WorldWideScience

Sample records for barrier reef sponge

  1. A decadal analysis of bioeroding sponge cover on the inshore Great Barrier Reef.

    Science.gov (United States)

    Ramsby, Blake D; Hoogenboom, Mia O; Whalan, Steve; Webster, Nicole S; Thompson, Angus

    2017-06-02

    Decreasing coral cover on the Great Barrier Reef (GBR) may provide opportunities for rapid growth and expansion of other taxa. The bioeroding sponges Cliona spp. are strong competitors for space and may take advantage of coral bleaching, damage, and mortality. Benthic surveys of the inshore GBR (2005-2014) revealed that the percent cover of the most abundant bioeroding sponge species, Cliona orientalis, has not increased. However, considerable variation in C. orientalis cover, and change in cover over time, was evident between survey locations. We assessed whether biotic or environmental characteristics were associated with variation in C. orientalis distribution and abundance. The proportion of fine particles in the sediments was negatively associated with the presence-absence and the percent cover of C. orientalis, indicating that the sponge requires exposed habitat. The cover of corals and other sponges explained little variation in C. orientalis cover or distribution. The fastest increases in C. orientalis cover coincided with the lowest macroalgal cover and chlorophyll a concentration, highlighting the importance of macroalgal competition and local environmental conditions for this bioeroding sponge. Given the observed distribution and habitat preferences of C. orientalis, bioeroding sponges likely represent site-specific - rather than regional - threats to corals and reef accretion.

  2. North Jamaican Deep Fore-Reef Sponges

    NARCIS (Netherlands)

    Lehnert, Helmut; Soest, van R.W.M.

    1996-01-01

    An unexpectedly high amount of new species, revealed within only one hour of summarized bottom time, leads to the conclusion that the sponge fauna of the steep slopes of the deep fore-reef is still largely unknown. Four mixed gas dives at depths between 70 and 90 m, performed in May and June, 1993,

  3. Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals.

    Science.gov (United States)

    Loh, Tse-Lynn; McMurray, Steven E; Henkel, Timothy P; Vicente, Jan; Pawlik, Joseph R

    2015-01-01

    Consumer-mediated indirect effects at the community level are difficult to demonstrate empirically. Here, we show an explicit indirect effect of overfishing on competition between sponges and reef-building corals from surveys of 69 sites across the Caribbean. Leveraging the large-scale, long-term removal of sponge predators, we selected overfished sites where intensive methods, primarily fish-trapping, have been employed for decades or more, and compared them to sites in remote or marine protected areas (MPAs) with variable levels of enforcement. Sponge-eating fishes (angelfishes and parrotfishes) were counted at each site, and the benthos surveyed, with coral colonies scored for interaction with sponges. Overfished sites had >3 fold more overgrowth of corals by sponges, and mean coral contact with sponges was 25.6%, compared with 12.0% at less-fished sites. Greater contact with corals by sponges at overfished sites was mostly by sponge species palatable to sponge predators. Palatable species have faster rates of growth or reproduction than defended sponge species, which instead make metabolically expensive chemical defenses. These results validate the top-down conceptual model of sponge community ecology for Caribbean reefs, as well as provide an unambiguous justification for MPAs to protect threatened reef-building corals. An unanticipated outcome of the benthic survey component of this study was that overfished sites had lower mean macroalgal cover (23.1% vs. 38.1% for less-fished sites), a result that is contrary to prevailing assumptions about seaweed control by herbivorous fishes. Because we did not quantify herbivores for this study, we interpret this result with caution, but suggest that additional large-scale studies comparing intensively overfished and MPA sites are warranted to examine the relative impacts of herbivorous fishes and urchins on Caribbean reefs.

  4. 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.

  5. Discordance between morphological and molecular species boundaries among Caribbean species of the reef sponge Callyspongia

    OpenAIRE

    DeBiasse, Melissa B; Hellberg, Michael E

    2015-01-01

    Sponges are among the most species-rich and ecologically important taxa on coral reefs, yet documenting their diversity is difficult due to the simplicity and plasticity of their morphological characters. Genetic attempts to identify species are hampered by the slow rate of mitochondrial sequence evolution characteristic of sponges and some other basal metazoans. Here we determine species boundaries of the Caribbean coral reef sponge genus Callyspongia using a multilocus, model-based approach...

  6. 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

  7. Productivity and abundance of large sponge populations on Flinders Reef flats, Coral Sea

    Science.gov (United States)

    Wilkinson, Clive R.

    1987-04-01

    Large populations of flattened sponges with cyanobacterial symbionts were observed on the shallow reef-flats of the Flinders Reefs, Coral Sea. Estimates of these populations indicated as many as 60 individuals with a total wet biomass of 1.2 kg per m2 in some areas. Along a metre wide transect across 1.3 km of reef flat the population was estimated at 530 kg wet weight sponge (mean 411 g m-2). The four prominent species had instantaneous P/R ratios between 1.3 and 1.8 at optimum light such that photosynthetic productivity was calculated to provide between 61 and 80% of sponge energy requirements in summer and 48 to 64% in winter. While such sponge beds are a prominent feature of these reefs, they appear to contribute less than 10% of gross reef-flat productivity.

  8. Larval Behaviours and Their Contribution to the Distribution of the Intertidal Coral Reef Sponge Carteriospongia foliascens

    Science.gov (United States)

    Abdul Wahab, Muhammad Azmi; de Nys, Rocky; Webster, Nicole; Whalan, Steve

    2014-01-01

    Sponges (Phylum Porifera) are an evolutionary and ecologically significant group; however information on processes influencing sponge population distributions is surprisingly limited. Carteriospongia foliascens is a common Indo-Pacific sponge, which has been reported from the intertidal to the mesophotic. Interestingly, the distribution of C. foliascens at inshore reefs of the Great Barrier Reef is restricted to the intertidal with no individuals evident in adjacent subtidal habitats. The abundance of C. foliascens and substrate availability was first quantified to investigate the influence of substrate limitation on adult distribution. Pre-settlement processes of larval spawning, swimming speeds, phototaxis, vertical migration, and settlement to intertidal and subtidal substrate cues were also quantified. Notably, suitable settlement substrate (coral rubble) was not limiting in subtidal habitats. C. foliascens released up to 765 brooded larvae sponge−1 day−1 during the day, with larvae (80%±5.77) being negatively phototactic and migrating to the bottom within 40 minutes from release. Subsequently, larvae (up to 58.67%±2.91) migrated to the surface after the loss of the daylight cue (nightfall), and after 34 h post-release >98.67% (±0.67) of larvae had adopted a benthic habit regardless of light conditions. Intertidal and subtidal biofilms initiated similar settlement responses, inducing faster (as early 6 h post-release) and more successful metamorphosis (>60%) than unconditioned surfaces. C. foliascens has a high larval supply and larval behaviours that support recruitment to the subtidal. The absence of C. foliascens in subtidal habitats at inshore reefs is therefore proposed to be a potential consequence of post-settlement mortalities. PMID:24853091

  9. Chemical defenses and resource trade-offs structure sponge communities on Caribbean coral reefs.

    Science.gov (United States)

    Loh, Tse-Lynn; Pawlik, Joseph R

    2014-03-18

    Ecological studies have rarely been performed at the community level across a large biogeographic region. Sponges are now the primary habitat-forming organisms on Caribbean coral reefs. Recent species-level investigations have demonstrated that predatory fishes (angelfishes and some parrotfishes) differentially graze sponges that lack chemical defenses, while co-occurring, palatable species heal, grow, reproduce, or recruit at faster rates than defended species. Our prediction, based on resource allocation theory, was that predator removal would result in a greater proportion of palatable species in the sponge community on overfished reefs. We tested this prediction by performing surveys of sponge and fish community composition on reefs having different levels of fishing intensity across the Caribbean. A total of 109 sponge species was recorded from 69 sites, with the 10 most common species comprising 51.0% of sponge cover (3.6-7.7% per species). Nonmetric multidimensional scaling indicated that the species composition of sponge communities depended more on the abundance of sponge-eating fishes than geographic location. Across all sites, multiple-regression analyses revealed that spongivore abundance explained 32.8% of the variation in the proportion of palatable sponges, but when data were limited to geographically adjacent locations with strongly contrasting levels of fishing pressure (Cayman Islands and Jamaica; Curaçao, Bonaire, and Martinique), the adjusted R(2) values were much higher (76.5% and 94.6%, respectively). Overfishing of Caribbean coral reefs, particularly by fish trapping, removes sponge predators and is likely to result in greater competition for space between faster-growing palatable sponges and endangered reef-building corals.

  10. CHAMBERED HEXACTINELLID SPONGES FROM UPPER TRIASSIC(NORIAN-RHAETIAN? REEFS OF NAYBAND FORMATION IN CENTRAL IRAN

    Directory of Open Access Journals (Sweden)

    B. SENOWBARI-DARYAN

    2012-07-01

    Full Text Available This paper describes several chambered hexactinellid sponges, including Casearia iranica n.sp., C. vezvanensis n. sp., C. delijanensis n. sp., Esfahanella magna gen. n. n. sp., and E. parva gen. n. n. sp. from reefs of the Upper Triassic (Norian-Rhaetian Nayband Formation exposed south of the town of Delijan in central Iran. The relative abundance of chambered and non-chambered hexactinellid sponges at this locality - as compared to hypercalcified representatives - highlight the importance of this group of sponges in reef and reefal limestones in central and east Tethys (China, Caucasia, Iran. 

  11. Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up.

    Science.gov (United States)

    Pawlik, Joseph R; Loh, Tse-Lynn; McMurray, Steven E; Finelli, Christopher M

    2013-01-01

    Caribbean coral reefs have been transformed in the past few decades with the demise of reef-building corals, and sponges are now the dominant habitat-forming organisms on most reefs. Competing hypotheses propose that sponge communities are controlled primarily by predatory fishes (top-down) or by the availability of picoplankton to suspension-feeding sponges (bottom-up). We tested these hypotheses on Conch Reef, off Key Largo, Florida, by placing sponges inside and outside predator-excluding cages at sites with less and more planktonic food availability (15 m vs. 30 m depth). There was no evidence of a bottom-up effect on the growth of any of 5 sponge species, and 2 of 5 species grew more when caged at the shallow site with lower food abundance. There was, however, a strong effect of predation by fishes on sponge species that lacked chemical defenses. Sponges with chemical defenses grew slower than undefended species, demonstrating a resource trade-off between growth and the production of secondary metabolites. Surveys of the benthic community on Conch Reef similarly did not support a bottom-up effect, with higher sponge cover at the shallower depth. We conclude that the structure of sponge communities on Caribbean coral reefs is primarily top-down, and predict that removal of sponge predators by overfishing will shift communities toward faster-growing, undefended species that better compete for space with threatened reef-building corals.

  12. Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up.

    Directory of Open Access Journals (Sweden)

    Joseph R Pawlik

    Full Text Available Caribbean coral reefs have been transformed in the past few decades with the demise of reef-building corals, and sponges are now the dominant habitat-forming organisms on most reefs. Competing hypotheses propose that sponge communities are controlled primarily by predatory fishes (top-down or by the availability of picoplankton to suspension-feeding sponges (bottom-up. We tested these hypotheses on Conch Reef, off Key Largo, Florida, by placing sponges inside and outside predator-excluding cages at sites with less and more planktonic food availability (15 m vs. 30 m depth. There was no evidence of a bottom-up effect on the growth of any of 5 sponge species, and 2 of 5 species grew more when caged at the shallow site with lower food abundance. There was, however, a strong effect of predation by fishes on sponge species that lacked chemical defenses. Sponges with chemical defenses grew slower than undefended species, demonstrating a resource trade-off between growth and the production of secondary metabolites. Surveys of the benthic community on Conch Reef similarly did not support a bottom-up effect, with higher sponge cover at the shallower depth. We conclude that the structure of sponge communities on Caribbean coral reefs is primarily top-down, and predict that removal of sponge predators by overfishing will shift communities toward faster-growing, undefended species that better compete for space with threatened reef-building corals.

  13. Barrier Methods of Birth Control: Spermicide, Condom, Sponge, Diaphragm, and Cervical Cap

    Science.gov (United States)

    ... ACOG Barrier Methods of Birth Control: Spermicide, Condom, Sponge, Diaphragm, and Cervical Cap Home For Patients Search ... Format Barrier Methods of Birth Control: Spermicide, Condom, Sponge, Diaphragm, and Cervical Cap Contraception What are barrier ...

  14. Chemical defenses and resource trade-offs structure sponge communities on Caribbean coral reefs

    OpenAIRE

    Loh, Tse-Lynn; Pawlik, Joseph R.

    2014-01-01

    Chemical defenses are known to protect some species from consumers, but it is often difficult to detect this advantage at the community or ecosystem levels because of the complexity of abiotic and biotic factors that influence species abundances. We surveyed the community of sponges and sponge predators (angelfishes and parrotfishes) on coral reefs across the Caribbean ranging from heavily overfished sites to protected marine reserves. High predator abundance correlated with high abundance of...

  15. The effects of coastal development on sponge abundance, diversity, and community composition on Jamaican coral reefs.

    Science.gov (United States)

    Stubler, Amber D; Duckworth, Alan R; Peterson, Bradley J

    2015-07-15

    Over the past decade, development along the northern coast of Jamaica has accelerated, resulting in elevated levels of sedimentation on adjacent reefs. To understand the effects of this development on sponge community dynamics, we conducted surveys at three locations with varying degrees of adjacent coastal development to quantify species richness, abundance and diversity at two depths (8-10 m and 15-18 m). Sediment accumulation rate, total suspended solids and other water quality parameters were also quantified. The sponge community at the location with the least coastal development and anthropogenic influence was often significantly different from the other two locations, and exhibited higher sponge abundance, richness, and diversity. Sponge community composition and size distribution were statistically different among locations. This study provides correlative evidence that coastal development affects aspects of sponge community ecology, although the precise mechanisms are still unclear. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Biological characterisation of Haliclona (?gellius) sp.: sponge and associated microorganisms.

    NARCIS (Netherlands)

    Sipkema, D.; Holmes, B.; Nichols, S.A.; Blanch, H.W.

    2009-01-01

    We have characterised the northern Pacific undescribed sponge Haliclona (?gellius) sp. based on rDNA of the sponge and its associated microorganisms. The sponge is closely related to Amphimedon queenslandica from the Great Barrier Reef as the near-complete 18S rDNA sequences of both sponges were

  17. Microbial and sponge loops modify fish production in phase-shifting coral reefs.

    Science.gov (United States)

    Silveira, Cynthia B; Silva-Lima, Arthur W; Francini-Filho, Ronaldo B; Marques, Jomar S M; Almeida, Marcelo G; Thompson, Cristiane C; Rezende, Carlos E; Paranhos, Rodolfo; Moura, Rodrigo L; Salomon, Paulo S; Thompson, Fabiano L

    2015-10-01

    Shifts from coral to algae dominance of corals reefs have been correlated to fish biomass loss and increased microbial metabolism. Here we investigated reef benthic and planktonic primary production, benthic dissolved organic carbon (DOC) release and bacterial growth efficiency in the Abrolhos Bank, South Atlantic. Benthic DOC release rates are higher while water column bacterial growth efficiency is lower at impacted reefs. A trophic model based on the benthic and planktonic primary production was able to predict the observed relative fish biomass in healthy reefs. In contrast, in impacted reefs, the observed omnivorous fish biomass is higher, while that of the herbivorous/coralivorous fish is lower than predicted by the primary production-based model. Incorporating recycling of benthic-derived carbon in the model through microbial and sponge loops explains the difference and predicts the relative fish biomass in both reef types. Increased benthic carbon release rates and bacterial carbon metabolism, but decreased bacterial growth efficiency could lead to carbon losses through respiration and account for the uncoupling of benthic and fish production in phase-shifting reefs. Carbon recycling by microbial and sponge loops seems to promote an increase of small-bodied fish productivity in phase-shifting coral reefs. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Exploring seascape genetics and kinship in the reef sponge Stylissa carteri in the Red Sea

    KAUST Repository

    Giles, Emily C.; Saenz Agudelo, Pablo; Hussey, Nigel E.; Ravasi, Timothy; Berumen, Michael L.

    2015-01-01

    A main goal of population geneticists is to study patterns of gene flow to gain a better understanding of the population structure in a given organism. To date most efforts have been focused on studying gene flow at either broad scales to identify barriers to gene flow and isolation by distance or at fine spatial scales in order to gain inferences regarding reproduction and local dispersal. Few studies have measured connectivity at multiple spatial scales and have utilized novel tools to test the influence of both environment and geography on shaping gene flow in an organism. Here a seascape genetics approach was used to gain insight regarding geographic and ecological barriers to gene flow of a common reef sponge, Stylissa carteri in the Red Sea. Furthermore, a small-scale (<1 km) analysis was also conducted to infer reproductive potential in this organism. At the broad scale, we found that sponge connectivity is not structured by geography alone, but rather, genetic isolation in the southern Red Sea correlates strongly with environmental heterogeneity. At the scale of a 50-m transect, spatial autocorrelation analyses and estimates of full-siblings revealed that there is no deviation from random mating. However, at slightly larger scales (100–200 m) encompassing multiple transects at a given site, a greater proportion of full-siblings was found within sites versus among sites in a given location suggesting that mating and/or dispersal are constrained to some extent at this spatial scale. This study adds to the growing body of literature suggesting that environmental and ecological variables play a major role in the genetic structure of marine invertebrate populations.

  19. Exploring seascape genetics and kinship in the reef sponge Stylissa carteri in the Red Sea

    KAUST Repository

    Giles, Emily C.

    2015-06-01

    A main goal of population geneticists is to study patterns of gene flow to gain a better understanding of the population structure in a given organism. To date most efforts have been focused on studying gene flow at either broad scales to identify barriers to gene flow and isolation by distance or at fine spatial scales in order to gain inferences regarding reproduction and local dispersal. Few studies have measured connectivity at multiple spatial scales and have utilized novel tools to test the influence of both environment and geography on shaping gene flow in an organism. Here a seascape genetics approach was used to gain insight regarding geographic and ecological barriers to gene flow of a common reef sponge, Stylissa carteri in the Red Sea. Furthermore, a small-scale (<1 km) analysis was also conducted to infer reproductive potential in this organism. At the broad scale, we found that sponge connectivity is not structured by geography alone, but rather, genetic isolation in the southern Red Sea correlates strongly with environmental heterogeneity. At the scale of a 50-m transect, spatial autocorrelation analyses and estimates of full-siblings revealed that there is no deviation from random mating. However, at slightly larger scales (100–200 m) encompassing multiple transects at a given site, a greater proportion of full-siblings was found within sites versus among sites in a given location suggesting that mating and/or dispersal are constrained to some extent at this spatial scale. This study adds to the growing body of literature suggesting that environmental and ecological variables play a major role in the genetic structure of marine invertebrate populations.

  20. Novel polymorphic microsatellite markers developed for a common reef sponge, Stylissa carteri

    KAUST Repository

    Giles, E.C.; Saenz-Agudelo, P.; Berumen, Michael L.; Ravasi, Timothy

    2013-01-01

    Despite the ubiquitous role sponges play in reef ecosystem dynamics, little is known about population-level connectivity in these organisms. The general field of population genetics in sponges remains in its infancy. To date, microsatellite markers have only been developed for few sponge species and no sponge population genetics studies using microsatellites have been conducted in the Red Sea. Here, with the use of next-generation sequencing, we characterize 12 novel polymorphic loci for the common reef sponge, Stylissa carteri. The number of alleles per loci ranged between three and eight. Observed heterozygosity frequencies (Ho) ranged from 0.125 to 0.870, whereas expected (He) heterozygosity frequencies ranged from 0.119 to 0.812. Only one locus showed consistent deviations from Hardy-Weinberg equilibrium (HWE) in both populations and two loci consistently showed the possible presence of null alleles. No significant linkage disequilibrium was detected for any pairs of loci. These microsatellites will be of use for numerous ecological studies focused on this common and abundant sponge. 2013 The Author(s).

  1. Novel polymorphic microsatellite markers developed for a common reef sponge, Stylissa carteri

    KAUST Repository

    Giles, E.C.

    2013-04-04

    Despite the ubiquitous role sponges play in reef ecosystem dynamics, little is known about population-level connectivity in these organisms. The general field of population genetics in sponges remains in its infancy. To date, microsatellite markers have only been developed for few sponge species and no sponge population genetics studies using microsatellites have been conducted in the Red Sea. Here, with the use of next-generation sequencing, we characterize 12 novel polymorphic loci for the common reef sponge, Stylissa carteri. The number of alleles per loci ranged between three and eight. Observed heterozygosity frequencies (Ho) ranged from 0.125 to 0.870, whereas expected (He) heterozygosity frequencies ranged from 0.119 to 0.812. Only one locus showed consistent deviations from Hardy-Weinberg equilibrium (HWE) in both populations and two loci consistently showed the possible presence of null alleles. No significant linkage disequilibrium was detected for any pairs of loci. These microsatellites will be of use for numerous ecological studies focused on this common and abundant sponge. 2013 The Author(s).

  2. Exploring seascape genetics and kinship in the reef sponge Stylissa carteri in the Red Sea

    Science.gov (United States)

    Giles, Emily C; Saenz-Agudelo, Pablo; Hussey, Nigel E; Ravasi, Timothy; Berumen, Michael L

    2015-01-01

    A main goal of population geneticists is to study patterns of gene flow to gain a better understanding of the population structure in a given organism. To date most efforts have been focused on studying gene flow at either broad scales to identify barriers to gene flow and isolation by distance or at fine spatial scales in order to gain inferences regarding reproduction and local dispersal. Few studies have measured connectivity at multiple spatial scales and have utilized novel tools to test the influence of both environment and geography on shaping gene flow in an organism. Here a seascape genetics approach was used to gain insight regarding geographic and ecological barriers to gene flow of a common reef sponge, Stylissa carteri in the Red Sea. Furthermore, a small-scale (Red Sea correlates strongly with environmental heterogeneity. At the scale of a 50-m transect, spatial autocorrelation analyses and estimates of full-siblings revealed that there is no deviation from random mating. However, at slightly larger scales (100–200 m) encompassing multiple transects at a given site, a greater proportion of full-siblings was found within sites versus among sites in a given location suggesting that mating and/or dispersal are constrained to some extent at this spatial scale. This study adds to the growing body of literature suggesting that environmental and ecological variables play a major role in the genetic structure of marine invertebrate populations. PMID:26257865

  3. Clionid sponge surveys on the Florida Reef Tract suggest land-based nutrient inputs

    International Nuclear Information System (INIS)

    Ward-Paige, Christine A.; Risk, Michael J.; Sherwood, Owen A.; Jaap, Walter C.

    2005-01-01

    Bioerosion by Cliona delitrix and Cliona lampa was assessed at 43 sites along the Florida Reef Tract, USA, in the summer of 2001. Sponge abundances were estimated using rapid visual assessment. Tissue samples of sponges were taken for analysis of δ 15 N. Comparison samples were taken from Belize. Annual trends in sponge abundance were estimated from archived videos covering the period from 1996 to 2001. Sites with the greatest boring sponge size and cover were in the Backcountry and Lower Keys, where total nitrogen, ammonium, and δ 15 N levels were highest. The sites with the largest relative increase of C. delitrix and C. lampa over the 5 year period were in the Upper Keys, where the greatest relative decline in stony coral cover has occurred. Florida sponge δ 15 N values were 5.2(±0.1)%, suggesting the influence of human waste; in comparison, offshore Belize samples were 2.1(±0.1)%. These results suggest sewage contamination of the Florida Reef Tract, shifting the carbonate balance from construction to destruction

  4. Chemical and mechanical bioerosion of boring sponges from Mexican Pacific coral reefs.

    Science.gov (United States)

    Nava, Héctor; Carballo, José Luis

    2008-09-01

    Species richness (S) and frequency of invasion (IF) by boring sponges on living colonies of Pocillopora spp. from National Park Isla Isabel (México, East Pacific Ocean) are presented. Twelve species belonging to the genera Aka, Cliona, Pione, Thoosa and Spheciospongia were found, and 56% of coral colonies were invaded by boring sponges, with Cliona vermifera Hancock 1867 being the most abundant species (30%). Carbonate dissolution rate and sediment production were quantified for C. vermifera and Cliona flavifodina Rützler 1974. Both species exhibited similar rates of calcium carbonate (CaCO3) dissolution (1.2+/-0.4 and 0.5+/-0.2 kg CaCO3 m(-2) year(-1), respectively, mean +/- s.e.m.), and sediment production (3.3+/-0.6 and 4.6+/-0.5 kg CaCO3 m(-2) year(-1)), resulting in mean bioerosion rates of 4.5+/-0.9 and 5.1+/-0.5 kg CaCO3 m(-2) year(-1), respectively. These bioerosion rates are close to previous records of coral calcification per unit of area, suggesting that sponge bioerosion alone can promote disequilibrium in the reef accretion/destruction ratio in localities that are heavily invaded by boring sponges. The proportion of dissolved material by C. vermifera and C. flavifodina (27 and 10.2%, respectively) confirms that chemical bioerosion plays an important role in sponge bioerosion and in the CaCO3 cycle in coral reefs.

