennium, Tabuaeran and Kingman. These three sites are relatively large (>0.75 km(2)). The phase shift occurs rapidly; the Kingman black reef formed within 3 years of the ship grounding. Iron concentrations in algae tissue from the Millennium black reef site were six times higher than in algae collected from reference sites. Metagenomic sequencing of the Millennium Atoll black reef-associated microbial community was enriched in iron-associated virulence genes and known pathogens. Microcosm experiments showed that corals were killed by black reef rubble through microbial activity. Together these results demonstrate that shipwrecks and their associated iron pose significant threats to coral reefs in iron-limited regions.

  10. Patterns in the distribution of coral communities across the central Great Barrier Reef

    Science.gov (United States)

    Done, T. J.

    1982-10-01

    Despite the pre-eminence of the Great Barrier Reef, there has been little systematic description of its biotic communities, and in particular, of the corals themselves. Only recently have the problems of coral taxonomy been sufficiently resolved to allow a beginning to be made in rectifying this deficiency. The present study describes seventeen assemblages of corals which occupy the major habitat types found in and near the central Great Barrier Reef. The habitats studied range from the wave swept reef flats of Coral Sea atolls to the slopes of small reefs occupying sheltered, muddy conditions near the coast. These, and the array of reefs between, have characteristic suites of coral communities which provide the basis for a classification of reefs into non- Acropora reefs and various Acropora reefs. It is speculated that the faunistic differences are maintained because reefs are primarily self-seeded and because the majority of larvae from external sources are of species which are already present. The greatest diversity of both species and community types was found on reefs near the middle of the continental shelf, while the oceanic atolls and nearshore silt-affected reefs are almost equally depauperate.

  11. 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

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

    Science.gov (United States)

    Velásquez, Johanna; Sánchez, Juan A

    2015-01-01

    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 diversity

  13. Coral diseases and bleaching on Colombian Caribbean coral reefs.

    Science.gov (United States)

    Navas-Camacho, Raúl; Gil-Agudelo, Diego Luis; Rodríguez-Ramírez, Alberto; Reyes-Nivia, María Catalina; Garzón-Ferreira, Jaime

    2010-05-01

    Since 1998 the National Monitoring System for the Coral Reefs of Colombia (SIMAC) has monitored the occurrence of coral bleaching and diseases in some Colombian coral reefs (permanent stations at San Andres Island, Rosario Islands, Tayrona, San Bernardo Islands and Urabá). The main purpose is to evaluate their health status and to understand the factors that have been contributing to their decline. To estimate these occurrences, annual surveys in 126 permanent belt transects (10 x 2m) with different depth intervals (3-6 meters, 9-12 meters and 15-18 meters) are performed at all reef sites. Data from the 1998-2004 period, revealed that San Andrés Island had many colonies with diseases (38.9 colonies/m2), and Urabá had high numbers with bleaching (54.4 colonies/m2). Of the seven reported coral diseases studied, Dark Spots Disease (DSD), and White Plague Disease (WPD) were noteworthy because they occurred in all Caribbean monitored sites, and because of their high interannual infection incidence. Thirty five species of scleractinian corals were affected by at least one disease and a high incidence of coral diseases on the main reef builders is documented. Bleaching was present in 34 species. During the whole monitoring period, Agaricia agaricites and Siderastrea siderea were the species most severely affected by DSD and bleaching, respectively. Diseases on species such as Agaricia fragilis, A. grahamae, A. humilis, Diploria clivosa, Eusmilia fastigiata, Millepora complanata, and Mycetophyllia aliciae are recorded for first time in Colombia. We present bleaching and disease incidences, kinds of diseases, coral species affected, reef localities studied, depth intervals of surveys, and temporal (years) variation for each geographic area. This variation makes difficult to clearly determine defined patterns or general trends for monitored reefs. This is the first long-term study of coral diseases and bleaching in the Southwestern Caribbean, and one of the few long

  14. 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.

  15. 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.

  16. 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. © 2015 John Wiley & Sons Ltd.

  17. The engine of the reef: Photobiology of the coral-algal symbiosis

    OpenAIRE

    Melissa Susan Roth

    2014-01-01

    Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology, and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs...

  18. 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 (fisheries.

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

    NARCIS (Netherlands)

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

    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,

  20. Calibration of Community-based Coral Reef Monitoring Protocols ...

    African Journals Online (AJOL)

    Keywords: coral reef monitoring, community-based, calibration. Abstract—Coral reef monitoring (CRM) has been recognised as an important management tool and has ..... Pollution Bulletin 40: 537-550. Wilkinson, C., Green, A., Almany, J. &.

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

    NARCIS (Netherlands)

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

    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

  2. Zonation of uplifted pleistocene coral reefs on barbados, west indies.

    Science.gov (United States)

    Mesolella, K J

    1967-05-05

    The coral species composition of uplifted Pleistocene reefs on Barbados is very similar to Recent West Indian reefs. Acropora palmata, Acropora cervicornis, and Montastrea annularis are qtuantitatively the most important of the coral species.

  3. Genetic divergence across habitats in the widespread coral Seriatopora hystrix and its associated Symbiodinium.

    Directory of Open Access Journals (Sweden)

    Pim Bongaerts

    Full Text Available BACKGROUND: Coral reefs are hotspots of biodiversity, yet processes of diversification in these ecosystems are poorly understood. The environmental heterogeneity of coral reef environments could be an important contributor to diversification, however, evidence supporting ecological speciation in corals is sparse. Here, we present data from a widespread coral species that reveals a strong association of host and symbiont lineages with specific habitats, consistent with distinct, sympatric gene pools that are maintained through ecologically-based selection. METHODOLOGY/PRINCIPAL FINDINGS: Populations of a common brooding coral, Seriatopora hystrix, were sampled from three adjacent reef habitats (spanning a approximately 30 m depth range at three locations on the Great Barrier Reef (n = 336. The populations were assessed for genetic structure using a combination of mitochondrial (putative control region and nuclear (three microsatellites markers for the coral host, and the ITS2 region of the ribosomal DNA for the algal symbionts (Symbiodinium. Our results show concordant genetic partitioning of both the coral host and its symbionts across the different habitats, independent of sampling location. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that coral populations and their associated symbionts can be highly structured across habitats on a single reef. Coral populations from adjacent habitats were found to be genetically isolated from each other, whereas genetic similarity was maintained across similar habitat types at different locations. The most parsimonious explanation for the observed genetic partitioning across habitats is that adaptation to the local environment has caused ecological divergence of distinct genetic groups within S. hystrix.

  4. New protection initiatives announced for coral reefs

    Science.gov (United States)

    Showstack, Randy

    Off the coasts of some of the South Pacific's most idyllic-sounding atolls, Austin Bowden-Kerby has seen first-hand the heavy damage to coral reefs from dynamite and cyanide fishing. For instance, while snorkeling near Chuuk, an island in Micronesia, he has observed craters and rubble beds of coral, which locals have told him date to World War II ordnance.A marine biologist and project scientist for the Coral Gardens Initiative of the Foundation for the Peoples of the South Pacific, Bowden-Kerby has also identified what he says are some public health effects related to destroyed coral reefs and their dying fisheries. These problems include protein and vitamin A deficiency and blindness, all of which may—in some instances—be linked to poor nutrition resulting from lower reef fish consumption by islanders, according to Bowden-Kerby.

  5. Resetting predator baselines in coral reef ecosystems

    Science.gov (United States)

    Bradley, Darcy; Conklin, Eric; Papastamatiou, Yannis P.; McCauley, Douglas J.; Pollock, Kydd; Pollock, Amanda; Kendall, Bruce E.; Gaines, Steven D.; Caselle, Jennifer E.

    2017-01-01

    What did coral reef ecosystems look like before human impacts became pervasive? Early efforts to reconstruct baselines resulted in the controversial suggestion that pristine coral reefs have inverted trophic pyramids, with disproportionally large top predator biomass. The validity of the coral reef inverted trophic pyramid has been questioned, but until now, was not resolved empirically. We use data from an eight-year tag-recapture program with spatially explicit, capture-recapture models to re-examine the population size and density of a key top predator at Palmyra atoll, the same location that inspired the idea of inverted trophic biomass pyramids in coral reef ecosystems. Given that animal movement is suspected to have significantly biased early biomass estimates of highly mobile top predators, we focused our reassessment on the most mobile and most abundant predator at Palmyra, the grey reef shark (Carcharhinus amblyrhynchos). We estimated a density of 21.3 (95% CI 17.8, 24.7) grey reef sharks/km2, which is an order of magnitude lower than the estimates that suggested an inverted trophic pyramid. Our results indicate that the trophic structure of an unexploited reef fish community is not inverted, and that even healthy top predator populations may be considerably smaller, and more precarious, than previously thought. PMID:28220895

  6. 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.

  7. Spatial and temporal variations in coral growth on an inshore turbid reef subjected to multiple disturbances.

    Science.gov (United States)

    Browne, N K

    2012-06-01

    Coral growth rates (linear extension, density, calcification rates) of three fast-growing corals (Acropora, Montipora, Turbinaria) were studied in situ on Middle Reef, an inshore reef located on the central Great Barrier Reef (GBR), to assess the influence of changing environmental conditions on coral condition and reef growth. Middle Reef is subjected to both local (e.g. high sediment loads) and global (e.g. coral bleaching) disturbance events, usually associated with reduced coral growth. Results indicated, however, that Acropora growth rates (mean linear extension = 6.3 cm/year) were comparable to those measured at similar depths on offshore reefs on the GBR. Montipora linear extension (2.9 cm/year) was greater than estimates available from both clear-water and turbid reefs, and Turbinaria's dense skeleton (1.3 g/cm(3)) may be more resilient to physical damage as ocean pH falls. Coral growth was found to vary between reef habitats due to spatial differences in water motion and sediment dynamics, and temporally with lower calcification rates during the summer months when SSTs (monthly average 29 °C) and rainfall (monthly total >500 mm) were high. In summary, corals on Middle Reef are robust and resilient to their marginal environmental conditions, but are susceptible to anthropogenic disturbances during the summer months.

  8. The functional importance of Acropora austera as nursery areas for juvenile reef fish on South African coral reefs

    Science.gov (United States)

    Floros, C.; Schleyer, M. H.

    2017-03-01

    Many coral reef fish species use mangrove and seagrass beds as nursery areas. However, in certain regions, the absence or scarcity of such habitats suggests that juvenile coral reef fish may be seeking refuge elsewhere. The underlying biogenic substratum of most coral reefs is structurally complex and provides many types of refuge. However, on young or subtropical coral reefs, species may be more reliant on the living coral layer as nursery areas. Such is the case on the high-latitude coral reefs of South Africa where the coral communities consist of a thin veneer of coral overlaying late Pleistocene bedrock. Thus, the morphology of coral species may be a major determinant in the availability of refuge space. Acropora austera is a branching species that forms large patches with high structural complexity. Associated with these patches is a diverse community of fish species, particularly juveniles. Over the past decade, several large (>100 m2) A. austera patches at Sodwana Bay have been diminishing for unknown reasons and there is little evidence of their replacement or regrowth. Seven patches of A. austera (AP) and non- A. austera (NAP) were selected and monitored for 12 months using visual surveys to investigate the importance of AP as refugia and nursery areas. There were significant differences in fish communities between AP and NAP habitats. In total, 110 species were recorded within the patches compared to 101 species outside the patches. Labrids and pomacentrids were the dominant species in the AP habitats, while juvenile scarids, acanthurids, chaetodons and serranids were also abundant. The diversity and abundance of fish species increased significantly with AP size. As the most structurally complex coral species on the reefs, the loss of APs may have significant implications for the recruitment and survival of certain fish species.

  9. 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

    invertebrate feeders. To our knowledge, the present study provides the first evidence that through habitat competition, the presence of S. fuscus may affect reef fish communities associated with M. alcicornis coral colonies. Our findings also indicate that S. fuscus uses M. alcicornis coral colonies as part of their territory for shelter and foraging. In conclusion, M. alcicornis fire-coral colonies are extremely important habitats for reef fishes and the size and presence of a territorial damselfish are relevant variables for associated reef fish community. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Developing a multi-stressor gradient for coral reefs

    Science.gov (United States)

    Coral reefs are often found near coastal waters where multiple anthropogenic stressors co-occur at areas of human disturbance. Developing coral reef biocriteria under the U.S. Clean Water Act requires relationships between anthropogenic stressors and coral reef condition to be es...

  11. Developing a multi-stressor gradient for coral reefs

    Science.gov (United States)

    Coral reefs are often found near coastal waters where multiple anthropogenic stressors co-occur at areas of human disturbance. Developing coral reef biocriteria under the U.S. Clean Water Act requires relationships between anthropogenic stressors and coral reef condition to be es...

  12. Measuring coral reef community metabolism using new benthic chamber technology

    Science.gov (United States)

    Yates, K.K.; Halley, R.B.

    2003-01-01

    Accurate measurement of coral reef community metabolism is a necessity for process monitoring and in situ experimentation on coral reef health. Traditional methodologies used for these measurements are effective but limited by location and scale constraints. We present field trial results for a new benthic chamber system called the Submersible Habitat for Analyzing Reef Quality (SHARQ). This large, portable incubation system enables in situ measurement and experimentation on community- scale metabolism. Rates of photosynthesis, respiration, and calcification were measured using the SHARQ for a variety of coral reef substrate types on the reef flat of South Molokai, Hawaii, and in Biscayne National Park, Florida. Values for daily gross production, 24-h respiration, and net calcification ranged from 0.26 to 6.45 g O2 m-2 day-1, 1.96 to 8.10 g O2 m-2 24 h-1, and 0.02 to 2.0 g CaCO3 m -2 day-1, respectively, for all substrate types. Field trials indicate that the SHARQ incubation chamber is an effective tool for in situ isolation of a water mass over a variety of benthic substrate types for process monitoring, experimentation, and other applications.

  13. Community change within a Caribbean coral reef Marine Protected Area following two decades of local management.

    Directory of Open Access Journals (Sweden)

    Mae M Noble

    Full Text Available Structural change in both the habitat and reef-associated fish assemblages within spatially managed coral reefs can provide key insights into the benefits and limitations of Marine Protected Areas (MPAs. While MPA zoning effects on particular target species are well reported, we are yet to fully resolve the various affects of spatial management on the structure of coral reef communities over decadal time scales. Here, we document mixed affects of MPA zoning on fish density, biomass and species richness over the 21 years since establishment of the Saba Marine Park (SMP. Although we found significantly greater biomass and species richness of reef-associated fishes within shallow habitats (5 meters depth closed to fishing, this did not hold for deeper (15 m habitats, and there was a widespread decline (38% decrease in live hard coral cover and a 68% loss of carnivorous reef fishes across all zones of the SMP from the 1990s to 2008. Given the importance of live coral for the maintenance and replenishment of reef fishes, and the likely role of chronic disturbance in driving coral decline across the region, we explore how local spatial management can help protect coral reef ecosystems within the context of large-scale environmental pressures and disturbances outside the purview of local MPA management.

  14. Community change within a Caribbean coral reef Marine Protected Area following two decades of local management.

    Science.gov (United States)

    Noble, Mae M; van Laake, Gregoor; Berumen, Michael L; Fulton, Christopher J

    2013-01-01

    Structural change in both the habitat and reef-associated fish assemblages within spatially managed coral reefs can provide key insights into the benefits and limitations of Marine Protected Areas (MPAs). While MPA zoning effects on particular target species are well reported, we are yet to fully resolve the various affects of spatial management on the structure of coral reef communities over decadal time scales. Here, we document mixed affects of MPA zoning on fish density, biomass and species richness over the 21 years since establishment of the Saba Marine Park (SMP). Although we found significantly greater biomass and species richness of reef-associated fishes within shallow habitats (5 meters depth) closed to fishing, this did not hold for deeper (15 m) habitats, and there was a widespread decline (38% decrease) in live hard coral cover and a 68% loss of carnivorous reef fishes across all zones of the SMP from the 1990s to 2008. Given the importance of live coral for the maintenance and replenishment of reef fishes, and the likely role of chronic disturbance in driving coral decline across the region, we explore how local spatial management can help protect coral reef ecosystems within the context of large-scale environmental pressures and disturbances outside the purview of local MPA management.

  15. Community Change within a Caribbean Coral Reef Marine Protected Area following Two Decades of Local Management

    KAUST Repository

    Noble, Mae M.

    2013-01-14

    Structural change in both the habitat and reef-associated fish assemblages within spatially managed coral reefs can provide key insights into the benefits and limitations of Marine Protected Areas (MPAs). While MPA zoning effects on particular target species are well reported, we are yet to fully resolve the various affects of spatial management on the structure of coral reef communities over decadal time scales. Here, we document mixed affects of MPA zoning on fish density, biomass and species richness over the 21 years since establishment of the Saba Marine Park (SMP). Although we found significantly greater biomass and species richness of reef-associated fishes within shallow habitats (5 meters depth) closed to fishing, this did not hold for deeper (15 m) habitats, and there was a widespread decline (38% decrease) in live hard coral cover and a 68% loss of carnivorous reef fishes across all zones of the SMP from the 1990s to 2008. Given the importance of live coral for the maintenance and replenishment of reef fishes, and the likely role of chronic disturbance in driving coral decline across the region, we explore how local spatial management can help protect coral reef ecosystems within the context of large-scale environmental pressures and disturbances outside the purview of local MPA management. © 2013 Noble et al.

  16. 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.

  17. Herbivory, connectivity, and ecosystem resilience: response of a coral reef to a large-scale perturbation.

    Directory of Open Access Journals (Sweden)

    Thomas C Adam

    Full Text Available Coral reefs world-wide are threatened by escalating local and global impacts, and some impacted reefs have shifted from coral dominance to a state dominated by macroalgae. Therefore, there is a growing need to understand the processes that affect the capacity of these ecosystems to return to coral dominance following disturbances, including those that prevent the establishment of persistent stands of macroalgae. Unlike many reefs in the Caribbean, over the last several decades, reefs around the Indo-Pacific island of Moorea, French Polynesia have consistently returned to coral dominance following major perturbations without shifting to a macroalgae-dominated state. Here, we present evidence of a rapid increase in populations of herbivorous fishes following the most recent perturbation, and show that grazing by these herbivores has prevented the establishment of macroalgae following near complete loss of coral on offshore reefs. Importantly, we found the positive response of herbivorous fishes to increased benthic primary productivity associated with coral loss was driven largely by parrotfishes that initially recruit to stable nursery habitat within the lagoons before moving to offshore reefs later in life. These results underscore the importance of connectivity between the lagoon and offshore reefs for preventing the establishment of macroalgae following disturbances, and indicate that protecting nearshore nursery habitat of herbivorous fishes is critical for maintaining reef resilience.

  18. Herbivory, connectivity, and ecosystem resilience: response of a coral reef to a large-scale perturbation.

    Science.gov (United States)

    Adam, Thomas C; Schmitt, Russell J; Holbrook, Sally J; Brooks, Andrew J; Edmunds, Peter J; Carpenter, Robert C; Bernardi, Giacomo

    2011-01-01

    Coral reefs world-wide are threatened by escalating local and global impacts, and some impacted reefs have shifted from coral dominance to a state dominated by macroalgae. Therefore, there is a growing need to understand the processes that affect the capacity of these ecosystems to return to coral dominance following disturbances, including those that prevent the establishment of persistent stands of macroalgae. Unlike many reefs in the Caribbean, over the last several decades, reefs around the Indo-Pacific island of Moorea, French Polynesia have consistently returned to coral dominance following major perturbations without shifting to a macroalgae-dominated state. Here, we present evidence of a rapid increase in populations of herbivorous fishes following the most recent perturbation, and show that grazing by these herbivores has prevented the establishment of macroalgae following near complete loss of coral on offshore reefs. Importantly, we found the positive response of herbivorous fishes to increased benthic primary productivity associated with coral loss was driven largely by parrotfishes that initially recruit to stable nursery habitat within the lagoons before moving to offshore reefs later in life. These results underscore the importance of connectivity between the lagoon and offshore reefs for preventing the establishment of macroalgae following disturbances, and indicate that protecting nearshore nursery habitat of herbivorous fishes is critical for maintaining reef resilience.

  19. Fish Community Characterization on Shallow (less than 30m) Hardbottom Shelf Habitats in St. Croix, USVI. A preliminary field survey to assess operational and logistical approaches to implement the National Coral Reef Monitoring Program (NCRMP) in the USVI.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reef fish populations are a conspicuous and essential component of USVI coral reef ecosystems. Yet despite their importance, striking population and community level...

  20. Benthic Community Characterization on Shallow (less than 30m) Hardbottom Shelf Habitats in St. Croix, USVI. A preliminary field survey to assess operational and logistical approaches to implement the National Coral Reef Monitoring Program (NCRMP) in the USVI.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reef fish populations are a conspicuous and essential component of USVI coral reef ecosystems. Yet despite their importance, striking population and community level...

  1. Fish Community Characterization on Shallow (<30m) Hardbottom Shelf Habitats in St. Croix, USVI. A preliminary field survey to assess operational and logistical approaches to implement the National Coral Reef Monitoring Program (NCRMP) in the USVI. (NODC Accession 0125237)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reef fish populations are a conspicuous and essential component of USVI coral reef ecosystems. Yet despite their importance, striking population and community level...

  2. Benthic Community Characterization on Shallow (<30m) Hardbottom Shelf Habitats in St. Croix, USVI. A preliminary field survey to assess operational and logistical approaches to implement the National Coral Reef Monitoring Program (NCRMP) in the USVI. (NODC Accession 0125237)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reef fish populations are a conspicuous and essential component of USVI coral reef ecosystems. Yet despite their importance, striking population and community level...

  3. 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

  4. 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.

  5. Multisensor and multitemporal data from Landsat images to detect damage to coral reefs, small islands in the Spermonde archipelago, Indonesia

    Science.gov (United States)

    Nurdin, Nurjannah; Komatsu, Teruhisa; Agus; Akbar AS, M.; Djalil, Abdul Rasyid; Amri, Khairul

    2015-06-01

    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 advantages, many factors are threatening coral reefs. The study site was selected in Spermonde archipelago, South Sulawesi, Indonesia because this area is included in the Coral Triangle, recognized as the epicenter of coral diversity and a priority for conservation. Images of Landsat MSS, Landsat TM, Landsat ETM, Landsat ETM+, and Landsat 8 data were used to examine changes in the coral reefs of Suranti Island in the Spermonde Archipelago during forty one years from 1972 to 2013. The image processing includes gap fills, atmospheric corrections, geometric corrections, image composites, water column corrections, unsupervised classifications, and reclassifications. Fill Gap processing was done on Landsat ETM+ SLC-off. Subsequently, a multi-component change detection procedure was applied to define changes. Shallow water bottom types classification was divided into live coral, rubble and sand habitats, dead coral with algae, rubble, and sand. Preliminary results showed significant changes during the period 1972-2013 as well as changes in coral reefs, likely explained partly by destructive fishing practices.

  6. Spatial and seasonal reef calcification in corals and calcareous crusts in the central Red Sea

    Science.gov (United States)

    Roik, Anna; Roder, Cornelia; Röthig, Till; Voolstra, Christian R.

    2016-06-01

    The existence of coral reef ecosystems critically relies on the reef carbonate framework produced by scleractinian corals and calcareous crusts (i.e., crustose coralline algae). While the Red Sea harbors one of the longest connected reef systems in the world, detailed calcification data are only available from the northernmost part. To fill this knowledge gap, we measured in situ calcification rates of primary and secondary reef builders in the central Red Sea. We collected data on the major habitat-forming coral genera Porites, Acropora, and Pocillopora and also on calcareous crusts (CC) in a spatio-seasonal framework. The scope of the study comprised sheltered and exposed sites of three reefs along a cross-shelf gradient and over four seasons of the year. Calcification of all coral genera was consistent across the shelf and highest in spring. In addition, Pocillopora showed increased calcification at exposed reef sites. In contrast, CC calcification increased from nearshore, sheltered to offshore, exposed reef sites, but also varied over seasons. Comparing our data to other reef locations, calcification in the Red Sea was in the range of data collected from reefs in the Caribbean and Indo-Pacific; however, Acropora calcification estimates were at the lower end of worldwide rates. Our study shows that the increasing coral cover from nearshore to offshore environments aligned with CC calcification but not coral calcification, highlighting the potentially important role of CC in structuring reef cover and habitats. While coral calcification maxima have been typically observed during summer in many reef locations worldwide, calcification maxima during spring in the central Red Sea indicate that summer temperatures exceed the optima of reef calcifiers in this region. This study provides a foundation for comparative efforts and sets a baseline to quantify impact of future environmental change in the central Red Sea.

  7. Spatial and seasonal reef calcification in corals and calcareous crusts in the central Red Sea

    KAUST Repository

    Roik, Anna Krystyna

    2015-12-14

    The existence of coral reef ecosystems critically relies on the reef carbonate framework produced by scleractinian corals and calcareous crusts (i.e., crustose coralline algae). While the Red Sea harbors one of the longest connected reef systems in the world, detailed calcification data are only available from the northernmost part. To fill this knowledge gap, we measured in situ calcification rates of primary and secondary reef builders in the central Red Sea. We collected data on the major habitat-forming coral genera Porites, Acropora, and Pocillopora and also on calcareous crusts (CC) in a spatio-seasonal framework. The scope of the study comprised sheltered and exposed sites of three reefs along a cross-shelf gradient and over four seasons of the year. Calcification of all coral genera was consistent across the shelf and highest in spring. In addition, Pocillopora showed increased calcification at exposed reef sites. In contrast, CC calcification increased from nearshore, sheltered to offshore, exposed reef sites, but also varied over seasons. Comparing our data to other reef locations, calcification in the Red Sea was in the range of data collected from reefs in the Caribbean and Indo-Pacific; however, Acropora calcification estimates were at the lower end of worldwide rates. Our study shows that the increasing coral cover from nearshore to offshore environments aligned with CC calcification but not coral calcification, highlighting the potentially important role of CC in structuring reef cover and habitats. While coral calcification maxima have been typically observed during summer in many reef locations worldwide, calcification maxima during spring in the central Red Sea indicate that summer temperatures exceed the optima of reef calcifiers in this region. This study provides a foundation for comparative efforts and sets a baseline to quantify impact of future environmental change in the central Red Sea.