  5. Clionid sponge surveys on the Florida Reef Tract suggest land-based nutrient inputs

    Energy Technology Data Exchange (ETDEWEB)

    Ward-Paige, Christine A. [School of Geography and Geology, McMaster University, Hamilton, ON, L8S 4M1 (Canada)]. E-mail: cwardpai@dal.ca; Risk, Michael J. [School of Geography and Geology, McMaster University, Hamilton, ON, L8S 4M1 (Canada); Sherwood, Owen A. [Department of Earth Sciences, Dalhousie University, Halifax, NS, B3H 4J1 (Canada); Jaap, Walter C. [Florida Marine Research Institute, St. Petersburg, Florida (United States)

    2005-07-01

    Bioerosion by Cliona delitrix and Cliona lampa was assessed at 43 sites along the Florida Reef Tract, USA, in the summer of 2001. Sponge abundances were estimated using rapid visual assessment. Tissue samples of sponges were taken for analysis of {delta} {sup 15}N. Comparison samples were taken from Belize. Annual trends in sponge abundance were estimated from archived videos covering the period from 1996 to 2001. Sites with the greatest boring sponge size and cover were in the Backcountry and Lower Keys, where total nitrogen, ammonium, and {delta} {sup 15}N levels were highest. The sites with the largest relative increase of C. delitrix and C. lampa over the 5 year period were in the Upper Keys, where the greatest relative decline in stony coral cover has occurred. Florida sponge {delta} {sup 15}N values were 5.2({+-}0.1)%, suggesting the influence of human waste; in comparison, offshore Belize samples were 2.1({+-}0.1)%. These results suggest sewage contamination of the Florida Reef Tract, shifting the carbonate balance from construction to destruction.

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

    KAUST Repository

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

    2016-01-01

    The Great Barrier Reef (GBR) is founded on reef-building corals. Corals build their exoskeleton with aragonite, but ocean acidification is lowering the aragonite saturation state of seawater (Ωa). The downscaling of ocean acidification projections

  7. Clones or clans: the genetic structure of a deep-sea sponge, Aphrocallistes vastus, in unique sponge reefs of British Columbia, Canada.

    Science.gov (United States)

    Brown, Rachel R; Davis, Corey S; Leys, Sally P

    2017-02-01

    Understanding patterns of reproduction, dispersal and recruitment in deep-sea communities is increasingly important with the need to manage resource extraction and conserve species diversity. Glass sponges are usually found in deep water (>1000 m) worldwide but form kilometre-long reefs on the continental shelf of British Columbia and Alaska that are under threat from trawling and resource exploration. Due to their deep-water habitat, larvae have not yet been found and the level of genetic connectivity between reefs and nonreef communities is unknown. The genetic structure of Aphrocallistes vastus, the primary reef-building species in the Strait of Georgia (SoG) British Columbia, was studied using single nucleotide polymorphisms (SNPs). Pairwise comparisons of multilocus genotypes were used to assess whether sexual reproduction is common. Structure was examined 1) between individuals in reefs, 2) between reefs and 3) between sites in and outside the SoG. Sixty-seven SNPs were genotyped in 91 samples from areas in and around the SoG, including four sponge reefs and nearby nonreef sites. The results show that sponge reefs are formed through sexual reproduction. Within a reef and across the SoG basin, the genetic distance between individuals does not vary with geographic distance (r = -0.005 to 0.014), but populations within the SoG basin are genetically distinct from populations in Barkley Sound, on the west coast of Vancouver Island. Population structure was seen across all sample sites (global F ST  = 0.248), especially between SoG and non-SoG locations (average pairwise F ST  = 0.251). Our results suggest that genetic mixing occurs across sponge reefs via larvae that disperse widely. © 2016 John Wiley & Sons Ltd.

  8. Discordance between morphological and molecular species boundaries among Caribbean species of the reef sponge Callyspongia.

    Science.gov (United States)

    DeBiasse, Melissa B; Hellberg, Michael E

    2015-02-01

    Sponges are among the most species-rich and ecologically important taxa on coral reefs, yet documenting their diversity is difficult due to the simplicity and plasticity of their morphological characters. Genetic attempts to identify species are hampered by the slow rate of mitochondrial sequence evolution characteristic of sponges and some other basal metazoans. Here we determine species boundaries of the Caribbean coral reef sponge genus Callyspongia using a multilocus, model-based approach. Based on sequence data from one mitochondrial (COI), one ribosomal (28S), and two single-copy nuclear protein-coding genes, we found evolutionarily distinct lineages were not concordant with current species designations in Callyspongia. While C. fallax,C. tenerrima, and C. plicifera were reciprocally monophyletic, four taxa with different morphologies (C. armigera,C. longissima,C. eschrichtii, and C. vaginalis) formed a monophyletic group and genetic distances among these taxa overlapped distances within them. A model-based method of species delimitation supported collapsing these four into a single evolutionary lineage. Variation in spicule size among these four taxa was partitioned geographically, not by current species designations, indicating that in Callyspongia, these key taxonomic characters are poor indicators of genetic differentiation. Taken together, our results suggest a complex relationship between morphology and species boundaries in sponges.

  9. High spatial variability of coral, sponges and gorgonian assemblages in a well preserved reef

    Directory of Open Access Journals (Sweden)

    Patricia González-Díaz

    2010-06-01

    Full Text Available The main goal of this research was to obtain baseline field data of the composition of sponges, corals, and gorgonian assemblages that can be used as a reference for future analyses of anthropogenic impact. We tested the hypothesis that relatively homogeneous and well preserved reef units can present notable natural variability in the composition of their communities which are unassociated with changes in land proximity or a human impact gradient. Research was carried out in July 2006 at Los Colorados reef, located in the northwestern region of Pinar del Río Province, Cuba at 12 sampling stations. The biotopes selected were crest, terrace edge and spur and grove. Ecological indicators were diversity of corals, species composition, density of corals, hydrocorals, gorgonians and sponges, and density of selected coral species. A total of 2659 colonies of scleractineans corals representing 36 species were counted. The most abundant species in the crest biotope were Millepora alcicornis, Acropora palmata and Porites astreoides; in the terrace edge and spur and grove, the most abundant species were Siderastrea siderea, Stephanocoenia intersepta, Porites astreoides, Agaricia agaricites and Montastraea cavernosa. We found differences among sites for several indicators (e.g. density of corals, sponges and gorgonians and for selected species, but they could not be associated to any gradient of land influence or human impact. Therefore, sites inside a relatively homogeneous reef unit can present notable natural differences in the composition of their communities. Rev. Biol. Trop. 58 (2: 621-634. Epub 2010 June 02.

  10. High spatial variability of coral, sponges and gorgonian assemblages in a well preserved reef.

    Science.gov (United States)

    González-Díaz, Patricia; González-Sansón, Gaspar; Alvarez Fernández, Sergio; Perera Pérez, Orlando

    2010-06-01

    The main goal of this research was to obtain baseline field data of the composition of sponges, corals, and gorgonian assemblages that can be used as a reference for future analyses of anthropogenic impact. We tested the hypothesis that relatively homogeneous and well preserved reef units can present notable natural variability in the composition of their communities which are unassociated with changes in land proximity or a human impact gradient. Research was carried out in July 2006 at Los Colorados reef, located in the northwestern region of Pinar del Río Province, Cuba at 12 sampling stations. The biotopes selected were crest, terrace edge and spur and grove. Ecological indicators were diversity of corals, species composition, density of corals, hydrocorals, gorgonians and sponges, and density of selected coral species. A total of 2659 colonies of scleractineans corals representing 36 species were counted. The most abundant species in the crest biotope were Millepora alcicornis, Acropora palmata and Porites astreoides; in the terrace edge and spur and grove, the most abundant species were Siderastrea siderea, Stephanocoenia intersepta, Porites astreoides, Agaricia agaricites and Montastraea cavernosa. We found differences among sites for several indicators (e.g. density of corals, sponges and gorgonians and for selected species), but they could not be associated to any gradient of land influence or human impact. Therefore, sites inside a relatively homogeneous reef unit can present notable natural differences in the composition of their communities.

  11. Bacterial diversity associated with Cinachyra cavernosa and Haliclona pigmentifera, cohabiting sponges in the coral reef ecosystem of Gulf of Mannar, southeast coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Jasmin, C; Anas, A.; Nair, S.

    1.97). UniFrac analysis confirmed the difference in bacterial diversity of the two sponge species and also between the sponges and the reef water(p<0.001). The results of our study restate the existence of a host driven force in shaping the sponge...

  12. Sponge assemblage of some Upper Permian reef limestones from Phrae province (Northern Thailand

    Directory of Open Access Journals (Sweden)

    Baba Senowbari-Daryan

    1994-12-01

    Full Text Available The sponge fauna of uppermost Permian reef or reefal limestones of the Phrae province in northern Thailand include representatives of hexactinellida, sclerospongea,"sphinctozoans", and "inozoans". The "sphinctozoans" and "inozoans"are described in detail. Following taxa are new:"Sphinctozoans": Phraethalamia tubulara n. gen., n. sp., Ambithalamia pérmican. gen., n. sp."Inozoans": Bisiphonella tubulara n. sp., Solutossaspongia crassimuralis n.gen., n. sp.The genus name Belyaevaspongia nom. nov. is proposed for PolysiphonellaBelyaeva, 1991 (in Boiko et al., 1991, non Polysiphonella Russo, 1981.

  13. Bacterial Diversity Associated with Cinachyra cavernosa and Haliclona pigmentifera, Cohabiting Sponges in the Coral Reef Ecosystem of Gulf of Mannar, Southeast Coast of India.

    Directory of Open Access Journals (Sweden)

    C Jasmin

    Full Text Available Sponges are abundant, diverse and functionally important organisms of coral reef ecosystems. Sponge-associated microorganisms have been receiving greater attention because of their significant contribution to sponge biomass, biogeochemical cycles and biotechnological potentials. However, our understanding of the sponge microbiome is limited to a few species of sponges from restricted geographical locations. Here, we report for the first time the bacterial diversity of two cohabiting sponges, viz. Cinachyra cavernosa and Haliclona pigmentifera, as well as that in the ambient water from the coral reef ecosystems of the Gulf of Mannar, located along the southeast coast of India. Two hundred and fifty two clones in the 16S rRNA gene library of these sponges were grouped into eight distinct phyla, of which four belonged to the core group that are associated only with sponges. Phylogenetic analysis of the core bacteria showed close affinity to other sponge-associated bacteria from different geographical locations. γ-Proteobacteria, Chloroflexi, Planctomycetes and Deferribacter were the core groups in C. cavernosa while β and δ-Proteobacteria performed this role in H. pigmentifera. We observed greater OTU diversity for C. cavernosa (Hǀ 2.07 compared to H. pigmentifera (Hǀ 1.97. UniFrac analysis confirmed the difference in bacterial diversity of the two sponge species and also between the sponges and the reef water (p<0.001. The results of our study restate the existence of a host driven force in shaping the sponge microbiome.

  14. 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

  15. Wave attenuation over the Great Barrier Reef matrix

    NARCIS (Netherlands)

    Gallop, S.; Young, I.; Ranasinghe, Ranasinghe W M R J B; Durrant, T.; Haigh, I.; Mynett, Arthur

    2015-01-01

    This is the first large-scale study of the influence of an offshore reef matrix on wave transmission. The focus was on the Great Barrier Reef (GBR), Australia, utilizing a 16 yr-record of wave height, from seven satellite altimeters. Within the GBR matrix, wave height is not strongly dependent on

  16. Climate change and the Great Barrier Reef

    International Nuclear Information System (INIS)

    Johnson, Johanna; Marshall, Paul

    2007-01-01

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

  17. 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...

  18. Distribution and covering percentage of sponge (Porifera in different coral reef condition and depth in Barranglompo Island, South Sulawesi

    Directory of Open Access Journals (Sweden)

    SUHARYANTO

    2008-07-01

    Full Text Available In 1996, four specieses of sponge namely Auletta sp., Callyspongia pseudoreticulata, Callyspongia sp., and Halichondria sp. have been potentially identified as bacteriside for fishery commodities. Nevertheless, information on sponge distribution, its covering percentage, and its habitate are still very little. Observation on distribution and abundance of sponge was conducted in the Southeastern and the Northwestern part of Barranglompo Island, South Sulawesi, using scuba diving set and under water writting tools. At first, coral reef condition in 3 and 10 m depths up to 100 m length of shore line were observed in both stations, using “lifeform method”. Then distribution and covering percentage of sponge, biotic and abiotic factor in 3, 6, 9, and 12 m depths in both stations were examined using “square transect method”. The result showed that different coral reef condition qualitatively causes different of sponge species distribution, but quantitatively not significantly different (P>0,05 on its covering percentage. It was also found that generally sponge grows better at the dead coral where no other biotic organism around.

  19. The importance of sponges and mangroves in supporting fish communities on degraded coral reefs in Caribbean Panama.

    Science.gov (United States)

    Seemann, Janina; Yingst, Alexandra; Stuart-Smith, Rick D; Edgar, Graham J; Altieri, Andrew H

    2018-01-01

    Fish communities associated with coral reefs worldwide are threatened by habitat degradation and overexploitation. We assessed coral reefs, mangrove fringes, and seagrass meadows on the Caribbean coast of Panama to explore the influences of their proximity to one another, habitat cover, and environmental characteristics in sustaining biomass, species richness and trophic structure of fish communities in a degraded tropical ecosystem. We found 94% of all fish across all habitat types were of small body size (≤10 cm), with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes) and Gobiidae (gobies). Total fish biomass was very low, with the trend of small fishes from low trophic levels over-represented, and top predators under-represented, relative to coral reefs elsewhere in the Caribbean. For example, herbivorous fishes comprised 27% of total fish biomass in Panama relative to 10% in the wider Caribbean, and the small parrotfish Scarus iseri comprised 72% of the parrotfish biomass. We found evidence that non-coral biogenic habitats support reef-associated fish communities. In particular, the abundance of sponges on a given reef and proximity of mangroves were found to be important positive correlates of reef fish species richness, biomass, abundance and trophic structure. Our study indicates that a diverse fish community can persist on degraded coral reefs, and that the availability and arrangement within the seascape of other habitat-forming organisms, including sponges and mangroves, is critical to the maintenance of functional processes in such ecosystems.

  20. Benthic foraminifera baseline assemblages from a coastal nearshore reef complex on the central Great Barrier Reef

    Science.gov (United States)

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

    2016-04-01

    Declining water quality due to river catchment modification since European settlement (c. 1850 A.D.) represents a major threat to the health of coral reefs on Australia's Great Barrier Reef (GBR), particularly for those located in the coastal waters of the GBR's inner-shelf. These nearshore reefs are widely perceived to be most susceptible to declining water quality owing to their close proximity to river point sources. Despite this, nearshore reefs have been relatively poorly studied with the impacts and magnitudes of environmental degradation still remaining unclear. This is largely due to ongoing debates concerning the significance of increased sediment yields against naturally high background sedimentary regimes. Benthic foraminifera are increasingly used as tools for monitoring environmental and ecological change on coral reefs. On the GBR, the majority of studies have focussed on the spatial distributions of contemporary benthic foraminiferal assemblages. While baseline assemblages from other environments (e.g. inshore reefs and mangroves) have been described, very few records exist for nearshore reefs. Here, we present preliminary results from the first palaeoecological study of foraminiferal assemblages of nearshore reefs on the central GBR. Cores were recovered from the nearshore reef complex at Paluma Shoals using percussion techniques. Recovery was 100%, capturing the entire Holocene reef sequence of the selected reef structures. Radiocarbon dating and subsequent age-depth modelling techniques were used to identify reef sequences pre-dating European settlement. Benthic foraminifera assemblages were reconstructed from the identified sequences to establish pre-European ecological baselines with the aim of providing a record of foraminiferal distribution during vertical reef accretion and against which contemporary ecological change may be assessed.

  1. Connectivity and systemic resilience of the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Karlo Hock

    2017-11-01

    Full Text Available Australia's iconic Great Barrier Reef (GBR continues to suffer from repeated impacts of cyclones, coral bleaching, and outbreaks of the coral-eating crown-of-thorns starfish (COTS, losing much of its coral cover in the process. This raises the question of the ecosystem's systemic resilience and its ability to rebound after large-scale population loss. Here, we reveal that around 100 reefs of the GBR, or around 3%, have the ideal properties to facilitate recovery of disturbed areas, thereby imparting a level of systemic resilience and aiding its continued recovery. These reefs (1 are highly connected by ocean currents to the wider reef network, (2 have a relatively low risk of exposure to disturbances so that they are likely to provide replenishment when other reefs are depleted, and (3 have an ability to promote recovery of desirable species but are unlikely to either experience or spread COTS outbreaks. The great replenishment potential of these 'robust source reefs', which may supply 47% of the ecosystem in a single dispersal event, emerges from the interaction between oceanographic conditions and geographic location, a process that is likely to be repeated in other reef systems. Such natural resilience of reef systems will become increasingly important as the frequency of disturbances accelerates under climate change.

  2. Reduced diversity and high sponge abundance on a sedimented Indo-Pacific reef system: implications for future changes in environmental quality.

    Directory of Open Access Journals (Sweden)

    Abigail Powell

    Full Text Available Although coral reef health across the globe is declining as a result of anthropogenic impacts, relatively little is known of how environmental variability influences reef organisms other than corals and fish. Sponges are an important component of coral reef fauna that perform many important functional roles and changes in their abundance and diversity as a result of environmental change has the potential to affect overall reef ecosystem functioning. In this study, we examined patterns of sponge biodiversity and abundance across a range of environments to assess the potential key drivers of differences in benthic community structure. We found that sponge assemblages were significantly different across the study sites, but were dominated by one species Lamellodysidea herbacea (42% of all sponges patches recorded and that the differential rate of sediment deposition was the most important variable driving differences in abundance patterns. Lamellodysidea herbacea abundance was positively associated with sedimentation rates, while total sponge abundance excluding Lamellodysidea herbacea was negatively associated with rates of sedimentation. Overall variation in sponge assemblage composition was correlated with a number of variables although each variable explained only a small amount of the overall variation. Although sponge abundance remained similar across environments, diversity was negatively affected by sedimentation, with the most sedimented sites being dominated by a single sponge species. Our study shows how some sponge species are able to tolerate high levels of sediment and that any transition of coral reefs to more sedimented states may result in a shift to a low diversity sponge dominated system, which is likely to have subsequent effects on ecosystem functioning.

  3. Reduced Diversity and High Sponge Abundance on a Sedimented Indo-Pacific Reef System: Implications for Future Changes in Environmental Quality

    Science.gov (United States)

    Powell, Abigail; Smith, David J.; Hepburn, Leanne J.; Jones, Timothy; Berman, Jade; Jompa, Jamaluddin; Bell, James J.

    2014-01-01

    Although coral reef health across the globe is declining as a result of anthropogenic impacts, relatively little is known of how environmental variability influences reef organisms other than corals and fish. Sponges are an important component of coral reef fauna that perform many important functional roles and changes in their abundance and diversity as a result of environmental change has the potential to affect overall reef ecosystem functioning. In this study, we examined patterns of sponge biodiversity and abundance across a range of environments to assess the potential key drivers of differences in benthic community structure. We found that sponge assemblages were significantly different across the study sites, but were dominated by one species Lamellodysidea herbacea (42% of all sponges patches recorded) and that the differential rate of sediment deposition was the most important variable driving differences in abundance patterns. Lamellodysidea herbacea abundance was positively associated with sedimentation rates, while total sponge abundance excluding Lamellodysidea herbacea was negatively associated with rates of sedimentation. Overall variation in sponge assemblage composition was correlated with a number of variables although each variable explained only a small amount of the overall variation. Although sponge abundance remained similar across environments, diversity was negatively affected by sedimentation, with the most sedimented sites being dominated by a single sponge species. Our study shows how some sponge species are able to tolerate high levels of sediment and that any transition of coral reefs to more sedimented states may result in a shift to a low diversity sponge dominated system, which is likely to have subsequent effects on ecosystem functioning. PMID:24475041

  4. 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.

  5. The importance of sponges and mangroves in supporting fish communities on degraded coral reefs in Caribbean Panama

    Directory of Open Access Journals (Sweden)

    Janina Seemann

    2018-03-01

    Full Text Available Fish communities associated with coral reefs worldwide are threatened by habitat degradation and overexploitation. We assessed coral reefs, mangrove fringes, and seagrass meadows on the Caribbean coast of Panama to explore the influences of their proximity to one another, habitat cover, and environmental characteristics in sustaining biomass, species richness and trophic structure of fish communities in a degraded tropical ecosystem. We found 94% of all fish across all habitat types were of small body size (≤10 cm, with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes and Gobiidae (gobies. Total fish biomass was very low, with the trend of small fishes from low trophic levels over-represented, and top predators under-represented, relative to coral reefs elsewhere in the Caribbean. For example, herbivorous fishes comprised 27% of total fish biomass in Panama relative to 10% in the wider Caribbean, and the small parrotfish Scarus iseri comprised 72% of the parrotfish biomass. We found evidence that non-coral biogenic habitats support reef-associated fish communities. In particular, the abundance of sponges on a given reef and proximity of mangroves were found to be important positive correlates of reef fish species richness, biomass, abundance and trophic structure. Our study indicates that a diverse fish community can persist on degraded coral reefs, and that the availability and arrangement within the seascape of other habitat-forming organisms, including sponges and mangroves, is critical to the maintenance of functional processes in such ecosystems.

  6. Deep genetic divergences among Indo-Pacific populations of the coral reef sponge Leucetta chagosensis (Leucettidae): founder effects, vicariance, or both?

    Science.gov (United States)

    Wörheide, Gert; Epp, Laura S; Macis, Luciana

    2008-01-26

    An increasing number of studies demonstrate that genetic differentiation and speciation in the sea occur over much smaller spatial scales than previously appreciated given the wide distribution range of many morphologically defined coral reef invertebrate species and the presumed dispersal-enhancing qualities of ocean currents. However, knowledge about the processes that lead to population divergence and speciation is often lacking despite being essential for the understanding, conservation, and management of marine biodiversity. Sponges, a highly diverse, ecologically and economically important reef-invertebrate taxon, exhibit spatial trends in the Indo-West Pacific that are not universally reflected in other marine phyla. So far, however, processes generating those unexpected patterns are not understood. We unraveled the phylogeographic structure of the widespread Indo-Pacific coral reef sponge Leucetta chagosensis across its known geographic range using two nuclear markers: the rDNA internal transcribed spacers (ITS 1&2) and a fragment of the 28S gene, as well as the second intron of the ATP synthetase beta subunit-gene (ATPSb-iII). This enabled the detection of several deeply divergent clades congruent over both loci, one containing specimens from the Indian Ocean (Red Sea and Maldives), another one from the Philippines, and two other large and substructured NW Pacific and SW Pacific clades with an area of overlap in the Great Barrier Reef/Coral Sea. Reciprocally monophyletic populations were observed from the Philippines, Red Sea, Maldives, Japan, Samoa, and Polynesia, demonstrating long-standing isolation. Populations along the South Equatorial Current in the south-western Pacific showed isolation-by-distance effects. Overall, the results pointed towards stepping-stone dispersal with some putative long-distance exchange, consistent with expectations from low dispersal capabilities. We argue that both founder and vicariance events during the late Pliocene and

  7. Deep genetic divergences among Indo-Pacific populations of the coral reef sponge Leucetta chagosensis (Leucettidae: Founder effects, vicariance, or both?