  8. Prehistorical and historical declines in Caribbean coral reef accretion rates driven by loss of parrotfish

    Science.gov (United States)

    Cramer, Katie L.; O'Dea, Aaron; Clark, Tara R.; Zhao, Jian-Xin; Norris, Richard D.

    2017-01-01

    Caribbean coral reefs have transformed into algal-dominated habitats over recent decades, but the mechanisms of change are unresolved due to a lack of quantitative ecological data before large-scale human impacts. To understand the role of reduced herbivory in recent coral declines, we produce a high-resolution 3,000 year record of reef accretion rate and herbivore (parrotfish and urchin) abundance from the analysis of sediments and fish, coral and urchin subfossils within cores from Caribbean Panama. At each site, declines in accretion rates and parrotfish abundance were initiated in the prehistorical or historical period. Statistical tests of direct cause and effect relationships using convergent cross mapping reveal that accretion rates are driven by parrotfish abundance (but not vice versa) but are not affected by total urchin abundance. These results confirm the critical role of parrotfish in maintaining coral-dominated reef habitat and the urgent need for restoration of parrotfish populations to enable reef persistence.

  9. Coupled dynamics of territorial damselfishes and juvenile corals on the reef crest

    Science.gov (United States)

    Casey, J. M.; Choat, J. H.; Connolly, S. R.

    2015-03-01

    Territories of grazing fishes in the family Pomacentridae have been documented to cover a substantial proportion of shallow, exposed coral reef fronts, and these fishes can have profound effects on benthic community composition, including the recruitment and post-settlement survival of scleractinian corals. However, current studies of territorial grazer effects on corals have focused on back-reef habitats. Territorial damselfishes occur in distinct behavioural guilds ranging from indeterminate territorial grazers with thin algal turfs and low rates of territorial aggression to intensive territorial grazers with thick turfs and high rates of aggression. To determine the impact of territorial grazers on the establishment of juvenile corals, we surveyed the reef crest habitat of Lizard Island, Great Barrier Reef, using fixed transects to assess the effects of indeterminate and intensive territorial grazers on juvenile coral abundance and taxonomic composition. In addition, the turnover of territorial pomacentrids was monitored as well as the effects of turnover on juvenile coral assemblages. Intensive territorial grazers were associated with a significantly lower juvenile coral abundance (34 % decrease), but neither intensive nor indeterminate grazer territories impacted juvenile coral taxonomic composition. Over the course of 1 yr, there was a high rate of territorial turnover (39.7 %). Turnover from control plots to intensive damselfish territories was accompanied by a 44 % decrease in juvenile corals; conversely, turnover from intensive damselfish territories to control plots coincided with a 48 % increase in juvenile corals. These findings reveal two main conclusions. Firstly, the association between damselfish territories and the abundance and spatial turnover of juvenile corals strongly implies that territorial grazers have a negative effect on juvenile coral populations. Secondly, the unexpectedly high temporal turnover of damselfish territories indicates that

  10. The role of deep reefs in shallow reef recovery: an assessment of vertical connectivity in a brooding coral from west and east Australia.

    Science.gov (United States)

    van Oppen, Madeleine J H; Bongaerts, Pim; Underwood, Jim N; Peplow, Lesa M; Cooper, Timothy F

    2011-04-01

    Approximately one quarter of zooxanthellate coral species have a depth distribution from shallow waters (coral bleaching. This has led to the hypothesis that deep populations may serve as refuges and a source of recruits for shallow reef habitats. The extent of vertical connectivity of reef coral species, however, is largely unquantified. Using 10 coral host microsatellite loci and sequences of the host mtDNA putative control region, as well as ribosomal DNA (rDNA) ITS2 sequences of the coral's algal endosymbionts (Symbiodinium), we examine population structure, connectivity and symbiont specificity in the brooding coral Seriatopora hystrix across a depth profile in both northwest (Scott Reef) and northeast Australia (Yonge Reef). Strong genetic structuring over depth was observed in both regions based on the microsatellite loci; however, Yonge Reef exhibited an additional partitioning of mtDNA lineages (associated with specific symbiont ITS2 types), whereas Scott Reef was dominated by a single mtDNA lineage (with no apparent host-symbiont specificity). Evidence for recruitment of larvae of deep water origin into shallow habitats was found at Scott Reef, suggesting that recovery of shallow water habitats may be aided by migration from deep water refuges. Conversely, no migration from the genetically divergent deep slope populations into the shallow habitats was evident at Yonge Reef, making recovery of shallow habitats from deeper waters at this location highly unlikely.

  11. Caribbean-wide decline in carbonate production threatens coral reef growth.

    Science.gov (United States)

    Perry, Chris T; Murphy, Gary N; Kench, Paul S; Smithers, Scott G; Edinger, Evan N; Steneck, Robert S; Mumby, Peter J

    2013-01-01

    Global-scale deteriorations in coral reef health have caused major shifts in species composition. One projected consequence is a lowering of reef carbonate production rates, potentially impairing reef growth, compromising ecosystem functionality and ultimately leading to net reef erosion. Here, using measures of gross and net carbonate production and erosion from 19 Caribbean reefs, we show that contemporary carbonate production rates are now substantially below historical (mid- to late-Holocene) values. On average, current production rates are reduced by at least 50%, and 37% of surveyed sites were net erosional. Calculated accretion rates (mm year(-1)) for shallow fore-reef habitats are also close to an order of magnitude lower than Holocene averages. A live coral cover threshold of ~10% appears critical to maintaining positive production states. Below this ecological threshold carbonate budgets typically become net negative and threaten reef accretion. Collectively, these data suggest that recent ecological declines are now suppressing Caribbean reef growth potential.

  12. Reef fishes of Saba Bank, Netherlands Antilles: assemblage structure across a gradient of habitat types.

    Directory of Open Access Journals (Sweden)

    Wes Toller

    Full Text Available Saba Bank is a 2,200 km(2 submerged carbonate platform in the northeastern Caribbean Sea off Saba Island, Netherlands Antilles. The presence of reef-like geomorphic features and significant shelf edge coral development on Saba Bank have led to the conclusion that it is an actively growing, though wholly submerged, coral reef atoll. However, little information exists on the composition of benthic communities or associated reef fish assemblages of Saba Bank. We selected a 40 km(2 area of the bank for an exploratory study. Habitat and reef fish assemblages were investigated in five shallow-water benthic habitat types that form a gradient from Saba Bank shelf edge to lagoon. Significant coral cover was restricted to fore reef habitat (average cover 11.5% and outer reef flat habitat (2.4% and declined to near zero in habitats of the central lagoon zone. Macroalgae dominated benthic cover in all habitats (average cover: 32.5--48.1% but dominant algal genera differed among habitats. A total of 97 fish species were recorded. The composition of Saba Bank fish assemblages differed among habitat types. Highest fish density and diversity occurred in the outer reef flat, fore reef and inner reef flat habitats. Biomass estimates for commercially valued species in the reef zone (fore reef and reef flat habitats ranged between 52 and 83 g/m(2. The composition of Saba Bank fish assemblages reflects the absence of important nursery habitats, as well as the effects of past fishing. The relatively high abundance of large predatory fish (i.e. groupers and sharks, which is generally considered an indicator of good ecosystem health for tropical reef systems, shows that an intact trophic network is still present on Saba Bank.

  13. Radiative Transfer Modeling, Spectral Analysis, and Remote Sensing of Coral Reefs

    Science.gov (United States)

    Guild, L.; Ganapol, B.; Furfaro, R.; Kramer, P.; Armstrong, R.; Gleason, A.; Torres, J.

    2004-12-01

    The calcium carbonate structures of tropical coral reefs protect coastlines from storms, create habitats for the world's greatest marine biodiversity, provide nurseries for many marine species; play essential roles in carbon and CO2 cycles, are major protein sources for many local populations, and are vital for sustainable economies of many societies. The world's reefs are in peril due to climate change and anthropogenic activity caused by rapidly growing populations in coastal zones. An important contribution to coral reef research is improved spectral distinction of reef components indicative of reef condition, including physical and biological degradation. Unfortunately, relatively little is known concerning the spectral properties of coral or how coral architecture reflect/transmit light. New insights into optical processes of corals can lead to improved interpretation of remote sensing data and forecasting of immediate or long-term impacts such as bleaching and disease in coral and algal overgrowth. We are investigating the spatial/spectral properties required to remotely sense changes in reef biological and physical properties by coupling spectral analysis of in situ spectra with a new coral-specific radiative transfer model. The first model development phase (CorMOD) imposes a scattering baseline that is constant regardless of coral condition, and further specifies that coral is optically thick. Evolution of the model is towards a coral-specific radiative transfer model that includes coral biochemical concentrations, specific absorptivities of coral components, and transmission measurements from coral surfaces. We present our field collected in situ spectra and resultant output relative absorption profiles of coral from CorMOD. Further, we will present NASA AVIRIS data and in situ spectra collection of coral and seagrass to support the AVIRIS mission that was collected during August 2004 for Florida Keys and Puerto Rico.

  14. 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 (study were much lower than data reported from other coral reef systems. In experiments with two Sargassum species tissue P levels were correlated negatively, and N:P ratios were positively correlated with APA. High APA can compensate for a relative P-limitation of macroalgae in coral reef systems that are subject to significant N-inputs, such as the GBR inshore reefs. APA and other mechanisms to acquire a range of nutrient species allow inshore species to thrive in habitats with episodic nutrient supply. These species also are likely to benefit from an increased nutrient supply caused by human activity, which currently is a global problem.

  15. Coral reef soundscapes may not be detectable far from the reef

    Science.gov (United States)

    Kaplan, Maxwell B.; Mooney, T. Aran

    2016-08-01

    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.

  16. Defining critical habitats of threatened and endemic reef fishes with a multivariate approach.

    Science.gov (United States)

    Purcell, Steven W; Clarke, K Robert; Rushworth, Kelvin; Dalton, Steven J

    2014-12-01

    Understanding critical habitats of threatened and endemic animals is essential for mitigating extinction risks, developing recovery plans, and siting reserves, but assessment methods are generally lacking. We evaluated critical habitats of 8 threatened or endemic fish species on coral and rocky reefs of subtropical eastern Australia, by measuring physical and substratum-type variables of habitats at fish sightings. We used nonmetric and metric multidimensional scaling (nMDS, mMDS), Analysis of similarities (ANOSIM), similarity percentages analysis (SIMPER), permutational analysis of multivariate dispersions (PERMDISP), and other multivariate tools to distinguish critical habitats. Niche breadth was widest for 2 endemic wrasses, and reef inclination was important for several species, often found in relatively deep microhabitats. Critical habitats of mainland reef species included small caves or habitat-forming hosts such as gorgonian corals and black coral trees. Hard corals appeared important for reef fishes at Lord Howe Island, and red algae for mainland reef fishes. A wide range of habitat variables are required to assess critical habitats owing to varied affinities of species to different habitat features. We advocate assessments of critical habitats matched to the spatial scale used by the animals and a combination of multivariate methods. Our multivariate approach furnishes a general template for assessing the critical habitats of species, understanding how these vary among species, and determining differences in the degree of habitat specificity. © 2014 Society for Conservation Biology.

  17. Current status of coral reefs in the United Arab Emirates: Distribution, extent, and community structure with implications for management.

    Science.gov (United States)

    Grizzle, Raymond E; Ward, Krystin M; AlShihi, Rashid M S; Burt, John A

    2016-04-30

    Coral reefs of the United Arab Emirates were once extensive, but have declined dramatically in recent decades. Marine management and policy have been hampered by outdated and inaccurate habitat maps and habitat quality information. We combined existing recent datasets with our newly mapped coral habitats to provide a current assessment of nation-wide extent, and performed quantitative surveys of communities at 23 sites to assess coral cover and composition. Over 132 km(2) of coral habitat was mapped, averaging 28.6 ± 3.8% live coral cover at surveyed sites. In the Arabian Gulf low cover, low richness Porites dominated communities characterized western Abu Dhabi, while reefs northeast of Abu Dhabi city generally contained higher richness and cover, and were dominated by merulinids (formerly faviids). Distinct communities occur in the Sea of Oman, where cover and richness were low. We provide management recommendations to enhance conservation of vulnerable coral reefs in the UAE.

  18. The engine of the reef: Photobiology of the coral-algal symbiosis

    Directory of Open Access Journals (Sweden)

    Melissa Susan Roth

    2014-08-01

    Full Text Available Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs, Symbiodinium must safely harvest sunlight for photosynthesis and dissipate excess energy to prevent oxidative stress. Oxidative stress is caused by environmental stressors such as those associated with global climate change, and ultimately leads to breakdown of the coral-algal symbiosis known as coral bleaching. Recently, large-scale coral bleaching events have become pervasive and frequent threatening and endangering coral reefs. Because the coral-algal symbiosis is the biological engine producing the reef, the future of coral reef ecosystems depends on the ecophysiology of the symbiosis. This review examines the photobiology of the coral-algal symbiosis with particular focus on the photophysiological responses and timescales of corals and Symbiodinium. Additionally, this review summarizes the light environment and its dynamics, the vulnerability of the symbiosis to oxidative stress, the abiotic and biotic factors influencing photosynthesis, the diversity of the coral-algal symbiosis and recent advances in the field. Studies integrating physiology with the developing omics fields will provide new insights into the coral-algal symbiosis. Greater physiological and ecological understanding of the coral-algal symbiosis is needed for protection and conservation of coral reefs.

  19. Coral reef surveys in India

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    with those practiced elsewhere. With these objectives, diversification of observations to include various reef responses both at community level and at organism level have just begun and may eventually be continued to integrate with global reef monitoring...

  20. Feedbacks Between Wave Energy And Declining Coral Reef Structure: Implications For Coastal Morphodynamics

    Science.gov (United States)

    Grady, A. E.; Jenkins, C. J.; Moore, L. J.; Potts, D. C.; Burgess, P. M.; Storlazzi, C. D.; Elias, E.; Reidenbach, M. A.

    2013-12-01

    The incident wave energy dissipated by the structural complexity and bottom roughness of coral reef ecosystems, and the carbonate sediment produced by framework-building corals, provide natural shoreline protection and nourishment, respectively. Globally, coral reef ecosystems are in decline as a result of ocean warming and acidification, which is exacerbated by chronic regional stressors such as pollution and disease. As a consequence of declining reef health, many reef ecosystems are experiencing reduced coral cover and shifts to dominance by macroalgae, resulting in a loss of rugosity and thus hydrodynamic roughness. As coral reef architecture is compromised and carbonate skeletons are eroded, wave energy dissipation and sediment transport patterns--along with the carbonate sediment budget of the coastal environment--may be altered. Using a Delft3D numerical model of the south-central Molokai, Hawaii, fringing reef, we simulate the effects of changing reef states on wave energy and sediment transport. To determine the temporally-varying effects of biotic and abiotic stressors such as storms and bleaching on the reef structure and carbonate production, we couple Delft3D with CarboLOT, a model that simulates growth and competition of carbonate-producing organisms. CarboLOT is driven by the Lotka-Volterra population ecology equations and niche suitability principles, and accesses the CarboKB database for region-specific, carbonate-producing species information on growth rates, reproduction patterns, habitat suitability, as well as organism geometries. Simulations assess how changing reef states--which alter carbonate sediment production and reef morphology and thus hydrodynamic roughness--impact wave attenuation and sediment transport gradients along reef-fronted beaches. Initial results suggest that along fringing reefs having characteristics similar to the Molokai fringing reef, projected sea level rise will likely outpace coral reef accretion, and the increased

  1. Experimental evaluation of imprinting and the role innate preference plays in habitat selection in a coral reef fish.

    Science.gov (United States)

    Dixson, Danielle L; Jones, Geoffrey P; Munday, Philip L; Planes, Serge; Pratchett, Morgan S; Thorrold, Simon R

    2014-01-01

    When facing decisions about where to live, juveniles have a strong tendency to choose habitats similar to where their parents successfully bred. Developing larval fishes can imprint on the chemical cues from their natal habitat. However, to demonstrate that imprinting is ecologically important, it must be shown that settlers respond and distinguish among different imprinted cues, and use imprinting for decisions in natural environments. In addition, the potential role innate preferences play compared to imprinted choices also needs to be examined. As environmental variability increases due to anthropogenic causes these two recognition mechanisms, innate and imprinting, could provide conflicting information. Here we used laboratory rearing and chemical choice experiments to test imprinting in larval anemonefish (Amphiprion percula). Individuals exposed to a variety of benthic habitat or novel olfactory cues as larvae either developed a preference for (spent >50% of their time in the cue) or increased their attraction to (increased preference but did not spend >50% of their time in the cue) the cue when re-exposed as settlers. Results indicate not only the capacity for imprinting but also the ability to adjust innate preferences after early exposure to a chemical cue. To test ecological relevance in the natural system, recruits were collected from anemones and related to their parents, using genetic parentage analysis, providing information on the natal anemone species and the species chosen at settlement. Results demonstrated that recruits did not preferentially return to their natal species, conflicting with laboratory results indicating the importance imprinting might have in habitat recognition.

  2. 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…

  3. Habitats as Surrogates of Taxonomic and Functional Fish Assemblages in Coral Reef Ecosystems: A Critical Analysis of Factors Driving Effectiveness

    Science.gov (United States)

    Van Wynsberge, Simon; Andréfouët, Serge; Hamel, Mélanie A.; Kulbicki, Michel

    2012-01-01

    Species check-lists are helpful to establish Marine Protected Areas (MPAs) and protect local richness, endemicity, rarity, and biodiversity in general. However, such exhaustive taxonomic lists (i.e., true surrogate of biodiversity) require extensive and expensive censuses, and the use of estimator surrogates (e.g., habitats) is an appealing alternative. In truth, surrogate effectiveness appears from the literature highly variable both in marine and terrestrial ecosystems, making it difficult to provide practical recommendations for managers. Here, we evaluate how the biodiversity reference data set and its inherent bias can influence effectiveness. Specifically, we defined habitats by geomorphology, rugosity, and benthic cover and architecture criteria, and mapped them with satellite images for a New-Caledonian site. Fish taxonomic and functional lists were elaborated from Underwater Visual Censuses, stratified according to geomorphology and exposure. We then tested if MPA networks designed to maximize habitat richness, diversity and rarity could also effectively maximize fish richness, diversity, and rarity. Effectiveness appeared highly sensitive to the fish census design itself, in relation to the type of habitat map used and the scale of analysis. Spatial distribution of habitats (estimator surrogate’s distribution), quantity and location of fish census stations (target surrogate’s sampling), and random processes in the MPA design all affected effectiveness to the point that one small change in the data set could lead to opposite conclusions. We suggest that previous conclusions on surrogacy effectiveness, either positive or negative, marine or terrestrial, should be considered with caution, except in instances where very dense data sets were used without pseudo-replication. Although this does not rule out the validity of using surrogates of species lists for conservation planning, the critical joint examination of both target and estimator surrogates is

  4. Habitats as surrogates of taxonomic and functional fish assemblages in coral reef ecosystems: a critical analysis of factors driving effectiveness.

    Directory of Open Access Journals (Sweden)

    Simon Van Wynsberge

    Full Text Available Species check-lists are helpful to establish Marine Protected Areas (MPAs and protect local richness, endemicity, rarity, and biodiversity in general. However, such exhaustive taxonomic lists (i.e., true surrogate of biodiversity require extensive and expensive censuses, and the use of estimator surrogates (e.g., habitats is an appealing alternative. In truth, surrogate effectiveness appears from the literature highly variable both in marine and terrestrial ecosystems, making it difficult to provide practical recommendations for managers. Here, we evaluate how the biodiversity reference data set and its inherent bias can influence effectiveness. Specifically, we defined habitats by geomorphology, rugosity, and benthic cover and architecture criteria, and mapped them with satellite images for a New-Caledonian site. Fish taxonomic and functional lists were elaborated from Underwater Visual Censuses, stratified according to geomorphology and exposure. We then tested if MPA networks designed to maximize habitat richness, diversity and rarity could also effectively maximize fish richness, diversity, and rarity. Effectiveness appeared highly sensitive to the fish census design itself, in relation to the type of habitat map used and the scale of analysis. Spatial distribution of habitats (estimator surrogate's distribution, quantity and location of fish census stations (target surrogate's sampling, and random processes in the MPA design all affected effectiveness to the point that one small change in the data set could lead to opposite conclusions. We suggest that previous conclusions on surrogacy effectiveness, either positive or negative, marine or terrestrial, should be considered with caution, except in instances where very dense data sets were used without pseudo-replication. Although this does not rule out the validity of using surrogates of species lists for conservation planning, the critical joint examination of both target and estimator

  5. Regional hard coral distribution within geomorphic and reef flat ecological zones determined by satellite imagery of the Xisha Islands, South China Sea

    Science.gov (United States)

    Zuo, Xiuling; Su, Fenzhen; Zhao, Huanting; Zhang, Junjue; Wang, Qi; Wu, Di

    2017-05-01

    Coral reefs in the Xisha Islands (also known as the Paracel Islands in English), South China Sea, have experienced dramatic declines in coral cover. However, the current regional scale hard coral distribution of geomorphic and ecological zones, essential for reefs management in the context of global warming and ocean acidification, is not well documented. We analyzed data from field surveys, Landsat-8 and GF-1 images to map the distribution of hard coral within geomorphic zones and reef flat ecological zones. In situ surveys conducted in June 2014 on nine reefs provided a complete picture of reef status with regard to live coral diversity, evenness of coral cover and reef health (live versus dead cover) for the Xisha Islands. Mean coral cover was 12.5% in 2014 and damaged reefs seemed to show signs of recovery. Coral cover in sheltered habitats such as lagoon patch reefs and biotic dense zones of reef flats was higher, but there were large regional differences and low diversity. In contrast, the more exposed reef slopes had high coral diversity, along with high and more equal distributions of coral cover. Mean hard coral cover of other zones was reef system was estimated to cover 1 060 km2, and the emergent reefs covered 787 m2. Hard corals of emergent reefs were considered to cover 97 km2. The biotic dense zone of the reef flat was a very common zone on all simple atolls, especially the broader northern reef flats. The total cover of live and dead coral can reach above 70% in this zone, showing an equilibrium between live and dead coral as opposed to coral and algae. This information regarding the spatial distribution of hard coral can support and inform the management of Xisha reef ecosystems.

  6. 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 reefs.

  7. Coral diseases and bleaching on Colombian Caribbean coral reefs

    Directory of Open Access Journals (Sweden)

    Raúl Navas-Camacho

    2010-05-01

    Full Text Available Since 1998 the National Monitoring System for the Coral Reefs of Colombia (SIMAC has monitored the occurrence of coral bleaching and diseases in some Colombian coral reefs (permanent stations at San Andres Island, Rosario Islands, Tayrona, San Bernardo Islands and Urabá. The main purpose is to evaluate their health status and to understand the factors that have been contributing to their decline. To estimate these occurrences, annual surveys in 126 permanent belt transects (10x2m with different depth intervals (3-6 meters, 9-12 meters and 15-18 meters are performed at all reef sites. Data from the 1998-2004 period, revealed that San Andrés Island had many colonies with diseases (38.9 colonies/m2, and Urabá had high numbers with bleaching (54.4 colonies/m2. Of the seven reported coral diseases studied, Dark Spots Disease (DSD, and White Plague Disease (WPD were noteworthy because they occurred in all Caribbean monitored sites, and because of their high interannual infection incidence. Thirty five species of scleractinian corals were affected by at least one disease and a high incidence of coral diseases on the main reef builders is documented. Bleaching was present in 34 species. During the whole monitoring period, Agaricia agaricites and Siderastrea siderea were the species most severely affected by DSD and bleaching, respectively. Diseases on species such as Agaricia fragilis, A.grahamae, A. humilis, Diploria clivosa, Eusmilia fastigiata, Millepora complanata, and Mycetophyllia aliciae are recorded for first time in Colombia. We present bleaching and disease incidences, kinds of diseases, coral species affected, reef localities studied, depth intervals of surveys, and temporal (years variation for each geographic area. This variation makes difficult to clearly determine defined patterns or general trends for monitored reefs. This is the first long-term study of coral diseases and bleaching in the Southwestern Caribbean, and one of the few

  8. Ningaloo reef: shallow marine habitats mapped using a hyperspectral sensor.

    Directory of Open Access Journals (Sweden)

    Halina T Kobryn

    Full Text Available Research, monitoring and management of large marine protected areas require detailed and up-to-date habitat maps. Ningaloo Marine Park (including the Muiron Islands in north-western Australia (stretching across three degrees of latitude was mapped to 20 m depth using HyMap airborne hyperspectral imagery (125 bands at 3.5 m resolution across the 762 km(2 of reef environment between the shoreline and reef slope. The imagery was corrected for atmospheric, air-water interface and water column influences to retrieve bottom reflectance and bathymetry using the physics-based Modular Inversion and Processing System. Using field-validated, image-derived spectra from a representative range of cover types, the classification combined a semi-automated, pixel-based approach with fuzzy logic and derivative techniques. Five thematic classification levels for benthic cover (with probability maps were generated with varying degrees of detail, ranging from a basic one with three classes (biotic, abiotic and mixed to the most detailed with 46 classes. The latter consisted of all abiotic and biotic seabed components and hard coral growth forms in dominant or mixed states. The overall accuracy of mapping for the most detailed maps was 70% for the highest classification level. Macro-algal communities formed most of the benthic cover, while hard and soft corals represented only about 7% of the mapped area (58.6 km(2. Dense tabulate coral was the largest coral mosaic type (37% of all corals and the rest of the corals were a mix of tabulate, digitate, massive and soft corals. Our results show that for this shallow, fringing reef environment situated in the arid tropics, hyperspectral remote sensing techniques can offer an efficient and cost-effective approach to mapping and monitoring reef habitats over large, remote and inaccessible areas.