    Directory of Open Access Journals (Sweden)

    Epp Laura S

    2008-01-01

    Full Text Available Abstract Background An increasing number of studies demonstrate that genetic differentiation and speciation in the sea occur over much smaller spatial scales than previously appreciated given the wide distribution range of many morphologically defined coral reef invertebrate species and the presumed dispersal-enhancing qualities of ocean currents. However, knowledge about the processes that lead to population divergence and speciation is often lacking despite being essential for the understanding, conservation, and management of marine biodiversity. Sponges, a highly diverse, ecologically and economically important reef-invertebrate taxon, exhibit spatial trends in the Indo-West Pacific that are not universally reflected in other marine phyla. So far, however, processes generating those unexpected patterns are not understood. Results We unraveled the phylogeographic structure of the widespread Indo-Pacific coral reef sponge Leucetta chagosensis across its known geographic range using two nuclear markers: the rDNA internal transcribed spacers (ITS 1&2 and a fragment of the 28S gene, as well as the second intron of the ATP synthetase beta subunit-gene (ATPSb-iII. This enabled the detection of several deeply divergent clades congruent over both loci, one containing specimens from the Indian Ocean (Red Sea and Maldives, another one from the Philippines, and two other large and substructured NW Pacific and SW Pacific clades with an area of overlap in the Great Barrier Reef/Coral Sea. Reciprocally monophyletic populations were observed from the Philippines, Red Sea, Maldives, Japan, Samoa, and Polynesia, demonstrating long-standing isolation. Populations along the South Equatorial Current in the south-western Pacific showed isolation-by-distance effects. Overall, the results pointed towards stepping-stone dispersal with some putative long-distance exchange, consistent with expectations from low dispersal capabilities. Conclusion We argue that both

  8. High spatial variability of coral, sponges and gorgonian assemblages in a well preserved reef

    Directory of Open Access Journals (Sweden)

    Patricia González-Díaz

    2010-06-01

    Full Text Available The main goal of this research was to obtain baseline field data of the composition of sponges, corals, and gorgonian assemblages that can be used as a reference for future analyses of anthropogenic impact. We tested the hypothesis that relatively homogeneous and well preserved reef units can present notable natural variability in the composition of their communities which are unassociated with changes in land proximity or a human impact gradient. Research was carried out in July 2006 at Los Colorados reef, located in the northwestern region of Pinar del Río Province, Cuba at 12 sampling stations. The biotopes selected were crest, terrace edge and spur and grove. Ecological indicators were diversity of corals, species composition, density of corals, hydrocorals, gorgonians and sponges, and density of selected coral species. A total of 2659 colonies of scleractineans corals representing 36 species were counted. The most abundant species in the crest biotope were Millepora alcicornis, Acropora palmata and Porites astreoides; in the terrace edge and spur and grove, the most abundant species were Siderastrea siderea, Stephanocoenia intersepta, Porites astreoides, Agaricia agaricites and Montastraea cavernosa. We found differences among sites for several indicators (e.g. density of corals, sponges and gorgonians and for selected species, but they could not be associated to any gradient of land influence or human impact. Therefore, sites inside a relatively homogeneous reef unit can present notable natural differences in the composition of their communities. Rev. Biol. Trop. 58 (2: 621-634. Epub 2010 June 02.El objetivo principal de la investigación fue obtener una línea base de la composición de las comunidades de esponjas, corales y gorgonias que pueda ser utilizada como referencia para futuros análisis de impacto antrópico. Nuestra hipótesis es que un arrecife relativamente homogéneo y bien conservado, presenta una variabilidad natural

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

    International Nuclear Information System (INIS)

    Lewis, Stephen E.; Brodie, Jon E.; Bainbridge, Zoe T.; Rohde, Ken W.; Davis, Aaron M.; Masters, Bronwyn L.; Maughan, Mirjam; Devlin, Michelle J.; Mueller, Jochen F.; Schaffelke, Britta

    2009-01-01

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

  10. Genetic assessment of connectivity in the common reef sponge, Callyspongia vaginalis (Demospongiae: Haplosclerida) reveals high population structure along the Florida reef tract

    Science.gov (United States)

    Debiasse, M. B.; Richards, V. P.; Shivji, M. S.

    2010-03-01

    The genetic population structure of the common branching vase sponge, Callyspongia vaginalis, was determined along the entire length (465 km) of the Florida reef system from Palm Beach to the Dry Tortugas based on sequences of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. Populations of C. vaginalis were highly structured (overall ΦST = 0.33), in some cases over distances as small as tens of kilometers. However, nonsignificant pairwise ΦST values were also found between a few relatively distant sampling sites suggesting that some long distance larval dispersal may occur via ocean currents or transport in sponge fragments along continuous, shallow coastlines. Indeed, sufficient gene flow appears to occur along the Florida reef tract to obscure a signal of isolation by distance, but not to homogenize COI haplotype frequencies. The strong genetic differentiation among most of the sampling locations suggests that recruitment in this species is largely local source-driven, pointing to the importance of further elucidating general connectivity patterns along the Florida reef tract to guide the spatial scale of management efforts.

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

    Science.gov (United States)

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

    2012-12-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    KAUST Repository

    Mongin, Mathieu

    2016-02-23

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

  14. [Community structure of sponges (Porifera) in three reefs at Morrocoy National Park, Venezuela and its correspondence with some environmental variables].

    Science.gov (United States)

    Romero, Marco A; Villamizar, Estrella; Malaver, Nora

    2013-09-01

    Sponges have an important ecological role in coral reef ecosystems. However, when compared to other benthic Phyla, it has been little researched. This research was focused in the variability of the community structure of sponges in three locations at Morrocoy National Park (Cayo Sombrero, Playa Mero and Punta Brava) exposed to different environmental conditions (transparency and currents intensity) and affected in different degree of severity by a mass mortality event in 1996. A total of 15 transects (10 m long and 1 m wide) were evaluated in three strata (between 3 and 15 m depth) in each site, where all the individuals were counted by species. Relative abundance by species, diversity and evenness were calculated. Locations showed differences respect turbidity, wave and current intensity. 27 species were found in Morrocoy; Cayo Sombrero (23), Playa Mero (18) and Punta Brava (15). Agelas sceptrum, Amphimedon erina and Niphates erecta were the most common in first location; Niphates erecta and Dysidea etheria in Playa Mero and Dysidea etheria, Niphates erecta and Amphimedon erina in Punta Brava. The species composition showed statistical differences between all three locations; Cayo Sombrero resulted the most diverse and even, followed by Playa Mero and Punta Brava. According to Sorensen Similarity Index results, Cayo Sombrero and Playa Mero were more similar, while Punta Brava resulted the most different. The variability in environmental conditions and the differential mass mortality effects of 1996 in all three reefs, were probably the main causes of the differences between their sponge communities. Nevertheless, we cannot conclude about the weight of these factors.

  15. Temporal and taxonomic contrasts in coral growth at Davies Reef, central Great Barrier Reef, Australia

    Science.gov (United States)

    Anderson, Kristen D.; Cantin, Neal E.; Heron, Scott F.; Lough, Janice M.; Pratchett, Morgan S.

    2018-06-01

    Demographic processes, such as growth, can have an important influence on the population and community structure of reef-building corals. Importantly, ongoing changes in environmental conditions (e.g. ocean warming) are expected to affect coral growth, contributing to changes in the structure of coral populations and communities. This study quantified contemporary growth rates (linear extension and calcification) for the staghorn coral, Acropora muricata, at Davies Reef, central Great Barrier Reef, Australia. Growth rates were measured at three different depths (5, 10, and 15 m) over 2 yr (2012-2014) assessing both seasonal and inter-annual variability. Results of this study were compared to equivalent measurements made in 1980-1982 at the same location. To assist in understanding inter-annual variability in coral growth, we also examined annual growth bands from massive Porites providing continuous growth and records of flooding history for Davies Reef over the period 1979-2012. Linear extension rates of A. muricata were substantially (11-62%) lower in 2012-2014 compared to 1980-1982, especially at 10 and 15 m depths. These declines in growth coincide with a + 0.14 °C change in annual mean temperature. For massive Porites, however, calcification rates were highly variable among years and there was no discernible long-term change in growth despite sustained increases in temperature of 0.064 °C per decade. Apparent differences in the growth rates of Acropora between 1980-1982 and 2012-2014 may reflect inter-annual variation in coral growth (as seen for massive Porites), though it is known branching Acropora is much more sensitive to changing environmental conditions than massive corals. There are persistent issues in assessing the sensitivities of branching corals to environmental change due to limited capacity for retrospective analyses of growth, but given their disproportionate contribution to habitat complexity and reef structure, it is critical to ascertain

  16. Cold-water coral reefs and adjacent sponge grounds: hotspots of benthic respiration and organic carbon cycling in the deep sea

    NARCIS (Netherlands)

    Cathalot, C.; Van Oevelen, D.; Cox, T.; Kutti, T.; Lavaleye, M.S.S.; Duineveld, G.C.A.; Meysman, F.J.R.

    2015-01-01

    Cold-water coral reefs and adjacent sponge grounds are distributed widely in the deep ocean, where only a small fraction of the surface productivity reaches the seafloor as detritus. It remains elusive how these hotspots of biodiversity can thrive in such a food-limited environment, as data on

  17. A review of bottom-up vs. top-down control of sponges on Caribbean fore-reefs: what’s old, what’s new, and future directions

    Directory of Open Access Journals (Sweden)

    Joseph R. Pawlik

    2018-01-01

    Full Text Available Interest in the ecology of sponges on coral reefs has grown in recent years with mounting evidence that sponges are becoming dominant members of reef communities, particularly in the Caribbean. New estimates of water column processing by sponge pumping activities combined with discoveries related to carbon and nutrient cycling have led to novel hypotheses about the role of sponges in reef ecosystem function. Among these developments, a debate has emerged about the relative effects of bottom-up (food availability and top-down (predation control on the community of sponges on Caribbean fore-reefs. In this review, we evaluate the impact of the latest findings on the debate, as well as provide new insights based on older citations. Recent studies that employed different research methods have demonstrated that dissolved organic carbon (DOC and detritus are the principal sources of food for a growing list of sponge species, challenging the idea that the relative availability of living picoplankton is the sole proxy for sponge growth or abundance. New reports have confirmed earlier findings that reef macroalgae release labile DOC available for sponge nutrition. Evidence for top-down control of sponge community structure by fish predation is further supported by gut content studies and historical population estimates of hawksbill turtles, which likely had a much greater impact on relative sponge abundances on Caribbean reefs of the past. Implicit to investigations designed to address the bottom-up vs. top-down debate are appropriate studies of Caribbean fore-reef environments, where benthic communities are relatively homogeneous and terrestrial influences and abiotic effects are minimized. One recent study designed to test both aspects of the debate did so using experiments conducted entirely in shallow lagoonal habitats dominated by mangroves and seagrass beds. The top-down results from this study are reinterpreted as supporting past research

  18. The distribution and abundance of reef-associated predatory fishes on the Great Barrier Reef

    Science.gov (United States)

    Emslie, Michael J.; Cheal, Alistair J.; Logan, Murray

    2017-09-01

    Predatory fishes are important components of coral-reef ecosystems of the Great Barrier Reef (GBR) through both the ecological functions they perform and their high value to recreational and commercial fisheries, estimated at 30 million in 2014. However, management of GBR predatory fish populations is hampered by a lack of knowledge of their distribution and abundance, aside from that of the highly targeted coral trout ( Plectropomus spp. and Variola spp.). Furthermore, there is little information on how these fishes respond to environmental stressors such as coral bleaching, outbreaks of coral-feeding starfishes ( Acanthaster planci) and storms, which limits adaptive management of their populations as the frequency or severity of such natural disturbances increases under climate change. Here, we document the distribution and abundance of 48 species of reef-associated predatory fishes and assess their vulnerability to a range of natural disturbances. There were clear differences in predatory fish assemblages across the continental shelf, but many species were widespread, with few species restricted to either inshore or offshore waters. There was weak latitudinal structure with only a few species restricted to either the northern or southern GBR. On the whole, predatory fishes were surprisingly resistant to the effects of disturbance, with few clear changes in abundance or species richness following 66 documented disturbances of varying magnitudes.

  19. Soft coral abundance on the central Great Barrier Reef: effects of Acanthaster planci, space availability, and aspects of the physical environment

    Science.gov (United States)

    Fabricius, K. E.

    1997-07-01

    The distribution and abundance of soft coral genera on reefs of the central Great Barrier Reef was investigated in relation to reef position, recent history of disturbance, wave exposure, substratum slope and depth. Eighty-five 25 m long transects were surveyed at 10 m depth on windward sides of 14 mid- and outer-shelf reefs. A further 75 transects in different zones on one mid-shelf reef (Davies Reef) between 5 and 30 m depth were investigated. The crown-of-thorns starfish Acanthaster planci had caused large-scale mortality of scleractinians on eight of these reefs five to ten years prior to the study, and as a result, scleractinian cover was only 35-55% of that on the six unimpacted reefs. On the impacted reefs, stony corals with massive and encrusting growths form had smaller average colony diameters but similar or slightly lower numerical abundance. In contrast, mean colony size, cover and abundance of branching stony corals showed no difference between impacted and unimpacted reefs. Twenty-four genera of soft corals (in eight families) were recorded, and none showed different abundance or cover in areas of former A. planci impact, compared to unaffected sites. Similarly, no difference was detected among locations in the numbers or area cover of sponges, tunicates, zoanthids, Halimeda or other macro-algae. Mean soft coral cover was 2 to 5% at 10 m on sheltered mid-shelf reefs, and 12 to 17% on more current-exposed reefs. Highest cover and abundances generally occurred on platforms of outer-shelf reefs exposed to relatively strong currents but low wave energy. On Davies Reef, cover and colony numbers of the families Nephtheidae and Xeniidae were low within the zone of wave impact, in flow-protected bays and lagoons, on shaded steep slopes, and at depths above 10 and below 25 m. In contrast, distributions of genera of the family Alcyoniidae were not related to these physical parameters. The physical conditions of a large proportion of habitats appear "sub

  20. Cold-water coral reefs and adjacent sponge grounds: Hotspots of benthic respiration and organic carbon cycling in the deep sea

    Directory of Open Access Journals (Sweden)

    Cecile eCathalot

    2015-06-01

    Full Text Available Cold-water coral reefs and adjacent sponge grounds are distributed widely in the deep ocean, where only a small fraction of the surface productivity reaches the seafloor as detritus. It remains elusive how these hotspots of biodiversity can thrive in such a food-limited environment, as data on energy flow and organic carbon utilization are critically lacking. Here we report in situ community respiration rates for cold-water coral and sponge ecosystems obtained by the non-invasive aquatic Eddy Correlation technique. Oxygen uptake rates over coral reefs and adjacent sponge grounds in the Træna Coral Field (Norway were 9-20 times higher than those of the surrounding soft sediments. These high respiration rates indicate strong organic matter consumption, and hence suggest a local focusing onto these ecosystems of the downward flux of organic matter that is exported from the surface ocean. Overall, our results show that coral reefs and adjacent sponge grounds are hotspots of carbon processing in the food-limited deep ocean, and that these deep-sea ecosystems play a more prominent role in marine biogeochemical cycles than previously recognized.

  1. Surviving in a marine desert: The sponge loop retains resources within coral reefs

    NARCIS (Netherlands)

    de Goeij, J.M.; van Oevelen, D.; Vermeij, M.J.A.; Osinga , R.; Middelburg, J.J.; de Goeij, A.F.P.M.; Admiraal, W.

    2013-01-01

    Ever since Darwin’s early descriptions of coral reefs, scientists have debated how one of the world’s most productive and diverse ecosystems can thrive in the marine equivalent of a desert. It is an enigma how the flux of dissolved organic matter (DOM), the largest resource produced on reefs, is

  2. Surviving in a marine desert: the sponge loop retains resources within coral reefs

    NARCIS (Netherlands)

    de Goei, J.M.; van Oevelen, D.; Vermeij, M.J.A.; Osinga, R.; Middelburg, J.J.; de Goei, A.F.P.M.; Admiraal, W.

    2013-01-01

    Ever since Darwin’s early descriptions of coral reefs, scientists have debated how one of the world’s most productive and diverse ecosystems can thrive in the marine equivalent of a desert. It is an enigma how the flux of dissolved organic matter (DOM), the largest resource produced on reefs, is

  3. Surviving in a Marine Desert: The Sponge Loop Retains Resources Within Coral Reefs

    NARCIS (Netherlands)

    de Goeij, J.M.; van Oevelen, D.; Vermeij, M.J.A.; Osinga, R.; Middelburg, J.J.; de Goeij, A.F.P.M.; Admiraal, W.

    2013-01-01

    Ever since Darwin’s early descriptions of coral reefs, scientists have debated how one of the world’s most productive and diverse ecosystems can thrive in the marine equivalent of a desert. It is an enigma how the flux of dissolved organic matter (DOM), the largest resource produced on reefs, is

  4. Prey Density Threshold and Tidal Influence on Reef Manta Ray Foraging at an Aggregation Site on the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Asia O Armstrong

    Full Text Available Large tropical and sub-tropical marine animals must meet their energetic requirements in a largely oligotrophic environment. Many planktivorous elasmobranchs, whose thermal ecologies prevent foraging in nutrient-rich polar waters, aggregate seasonally at predictable locations throughout tropical oceans where they are observed feeding. Here we investigate the foraging and oceanographic environment around Lady Elliot Island, a known aggregation site for reef manta rays Manta alfredi in the southern Great Barrier Reef. The foraging behaviour of reef manta rays was analysed in relation to zooplankton populations and local oceanography, and compared to long-term sighting records of reef manta rays from the dive operator on the island. Reef manta rays fed at Lady Elliot Island when zooplankton biomass and abundance were significantly higher than other times. The critical prey density threshold that triggered feeding was 11.2 mg m-3 while zooplankton size had no significant effect on feeding. The community composition and size structure of the zooplankton was similar when reef manta rays were feeding or not, with only the density of zooplankton changing. Higher zooplankton biomass was observed prior to low tide, and long-term (~5 years sighting data confirmed that more reef manta rays are also observed feeding during this tidal phase than other times. This is the first study to examine prey availability at an aggregation site for reef manta rays and it indicates that they feed in locations and at times of higher zooplankton biomass.

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

    NARCIS (Netherlands)

    Kragt, M.E.; Roebeling, P.C.; Ruijs, A.J.W.

    2009-01-01

    There is a growing concern that increased nutrient and sediment runoff from river catchments are a potential source of coral reef degradation. Degradation of reefs may affect the number of tourists visiting the reef and, consequently, the economic sectors that rely on healthy reefs for their income

  6. Bacterial community composition and predicted functional ecology of sponges, sediment and seawater from the thousand islands reef complex, West Java, Indonesia.

    Science.gov (United States)

    de Voogd, Nicole J; Cleary, Daniel F R; Polónia, Ana R M; Gomes, Newton C M

    2015-04-01

    In the present study, we assessed the composition of Bacteria in four biotopes namely sediment, seawater and two sponge species (Stylissa massa and Xestospongia testudinaria) at four different reef sites in a coral reef ecosystem in West Java, Indonesia. In addition to this, we used a predictive metagenomic approach to estimate to what extent nitrogen metabolic pathways differed among bacterial communities from different biotopes. We observed marked differences in bacterial composition of the most abundant bacterial phyla, classes and orders among sponge species, water and sediment. Proteobacteria were by far the most abundant phylum in terms of both sequences and Operational Taxonomic Units (OTUs). Predicted counts for genes associated with the nitrogen metabolism suggested that several genes involved in the nitrogen cycle were enriched in sponge samples, including nosZ, nifD, nirK, norB and nrfA genes. Our data show that a combined barcoded pyrosequencing and predictive metagenomic approach can provide novel insights into the potential ecological functions of the microbial communities. Not only is this approach useful for our understanding of the vast microbial diversity found in sponges but also to understand the potential response of microbial communities to environmental change. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. The Great Barrier Reef:The chronological record from a new borehole

    NARCIS (Netherlands)

    Braithwaite, C.J.; Dalmasso, H.; Gilmour, M.A.; Harkness, D.D.; Henderson, G.M.; Kay, R.L.F.; Kroon, D.; Montaggioni, L.F.; Wilson, P.A.

    2004-01-01

    A new borehole, 210 mbsf (meters below sea floor) deep, drilled in Ribbon Reef 5 on the Great Barrier Reef off Cooktown, NE Australia, reveals a shallowing-upwards succession, the younger part of which is punctuated by a series of erosion surfaces. Nine depositional units have been defined by

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

    International Nuclear Information System (INIS)

    Suzuki, Atsushi; Kawahata, Hodaka

    2003-01-01

    The seawater CO 2 system and carbon budget were examined in coral reefs of wide variety with respect to topographic types and oceanographic settings in the Indo-Pacific oceans. A system-level net organic-to-inorganic carbon production ratio (ROI) is a master parameter for controlling the carbon cycle in coral reef systems, including their sink/source behavior for atmospheric CO 2 . A reef system with ROI less than approximately 0.6 has a potential for releasing CO 2 . The production ratio, however, is not easy to estimate on a particular reef. Instead, observations planned to detect the offshore-lagoon difference in partial pressure of CO 2 (pCO 2 ) and a graphic approach based on a total alkalinity-dissolved inorganic carbon diagram can reveal system-level performance of the carbon cycle in coral reefs. Surface pCO 2 values in the lagoons of atolls and barrier reefs were consistently higher than those in their offshore waters, showing differences between 6 and 46 atm, together with a depletion in total alkalinity up to 100 mol/kg, indicating predominant carbonate production relative to net organic carbon production. Reef topography, especially residence time of lagoon water, has a secondary effect on the magnitude of the offshore-lagoon pCO 2 difference. Terrestrial influence was recognized in coastal reefs, including the GBR lagoon and a fringing reef of the Ryukyu Islands. High carbon input appears to enhance CO 2 efflux to the atmosphere because of their high dissolved C:P ratios. Coral reefs, in general, act as an alkalinity sink and a potentially CO 2 -releasing site due to carbonate precipitation and land-derived carbon

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

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsushi; Kawahata, Hodaka [National Inst. of Advanced Industrial Science and Technology, Ibaraki (Japan). Inst. for Marine Resources and Environment

    2003-04-01

    The seawater CO{sub 2} system and carbon budget were examined in coral reefs of wide variety with respect to topographic types and oceanographic settings in the Indo-Pacific oceans. A system-level net organic-to-inorganic carbon production ratio (ROI) is a master parameter for controlling the carbon cycle in coral reef systems, including their sink/source behavior for atmospheric CO{sub 2}. A reef system with ROI less than approximately 0.6 has a potential for releasing CO{sub 2}. The production ratio, however, is not easy to estimate on a particular reef. Instead, observations planned to detect the offshore-lagoon difference in partial pressure of CO{sub 2} (pCO{sub 2}) and a graphic approach based on a total alkalinity-dissolved inorganic carbon diagram can reveal system-level performance of the carbon cycle in coral reefs. Surface pCO{sub 2} values in the lagoons of atolls and barrier reefs were consistently higher than those in their offshore waters, showing differences between 6 and 46 atm, together with a depletion in total alkalinity up to 100 mol/kg, indicating predominant carbonate production relative to net organic carbon production. Reef topography, especially residence time of lagoon water, has a secondary effect on the magnitude of the offshore-lagoon pCO{sub 2} difference. Terrestrial influence was recognized in coastal reefs, including the GBR lagoon and a fringing reef of the Ryukyu Islands. High carbon input appears to enhance CO{sub 2} efflux to the atmosphere because of their high dissolved C:P ratios. Coral reefs, in general, act as an alkalinity sink and a potentially CO{sub 2}-releasing site due to carbonate precipitation and land-derived carbon.

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

    Science.gov (United States)

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

    2014-12-01

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

  11. Sponge-associated bacteria of Lakshadweep coral reefs, India: resource for extracellular hydrolytic enzymes

    Digital Repository Service at National Institute of Oceanography (India)

    Feby, A.; Nair, S.

    to Whirlpak sterile sampling bags (Nasco) and sealed underwater to prevent contact with air and possible oxidation and contamination. Ambient seawater was collected using 1.8L Niskin water sampler within 1m of the sponge colony and transferred to Whirlpak... reaction. 2.3.8. API ZYM Micro Method Selected candidate isolates with promising enzymatic activity were semi quantitatively determined with API ZYM (API bioMerieux Ltd) micro method [11]. The procedure was as per the manufactures instruction...

  12. Invasive lionfish had no measurable effect on prey fish community structure across the Belizean Barrier Reef.

    Science.gov (United States)

    Hackerott, Serena; Valdivia, Abel; Cox, Courtney E; Silbiger, Nyssa J; Bruno, John F

    2017-01-01

    Invasive lionfish are assumed to significantly affect Caribbean reef fish communities. However, evidence of lionfish effects on native reef fishes is based on uncontrolled observational studies or small-scale, unrepresentative experiments, with findings ranging from no effect to large effects on prey density and richness. Moreover, whether lionfish affect populations and communities of native reef fishes at larger, management-relevant scales is unknown. The purpose of this study was to assess the effects of lionfish on coral reef prey fish communities in a natural complex reef system. We quantified lionfish and the density, richness, and composition of native prey fishes (0-10 cm total length) at sixteen reefs along ∼250 km of the Belize Barrier Reef from 2009 to 2013. Lionfish invaded our study sites during this four-year longitudinal study, thus our sampling included fish community structure before and after our sites were invaded, i.e., we employed a modified BACI design. We found no evidence that lionfish measurably affected the density, richness, or composition of prey fishes. It is possible that higher lionfish densities are necessary to detect an effect of lionfish on prey populations at this relatively large spatial scale. Alternatively, negative effects of lionfish on prey could be small, essentially undetectable, and ecologically insignificant at our study sites. Other factors that influence the dynamics of reef fish populations including reef complexity, resource availability, recruitment, predation, and fishing could swamp any effects of lionfish on prey populations.