  9. Small cryptopredators contribute to high predation rates on coral reefs

    Science.gov (United States)

    Goatley, Christopher H. R.; González-Cabello, Alonso; Bellwood, David R.

    2017-03-01

    Small fishes suffer high mortality rates on coral reefs, primarily due to predation. Although studies have identified the predators of early post-settlement fishes, the predators of small cryptobenthic fishes remain largely unknown. We therefore used a series of mesocosm experiments with natural habitat and cryptobenthic fish communities to identify the impacts of a range of small potential predators, including several invertebrates, on prey fish populations. While there was high variability in predation rates, many members of the cryptobenthic fish community act as facultative cryptopredators, being prey when small and piscivores when larger. Surprisingly, we also found that smashing mantis shrimps may be important fish predators. Our results highlight the diversity of the predatory community on coral reefs and identify previously unknown trophic links in these complex ecosystems.

  10. 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...

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Climate change impacts on coral reefs: synergies with local effects, possibilities for acclimation, and management implications.

    Science.gov (United States)

    Ateweberhan, Mebrahtu; Feary, David A; Keshavmurthy, Shashank; Chen, Allen; Schleyer, Michael H; Sheppard, Charles R C

    2013-09-30

    Most reviews concerning the impact of climate change on coral reefs discuss independent effects of warming or ocean acidification. However, the interactions between these, and between these and direct local stressors are less well addressed. This review underlines that coral bleaching, acidification, and diseases are expected to interact synergistically, and will negatively influence survival, growth, reproduction, larval development, settlement, and post-settlement development of corals. Interactions with local stress factors such as pollution, sedimentation, and overfishing are further expected to compound effects of climate change. Reduced coral cover and species composition following coral bleaching events affect coral reef fish community structure, with variable outcomes depending on their habitat dependence and trophic specialisation. Ocean acidification itself impacts fish mainly indirectly through disruption of predation- and habitat-associated behavior changes. Zooxanthellate octocorals on reefs are often overlooked but are substantial occupiers of space; these also are highly susceptible to bleaching but because they tend to be more heterotrophic, climate change impacts mainly manifest in terms of changes in species composition and population structure. Non-calcifying macroalgae are expected to respond positively to ocean acidification and promote microbe-induced coral mortality via the release of dissolved compounds, thus intensifying phase-shifts from coral to macroalgal domination. Adaptation of corals to these consequences of CO2 rise through increased tolerance of corals and successful mutualistic associations between corals and zooxanthellae is likely to be insufficient to match the rate and frequency of the projected changes. Impacts are interactive and magnified, and because there is a limited capacity for corals to adapt to climate change, global targets of carbon emission reductions are insufficient for coral reefs, so lower targets should be

  16. Fishing down nutrients on coral reefs

    Science.gov (United States)

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

    2016-08-01

    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.

  17. Water Quality Standards for Coral Reef Protection

    Science.gov (United States)

    The U.S. Clean Water Act provides a legal framework to protect coastal biological resources such as coral reefs, mangrove forests, and seagrass meadows from the damaging effects of human activities. Even though many resources are protected under this authority, water quality stan...

  18. Mapping Coral Reef Resilience Indicators Using Field and Remotely Sensed Data

    Directory of Open Access Journals (Sweden)

    Stuart Phinn

    2013-03-01

    Full Text Available 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 richness, density of juvenile corals and the cover of live coral and crustose coralline algae. We use high spatial resolution satellite data to derive environmental predictors and use these in random forest models, with field observations, to predict resilience indicator values at unsampled locations. Predictions are compared with those obtained from universal kriging and from a baseline model. Prediction errors are estimated using cross-validation, and the ability to map each resilience indicator is quantified as the percentage reduction in prediction error compared to the baseline model. Results are most promising (percentage reduction = 18.3% for mapping the cover of live coral and crustose coralline algae and least promising (percentage reduction = 0% for coral diversity. Our study has demonstrated one approach to map indicators of coral reef resilience. In the context of MPA network planning, the potential to consider reef resilience in addition to habitat and feature representation in decision-support software now exists, allowing planners to integrate aspects of reef resilience in MPA network development.

  19. The impact of benthic algae on the settlement of a reef-building coral

    Science.gov (United States)

    Diaz-Pulido, G.; Harii, S.; McCook, L. J.; Hoegh-Guldberg, O.

    2010-03-01

    The capacity of corals to re-establish in degraded and algal-dominated habitats will depend on the effects of algae on coral settlement and growth. We tested the effect of 11 macroalgal species, of widely different functional-forms, on swimming and settlement by larvae of the coral Platygyra daedalea from the Great Barrier Reef. Algal turfs and the crustose calcareous algae groups had minor effects on coral settlement, while upright calcareous and fleshy macroalgae inhibited settlement. However, the extent of inhibition of larval settlement differed amongst upright macroalgal species, variations that were not well explained by physical differences and probably reflect chemical differences not explained by functional-form. Thus, while algal functional-form is useful in identifying general competition patterns, more detailed taxonomic and chemical approaches may be required to fully understand algal effects on corals. Different macroalgal communities on degraded reefs may have different effects on coral settlement, and hence on coral population resilience.

  20. 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.

  1. Optimising Land-Sea Management for Inshore Coral Reefs

    Science.gov (United States)

    Gilby, Ben L.; Olds, Andrew D.; Connolly, Rod M.; Stevens, Tim; Henderson, Christopher J.; Maxwell, Paul S.; Tibbetts, Ian R.; Schoeman, David S.; Rissik, David; Schlacher, Thomas A.

    2016-01-01

    Management authorities seldom have the capacity to comprehensively address the full suite of anthropogenic stressors, particularly in the coastal zone where numerous threats can act simultaneously to impact reefs and other ecosystems. This situation requires tools to prioritise management interventions that result in optimum ecological outcomes under a set of constraints. Here we develop one such tool, introducing a Bayesian Belief Network to model the ecological condition of inshore coral reefs in Moreton Bay (Australia) under a range of management actions. Empirical field data was used to model a suite of possible ecological responses of coral reef assemblages to five key management actions both in the sea (e.g. expansion of reserves, mangrove & seagrass restoration, fishing restrictions) and on land (e.g. lower inputs of sediment and sewage from treatment plants). Models show that expanding marine reserves (a ‘marine action’) and reducing sediment inputs from the catchments (a ‘land action’) were the most effective investments to achieve a better status of reefs in the Bay, with both having been included in >58% of scenarios with positive outcomes, and >98% of the most effective (5th percentile) scenarios. Heightened fishing restrictions, restoring habitats, and reducing nutrient discharges from wastewater treatment plants have additional, albeit smaller effects. There was no evidence that combining individual management actions would consistently produce sizeable synergistic until after maximum investment on both marine reserves (i.e. increasing reserve extent from 31 to 62% of reefs) and sediments (i.e. rehabilitating 6350 km of waterways within catchments to reduce sediment loads by 50%) were implemented. The method presented here provides a useful tool to prioritize environmental actions in situations where multiple competing management interventions exist for coral reefs and in other systems subjected to multiple stressor from the land and the sea

  2. Coral identity underpins architectural complexity on Caribbean reefs.

    Science.gov (United States)

    Alvarez-Filip, Lorenzo; Dulvy, Nicholas K; Côte, Isabelle M; Watkinson, Andrew R; Gill, Jennifer A

    2011-09-01

    The architectural complexity of ecosystems can greatly influence their capacity to support biodiversity and deliver ecosystem services. Understanding the components underlying this complexity can aid the development of effective strategies for ecosystem conservation. Caribbean coral reefs support and protect millions of livelihoods, but recent anthropogenic change is shifting communities toward reefs dominated by stress-resistant coral species, which are often less architecturally complex. With the regionwide decline in reef fish abundance, it is becoming increasingly important to understand changes in coral reef community structure and function. We quantify the influence of coral composition, diversity, and morpho-functional traits on the architectural complexity of reefs across 91 sites at Cozumel, Mexico. Although reef architectural complexity increases with coral cover and species richness, it is highest on sites that are low in taxonomic evenness and dominated by morpho-functionally important, reef-building coral genera, particularly Montastraea. Sites with similar coral community composition also tend to occur on reefs with very similar architectural complexity, suggesting that reef structure tends to be determined by the same key species across sites. Our findings provide support for prioritizing and protecting particular reef types, especially those dominated by key reef-building corals, in order to enhance reef complexity.

  3. Reef fishes in biodiversity hotspots are at greatest risk from loss of coral species.

    Science.gov (United States)

    Holbrook, Sally J; Schmitt, Russell J; Messmer, Vanessa; Brooks, Andrew J; Srinivasan, Maya; 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 particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia). Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity) in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems.

  4. Reef fishes in biodiversity hotspots are at greatest risk from loss of coral species.

    Directory of Open Access Journals (Sweden)

    Sally J Holbrook

    Full Text Available 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 particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia. Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems.

  5. Feasibility of a Regionwide Probability Survey for Coral Reef Fish in Puerto Rico and the U.S. Virgin Islands

    National Research Council Canada - National Science Library

    Bryan, David R; Smith, Steven G; Ault, Jerald S; Feeley, Michael W; Menza, Charles W

    2016-01-01

    .... Caribbean were used in conjunction with detailed bathymetric and habitat maps to develop a probability sampling design and investigate the feasibility of conducting a regionwide coral reef fish survey...

  6. Functional Valuation of Ecosystem Services on Bonaire: an ecological analysis of ecosystem functions provided by coral reefs

    NARCIS (Netherlands)

    Beek, van I.J.M.

    2011-01-01

    This research is a semi-quantitative analysis of the functional value of coral reef habitats on Bonaire to support ecosystem services. It is part of an economic valuation study of marine and terrestrial ecosystem services on Bonaire.

  7. Functional Valuation of Ecosystem Services on Bonaire: an ecological analysis of ecosystem functions provided by coral reefs

    NARCIS (Netherlands)

    Beek, van I.J.M.

    2011-01-01

    This research is a semi-quantitative analysis of the functional value of coral reef habitats on Bonaire to support ecosystem services. It is part of an economic valuation study of marine and terrestrial ecosystem services on Bonaire.

  8. The structure and composition of Holocene coral reefs in the Middle Florida Keys

    Science.gov (United States)

    Toth, Lauren T.; Stathakopoulos, Anastasios; Kuffner, Ilsa B.

    2016-07-21

    The Florida Keys reef tract (FKRT) is the largest coral-reef ecosystem in the continental United States. The modern FKRT extends for 362 kilometers along the coast of South Florida from Dry Tortugas National Park in the southwest, through the Florida Keys National Marine Sanctuary (FKNMS), to Fowey Rocks reef in Biscayne National Park in the northeast. Most reefs along the FKRT are sheltered by the exposed islands of the Florida Keys; however, large channels are located between the islands of the Middle Keys. These openings allow for tidal transport of water from Florida Bay onto reefs in the area. The characteristics of the water masses coming from Florida Bay, which can experience broad swings in temperature, salinity, nutrients, and turbidity over short periods of time, are generally unfavorable or “inimical” to coral growth and reef development.Although reef habitats are ubiquitous throughout most of the Upper and Lower Keys, relatively few modern reefs exist in the Middle Keys most likely because of the impacts of inimical waters from Florida Bay. The reefs that are present in the Middle Keys generally are poorly developed compared with reefs elsewhere in the region. For example, Acropora palmata has been the dominant coral on shallow-water reefs in the Caribbean over the last 1.5 million years until populations of the coral declined throughout the region in recent decades. Although A. palmata was historically abundant in the Florida Keys, it was conspicuously absent from reefs in the Middle Keys. Instead, contemporary reefs in the Middle Keys have been dominated by occasional massive (that is, boulder or head) corals and, more often, small, non-reef-building corals.Holocene reef cores have been collected from many locations along the FKRT; however, despite the potential importance of the history of reefs in the Middle Florida Keys to our understanding of the environmental controls on reef development throughout the FKRT, there are currently no published

  9. Spatiotemporal variations of live coral cover in the northern Mesoamerican Reef System, Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Linda M. Barranco

    2016-06-01

    Full Text Available Evaluating the response of coral assemblages to different disturbances is important because variations in species composition may have consequences for ecosystem functioning due to their different functional roles in coral reefs. This study evaluates changes in diversity, structure and composition of coral assemblages of the coral reefs of two national parks in the northern sector of the Mesoamerican Barrier Reef System spanning the period from 2006 to 2012, just after the impact of two hurricanes in the area. Coral assemblages in the Cancún National Park included fewer species and lower live coral coverage ( < 15% than those recorded in Cozumel. In the Cancún National Park, the species with the highest coral cover was Porites astreoides (more than 40% relative cover, and no significant temporal changes were observed in live coral cover and species composition. On the other hand, in the Cozumel National Park the dominant species were Agaricia agaricites, Siderastrea siderea and Porites astreoides, and the coral reefs showed an increase in live coral cover from 16% in 2006 to 29% in 2012. The dynamics of coral assemblages differed between the two parks: while there is an apparent stability in the current composition of the Cancún reefs, the Cozumel reefs show an increase in the abundance of the aforementioned dominant species. However, it is possible that the population characteristics of the species that dominate the coral assemblages in both national parks, such as those of fast population growth and of small colony size, do not entirely fulfill the main function of accretion and habitat heterogeneity, and more research is therefore needed to test this hypothesis.

  10. UNMIXING-BASED DENOISING AS A PRE-PROCESSING STEP FOR CORAL REEF ANALYSIS

    Directory of Open Access Journals (Sweden)

    D. Cerra

    2017-05-01

    Full Text Available Coral reefs, among the world’s most biodiverse and productive submerged habitats, have faced several mass bleaching events due to climate change during the past 35 years. In the course of this century, global warming and ocean acidification are expected to cause corals to become increasingly rare on reef systems. This will result in a sharp decrease in the biodiversity of reef communities and carbonate reef structures. Coral reefs may be mapped, characterized and monitored through remote sensing. Hyperspectral images in particular excel in being used in coral monitoring, being characterized by very rich spectral information, which results in a strong discrimination power to characterize a target of interest, and separate healthy corals from bleached ones. Being submerged habitats, coral reef systems are difficult to analyse in airborne or satellite images, as relevant information is conveyed in bands in the blue range which exhibit lower signal-to-noise ratio (SNR with respect to other spectral ranges; furthermore, water is absorbing most of the incident solar radiation, further decreasing the SNR. Derivative features, which are important in coral analysis, result greatly affected by the resulting noise present in relevant spectral bands, justifying the need of new denoising techniques able to keep local spatial and spectral features. In this paper, Unmixing-based Denoising (UBD is used to enable analysis of a hyperspectral image acquired over a coral reef system in the Red Sea based on derivative features. UBD reconstructs pixelwise a dataset with reduced noise effects, by forcing each spectrum to a linear combination of other reference spectra, exploiting the high dimensionality of hyperspectral datasets. Results show clear enhancements with respect to traditional denoising methods based on spatial and spectral smoothing, facilitating the coral detection task.

  11. Unmixing-Based Denoising as a Pre-Processing Step for Coral Reef Analysis

    Science.gov (United States)

    Cerra, D.; Traganos, D.; Gege, P.; Reinartz, P.

    2017-05-01

    Coral reefs, among the world's most biodiverse and productive submerged habitats, have faced several mass bleaching events due to climate change during the past 35 years. In the course of this century, global warming and ocean acidification are expected to cause corals to become increasingly rare on reef systems. This will result in a sharp decrease in the biodiversity of reef communities and carbonate reef structures. Coral reefs may be mapped, characterized and monitored through remote sensing. Hyperspectral images in particular excel in being used in coral monitoring, being characterized by very rich spectral information, which results in a strong discrimination power to characterize a target of interest, and separate healthy corals from bleached ones. Being submerged habitats, coral reef systems are difficult to analyse in airborne or satellite images, as relevant information is conveyed in bands in the blue range which exhibit lower signal-to-noise ratio (SNR) with respect to other spectral ranges; furthermore, water is absorbing most of the incident solar radiation, further decreasing the SNR. Derivative features, which are important in coral analysis, result greatly affected by the resulting noise present in relevant spectral bands, justifying the need of new denoising techniques able to keep local spatial and spectral features. In this paper, Unmixing-based Denoising (UBD) is used to enable analysis of a hyperspectral image acquired over a coral reef system in the Red Sea based on derivative features. UBD reconstructs pixelwise a dataset with reduced noise effects, by forcing each spectrum to a linear combination of other reference spectra, exploiting the high dimensionality of hyperspectral datasets. Results show clear enhancements with respect to traditional denoising methods based on spatial and spectral smoothing, facilitating the coral detection task.

  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. Elkhorn and Staghorn Corals Critical Habitat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent the critical habitat for elkhorn coral (Acropora palmata) and staghorn coral (A. cervicornis) as designated by 73 FR 72210, November 26, 2008,...

  14. Predation risk, resource quality, and reef structural complexity shape territoriality in a coral reef herbivore.

    Directory of Open Access Journals (Sweden)

    Laura B Catano

    Full Text Available For many species securing territories is important for feeding and reproduction. Factors such as competition, habitat availability, and male characteristics can influence an individual's ability to establish and maintain a territory. The risk of predation can have an important influence on feeding and reproduction; however, few have studied its effect on territoriality. We investigated territoriality in a haremic, polygynous species of coral reef herbivore, Sparisoma aurofrenatum (redband parrotfish, across eight reefs in the Florida Keys National Marine Sanctuary that were either protected or unprotected from fishing of piscivorous fishes. We examined how territory size and quality varied with reef protection status, competition, predation risk, and male size. We then determined how territory size and quality influenced harem size and female size to understand the effect of territoriality on reproductive potential. We found that protected reefs trended towards having more large predatory fishes and that territories there were smaller but had greater algal nutritional quality relative to unprotected reefs. Our data suggest that even though males in protected sites have smaller territories, which support fewer females, they may improve their reproductive potential by choosing nutritionally rich areas, which support larger females. Thus, reef protection appears to shape the trade-off that herbivorous fishes make between territory size and quality. Furthermore, we provide evidence that males in unprotected sites, which are generally less complex than protected sites, choose territories with higher structural complexity, suggesting the importance of this type of habitat for feeding and reproduction in S. aurofrenatum. Our work argues that the loss of corals and the resulting decline in structural complexity, as well as management efforts to protect reefs, could alter the territory dynamics and reproductive potential of important herbivorous fish

  15. Predation risk, resource quality, and reef structural complexity shape territoriality in a coral reef herbivore.

    Science.gov (United States)

    Catano, Laura B; Gunn, Bridgette K; Kelley, Megan C; Burkepile, Deron E

    2015-01-01

    For many species securing territories is important for feeding and reproduction. Factors such as competition, habitat availability, and male characteristics can influence an individual's ability to establish and maintain a territory. The risk of predation can have an important influence on feeding and reproduction; however, few have studied its effect on territoriality. We investigated territoriality in a haremic, polygynous species of coral reef herbivore, Sparisoma aurofrenatum (redband parrotfish), across eight reefs in the Florida Keys National Marine Sanctuary that were either protected or unprotected from fishing of piscivorous fishes. We examined how territory size and quality varied with reef protection status, competition, predation risk, and male size. We then determined how territory size and quality influenced harem size and female size to understand the effect of territoriality on reproductive potential. We found that protected reefs trended towards having more large predatory fishes and that territories there were smaller but had greater algal nutritional quality relative to unprotected reefs. Our data suggest that even though males in protected sites have smaller territories, which support fewer females, they may improve their reproductive potential by choosing nutritionally rich areas, which support larger females. Thus, reef protection appears to shape the trade-off that herbivorous fishes make between territory size and quality. Furthermore, we provide evidence that males in unprotected sites, which are generally less complex than protected sites, choose territories with higher structural complexity, suggesting the importance of this type of habitat for feeding and reproduction in S. aurofrenatum. Our work argues that the loss of corals and the resulting decline in structural complexity, as well as management efforts to protect reefs, could alter the territory dynamics and reproductive potential of important herbivorous fish species.

  16. Coral biodiversity and bioconstruction in the northern sector of the Mesoamerican Reef system

    Directory of Open Access Journals (Sweden)

    Fabian Alejandro Rodriguez-Zaragoza

    2015-03-01

    Full Text Available As the impact of anthropogenic activity and climate change continue to accelerate rates of degradation on Caribbean coral reefs, conservation and restoration faces greater challenges. At at this stage, of particular importance in coral reefs, is to recognize and to understand the structural spatial patterns of benthic assemblages. We developed a field-based framework of a Caribbean reefscape benthic structure by using hermatypic corals as an indicator group of global biodiversity and bio-construction patterns in eleven reefs of the northern sector of the Mesoamerican Barrier Reef System (nsMBRS. Four hundred and seventy four video-transects (50 m long by 0.4 m wide were performed throughout a gradient of reef complexity from north to south (∼400 km to identify coral species, families and ensembles of corals. Composition and abundance of species, families and ensembles showed differences among reefs. In the northern zone, the reefs had shallow, partial reef developments with low diversities, dominated by Acropora palmata, Siderastrea spp., Pseudodiploria strigosa and Agaricia tenuifolia. In the central and southern zones, reefs presented extensive developments, high habitat heterogeneity, and the greatest diversity and dominance of Orbicella annularis and Orbicella faveolata. These two species determined the structure and diversity of corals in the central and southern zones of the nsMBRS and their bio-construction in these zones is unique in the Caribbean. Their abundance and distribution depended on the reef habitat area, topographic complexity and species richness. Orbicella species complex were crucial for maintaining the biodiversity and bio-construction of the central and southern zones while A. palmata in the northern zones of the nsMBRS.

  17. Ingestion of Microplastics and Their Impact on Calcification in Reef-Building Corals

    Science.gov (United States)

    Zink, C. P.; Smith, R. T.

    2016-02-01

    Since the early 1970's, researchers began identifying plastics and other sources of litter as harmful to ecosystems. In recent years, there's been a growing concern about microscopic plastic debris (microplastics) and its impact on marine organisms. Likewise, microplastics are currently and continuously being documented from environmental samples on a global scale. The ecosystems most likely affected by their presence are shallow marine habitats, such as near-shore coral reefs. One concern is that microplastics may be ingested by reef-building corals and negatively impact their physiology. In this study, two species of Caribbean reef-building corals, Orbicella faveolata and Porites porites were investigated for rates of ingesting microplastics. Coral samples were incubated with 100μm micro-beads manufactured with a fluorescent label to aid in recovery and quantification from the coral tissue. Following the consumption of plastic, we measured instantaneous rates of calcification as a proxy for physiological performance compared to controls. Our results indicate that corals ingest microplastic particles and maintain them internally for at least 24 hours. Our initial findings suggest that the ingestion of ≥ 3 microplastic particles cm-2 may negatively impact rates of coral calcification. In light of these preliminary findings, further investigations should examine the long-term effect of environmentally relevant concentrations of microplastics on reef corals and its potential detriment to reef building capacity.

  18. 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.

  19. 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...

  20. 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...

  1. Evaluation of Stony Coral Indicators for Coral Reef ...

    Science.gov (United States)

    Colonies of reef-building stony corals at 57 stations around St. Croix, U.S. Virgin Islands were characterized by species, size and percentage of living tissue. Taxonomic, biological and physical indicators of coral condition were derived from these measurements and assessed for their response to gradients of human disturbance. The purpose of the study was to identify indicators that could be used for regulatory assessments under authority of the Clean Water Act--this requires that indicators distinguish anthropogenic disturbances from natural variation. Stony coral indicators were tested for correlation with human disturbance across gradients located on three different sides of the island. At the most intensely disturbed location, five of eight primary indicators were highly correlated with distance from the source of disturbance: Coral taxa richness, average colony size, the coefficient of variation of colony size (an indicator of colony size heterogeneity), total topographic coral surface area, and live coral surface area. An additional set of exploratory indicators related to rarity, reproductive and spawning mode, and taxonomic identity were also screened for association with disturbance at the same location. For the other two locations, there were no significant changes in indicator values and therefore no discernible effects of human activity. Coral indicators demonstrated sufficient precision to detect levels of change that would be applicable in a regio

  2. Tight coupling between coral reef morphology and mapped resilience in the Red Sea.

    Science.gov (United States)

    Rowlands, Gwilym; Purkis, Sam; Bruckner, Andrew

    2016-04-30

    Lack of knowledge on the conservation value of different reef types can stymie decision making, and result in less optimal management solutions. Addressing the information gap of coral reef resilience, we produce a map-based Remote Sensed Resilience Index (RSRI) from data describing the spatial distribution of stressors, and properties of reef habitats on the Farasan Banks, Saudi Arabia. We contrast the distribution of this index among fourteen reef types, categorized on a scale of maturity that includes juvenile (poorly aggraded), mature (partially aggraded), and senile (fully aggraded) reefs. Sites with high reef resilience can be found in most detached reef types; however they are most common in mature reefs. We aim to stimulate debate on the coupling that exists between geomorphology and conservation biology, and consider how such information can be used to inform management decisions.

  3. 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.

  4. Fish movement patterns in Virgin Islands National Park, Virgin Islands Coral Reef National Monument and adjacent waters

    OpenAIRE

    Friedlander, Alan M.; Monaco, Mark E.; Clark, Randy; Pittman, Simon J.; Beets, Jim; Boulon, Rafe; Callender, Russell; Christensen, John; Hile, Sarah D.; Kendall , Matt S.; Miller, Jeff; Rogers , Caroline; Starnoulis, Kosta; Wedding, Lisa; Roberson, Kimberly

    2013-01-01

    NOAA’s National Centers for Coastal Ocean Science (NCCOS)-Center for Coastal Monitoring and Assessment’s (CCMA) Biogeography Branch, National Park Service (NPS), US Geological Survey, and the University of Hawaii used acoustic telemetry to quantify spatial patterns and habitat affinities of reef fishes around the island of St. John, US Virgin Islands. The objective of the study was to define the movements of reef fishes among habitats within and between the Virgin Islands Coral Reef National ...

  5. Oman's coral reefs: A unique ecosystem challenged by natural and man-related stresses and in need of conservation.

    Science.gov (United States)

    Burt, J A; Coles, S; van Lavieren, H; Taylor, O; Looker, E; Samimi-Namin, K

    2016-04-30

    Oman contains diverse and abundant reef coral communities that extend along a coast that borders three environmentally distinct water bodies, with corals existing under unique and often stressful environmental conditions. In recent years Oman's reefs have undergone considerable change due to recurrent predatory starfish outbreaks, cyclone damage, harmful algal blooms, and other stressors. In this review we summarize current knowledge of the biology and status of corals in Oman, particularly in light of recent stressors and projected future threats, and examine current reef management practices. Oman's coral communities occur in marginal environmental conditions for reefs, and hence are quite vulnerable to anthropogenic effects. We recommend a focus on developing conservation-oriented coral research to guide proactive management and expansion of the number and size of designated protected areas in Oman, particularly those associated with critical coral habitat.

  6. The COral-REef Front (COREF Project

    Directory of Open Access Journals (Sweden)

    John A. and Katherine G. Jackson

    2007-09-01

    Full Text Available The First International Workshop on the COral-REef Front (COREF project was held on 14−19 January 2007 in Okinawa-jima, southwestern Japan to discuss objectives, required laboratory analyses and techniques, potential drilling sites, and scientific proposals for the Integrated Ocean Drilling Program (IODP and the International Continental Scientific Drilling Program (ICDP. This article briefly introduces the project and reports the outcome of the First International Workshop on the COREF Project.

  7. Threatened Reef Corals of the World

    OpenAIRE

    Danwei Huang

    2012-01-01

    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 al...

  8. Human impacts on Caribbean coral reef ecosystems

    OpenAIRE

    Hardt, Marah Justine

    2007-01-01

    Fishing is one of the oldest anthropogenic disturbances in the ocean, differing from other impacts in its direct removal of biomass from the ecosystem. Despite the centuries of fishing activities, there is much we still do not understand regarding the effects of fish removal on the benthic community. I use an interdisciplinary approach to investigate the affect of human disturbance, primarily the alteration of fish communities, on major functional groups of coral reefs, over extended temporal...

  9. Ecological States and the Resilience of Coral Reefs

    Directory of Open Access Journals (Sweden)

    Tim McClanahan

    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

  10. Coral Reef Remote Sensing: Helping Managers Protect Reefs in a Changing Climate

    Science.gov (United States)

    Eakin, C.; Liu, G.; Li, J.; Muller-Karger, F. E.; Heron, S. F.; Gledhill, D. K.; Christensen, T.; Rauenzahn, J.; Morgan, J.; Parker, B. A.; Skirving, W. J.; Nim, C.; Burgess, T.; Strong, A. E.

    2010-12-01

    Climate change and ocean acidification are already having severe impacts on coral reef ecosystems. Warming oceans have caused corals to bleach, or expel their symbiotic algae (zooxanthellae) with alarming frequency and severity and have contributed to a rise in coral infectious diseases. Ocean acidification is reducing the availability of carbonate ions needed by corals and many other marine organisms to build structural components like skeletons and shells and may already be slowing the coral growth. These two impacts are already killing corals and slowing reef growth, reducing biodiversity and the structure needed to provide crucial ecosystem services. NOAA’s Coral Reef Watch (CRW) uses a combination of satellite data, in situ observations, and models to provide coral reef managers, scientists, and others with information needed to monitor threats to coral reefs. The advance notice provided by remote sensing and models allows resource managers to protect corals, coral reefs, and the services they provide, although managers often encounter barriers to implementation of adaptation strategies. This talk will focus on application of NOAA’s satellite and model-based tools that monitor the risk of mass coral bleaching on a global scale, ocean acidification in the Caribbean, and coral disease outbreaks in selected regions, as well as CRW work to train managers in their use, and barriers to taking action to adapt to climate change. As both anthropogenic CO2 and temperatures will continue to rise, local actions to protect reefs are becoming even more important.

  11. When giants turn up: sighting trends, environmental influences and habitat use of the manta ray Manta alfredi at a coral reef.

    Directory of Open Access Journals (Sweden)

    Fabrice R A Jaine

    Full Text Available Manta rays Manta alfredi are present all year round at Lady Elliot Island (LEI in the southern Great Barrier Reef, Australia, with peaks in abundance during autumn and winter. Drivers influencing these fluctuations in abundance of M. alfredi at the site remain uncertain. Based on daily count, behavioural, weather and oceanographic data collected over a three-year period, this study examined the link between the relative number of sightings of manta rays at LEI, the biophysical environment, and the habitat use of individuals around the LEI reef using generalised additive models. The response variable in each of the three generalised additive models was number of sightings (per trip at sea of cruising, cleaning or foraging M. alfredi. We used a set of eleven temporal, meteorological, biological, oceanographic and lunar predictor variables. Results for cruising, cleaning and foraging M. alfredi explained 27.5%, 32.8% and 36.3% of the deviance observed in the respective models and highlighted five predictors (year, day of year, wind speed, chlorophyll-a concentration and fraction of moon illuminated as common influences to the three models. There were more manta rays at LEI in autumn and winter, slower wind speeds, higher productivity, and around the new and full moon. The winter peak in sightings of foraging M. alfredi was found to precede peaks in cleaning and cruising activity around the LEI reef, which suggests that enhanced food availability may be a principal driver for this seasonal aggregation. A spatial analysis of behavioural observations highlighted several sites around the LEI reef as 'multi-purpose' areas where cleaning and foraging activities commonly occur, while the southern end of the reef is primarily a foraging area. The use of extensive citizen science datasets, such as those collected by dive operators in this study, is encouraged as they can provide valuable insights into a species' ecology.

  12. Revealing the regime of shallow coral reefs at patch scale by continuous spatial modeling

    Directory of Open Access Journals (Sweden)

    Antoine eCollin

    2014-11-01

    Full Text Available Reliably translating real-world spatial patterns of ecosystems is critical for understanding processes susceptible to reinforce resilience. However the great majority of studies in spatial ecology use thematic maps to describe habitats and species in a binary scheme. By discretizing the transitional areas and neglecting the gradual replacement across a given space, the thematic approach may suffer from substantial limitations when interpreting patterns created by many continuous variables. Here, local and regional spectral proxies were used to design and spatially map at very fine scale a continuous index dedicated to one of the most complex seascapes, the coral reefscape. Through a groundbreaking merge of bottom-up and top-down approach, we demonstrate that three to seven-habitat continuous indices can be modeled by nine, six, four and three spectral proxies, respectively, at 0.5 m spatial resolution using hand- and spaceborne measurements. We map the seven-habitat continuous index, spanning major Indo-Pacific coral reef habitats through the far red-green normalized difference ratio over the entire lagoon of a low (Tetiaroa atoll and a high volcanic (Moorea island in French Polynesia with 84% and 82% accuracy, respectively. Further examinations of the two resulting spatial models using a customized histoscape (density function of model values distributed on a concentric strip across the reef crest-coastline distance show that Tetiaroa exhibits a greater variety of coral reef habitats than Moorea. By designing such easy-to-implement, transferrable spectral proxies of coral reef regime, this study initiates a framework for spatial ecologists tackling coral reef biodiversity, responses to stresses, perturbations and shifts. We discuss the limitations and contributions of our findings towards the study of worldwide coral reef resilience following stochastic environmental change.

  13. Recent Advances in Understanding the Effects of Climate Change on Coral Reefs

    Directory of Open Access Journals (Sweden)

    Andrew S. Hoey

    2016-05-01

    Full Text Available 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 likely to have the greatest influence on the structure of coral and fish assemblages, at least over short–medium timeframes. Recent evidence of increases in coral bleaching thresholds, local genetic adaptation and inheritance of heat tolerance suggest that coral populations may have some capacity to respond to warming, although the extent to which these changes can keep pace with changing environmental conditions is unknown. For coral reef fishes, current evidence indicates increasing seawater temperature will be a major determinant of future assemblages, through both habitat degradation and direct effects on physiology and behaviour. The effects of climate change are, however, being compounded by a range of anthropogenic disturbances, which may undermine the capacity of coral reef organisms to acclimate and/or adapt to specific changes in environmental conditions.

  14. 10th Anniversary Review: a changing climate for coral reefs.

    Science.gov (United States)

    Lough, Janice M

    2008-01-01

    Tropical coral reefs are charismatic ecosystems that house a significant proportion of the world's marine biodiversity. Their valuable goods and services are fundamental to the livelihood of large coastal populations in the tropics. The health of many of the world's coral reefs, and the goods and services they provide, have already been severely compromised, largely due to over-exploitation by a range of human activities. These local-scale impacts, with the appropriate government instruments, support and management actions, can potentially be controlled and even ameliorated. Unfortunately, other human actions (largely in countries outside of the tropics), by changing global climate, have added additional global-scale threats to the continued survival of present-day coral reefs. Moderate warming of the tropical oceans has already resulted in an increase in mass coral bleaching events, affecting nearly all of the world's coral reef regions. The frequency of these events will only increase as global temperatures continue to rise. Weakening of coral reef structures will be a more insidious effect of changing ocean chemistry, as the oceans absorb part of the excess atmospheric carbon dioxide. More intense tropical cyclones, changed atmospheric and ocean circulation patterns will all affect coral reef ecosystems and the many associated plants and animals. Coral reefs will not disappear but their appearance, structure and community make-up will radically change. Drastic greenhouse gas mitigation strategies are necessary to prevent the full consequences of human activities causing such alterations to coral reef ecosystems.

  15. CORAL REEFS. Genomic determinants of coral heat tolerance across latitudes.

    Science.gov (United States)

    Dixon, Groves B; Davies, Sarah W; Aglyamova, Galina A; Meyer, Eli; Bay, Line K; Matz, Mikhail V

    2015-06-26

    As global warming continues, reef-building corals could avoid local population declines through "genetic rescue" involving exchange of heat-tolerant genotypes across latitudes, but only if latitudinal variation in thermal tolerance is heritable. Here, we show an up-to-10-fold increase in odds of survival of coral larvae under heat stress when their parents come from a warmer lower-latitude location. Elevated thermal tolerance was associated with heritable differences in expression of oxidative, extracellular, transport, and mitochondrial functions that indicated a lack of prior stress. Moreover, two genomic regions strongly responded to selection for thermal tolerance in interlatitudinal crosses. These results demonstrate that variation in coral thermal tolerance across latitudes has a strong genetic basis and could serve as raw material for natural selection. Copyright © 2015, American Association for the Advancement of Science.

  16. 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

  17. 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

  18. 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

  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.

  20. Balance of constructive and destructive carbonate processes on mesophotic coral reefs

    Science.gov (United States)

    Weinstein, D. K.; Klaus, J. S.; Smith, T. B.; Helmle, K. P.; Marshall, D.

    2013-12-01

    Net carbonate accumulation of coral reefs is the product of both constructive and destructive processes that can ultimately influence overall reef geomorphology. Differences in these processes with depth may in part explain why the coral growth-light intensity association does no result in the traditionally theorized reef accretion decrease with depth. Until recently, physical sampling limitations had prevented the acquisition of sedimentary data needed to assess in situ carbonate accumulation in mesophotic reefs (30-150 m). Coral framework production, secondary carbonate production (calcareous encrusters), and bioerosion, the three most critical components of net carbonate accumulation, were analyzed in mesophotic reefs more than 10 km south of St. Thomas, U.S. Virgin Islands along a very gradual slope that limits sediment transport and sedimentation. Recently dead samples of the massive coral, Orbicella annularis collected from three structurally different upper mesophotic coral reef habitats (30-45 m) were cut parallel to the primary growth axis to identify density banding through standard x-radiographic techniques. Assuming annual banding, mesophotic linear extension rates were calculated on the order of 0.7-1.5 mm/yr. Weight change of experimental coral substrates exposed for 3 years indicate differing rates (1.1-17.2 g/yr) of bioerosion and secondary accretion between mesophotic sites. When correcting bioerosion rates for high mesophotic skeletal density, carbonate accumulation rates were found to vary significantly between neighboring mesophotic reefs with distinctive structures. Results imply variable rates of mesophotic reef net carbonate accretion with the potential to influence overall reef/platform morphology, including localized mesophotic reef structure.

  1. Mapping the Rainforest of the Sea: Global Coral Reef Maps for Global Conservation

    Science.gov (United States)

    Robinson, Julie A.

    2006-01-01

    Coral reefs are the center of marine biodiversity, yet are under threat with an estimated 60% of coral reef habitats considered at risk by the World Resources Institute. The location and extent of coral reefs in the world are the basic information required for resource management and as a baseline for monitoring change. A NASA sponsored partnership between remote sensing scientists, international agencies and NGOs, has developed a new generation of global reef maps based on data collected by satellites. The effort, dubbed the Millennium Coral Reef Map aims to develop new methods for wide distribution of voluminous satellite data of use to the conservation and management communities. We discuss the tradeoffs between remote sensing data sources, mapping objectives, and the needs for conservation and resource management. SeaWiFS data were used to produce a composite global shallow bathymetry map at 1 km resolution. Landsat 7/ETM+ data acquisition plans were modified to collect global reefs and new operational methods were designed to generate the firstever global coral reef geomorphology map. We discuss the challenges encountered to build these databases and in implementing the geospatial data distribution strategies. Conservation applications include a new assessment of the distribution of the world s marine protected areas (UNEPWCMC), improved spatial resolution in the Reefs at Risk analysis for the Caribbean (WRI), and a global basemap for the Census of Marine Life's OBIS database. The Millennium Coral Reef map and digital image archive will pay significant dividends for local and regional conservation projects around the globe. Complete details of the project are available at http://eol.jsc.nasa.gov/reefs.

  2. Lophelia II 2009: Deepwater Program: Exploration and Research of Northern Gulf of Mexico Deepwater Natural and Artificial Hard Bottom Habitats with Emphasis on Coral Communities: Reefs, Rigs and Wrecks on NOAA Ship Ronald H. Brown between 20090819 and 20090912

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This cruise used the remotely operated vehicle (ROV) Jason II to: explore 4-6 new sites for the occurrence of deep water coral reefs; made collections of Lophelia...

  3. Age-Related Shifts in Bacterial Diversity in a Reef Coral.

    Science.gov (United States)

    Williams, Alex D; Brown, Barbara E; Putchim, Lalita; Sweet, Michael J

    2015-01-01

    This study investigated the relationship between microbial communities in differently sized colonies of the massive coral Coelastrea aspera at Phuket, Thailand where colony size could be used as a proxy for age. Results indicated significant differences between the bacterial diversity (ANOSIM, R = 0.76, p = 0.001) of differently sized colonies from the same intertidal reef habitat. Juvenile and small colonies ( 28 cm mean diam). Bacterial diversity increased in a step-wise pattern from juveniles coral skeleton; a result providing some support for the hypothesis that the endolithic algae of corals may directly influence the bacterial community present in coral tissues.

  4. 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.

  5. Divergence of seafloor elevation and sea level rise in coral reef ecosystems

    Science.gov (United States)

    Yates, Kimberly K.; Zawada, David G.; Smiley, Nathan A.; Tiling-Range, Ginger

    2017-01-01

    Coral reefs serve as natural barriers that protect adjacent shorelines from coastal hazards such as storms, waves, and erosion. Projections indicate global degradation of coral reefs due to anthropogenic impacts and climate change will cause a transition to net erosion by mid-century. Here, we provide a comprehensive assessment of the combined effect of all of the processes affecting seafloor accretion and erosion by measuring changes in seafloor elevation and volume for five coral reef ecosystems in the Atlantic, Pacific, and Caribbean over the last several decades. Regional-scale mean elevation and volume losses were observed at all five study sites and in 77 % of the 60 individual habitats that we examined across all study sites. Mean seafloor elevation losses for whole coral reef ecosystems in our study ranged from −0.09 to −0.8 m, corresponding to net volume losses ranging from 3.4  ×  106 to 80.5  ×  106 m3 for all study sites. Erosion of both coral-dominated substrate and non-coral substrate suggests that the current rate of carbonate production is no longer sufficient to support net accretion of coral reefs or adjacent habitats. We show that regional-scale loss of seafloor elevation and volume has accelerated the rate of relative sea level rise in these regions. Current water depths have increased to levels not predicted until near the year 2100, placing these ecosystems and nearby communities at elevated and accelerating risk to coastal hazards. Our results set a new baseline for projecting future impacts to coastal communities resulting from degradation of coral reef systems and associated losses of natural and socioeconomic resources.

  6. 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...

  7. 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.

    are destructive and long-lasting. The coral reef monitoring programme therefore aims at identifying reefs in various localities inorder to monitor them for various diseases and hence evolve strategies to eliminate the causes of diseases...

  8. Wave transformation across coral reefs under changing sea levels

    Science.gov (United States)

    Harris, Daniel; Power, Hannah; Vila-Conejo, Ana; Webster, Jody

    2015-04-01

    The transformation of swell waves from deep water across reef flats is the primary process regulating energy regimes in coral reef systems. Coral reefs are effective barriers removing up to 99% of wave energy during breaking and propagation across reef flats. Consequently back-reef environments are often considered low energy with only limited sediment transport and geomorphic change during modal conditions. Coral reefs, and specifically reef flats, therefore provide important protection to tropical coastlines from coastal erosion and recession. However, changes in sea level could lead to significant changes in the dissipation of swell wave energy in coral reef systems with wave heights dependent on the depth over the reef flat. This suggests that a rise in sea level would also lead to significantly higher energy conditions exacerbating the transgressive effects of sea level rise on tropical beaches and reef islands. This study examines the potential implications of different sea level scenarios on the transformation of waves across the windward reef flats of One Tree Reef, southern Great Barrier Reef. Waves were measured on the reef flats and back-reef sand apron of One Tree Reef. A one-dimensional wave model was calibrated and used to investigate wave processes on the reef flats under different mean sea level (MSL) scenarios (present MSL, +1 m MSL, and +2 m MSL). These scenarios represent both potential future sea level states and also the paleo sea level of the late Holocene in the southern Great Barrier Reef. Wave heights were shown to increase under sea level rise, with greater wave induced orbital velocities affecting the bed under higher sea levels. In general waves were more likely to entrain and transport sediment both on the reef flat and in the back reef environment under higher sea levels which has implications for not only forecasted climate change scenarios but also for interpreting geological changes during the late Holocene when sea levels were 1

  9. Diverse coral communities in mangrove habitats suggest a novel refuge from climate change

    Science.gov (United States)

    Yates, K. K.; Rogers, C. S.; Herlan, J. J.; Brooks, G. R.; Smiley, N. A.; Larson, R. A.

    2014-08-01

    Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business-as-usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH, slows coral growth, and may cause loss of reef structure. Management strategies include establishment of marine protected areas with environmental conditions that promote reef resiliency. However, few resilient reefs have been identified, and resiliency factors are poorly defined. Here we characterize the first natural, non-reef coral refuge from thermal stress and ocean acidification and identify resiliency factors for mangrove-coral habitats. We measured diurnal and seasonal variations in temperature, salinity, photosynthetically active radiation (PAR), and seawater chemistry; characterized substrate parameters; and examined water circulation patterns in mangrove communities where scleractinian corals are growing attached to and under mangrove prop roots in Hurricane Hole, St. John, US Virgin Islands. Additionally, we inventoried the coral species and quantified incidences of coral bleaching, mortality, and recovery for two major reef-building corals, Colpophyllia natans and Diploria labyrinthiformis, growing in mangrove-shaded and exposed (unshaded) areas. Over 30 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR) from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies were living shaded by mangroves, and no shaded colonies were bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies were bleached. A combination of substrate and habitat heterogeneity, proximity of different habitat types, hydrographic

  10. Coral Reef Protection Implementation Plan

    Science.gov (United States)

    2007-11-02

    ecosystems. These reports Caribbean, Gulf of Mexico , and Pacific Ocean." For the will also serve as an awareness tool for agencies to purposes of this report...alternatives for proposed discharges of - 7 dredged or fill material into U.S or international waters, *o SECTION THi- zEE EXISTING FUNDING SOURCES FOR CORAL...facilities on several thousand acres within the Ko’olaupoko Region on O’ahu. Popu- NORTHERN GULF OF MEXICO lation growth and development throughout

  11. Bacterial community composition and potential driving factors in different reef habitats of the Spermonde Archipelago, Indonesia

    DEFF Research Database (Denmark)

    Kegler, Hauke F.; Lukman, Muhammad; Teichberg, Mirta

    2017-01-01

    Coastal eutrophication is a key driver of shifts in bacterial communities on coral reefs. With fringing and patch reefs at varying distances from the coast the Spermonde Archipelago in southern Sulawesi, Indonesia offers ideal conditions to study the effects of coastal eutrophication along...... a spatially defined gradient. The present study investigated bacterial community composition of three coral reef habitats: the water column, sediments, and mucus of the hard coral genus Fungia, along that cross shelf environmental and water quality gradient. The main research questions were: (1) How do water....../Shigella (Gammaproteobacteria) and Raistonia (Betaproteobacteria), respectively, both dominated the bacterial community composition of the both size fractions of the water column and coral mucus. The sampled reef sediments were more diverse, and no single OTUs was dominant. There was no gradual shift in bacterial classes...

  12. Potential Habitat of Acropora spp. on Reefs of Florida, Puerto Rico, and the US Virgin Islands

    OpenAIRE

    Katherine E. Wirt; Pamela Hallock; David Palandro; Kathleen Semon Lunz

    2015-01-01

    Elkhorn and staghorn corals (Acropora palmata, Acropora cervicornis) were listed in 2006 as threatened under the Endangered Species Act. The goal of this study was to create model potential-habitat maps for A. palmata and A. cervicornis, while identifying areas for possible re-establishment. These maps were created using a database of reported field observations in combination with existing benthic habitat maps. The mapped coral reef and hardbottom classifications throughout Florida, Puerto R...

  13. Acanthaster: effect on coral reef growth in panama.

    Science.gov (United States)

    Glynn, P W

    1973-05-04

    Analysis of data on coral abundance and growth, and the population size (26 individuals per hectare) and feeding rate of Acanthaster indicates that Pocillopora reefs on the Pacific coast of Panama are undergoing vigorous growth in the presence of this predator. Prediction of the effects of a population increase in Acanthaster to plague proportions (2.5 times that presently observed) suggests that reefs could still maintain a positive growth. However, Acanthaster at ten times the present population density would lead to rapid destruction of reefs. It is argued that coral destruction due to Acanthaster represents only one of several factors affecting coral reef progression.

  14. 76 FR 38618 - Proposed Information Collection; Comment Request; Coral Reef Conservation Program Survey

    Science.gov (United States)

    2011-07-01

    ... United States (U.S.) jurisdictions containing coral reefs. Specifically, NOAA is seeking information on... collection of social and economic data related to the communities affected by coral reef conservation programs. The Coral Reef Conservation Program (CRCP), developed under the authority of the Coral Reef...

  15. 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... the logbooks is used to obtain fish catch/fishing effort data on coral reef fishes and invertebrates...

  16. Crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes

    KAUST Repository

    Wilson, S. K.

    2010-02-26

    Expert opinion was canvassed to identify crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes. Scientists that had published three or more papers on the effects of climate and environmental factors on reef fishes were invited to submit five questions that, if addressed, would improve our understanding of climate change effects on coral reef fishes. Thirty-three scientists provided 155 questions, and 32 scientists scored these questions in terms of: (i) identifying a knowledge gap, (ii) achievability, (iii) applicability to a broad spectrum of species and reef habitats, and (iv) priority. Forty-two per cent of the questions related to habitat associations and community dynamics of fish, reflecting the established effects and immediate concern relating to climate-induced coral loss and habitat degradation. However, there were also questions on fish demographics, physiology, behaviour and management, all of which could be potentially affected by climate change. Irrespective of their individual expertise and background, scientists scored questions from different topics similarly, suggesting limited bias and recognition of a need for greater interdisciplinary and collaborative research. Presented here are the 53 highest-scoring unique questions. These questions should act as a guide for future research, providing a basis for better assessment and management of climate change impacts on coral reefs and associated fish communities.

  17. Crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes.

    Science.gov (United States)

    Wilson, S K; Adjeroud, M; Bellwood, D R; Berumen, M L; Booth, D; Bozec, Y-Marie; Chabanet, P; Cheal, A; Cinner, J; Depczynski, M; Feary, D A; Gagliano, M; Graham, N A J; Halford, A R; Halpern, B S; Harborne, A R; Hoey, A S; Holbrook, S J; Jones, G P; Kulbiki, M; Letourneur, Y; De Loma, T L; McClanahan, T; McCormick, M I; Meekan, M G; Mumby, P J; Munday, P L; Ohman, M C; Pratchett, M S; Riegl, B; Sano, M; Schmitt, R J; Syms, C

    2010-03-15

    Expert opinion was canvassed to identify crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes. Scientists that had published three or more papers on the effects of climate and environmental factors on reef fishes were invited to submit five questions that, if addressed, would improve our understanding of climate change effects on coral reef fishes. Thirty-three scientists provided 155 questions, and 32 scientists scored these questions in terms of: (i) identifying a knowledge gap, (ii) achievability, (iii) applicability to a broad spectrum of species and reef habitats, and (iv) priority. Forty-two per cent of the questions related to habitat associations and community dynamics of fish, reflecting the established effects and immediate concern relating to climate-induced coral loss and habitat degradation. However, there were also questions on fish demographics, physiology, behaviour and management, all of which could be potentially affected by climate change. Irrespective of their individual expertise and background, scientists scored questions from different topics similarly, suggesting limited bias and recognition of a need for greater interdisciplinary and collaborative research. Presented here are the 53 highest-scoring unique questions. These questions should act as a guide for future research, providing a basis for better assessment and management of climate change impacts on coral reefs and associated fish communities.

  18. 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…

  19. 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.

  20. Herbivore space use influences coral reef recovery

    Science.gov (United States)

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

    2016-01-01

    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

  1. Devising a Coral Reef Ocean Acidification Monitoring Portfolio

    Science.gov (United States)

    Gledhill, D. K.; Jewett, L.