  13. Invasive lionfish had no measurable effect on prey fish community structure across the Belizean Barrier Reef

    Directory of Open Access Journals (Sweden)

    Serena Hackerott

    2017-05-01

    Full Text Available Invasive lionfish are assumed to significantly affect Caribbean reef fish communities. However, evidence of lionfish effects on native reef fishes is based on uncontrolled observational studies or small-scale, unrepresentative experiments, with findings ranging from no effect to large effects on prey density and richness. Moreover, whether lionfish affect populations and communities of native reef fishes at larger, management-relevant scales is unknown. The purpose of this study was to assess the effects of lionfish on coral reef prey fish communities in a natural complex reef system. We quantified lionfish and the density, richness, and composition of native prey fishes (0–10 cm total length at sixteen reefs along ∼250 km of the Belize Barrier Reef from 2009 to 2013. Lionfish invaded our study sites during this four-year longitudinal study, thus our sampling included fish community structure before and after our sites were invaded, i.e., we employed a modified BACI design. We found no evidence that lionfish measurably affected the density, richness, or composition of prey fishes. It is possible that higher lionfish densities are necessary to detect an effect of lionfish on prey populations at this relatively large spatial scale. Alternatively, negative effects of lionfish on prey could be small, essentially undetectable, and ecologically insignificant at our study sites. Other factors that influence the dynamics of reef fish populations including reef complexity, resource availability, recruitment, predation, and fishing could swamp any effects of lionfish on prey populations.

  14. Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

    KAUST Repository

    Williamson, David H.

    2016-11-15

    Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

  15. Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

    KAUST Repository

    Williamson, David H.; Harrison, Hugo B.; Almany, Glenn R.; Berumen, Michael L.; Bode, Michael; Bonin, Mary C.; Choukroun, Severine; Doherty, Peter J.; Frisch, Ashley J.; Saenz-Agudelo, Pablo; Jones, Geoffrey P.

    2016-01-01

    Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

  16. Geomorphology and sediment transport on a submerged back-reef sand apron: One Tree Reef, Great Barrier Reef

    Science.gov (United States)

    Harris, Daniel L.; Vila-Concejo, Ana; Webster, Jody M.

    2014-10-01

    Back-reef sand aprons are conspicuous and dynamic sedimentary features in coral reef systems. The development of these features influences the evolution and defines the maturity of coral reefs. However, the hydrodynamic processes that drive changes on sand aprons are poorly understood with only a few studies directly assessing sediment entrainment and transport. Current and wave conditions on a back-reef sand apron were measured during this study and a digital elevation model was developed through topographic and bathymetric surveying of the sand apron, reef flats and lagoon. The current and wave processes that may entrain and transport sediment were assessed using second order small amplitude (Stokes) wave theory and Shields equations. The morphodynamic interactions between current flow and geomorphology were also examined. The results showed that sediment transport occurs under modal hydrodynamic conditions with waves the main force entraining sediment rather than average currents. A morphodynamic relationship between current flow and geomorphology was also observed with current flow primarily towards the lagoon in shallow areas of the sand apron and deeper channel-like areas directing current off the sand apron towards the lagoon or the reef crest. These results show that the short-term mutual interaction of hydrodynamics and geomorphology in coral reefs can result in morphodynamic equilibrium.

  17. Differential responses of emergent intertidal coral reef fauna to a large-scale El-Niño southern oscillation event: sponge and coral resilience.

    Science.gov (United States)

    Kelmo, Francisco; Bell, James J; Moraes, Simone Souza; Gomes, Rilza da Costa Tourinho; Mariano-Neto, Eduardo; Attrill, Martin J

    2014-01-01

    There is a paucity of information on the impacts of the 1997-8 El Niño event and subsequent climatic episodes on emergent intertidal coral reef assemblages. Given the environmental variability intertidal reefs experience, such reefs may potentially be more resilient to climatic events and provide important insights into the adaptation of reef fauna to future ocean warming. Here we report the results of a 17-year (1995-2011) biodiversity survey of four emergent coral reef ecosystems in Bahia, Brazil, to assess the impact of a major El Niño event on the reef fauna, and determine any subsequent recovery. The densities of two species of coral, Favia gravida and Siderastrea stellata, did not vary significantly across the survey period, indicating a high degree of tolerance to the El Niño associated stress. However, there were marked decreases in the diversity of other taxa. Molluscs, bryozoans and ascidians suffered severe declines in diversity and abundance and had not recovered to pre-El Niño levels by the end of the study. Echinoderms were reduced to a single species in 1999, Echinometra lucunter, although diversity levels had recovered by 2002. Sponge assemblages were not impacted by the 1997-8 event and their densities had increased by the study end. Multivariate analysis indicated that a stable invertebrate community had re-established on the reefs after the El Niño event, but it has a different overall composition to the pre-El Niño community. It is unclear if community recovery will continue given more time, but our study highlights that any increase in the frequency of large-scale climatic events to more than one a decade is likely to result in a persistent lower-diversity state. Our results also suggest some coral and sponge species are particularly resilient to the El Niño-associated stress and therefore represent suitable models to investigate temperature adaptation in reef organisms.

  18. Large-scale bleaching of corals on the Great Barrier Reef.

    Science.gov (United States)

    Hughes, T P; Kerry, J T; Simpson, T

    2018-02-01

    In 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching. In the southern hemisphere summer of March-April 2016, we used aerial surveys to measure the level of bleaching on 1,156 individual reefs throughout the 2,300 km length of the Great Barrier Reef, the world's largest coral reef system. The accuracy of the aerial scores was ground-truthed with detailed underwater surveys of bleaching at 260 sites (104 reefs), allowing us to compare aerial and underwater bleaching data with satellite-derived temperatures and with associated model predictions of bleaching. The severity of bleaching on individual reefs in 2016 was tightly correlated with the level of local heat exposure: the southernmost region of the Great Barrier Reef escaped with only minor bleaching because summer temperatures there were close to average. Gradients in nutrients and turbidity from inshore to offshore across the Great Barrier Reef had minimal effect on the severity of bleaching. Similarly, bleaching was equally severe on reefs that are open or closed to fishing, once the level of satellite-derived heat exposure was accounted for. The level of post-bleaching mortality, measured underwater after 7-8 months, was tightly correlated with the aerial scores measured at the peak of bleaching. Similarly, reefs with a high aerial bleaching score also experienced major shifts in species composition due to extensive mortality of heat-sensitive species. Reefs with low bleaching scores did not change in composition, and some showed minor increases in coral cover. Two earlier mass bleaching events occurred on the Great Barrier Reef in 1998 and 2002, that were less severe than 2016. In 2016, bleaching, compared to 42% in 2002 and 44% in 1998. Conversely, the proportion of reefs that were severely bleached (>60% of corals affected) was four times higher in 2016. The geographic footprint of each of the three events is distinctive, and matches satellite-derived sea surface

  19. Main features of the geological structure of upper-Frasnian barrier reefs in relation to their petroleum content

    Energy Technology Data Exchange (ETDEWEB)

    Nikonov, N.I.

    1981-01-01

    Analysis of new geological geophysical and industrial materials has made it possible to distinguish in the boundary part of the late Devonician shoal carbonate shelf barrier reefs of various ages. In confines of individual distinguished reefs there have been established deposits of oil (Western Tebuksk, Pashsor and Khar'yatinsk). There are given prospecting features of classification of buried reefs and prognoses for the finding possible oil deposits in them (Beyaksk, Sandiveis reefs).

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

    Science.gov (United States)

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

    2010-03-01

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

  1. Seismic evidence of glacial-age river incision into the Tahaa barrier reef, French Polynesia

    Science.gov (United States)

    Toomey, Michael; Woodruff, Jonathan D.; Ashton, Andrew D.; Perron, J. Taylor

    2016-01-01

    Rivers have long been recognized for their ability to shape reef-bound volcanic islands. On the time-scale of glacial–interglacial sea-level cycles, fluvial incision of exposed barrier reef lagoons may compete with constructional coral growth to shape the coastal geomorphology of ocean islands. However, overprinting of Pleistocene landscapes by Holocene erosion or sedimentation has largely obscured the role lowstand river incision may have played in developing the deep lagoons typical of modern barrier reefs. Here we use high-resolution seismic imagery and core stratigraphy to examine how erosion and/or deposition by upland drainage networks has shaped coastal morphology on Tahaa, a barrier reef-bound island located along the Society Islands hotspot chain in French Polynesia. At Tahaa, we find that many channels, incised into the lagoon floor during Pleistocene sea-level lowstands, are located near the mouths of upstream terrestrial drainages. Steeper antecedent topography appears to have enhanced lowstand fluvial erosion along Tahaa's southwestern coast and maintained a deep pass. During highstands, upland drainages appear to contribute little sediment to refilling accommodation space in the lagoon. Rather, the flushing of fine carbonate sediment out of incised fluvial channels by storms and currents appears to have limited lagoonal infilling and further reinforced development of deep barrier reef lagoons during periods of highstand submersion.

  2. Elevated land runoff after European settlement perturbs persistent foraminiferal assemblages on the Great Barrier Reef.

    Science.gov (United States)

    Uthicke, S; Patel, F; Ditchburn, R

    2012-01-01

    Coral reefs are under pressure from a variety of human-induced disturbances, but demonstration of ecosystem changes and identification of stressors are often difficult. We tested whether global change or increased agricultural runoff after European settlement of Northeast Australia (ca. 1860) has affected inshore reefs of the Great Barrier Reef. Eleven sediment cores were retrieved from inner reefs, intermediate reefs, and outer-island reefs, and benthic foraminiferal assemblages were analyzed in dated (14C, 210Pb, 137Cs) core sections (N = 82 samples). Data were grouped into six age bands ( 1500 yr). Principal component analysis and two-factor (Zone and Age) permutational analysis of variance (PERMANOVA) suggested that assemblages from the three zones were significantly different from each other over several millennia, with symbiont-bearing (mixotrophic) species dominating the outer reefs. A significant interaction term indicated that within-zone patterns varied. Assemblages in outer reefs unaffected from increased land runoff were persistent until present times. In both other zones, assemblages were also persistent until 150 yr ago, suggesting that benthic foraminiferal assemblages are naturally highly persistent over long (> 2000 yr) timescales. Assemblages in core sections PERMANOVA. With some exceptions, changes on the inner and intermediate reefs were consistent with a model predicting that increased nutrients and higher turbidity enhance relative abundance of heterotrophic species. Given that assemblages did not change in outer-island reefs (not impacted by runoff) we argue that changes in assemblages due to global change can be rejected as an explanation. Thus, the findings are more consistent with the hypothesis that agricultural runoff since European settlement altered foraminiferal assemblages than with the hypothesis that global forcing caused changes.

  3. Antifoulant (butyltin and copper) concentrations in sediments from the Great Barrier Reef World Heritage Area, Australia

    International Nuclear Information System (INIS)

    Haynes, David; Loong, Dominica

    2002-01-01

    Antifoulant concentrations are generally low in the Great Barrier Reef, although ship grounding sites present a previously unidentified significant source of antifoulant pollutants in the Great Barrier Reef. - Antifoulant concentrations were determined in marine sediments collected from commercial harbours, marinas, mooring locations on mid-shelf continental islands, and outer reef sites in four regions within the Great Barrier Reef World Heritage Area in 1999. Highest copper concentrations were present in sediments collected from commercial harbour sampling sites (28-233 μg Cu g -1 dry wt.). In contrast, copper concentrations in sediments collected from boat mooring sites on mid-shelf continental islands and outer reef sites were at background concentrations (i.e. -1 dry wt.). Butyltin was only detectable in four of the 42 sediments sampled for analysis, and was only present in sediments collected from commercial harbours (18-1275 ng Sn g -1 dry wt.) and from marinas (4-5 ng Sn g -1 dry wt.). The detection of tributyltin at marina sites implies that this antifoulant may continue to be used illegally on the hulls of smaller recreational vessels. Sediment samples were also collected opportunistically from the site of a 22,000 t cargo ship grounding in May 1999 at Heath Reef, in the far northern Great Barrier Reef. Butyltin concentrations were grossly elevated (660-340,000 ng Sn g -1 dry wt.) at the grounding site. The impact of residual antifoulants at large ship grounding sites should be recognised as a significant, long-term environmental problem unless antfoulant clean-up strategies are undertaken

  4. Coral reefs of the turbid inner-shelf of the Great Barrier Reef, Australia: An environmental and geomorphic perspective on their occurrence, composition and growth

    Science.gov (United States)

    Browne, N. K.; Smithers, S. G.; Perry, C. T.

    2012-10-01

    Investigations of the geomorphic and sedimentary context in which turbid zone reefs exist, both in the modern and fossil reef record, can inform key ecological debates regarding species tolerances and adaptability to elevated turbidity and sedimentation. Furthermore, these investigations can address critical geological and palaeoecological questions surrounding longer-term coral-sediment interactions and reef growth histories. Here we review current knowledge about turbid zone reefs from the inner-shelf regions of the Great Barrier Reef (GBR) in Australia to consider these issues and to evaluate reef growth in the period prior to and post European settlement. We also consider the future prospects of these reefs under reported changing water quality regimes. Turbid zone reefs on the GBR are relatively well known compared to those in other reef regions. They occur within 20 km of the mainland coast where reef development may be influenced by continual or episodic terrigenous sediment inputs, fluctuating salinities (24-36 ppt), and reduced water quality through increased nutrient and pollutant delivery from urban and agricultural runoff. Individually, and in synergy, these environmental conditions are widely viewed as unfavourable for sustained and vigorous coral reef growth, and thus these reefs are widely perceived as marginal compared to clear water reef systems. However, recent research has revealed that this view is misleading, and that in fact many turbid zone reefs in this region are resilient, exhibit relatively high live coral cover (> 30%) and have distinctive community assemblages dominated by fast growing (Acropora, Montipora) and/or sediment tolerant species (Turbinaria, Goniopora, Galaxea, Porites). Palaeoecological reconstructions based on the analysis of reef cores show that community assemblages are relatively stable at millennial timescales, and that many reefs are actively accreting (average 2-7 mm/year) where accommodation space is available

  5. Coral skeletons provide historical evidence of phosphorus runoff on the great barrier reef.

    Directory of Open Access Journals (Sweden)

    Jennie Mallela

    Full Text Available Recently, the inshore reefs of the Great Barrier Reef have declined rapidly because of deteriorating water quality. Increased catchment runoff is one potential culprit. The impacts of land-use on coral growth and reef health however are largely circumstantial due to limited long-term data on water quality and reef health. Here we use a 60 year coral core record to show that phosphorus contained in the skeletons (P/Ca of long-lived, near-shore Porites corals on the Great Barrier Reef correlates with annual records of fertiliser application and particulate phosphorus loads in the adjacent catchment. Skeletal P/Ca also correlates with Ba/Ca, a proxy for fluvial sediment loading, again linking near-shore phosphorus records with river runoff. Coral core records suggest that phosphorus levels increased 8 fold between 1949 and 2008 with the greatest levels coinciding with periods of high fertiliser-phosphorus use. Periods of high P/Ca correspond with intense agricultural activity and increased fertiliser application in the river catchment following agricultural expansion and replanting after cyclone damage. Our results demonstrate how coral P/Ca records can be used to assess terrestrial nutrient loading of vulnerable near-shore reefs.

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

    Science.gov (United States)

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

    2013-09-01

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

  7. The evolution of the Great Barrier Reef during the Last Interglacial Period

    Science.gov (United States)

    Dechnik, Belinda; Webster, Jody M.; Webb, Gregory E.; Nothdurft, Luke; Dutton, Andrea; Braga, Juan-Carlos; Zhao, Jian-xin; Duce, Stephanie; Sadler, James

    2017-02-01

    Reef response to Last Interglacial (LIG) sea level and palaeoenvironmental change has been well documented at a limited number of far-field sites remote from former ice sheets. However, the age and development of LIG reefs in the Great Barrier Reef (GBR) remain poorly understood due to their location beneath modern living reefs. Here we report thirty-nine new mass spectrometry U-Th ages from seven LIG platform reefs across the northern, central and southern GBR. Two distinct geochemical populations of corals were observed, displaying activity ratios consistent with either closed or open system evolution. Our closed-system ages ( 129-126 ka) provide the first reliable LIG ages for the entire GBR. Combined with our open-system model ages, we are able to constrain the interval of significant LIG reef growth in the southern GBR to between 129-121 ka. Using age-elevation data in conjunction with newly defined coralgal assemblages and sedimentary facies analysis we have defined three distinct phases of LIG reef development in response to major sea level and oceanographic changes. These phases include: Phase 1 (> 129 ka), a shallow-water coralgal colonisation phase following initial flooding of the older, likely Marine Isotope Stage 7 (MIS7) antecedent platform; Phase 2 ( 129 ka), a near drowning event in response to rapid sea level rise and greater nutrient-rich upwelling and; Phase 3 ( 128-121 ka), establishment of significant reef framework through catch-up reef growth, initially characterised by deeper, more turbid coralgal assemblages (Phase 3a) that transition to shallow-water assemblages following sea level stabilisation (Phase 3b). Coralgal assemblage analysis indicates that the palaeoenvironments during initial reef growth phases (1 and 2) of the LIG were significantly different than the initial reef growth phases in the Holocene. However, the similar composition of ultimate shallow-water coralgal assemblages and slow reef accretion rates following stabilisation

  8. In four shallow and mesophotic tropical reef sponges from Guam the microbial community largely depends on host identity

    NARCIS (Netherlands)

    Steinert, Georg; Taylor, Michael W.; Deines, Peter; Simister, Rachel L.; Voogd, De Nicole J.; Hoggard, Michael; Schupp, Peter J.

    2016-01-01

    Sponges (phylum Porifera) are important members of almost all aquatic ecosystems, and are renowned for hosting often dense and diverse microbial communities. While the specificity of the sponge microbiota seems to be closely related to host phylogeny, the environmental factors that could shape

  9. Deposition of organic material in a coral reef lagoon, One Tree Island, Great Barrier Reef

    Science.gov (United States)

    Koop, K.; Larkum, A. W. D.

    1987-07-01

    Deposition of organic material was measured at four sites on One Tree Island coral reef using fixed sediment traps. Although no reliable data were obtained for the reef crest area because of problems of resuspension, mean deposition in the backreef area amounted to some 4 g organic C m -2 day -1 whereas in the lagoon it was about 1·5 g C m -2 day -1. This amounted to mean nitrogen deposition rates of 160 and 95 mg N m -2 day -1, respectively. As primary production by turf algae, the principal producers at One Tree Island, has been estimated at about 2·3 g C m -2 day -1 for the whole reef system and the weighted mean carbon deposition is estimated at 2·2 g C m -2 day -1, it is clear that the carbon produced by plants is largely retained in the system. Nitrogen deposition, on the other hand, amounted to only about 60% of that produced by turf algae and it must be assumed that much of this leached into the water during sedimentation. Losses of nitrogen may be minimized by incorporation of dissolved nitrogen by pelagic microheterotrophs which may in turn be consumed by filter feeders before they leave the reef.

  10. Climate change and environmentally responsible behavior on the Great Barrier Reef, Australia

    Science.gov (United States)

    Jee In Yoon; Gerard Kyle; Carena J. vanRiper; Stephen G. Sutton

    2012-01-01

    This study explored the relationship between Australians' perceptions of climate change, its impact on the Great Barrier Reef (GBR), and predictors of environmentally responsible behavior (ERB). Our hypothesized model suggested that general attitudes toward climate change, social pressure for engaging in ERBs (subjective norms), and perceived behavioral control (...

  11. Ocean acidification: Linking science to management solutions using the Great Barrier Reef as a case study.

    Science.gov (United States)

    Albright, Rebecca; Anthony, Kenneth R N; Baird, Mark; Beeden, Roger; Byrne, Maria; Collier, Catherine; Dove, Sophie; Fabricius, Katharina; Hoegh-Guldberg, Ove; Kelly, Ryan P; Lough, Janice; Mongin, Mathieu; Munday, Philip L; Pears, Rachel J; Russell, Bayden D; Tilbrook, Bronte; Abal, Eva

    2016-11-01

    Coral reefs are one of the most vulnerable ecosystems to ocean acidification. While our understanding of the potential impacts of ocean acidification on coral reef ecosystems is growing, gaps remain that limit our ability to translate scientific knowledge into management action. To guide solution-based research, we review the current knowledge of ocean acidification impacts on coral reefs alongside management needs and priorities. We use the world's largest continuous reef system, Australia's Great Barrier Reef (GBR), as a case study. We integrate scientific knowledge gained from a variety of approaches (e.g., laboratory studies, field observations, and ecosystem modelling) and scales (e.g., cell, organism, ecosystem) that underpin a systems-level understanding of how ocean acidification is likely to impact the GBR and associated goods and services. We then discuss local and regional management options that may be effective to help mitigate the effects of ocean acidification on the GBR, with likely application to other coral reef systems. We develop a research framework for linking solution-based ocean acidification research to practical management options. The framework assists in identifying effective and cost-efficient options for supporting ecosystem resilience. The framework enables on-the-ground OA management to be the focus, while not losing sight of CO2 mitigation as the ultimate solution. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  13. Exploring individual- to population-level impacts of disease on coral reef sponges: using spatial analysis to assess the fate, dynamics, and transmission of Aplysina Red Band Syndrome (ARBS.

    Directory of Open Access Journals (Sweden)

    Cole G Easson

    Full Text Available Marine diseases are of increasing concern for coral reef ecosystems, but often their causes, dynamics and impacts are unknown. The current study investigated the epidemiology of Aplysina Red Band Syndrome (ARBS, a disease affecting the Caribbean sponge Aplysina cauliformis, at both the individual and population levels. The fates of marked healthy and ARBS-infected sponges were examined over the course of a year. Population-level impacts and transmission mechanisms of ARBS were investigated by monitoring two populations of A. cauliformis over a three year period using digital photography and diver-collected data, and analyzing these data with GIS techniques of spatial analysis. In this study, three commonly used spatial statistics (Ripley's K, Getis-Ord General G, and Moran's Index were compared to each other and with direct measurements of individual interactions using join-counts, to determine the ideal method for investigating disease dynamics and transmission mechanisms in this system. During the study period, Hurricane Irene directly impacted these populations, providing an opportunity to assess potential storm effects on A. cauliformis and ARBS.Infection with ARBS caused increased loss of healthy sponge tissue over time and a higher likelihood of individual mortality. Hurricane Irene had a dramatic effect on A. cauliformis populations by greatly reducing sponge biomass on the reef, especially among diseased individuals. Spatial analysis showed that direct contact between A. cauliformis individuals was the likely transmission mechanism for ARBS within a population, evidenced by a significantly higher number of contact-joins between diseased sponges compared to random. Of the spatial statistics compared, the Moran's Index best represented true connections between diseased sponges in the survey area. This study showed that spatial analysis can be a powerful tool for investigating disease dynamics and transmission in a coral reef ecosystem.

  14. Integrating observational and modelling systems for the management of the Great Barrier Reef

    Science.gov (United States)

    Baird, M. E.; Jones, E. M.; Margvelashvili, N.; Mongin, M.; Rizwi, F.; Robson, B.; Schroeder, T.; Skerratt, J.; Steven, A. D.; Wild-Allen, K.

    2016-02-01

    Observational and modelling systems provide two sources of knowledge that must be combined to provide a more complete view than either observations or models alone can provide. Here we describe the eReefs coupled hydrodynamic, sediment and biogeochemical model that has been developed for the Great Barrier Reef; and the multiple observations that are used to constrain the model. Two contrasting examples of model - observational integration are highlighted. First we explore the carbon chemistry of the waters above the reef, for which observations are accurate, but expensive and therefore sparse, while model behaviour is highly skilful. For carbon chemistry, observations are used to constrain model parameterisation and quantify model error, with the model output itself providing the most useable knowledge for management purposes. In contrast, ocean colour provides inaccurate, but cheap and spatially and temporally extensive observations. Thus observations are best combined with the model in a data assimilating framework, where a custom-designed optical model has been developed for the purposes of incorporating ocean colour observations. The future management of Great Barrier Reef water quality will be based on an integration of observing and modelling systems, providing the most robust information available.

  15. Benthic Foraminifera as ecological indicators for water quality on the Great Barrier Reef

    Science.gov (United States)

    Uthicke, Sven; Nobes, Kristie

    2008-07-01

    Benthic foraminifera are established indicators for Water Quality (WQ) in Florida and the Caribbean. However, nearshore coral reefs of the Great Barrier Reef (GBR) and other Pacific regions are also subjected to increased nutrient and sediment loads. Here, we investigate the use of benthic foraminifera as indicators to assess status and trends of WQ on GBR reefs. We quantified several sediment parameters and the foraminiferan assemblage composition on 20 reefs in four geographic regions of the GBR, and along a water column nutrient and turbidity gradient. Twenty-seven easily recognisable benthic foraminiferan taxa (>63 μm) were distinguished. All four geographic regions differed significantly ( p turbid inner shelf towards clearer outer shelf reefs. A RDA separated symbiotic and aposymbiotic (heterotrophic) taxa. In addition, total suspended solid and water column chlorophyll a concentrations were negatively correlated, and optical depth and distance to the mainland were positively correlated, with the abundance of symbiont-bearing taxa. Several large foraminifera were identified as indicators for offshore, clear water conditions. In contrast, heterotrophic rotaliids and a species retaining plastids ( Elphidium sp.) where highly characteristic for low light, higher nutrient conditions. Application of the FORAM index to GBR assemblage composition showed a significant increase in the value of this index with increased distance from the mainland in the Whitsunday region ( r2 = 0.75, p < 0.001), and therefore with increasing light and decreased nutrient availability. We conclude that it will be possible to apply this index to GBR and possibly other Pacific reefs after some adaptations and additional experimental work on species-specific limiting factors.