    2012-12-01

    Coral reef monitoring has frequently been based only on descriptive science with limited capacity to assign specific attribution to agents of change. There is a requirement to engineer a diagnostic monitoring approach that can test predictions regarding the response of coral reef ecosystems to ocean acidification, and to identify potential areas of refugia or areas of particular concern. The approach should provide the means to detect not only changes in water chemistry but also changes in coral reef community structure and function which can be anticipated based upon our current understanding of paleo-OA events, experimental findings, process investigations, and modeling projections In August, 2012 a Coral Reef Ocean Acidification Monitoring Portfolio Workshop was hosted by the NOAA Ocean Acidification Program and the National Coral Reef Institute at the Nova Southeastern University Oceanographic Center. The workshop convened researchers and project managers from around the world engaged in coral reef ecosystems ocean acidification monitoring and research. The workshop sought to define a suite of metrics to include as part of long-term coral reef monitoring efforts that can contribute to discerning specific attribution of changes in coral reef ecosystems in response to ocean acidification. This portfolio of observations should leverage existing and proposed monitoring initiatives and would be derived from a suite of chemical, biogeochemical and ecological measurements. This talk will report out on the key findings from the workshop which should include identifying the most valuable that should be integrated into long-term coral reef ecosystem monitoring that will aid in discerning changes in coral reef ecosystems in response to ocean acidification. The outcomes should provide: recommendations of the most efficient and robust ways to monitor these metrics; identified augmentations that would be required to current ocean acidification monitoring necessary to achieve

  2. Selective feeding by coral reef fishes on coral lesions associated with brown band and black band disease

    Science.gov (United States)

    Chong-Seng, K. M.; Cole, A. J.; Pratchett, M. S.; Willis, B. L.

    2011-06-01

    Recent studies have suggested that corallivorous fishes may be vectors for coral disease, but the extent to which fishes actually feed on and thereby potentially transmit coral pathogens is largely unknown. For this study, in situ video observations were used to assess the level to which fishes fed on diseased coral tissues at Lizard Island, northern Great Barrier Reef. Surveys conducted at multiple locations around Lizard Island revealed that coral disease prevalence, especially of brown band disease (BrB), was higher in lagoon and backreef locations than in exposed reef crests. Accordingly, video cameras were deployed in lagoon and backreef habitats to record feeding by fishes during 1-h periods on diseased sections of each of 44 different coral colonies. Twenty-five species from five fish families (Blennidae, Chaetodontidae, Gobiidae, Labridae and Pomacentridae) were observed to feed on infected coral tissues of staghorn species of Acropora that were naturally infected with black band disease (BBD) or brown band disease (BrB). Collectively, these fishes took an average of 18.6 (±5.6 SE) and 14.3 (±6.1 SE) bites per hour from BBD and BrB lesions, respectively. More than 40% (408/948 bites) and nearly 25% (314/1319 bites) of bites were observed on lesions associated with BBD and BrB, respectively, despite these bands each representing only about 1% of the substratum available. Moreover, many corallivorous fishes ( Labrichthys unilineatus, Chaetodon aureofasciatus, C. baronessa, C. lunulatus, C. trifascialis, Cheiloprion labiatus) selectively targeted disease lesions over adjacent healthy coral tissues. These findings highlight the important role that reef fishes may play in the dynamics of coral diseases, either as vectors for the spread of coral disease or in reducing coral disease progression through intensive and selective consumption of diseased coral tissues.

  3. Mangroves enhance the biomass of coral reef fish communities in the Caribbean

    Science.gov (United States)

    Mumby, Peter J.; Edwards, Alasdair J.; Ernesto Arias-González, J.; Lindeman, Kenyon C.; Blackwell, Paul G.; Gall, Angela; Gorczynska, Malgosia I.; Harborne, Alastair R.; Pescod, Claire L.; Renken, Henk; C. C. Wabnitz, Colette; Llewellyn, Ghislane

    2004-02-01

    Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs.

  4. Drivers and predictions of coral reef carbonate budget trajectories

    Science.gov (United States)

    Graham, Nicholas A. J.; Jennings, Simon; Perry, Chris T.

    2017-01-01

    Climate change is one of the greatest threats to the long-term maintenance of coral-dominated tropical ecosystems, and has received considerable attention over the past two decades. Coral bleaching and associated mortality events, which are predicted to become more frequent and intense, can alter the balance of different elements that are responsible for coral reef growth and maintenance. The geomorphic impacts of coral mass mortality have received relatively little attention, particularly questions concerning temporal recovery of reef carbonate production and the factors that promote resilience of reef growth potential. Here, we track the biological carbonate budgets of inner Seychelles reefs from 1994 to 2014, spanning the 1998 global bleaching event when these reefs lost more than 90% of coral cover. All 21 reefs had positive budgets in 1994, but in 2005 budgets were predominantly negative. By 2014, carbonate budgets on seven reefs were comparable with 1994, but on all reefs where an ecological regime shift to macroalgal dominance occurred, budgets remained negative through 2014. Reefs with higher massive coral cover, lower macroalgae cover and lower excavating parrotfish biomass in 1994 were more likely to have positive budgets post-bleaching. If mortality of corals from the 2016 bleaching event is as severe as that of 1998, our predictions based on past trends would suggest that six of eight reefs with positive budgets in 2014 would still have positive budgets by 2030. Our results highlight that reef accretion and framework maintenance cannot be assumed from the ecological state alone, and that managers should focus on conserving aspects of coral reefs that support resilient carbonate budgets. PMID:28123092

  5. Drivers and predictions of coral reef carbonate budget trajectories.

    Science.gov (United States)

    Januchowski-Hartley, Fraser A; Graham, Nicholas A J; Wilson, Shaun K; Jennings, Simon; Perry, Chris T

    2017-01-25

    Climate change is one of the greatest threats to the long-term maintenance of coral-dominated tropical ecosystems, and has received considerable attention over the past two decades. Coral bleaching and associated mortality events, which are predicted to become more frequent and intense, can alter the balance of different elements that are responsible for coral reef growth and maintenance. The geomorphic impacts of coral mass mortality have received relatively little attention, particularly questions concerning temporal recovery of reef carbonate production and the factors that promote resilience of reef growth potential. Here, we track the biological carbonate budgets of inner Seychelles reefs from 1994 to 2014, spanning the 1998 global bleaching event when these reefs lost more than 90% of coral cover. All 21 reefs had positive budgets in 1994, but in 2005 budgets were predominantly negative. By 2014, carbonate budgets on seven reefs were comparable with 1994, but on all reefs where an ecological regime shift to macroalgal dominance occurred, budgets remained negative through 2014. Reefs with higher massive coral cover, lower macroalgae cover and lower excavating parrotfish biomass in 1994 were more likely to have positive budgets post-bleaching. If mortality of corals from the 2016 bleaching event is as severe as that of 1998, our predictions based on past trends would suggest that six of eight reefs with positive budgets in 2014 would still have positive budgets by 2030. Our results highlight that reef accretion and framework maintenance cannot be assumed from the ecological state alone, and that managers should focus on conserving aspects of coral reefs that support resilient carbonate budgets. © 2017 The Authors.

  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.; P. A. Todd; T. C. Toh; 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. Coral community response to bleaching on a highly disturbed reef

    OpenAIRE

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

    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:...

  8. Climate change impacts on freshwater fish, coral reefs, and related ecosystem services in the United States

    Science.gov (United States)

    We analyzed the potential physical and economic impacts of climate change on freshwater fisheries and coral reefs in the United States, examining a reference scenario and two policy scenarios that limit global greenhouse gas (GHG) emissions. We modeled shifts in suitable habitat ...

  9. Habitat Selectivity and Reliance on Live Corals for Indo-Pacific Hawkfishes (Family: Cirrhitidae)

    KAUST Repository

    Coker, Darren James

    2015-11-03

    Hawkfishes (family: Cirrhitidae) are small conspicuous reef predators that commonly perch on, or shelter within, the branches of coral colonies. This study examined habitat associations of hawkfishes, and explicitly tested whether hawkfishes associate with specific types of live coral. Live coral use and habitat selectivity of hawkfishes was explored at six locations from Chagos in the central Indian Ocean extending east to Fiji in the Pacific Ocean. A total of 529 hawkfishes from seven species were recorded across all locations with 63% of individuals observed perching on, or sheltering within, live coral colonies. Five species (all except Cirrhitus pinnulatus and Cirrhitichthys oxycephalus) associated with live coral habitats. Cirrhitichthys falco selected for species of Pocillopora while Paracirrhites arcatus and P. forsteri selected for both Pocillopora and Acropora, revealing that these habitats are used disproportionately more than expected based on the local cover of these coral genera. Habitat selection was consistent across geographic locations, and species of Pocillopora were the most frequently used and most consistently selected even though this coral genus never comprised more than 6% of the total coral cover at any of the locations. Across locations, Paracirrhites arcatus and P. forsteri were the most abundant species and variation in their abundance corresponded with local patterns of live coral cover and abundance of Pocilloporid corals, respectively. These findings demonstrate the link between small predatory fishes and live coral habitats adding to the growing body of literature highlighting that live corals (especially erect branching corals) are critically important for sustaining high abundance and diversity of fishes on coral reefs.

  10. Environmental quality and preservation; reefs, corals, and carbonate sands; guides to reef-ecosystem health and environment

    Science.gov (United States)

    Lidz, Barbara H.

    2001-01-01

    Introduction In recent years, the health of the entire coral reef ecosystem that lines the outer shelf off the Florida Keys has declined markedly. In particular, loss of those coral species that are the building blocks of solid reef framework has significant negative implications for economic vitality of the region. What are the reasons for this decline? Is it due to natural change, or are human activities (recreational diving, ship groundings, farmland runoff, nutrient influx, air-borne contaminants, groundwater pollutants) a contributing factor and if so, to what extent? At risk of loss are biologic resources of the reefs, including habitats for endangered species in shoreline mangroves, productive marine and wetland nurseries, and economic fisheries. A healthy reef ecosystem builds a protective offshore barrier to catastrophic wave action and storm surges generated by tropical storms and hurricanes. In turn, a healthy reef protects the homes, marinas, and infrastructure on the Florida Keys that have been designed to capture a lucrative tourism industry. A healthy reef ecosystem also protects inland agricultural and livestock areas of South Florida whose produce and meat feed much of the United States and other parts of the world. In cooperation with the National Oceanic and Atmospheric Administration's (NOAA) National Marine Sanctuary Program, the U.S. Geological Survey (USGS) continues longterm investigations of factors that may affect Florida's reefs. One of the first steps in distinguishing between natural change and the effects of human activities, however, is to determine how coral reefs have responded to past environmental change, before the advent of man. By so doing, accurate scientific information becomes available for Marine Sanctuary management to understand natural change and thus to assess and regulate potential human impact better. The USGS studies described here evaluate the distribution (location) and historic vitality (thickness) of Holocene

  11. Could some coral reefs become sponge reefs as our climate changes?

    Science.gov (United States)

    Bell, James J; Davy, Simon K; Jones, Timothy; Taylor, Michael W; Webster, Nicole S

    2013-09-01

    Coral reefs across the world have been seriously degraded and have a bleak future in response to predicted global warming and ocean acidification (OA). However, this is not the first time that biocalcifying organisms, including corals, have faced the threat of extinction. The end-Triassic mass extinction (200 million years ago) was the most severe biotic crisis experienced by modern marine invertebrates, which selected against biocalcifiers; this was followed by the proliferation of another invertebrate group, sponges. The duration of this sponge-dominated period far surpasses that of alternative stable-ecosystem or phase-shift states reported on modern day coral reefs and, as such, a shift to sponge-dominated reefs warrants serious consideration as one future trajectory of coral reefs. We hypothesise that some coral reefs of today may become sponge reefs in the future, as sponges and corals respond differently to changing ocean chemistry and environmental conditions. To support this hypothesis, we discuss: (i) the presence of sponge reefs in the geological record; (ii) reported shifts from coral- to sponge-dominated systems; and (iii) direct and indirect responses of the sponge holobiont and its constituent parts (host and symbionts) to changes in temperature and pH. Based on this evidence, we propose that sponges may be one group to benefit from projected climate change and ocean acidification scenarios, and that increased sponge abundance represents a possible future trajectory for some coral reefs, which would have important implications for overall reef functioning. © 2013 John Wiley & Sons Ltd.

  12. 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

  13. Elevated Colonization of Microborers at a Volcanically Acidified Coral Reef

    Science.gov (United States)

    Enochs, Ian C.; Manzello, Derek P.; Tribollet, Aline; Valentino, Lauren; Kolodziej, Graham; Donham, Emily M.; Fitchett, Mark D.; Carlton, Renee; Price, Nichole N.

    2016-01-01

    Experiments have demonstrated that ocean acidification (OA) conditions projected to occur by the end of the century will slow the calcification of numerous coral species and accelerate the biological erosion of reef habitats (bioerosion). Microborers, which bore holes less than 100 μm diameter, are one of the most pervasive agents of bioerosion and are present throughout all calcium carbonate substrates within the reef environment. The response of diverse reef functional groups to OA is known from real-world ecosystems, but to date our understanding of the relationship between ocean pH and carbonate dissolution by microborers is limited to controlled laboratory experiments. Here we examine the settlement of microborers to pure mineral calcium carbonate substrates (calcite) along a natural pH gradient at a volcanically acidified reef at Maug, Commonwealth of the Northern Mariana Islands (CNMI). Colonization of pioneer microborers was higher in the lower pH waters near the vent field. Depth of microborer penetration was highly variable both among and within sites (4.2–195.5 μm) over the short duration of the study (3 mo.) and no clear relationship to increasing CO2 was observed. Calculated rates of biogenic dissolution, however, were highest at the two sites closer to the vent and were not significantly different from each other. These data represent the first evidence of OA-enhancement of microboring flora colonization in newly available substrates and provide further evidence that microborers, especially bioeroding chlorophytes, respond positively to low pH. The accelerated breakdown and dissolution of reef framework structures with OA will likely lead to declines in structural complexity and integrity, as well as possible loss of essential habitat. PMID:27467570

  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.

    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

  16. 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

  17. Do tabular corals constitute keystone structures for fishes on coral reefs?

    Science.gov (United States)

    Kerry, J. T.; Bellwood, D. R.

    2015-03-01

    This study examined the changes in community composition of reef fishes by experimentally manipulating the availability of shelter provided by tabular structures on a mid-shelf reef on the Great Barrier Reef. At locations where access to tabular corals ( Acropora hyacinthus and Acropora cytherea) was excluded, a rapid and sustained reduction in the abundance of large reef fishes occurred. At locations where tabular structure was added, the abundance and diversity of large reef fishes increased and the abundance of small reef fishes tended to decrease, although over a longer time frame. Based on their response to changes in the availability of tabular structures, nine families of large reef fishes were separated into three categories; designated as obligate, facultative or non-structure users. This relationship may relate to the particular ecological demands of each family, including avoidance of predation and ultraviolet radiation, access to feeding areas and reef navigation. This study highlights the importance of tabular corals for large reef fishes in shallow reef environments and provides a possible mechanism for local changes in the abundance of reef fishes following loss of structural complexity on coral reefs. Keystone structures have a distinct structure and disproportionate effect on their ecosystem relative to their abundance, as such the result of this study suggests tabular corals may constitute keystone structures on shallow coral reefs.

  18. Understanding coral reefs in an impacted world: Physiological responses of coral reef organisms to coastal pollution and global warming

    OpenAIRE

    Kegler, Pia

    2015-01-01

    Coral reefs are facing a multitude of anthropogenic disturbances at ever higher frequencies and magnitudes. As a consequence, these ecologically and economically important ecosystems are degrading worldwide. Reef managers lack knowledge on how fish, corals and coral larvae respond to the effects of local and global stressors. This thesis reveals the significance of chemical pollution from localized sources. Two common pollutants (diesel and a surfactant) caused metabolic changes in a fish and...

  19. Community structure of coral reefs on opposite sides of the isthmus of panama.

    Science.gov (United States)

    Portfr, J W

    1974-11-08

    Competition for space amon reef corals includes interspecific destruction by extracoelenteric digestion., rapid growth. and Overtopping. No Caribbean species excela in all strategies, and on western Caribbean coral reefs there is a positive correlation between coral abudance and diversity. On eastern Pacific coral reefs, however. Pocillopora damicornis excludes other corals, and on these reefs there is an inverse relation between coral abundance and diversity, except in areas where distrubances, such as Acanthaster predation offset space monopolization.

  20. Local extinction of a coral reef fish explained by inflexible prey choice

    Science.gov (United States)

    Brooker, R. M.; Munday, P. L.; Brandl, S. J.; Jones, G. P.

    2014-12-01

    While global extinctions of marine species are infrequent, local extinctions are becoming common. However, the role of habitat degradation and resource specialisation in explaining local extinction is unknown. On coral reefs, coral bleaching is an increasingly frequent cause of coral mortality that can result in dramatic changes to coral community composition. Coral-associated fishes are often specialised on a limited suite of coral species and are therefore sensitive to these changes. This study documents the local extinction of a corallivorous reef fish, Oxymonacanthus longirostris, following a mass bleaching event that altered the species composition of associated coral communities. Local extinction only occurred on reefs that also completely lost a key prey species, Acropora millepora, even though coral cover remained high. In an experimental test, fish continued to select bleached A. millepora over the healthy, but less-preferred prey species that resisted bleaching. These results suggest that behavioural inflexibility may limit the ability of specialists to cope with even subtle changes to resource availability.

  1. Physiology can contribute to better understanding, management, and conservation of coral reef fishes.

    Science.gov (United States)

    Illing, Björn; Rummer, Jodie L

    2017-01-01

    Coral reef fishes, like many other marine organisms, are affected by anthropogenic stressors such as fishing and pollution and, owing to climate change, are experiencing increasing water temperatures and ocean acidification. Against the backdrop of these various stressors, a mechanistic understanding of processes governing individual organismal performance is the first step for identifying drivers of coral reef fish population dynamics. In fact, physiological measurements can help to reveal potential cause-and-effect relationships and enable physiologists to advise conservation management by upscaling results from cellular and individual organismal levels to population levels. Here, we highlight studies that include physiological measurements of coral reef fishes and those that give advice for their conservation. A literature search using combined physiological, conservation and coral reef fish key words resulted in ~1900 studies, of which only 99 matched predefined requirements. We observed that, over the last 20 years, the combination of physiological and conservation aspects in studies on coral reef fishes has received increased attention. Most of the selected studies made their physiological observations at the whole organism level and used their findings to give conservation advice on population dynamics, habitat use or the potential effects of climate change. The precision of the recommendations differed greatly and, not surprisingly, was least concrete when studies examined the effects of projected climate change scenarios. Although more and more physiological studies on coral reef fishes include conservation aspects, there is still a lack of concrete advice for conservation managers, with only very few published examples of physiological findings leading to improved management practices. We conclude with a call to action to foster better knowledge exchange between natural scientists and conservation managers to translate physiological findings more

  2. 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

    2016-01-07

    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.

  3. National Coral Reef Monitoring Program: Assessment of coral reef communities in U.S. Virgin Islands (USVI) using the Coral Demographics method

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Coral Demographics method is one of two benthic surveys conducted in the U.S. Virgin Islands (USVI) as part of the National Coral Reef Monitoring Program...

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    Heidi M Luter

    Full Text Available 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 <5% of each tile. In contrast, mean abundances of sponges, ascidians, algae, and bryozoans combined was generally less than 20% of total recruitment, with percentage cover ranging between 15-30% per tile. Coral recruitment was very low, with <1 recruit per tile identified. A hierarchal analysis of variation over a range of spatial and temporal scales showed significant spatio-temporal variation in recruitment patterns, but the highest variability occurred at the lowest spatial scale examined (1 m-among tiles. Temporal variability in recruitment of both numbers of taxa and percentage cover was also evident across both summer and winter. Recruitment across depth varied for some taxonomic groups like algae, sponges and ascidians, with greatest differences in summer. This study presents some of the first data on benthic recruitment within the northern GBR and provides a greater understanding of population ecology for coral reefs.

  6. Climate change and coral reef bleaching: An ecological assessment of long-term impacts, recovery trends and future outlook

    Science.gov (United States)

    Baker, Andrew C.; Glynn, Peter W.; Riegl, Bernhard

    2008-12-01

    Since the early 1980s, episodes of coral reef bleaching and mortality, due primarily to climate-induced ocean warming, have occurred almost annually in one or more of the world's tropical or subtropical seas. Bleaching is episodic, with the most severe events typically accompanying coupled ocean-atmosphere phenomena, such as the El Niño-Southern Oscillation (ENSO), which result in sustained regional elevations of ocean temperature. Using this extended dataset (25+ years), we review the short- and long-term ecological impacts of coral bleaching on reef ecosystems, and quantitatively synthesize recovery data worldwide. Bleaching episodes have resulted in catastrophic loss of coral cover in some locations, and have changed coral community structure in many others, with a potentially critical influence on the maintenance of biodiversity in the marine tropics. Bleaching has also set the stage for other declines in reef health, such as increases in coral diseases, the breakdown of reef framework by bioeroders, and the loss of critical habitat for associated reef fishes and other biota. Secondary ecological effects, such as the concentration of predators on remnant surviving coral populations, have also accelerated the pace of decline in some areas. Although bleaching severity and recovery have been variable across all spatial scales, some reefs have experienced relatively rapid recovery from severe bleaching impacts. There has been a significant overall recovery of coral cover in the Indian Ocean, where many reefs were devastated by a single large bleaching event in 1998. In contrast, coral cover on western Atlantic reefs has generally continued to decline in response to multiple smaller bleaching events and a diverse set of chronic secondary stressors. No clear trends are apparent in the eastern Pacific, the central-southern-western Pacific or the Arabian Gulf, where some reefs are recovering and others are not. The majority of survivors and new recruits on

  7. Coral diseases and bleaching on Colombian Caribbean coral reefs

    Directory of Open Access Journals (Sweden)

    Raúl Navas-Camacho

    2010-05-01

    Full Text Available Since 1998 the National Monitoring System for the Coral Reefs of Colombia (SIMAC has monitored the occurrence of coral bleaching and diseases in some Colombian coral reefs (permanent stations at San Andres Island, Rosario Islands, Tayrona, San Bernardo Islands and Urabá. The main purpose is to evaluate their health status and to understand the factors that have been contributing to their decline. To estimate these occurrences, annual surveys in 126 permanent belt transects (10x2m with different depth intervals (3-6 meters, 9-12 meters and 15-18 meters are performed at all reef sites. Data from the 1998-2004 period, revealed that San Andrés Island had many colonies with diseases (38.9 colonies/m2, and Urabá had high numbers with bleaching (54.4 colonies/m2. Of the seven reported coral diseases studied, Dark Spots Disease (DSD, and White Plague Disease (WPD were noteworthy because they occurred in all Caribbean monitored sites, and because of their high interannual infection incidence. Thirty five species of scleractinian corals were affected by at least one disease and a high incidence of coral diseases on the main reef builders is documented. Bleaching was present in 34 species. During the whole monitoring period, Agaricia agaricites and Siderastrea siderea were the species most severely affected by DSD and bleaching, respectively. Diseases on species such as Agaricia fragilis, A.grahamae, A. humilis, Diploria clivosa, Eusmilia fastigiata, Millepora complanata, and Mycetophyllia aliciae are recorded for first time in Colombia. We present bleaching and disease incidences, kinds of diseases, coral species affected, reef localities studied, depth intervals of surveys, and temporal (years variation for each geographic area. This variation makes difficult to clearly determine defined patterns or general trends for monitored reefs. This is the first long-term study of coral diseases and bleaching in the Southwestern Caribbean, and one of the few

  8. 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

    2013-04-05

    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.

  9. 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.

  10. Status and conservation of coral reefs in Costa Rica.

    Science.gov (United States)

    Cortés, Jorge; Jiménez, Carlos E; Fonseca, Ana C; Alvarado, Juan José

    2010-05-01

    Costa Rica has coral communities and reefs on the Caribbean coast and on the Pacific along the coast and off-shore islands. The Southern section of the Caribbean coast has fringing and patch reefs, carbonate banks, and an incipient algal ridge. The Pacific coast has coral communities, reefs and isolated coral colonies. Coral reefs have been seriously impacted in the last 30 years, mainly by sediments (Caribbean coast and some Pacific reefs) and by El Niño warming events (both coasts). Monitoring is being carried out at three sites on each coast. Both coasts suffered significant reductions in live coral cover in the 1980's, but coral cover is now increasing in most sites. The government of Costa Rica is aware of the importance of coral reefs and marine environments in general, and in recent years decrees have been implemented (or are in the process of approval) to protect them, but limited resources endanger their proper management and conservation, including proper outreach to reef users and the general public.

  11. Unseen players shape benthic competition on coral reefs.

    Science.gov (United States)

    Barott, Katie L; Rohwer, Forest L

    2012-12-01

    Recent work has shown that hydrophilic and hydrophobic organic matter (OM) from algae disrupts the function of the coral holobiont and promotes the invasion of opportunistic pathogens, leading to coral morbidity and mortality. Here we refer to these dynamics as the (3)DAM [dissolved organic matter (DOM), direct contact, disease, algae and microbes] model. There is considerable complexity in coral-algae interactions; turf algae and macroalgae promote heterotrophic microbial overgrowth of coral, macroalgae also directly harm the corals via hydrophobic OM, whereas crustose coralline algae generally encourage benign microbial communities. In addition, complex flow patterns transport OM and pathogens from algae to downstream corals, and direct algal contact enhances their delivery. These invisible players (microbes, viruses, and OM) are important drivers of coral reefs because they have non-linear responses to disturbances and are the first to change in response to perturbations, providing near real-time trajectories for a coral reef, a vital metric for conservation and restoration.

  12. Phase shift from a coral to a corallimorph-dominated reef associated with a shipwreck on Palmyra atoll.

    Science.gov (United States)

    Work, Thierry M; Aeby, Greta S; Maragos, James E

    2008-08-20

    Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Various reasons have been proposed to explain this phenomenon including increased human disturbance, pollution, or changes in coral reef biota that serve a major ecological function such as depletion of grazers. However, pinpointing the actual factors potentially responsible can be problematic. Here we show a phase shift from coral to the corallimorpharian Rhodactis howesii associated with a long line vessel that wrecked in 1991 on an isolated atoll (Palmyra) in the central Pacific Ocean. We documented high densities of R. howesii near the ship that progressively decreased with distance from the ship whereas R. howesii were rare to absent in other parts of the atoll. We also confirmed high densities of R. howesii around several buoys recently installed on the atoll in 2001. This is the first time that a phase shift on a coral reef has been unambiguously associated with man-made structures. This association was made, in part, because of the remoteness of Palmyra and its recent history of minimal human habitation or impact. Phase shifts can have long-term negative ramification for coral reefs, and eradication of organisms responsible for phase shifts in marine ecosystems can be difficult, particularly if such organisms cover a large area. The extensive R. howesii invasion and subsequent loss of coral reef habitat at Palmyra also highlights the importance of rapid removal of shipwrecks on corals reefs to mitigate the potential of reef overgrowth by invasives.

  13. A trait-based approach to advance coral reef science

    DEFF Research Database (Denmark)

    Madin, Joshua S.; Hoogenboom, Mia O.; Connolly, Sean R.

    2016-01-01

    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...... 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....

  14. Comparison of Commercial Structure-From Photogrammety Software Used for Underwater Three-Dimensional Modeling of Coral Reef Environments

    Science.gov (United States)

    Burns, J. H. R.; Delparte, D.

    2017-02-01

    Structural complexity in ecosystems creates an assortment of microhabitat types and has been shown to support greater diversity and abundance of associated organisms. The 3D structure of an environment also directly affects important ecological parameters such as habitat provisioning and light availability and can therefore strongly influence ecosystem function. Coral reefs are architecturally complex 3D habitats, whose structure is intrinsically linked to the ecosystem biodiversity, productivity, and function. The field of coral ecology has, however, been primarily limited to using 2-dimensional (2D) planar survey techniques for studying the physical structure of reefs. This conventional approach fails to capture or quantify the intricate structural complexity of corals that influences habitat facilitation and biodiversity. A 3-dimensional (3D) approach can obtain accurate measurements of architectural complexity, topography, rugosity, volume, and other structural characteristics that affect biodiversity and abundance of reef organisms. Structurefrom- Motion (SfM) photogrammetry is an emerging computer vision technology that provides a simple and cost-effective method for 3D reconstruction of natural environments. SfM has been used in several studies to investigate the relationship between habitat complexity and ecological processes in coral reef ecosystems. This study compared two commercial SfM software packages, Agisoft Photoscan Pro and Pix4Dmapper Pro 3.1, in order to assess the cpaability and spatial accuracy of these programs for conducting 3D modeling of coral reef habitats at three spatial scales.

  15. The status of coral reefs and associated fishes and invertebrates of commercial importance in Pedro Bank, Jamaica

    Directory of Open Access Journals (Sweden)

    Andrew W. Bruckner

    2014-09-01

    Full Text Available The coral reefs located off the north coast of the Jamaican mainland are some of the best and most studied reefs in the world. Coral reefs of Pedro Bank, Jamaica were assessed in March, 2012 as part of the KSLOF Global Reef Expedition using a modified Atlantic and Gulf Rapid Reef Assessment (AGRRA protocol. The main objectives were to: 1 characterize the distribution, structure and health of coral reefs; and 2 evaluate the population status of commercially important reef fishes and invertebrates. This work was conducted to assist in characterizing coral reef habitats within and outside a proposed fishery reserve, and identify other possible conservation zones. Within 20 reefs, live coral cover ranged from 4.9% to 19.2%. Coral communities were dominated by small corals (esp. Agaricia, Porites and Siderastrea although many sites had high abundances of large colonies of Montastraea annularis and M. faveolata, and these were generally in good condition. A single area, within the proposed fishery reserve, had extensive Acropora cervicornis thickets, and several shallow locations had small, but recovering A. palmata stands. Macroalgal cover at all sites was relatively low, with only three sites having greater than 30% cover; crustose coralline algae (CCA was high, with eight sites exceeding 20% cover. Fish biomass at all sites near the Cays was low, with a dominance of herbivores (parrotfish and surgeonfish and a near absence of groupers, snappers and other commercially important species. While parrotfish were the most abundant fish, these were all extremely small (mean size= 12cm; <4% over 29cm, and they were dominated by red band parrotfish (Sparisoma aurofrenatum followed by striped parrotfish (Scarus iseri. While coral communities remain in better condition than most coastal reefs in Jamaica, intense fishing pressure using fish traps (main target species: surgeonfish and hookah/spear fishing (main target: parrotfish is of grave concern to the

  16. Coral reef diseases in the Atlantic-Caribbean

    Science.gov (United States)

    Rogers, Caroline S.; Weil, Ernesto; Dubinsky, Zvy; Stambler, Noga

    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.

  17. 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

  18. 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

  19. 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

  20. 77 FR 32572 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the...

    Science.gov (United States)

    2012-06-01

    ..., and South Atlantic; Coral and Coral Reefs Off the Southern Atlantic States; Exempted Fishing Permit... South Carolina Aquarium to collect, with certain conditions, various species of reef fish, crabs, and...

  1. 76 FR 41764 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs off the...

    Science.gov (United States)

    2011-07-15

    ... Atlantic; Coral and Coral Reefs off the Southern Atlantic States; Exempted Fishing Permit AGENCY: National... artificial reefs without additional authorization. A report on the project findings is due at the end of the...

  2. Considering Species Tolerance to Climate Change in Conservation Management at Little Cayman's Coral Reefs

    Science.gov (United States)

    Camp, E.; Manfrino, C.; Smith, D.; Suggett, D.

    2013-05-01

    There is growing evidence demonstrating that climate change, notably increased frequency and intensity of thermal anomalies combined with ocean acidification, will negatively impact the future growth and viability of many reef systems, including those in the Caribbean. One key question that remains unanswered is whether or not there are management options aimed at protecting coral species from these threats. Little Cayman (Cayman Islands) provides a rare opportunity to investigate global climate stressors without the confounding impact of local anthropogenic stressors. Our research has focused on two climate change issues: Firstly, we have identified species-specific coral bleaching susceptibility (and the influence of regulation upon this susceptibility) to thermal anomalies. Species level of vulnerability to thermal anomalies can decrease when grown under variable temperature. Environmental variability may be key in influencing the susceptibility of corals to stress. The second part of our research has therefore addressed the variability in inorganic carbon chemistry that naturally occurs where certain reef building corals exist. We have identified how the inorganic carbon chemistry varies naturally among habitats and thus how corals within these habitats are potentially adapted to future acidification. Spatial, diurnal, lunar and seasonal variability have been identified as important factors with pCO2 values of up to 700-800 μatm and pH values as low as 7.801 for lagoon habitats, showing that some species are already being exposed to typical pCO2 and pH levels expected for the oceans in ~50 years' time. Using an eco-physiological approach, we are exploring how some reef-building corals are able to acclimate to more variable chemistry compared to others and whether this natural capacity installs increased tolerance to future acidification. These eco-physiological studies provide important information that can be utilized in a management framework. The aim of

  3. Hurricanes, coral reefs and rainforests: resistance, ruin and recovery in the Caribbean

    Science.gov (United States)

    2000-01-01

    The coexistence of hurricanes, coral reefs, and rainforests in the Caribbean demonstrates that highly structured ecosystems with great diversity can flourish in spite of recurring exposure to intense destructive energy. Coral reefs develop in response to wave energy and resist hurricanes largely by virtue of their structural strength. Limited fetch also protects some reefs from fully developed hurricane waves. While storms may produce dramatic local reef damage, they appear to have little impact on the ability of coral reefs to provide food or habitat for fish and other animals. Rainforests experience an enormous increase in wind energy during hurricanes with dramatic structural changes in the vegetation. The resulting changes in forest microclimate are larger than those on reefs and the loss of fruit, leaves, cover, and microclimate has a great impact on animal populations. Recovery of many aspects of rainforest structure and function is rapid, though there may be long-term changes in species composition. While resistance and repair have maintained reefs and rainforests in the past, human impacts may threaten their ability to survive.

  4. 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. © 2012 Blackwell Publishing Ltd/CNRS.

  5. Estimating the role of three mesopredatory fishes in coral reef food webs at Ningaloo Reef, Western Australia

    Science.gov (United States)

    Thillainath, Emma C.; McIlwain, Jennifer L.; Wilson, Shaun K.; Depczynski, Martial

    2016-03-01

    Within the complex food webs that occur on coral reefs, mesopredatory fish consume small-bodied prey and transfer accumulated biomass to other trophic levels. We estimated biomass, growth and mortality rates of three common mesopredators from Ningaloo Reef in Western Australia to calculate their annual turnover rates and potential contribution to local trophic dynamics. Biomass estimates of the serranid Epinephelus rivulatus (4.46 ± 0.76 g m-2) were an order of magnitude greater than two smaller-bodied mesopredatory fishes, Pseudochromis fuscus (0.10 ± 0.03 g m-2) and Parapercis clathrata (0.23 ± 0.31 g m-2). Growth parameters generated from a von Bertalanffy growth function fitted to size-at-age data, however, indicated that mortality rates for the three mesopredators were similar and that 32-55 % of fish survived each year. Consequently, interspecific differences in annual turnover rates among E. rivulatus (1.9 g m-2 yr-1), Pa. clathrata (0.10 g m-2 yr-1) and Ps. fuscus (0.07 g m-2 yr-1) were an artefact of differences in local biomass estimates. The rapid turnover estimates for E. rivulatus suggest this species is an important conduit of energy within the isolated patch reef habitat where it is typically found, while Ps. fuscus and Pa. clathrata channel smaller amounts of energy from specific habitats in the Ningaloo lagoon. Apparent differences in habitat, diet and turnover rates of the three species examined provide an insight into the different roles these species play in coral reef food webs and suggest that life-history traits allow for variability in the local and spatial contribution of these species at Ningaloo Reef. Moreover, calculating turnover rates of a broader suite of fish species from a range of trophic groups will help better define the role of fishes in coral reef trophic dynamics.

  6. Microbial to reef scale interactions between the reef-building coral Montastraea annularis and benthic algae

    NARCIS (Netherlands)

    Barott, K.L.; Rodriguez-Mueller, B; Youle, M.; Marhaver, K.L.; Vermeij, M.J.A.; Smith, J.E.; Rohwer, F.L.

    2012-01-01

    Competition between reef-building corals and benthic algae is of key importance for reef dynamics. These interactions occur on many spatial scales, ranging from chemical to regional. Using microprobes, 16S rDNA pyrosequencing and underwater surveys, we examined the interactions between the reef-buil

  7. Mapping seagrass beds and coral reefs in the coastal region of Vietnam using VNREDSAT-1 data

    Science.gov (United States)

    Lau, K. V.; Chen, C. F.; Nguyen, S. T.; Chen, C. R.; Tong Phuoc, H. S.; Nguyen, H. H.

    2015-12-01

    Seagrass beds and coral reefs are two important ecosystems in the coastal zone. They play an important role to protect and shelter various marine organisms. Both seagrass beds and coral reefs could prevent the coastline from erosion. While seagrass stabilizes sediments and acts as a biofilter, coral reefs can control carbon dioxide in the ocean water. Besides, seagrass also provides direct food for many fish and marine animals. Therefore, mapping seagrass beds and coral reefs is very important for coastal management and conservation. In May 2013, Vietnam launched the first satellite for earth observations, called Vietnam Natural Resources, Environment and Disaster Monitoring Satellite (VNREDSAT-1). It is a great opportunity for environmental monitoring in the country using the data from this satellite. The objective of this study is to use the VNREDSAT-1 data to map seagrass beds and coral reefs in the coastal region of Ninh Hai district, Ninh Thuan province, Vietnam, where the seagrass still remains in good a condition. We processed the VNREDSAT-1 image through four steps: (1) Atmospheric correction using Second Simulation of the Satellite Signal in the Solar Spectrum radiative transfer model (6S), (2) Sun glint removal by using Hedley method, (3) Water column correction using the depth-variant index (DII) proposed by Lyzenga, and (4) Image classification using the maximum likelihood algorithm. The mapping results verified with the ground reference data showed a good overall accuracy of 75% and Kappa coefficient of 0.7. The total area of seagrass beds was approximately 323.09 ha, which mainly distributed in My Hoa and Thai An villages. The total area of coral reefs was approximately 564.42 ha, located along the coast and on outer area to seagrass and shoreline reefs. This study demonstrates the applicability of VNREDSAT-1 for underwater habitat monitoring. The results could be useful for natural resources managers to devise strategies for management and

  8. 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...

  9. 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...

  10. Spatial and temporal patterns of coral bleaching around Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands [poster

    OpenAIRE

    Clark, Randall D.; Jeffrey, Christopher F. G.; Woody, Kimberly; Hillis-Starr, Zandy

    2008-01-01

    Limited information currently exists on the recovery periods of bleached corals as well as the spatial extent, causative factors, and the overall impact of bleaching on coral reef ecosystems. During October, 2005, widespread coral bleaching was observed within Buck Island Reef National Monument (BUIS) St. Croix, USVI. The bleaching event was preceded by 10 weeks of higher than average water temperatures (28.9-30.1°C). Random transects (100 square meters) over hard bottom habitats (N=94) revea...

  11. Spatial and temporal patterns of coral bleaching around Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands [poster

    OpenAIRE

    Randall D Clark; Jeffrey, Christopher F. G.; Woody, Kimberly; Hillis-Starr, Zandy

    2008-01-01

    Limited information currently exists on the recovery periods of bleached corals as well as the spatial extent, causative factors, and the overall impact of bleaching on coral reef ecosystems. During October, 2005, widespread coral bleaching was observed within Buck Island Reef National Monument (BUIS) St. Croix, USVI. The bleaching event was preceded by 10 weeks of higher than average water temperatures (28.9-30.1°C). Random transects (100 square meters) over hard bottom habitats (N=94) revea...

  12. Ecological limitations to the resilience of coral reefs

    Science.gov (United States)

    Mora, Camilo; Graham, Nicholas A. J.; Nyström, Magnus

    2016-12-01

    The decline of coral reefs has been broadly attributed to human stressors being too strong and pervasive, whereas biological processes that may render coral reefs fragile have been sparsely considered. Here we review several ecological factors that can limit the ability of coral reefs to withstand disturbance. These include: (1) Many species lack the adaptive capacity to cope with the unprecedented disturbances they currently face; (2) human disturbances impact vulnerable life history stages, reducing reproductive output and the supply of recruits essential for recovery; (3) reefs can be vulnerable to the loss of few species, as niche specialization or temporal and spatial segregation makes each species unique (i.e., narrow ecological redundancy); in addition, many foundation species have similar sensitivity to disturbances, suggesting that entire functions can be lost to single disturbances; and (4) feedback loops and extinction vortices may stabilize degraded states or accelerate collapses even if stressors are removed. This review suggests that the degradation of coral reefs is due to not only the severity of human stressors but also the "fragility" of coral reefs. As such, appropriate governance is essential to manage stressors while being inclusive of ecological process and human uses across transnational scales. This is a considerable but necessary upgrade in current management if the integrity, and delivery of goods and services, of coral reefs is to be preserved.

  13. Low calcification in corals in the Great Barrier Reef

    Science.gov (United States)

    Bhattacharya, Atreyee

    2012-10-01

    Reef-building coral communities in the Great Barrier Reef—the world's largest coral reef—may now be calcifying at only about half the rate that they did during the 1970s, even though live coral cover may not have changed over the past 40 years, a new study finds. In recent decades, coral reefs around the world, home to large numbers of fish and other marine species, have been threatened by such human activities as pollution, overfishing, global warming, and ocean acidification; the latter affects ambient water chemistry and availability of calcium ions, which are critical for coral communities to calcify, build, and maintain reefs. Comparing data from reef surveys during the 1970s, 1980s, and 1990s with present-day (2009) measurements of calcification rates in One Tree Island, a coral reef covering 13 square kilometers in the southern part of the Great Barrier Reef, Silverman et al. show that the total calcification rates (the rate of calcification minus the rate of dissolution) in these coral communities have decreased by 44% over the past 40 years; the decrease appears to stem from a threefold reduction in calcification rates during nighttime.

  14. 76 FR 63904 - Proposed Information Collection; Comment Request; Coral Reef Conservation Program Administration

    Science.gov (United States)

    2011-10-14

    ..., extension 150, or Jenny.Waddell@noaagov. SUPPLEMENTARY INFORMATION: I. Abstract The Coral Reef Conservation... reef conservation to conduct activities to protect and conserve coral reef ecosystems. The information...) if a proposed project is consistent with the coral reef conservation priorities of authorities...

  15. Coral health on reefs near mining sites in New Caledonia.

    Science.gov (United States)

    Heintz, T; Haapkylä, J; Gilbert, A

    2015-07-23

    Coral health data are poorly documented in New Caledonia, particularly from reefs chronically subject to anthropogenic and natural runoff. We investigated patterns of coral disease and non-disease conditions on reefs situated downstream of mining sites off the coast of New Caledonia. Surveys were conducted in March 2013 at 2 locations along the west coast and 2 locations along the east coast of the main island. Only 2 coral diseases were detected: growth anomalies and white syndrome. The most prevalent signs of compromised health at each location were sediment damage and algal overgrowth. These results support earlier findings that sedimentation and turbidity are major threats to in-shore reefs in New Caledonia. The Poritidae-dominated west coast locations were more subject to sediment damage, algal overgrowth and growth anomalies compared to the Acroporidae-dominated east coast locations. If growth form and resistance of coral hosts influence these results, differences in environmental conditions including hydro-dynamism between locations may also contribute to these outputs. Our results highlight the importance of combining coral health surveys with measurements of coral cover when assessing the health status of a reef, as reefs with high coral cover may have a high prevalence of corals demonstrating signs of compromised health.

  16. 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... regulations; or (3) fishing for, taking, or retaining any Potentially Harvested Coral Reef Taxa in the coral...

  17. 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...

  18. 76 FR 82413 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Science.gov (United States)

    2011-12-30

    ... Part 622 Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants... Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and... the FMP for the Spiny Lobster Fishery of Puerto Rico and the U.S. Virgin Islands (Spiny Lobster...

  19. 76 FR 59377 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Science.gov (United States)

    2011-09-26

    ..., Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates Fishery Management... Fishery Management Plans (FMPs) for Reef Fish Resources, Spiny Lobster, Queen Conch, and Coral and Reef... (AMs) if ACLs should be exceeded for selected reef fish, spiny lobster, and aquarium trade...

  20. The Use of Simulated Visible/Infrared Imager/Radiometer Suite (VIIRS) and Landsat Data Continuity Mission (LDCM) Imagery for Coral Reef Monitoring

    Science.gov (United States)

    Estep, L.; Spruce, J.; Blonski, S.; Moore, R.

    2008-01-01

    Coral reefs are some of the most biologically rich and economically important ecosystems on Earth. Coral reefs are Earth's largest biological structures and have taken thousands of years to form. Coral reefs not only provide important habitat for many marine animals and plants, but they also provide humanity with food, jobs, chemicals, protection against storms, and life-saving pharmaceuticals. Severe bleaching events have occurred that have dramatic long-term ecological impacts to corals, including loss of reef-building corals, changes in benthic habitat, and, in some cases, changes in larval fish populations (Holden and Ledrew, 1998). Some researchers suggest that 10 percent of Earth s coral reefs have already been destroyed and that another 60 percent are in danger. Scientists have proposed that as much as 95 percent of Jamaica's reefs are dying or dead. This poster reports on a Rapid Prototyping Capability (RPC) experiment done to determine whether future NASA sensors - the Visible/Infrared Imager/Radiometer Suite (VIIRS) and Landsat Data Continuity Mission (LDCM) - could generate key data products for the Integrated Coral Reef Observation Network (ICON)/Coral Reef Early Warning System (CREWS) Decision Support Tool (DST) operated by the National Oceanic and Atmospheric Administration (NOAA).

  1. Coral settlement on a highly disturbed equatorial reef system.

    Science.gov (United States)

    Bauman, Andrew G; Guest, James R; Dunshea, Glenn; Low, Jeffery; Todd, Peter A; Steinberg, Peter D

    2015-01-01

    Processes occurring early in the life stages of corals can greatly influence the demography of coral populations, and successful settlement of coral larvae that leads to recruitment is a critical life history stage for coral reef ecosystems. Although corals in Singapore persist in one the world's most anthropogenically impacted reef systems, our understanding of the role of coral settlement in the persistence of coral communities in Singapore remains limited. Spatial and temporal patterns of coral settlement were examined at 7 sites in the southern islands of Singapore, using settlement tiles deployed and collected every 3 months from 2011 to 2013. Settlement occurred year round, but varied significantly across time and space. Annual coral settlement was low (~54.72 spat m(-2) yr(-1)) relative to other equatorial regions, but there was evidence of temporal variation in settlement rates. Peak settlement occurred between March-May and September-November, coinciding with annual coral spawning periods (March-April and October), while the lowest settlement occurred from December-February during the northeast monsoon. A period of high settlement was also observed between June and August in the first year (2011/12), possibly due to some species spawning outside predicted spawning periods, larvae settling from other locations or extended larval settlement competency periods. Settlement rates varied significantly among sites, but spatial variation was relatively consistent between years, suggesting the strong effects of local coral assemblages or environmental conditions. Pocilloporidae were the most abundant coral spat (83.6%), while Poritidae comprised only 6% of the spat, and Acroporidae coral spat. These results indicate that current settlement patterns are reinforcing the local adult assemblage structure ('others'; i.e. sediment-tolerant coral taxa) in Singapore, but that the replenishment capacity of Singapore's reefs appears relatively constrained, which could lead

  2. Coral settlement on a highly disturbed equatorial reef system.

    Directory of Open Access Journals (Sweden)

    Andrew G Bauman

    Full Text Available Processes occurring early in the life stages of corals can greatly influence the demography of coral populations, and successful settlement of coral larvae that leads to recruitment is a critical life history stage for coral reef ecosystems. Although corals in Singapore persist in one the world's most anthropogenically impacted reef systems, our understanding of the role of coral settlement in the persistence of coral communities in Singapore remains limited. Spatial and temporal patterns of coral settlement were examined at 7 sites in the southern islands of Singapore, using settlement tiles deployed and collected every 3 months from 2011 to 2013. Settlement occurred year round, but varied significantly across time and space. Annual coral settlement was low (~54.72 spat m(-2 yr(-1 relative to other equatorial regions, but there was evidence of temporal variation in settlement rates. Peak settlement occurred between March-May and September-November, coinciding with annual coral spawning periods (March-April and October, while the lowest settlement occurred from December-February during the northeast monsoon. A period of high settlement was also observed between June and August in the first year (2011/12, possibly due to some species spawning outside predicted spawning periods, larvae settling from other locations or extended larval settlement competency periods. Settlement rates varied significantly among sites, but spatial variation was relatively consistent between years, suggesting the strong effects of local coral assemblages or environmental conditions. Pocilloporidae were the most abundant coral spat (83.6%, while Poritidae comprised only 6% of the spat, and Acroporidae <1%. Other, unidentifiable families represented 10% of the coral spat. These results indicate that current settlement patterns are reinforcing the local adult assemblage structure ('others'; i.e. sediment-tolerant coral taxa in Singapore, but that the replenishment capacity

  3. Acoustical Measurement and Biot Model for Coral Reef Detection and Quantification

    OpenAIRE

    Manik, Henry M.

    2016-01-01

    Coral reefs are coastal resources and very useful for marine ecosystems. Nowadays, the existence of coral reefs is seriously threatened due to the activities of blast fishing, coral mining, marine sedimentation, pollution, and global climate change. To determine the existence of coral reefs, it is necessary to study them comprehensively. One method to study a coral reef by using a propagation of sound waves is proposed. In this research, the measurement of reflection coefficient, transmission...

  4. 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.

  5. First frozen repository for the Great Barrier Reef coral created.

    Science.gov (United States)

    Hagedorn, Mary; van Oppen, Madeleine J H; Carter, Virginia; Henley, Mike; Abrego, David; Puill-Stephan, Eneour; Negri, Andrew; Heyward, Andrew; MacFarlane, Doug; Spindler, Rebecca

    2012-10-01

    To build new tools for the continued protection and propagation of coral from the Great Barrier Reef (GBR), an international group of coral and cryopreservation scientists known as the Reef Recovery Initiative joined forces during the November 2011 mass-spawning event. The outcome was the creation of the first frozen bank for Australian coral from two important GBR reef-building species, Acropora tenuis and Acropora millepora. Approximately 190 frozen samples each with billions of cells were placed into long-term storage. Sperm cells were successfully cryopreserved, and after thawing, samples were used to fertilize eggs, resulting in functioning larvae. Additionally, developing larvae were dissociated, and these pluripotent cells were cryopreserved and viable after thawing. Now, we are in a unique position to move our work from the laboratory to the reefs to develop collaborative, practical conservation management tools to help secure Australia's coral biodiversity.

  6. 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.

  7. Drivers of coral reef marine protected area performance

    National Research Council Canada - National Science Library

    Venetia Alexa Hargreaves-Allen; Susana Mourato; Eleanor Jane Milner-Gulland

    2017-01-01

    .... conservation or welfare related outcomes). We compiled a global dataset from expert knowledge for 76 coral reef MPAs in 33 countries and identified a set of performance measures reflecting ecological and socio-economic outcomes, achievement...

  8. 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...

  9. 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...

  10. Biomass and Abundance of Herbivorous Fishes on Coral Reefs off ...

    African Journals Online (AJOL)

    Keywords: Herbivorous fish, biomass, coral cover, algal turf, fishing, Marine. Protected ... effects of fishing intensity, reef geomorphology and benthic cover. Distance from the ... 2003), pollution ..... derived from distance from human community.

  11. 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.

  12. Reef ecology. Chemically mediated behavior of recruiting corals and fishes: a tipping point that may limit reef recovery.