  16. Carbon Flux Through the Giant Barrel Sponge Xestospongia testudinaria in the Red Sea

    KAUST Repository

    Wooster, Michael K.

    2017-01-01

    Sponges have important ecological functions on coral reefs because they are regionally abundant, competitively dominant, and process large volumes of seawater. The sponge loop hypothesis proposes that sponges consume dissolved organic carbon (DOC

  17. Building resilience into practical conservation: identifying local management responses to global climate change in the southern Great Barrier Reef

    Science.gov (United States)

    Maynard, J. A.; Marshall, P. A.; Johnson, J. E.; Harman, S.

    2010-06-01

    Climate change is now considered the greatest long-term threat to coral reefs, with some future change inevitable despite mitigation efforts. Managers must therefore focus on supporting the natural resilience of reefs, requiring that resilient reefs and reef regions be identified. We develop a framework for assessing resilience and trial it by applying the framework to target management responses to climate change on the southern Great Barrier Reef. The framework generates a resilience score for a site based on the evaluation of 19 differentially weighted indicators known or thought to confer resilience to coral reefs. Scores are summed, and sites within a region are ranked in terms of (1) their resilience relative to the other sites being assessed, and (2) the extent to which managers can influence their resilience. The framework was applied to 31 sites in Keppel Bay of the southern Great Barrier Reef, which has a long history of disturbance and recovery. Resilience and ‘management influence potential’ were both found to vary widely in Keppel Bay, informing site selection for the staged implementation of resilience-based management strategies. The assessment framework represents a step towards making the concept of resilience operational to reef managers and conservationists. Also, it is customisable, easy to teach and implement and effective in building support among local communities and stakeholders for management responses to climate change.

  18. Molecular confirmation of hybridization between Dascyllus reticulatus × Dascyllus aruanus from the Great Barrier Reef

    KAUST Repository

    He, Song; Johansen, Jacob L.; Hoey, Andrew S.; Pappas, Melissa; Berumen, Michael L.

    2017-01-01

    To date, more than 81 species of tropical coral reef fish have been reported to hybridize in nature, spanning multiple families, including the Chaetodontidae, Pomacanthidae, and Labridae. Hybridization, however, is seemingly rare among benthic nesting species that engage in pair spawning, such as the Pomacentridae. Here, we present evidence for the first molecularly confirmed record of hybridization within the genus Dascyllus; D. aruanus and D. reticulatus. Interestingly, although many hybridization events are attributed to peripheral range effects or areas of limited overlap among otherwise allopatric species, this hybrid individual was collected from the northern Great Barrier Reef, centrally located within the distribution ranges of both species. The hybrid exhibited coloration and meristic counts intermediate between D. aruanus and D. reticulatus. Diagnostic genetic markers and subsequent microsatellites analysis confirmed that this individual was a hybrid offspring of D. aruanus and D. reticulatus, with the latter providing the maternal contribution. The occurrence of the D. aruanus × D. reticulatus hybrid on the Great Barrier Reef represents an exception to the otherwise species-specific haplotypes. The nuclear diagnostic marker which was identified during this study could serve as a hybrid indicator and benefit future hybrid investigations for hybridization between these two species.

  19. Molecular confirmation of hybridization between Dascyllus reticulatus × Dascyllus aruanus from the Great Barrier Reef

    KAUST Repository

    He, Song

    2017-11-17

    To date, more than 81 species of tropical coral reef fish have been reported to hybridize in nature, spanning multiple families, including the Chaetodontidae, Pomacanthidae, and Labridae. Hybridization, however, is seemingly rare among benthic nesting species that engage in pair spawning, such as the Pomacentridae. Here, we present evidence for the first molecularly confirmed record of hybridization within the genus Dascyllus; D. aruanus and D. reticulatus. Interestingly, although many hybridization events are attributed to peripheral range effects or areas of limited overlap among otherwise allopatric species, this hybrid individual was collected from the northern Great Barrier Reef, centrally located within the distribution ranges of both species. The hybrid exhibited coloration and meristic counts intermediate between D. aruanus and D. reticulatus. Diagnostic genetic markers and subsequent microsatellites analysis confirmed that this individual was a hybrid offspring of D. aruanus and D. reticulatus, with the latter providing the maternal contribution. The occurrence of the D. aruanus × D. reticulatus hybrid on the Great Barrier Reef represents an exception to the otherwise species-specific haplotypes. The nuclear diagnostic marker which was identified during this study could serve as a hybrid indicator and benefit future hybrid investigations for hybridization between these two species.

  20. Deepwater Chondrichthyan Bycatch of the Eastern King Prawn Fishery in the Southern Great Barrier Reef, Australia.

    Directory of Open Access Journals (Sweden)

    Cassandra L Rigby

    Full Text Available The deepwater chondrichthyan fauna of the Great Barrier Reef is poorly known and life history information is required to enable their effective management as they are inherently vulnerable to exploitation. The chondrichthyan bycatch from the deepwater eastern king prawn fishery at the Swain Reefs in the southern Great Barrier Reef was examined to determine the species present and provide information on their life histories. In all, 1533 individuals were collected from 11 deepwater chondrichthyan species, with the Argus skate Dipturus polyommata, piked spurdog Squalus megalops and pale spotted catshark Asymbolus pallidus the most commonly caught. All but one species is endemic to Australia with five species restricted to waters offshore from Queensland. The extent of life history information available for each species varied but the life history traits across all species were characteristic of deep water chondrichthyans with relatively large length at maturity, small litters and low ovarian fecundity; all indicative of low biological productivity. However, variability among these traits and spatial and bathymetric distributions of the species suggests differing degrees of resilience to fishing pressure. To ensure the sustainability of these bycatch species, monitoring of their catches in the deepwater eastern king prawn fishery is recommended.

  1. Keeping the ‘Great’ in the Great Barrier Reef: large-scale governance of the Great Barrier Reef Marine Park

    Directory of Open Access Journals (Sweden)

    Louisa S. Evans

    2014-08-01

    Full Text Available As part of an international collaboration to compare large-scale commons, we used the Social-Ecological Systems Meta-Analysis Database (SESMAD to systematically map out attributes of and changes in the Great Barrier Reef Marine Park (GBRMP in Australia. We focus on eight design principles from common-pool resource (CPR theory and other key social-ecological systems governance variables, and explore to what extent they help explain the social and ecological outcomes of park management through time. Our analysis showed that commercial fisheries management and the re-zoning of the GBRMP in 2004 led to improvements in ecological condition of the reef, particularly fisheries. These boundary and rights changes were supported by effective monitoring, sanctioning and conflict resolution. Moderate biophysical connectivity was also important for improved outcomes. However, our analysis also highlighted that continued challenges to improved ecological health in terms of coral cover and biodiversity can be explained by fuzzy boundaries between land and sea, and the significance of external drivers to even large-scale social-ecological systems (SES. While ecological and institutional fit in the marine SES was high, this was not the case when considering the coastal SES. Nested governance arrangements become even more important at this larger scale. To our knowledge, our paper provides the first analysis linking the re-zoning of the GBRMP to CPR and SES theory. We discuss important challenges to coding large-scale systems for meta-analysis.

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

    Science.gov (United States)

    Cantin, Neal E; Lough, Janice M

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-04-15

    Coral bleaching events threaten the sustainability of the Great Barrier Reef (GBR). Here we show that bleaching events of the past three decades have been mitigated by induced thermal tolerance of reef-building corals, and this protective mechanism is likely to be lost under near-future climate change scenarios. We show that 75% of past thermal stress events have been characterized by a temperature trajectory that subjects corals to a protective, sub-bleaching stress, before reaching temperatures that cause bleaching. Such conditions confer thermal tolerance, decreasing coral cell mortality and symbiont loss during bleaching by over 50%. We find that near-future increases in local temperature of as little as 0.5°C result in this protective mechanism being lost, which may increase the rate of degradation of the GBR. Copyright © 2016, American Association for the Advancement of Science.

  4. Phytotoxicity induced in isolated zooxanthellae by herbicides extracted from Great Barrier Reef flood waters.

    Science.gov (United States)

    Shaw, C M; Brodie, J; Mueller, J F

    2012-01-01

    To date there has been limited evidence anthropogenically sourced pollution from catchments reaching corals of the Great Barrier Reef (GBR). In this study, freshly isolated zooxanthellae were exposed to polar chemicals (chiefly herbicides) extracted from water samples collected in a flood plume in the GBR lagoon. Photosynthetic potential of the isolated zooxanthellae declined after exposure to concentrated extracts (10 times) from all but one of the sampling sites. Photosynthetic potential demonstrated a significant positive relationship with the concentration of diuron in the concentrated extracts and a significant inverse relationship with salinity measured at the sampling site. This study demonstrates that runoff from land based application of herbicides may reduce photosynthetic efficiency in corals of inshore reefs in the GBR. The ecological impacts of the chemicals in combination with other potential stressors on corals remain unclear. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2010-12-01

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

  6. Reef Sharks Exhibit Site-Fidelity and Higher Relative Abundance in Marine Reserves on the Mesoamerican Barrier Reef

    Science.gov (United States)

    Bond, Mark E.; Babcock, Elizabeth A.; Pikitch, Ellen K.; Abercrombie, Debra L.; Lamb, Norlan F.; Chapman, Demian D.

    2012-01-01

    Carcharhinid sharks can make up a large fraction of the top predators inhabiting tropical marine ecosystems and have declined in many regions due to intense fishing pressure. There is some support for the hypothesis that carcharhinid species that complete their life-cycle within coral reef ecosystems, hereafter referred to as “reef sharks”, are more abundant inside no-take marine reserves due to a reduction in fishing pressure (i.e., they benefit from marine reserves). Key predictions of this hypothesis are that (a) individual reef sharks exhibit high site-fidelity to these protected areas and (b) their relative abundance will generally be higher in these areas compared to fished reefs. To test this hypothesis for the first time in Caribbean coral reef ecosystems we combined acoustic monitoring and baited remote underwater video (BRUV) surveys to measure reef shark site-fidelity and relative abundance, respectively. We focused on the Caribbean reef shark (Carcharhinus perezi), the most common reef shark in the Western Atlantic, at Glover's Reef Marine Reserve (GRMR), Belize. Acoustically tagged sharks (N = 34) were detected throughout the year at this location and exhibited strong site-fidelity. Shark presence or absence on 200 BRUVs deployed at GRMR and three other sites (another reserve site and two fished reefs) showed that the factor “marine reserve” had a significant positive effect on reef shark presence. We rejected environmental factors or site-environment interactions as predominant drivers of this pattern. These results are consistent with the hypothesis that marine reserves can benefit reef shark populations and we suggest new hypotheses to determine the underlying mechanism(s) involved: reduced fishing mortality or enhanced prey availability. PMID:22412965

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  8. MtDNA barcode identification of fish larvae in the southern Great Barrier Reef – Australia

    Directory of Open Access Journals (Sweden)

    Graham G. Pegg

    2006-10-01

    Full Text Available Planktonic larvae were captured above a shallow coral reef study site on the Great Barrier Reef (GBR around spring-summer new moon periods (October-February using light trap or net capture devices. Larvae were identified to the genus or species level by comparison with a phylogenetic tree of tropical marine fish species using mtDNA HVR1 sequence data. Further analysis showed that within-species HVR1 sequence variation was typically 1-3%, whereas between-species variation for the same genus ranged up to 50%, supporting the suitability of HVR1 for species identification. Given the current worldwide interest in DNA barcoding and species identification using an alternative mtDNA gene marker (cox1, we also explored the efficacy of different primer sets for amplification of cox1 in reef fish, and its suitability for species identification. Of those tested, the Fish-F1 and -R1 primer set recently reported by Ward et al. (2005 gave the best results.

  9. Towards environmental management of water turbidity within open coastal waters of the Great Barrier Reef.

    Science.gov (United States)

    Macdonald, Rachael K; Ridd, Peter V; Whinney, James C; Larcombe, Piers; Neil, David T

    2013-09-15

    Water turbidity and suspended sediment concentration (SSC) are commonly used as part of marine monitoring and water quality plans. Current management plans utilise threshold SSC values derived from mean-annual turbidity concentrations. Little published work documents typical ranges of turbidity for reefs within open coastal waters. Here, time-series turbidity measurements from 61 sites in the Great Barrier Reef (GBR) and Moreton Bay, Australia, are presented as turbidity exceedance curves and derivatives. This contributes to the understanding of turbidity and SSC in the context of environmental management in open-coastal reef environments. Exceedance results indicate strong spatial and temporal variability in water turbidity across inter/intraregional scales. The highest turbidity across 61 sites, at 50% exceedance (T50) is 15.3 NTU and at 90% exceedance (T90) 4.1 NTU. Mean/median turbidity comparisons show strong differences between the two, consistent with a strongly skewed turbidity regime. Results may contribute towards promoting refinement of water quality management protocols. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Eddy covariance measurement of the spatial heterogeneity of surface energy exchanges over Heron Reef, Great Barrier Reef, Australia

    Science.gov (United States)

    MacKellar, M.; McGowan, H. A.; Phinn, S. R.

    2011-12-01

    Coral reefs cover 2.8 to 6.0 x 105 km2 of the Earth's surface and are warm, shallow regions that are believed to contribute enhanced sensible and latent heat to the atmosphere, relative to the surrounding ocean. To predict the impact of climate variability on coral reefs and their weather and climate including cloud, winds, rainfall patterns and cyclone genesis, accurate parameterisation of air-sea energy exchanges over coral reefs is essential. This is also important for the parameterisation and validation of regional to global scale forecast models to improve prediction of tropical and sub-tropical marine and coastal weather. Eddy covariance measurements of air-sea fluxes over coral reefs are rare due to the complexities of installing instrumentation over shallow, tidal water. Consequently, measurements of radiation and turbulent flux data for coral reefs have been captured remotely (satellite data) or via single measurement sites downwind of coral reefs (e.g. terrestrial or shipboard instrumentation). The resolution of such measurements and those that have been made at single locations on reefs may not capture the spatial heterogeneity of surface-atmosphere energy exchanges due to the different geomorphic and biological zones on coral reefs. Accordingly, the heterogeneity of coral reefs with regard to substrate, benthic communities and hydrodynamic processes are not considered in the characterization of the surface radiation energy flux transfers across the water-atmosphere interface. In this paper we present a unique dataset of concurrent in situ eddy covariance measurements made on instrumented pontoons of the surface energy balance over different geomorphic zones of a coral reef (shallow reef flat, shallow and deep lagoons). Significant differences in radiation transfers and air-sea turbulent flux exchanges over the reef were highlighted, with higher Bowen ratios over the shallow reef flat. Increasing wind speed was shown to increase flux divergence between

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

    Directory of Open Access Journals (Sweden)

    George Roff

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

  12. No gene flow across the Eastern Pacific Barrier in the reef-building coral Porites lobata.

    Science.gov (United States)

    Baums, Iliana B; Boulay, Jennifer N; Polato, Nicholas R; Hellberg, Michael E

    2012-11-01

    The expanse of deep water between the central Pacific islands and the continental shelf of the Eastern Tropical Pacific is regarded as the world's most potent marine biogeographic barrier. During recurrent climatic fluctuations (ENSO, El Niño Southern Oscillation), however, changes in water temperature and the speed and direction of currents become favourable for trans-oceanic dispersal of larvae from central Pacific to marginal eastern Pacific reefs. Here, we investigate the population connectivity of the reef-building coral Porites lobata across the Eastern Pacific Barrier (EPB). Patterns of recent gene flow in samples (n = 1173) from the central Pacific and the Eastern Tropical Pacific (ETP) were analysed with 12 microsatellite loci. Results indicated that P. lobata from the ETP are strongly isolated from those in the central Pacific and Hawaii (F(ct) ' = 0.509; P Clipperton Atoll, an oceanic island on the eastern side of the EPB, grouped with the central Pacific. Within the central Pacific, Hawaiian populations were strongly isolated from three co-occurring clusters found throughout the remainder of the central Pacific. No further substructure was evident in the ETP. Changes in oceanographic conditions during ENSO over the past several thousand years thus appear insufficient to support larval deliveries from the central Pacific to the ETP or strong postsettlement selection acts on ETP settlers from the central Pacific. Recovery of P. lobata populations in the frequently disturbed ETP thus must depend on local larval sources. © 2012 Blackwell Publishing Ltd.

  13. Sponge-microbe associations survive high nutrients and temperatures.

    Directory of Open Access Journals (Sweden)

    Rachel Simister

    Full Text Available Coral reefs are under considerable pressure from global stressors such as elevated sea surface temperature and ocean acidification, as well as local factors including eutrophication and poor water quality. Marine sponges are diverse, abundant and ecologically important components of coral reefs in both coastal and offshore environments. Due to their exceptionally high filtration rates, sponges also form a crucial coupling point between benthic and pelagic habitats. Sponges harbor extensive microbial communities, with many microbial phylotypes found exclusively in sponges and thought to contribute to the health and survival of their hosts. Manipulative experiments were undertaken to ascertain the impact of elevated nutrients and seawater temperature on health and microbial community dynamics in the Great Barrier Reef sponge Rhopaloeides odorabile. R. odorabile exposed to elevated nutrient levels including 10 µmol/L total nitrogen at 31°C appeared visually similar to those maintained under ambient seawater conditions after 7 days. The symbiotic microbial community, analyzed by 16S rRNA gene pyrotag sequencing, was highly conserved for the duration of the experiment at both phylum and operational taxonomic unit (OTU (97% sequence similarity levels with 19 bacterial phyla and 1743 OTUs identified across all samples. Additionally, elevated nutrients and temperatures did not alter the archaeal associations in R. odorabile, with sequencing of 16S rRNA gene libraries revealing similar Thaumarchaeota diversity and denaturing gradient gel electrophoresis (DGGE revealing consistent amoA gene patterns, across all experimental treatments. A conserved eukaryotic community was also identified across all nutrient and temperature treatments by DGGE. The highly stable microbial associations indicate that R. odorabile symbionts are capable of withstanding short-term exposure to elevated nutrient concentrations and sub-lethal temperatures.

  14. Intra-annual variation in turbidity in response to terrestrial runoff on near-shore coral reefs of the Great Barrier Reef

    Science.gov (United States)

    Fabricius, Katharina E.; De'ath, Glenn; Humphrey, Craig; Zagorskis, Irena; Schaffelke, Britta

    2013-01-01

    Seawater turbidity is a fundamental driver of the ecology of coastal marine systems, and is widely used as indicator for environmental reporting. However, the time scales and processes leading to changes in turbidity in tropical coastal waters remain poorly understood. This study investigates the main determinants of inshore turbidity in four inshore regions along ˜1000 km of the Australian Great Barrier Reef, based on ˜3 years of almost continuous in situ turbidity logger data on 14 reefs. Generalized additive mixed models were used to predict spatial and temporal variation in weekly mean turbidity based on variation in resuspension and runoff conditions. At any given wave height, wave period and tidal range, turbidity was significantly affected by river flow and rainfall. Averaged across all reefs, turbidity was 13% lower (range: 5-37%) in weeks with low compared with high rainfall and river flows. Additionally, turbidity was on average 43% lower 250 days into the dry season than at the start of the dry season on reefs with long-term mean turbidity >1.1 NTU. The data suggest the time scale of winnowing or consolidation of newly imported materials in this zone is months to years. In contrast, turbidity returned to low levels within weeks after river flows and rainfall on reefs with long-term mean turbidity of <1.1 NTU. Turbidity was also up to 10-fold higher on reefs near compared to away from river mouths, suggesting inter-annual accumulation of fine resuspendible sediments. The study suggests that a reduction in the river loads of fine sediments and nutrients through improved land management should lead to measurably improved inshore water clarity in the most turbid parts of the GBR.

  15. Sponge biomass and bioerosion rates increase under ocean warming and acidification.

    Science.gov (United States)

    Fang, James K H; Mello-Athayde, Matheus A; Schönberg, Christine H L; Kline, David I; Hoegh-Guldberg, Ove; Dove, Sophie

    2013-12-01

    The combination of ocean warming and acidification as a result of increasing atmospheric carbon dioxide (CO2 ) is considered to be a significant threat to calcifying organisms and their activities on coral reefs. How these global changes impact the important roles of decalcifying organisms (bioeroders) in the regulation of carbonate budgets, however, is less understood. To address this important question, the effects of a range of past, present and future CO2 emission scenarios (temperature + acidification) on the excavating sponge Cliona orientalis Thiele, 1900 were explored over 12 weeks in early summer on the southern Great Barrier Reef. C. orientalis is a widely distributed bioeroder on many reefs, and hosts symbiotic dinoflagellates of the genus Symbiodinium. Our results showed that biomass production and bioerosion rates of C. orientalis were similar under a pre-industrial scenario and a present day (control) scenario. Symbiodinium population density in the sponge tissue was the highest under the pre-industrial scenario, and decreased towards the two future scenarios with sponge replicates under the 'business-as-usual' CO2 emission scenario exhibiting strong bleaching. Despite these changes, biomass production and the ability of the sponge to erode coral carbonate materials both increased under the future scenarios. Our study suggests that C. orientalis will likely grow faster and have higher bioerosion rates in a high CO2 future than at present, even with significant bleaching. Assuming that our findings hold for excavating sponges in general, increased sponge biomass coupled with accelerated bioerosion may push coral reefs towards net erosion and negative carbonate budgets in the future. © 2013 John Wiley & Sons Ltd.

  16. The Gulf of Carpentaria heated Torres Strait and the Northern Great Barrier Reef during the 2016 mass coral bleaching event

    NARCIS (Netherlands)

    Wolanski, E.; Andutta, Fernando P.; Deleersnijder, E.L.C.; Li, Y.; Thomas, C.J.

    The 2015/16 ENSO event increased the temperature of waters surrounding northeast Australia to above 30 °C, with large patches of water reaching 32 °C, for over two months, which led to severe bleaching of corals of the Northern Great Barrier Reef (NGBR). This study provides evidence gained from

  17. New evidence of an early Pridoli barrier reef in the southern part of the Baltic Silurian basin based on three-dimensional seismic survey, Lithuania

    Directory of Open Access Journals (Sweden)

    Donatas Kaminskas

    2015-02-01

    Full Text Available Reefs and a barrier reef have been newly identified and mapped by three-dimensional (3D seismic survey in Lithuania. Seismic data analysis has allowed the size and geometry of these reefs to be determined. The largest reefs occur at Pavasaris and South Bliudziai. They have a similar shape and are about 1.5 km long and 1 km wide. A circle-shaped smaller patch reef at North Bliudziai is 1 km in diameter. The overall heights of the studied structures do not exceed 30–40 m. The reefs consist of coarse-grained bioclastic stromatoporoid limestone. A barrier reef rising structurally from SW to NE was established in the west of the mapped area. The stratigraphic position (early Minija Regional Stage and lateral distribution of the barrier reef suggest it started to form earlier than the group of patch reefs. The development of patch reefs was related to the transgression of the Silurian Baltic basin.

  18. ENSO Weather and Coral Bleaching on the Great Barrier Reef, Australia

    Science.gov (United States)

    McGowan, Hamish; Theobald, Alison

    2017-10-01

    The most devastating mass coral bleaching has occurred during El Niño events, with bleaching reported to be a direct result of increased sea surface temperatures (SSTs). However, El Niño itself does not cause SSTs to rise in all regions that experience bleaching. Nor is the upper ocean warming trend of 0.11°C per decade since 1971, attributed to global warming, sufficient alone to exceed the thermal tolerance of corals. Here we show that weather patterns during El Niño that result in reduced cloud cover, higher than average air temperatures and higher than average atmospheric pressures, play a crucial role in determining the extent and location of coral bleaching on the world's largest coral reef system, the World Heritage Great Barrier Reef (GBR), Australia. Accordingly, synoptic-scale weather patterns and local atmosphere-ocean feedbacks related to El Niño-Southern Oscillation (ENSO) and not large-scale SST warming due to El Niño alone and/or global warming are often the cause of coral bleaching on the GBR.

  19. Unique Sequence of Events Triggers Manta Ray Feeding Frenzy in the Southern Great Barrier Reef, Australia

    Directory of Open Access Journals (Sweden)

    Scarla J. Weeks

    2015-03-01

    Full Text Available Manta rays are classified as Vulnerable to Extinction on the IUCN Red List for Threatened Species. In Australia, a key aggregation site for reef manta rays is Lady Elliot Island (LEI on the Great Barrier Reef, ~7 km from the shelf edge. Here, we investigate the environmental processes that triggered the largest manta ray feeding aggregation yet observed in Australia, in early 2013. We use MODIS sea surface temperature (SST, chlorophyll-a concentration and photic depth data, together with in situ data, to show that anomalous river discharges led to high chlorophyll (anomalies: 10–15 mg∙m−3 and turbid (photic depth anomalies: −15 m river plumes extending out to LEI, and that these became entrained offshore around the periphery of an active cyclonic eddy. Eddy dynamics led to cold bottom intrusions along the shelf edge (6 °C temperature decrease, and at LEI (5 °C temperature decrease. Strongest SST gradients (>1 °C∙km−1 were at the convergent frontal zone between the shelf and eddy-influenced waters, directly overlying LEI. Here, the front intensified on the spring ebb tide to attract and shape the aggregation pattern of foraging manta rays. Future research could focus on mapping the probability and persistence of these ecologically significant frontal zones via remote sensing to aid the management and conservation of marine species.

  20. Understanding Biophysical Interactions In The Great Barrier Reef Catchments: Better Landscape Management For Water Quality Outcomes

    Science.gov (United States)

    Bui, E. N.; Wilkinson, S. N.; Bartley, R.

    2014-12-01

    Sediment input to the Great Barrier Reef (GBR) lagoon has had deleterious impacts on seagrass and coral ecosystems. The response of the Australian government has been to develop policies to: (i) reverse the impact of threats from sediments and nutrients, and improve water quality and aquatic health of the GBR lagoon; and (ii) to facilitate the uptake of sustainable farming and land management practices that deliver improved ecosystem services, by at least 30 per cent of farmers. The Reef2050 Long term sustainability plan aims to identify priority locations for on-ground investment of remediation options that will result in a reduction of constituent loads to the GBR. Recent sediment tracing studies indicate that subsoil from erosion features such as gullies and channel banks are the dominant contributors of sediment in the GBR catchments. Better control of gully and streambank erosion and restoration of riparian habitats are therefore necessary. Here we review the evidence for bank erosion in the GBR catchments and how scientific evidence on feedback relationships between climate- geochemistry-vegetation-landforms can be used to develop better guidelines for streambank and gully re-vegetation.

  1. Diversity and Activity of Diazotrophs in Great Barrier Reef Surface Waters.

    Science.gov (United States)

    Messer, Lauren F; Brown, Mark V; Furnas, Miles J; Carney, Richard L; McKinnon, A D; Seymour, Justin R

    2017-01-01

    Discrepancies between bioavailable nitrogen (N) concentrations and phytoplankton growth rates in the oligotrophic waters of the Great Barrier Reef (GBR) suggest that undetermined N sources must play a significant role in supporting primary productivity. One such source could be biological dinitrogen (N 2 ) fixation through the activity of "diazotrophic" bacterioplankton. Here, we investigated N 2 fixation and diazotroph community composition over 10° S of latitude within GBR surface waters. Qualitative N 2 fixation rates were found to be variable across the GBR but were relatively high in coastal, inner and outer GBR waters, reaching 68 nmol L -1 d -1 . Diazotroph assemblages, identified by amplicon sequencing of the nifH gene, were dominated by the cyanobacterium Trichodesmium erythraeum , γ-proteobacteria from the Gamma A clade, and δ-proteobacterial phylotypes related to sulfate-reducing genera. However, diazotroph communities exhibited significant spatial heterogeneity, correlated with shifts in dissolved inorganic nutrient concentrations. Specifically, heterotrophic diazotrophs generally increased in relative abundance with increasing concentrations of phosphate and N, while Trichodesmium was proportionally more abundant when concentrations of these nutrients were low. This study provides the first in-depth characterization of diazotroph community composition and N 2 fixation dynamics within the oligotrophic, N-limited surface waters of the GBR. Our observations highlight the need to re-evaluate N cycling dynamics within oligotrophic coral reef systems, to include diverse N 2 fixing assemblages as a potentially significant source of dissolved N within the water column.

  2. A method for risk analysis across governance systems: a Great Barrier Reef case study

    International Nuclear Information System (INIS)

    Dale, Allan; Vella, Karen; Potts, Ruth; Pressey, Robert L; Brodie, Jon; Yorkston, Hugh

    2013-01-01

    Healthy governance systems are key to delivering sound environmental management outcomes from global to local scales. There are, however, surprisingly few risk assessment methods that can pinpoint those domains and sub-domains within governance systems that are most likely to influence good environmental outcomes at any particular scale, or those if absent or dysfunctional, most likely to prevent effective environmental management. This paper proposes a new risk assessment method for analysing governance systems. This method is then tested through its preliminary application to a significant real-world context: governance as it relates to the health of Australia’s Great Barrier Reef (GBR). The GBR exists at a supra-regional scale along most of the north eastern coast of Australia. Brodie et al (2012 Mar. Pollut. Bull. 65 81–100) have recently reviewed the state and trend of the health of the GBR, finding that overall trends remain of significant concern. At the same time, official international concern over the governance of the reef has recently been signalled globally by the International Union for the Conservation of Nature (IUCN). These environmental and political contexts make the GBR an ideal candidate for use in testing and reviewing the application of improved tools for governance risk assessment. (letter)

  3. Joint estimation of crown of thorns (Acanthaster planci densities on the Great Barrier Reef

    Directory of Open Access Journals (Sweden)

    M. Aaron MacNeil

    2016-08-01

    Full Text Available Crown-of-thorns starfish (CoTS; Acanthaster spp. are an outbreaking pest among many Indo-Pacific coral reefs that cause substantial ecological and economic damage. Despite ongoing CoTS research, there remain critical gaps in observing CoTS populations and accurately estimating their numbers, greatly limiting understanding of the causes and sources of CoTS outbreaks. Here we address two of these gaps by (1 estimating the detectability of adult CoTS on typical underwater visual count (UVC surveys using covariates and (2 inter-calibrating multiple data sources to estimate CoTS densities within the Cairns sector of the Great Barrier Reef (GBR. We find that, on average, CoTS detectability is high at 0.82 [0.77, 0.87] (median highest posterior density (HPD and [95% uncertainty intervals], with CoTS disc width having the greatest influence on detection. Integrating this information with coincident surveys from alternative sampling programs, we estimate CoTS densities in the Cairns sector of the GBR averaged 44 [41, 48] adults per hectare in 2014.

  4. The demise of a major Acropora palmata bank-barrier reef off the southeast coast of Barbados, West Indies

    Science.gov (United States)

    MacIntyre, I. G.; Glynn, P. W.; Toscano, M. A.

    2007-12-01

    Formerly attributed to human activity, the demise of a bank-barrier reef off southeastern Barbados known as Cobbler’s Reef is now thought to be largely the result of late Holocene, millennial-scale storm damage. Eleven surface samples of the reef crest coral Acropora palmata from nine sites along its 15-km length plot above the western Atlantic sea-level curve from 3,000 to 4,500 cal years ago (calibrated, calendar 14C years). These elevated clusters suggest that the reef complex suffered extensive storm damage during this period. The constant heavy wave action typical of this area and consequent low herbivory maintain conditions favoring algal growth, thereby limiting the reestablishment of post-storm reef framework. Site descriptions and detailed line surveys show a surface now composed mainly of reworked fragments of A. palmata covered with algal turf, macroalgae and crustose coralline algae. The reef contains no live A. palmata and only a few scattered coral colonies consisting primarily of Diploria spp . and Porites astreoides, along with the hydrocoral Millepora complanata. A few in situ framework dates plot at expected depths for normal coral growth below the sea-level curve during and after the period of intense storm activity. The most recent of these in situ samples are 320 and 400 cal years old. Corals of this late period likely succumbed to high turbidity associated with land clearance for sugarcane agriculture in the mid-1600s.

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

    International Nuclear Information System (INIS)

    Lewis, S.E.; Brodie, J.E.; McCulloch, M.T.; Mallela, J.; Jupiter, S.D.; Stuart Williams, H.; Lough, J.M.; Matson, E.G.

    2012-01-01

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

  6. Guiding principles for the improved governance of port and shipping impacts in the Great Barrier Reef.

    Science.gov (United States)

    Grech, A; Bos, M; Brodie, J; Coles, R; Dale, A; Gilbert, R; Hamann, M; Marsh, H; Neil, K; Pressey, R L; Rasheed, M A; Sheaves, M; Smith, A

    2013-10-15

    The Great Barrier Reef (GBR) region of Queensland, Australia, encompasses a complex and diverse array of tropical marine ecosystems of global significance. The region is also a World Heritage Area and largely within one of the world's best managed marine protected areas. However, a recent World Heritage Committee report drew attention to serious governance problems associated with the management of ports and shipping. We review the impacts of ports and shipping on biodiversity in the GBR, and propose a series of guiding principles to improve the current governance arrangements. Implementing these principles will increase the capacity of decision makers to minimize the impacts of ports and shipping on biodiversity, and will provide certainty and clarity to port operators and developers. A 'business as usual' approach could lead to the GBR's inclusion on the List of World Heritage in Danger in 2014. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Dispersal of adult black marlin (Istiompax indica) from a Great Barrier Reef spawning aggregation.

    Science.gov (United States)

    Domeier, Michael L; Speare, Peter

    2012-01-01

    The black marlin (Istiompax indica) is one of the largest bony fishes in the world with females capable of reaching a mass of over 700 kg. This highly migratory predator occurs in the tropical regions of the Pacific and Indian Oceans, and is the target of regional recreational and commercial fisheries. Through the sampling of ichthyoplankton and ovaries we provide evidence that the relatively high seasonal abundance of black marlin off the Great Barrier Reef is, in fact, a spawning aggregation. Furthermore, through the tracking of individual black marlin via satellite popup tags, we document the dispersal of adult black marlin away from the spawning aggregation, thereby identifying the catchment area for this spawning stock. Although tag shedding is an issue when studying billfish, we tentatively identify the catchment area for this stock of black marlin to extend throughout the Coral Sea, including the waters of Papua New Guinea, the Solomon Islands, Micronesia, New Caledonia, Kiribati, Vanuatu, Fiji, Tuvalu and Nauru.

  8. Sensitivity of coral cays to climatic variations, southern Great Barrier Reef, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Flood, P G

    1986-01-01

    Analysis of available wind data for the years 1962-80 from Heron Island which is located within the southern Great Barrier Reef indicates that the annual wind energy vector has oscillated within a 45 degree arc from the SSE in the early 1960's to ESE in the late 1970's. Such changes in wind direction influence the direction of propagation of the waves which mold the shape of coral sand cays in this region. Documentation is provided which shows that the variability of the shoreline positions on Erskine Island, an uninhabited vegetated sand cays reflects this change. The implication is that contemporary shoreline erosion on Heron Island is not caused by the development associated with the tourist resort there. It is a symptom of the change in the propagation direction of the wind-induced waves which is related to long-term climatic change.

  9. Advances in monitoring the human dimension of natural resource systems: an example from the Great Barrier Reef

    Science.gov (United States)

    Marshall, N. A.; Bohensky, E.; Curnock, M.; Goldberg, J.; Gooch, M.; Nicotra, B.; Pert, P.; Scherl, L. M.; Stone-Jovicich, S.; Tobin, R. C.

    2016-11-01

    The aim of this paper is to demonstrate the feasibility and potential utility of decision-centric social-economic monitoring using data collected from Great Barrier Reef (Reef) region. The social and economic long term monitoring program (SELTMP) for the Reef is a novel attempt to monitor the social and economic dimensions of social-ecological change in a globally and nationally important region. It represents the current status and condition of the major user groups of the Reef with the potential to simultaneously consider trends, interconnections, conflicts, dependencies and vulnerabilities. Our approach was to combine a well-established conceptual framework with a strong governance structure and partnership arrangement that enabled the co-production of knowledge. The framework is a modification of the Millennium Ecosystem Assessment and it was used to guide indicator choice. Indicators were categorised as; (i) resource use and dependency, (ii) ecosystem benefits and well-being, and (iii) drivers of change. Data were collected through secondary datasets where existing and new datasets were created where not, using standard survey techniques. Here we present an overview of baseline results of new survey data from commercial-fishers (n = 210), marine-based tourism operators (n = 119), tourists (n = 2877), local residents (n = 3181), and other Australians (n = 2002). The indicators chosen describe both social and economic components of the Reef system and represent an unprecedented insight into the ways in which people currently use and depend on the Reef, the benefits that they derive, and how they perceive, value and relate to the Reef and each other. However, the success of a program such as the SELTMP can only occur with well-translated cutting-edge data and knowledge that are collaboratively produced, adaptive, and directly feeds into current management processes. We discuss how data from the SELTMP have already been incorporated into Reef management decision

  10. Ecosystem health of the Great Barrier Reef: Time for effective management action based on evidence

    Science.gov (United States)

    Brodie, Jon; Pearson, Richard G.

    2016-12-01

    The Great Barrier Reef (GBR) is a World Heritage site off the north-eastern coast of Australia. The GBR is worth A 15-20 billion/year to the Australian economy and provides approximately 64,000 full time jobs. Many of the species and ecosystems of the GBR are in poor condition and continue to decline. The principal causes of the decline are catchment pollutant runoff associated with agricultural and urban land uses, climate change impacts and the effects of fishing. Many important ecosystems of the GBR region are not included inside the boundaries of the World Heritage Area. The current management regime for catchment pollutant runoff and climate change is clearly inadequate to prevent further decline. We propose a refocus of management on a "Greater GBR" (containing not only the major ecosystems and species of the GBR, but also its catchment) and on a set of management actions to halt the decline of the GBR. Proposed actions include: (1) Strengthen management in the areas of the Greater GBR where ecosystems are in good condition, with Torres Strait, northern Cape York and Hervey Bay being the systems with highest current integrity; (2) Investigate methods of cross-boundary management to achieve simultaneous cost-effective terrestrial, freshwater and marine ecosystem protection in the Greater GBR; (3) Develop a detailed, comprehensive, costed water quality management plan for the Greater GBR; (4) Use the Great Barrier Reef Marine Park Act and the Environment Protection and Biodiversity Conservation Act to regulate catchment activities that lead to damage to the Greater GBR, in conjunction with the relevant Queensland legislation; (5) Fund catchment and coastal management to the required level to solve pollution issues for the Greater GBR by 2025, before climate change impacts on Greater GBR ecosystems become overwhelming; (6) Continue enforcement of the zoning plan; (7) Australia to show commitment to protecting the Greater GBR through greenhouse gas emissions

  11. Lower Mesophotic Coral Communities (60-125 m Depth of the Northern Great Barrier Reef and Coral Sea.

    Directory of Open Access Journals (Sweden)

    Norbert Englebert

    Full Text Available Mesophotic coral ecosystems in the Indo-Pacific remain relatively unexplored, particularly at lower mesophotic depths (≥60 m, despite their potentially large spatial extent. Here, we used a remotely operated vehicle to conduct a qualitative assessment of the zooxanthellate coral community at lower mesophotic depths (60-125 m at 10 different locations in the Great Barrier Reef Marine Park and the Coral Sea Commonwealth Marine Reserve. Lower mesophotic coral communities were present at all 10 locations, with zooxanthellate scleractinian corals extending down to ~100 metres on walls and ~125 m on steep slopes. Lower mesophotic coral communities were most diverse in the 60-80 m zone, while at depths of ≥100 m the coral community consisted almost exclusively of the genus Leptoseris. Collections of coral specimens (n = 213 between 60 and 125 m depth confirmed the presence of at least 29 different species belonging to 18 genera, including several potential new species and geographic/depth range extensions. Overall, this study highlights that lower mesophotic coral ecosystems are likely to be ubiquitous features on the outer reefs of the Great Barrier Reef and atolls of the Coral Sea, and harbour a generic and species richness of corals that is much higher than thus far reported. Further research efforts are urgently required to better understand and manage these ecosystems as part of the Great Barrier Reef Marine Park and Coral Sea Commonwealth Marine Reserve.

  12. Symbiodinium diversity among host clionaid sponges from Caribbean and Pacific reefs: Evidence of heteroplasmy and putative host-specific symbiont lineages.

    Science.gov (United States)

    Hill, Malcolm; Allenby, Ashley; Ramsby, Blake; Schönberg, Christine; Hill, April

    2011-04-01

    Among the Porifera, symbiosis with Symbiodinium spp. (i.e., zooxanthellae) is largely restricted to members of the family Clionaidae. We surveyed the diversity of zooxanthellae associated with sponges from the Caribbean and greater Indo-Pacific regions using chloroplast large subunit (cp23S) domain V sequences. We provide the first report of Clade C Symbiodinium harbored by a sponge (Cliona caesia), and the first report of Clade A Symbiodinium from an Indo-Pacific sponge (C. jullieni). Clade A zooxanthellae were also identified in sponges from the Caribbean, which has been reported previously. Sponges that we examined from the Florida Keys all harbored Clade G Symbiodinium as did C. orientalis from the Indo-Pacific, which also supports earlier work with sponges. Two distinct Clade G lineages were identified in our phylogenetic analysis; Symbiodinium extracted from clionaid sponges formed a monophyletic group sister to Symbiodinium found in foraminiferans. Truncated and 'normal' length variants of 23S rDNA sequences were detected simultaneously in all three morphotypes of C. varians providing the first evidence of chloroplast-based heteroplasmy in a sponge. None of the other sponge species examined showed evidence of heteroplasmy. As in previous work, length variation in cp23S domain V sequences was found to correspond in a highly precise manner to finer resolution of phylogenetic topology among Symbiodinium clades. On a global scale, existing data indicate that members of the family Clionaidae that host zooxanthellae can form symbiotic associations with at least four Symbiodinium clades. The majority of sponge hosts appear to harbor only one cladal type of symbiont, but some species can harbor more than one clade of zooxanthellae concurrently. The observed differences in the number of partners harbored by sponges raise important questions about the degree of coevolutionary integration and specificity of these symbioses. Although our sample sizes are small, we

  13. Anthropogenic contaminants in Indo-Pacific humpback and Australian snubfin dolphins from the central and southern Great Barrier Reef

    International Nuclear Information System (INIS)

    Cagnazzi, Daniele; Fossi, Maria Cristina; Parra, Guido J.; Harrison, Peter L.; Maltese, Silvia; Coppola, Daniele; Soccodato, Alice; Bent, Michael; Marsili, Letizia

    2013-01-01

    We present the first evidence of accumulation of organochlorine compounds (DDTs, PCBs, HCB) and polycyclic aromatic hydrocarbons (PAHs) in Indo-Pacific humpback and Australian snubfin dolphins from the central and southern Great Barrier Reef. These dolphins are considered by the Great Barrier Marine Park Authority to be high priority species for management. Analyses of biopsy samples, collected from free ranging individuals, showed PAHs levels comparable to those reported from highly industrialized countries. DDTs and HCB were found at low levels, while in some individuals, PCBs were above thresholds over which immunosuppression and reproductive anomalies occur. These results highlight the need for ongoing monitoring of these and other contaminants, and their potential adverse effects on dolphins and other marine fauna. This is particularly important given the current strategic assessment of the Great Barrier Reef World Heritage Area being undertaken by the Australian Government and the Queensland Government. -- Potentially hazardous levels of some coastal contaminants were found in two species of dolphins inhabiting the Great Barrier Reef Marine Park coastal region

  14. Diuron tolerance and potential degradation by pelagic microbiomes in the Great Barrier Reef lagoon

    Directory of Open Access Journals (Sweden)

    Florent E. Angly

    2016-03-01

    Full Text Available Diuron is a herbicide commonly used in agricultural areas where excess application causes it to leach into rivers, reach sensitive marine environments like the Great Barrier Reef (GBR lagoon and pose risks to marine life. To investigate the impact of diuron on whole prokaryotic communities that underpin the marine food web and are integral to coral reef health, GBR lagoon water was incubated with diuron at environmentally-relevant concentration (8 µg/L, and sequenced at specific time points over the following year. 16S rRNA gene amplicon profiling revealed no significant short- or long-term effect of diuron on microbiome structure. The relative abundance of prokaryotic phototrophs was not significantly altered by diuron, which suggests that they were largely tolerant at this concentration. Assembly of a metagenome derived from waters sampled at a similar location in the GBR lagoon did not reveal the presence of mutations in the cyanobacterial photosystem that could explain diuron tolerance. However, resident phages displayed several variants of this gene and could potentially play a role in tolerance acquisition. Slow biodegradation of diuron was reported in the incubation flasks, but no correlation with the relative abundance of heterotrophs was evident. Analysis of metagenomic reads supports the hypothesis that previously uncharacterized hydrolases carried by low-abundance species may mediate herbicide degradation in the GBR lagoon. Overall, this study offers evidence that pelagic phototrophs of the GBR lagoon may be more tolerant of diuron than other tropical organisms, and that heterotrophs in the microbial seed bank may have the potential to degrade diuron and alleviate local anthropogenic stresses to inshore GBR ecosystems.

  15. Diuron tolerance and potential degradation by pelagic microbiomes in the Great Barrier Reef lagoon

    Science.gov (United States)

    Pantos, Olga; Morgan, Thomas C.; Rich, Virginia; Tonin, Hemerson; Bourne, David G.; Mercurio, Philip; Negri, Andrew P.; Tyson, Gene W.

    2016-01-01

    Diuron is a herbicide commonly used in agricultural areas where excess application causes it to leach into rivers, reach sensitive marine environments like the Great Barrier Reef (GBR) lagoon and pose risks to marine life. To investigate the impact of diuron on whole prokaryotic communities that underpin the marine food web and are integral to coral reef health, GBR lagoon water was incubated with diuron at environmentally-relevant concentration (8 µg/L), and sequenced at specific time points over the following year. 16S rRNA gene amplicon profiling revealed no significant short- or long-term effect of diuron on microbiome structure. The relative abundance of prokaryotic phototrophs was not significantly altered by diuron, which suggests that they were largely tolerant at this concentration. Assembly of a metagenome derived from waters sampled at a similar location in the GBR lagoon did not reveal the presence of mutations in the cyanobacterial photosystem that could explain diuron tolerance. However, resident phages displayed several variants of this gene and could potentially play a role in tolerance acquisition. Slow biodegradation of diuron was reported in the incubation flasks, but no correlation with the relative abundance of heterotrophs was evident. Analysis of metagenomic reads supports the hypothesis that previously uncharacterized hydrolases carried by low-abundance species may mediate herbicide degradation in the GBR lagoon. Overall, this study offers evidence that pelagic phototrophs of the GBR lagoon may be more tolerant of diuron than other tropical organisms, and that heterotrophs in the microbial seed bank may have the potential to degrade diuron and alleviate local anthropogenic stresses to inshore GBR ecosystems. PMID:26989611

  16. Diuron tolerance and potential degradation by pelagic microbiomes in the Great Barrier Reef lagoon.

    Science.gov (United States)

    Angly, Florent E; Pantos, Olga; Morgan, Thomas C; Rich, Virginia; Tonin, Hemerson; Bourne, David G; Mercurio, Philip; Negri, Andrew P; Tyson, Gene W

    2016-01-01

    Diuron is a herbicide commonly used in agricultural areas where excess application causes it to leach into rivers, reach sensitive marine environments like the Great Barrier Reef (GBR) lagoon and pose risks to marine life. To investigate the impact of diuron on whole prokaryotic communities that underpin the marine food web and are integral to coral reef health, GBR lagoon water was incubated with diuron at environmentally-relevant concentration (8 µg/L), and sequenced at specific time points over the following year. 16S rRNA gene amplicon profiling revealed no significant short- or long-term effect of diuron on microbiome structure. The relative abundance of prokaryotic phototrophs was not significantly altered by diuron, which suggests that they were largely tolerant at this concentration. Assembly of a metagenome derived from waters sampled at a similar location in the GBR lagoon did not reveal the presence of mutations in the cyanobacterial photosystem that could explain diuron tolerance. However, resident phages displayed several variants of this gene and could potentially play a role in tolerance acquisition. Slow biodegradation of diuron was reported in the incubation flasks, but no correlation with the relative abundance of heterotrophs was evident. Analysis of metagenomic reads supports the hypothesis that previously uncharacterized hydrolases carried by low-abundance species may mediate herbicide degradation in the GBR lagoon. Overall, this study offers evidence that pelagic phototrophs of the GBR lagoon may be more tolerant of diuron than other tropical organisms, and that heterotrophs in the microbial seed bank may have the potential to degrade diuron and alleviate local anthropogenic stresses to inshore GBR ecosystems.