    Science.gov (United States)

    Dixson, Danielle L; Abrego, David; Hay, Mark E

    2014-08-22

    Coral reefs are in global decline, converting from dominance by coral to dominance by seaweed. Once seaweeds become abundant, coral recovery is suppressed unless herbivores return to remove seaweeds, and corals then recruit. Variance in the recovery of fishes and corals is not well understood. We show that juveniles of both corals and fishes are repelled by chemical cues from fished, seaweed-dominated reefs but attracted to cues from coral-dominated areas where fishing is prohibited. Chemical cues of specific seaweeds from degraded reefs repulsed recruits, and cues from specific corals that are typical of healthy reefs attracted recruits. Juveniles were present at but behaviorally avoided recruiting to degraded reefs dominated by seaweeds. For recovery, degraded reefs may need to be managed to produce cues that attract, rather than repel, recruiting corals and fishes.

  13. 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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Andreas F. Haas

    2015-11-01

    Full Text Available 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 < 5 for N ≥ 3 and significantly correlated to microbial abundance at each site. This shows that mathematical approaches designed to assess the aesthetic appearance of photographic images can be used as an inexpensive monitoring tool for coral reef ecosystems. It further suggests that human perception of aesthetics is not purely subjective but influenced by inherent reactions towards measurable visual cues. By quantifying aesthetic features of coral reef 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.

  16. Effects of solar ultraviolet radiation on coral reef organisms.

    Science.gov (United States)

    Banaszak, Anastazia T; Lesser, Michael P

    2009-09-01

    Organisms living in shallow-water tropical coral reef environments are exposed to high UVR irradiances due to the low solar zenith angles (the angle of the sun from the vertical), the natural thinness of the ozone layer over tropical latitudes, and the high transparency of the water column. The hypothesis that solar ultraviolet radiation (UVR, 290-400 nm) is an important factor that affects the biology and ecology of coral reef organisms dates only to about 1980. It has been previously suggested that increased levels of biologically effective ultraviolet B radiation (UVB, 290-320 nm), which is the waveband primarily affected by ozone depletion, would have relatively small effects on corals and coral reefs and that these effects might be observed as changes in the minimum depths of occurrence of important reef taxa such as corals. This conclusion was based on predictions of increases in UVR as well as its attenuation with depth using the available data on UVR irradiances, ozone levels, and optical properties of the water overlying coral reefs. Here, we review the experimental evidence demonstrating the direct and indirect effects of UVR, both UVB and ultraviolet A (UVA, 320-400 nm) on corals and other reef associated biota, with emphasis on those studies conducted since 1996. Additionally, we re-examine the predictions made in 1996 for the increase in UVB on reefs with currently available data, assess whether those predictions were reasonable, and look at what changes might occur on coral reefs in the future as the multiple effects (i.e. increased temperature, hypercapnia, and ocean acidification) of global climate change continue.

  17. 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,...

  18. Ophiuroidea (Echinodermata) from coral reefs in the Mexican Pacific

    OpenAIRE

    Rebeca Granja Fernández; María Dinorah Herrero Pérezrul; Ramón Andrés López Pérez; Luis Hernández; Fabián Rodríguez Zaragoza; Robert Wallace Jones; Rubén Pineda López

    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...

  19. Forest conservation delivers highly variable coral reef conservation outcomes.

    Science.gov (United States)

    Klein, Carissa J; Jupiter, Stacy D; Selig, Elizabeth R; Watts, Matthew E; Halpern, Benjamin S; Kamal, Muhammad; Roelfsema, Chris; Possingham, Hugh P

    2012-06-01

    Coral reefs are threatened by human activities on both the land (e.g., deforestation) and the sea (e.g., overfishing). Most conservation planning for coral reefs focuses on removing threats in the sea, neglecting management actions on the land. A more integrated approach to coral reef conservation, inclusive of land-sea connections, requires an understanding of how and where terrestrial conservation actions influence reefs. We address this by developing a land-sea planning approach to inform fine-scale spatial management decisions and test it in Fiji. Our aim is to determine where the protection of forest can deliver the greatest return on investment for coral reef ecosystems. To assess the benefits of conservation to coral reefs, we estimate their relative condition as influenced by watershed-based pollution and fishing. We calculate the cost-effectiveness of protecting forest and find that investments deliver rapidly diminishing returns for improvements to relative reef condition. For example, protecting 2% of forest in one area is almost 500 times more beneficial than protecting 2% in another area, making prioritization essential. For the scenarios evaluated, relative coral reef condition could be improved by 8-58% if all remnant forest in Fiji were protected rather than deforested. Finally, we determine the priority of each coral reef for implementing a marine protected area when all remnant forest is protected for conservation. The general results will support decisions made by the Fiji Protected Area Committee as they establish a national protected area network that aims to protect 20% of the land and 30% of the inshore waters by 2020. Although challenges remain, we can inform conservation decisions around the globe by tackling the complex issues relevant to integrated land-sea planning.

  20. Resource partitioning along multiple niche axes drives functional diversity in parrotfishes on Caribbean coral reefs.

    Science.gov (United States)

    Adam, Thomas C; Kelley, Megan; Ruttenberg, Benjamin I; Burkepile, Deron E

    2015-12-01

    The recent loss of key consumers to exploitation and habitat degradation has significantly altered community dynamics and ecosystem function across many ecosystems worldwide. Predicting the impacts of consumer losses requires knowing the level of functional diversity that exists within a consumer assemblage. In this study, we document functional diversity among nine species of parrotfishes on Caribbean coral reefs. Parrotfishes are key herbivores that facilitate the maintenance and recovery of coral-dominated reefs by controlling algae and provisioning space for the recruitment of corals. We observed large functional differences among two genera of parrotfishes that were driven by differences in diet. Fishes in the genus Scarus targeted filamentous algal turf assemblages, crustose coralline algae, and endolithic algae and avoided macroalgae, while fishes in the genus Sparisoma preferentially targeted macroalgae. However, species with similar diets were dissimilar in other attributes, including the habitats they frequented, the types of substrate they fed from, and the spatial scale at which they foraged. These differences indicate that species that appear to be functionally redundant when looking at diet alone exhibit high levels of complementarity when we consider multiple functional traits. By identifying key functional differences among parrotfishes, we provide critical information needed to manage parrotfishes to enhance the resilience of coral-dominated reefs and reverse phase shifts on algal-dominated reefs throughout the wider Caribbean. Further, our study provides a framework for predicting the impacts of consumer losses in other species rich ecosystems.

  1. The effects of trophic interactions and spatial competition on algal community composition on Hawaiian coral reefs

    NARCIS (Netherlands)

    Vermeij, M.J.A.; Dailer, M.L.; Walsh, S.M.; Donovan, M.K.; Smith, C.M.

    2010-01-01

    Much of coral reef ecology has focused on how human impacts change coral reefs to macroalgal reefs. However, macroalgae may not always be a good indicator of reef decline, especially on reefs with significant sea urchin populations, as found in Kenya and Hawaii. This study tests the effects of troph

  2. The effects of trophic interactions and spatial competition on algal community composition on Hawaiian coral reefs

    NARCIS (Netherlands)

    Vermeij, M.J.A.; Dailer, M.L.; Walsh, S.M.; Donovan, M.K.; Smith, C.M.

    2010-01-01

    Much of coral reef ecology has focused on how human impacts change coral reefs to macroalgal reefs. However, macroalgae may not always be a good indicator of reef decline, especially on reefs with significant sea urchin populations, as found in Kenya and Hawaii. This study tests the effects of

  3. 76 FR 66273 - Snapper-Grouper Fishery Off the Southern Atlantic States and Coral and Coral Reefs Fishery in the...

    Science.gov (United States)

    2011-10-26

    ... Atlantic States and Coral and Coral Reefs Fishery in the South Atlantic; Exempted Fishing Permit AGENCY... conditions, various species of reef fish and live rock in Federal waters off North Carolina. The specimens... Plan (FMP) for the Snapper-Grouper Fishery of the South Atlantic Region and the FMP for Coral, Coral...

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

    Science.gov (United States)

    Roth, Melissa S; 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 acclimated and GFP concentration and fluorescence recovered. In contrast, heat-treated corals eventually bleached but showed strong fluorescence despite reduced GFP concentration, likely resulting from the large reduction in shading from decreased dinoflagellate density. Consequently, GFP concentration and fluorescence showed distinct correlations in non-bleached and bleached corals. Green fluorescence was positively correlated with dinoflagellate photobiology, but its closest correlation was with coral growth suggesting that green fluorescence could be used as a physiological proxy for health in some corals.

  5. 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.

    2014-01-01

    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 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

  6. Hurricanes and coral reefs: The intermediate disturbance hypothesis revisited

    Science.gov (United States)

    Rogers, C. S.

    1993-11-01

    A review of research on the effects of hurricanes on coral reefs suggests that the intermediate disturbance hypothesis may be applicable to shallow reef zones dominated by branching or foliaceous coral species that are especially susceptible to mechanical damage from storms. Diversity ( H') increases because of an increase in evenness following destruction or removal of the species that was monopolizing the space. The intermediate disturbance hypothesis as presented by Connell focuses on changes in number of species, but should be expanded to include diversity ( H') and evenness. It should also be modified to incorporate changes in living cover and the time elapsed since disturbances of varying intensities. This hypothesis predicts that when cover is high, diversity will be low. However, research on coral reefs does not consistently demonstrate an inverse correlation of coral diversity, and coral cover. An increase in cover and decrease in diversity with depth would also be expected because deeper reef zones generally experience less disturbance. However, higher diversity (both H' and species richness) is often associated with deeper zones. The effects of hurricanes on coral reefs will depend on the temporal and spatial scales under consideration, the life history characteristics and morphology of the dominant species, the depth of the reef zone, the ecological history of the site, and the influence of any additional natural or human stresses.

  7. Project Overview: A Reef Manager's Guide to Coral Bleaching ...

    Science.gov (United States)

    The purpose of this report is to provide the latest scientific knowledge and discuss available management options to assist local and regional managers in responding effectively to mass coral bleaching events. Background A Reef Manager’s Guide to Coral Bleaching is the result of a collaborative effort by over 50 scientists and managers to: (1) share the best available scientific information on climate-related coral bleaching; and (2) compile a tool kit of currently available strategies for adaptive management of coral reefs in a changing climate. The result is a compendium of current information, tools, and practical suggestions to aid managers in their efforts to protect reefs in a way that maximizes reef resilience in the face of continuing climate change. The Guide is a joint publication of the National Oceanic and Atmospheric Administration, the Great Barrier Reef Marine Park Authority, and The World Conservation Union, with author contributions from a variety of international partners from government agencies, non-governmental organizations, and academic institutions. EPA’s Office of Research and Development was a major contributor to the Guide through authorship and participation in the final review and editing process for the entire report. A Reef Manager’s Guide to Coral Bleaching is the result of a collaborative effort by over 50 scientists and managers to: (1) share the best available scientific information on climate-related coral blea

  8. Simplification of Caribbean reef-fish assemblages over decades of coral reef degradation

    National Research Council Canada - National Science Library

    Alvarez-Filip, Lorenzo; Paddack, Michelle J; Collen, Ben; Robertson, D Ross; Côté, Isabelle M

    2015-01-01

    ...., habitat generalists). Analysing 3727 abundance trends of 161 Caribbean reef-fishes, surveyed between 1980 and 2006, we found that the trends of habitat-generalists and habitat-specialists differed markedly...

  9. Simplification of Caribbean Reef-Fish Assemblages over Decades of Coral Reef Degradation: e0126004

    National Research Council Canada - National Science Library

    Lorenzo Alvarez-Filip; Michelle J Paddack; Ben Collen; D Ross Robertson; Isabelle M Côté

    2015-01-01

    ...., habitat generalists). Analysing 3727 abundance trends of 161 Caribbean reef-fishes, surveyed between 1980 and 2006, we found that the trends of habitat-generalists and habitat-specialists differed markedly...

  10. Oxygen consumption by a coral reef sponge.

    Science.gov (United States)

    Hadas, Eran; Ilan, Micha; Shpigel, Muki

    2008-07-01

    Oxygen consumption of the Red Sea coral reef sponge Negombata magnifica was measured using both incubation and steady-state methods. The latter method was found to be the more reliable because sponge activity remained stable over time. Oxygen consumption rate was measured during three levels of sponge activity: full activity, reduced activity and basal activity (starved). It was found that the active oxygen consumption rate of N. magnifica averaged 37.3+/-4.6 nmol O2 min(-1) g(-1) wet mass, which is within the upper range reported for other tropical marine sponges. Fully active N. magnifica individuals consumed an average of 41.8+/-3.2 nmol O2 min(-1) g(-1) wet mass. The mean basal respiration rate was 20.2+/-1.2 nmol O2 min(-1) g(-1) wet mass, which is 51.6+/-2.5% of the active respiration rate. Therefore, the oxygen used for water pumping was calculated to be at most 10.6+/-1.8 nmol O2 min(-1) g(-1) wet mass, which is 25.1+/-3.6% of the total respiration. Combined oxygen used for maintenance and water pumping activity was calculated to be 30.8 nmol O2 min(-1) g(-1) wet mass, which is approximately 74% of the sponge's total oxygen requirement. The remaining oxygen is directed to other physiological activities, mainly the energy requirement of growth. These findings suggest that only a relatively minor amount of energy is potentially available for growth, and thus might be a factor in controlling the growth rate of N. magnifica in oligotrophic coral reefs.

  11. Challenges for Ecosystem Services Provided by Coral Reefs In the Face of Climate Change

    Science.gov (United States)

    Kikuchi, R. K.; Elliff, C. I.

    2014-12-01

    to increase resilience and guarantee the adaptation of this ecosystem to climate change. Thus, considering that the majority of the marine ecosystem services we benefit from are provided from coastal habitats, of which coral reefs play an important role, the challenge at hand is in fact the interaction between local factors and climate change

  12. Embracing a world of subtlety and nuance on coral reefs

    Science.gov (United States)

    Mumby, Peter J.

    2017-09-01

    Climate change will homogenise the environment and generate a preponderance of mediocre reefs. Managing seascapes of mediocrity will be challenging because our science is ill prepared to deal with the `shades of grey' of reef health; we tend to study natural processes in the healthiest reefs available. Yet much can be gained by examining the drivers and implications of even subtle changes in reef state. Where strong ecological interactions are discovered, even small changes in abundance can have profound impacts on coral resilience. Indeed, if we are to develop effective early warnings of critical losses of resilience, then monitoring must place greater emphasis on measuring and interpreting changes in reef recovery rates. In terms of mechanism, a more nuanced approach is needed to explore the generality of what might be considered `dogma'. A more nuanced approach to science will serve managers needs well and help minimise the rise of mediocrity in coral reef ecosystems.

  13. Species diversity of Polychaete in coral reef ecosystem of Great Nicobar Island, India

    Directory of Open Access Journals (Sweden)

    V. SEKAR

    2016-01-01

    Full Text Available Abstract. Sekar V Rajasekaran R, Sachithanandam V, Sankar R, Sridhar R, Kingsley PW. 2016. Species diversity of Polychaete in coral reef ecosystem of Great Nicobar Island, India. Nusantara Bioscience 8: 71-76. Crypto fauna inhabiting the shelves of the coral reefs in Great Nicobar Islands are affected by bio-erosion caused by grazing and boring of organisms, hence present study revealed on two major components the opportunistic and true borers. Samples were collected from four stations from three different coral types (live coral, highly degraded & rubble of the Great Nicobar Islands. Of the total 401 individuals of Polychaetes collected from various sites 8 taxonomic species namely Terebella ehrenbergi, Idanthyrsus pennatus, Lysidice ninetta, L. collaris, Pseudonereis variegata, Perinereis cultrifera, P. nigropunctata, Eurythoe complanata were identified from the aforementioned three coral type sources. Among these P. variegata and L. collaris which accounted for 32.01% and 28.5% respectively, were the most dominant cryptic groups; whereas I. pennatus and T. ehrenbergi were the least records in all three habitats which accounted for 1.75%. In this study, the observations revealed that degraded corals were found in greater abundance than rubble and live corals. The species composition was observed maximum in Laxmi Nagar due to the availability of degraded coral patches than other stations. The study to evaluates the baseline knowledge of the coral inhabiting Polychaete distribution, it would be a pathway for forthcoming researchers on particular group taxonomy, and towards better understanding & utilization of coral reef ecosystem of the Great Nicobar Islands.

  14. Remote Sensing of Coral Reefs for Monitoring and Management: A Review

    Directory of Open Access Journals (Sweden)

    John D. Hedley

    2016-02-01

    Full Text Available Coral reefs are in decline worldwide and monitoring activities are important for assessing the impact of disturbance on reefs and tracking subsequent recovery or decline. Monitoring by field surveys provides accurate data but at highly localised scales and so is not cost-effective for reef scale monitoring at frequent time points. Remote sensing from satellites is an alternative and complementary approach. While remote sensing cannot provide the level of detail and accuracy at a single point than a field survey, the statistical power for inferring large scale patterns benefits in having complete areal coverage. This review considers the state of the art of coral reef remote sensing for the diverse range of objectives relevant for management, ranging from the composition of the reef: physical extent, benthic cover, bathymetry, rugosity; to environmental parameters: sea surface temperature, exposure, light, carbonate chemistry. In addition to updating previous reviews, here we also consider the capability to go beyond basic maps of habitats or environmental variables, to discuss concepts highly relevant to stakeholders, policy makers and public communication: such as biodiversity, environmental threat and ecosystem services. A clear conclusion of the review is that advances in both sensor technology and processing algorithms continue to drive forward remote sensing capability for coral reef mapping, particularly with respect to spatial resolution of maps, and synthesis across multiple data products. Both trends can be expected to continue.

  15. A role for partially protected areas on coral reefs: Maintaining fish diversity?

    KAUST Repository

    Tyler, Elizabeth

    2011-04-15

    1. Completely banning fishing from coral reefs is now accepted to have significant benefits for marine biodiversity and in many cases, fisheries. However, the benefits of regulating fishing on coral reefs, by restricting the methods used, or the total amount of fishing, are less well understood, even though such regulations are much more likely to be supported by fishermen. 2. This study assesses whether banning illegal, destructive fishing methods and reducing the numbers of fishermen visiting from outside an area benefits a coral reef fishery, despite unregulated fishing by local fishermen using non-destructive methods. 3. The abundance, biomass, mean length, and species richness of nine commercially important fish families are compared across ten independent patch reefs inside and outside the 470km2 Menai Bay Conservation Area in Zanzibar, Tanzania. 4. Even after taking into account the effect of differences in habitat and the distance between reefs, 61% (±19.7%) more fish species were found in regulated than unregulated reefs. Fish abundance, biomass, and length were not affected, suggesting that banning destructive fishing may improve biodiversity, but that further regulations may be required to improve fish stocks. © 2011 John Wiley and Sons, Ltd.

  16. 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...

  17. Morphogenesis of the branching reef coral Madracis mirabilis

    NARCIS (Netherlands)

    Kaandorp, J.A.; Sloot, P.M.A.; Merks, R.M.H.; Bak, R.P.M.; Vermeij, M.J.A.; Maier, C.

    2005-01-01

    Understanding external deciding factors in growth and morphology of reef corals is essential to elucidate the role of corals in marine ecosystems, and to explain their susceptibility to pollution and global climate change. Here, we extend on a previously presented model for simulating the growth and

  18. Trans-Atlantic rafting by the brooding reef coral

    NARCIS (Netherlands)

    Hoeksema, B.W.; Roos, P.J.; Cadée, G.C.

    2012-01-01

    including corrigendumSpecimens of the brooding reef coral Favia fragum were found on man-made flotsam stranded on the North Sea shore of the Netherlands. Based on the associated epifauna originating from the southeast USA, we estimate that the corals must have crossed the Atlantic Ocean, transported

  19. 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...

  20. Trans-Atlantic rafting by the brooding reef coral

    NARCIS (Netherlands)

    Hoeksema, B.W.; Roos, P.J.; Cadée, G.C.

    2012-01-01

    Specimens of the brooding reef coral Favia fragum were found on man-made flotsam stranded on the North Sea shore of the Netherlands. Based on the associated epifauna originating from the southeast USA, we estimate that the corals must have crossed the Atlantic Ocean, transported by the Gulf Stream a

  1. Human Impacts on Coral Reefs in the Sultanate of Oman

    Science.gov (United States)

    Al-Jufaili, S.; Al-Jabri, M.; Al-Baluchi, A.; Baldwin, R. M.; Wilson, S. C.; West, F.; Matthews, A. D.

    1999-08-01

    A rapid assessment survey of the coral reefs of the Sultanate of Oman was conducted by the Ministry of Regional Municipalities and Environment during the first half of 1996. The survey revealed new information on the distribution pattern of corals in Oman and identified impacts, threats and potential threats to coral communities for the purpose of preparation of a National Coral Reef Management Plan (Phase One of the implementation of a National Coastal Zone Management Plan). Impacts on coral reefs in Oman were found to be attributable to both natural and human causes, resulting in significant and widespread degradation. Damage resulting from fisheries activities was the most commonly recorded human impact, with the most severe effects. Other human impacts resulted from coastal construction, recreational activities, oil pollution and eutrophication. Predation of corals by Acanthaster planci, damage caused by storms, coral diseases and temperature-related stress were the most commonly recorded natural impacts to coral reefs. Further minor natural impacts were attributable to siltation, rock falls and predation by a corallivorous gastropod (Drupella sp.). Significant differences between different areas of the country were found in terms of human impacts on coral reefs and these were related to coastal demography and human activity. Eighty per cent of sites studied were recorded to have been affected by human impacts to some degree. Impacts attributable to fisheries activities were found at 69% of the sites. Lost or abandoned gill nets were found to affect coral reefs at 49% of sites throughout Oman and accounted for 70% of all severe human impacts. Lost gill nets were also found to have a negative affect on fisheries resources and other marine wildlife. Observations of the behaviour of gill nets on coral reefs suggested a predictable pattern of damage over time and a significant increase in damage intensity during storms. Fishing nets were found to act selectively

  2. Norwegian deep-water coral reefs: cultivation and molecular analysis of planktonic microbial communities.

    Science.gov (United States)

    Jensen, Sigmund; Lynch, Michael D J; Ray, Jessica L; Neufeld, Josh D; Hovland, Martin

    2015-10-01

    Deep-sea coral reefs do not receive sunlight and depend on plankton. Little is known about the plankton composition at such reefs, even though they constitute habitats for many invertebrates and fish. We investigated plankton communities from three reefs at 260-350 m depth at hydrocarbon fields off the mid-Norwegian coast using a combination of cultivation and small subunit (SSU) rRNA gene and transcript sequencing. Eight months incubations of a reef water sample with minimal medium, supplemented with carbon dioxide and gaseous alkanes at in situ-like conditions, enabled isolation of mostly Alphaproteobacteria (Sulfitobacter, Loktanella), Gammaproteobacteria (Colwellia) and Flavobacteria (Polaribacter). The relative abundance of isolates in the original sample ranged from ∼ 0.01% to 0.80%. Comparisons of bacterial SSU sequences from filtered plankton of reef and non-reef control samples indicated high abundance and metabolic activity of primarily Alphaproteobacteria (SAR11 Ia), Gammaproteobacteria (ARCTIC96BD-19), but also of Deltaproteobacteria (Nitrospina, SAR324). Eukaryote SSU sequences indicated metabolically active microalgae and animals, including codfish, at the reef sites. The plankton community composition varied between reefs and differed between DNA and RNA assessments. Over 5000 operational taxonomic units were detected, some indicators of reef sites (e.g. Flavobacteria, Cercozoa, Demospongiae) and some more active at reef sites (e.g. Gammaproteobacteria, Ciliophora, Copepoda). © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Benthic habitat map of the U.S. Coral Reef Task Force Watershed Partnership Initiative Kā'anapali priority study area and the State of Hawai'i Kahekili Herbivore Fisheries Management Area, west-central Maui, Hawai'i

    Science.gov (United States)

    Cochran, Susan A.; Gibbs, Ann E.; White, Darla J.

    2014-01-01

    Nearshore areas off of west-central Maui, Hawai‘i, once dominated by abundant coral coverage, now are characterized by an increased abundance of turf algae and macroalgae. In an effort to improve the health and resilience of the coral reef system, the Kahekili Herbivore Fisheries Management Area was established by the State of Hawai‘i, and the U.S. Coral Reef Task Force selected the Kā‘anapali region as a priority study area. To support these efforts, the U.S. Geological survey mapped nearly 5 km2 of sea floor from the shoreline to water depths of about 30 m. Unconsolidated sediment (predominantly sand) constitutes 65 percent of the sea floor in the mapped area. Reef and other hardbottom potentially available for coral recruitments constitutes 35 percent of the mapped area. Of this potentially available hardbottom, only 51 percent is covered with a minimum of 10 percent coral, and most is found between 5 and 10 m water depth.

  4. Cold-Water Coral Habitats in Submarine Canyons of the Bay of Biscay

    Directory of Open Access Journals (Sweden)

    Inge M. J. van den Beld

    2017-05-01

    Full Text Available The topographical and hydrological complexity of submarine canyons, coupled with high substratum heterogeneity, make them ideal environments for cold-water coral (CWC habitats. These habitats, including reefs, are thought to provide important functions for many organisms. The canyons incising the continental slope of the Bay of Biscay have distinct morphological differences from the north to the south. CWCs have been reported from this basin in the late nineteenth century; however, little is known about their present-day distribution, diversity and environmental drivers in the canyons. In this study, the characteristics and distribution of CWC habitats in the submarine canyons of the Bay of Biscay are investigated. Twenty-four canyons and three locations between adjacent canyons were sampled using a Remotely Operated Vehicle (ROV or a towed camera system. Acquired images were annotated for habitat type (using the CoralFISH classification system, substrate cover and coral identification. Furthermore, the influence of hydrological factors and geomorphology on the CWC distribution was investigated. Eleven coral habitats, formed by 62 morphotypes of scleractinians, gorgonians, antipatharians and seapens, inhabiting hard and/or soft substrate, were observed. The distribution patterns were heterogenous at regional and local scales; the south Bay of Biscay and the southeastern flank favored soft substrate habitats. Biogenic and hard substrate habitats supported higher coral diversities than soft substrate habitats and had similar species compositions. A higher coral species turnover characterized soft substrate habitats. Substrate type was the most important driver of the patterns in both distribution and composition. Observations of coral reefs on steeper areas in the canyons and coral rubble on flatter areas on the interfluve/upper slope support the hypothesis that canyons serve as refuges, being less accessible to trawling, although natural causes

  5. Umbrella species in marine systems: using the endangered humphead wrasse to conserve coral reefs

    DEFF Research Database (Denmark)

    Weng, Kevin C.; Pedersen, Martin Wæver; Del Raye, Gen A.

    2015-01-01

    Extinction risk is closely tied to body size, home range, and species distribution. Quantifying home range is critical for conservation, and can enable the use of concepts such as ‘umbrella species’, whose conservation protects other species due to shared habitat. To determine the value...... of the humphead wrasse as an umbrella species for coral reef conservation, we conducted a multi-year study of humphead wrasse home range at Palmyra Atoll, Central Tropical Pacific, tagging juvenile, female, and male individuals with acoustic transmitters. We quantified home range using 2 metrics, length and area.......4 to 14 km and changed with ontogeny. Females had larger home ranges than other reef fishes studied to date (n = 68), indicating value as an umbrella species for coral reefs. We compared the home range of the species to the size distribution of tropical marine protected areas (MPAs), and used a model...

  6. Water Quality Standards for Coral Reef Protection | Science ...

    Science.gov (United States)

    The U.S. Clean Water Act provides a legal framework to protect coastal biological resources such as coral reefs, mangrove forests, and seagrass meadows from the damaging effects of human activities. Even though many resources are protected under this authority, water quality standards have not been effectively applied to coral reefs. The Environmental Protection Agency is promoting biocriteria and other water quality standards through collaborative development of bioassessment procedures, indicators and monitoring strategies. To support regulatory action, bioassessment indicators must be biologically meaningful, relevant to management, responsive to human disturbance, and relatively immune to natural variability. A rapid bioassessment protocol for reef-building stony corals was developed and tested for regulatory applicability. Preliminary testing in the Florida Keys found indicators had sufficient precision and provided information relevant to coral reef management. Sensitivity to human disturbance was demonstrated in the U.S. Virgin Islands for five of eight indicators tested. Once established, monitoring programs using these indicators can provide valuable, long-term records of coral condition and regulatory compliance. Development of a rapid bioassement protocol for reef-building stony corals was tested for regulatory applicability.

  7. Potential Habitat of Acropora spp. on Reefs of Florida, Puerto Rico, and the US Virgin Islands

    Directory of Open Access Journals (Sweden)

    Katherine E. Wirt

    2015-01-01

    Full Text Available Elkhorn and staghorn corals (Acropora palmata, Acropora cervicornis were listed in 2006 as threatened under the Endangered Species Act. The goal of this study was to create model potential-habitat maps for A. palmata and A. cervicornis, while identifying areas for possible re-establishment. These maps were created using a database of reported field observations in combination with existing benthic habitat maps. The mapped coral reef and hardbottom classifications throughout Florida, Puerto Rico, and the US Virgin Island reef tracts were used to generate potential-habitat polygons using buffers that incorporated 95% and 99% of reported observations of Acropora spp. Locations of 92% of A. palmata observations and 84% of A. cervicornis observations coincided with mapped coral reef or hard-bottom habitat throughout the study area. These results indicate that potential habitat for A. palmata is currently well defined throughout this region, but that potential habitat for A. cervicornis is more variable and has a wider range than that for A. palmata. This study provides a novel method of combining data sets at various geographic spatial scales and may be used to inform and refine the current National Oceanic and Atmospheric Administration critical habitat map.

  8. Quaternary onset and evolution of Kimberley coral reefs (Northwest Australia) revealed by high-resolution seismic imaging

    Science.gov (United States)

    Bufarale, Giada; Collins, Lindsay B.; O'Leary, Michael J.; Stevens, Alexandra; Kordi, Moataz; Solihuddin, Tubagus

    2016-07-01

    conditions, high-turbidity and frequent high-energy cyclonic events, corals have exhibited prolific reef growth during the Holocene developing significant reef accretionary structures. As a result coral reefs have generating habitat complexity and species diversity in what is a biodiversity hotspot.

  9. 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...

  10. 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...

  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. Sewage impacts coral reefs at multiple levels of ecological organization.

    Science.gov (United States)

    Reopanichkul, Pasinee; Schlacher, Thomas A; Carter, R W; Worachananant, Suchai

    2009-09-01

    Against a backdrop of rising sea temperatures and ocean acidification which pose global threats to coral reefs, excess nutrients and turbidity continue to be significant stressors at regional and local scales. Because interventions usually require local data on pollution impacts, we measured ecological responses to sewage discharges in Surin Marine Park, Thailand. Wastewater disposal significantly increased inorganic nutrients and turbidity levels, and this degradation in water quality resulted in substantial ecological shifts in the form of (i) increased macroalgal density and species richness, (ii) lower cover of hard corals, and (iii) significant declines in fish abundance. Thus, the effects of nutrient pollution and turbidity can cascade across several levels of ecological organization to change key properties of the benthos and fish on coral reefs. Maintenance or restoration of ecological reef health requires improved wastewater management and run-off control for reefs to deliver their valuable ecosystems services.

  13. Projecting coral reef futures under global warming and ocean acidification.

    Science.gov (United States)

    Pandolfi, John M; Connolly, Sean R; Marshall, Dustin J; Cohen, Anne L

    2011-07-22

    Many physiological responses in present-day coral reefs to climate change are interpreted as consistent with the imminent disappearance of modern reefs globally because of annual mass bleaching events, carbonate dissolution, and insufficient time for substantial evolutionary responses. Emerging evidence for variability in the coral calcification response to acidification, geographical variation in bleaching susceptibility and recovery, responses to past climate change, and potential rates of adaptation to rapid warming supports an alternative scenario in which reef degradation occurs with greater temporal and spatial heterogeneity than current projections suggest. Reducing uncertainty in projecting coral reef futures requires improved understanding of past responses to rapid climate change; physiological responses to interacting factors, such as temperature, acidification, and nutrients; and the costs and constraints imposed by acclimation and adaptation.

  14. A unified model explains commonness and rarity on coral reefs.

    Science.gov (United States)

    Connolly, Sean R; Hughes, Terry P; Bellwood, David R

    2017-04-01

    Abundance patterns in ecological communities have important implications for biodiversity maintenance and ecosystem functioning. However, ecological theory has been largely unsuccessful at capturing multiple macroecological abundance patterns simultaneously. Here, we propose a parsimonious model that unifies widespread ecological relationships involving local aggregation, species-abundance distributions, and species associations, and we test this model against the metacommunity structure of reef-building corals and coral reef fishes across the western and central Pacific. For both corals and fishes, the unified model simultaneously captures extremely well local species-abundance distributions, interspecific variation in the strength of spatial aggregation, patterns of community similarity, species accumulation, and regional species richness, performing far better than alternative models also examined here and in previous work on coral reefs. Our approach contributes to the development of synthetic theory for large-scale patterns of community structure in nature, and to addressing ongoing challenges in biodiversity conservation at macroecological scales.

  15. Status of Caribbean coral reefs in seven countries in 1986.

    Science.gov (United States)

    Wilkinson, Clive; Nowak, Madeleine; Miller, Ian; Baker, Valonna

    2013-05-15

    There are few long-term datasets available to make reliable statements about trends in cover and structure in many coral reefs around the world. We present 27year old summary data of the cover of corals and other biota on Caribbean and Western Atlantic coral reefs in 7 countries collected in late 1985 and early 1986. These data were collected to support research on sponge populations and show relatively low coral cover on many of these reefs with particularly low cover of Acropora spp. We present these summaries to encourage other researchers to compare with current conditions or repeat the surveys to show long-term trends; the raw data will be supplied on request. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Avoiding coral reef functional collapse requires local and global action.

    Science.gov (United States)

    Kennedy, Emma V; Perry, Chris T; Halloran, Paul R; Iglesias-Prieto, Roberto; Schönberg, Christine H L; Wisshak, Max; Form, Armin U; Carricart-Ganivet, Juan P; Fine, Maoz; Eakin, C Mark; Mumby, Peter J

    2013-05-20

    Coral reefs face multiple anthropogenic threats, from pollution and overfishing to the dual effects of greenhouse gas emissions: rising sea temperature and ocean acidification. While the abundance of coral has declined in recent decades, the implications for humanity are difficult to quantify because they depend on ecosystem function rather than the corals themselves. Most reef functions and ecosystem services are founded on the ability of reefs to maintain their three-dimensional structure through net carbonate accumulation. Coral growth only constitutes part of a reef's carbonate budget; bioerosion processes are influential in determining the balance between net structural growth and disintegration. Here, we combine ecological models with carbonate budgets and drive the dynamics of Caribbean reefs with the latest generation of climate models. Budget reconstructions using documented ecological perturbations drive shallow (6-10 m) Caribbean forereefs toward an increasingly fragile carbonate balance. We then projected carbonate budgets toward 2080 and contrasted the benefits of local conservation and global action on climate change. Local management of fisheries (specifically, no-take marine reserves) and the watershed can delay reef loss by at least a decade under "business-as-usual" rises in greenhouse gas emissions. However, local action must be combined with a low-carbon economy to prevent degradation of reef structures and associated ecosystem services. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Atoll-scale patterns in coral reef community structure: Human signatures on Ulithi Atoll, Micronesia.

    Science.gov (United States)

    Crane, Nicole L; Nelson, Peter; Abelson, Avigdor; Precoda, Kristin; Rulmal, John; Bernardi, Giacomo; Paddack, Michelle

    2017-01-01

    The dynamic relationship between reefs and the people who utilize them at a subsistence level is poorly understood. This paper characterizes atoll-scale patterns in shallow coral reef habitat and fish community structure, and correlates these with environmental characteristics and anthropogenic factors, critical to conservation efforts for the reefs and the people who depend on them. Hierarchical clustering analyses by site for benthic composition and fish community resulted in the same 3 major clusters: cluster 1-oceanic (close proximity to deep water) and uninhabited (low human impact); cluster 2-oceanic and inhabited (high human impact); and cluster 3-lagoonal (facing the inside of the lagoon) and inhabited (highest human impact). Distance from village, reef exposure to deep water and human population size had the greatest effect in predicting the fish and benthic community structure. Our study demonstrates a strong association between benthic and fish community structure and human use across the Ulithi Atoll (Yap State, Federated States of Micronesia) and confirms a pattern observed by local people that an 'opportunistic' scleractinian coral (Montipora sp.) is associated with more highly impacted reefs. Our findings suggest that small human populations (subsistence fishing) can nevertheless have considerable ecological impacts on reefs due, in part, to changes in fishing practices rather than overfishing per se, as well as larger global trends. Findings from this work can assist in building local capacity to manage reef resources across an atoll-wide scale, and illustrates the importance of anthropogenic impact even in small communities.

  18. 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...

  19. Spatial competition dynamics between reef corals under ocean acidification

    Science.gov (United States)

    Horwitz, Rael; Hoogenboom, Mia O.; Fine, Maoz

    2017-01-01

    Climate change, including ocean acidification (OA), represents a major threat to coral-reef ecosystems. Although previous experiments have shown that OA can negatively affect the fitness of reef corals, these have not included the long-term effects of competition for space on coral growth rates. Our multispecies year-long study subjected reef-building corals from the Gulf of Aqaba (Red Sea) to competitive interactions under present-day ocean pH (pH 8.1) and predicted end-of-century ocean pH (pH 7.6). Results showed coral growth is significantly impeded by OA under intraspecific competition for five out of six study species. Reduced growth from OA, however, is negligible when growth is already suppressed in the presence of interspecific competition. Using a spatial competition model, our analysis indicates shifts in the competitive hierarchy and a decrease in overall coral cover under lowered pH. Collectively, our case study demonstrates how modified competitive performance under increasing OA will in all likelihood change the composition, structure and functionality of reef coral communities. PMID:28067281

  20. Spatial competition dynamics between reef corals under ocean acidification

    Science.gov (United States)

    Horwitz, Rael; Hoogenboom, Mia O.; Fine, Maoz

    2017-01-01

    Climate change, including ocean acidification (OA), represents a major threat to coral-reef ecosystems. Although previous experiments have shown that OA can negatively affect the fitness of reef corals, these have not included the long-term effects of competition for space on coral growth rates. Our multispecies year-long study subjected reef-building corals from the Gulf of Aqaba (Red Sea) to competitive interactions under present-day ocean pH (pH 8.1) and predicted end-of-century ocean pH (pH 7.6). Results showed coral growth is significantly impeded by OA under intraspecific competition for five out of six study species. Reduced growth from OA, however, is negligible when growth is already suppressed in the presence of interspecific competition. Using a spatial competition model, our analysis indicates shifts in the competitive hierarchy and a decrease in overall coral cover under lowered pH. Collectively, our case study demonstrates how modified competitive performance under increasing OA will in all likelihood change the composition, structure and functionality of reef coral communities.

  1. Reef Habitat Type and Spatial Extent as Interacting Controls on Platform-Scale Carbonate Budgets

    Directory of Open Access Journals (Sweden)

    Chris T. Perry

    2017-06-01

    Full Text Available A coral reefs carbonate budget strongly influences reef structural complexity and net reef growth potential, and thus is increasingly recognized as a key “health” metric. Despite this, understanding of habitat specific budget states, how these scale across reef platforms, and our ability to quantify both framework and sediment production values remains limited. Here, we use in-situ census data from an atoll rim reef platform in the central Maldives to quantify rates of both reef framework and sediment production and loss within different platform habitats, and then combine these data with high-resolution habitat maps to quantify contributions to platform wide carbonate budgets. The net reef framework budget for the entire platform is extremely low (0.12 G, where G = Kg CaCO3 m−2 year−1, with a very high proportion (143,745 kg or 65.1% of total framework production generated within the platform margin reef zones, despite these comprising only ~8% of platform area. Net platform-scale sediment budgets are higher (1.04 G, but most is produced in the reef and platform margin hardground habitats, of which ~80% derives from parrotfish bioerosion. Significant quantities of new sediment (up to ~1 G derived from the calcareous green algae Halimeda are produced only in one habitat. All lagoonal habitats have negative or neutral net carbonate budgets. These data demonstrate the marked inter-habitat differences in reef carbonate budgets that occur across reef platforms, and the major dampening effect on overall platform scale budgets when rates are factored for habitat type and size. Furthermore, the data highlights the disproportionately important role that relatively small areas of reef habitat can have on the maintenance of net positive platform scale budgets. Because of the intrinsic link between carbonate production rates and reef-associated landform development and maintenance, these findings also have implications for understanding reef

  2. 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.

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

    Science.gov (United States)

    Klein, Carissa J; Ban, Natalie C; Halpern, Benjamin S; Beger, Maria; Game, Edward T; Grantham, Hedley S; Green, Alison; Klein, Travis J; Kininmonth, Stuart; Treml, Eric; Wilson, Kerrie; Possingham, Hugh P

    2010-08-30

    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. 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. 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.

  4. Shifts in coral-assemblage composition do not ensure persistence of reef functionality.

    Science.gov (United States)

    Alvarez-Filip, Lorenzo; Carricart-Ganivet, Juan P; Horta-Puga, Guillermo; Iglesias-Prieto, Roberto

    2013-12-12

    Coral communities are changing rapidly worldwide through loss of coral cover and shifts in species composition. Although many reef-building corals are likely to decline, some weedy opportunistic species might increase in abundance. Here we explore whether the reshuffling of species can maintain ecosystem integrity and functioning. Using four common Caribbean reef-building coral genera we modeled rates of reef construction and complexity. We show that shifting coral assemblages result in rapid losses in coral-community calcification and reef rugosity that are independent of changes in the total abundance of reef corals. These losses are considerably higher than those recently attributed to climate change. Dominance patterns of coral assemblages seem to be the most important driver of the functioning of coral reefs and thus, the future of these ecosystems might depend not only on reductions of local and global stressors, but also on the maintenance of keystone coral species.

  5. 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...

  6. Seascape context and predators override water quality effects on inshore coral reef fish communities

    Science.gov (United States)

    Gilby, Ben L.; Tibbetts, Ian R.; Olds, Andrew D.; Maxwell, Paul S.; Stevens, Tim

    2016-09-01

    Understanding the relative influence of factors that influence faunal community structure, such as habitat and landscape arrangement, has been a long-standing goal of ecologists. This is complicated in marine environments by the high importance of physico-chemical water factors in determining species distributions relative to their physiological or behavioural limits. In this study, we rank the relative importance of 17 seascape, habitat and physico-chemical water factors for structuring the composition of fish communities on the inshore coral reefs of Moreton Bay, eastern Australia. Fish were surveyed at 12 reef sites along the ambient estuarine water gradient in the bay during summer and winter using a baited underwater video approach. Multivariate random forest analyses showed that reef fish community composition correlated most strongly with the local abundance of piscivorous fish and the seascape context of individual reefs (especially distance to nearest seagrass and mangroves), while water quality factors ranked much lower in importance. However, fish communities from sites nearer to rivers were more spatiotemporally variable than those from sites nearer to oceanic waters, indicating that water quality can drive variations in community structure along short-term temporal scales. In turn, piscivore abundance was greatest on reefs near large areas of seagrass, and with low sand cover, high coral cover and high water clarity. Our findings demonstrate that a reef's location within the broader seascape can be more important for fish communities than factors relating to the reef habitat itself and exposure to reduced water quality. To improve the spatial conservation of marine ecosystems, we encourage a more intimate understanding of how these factors contribute to structuring the use of habitats across seascapes by mobile species.

  7. Habitat selection, facilitation, and biotic settlement cues affect distribution and performance of coral recruits in French Polynesia.

    Science.gov (United States)

    Price, Nichole

    2010-07-01

    Habitat selection can determine the distribution and performance of individuals if the precision with which sites are chosen corresponds with exposure to risks or resources. Contrastingly, facilitation can allow persistence of individuals arriving by chance and potentially maladapted to local abiotic conditions. For marine organisms, selection of a permanent attachment site at the end of their larval stage or the presence of a facilitator can be a critical determinant of recruitment success. In coral reef ecosystems, it is well known that settling planula larvae of reef-building corals use coarse environmental cues (i.e., light) for habitat selection. Although laboratory studies suggest that larvae can also use precise biotic cues produced by crustose coralline algae (CCA) to select attachment sites, the ecological consequences of biotic cues for corals are poorly understood in situ. In a field experiment exploring the relative importance of biotic cues and variability in habitat quality to recruitment of hard corals, pocilloporid and acroporid corals recruited more frequently to one species of CCA, Titanoderma prototypum, and significantly less so to other species of CCA; these results are consistent with laboratory assays from other studies. The provision of the biotic cue accurately predicted coral recruitment rates across habitats of varying quality. At the scale of CCA, corals attached to the "preferred" CCA experienced increased survivorship while recruits attached elsewhere had lower colony growth and survivorship. For reef-building corals, the behavioral selection of habitat using chemical cues both reduces the risk of incidental mortality and indicates the presence of a facilitator.

  8. 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.

  9. Functional connectivity of coral reef fishes in a tropical seascape assessed by compound-specific stable isotope analyses

    KAUST Repository

    McMahon, Kelton W.

    2011-01-01

    The ecological integrity of tropical habitats, including mangroves, seagrass beds and coral reefs, is coming under increasing pressure from human activities. Many coral reef fish species are thought to use mangroves and seagrass beds as juvenile nurseries before migrating to coral reefs as adults. Identifying essential habitats and preserving functional linkages among these habitats is likely necessary to promote ecosystem health and sustainable fisheries on coral reefs. This necessitates quantitative assessment of functional connectivity among essential habitats at the seascape level. This thesis presents the development and first application of a method for tracking fish migration using amino acid (AA) δ13C analysis in otoliths. In a controlled feeding experiment with fish reared on isotopically distinct diets, we showed that essential AAs exhibited minimal trophic fractionation between consumer and diet, providing a δ13C record of the baseline isoscape. We explored the potential for geochemical signatures in otoliths of snapper to act as natural tags of residency in seagrass beds, mangroves and coral reefs in the Red Sea, Caribbean Sea and Eastern Pacific Ocean. The δ13C values of otolith essential AAs varied as a function of habitat type and provided a better tracer of residence in juvenile nursery habitats than conventional bulk stable isotope analyses (SIA). Using our otolith AA SIA approach, we quantified the relative contribution of coastal wetlands and reef habitats to Lutjanus ehrenbergii populations on coastal, shelf and oceanic coral reefs in the Red Sea. L. ehrenbergii made significant ontogenetic migrations, traveling more than 30 km from juvenile nurseries to coral reefs and across deep open water. Coastal wetlands were important nurseries for L. ehrenbergii; however, there was significant plasticity in L. ehrenbergii juvenile habitat requirements. Seascape configuration played an important role in determining the functional connectivity of L

  10. Ecological effects of ocean acidification and habitat complexity on reef-associated macroinvertebrate communities.

    Science.gov (United States)

    Fabricius, K E; De'ath, G; Noonan, S; Uthicke, S

    2014-01-22

    The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO2) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classes and phyla) of macroinvertebrates were significantly reduced at elevated CO2 (425-1100 µatm) compared with control sites. However, sensitivities of some groups, including decapod crustaceans, ascidians and several echinoderms, contrasted with predictions of their physiological CO2 tolerances derived from laboratory experiments. High CO2 reduced the availability of structurally complex corals that are essential refugia for many reef-associated macroinvertebrates. This loss of habitat complexity was also associated with losses in many macroinvertebrate groups, especially predation-prone mobile taxa, including crustaceans and crinoids. The transition from living to dead coral as substratum and habitat further altered macroinvertebrate communities, with far more taxa losing than gaining in numbers. Our study shows that indirect ecological effects of OA (reduced habitat complexity) will complement its direct physiological effects and together with the loss of coral cover through climate change will severely affect macroinvertebrate communities in coral reefs.

  11. Risk assessment and predator learning in a changing world: understanding the impacts of coral reef degradation

    Science.gov (United States)

    Chivers, Douglas P.; McCormick, Mark I.; Allan, Bridie J. M.; Ferrari, Maud C. O.

    2016-09-01

    Habitat degradation is among the top drivers of the loss of global biodiversity. This problem is particularly acute in coral reef system. Here we investigated whether coral degradation influences predator risk assessment and learning for damselfish. When in a live coral environment, Ambon damselfish were able to learn the identity of an unknown predator upon exposure to damselfish alarm cues combined with predator odour and were able to socially transmit this learned recognition to naïve conspecifics. However, in the presence of dead coral water, damselfish failed to learn to recognize the predator through alarm cue conditioning and hence could not transmit the information socially. Unlike alarm cues of Ambon damselfish that appear to be rendered unusable in degraded coral habitats, alarm cues of Nagasaki damselfish remain viable in this same environment. Nagasaki damselfish were able to learn predators through conditioning with alarm cues in degraded habitats and subsequently transmit the information socially to Ambon damselfish. Predator-prey dynamics may be profoundly affected as habitat degradation proceeds; the success of one species that appears to have compromised predation assessment and learning, may find itself reliant on other species that are seemingly unaffected by the same degree of habitat degradation.

  12. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. 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.

    2016-02-01

    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.

  14. 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

    2016-02-15

    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.

  15. Management Strategy Evaluation Applied to Coral Reef Ecosystems in Support of Ecosystem-Based Management.

    Science.gov (United States)

    Weijerman, Mariska; Fulton, Elizabeth A; Brainard, Russell E

    2016-01-01

    Ecosystem modelling is increasingly used to explore ecosystem-level effects of changing environmental conditions and management actions. For coral reefs there has been increasing interest in recent decades in the use of ecosystem models for evaluating the effects of fishing and the efficacy of marine protected areas. However, ecosystem models that integrate physical forcings, biogeochemical and ecological dynamics, and human induced perturbations are still underdeveloped. We applied an ecosystem model (Atlantis) to the coral reef ecosystem of Guam using a suite of management scenarios prioritized in consultation with local resource managers to review the effects of each scenario on performance measures related to the ecosystem, the reef-fish fishery (e.g., fish landings) and coral habitat. Comparing tradeoffs across the selected scenarios showed that each scenario performed best for at least one of the selected performance indicators. The integrated 'full regulation' scenario outperformed other scenarios with four out of the six performance metrics at the cost of reef-fish landings. This model application quantifies the socio-ecological costs and benefits of alternative management scenarios. When the effects of climate change were taken into account, several scenarios performed equally well, but none prevented a collapse in coral biomass over the next few decades assuming a business-as-usual greenhouse gas emissions scenario.

  16. Management Strategy Evaluation Applied to Coral Reef Ecosystems in Support of Ecosystem-Based Management.

    Directory of Open Access Journals (Sweden)

    Mariska Weijerman

    Full Text Available Ecosystem modelling is increasingly used to explore ecosystem-level effects of changing environmental conditions and management actions. For coral reefs there has been increasing interest in recent decades in the use of ecosystem models for evaluating the effects of fishing and the efficacy of marine protected areas. However, ecosystem models that integrate physical forcings, biogeochemical and ecological dynamics, and human induced perturbations are still underdeveloped. We applied an ecosystem model (Atlantis to the coral reef ecosystem of Guam using a suite of management scenarios prioritized in consultation with local resource managers to review the effects of each scenario on performance measures related to the ecosystem, the reef-fish fishery (e.g., fish landings and coral habitat. Comparing tradeoffs across the selected scenarios showed that each scenario performed best for at least one of the selected performance indicators. The integrated 'full regulation' scenario outperformed other scenarios with four out of the six performance metrics at the cost of reef-fish landings. This model application quantifies the socio-ecological costs and benefits of alternative management scenarios. When the effects of climate change were taken into account, several scenarios performed equally well, but none prevented a collapse in coral biomass over the next few decades assuming a business-as-usual greenhouse gas emissions scenario.

  17. 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...

  18. 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...

  19. 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 agencies...

  20. 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 f