  17. In the other 90%: phytoplankton responses to enhanced nutrient availability in the Great Barrier Reef Lagoon

    International Nuclear Information System (INIS)

    Furnas, Miles; Mitchell, Alan; Skuza, Michele; Brodie, Jon

    2005-01-01

    Our view of how water quality effects ecosystems of the Great Barrier Reef (GBR) is largely framed by observed or expected responses of large benthic organisms (corals, algae, seagrasses) to enhanced levels of dissolved nutrients, sediments and other pollutants in reef waters. In the case of nutrients, however, benthic organisms and communities are largely responding to materials which have cycled through and been transformed by pelagic communities dominated by micro-algae (phytoplankton), protozoa, flagellates and bacteria. Because GBR waters are characterised by high ambient light intensities and water temperatures, inputs of nutrients from both internal and external sources are rapidly taken up and converted to organic matter in inter-reefal waters. Phytoplankton growth, pelagic grazing and remineralisation rates are very rapid. Dominant phytoplankton species in GBR waters have in situ growth rates which range from ∼1 to several doublings per day. To a first approximation, phytoplankton communities and their constituent nutrient content turn over on a daily basis. Relative abundances of dissolved nutrient species strongly indicate N limitation of new biomass formation. Direct ( 15 N) and indirect ( 14 C) estimates of N demand by phytoplankton indicate dissolved inorganic N pools have turnover times on the order of hours to days. Turnover times for inorganic phosphorus in the water column range from hours to weeks. Because of the rapid assimilation of nutrients by plankton communities, biological responses in benthic communities to changed water quality are more likely driven (at several ecological levels) by organic matter derived from pelagic primary production than by dissolved nutrient stocks alone

  18. Utility of Photochemical Traits as Diagnostics of Thermal Tolerance amongst Great Barrier Reef Corals

    Directory of Open Access Journals (Sweden)

    Matthew R. Nitschke

    2018-02-01

    Full Text Available Light availability is considered a key factor regulating the thermal sensitivity of reef building corals, where excessive excitation of photosystem II (PSII further exacerbates pressure on photochemical pathways already compromised by heat stress. Coral symbionts acclimate to changes in light availability (photoacclimation by continually fine-tuning the photochemical operating efficiency of PSII. However, how this process adjusts throughout the warmest months in naturally heat-tolerant or sensitive species is unknown, and whether this influences the capacity to tolerate transient heat stress is untested. We therefore examined the PSII photophysiology of 10 coral species (with known thermal tolerances from shallow reef environments at Heron Island (Great Barrier Reef, Australia, in spring (October-November, 2015 vs. summer (February-March, 2016. Corals were maintained in flow-through aquaria and rapid light curve (RLC protocols using pulse amplitude modulated (PAM fluorometry captured changes in the PSII photoacclimation strategy, characterized as the minimum saturating irradiance (Ek, and the extent of photochemical ([1 – C], operating efficiency vs. non-photochemical ([1 – Q] energy dissipation. Values of Ek across species were >2-fold higher in all coral species in spring, consistent with a climate of higher overall light exposure (i.e., higher PAR from lower cloud cover, rainfall and wind speed compared with summer. Summer decreases in Ek were combined with a shift toward preferential photochemical quenching in all species. All coral species were subsequently subjected to thermal stress assays. An equivalent temperature-ramping profile of 1°C increase per day and then maintenance at 32°C was applied in each season. Despite the significant seasonal photoacclimation, the species hierarchy of thermal tolerance [maximum quantum yields of PSII (Fv/Fm, monitored at dawn and dusk] did not shift between seasons, except for Pocillopora

  19. CaCO3 dissolution by holothurians (sea cucumber): a case study from One Tree Reef, Great Barrier Reef

    Science.gov (United States)

    Schneider, K.; Silverman, J.; Kravitz, B.; Woolsey, E.; Eriksson, H.; Schneider-Mor, A.; Barbosa, S.; Rivlin, T.; Byrne, M.; Caldeira, K.

    2012-12-01

    Holothurians (sea cucumbers) are among the largest and most important deposit feeder in coral reefs. They play a role in nutrient and CaCO3 cycling within the reef structure. As a result of their digestive process they secrete alkalinity due to CaCO3 dissolution and organic matter degradation forming CO2 and ammonium. In a survey at station DK13 on One Three Reef we found that the population density of holothurians was > 1 individual m-2. The dominant sea cucumber species Holothuria leucospilota was collected from DK13. The increase in alkalinity due to CaCO3 dissolution in aquaria incubations was measured to be 47±7 μmol kg-1 in average per individual. Combining this dissolution rate with the sea cucumbers concentrations at DK13 suggest that they may account for a dissolution rate of 34.9±17.8 mmol m-2 day-1, which is equivalent to about half of night time community dissolution measured in DK13. This indicates that in reefs where the sea cucumber population is healthy and protected from fishing they can be locally important in the CaCO3 cycle. Preliminary result suggests that the CaCO3 dissolution rates are not affected by the chemistry of the sea water they are incubated in. Measurements of the empty digestive track volume of two sea cucumbers H. atra and Stichopus herrmanni were 36 ± 4 ml and 151 ± 14 ml, respectively. Based on these measurements it is estimated that these species process 19 ± 2kg and 80 ± 7kg CaCO3 sand yr-1 per individual, respectively. The annual dissolution rates of H. atra and S. herrmanni are 6.5±1.9g and 9.6±1.4g, respectively, suggest that 0.05±0.02% and 0.1±0.02% of the CaCO3 processed through their gut annually is dissolved. During the incubations the CaCO3 dissolution was 0.07±0.01%, 0.04±0.01% and 0.21±0.05% of the fecal casts for H. atra, H. leucospilota and S. herrmanni, respectively. Our result that the primary parameter determining the CaCO3 dissolution by sea cucumber is the amount of carbonate send in their gut

  20. Biology and ecology of the vulnerable holothuroid, Stichopus herrmanni, on a high-latitude coral reef on the Great Barrier Reef

    Science.gov (United States)

    Wolfe, Kennedy; Byrne, Maria

    2017-12-01

    Tropical aspidochirotid holothuroids are among the largest coral reef invertebrates, but gaps remain in our understanding of their ecological roles in lagoon sediment habitats, a vast component of coral-reef ecosystems. Stichopus herrmanni, listed as vulnerable (IUCN), is currently a major fishery species on the Great Barrier Reef (GBR) and throughout the Indo-Pacific. It is critical to characterise how this species interacts with its environment to understand how its removal may impact ecosystem functionality. We investigated seasonal variation in movement, bioturbation, feeding and gonad development of S. herrmanni over 3 yr at One Tree Reef, which has been a no-take area for decades. We determined the direct influence of the deposit-feeding activity of S. herrmanni on sediment turnover and granulometry, and on the abundance of infauna and benthic productivity in a comprehensive in situ analysis of tropical holothuroid feeding ecology. This species is highly mobile with identifiable individuals exhibiting site fidelity over 3 yr. With the potential to turn over an estimated 64-250 kg individual-1 yr-1, S. herrmanni is a major bioturbator. Stichopus herrmanni is a generalist feeder and influences trophic interactions by altering the abundance of infauna and microalgae. Stichopus herrmanni exhibited decreased feeding activity and gonad development in winter, the first documentation of a seasonal disparity in the bioturbation activity of a tropical holothuroid. Sediment digestion and dissolution by S. herrmanni has the potential to influence seawater chemistry, a particularly important feature in a changing ocean. Our results provide essential baseline data on the functional roles of this ecologically important species to inform development of ecosystem-based bêche-de-mer fisheries management on the GBR.

  1. Avoiding Implementation Failure in Catchment Landscapes: A Case Study in Governance of the Great Barrier Reef.

    Science.gov (United States)

    Dale, Allan P; Vella, Karen; Gooch, Margaret; Potts, Ruth; Pressey, Robert L; Brodie, Jon; Eberhard, Rachel

    2017-10-04

    Water quality outcomes affecting Australia's Great Barrier Reef (GBR) are governed by multi-level and multi-party decision-making that influences forested and agricultural landscapes. With international concern about the GBR's declining ecological health, this paper identifies and focuses on implementation failure (primarily at catchment scale) as a systemic risk within the overall GBR governance system. There has been limited integrated analysis of the full suite of governance subdomains that often envelop defined policies, programs and delivery activities that influence water quality in the GBR. We consider how the implementation of separate purpose-specific policies and programs at catchment scale operate against well-known, robust design concepts for integrated catchment governance. We find design concerns within ten important governance subdomains that operate within GBR catchments. At a whole-of-GBR scale, we find a weak policy focus on strengthening these delivery-oriented subdomains and on effort integration across these subdomains within catchments. These governance problems when combined may contribute to failure in the implementation of major national, state and local government policies focused on improving water quality in the GBR, a lesson relevant to landscapes globally.

  2. Structural and Psycho-Social Limits to Climate Change Adaptation in the Great Barrier Reef Region.

    Science.gov (United States)

    Evans, Louisa S; Hicks, Christina C; Adger, W Neil; Barnett, Jon; Perry, Allison L; Fidelman, Pedro; Tobin, Renae

    2016-01-01

    Adaptation, as a strategy to respond to climate change, has limits: there are conditions under which adaptation strategies fail to alleviate impacts from climate change. Research has primarily focused on identifying absolute bio-physical limits. This paper contributes empirical insight to an emerging literature on the social limits to adaptation. Such limits arise from the ways in which societies perceive, experience and respond to climate change. Using qualitative data from multi-stakeholder workshops and key-informant interviews with representatives of the fisheries and tourism sectors of the Great Barrier Reef region, we identify psycho-social and structural limits associated with key adaptation strategies, and examine how these are perceived as more or less absolute across levels of organisation. We find that actors experience social limits to adaptation when: i) the effort of pursuing a strategy exceeds the benefits of desired adaptation outcomes; ii) the particular strategy does not address the actual source of vulnerability, and; iii) the benefits derived from adaptation are undermined by external factors. We also find that social limits are not necessarily more absolute at higher levels of organisation: respondents perceived considerable opportunities to address some psycho-social limits at the national-international interface, while they considered some social limits at the local and regional levels to be effectively absolute.

  3. The effects of river run-off on water clarity across the central Great Barrier Reef.

    Science.gov (United States)

    Fabricius, K E; Logan, M; Weeks, S; Brodie, J

    2014-07-15

    Changes in water clarity across the shallow continental shelf of the central Great Barrier Reef were investigated from ten years of daily river load, oceanographic and MODIS-Aqua data. Mean photic depth (i.e., the depth of 10% of surface irradiance) was related to river loads after statistical removal of wave and tidal effects. Across the ∼25,000 km(2) area, photic depth was strongly related to river freshwater and phosphorus loads (R(2)=0.65 and 0.51, respectively). In the six wetter years, photic depth was reduced by 19.8% and below water quality guidelines for 156 days, compared to 9 days in the drier years. After onset of the seasonal river floods, photic depth was reduced for on average 6-8 months, gradually returning to clearer baseline values. Relationships were strongest inshore and midshelf (∼12-80 km from the coast), and weaker near the chronically turbid coast. The data show that reductions in river loads would measurably improve shelf water clarity, with significant ecosystem health benefits. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  4. Structural and Psycho-Social Limits to Climate Change Adaptation in the Great Barrier Reef Region.

    Directory of Open Access Journals (Sweden)

    Louisa S Evans

    Full Text Available Adaptation, as a strategy to respond to climate change, has limits: there are conditions under which adaptation strategies fail to alleviate impacts from climate change. Research has primarily focused on identifying absolute bio-physical limits. This paper contributes empirical insight to an emerging literature on the social limits to adaptation. Such limits arise from the ways in which societies perceive, experience and respond to climate change. Using qualitative data from multi-stakeholder workshops and key-informant interviews with representatives of the fisheries and tourism sectors of the Great Barrier Reef region, we identify psycho-social and structural limits associated with key adaptation strategies, and examine how these are perceived as more or less absolute across levels of organisation. We find that actors experience social limits to adaptation when: i the effort of pursuing a strategy exceeds the benefits of desired adaptation outcomes; ii the particular strategy does not address the actual source of vulnerability, and; iii the benefits derived from adaptation are undermined by external factors. We also find that social limits are not necessarily more absolute at higher levels of organisation: respondents perceived considerable opportunities to address some psycho-social limits at the national-international interface, while they considered some social limits at the local and regional levels to be effectively absolute.

  5. Dispersal of adult black marlin (Istiompax indica from a Great Barrier Reef spawning aggregation.

    Directory of Open Access Journals (Sweden)

    Michael L Domeier

    Full Text Available The black marlin (Istiompax indica is one of the largest bony fishes in the world with females capable of reaching a mass of over 700 kg. This highly migratory predator occurs in the tropical regions of the Pacific and Indian Oceans, and is the target of regional recreational and commercial fisheries. Through the sampling of ichthyoplankton and ovaries we provide evidence that the relatively high seasonal abundance of black marlin off the Great Barrier Reef is, in fact, a spawning aggregation. Furthermore, through the tracking of individual black marlin via satellite popup tags, we document the dispersal of adult black marlin away from the spawning aggregation, thereby identifying the catchment area for this spawning stock. Although tag shedding is an issue when studying billfish, we tentatively identify the catchment area for this stock of black marlin to extend throughout the Coral Sea, including the waters of Papua New Guinea, the Solomon Islands, Micronesia, New Caledonia, Kiribati, Vanuatu, Fiji, Tuvalu and Nauru.

  6. Understanding Recreational Fishers' Compliance with No-take Zones in the Great Barrier Reef Marine Park

    Directory of Open Access Journals (Sweden)

    Adrian Arias

    2013-12-01

    Full Text Available Understanding fishers' compliance is essential for the successful management of marine protected areas. We used the random response technique (RRT to assess recreational fishers' compliance with no-take zones in the Great Barrier Reef Marine Park (GBRMP. The RRT allowed the asking of a sensitive question, i.e., "Did you, knowingly, fish within in a Green Zone during the last 12 months?" while protecting respondents' confidentiality. Application of the RRT through a survey of recreational fishers indicated that the majority of recreational fishers, 90%, comply with no-take zones. Likewise, most fishers, 92%, reported not personally knowing anyone who had intentionally fished in a no-take zone, indicating that fishers' perceive high levels of compliance among their peers. Fishers were motivated to comply with no-take zones primarily by their beliefs about penalties for noncompliance, followed by beliefs about the fishery benefits of no-take zones. Results suggest that compliance-related communication efforts by the managing authority have partially succeeded in maintaining appropriate compliance levels and that future efforts should accentuate normative compliance drivers that will encourage voluntary compliance. We conclude that compliance monitoring should be integrated into the adaptive management of the GBRMP and other protected areas; in this case social surveys using the RRT are effective tools.

  7. The importance of coral larval recruitment for the recovery of reefs impacted by cyclone Yasi in the central Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Vimoksalehi Lukoschek

    Full Text Available Cyclone Yasi, one of the most severe tropical storms on record, crossed the central Great Barrier Reef (GBR in February 2011, bringing wind speeds of up to 285 km hr⁻¹ and wave heights of at least 10 m, and causing massive destruction to exposed reefs in the Palm Island Group. Following the cyclone, mean (± S.E. hard coral cover ranged from just 2.1 (0.2 % to 5.3 (0.4 % on exposed reefs and no reproductively mature colonies of any species of Acropora remained. Although no fragments of Acropora were found at impacted exposed sites following the cyclone, small juvenile colonies of Acropora (<10 cm diameter were present, suggesting that their small size and compact morphologies enabled them to survive the cyclone. By contrast, sheltered reefs appeared to be unaffected by the cyclone. Mean (± S.E. hard coral cover ranged from 18.2 (2.4 % to 30.0 (1.0 % and a large proportion of colonies of Acropora were reproductively mature. Macroalgae accounted for 8 to 16% of benthic cover at exposed sites impacted by cyclone Yasi but were absent at sheltered sites. Mean (± S.E. recruitment of acroporids to settlement tiles declined from 25.3 (4.8 recruits tile⁻¹ in the pre-cyclone spawning event (2010 to 15.4 (2.2 recruits tile⁻¹ in the first post-cyclone spawning event (2011. Yet, post-cyclone recruitment did not differ between exposed (15.2±2.1 S.E. and sheltered sites (15.6±2.2 S.E., despite the loss of reproductive colonies at the exposed sites, indicating larval input from external sources. Spatial variation in impacts, the survival of small colonies, and larval replenishment to impacted reefs suggest that populations of Acropora have the potential to recover from this severe disturbance, provided that the Palm Islands are not impacted by acute disturbances or suffer additional chronic stressors in the near future.

  8. A population genetic assessment of coral recovery on highly disturbed reefs of the Keppel Island archipelago in the southern Great Barrier Reef

    Directory of Open Access Journals (Sweden)

    Madeleine J.H. van Oppen

    2015-07-01

    Full Text Available Coral reefs surrounding the islands lying close to the coast are unique to the Great Barrier Reef (GBR in that they are frequently exposed to disturbance events including floods caused by cyclonic rainfall, strong winds and occasional periods of prolonged above-average temperatures during summer. In one such group of islands in the southern GBR, the Keppel Island archipelago, climate-driven disturbances frequently result in major coral mortality. Whilst these island reefs have clearly survived such dramatic disturbances in the past, the consequences of extreme mortality events may include the loss of genetic diversity, and hence adaptive potential, and a reduction in fitness due to inbreeding, especially if new recruitment from external sources is limited. Here we examined the level of isolation of the Keppel Island group as well as patterns of gene flow within the Keppel Islands using 10 microsatellite markers in nine populations of the coral, Acropora millepora. Bayesian cluster analysis and assignment tests indicated gene flow is restricted, but not absent, between the outer and inner Keppel Island groups, and that extensive gene flow exists within each of these island groups. Comparison of the Keppel Island data with results from a previous GBR-wide study that included a single Keppel Island population, confirmed that A. millepora in the Keppel Islands is genetically distinct from populations elsewhere on the GBR, with exception of the nearby inshore High Peak Reef just north of the Keppel Islands. We compared patterns of genetic diversity in the Keppel Island populations with those from other GBR populations and found them to be slightly, but significantly lower, consistent with the archipelago being geographically isolated, but there was no evidence for recent bottlenecks or deviation from mutation-drift equilibrium. A high incidence of private alleles in the Keppel Islands, particularly in the outer islands, supports their relative

  9. Geographic and habitat partitioning of genetically distinct zooxanthellae (Symbiodinium) in Acropora corals on the Great Barrier Reef.

    Science.gov (United States)

    Ulstrup, K E; Van Oppen, M J H

    2003-12-01

    Intra- and intercolony diversity and distribution of zooxanthellae in acroporid corals is largely uncharted. In this study, two molecular methods were applied to determine the distribution of zooxanthellae in the branching corals Acropora tenuis and A. valida at several reef locations in the central section of the Great Barrier Reef. Sun-exposed and shaded parts of all colonies were examined. Single-stranded conformational polymorphism analysis showed that individual colonies of A. tenuis at two locations harbour two strains of Symbiodinium belonging to clade C (C1 and C2), whereas conspecific colonies at two other reefs harboured a single zooxanthella strain. A. valida was found to simultaneously harbour strains belonging to two distinct phylogenetic clades (C and D) at all locations sampled. A novel method with improved sensitivity (quantitative polymerase chain reaction using Taqman fluorogenic probes) was used to map the relative abundance distribution of the two zooxanthella clades. At two of the five sampling locations both coral species were collected. At these two locations, composition of the zooxanthella communities showed the same pattern in both coral species, i.e. correlation with ambient light in Pioneer Bay and an absence thereof in Nelly Bay. The results show that the distribution of genetically distinct zooxanthellae is correlated with light regime and possibly temperature in some (but not all) colonies of A. tenuis and A. valida and at some reef locations, which we interpret as acclimation to local environmental conditions.

  10. RESEARCH: Influence of Social, Biophysical, and Managerial Conditions on Tourism Experiences Within the Great Barrier Reef World Heritage Area.

    Science.gov (United States)

    Shafer; Inglis

    2000-07-01

    / Managing protected areas involves balancing the enjoyment of visitors with the protection of a variety of cultural and biophysical resources. Tourism pressures in the Great Barrier Reef World Heritage Area (GBRWHA) are creating concerns about how to strike this balance in a marine environment. Terrestrial-based research has led to conceptual planning and management frameworks that address issues of human use and resource protection. The limits of acceptable change (LAC) framework was used as a conceptual basis for a study of snorkeling at reef sites in the GBRWHA. The intent was to determine if different settings existed among tourism operators traveling to the reef and, if so, to identify specific conditions relating to those settings. Snorkelers (N = 1475) traveling with tourism operations of different sizes who traveled to different sites completed surveys. Results indicated that snorkelers who traveled with larger operations (more people and infrastructure) differed from those traveling with smaller operations (few people and little on-site infrastructure) on benefits received and in the way that specific conditions influenced their enjoyment. Benefits related to nature, escape, and family helped to define reef experiences. Conditions related to coral, fish, and operator staff had a positive influence on the enjoyment of most visitors but, number of people on the trip and site infrastructure may have the greatest potential as setting indicators. Data support the potential usefulness of visitor input in applying the LAC concept to a marine environment where tourism and recreational uses are rapidly changing.

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

    Science.gov (United States)

    Rolfe, John; Windle, Jill

    2011-12-01

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

  12. Monitoring the environment and human sentiment on the Great Barrier Reef: Assessing the potential of collective sensing.

    Science.gov (United States)

    Becken, Susanne; Stantic, Bela; Chen, Jinyan; Alaei, Ali Reza; Connolly, Rod M

    2017-12-01

    With the growth of smartphone usage the number of social media posts has significantly increased and represents potentially valuable information for management, including of natural resources and the environment. Already, evidence of using 'human sensor' in crises management suggests that collective knowledge could be used to complement traditional monitoring. This research uses Twitter data posted from the Great Barrier Reef region, Australia, to assess whether the extent and type of data could be used to Great Barrier Reef organisations as part of their monitoring program. The analysis reveals that large amounts of tweets, covering the geographic area of interest, are available and that the pool of information providers is greatly enhanced by the large number of tourists to this region. A keyword and sentiment analysis demonstrates the usefulness of the Twitter data, but also highlights that the actual number of Reef-related tweets is comparatively small and lacks specificity. Suggestions for further steps towards the development of an integrative data platform that incorporates social media are provided. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Carbon Flux Through the Giant Barrel Sponge Xestospongia testudinaria in the Red Sea

    KAUST Repository

    Wooster, Michael K.

    2017-11-01

    Sponges have important ecological functions on coral reefs because they are regionally abundant, competitively dominant, and process large volumes of seawater. The sponge loop hypothesis proposes that sponges consume dissolved organic carbon (DOC) and then releases the carbon as shed cellular detritus back to the reef benthos. Within this context, we examined the carbon flux mediated by the giant barrel sponge, Xestospongia testudinaria, on reefs in the Red Sea, where sponge abundance is comparatively low relative to coral reefs elsewhere, such as the Caribbean. Seawater samples were collected from the incurrent and excurrent (In-Ex) flow of 40 sponges from inshore, mid-shelf, and offshore reefs between 18° and 22°N latitude off the coast of Saudi Arabia. Concentrations of DOC and living particulate organic carbon (LPOC) were significantly higher in incurrent (ambient) seawater on inshore reefs than mid-shelf and offshore reefs. Consistent with studies of X. muta in the Caribbean, the diet of X. testudinaria is comprised primarily of DOC; mean values of the nutritional components across all sites were 60.5% DOC, 35.7% detritus, and 3.8% LPOC. Taking into account the specific filtration rates of nutritional components and oxygen consumption of sponges across the inshore-offshore gradient, there is evidence (1) of a threshold concentration of DOC below which sponges cease to be net consumers of DOC, and (2) that sponges on offshore reefs are food-limited. Contrary to the sponge loop hypothesis, there was no evidence that X. testudinaria, returned DOC to the benthos in the form of detritus, but was, instead, a net consumer of detritus from the water column. Unlike the cryptic, interstitial sponges that were studied to advance the sponge-loop hypothesis, emergent sponges may have an alternate pathway for returning DOC to the benthos by converting it to sponge biomass rather than sponge detritus.

  14. Variation in the composition of corals, fishes, sponges, echinoderms, ascidians, molluscs, foraminifera and macroalgae across a pronounced in-to-offshore environmental gradient in the Jakarta Bay-Thousand Islands coral reef complex.

    Science.gov (United States)

    Cleary, D F R; Polónia, A R M; Renema, W; Hoeksema, B W; Rachello-Dolmen, P G; Moolenbeek, R G; Budiyanto, A; Yahmantoro; Tuti, Y; Giyanto; Draisma, S G A; Prud'homme van Reine, W F; Hariyanto, R; Gittenberger, A; Rikoh, M S; de Voogd, N J

    2016-09-30

    Substrate cover, water quality parameters and assemblages of corals, fishes, sponges, echinoderms, ascidians, molluscs, benthic foraminifera and macroalgae were sampled across a pronounced environmental gradient in the Jakarta Bay-Thousand Islands reef complex. Inshore sites mainly consisted of sand, rubble and turf algae with elevated temperature, dissolved oxygen, pH and chlorophyll concentrations and depauperate assemblages of all taxa. Live coral cover was very low inshore and mainly consisted of sparse massive coral heads and a few encrusting species. Faunal assemblages were more speciose and compositionally distinct mid- and offshore compared to inshore. There were, however, small-scale differences among taxa. Certain midshore sites, for example, housed assemblages resembling those typical of the inshore environment but this differed depending on the taxon. Substrate, water quality and spatial variables together explained from 31% (molluscs) to 72% (foraminifera) of the variation in composition. In general, satellite-derived parameters outperformed locally measured parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Excess seawater nutrients, enlarged algal symbiont densities and bleaching sensitive reef locations: 1. Identifying thresholds of concern for the Great Barrier Reef, Australia.

    Science.gov (United States)

    Wooldridge, Scott A

    2016-05-23

    Here, I contribute new insight into why excess seawater nutrients are an increasingly identified feature at reef locations that have low resistance to thermal stress. Specifically, I link this unfavourable synergism to the development of enlarged (suboptimal) zooxanthellae densities that paradoxically limit the capacity of the host coral to build tissue energy reserves needed to combat periods of stress. I explain how both theoretical predictions and field observations support the existence of species-specific 'optimal' zooxanthellae densities ~1.0-3.0×10 6 cellscm- 2 . For the central Great Barrier Reef (GBR), excess seawater nutrients that permit enlarged zooxanthellae densities beyond this optimum range are linked with seawater chlorophyll a>0.45μg·L -1 ; a eutrophication threshold previously shown to correlate with a significant loss in species for hard corals and phototrophic octocorals on the central GBR, and herein shown to correlate with enhanced bleaching sensitivity during the 1998 and 2002 mass bleaching events. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Do clouds save the great barrier reef? satellite imagery elucidates the cloud-SST relationship at the local scale.

    Directory of Open Access Journals (Sweden)

    Susannah M Leahy

    Full Text Available Evidence of global climate change and rising sea surface temperatures (SSTs is now well documented in the scientific literature. With corals already living close to their thermal maxima, increases in SSTs are of great concern for the survival of coral reefs. Cloud feedback processes may have the potential to constrain SSTs, serving to enforce an "ocean thermostat" and promoting the survival of coral reefs. In this study, it was hypothesized that cloud cover can affect summer SSTs in the tropics. Detailed direct and lagged relationships between cloud cover and SST across the central Great Barrier Reef (GBR shelf were investigated using data from satellite imagery and in situ temperature and light loggers during two relatively hot summers (2005 and 2006 and two relatively cool summers (2007 and 2008. Across all study summers and shelf positions, SSTs exhibited distinct drops during periods of high cloud cover, and conversely, SST increases during periods of low cloud cover, with a three-day temporal lag between a change in cloud cover and a subsequent change in SST. Cloud cover alone was responsible for up to 32.1% of the variation in SSTs three days later. The relationship was strongest in both El Niño (2005 and La Niña (2008 study summers and at the inner-shelf position in those summers. SST effects on subsequent cloud cover were weaker and more variable among study summers, with rising SSTs explaining up to 21.6% of the increase in cloud cover three days later. This work quantifies the often observed cloud cooling effect on coral reefs. It highlights the importance of incorporating local-scale processes into bleaching forecasting models, and encourages the use of remote sensing imagery to value-add to coral bleaching field studies and to more accurately predict risks to coral reefs.

  17. Early-phase dynamics in coral recovery following cyclone disturbance on the inshore Great Barrier Reef, Australia

    Science.gov (United States)

    Sato, Yui; Bell, Sara C.; Nichols, Cassandra; Fry, Kent; Menéndez, Patricia; Bourne, David G.

    2018-06-01

    Coral recovery (the restoration of abundance and composition of coral communities) after disturbance is a key process that determines the resilience of reef ecosystems. To understand the mechanisms underlying the recovery process of coral communities, colony abundance and size distribution were followed on reefs around Pelorus Island, located in the inshore central region of the Great Barrier Reef, following a severe tropical cyclone in 2011 that caused dramatic loss of coral communities. Permanent quadrats (600 m2) were monitored biannually between 2012 and 2016, and individual coral colonies were counted, sized and categorized into morphological types. The abundance of coral recruits and coral cover were also examined using permanent quadrats and random line intercept transects, respectively. The number of colonies in the smallest size class (4-10 cm) increased substantially during the study period, driving the recovery of coral populations. The total number of coral colonies 5 yr post-cyclone reached between 73 and 122% of pre-cyclone levels though coral cover remained between 16 and 31% of pre-cyclone levels, due to the dominance of small coral colonies in the recovering communities. Temporal transitions of coral demography (i.e., colony-size distributions) illustrated that the number of recently established coral populations overtook communities of surviving colonies. Coral recruits (coral recovery. A shift in morphological composition of coral communities was also observed, with the relative abundance of encrusting corals reduced post-cyclone in contrast to their dominance prior to the disturbance. This study identifies the fine-scale processes involved in the initial recovery of coral reefs, providing insights into the dynamics of coral demography that are essential for determining coral reef resilience following major disturbance.

  18. Interactions between a Trawl fishery and spatial closures for biodiversity conservation in the Great Barrier Reef World Heritage Area, Australia.

    Directory of Open Access Journals (Sweden)

    Alana Grech

    Full Text Available BACKGROUND: The Queensland East Coast Otter Trawl Fishery (ECOTF for penaeid shrimp fishes within Australia's Great Barrier Reef World Heritage Area (GBRWHA. The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation. New information from electronic vessel location monitoring systems (VMS provides an opportunity to review the interactions between the ECOTF and spatial closures for biodiversity conservation. METHODOLOGY AND RESULTS: We used fishing metrics and spatial information on the distribution of closures and modelled VMS data in a geographical information system (GIS to assess change in effort of the trawl fishery from 2001-2009 and to quantify the exposure of 70 reef, non-reef and deep water bioregions to trawl fishing. The number of trawlers and the number of days fished almost halved between 2001 and 2009 and new spatial closures introduced in 2004 reduced the area zoned available for trawl fishing by 33%. However, we found that there was only a relatively minor change in the spatial footprint of the fishery as a result of new spatial closures. Non-reef bioregions benefited the most from new spatial closures followed by deep and reef bioregions. CONCLUSIONS/SIGNIFICANCE: Although the catch of non target species remains an issue of concern for fisheries management, the small spatial footprint of the ECOTF relative to the size of the GBRWHA means that the impact on benthic habitats is likely to be negligible. The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas. This will provide protection for most benthic habitats without any further legislative or management intervention.

  19. Host-specific interactions with environmental factors shape the distribution of symbiodinium across the Great Barrier Reef.

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    Linda Tonk

    Full Text Available The endosymbiotic dinoflagellates (genus Symbiodinium within coral reef invertebrates are critical to the survival of the holobiont. The genetic variability of Symbiodinium may contribute to the tolerance of the symbiotic association to elevated sea surface temperatures (SST. To assess the importance of factors such as the local environment, host identity and biogeography in driving Symbiodinium distributions on reef-wide scales, data from studies on reef invertebrate-Symbiodinium associations from the Great Barrier Reef (GBR were compiled.The resulting database consisted of 3717 entries from 26 studies. It was used to explore ecological patterns such as host-specificity and environmental drivers structuring community complexity using a multi-scalar approach. The data was analyzed in several ways: (i frequently sampled host species were analyzed independently to investigate the influence of the environment on symbiont distributions, thereby excluding the influence of host specificity, (ii host species distributions across sites were added as an environmental variable to determine the contribution of host identity on symbiont distribution, and (iii data were pooled based on clade (broad genetic groups dividing the genus Symbiodinium to investigate factors driving Symbiodinium distributions using lower taxonomic resolution. The results indicated that host species identity plays a dominant role in determining the distribution of Symbiodinium and environmental variables shape distributions on a host species-specific level. SST derived variables (especially SSTstdev most often contributed to the selection of the best model. Clade level comparisons decreased the power of the predictive model indicating that it fails to incorporate the main drivers behind Symbiodinium distributions.Including the influence of different host species on Symbiodinium distributional patterns improves our understanding of the drivers behind the complexity of Symbiodinium

  20. Organic biomarkers to describe the major carbon inputs and cycling of organic matter in the central Great Barrier Reef region

    Science.gov (United States)

    Burns, Kathryn; Brinkman, Diane

    2011-06-01

    Controversy surrounds the sources and transport of land derived pollutants in the Great Barrier Reef ecosystem because there is insufficient knowledge of the mechanism of movement of organic contaminants and the cycling of organic matter in this dynamic system. Thus a sediment and sediment trap study was used to describe the composition of resuspended and surface sediments in the south central Great Barrier Reef and its lagoon. This region is characterised by strong tides (6-8 m at Mackay) and trade winds regularly about 15-20 knots. A series of organic biomarkers detailed the cyclical processes of sediment resuspension, recolonising with marine algae and bacteria, packaging into zooplankton faecal pellets and resettlement to sediments where the organics undergo further diagenesis. With each cycle the inshore sediments are diluted with CaCO 3 reef sediments and moved further offshore with the strong ebb tide currents. This results in transport of land derived materials offshore and little storage of organic materials in the lagoon or reef sediments. These processes were detailed by inorganic measurements such as %CaCO 3 and Al/Ca ratios, and by the compositions of hydrocarbon, sterol, alcohol, and fatty acid lipid fractions. Persistent contaminants such as coal dust from a coastal loading facility can be detected in high concentration inshore and decreasing out to the shelf break at 180 m approximately 40 nautical miles offshore. The normal processes would likely be amplified during cyclonic and other storms. The lipids show the sources of carbon to include diatoms and other phytoplankton, creanaerchaeota, sulfate reducing and other bacteria, land plants including mangrove leaves, plus coal dust and other petroleum contaminants.

  1. Social Resilience and Commercial Fishers' Responses to Management Changes in the Great Barrier Reef Marine Park

    Directory of Open Access Journals (Sweden)

    Stephen G. Sutton

    2012-09-01

    Full Text Available Understanding how social resilience influences resource users' responses to policy change is important for ensuring the sustainability of social-ecological systems and resource-dependent communities. We use the conceptualization and operationalization of social resilience proposed by Marshall and Marshall (2007 to investigate how resilience level influenced commercial fishers' perceptions about and adaptation to the 2004 rezoning of the Great Barrier Reef Marine Park. We conducted face-to-face interviews with 114 commercial and charter fishers to measure their social resilience level and their responses and adaptation strategies to the 2004 zoning plan. Fishers with higher resilience were more likely to believe that the zoning plan was necessary, more likely to be supportive of the plan, and more likely to have adapted their fishing business and fishing activity to the plan than were fishers with lower social resilience. High-resilience fishers were also less likely to perceive negative impacts of the plan on their fishing business, less likely to have negative attitudes toward the consultation process used to develop and implement the plan, and less likely to have applied for financial compensation under the structural adjustment program. Results confirm the utility of the social resilience construct for identifying fishers who are likely to be vulnerable to changes, and those who are struggling to cope with change events. We conclude that managing for social resilience in the GBR would aid in the design and implementation of policies that minimize the impacts on resource users and lead to more inclusive and sustainable management, but that further research is necessary to better understand social resilience, how it can be fostered and sustained, and how it can be effectively incorporated into management.

  2. Spatiotemporal patterns of coral disease prevalence on Heron Island, Great Barrier Reef, Australia

    Science.gov (United States)

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

    2010-12-01

    Despite increasing research effort on coral diseases, little is known about factors driving disease dynamics on the Great Barrier Reef (GBR). This is the first study to investigate the temporal patterns of coral disease prevalence and potential drivers of disease around Heron Island, in the southern Capricorn Bunker sector of the GBR. Surveys were conducted in two austral summers and three winters between November 2007 and August 2009 on six sites around the island. Six diseases were detected: brown band syndrome (BrB), growth anomalies (GA), ulcerative white spots (UWS), white syndrome (WS), skeletal eroding band disease (SEB) and black band disease (BBD). The lowest overall mean disease prevalence was 1.87 ± 0.75% (mean ± SE) in November 2007 and the highest 4.22 ± 1.72% in August 2008. There was evidence of seasonality for two diseases: BrB and UWS. This is the first study to report a higher prevalence of BrB in the winter. BrB had a prevalence of 3.29 ± 0.58% in August 2008 and 1.53 ± 0.28% in August 2009, while UWS was the most common syndrome in the summer with a prevalence of 1.12 ± 0.31% in November 2007 and 2.67 ± 0.52% prevalence in January 2008. The prevalence of GAs and SEB did not depend on the season, although the prevalence of GAs increased throughout the study period. WS had a slightly higher prevalence in the summer, but its overall prevalence was low (disease prevalence (12% of Acropora and 3.3% of Montipora species were diseased respectively). These results highlight the correlations between coral disease prevalence, seasonally varying environmental parameters and coral community composition. Given that diseases are likely to reduce the resilience of corals, seasonal patterns in disease prevalence deserve further research.

  3. Modelling the fate of marine debris along a complex shoreline: Lessons from the Great Barrier Reef

    Science.gov (United States)

    Critchell, K.; Grech, A.; Schlaefer, J.; Andutta, F. P.; Lambrechts, J.; Wolanski, E.; Hamann, M.

    2015-12-01

    The accumulation of floating anthropogenic debris in marine and coastal areas has environmental, economic, aesthetic, and human health impacts. Until now, modelling the transport of such debris has largely been restricted to the large-scales of open seas. We used oceanographic modelling to identify potential sites of debris accumulation along a rugged coastline with headlands, islands, rocky coasts and beaches. Our study site was the Great Barrier Reef World Heritage Area that has an emerging problem with debris accumulation. We found that the classical techniques of modelling the transport of floating debris models are only moderately successful due to a number of unknowns or assumptions, such as the value of the wind drift coefficient, the variability of the oceanic forcing and of the wind, the resuspension of some floating debris by waves, and the poorly known relative contribution of floating debris from urban rivers and commercial and recreational shipping. Nevertheless the model was successful in reproducing a number of observations such as the existence of hot spots of accumulation. The orientation of beaches to the prevailing wind direction affected the accumulation rate of debris. The wind drift coefficient and the exact timing of the release of the debris at sea affected little the movement of debris originating from rivers but it affected measurably that of debris originating from ships. It was thus possible to produce local hotspot maps for floating debris, especially those originating from rivers. Such modelling can be used to inform local management decisions, and it also identifies likely priority research areas to more reliably predict the trajectory and landing points of floating debris.

  4. Characterizing the sponge grounds of Grays Canyon, Washington, USA

    Science.gov (United States)

    Powell, Abby N.; Clarke, M. Elizabeth; Fruh, Erica; Chaytor, Jason; Reiswig, Henry M.; Whitmire, Curt E.

    2018-01-01

    Deep-sea sponge grounds are relatively understudied ecosystems that may provide key habitats for a large number of fish and invertebrates including commercial species. Glass sponge grounds have been discovered from the tropics to polar regions but there are only a few places with high densities of dictyonine sponges. Dictyonine glass sponges have a fused skeleton, which stays intact when they die and in some areas the accumulation of successive generations of sponges leads to the formation of reefs. In 2010 and 2016, we surveyed an area near Grays Canyon in Washington, USA, where dense aggregations of glass sponges and potential sponge reefs were discovered in 2007. Our primary aims were to make a preliminary assessment of whether the glass sponges form reefs at this location, characterize the sponge assemblage present at this site and examine associations between the sponges and commercially important species. Multibeam mapping and sub-bottom profiling indicate that the glass sponges at this site do not form reefs and are mostly attached to hard substrates. Analysis of photographs collected by an autonomous underwater vehicle and samples collected by a remotely operated vehicle guided by telepresence revealed the presence of two abundant dictyonine sponge species at this site, Heterochone calyx and Aphrocallistes vastus (mean densities = 1.43 ± 0.057 per 10 m2, max = 24 per 10 m2). We also observed a large number of non-reef-building glass sponges and various demosponges including a potentially new species in the genus Acarnus. A diverse fish assemblage was recorded at this site including eight species of rockfish. Rockfish abundance was positively related to sponge abundance. Spot prawns (Pandalus platyceros) were also abundant and were strongly associated with sponges. Despite not finding sponge reefs, this is an ecologically significant area. Further research is necessary to determine the environmental factors that give rise to the abundance of large

  5. The importance of coastal altimetry retracking and detiding: A case study around the Great Barrier Reef, Australia

    DEFF Research Database (Denmark)

    Idris, Nurul H.; Deng, Xiaoli; Andersen, Ole Baltazar

    2014-01-01

    , fuzzy-retracked SLAs become available within 5 km of the coast; meanwhile it becomes more important to use pointwise tide modelling rather than state-of-the-art global tidal models, as the latter leave residual ocean tide signals in retracked SLAs. These improvements are demonstrated for Jason-2...... waveforms in the area of the Great Barrier Reef, Australia. Comparing the retrieved SLAs with in situ tide gauge data from Townsville and Bundaberg stations showed that the SLAs from this study generally outperform those from conventional methods, demonstrating that adequate waveform retracking and detiding...

  6. Nitrification in reef corals

    Digital Repository Service at National Institute of Oceanography (India)

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

    . An estimate of the density of nitrifying bacteria on living corals can be made by comparing the nitrifying rates of bacterial cells and the rate of production of NO,-. Kaplan (1983) summarized the growth con- stants of marine nitrifying bacteria... Reef Con=. 3: 395-399. -, C. R. WILKINSON, V. p. VICENTE, J. M. MORELL, AND E. OTERO. 1988. Nitrate release by Carib- bean reef sponges. Limnol. Oceanogr. 33: 114- 120. CROSSLAND, C. J., AND D. J. BARNES. 1983. Dissolved nutrients and organic...

  7. Diversity and abundance of photosynthetic sponges in temperate Western Australia

    Directory of Open Access Journals (Sweden)

    Brümmer Franz

    2009-02-01

    Full Text Available Abstract Background Photosynthetic sponges are important components of reef ecosystems around the world, but are poorly understood. It is often assumed that temperate regions have low diversity and abundance of photosynthetic sponges, but to date no studies have investigated this question. The aim of this study was to compare the percentages of photosynthetic sponges in temperate Western Australia (WA with previously published data on tropical regions, and to determine the abundance and diversity of these associations in a range of temperate environments. Results We sampled sponges on 5 m belt transects to determine the percentage of photosynthetic sponges and identified at least one representative of each group of symbionts using 16S rDNA sequencing together with microscopy techniques. Our results demonstrate that photosynthetic sponges are abundant in temperate WA, with an average of 63% of sponge individuals hosting high levels of photosynthetic symbionts and 11% with low to medium levels. These percentages of photosynthetic sponges are comparable to those found on tropical reefs and may have important implications for ecosystem function on temperate reefs in other areas of the world. A diverse range of symbionts sometimes occurred within a small geographic area, including the three "big" cyanobacterial clades, Oscillatoria spongeliae, "Candidatus Synechococcus spongiarum" and Synechocystis species, and it appears that these clades all occur in a wide range of sponges. Additionally, spongin-permeating red algae occurred in at least 7 sponge species. This study provides the first investigation of the molecular phylogeny of rhodophyte symbionts in sponges. Conclusion Photosynthetic sponges are abundant and diverse in temperate WA, with comparable percentages of photosynthetic to non-photosynthetic sponges to tropical zones. It appears that there are three common generalist clades of cyanobacterial symbionts of sponges which occur in a wide

  8. A new gnathiid (Crustacea: Isopoda) parasitizing two species of requiem sharks from Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Coetzee, Maryke L; Smit, Nico J; Grutter, Alexandra S; Davies, Angela J

    2008-06-01

    Third-stage juveniles (praniza 3) of Gnathia grandilaris n. sp. were collected from the gill filaments and septa of 5 requiem sharks, including a white tip reef shark, Triaenodon obesus, and 4 grey reef sharks, Carcharhinus amblyrhynchos, at Lizard Island, Great Barrier Reef, Australia, in March 2002. Some juvenile gnathiids were then maintained in fresh sea water until they molted to adults. Adult males appeared 19 days following detachment of juveniles from host fishes, but no juveniles molted successfully into females. The current description is based, therefore, on bright field and scanning electron microscopy observations of adult males and third-stage juveniles. Unique features of the male include the triangular-shaped inferior medio-frontal process, 2 areolae on the dorsal surface of the pylopod, and a slender pleotelson (twice as long as wide) with lateral concavities. The third-stage juvenile has distinctive white pigmentation on the black pereon when alive, while the mandible has 9 triangular backwardly directed teeth. This species has the largest male and third-stage juvenile of any Gnathia spp. from Australia and of any gnathiid isopods associated with elasmobranchs.

  9. The relative abundance of dimethylsulfoniopropionate (DMSP) among other zwitterions in branching coral at Heron Island, southern Great Barrier Reef.

    Science.gov (United States)

    Swan, Hilton B; Deschaseaux, Elisabeth S M; Jones, Graham B; Eyre, Bradley D

    2017-07-01

    Dimethylsulfoniopropionate (DMSP) and eleven other target zwitterions were quantified in the branch tips of six Acropora species and Stylophora pistillata hard coral growing on the reef flat surrounding Heron Island in the southern Great Barrier Reef (GBR), Australia. Hydrophilic interaction liquid chromatography mass spectrometry (HILIC-MS) was used for sample analysis with isotope dilution MS applied to quantify DMSP. The concentration of DMSP was ten times greater in A. aspera than A. valida, with this difference being maintained throughout the spring, summer and winter seasons. In contrast, glycine betaine was present in significantly higher concentrations in these species during the summer than the winter. Exposure of branch tips of A. aspera to air and hypo-saline seawater for up to 1 h did not alter the concentrations of DMSP present in the coral when compared with control samples. DMSP was the most abundant target zwitterion in the six Acropora species examined, ranging from 44-78% of all target zwitterions in A. millepora and A. aspera, respectively. In contrast, DMSP only accounted for 7% in S. pistillata, with glycine betaine and stachydrine collectively accounting for 88% of all target zwitterions in this species. The abundance of DMSP in the six Acropora species examined points to Acropora coral being an important source for the biogeochemical cycling of sulfur throughout the GBR, since this reef-building branching coral dominates the coral cover of the GBR. Graphical Abstract HILIC-MS extracted ion chromatogram showing zwitterionic metabolites from the branching coral Acropora isopora.

  10. Flood impacts in Keppel Bay, southern great barrier reef in the aftermath of cyclonic rainfall.

    Directory of Open Access Journals (Sweden)

    Alison M Jones

    Full Text Available In December 2010, the highest recorded Queensland rainfall associated with Tropical Cyclone 'Tasha' caused flooding of the Fitzroy River in Queensland, Australia. A massive flood plume inundated coral reefs lying 12 km offshore of the Central Queensland coast near Yeppoon and caused 40-100% mortality to coral fringing many of the islands of Keppel Bay down to a depth of ∼8 m. The severity of coral mortality was influenced by the level of exposure to low salinity seawater as a result of the reef's distance from the flood plume and to a lesser extent, water depth and whether or not the reef faced the plume source. There was no evidence in this study of mortality resulting from pollutants derived from the nearby Fitzroy Catchment, at least in the short term, suggesting that during a major flood, the impact of low salinity on corals outweighs that of pollutants. Recovery of the reefs in Keppel Bay from the 2010/2011 Fitzroy River flood is likely to take 10-15 years based on historical recovery periods from a similar event in 1991; potentially impacting visitor numbers for tourism and recreational usage. In the meantime, activities like snorkeling, diving and coral viewing will be focused on the few shallow reefs that survived the flood, placing even further pressure on their recovery. Reef regeneration, restoration and rehabilitation are measures that may be needed to support tourism in the short term. However, predictions of a warming climate, lower rainfall and higher intensity summer rain events in the Central and Coastal regions of Australia over the next decade, combined with the current anthropogenic influences on water quality, are likely to slow regeneration with consequent impact on long-term reef resilience.

  11. The bioeroding sponge Cliona orientalis will not tolerate future projected ocean warming.

    Science.gov (United States)

    Ramsby, Blake D; Hoogenboom, Mia O; Smith, Hillary A; Whalan, Steve; Webster, Nicole S

    2018-05-29

    Coral reefs face many stressors associated with global climate change, including increasing sea surface temperature and ocean acidification. Excavating sponges, such as Cliona spp., are expected to break down reef substrata more quickly as seawater becomes more acidic. However, increased bioerosion requires that Cliona spp. maintain physiological performance and health under continuing ocean warming. In this study, we exposed C. orientalis to temperature increments increasing from 23 to 32 °C. At 32 °C, or 3 °C above the maximum monthly mean (MMM) temperature, sponges bleached and the photosynthetic capacity of Symbiodinium was compromised, consistent with sympatric corals. Cliona orientalis demonstrated little capacity to recover from thermal stress, remaining bleached with reduced Symbiodinium density and energy reserves after one month at reduced temperature. In comparison, C. orientalis was not observed to bleach during the 2017 coral bleaching event on the Great Barrier Reef, when temperatures did not reach the 32 °C threshold. While C. orientalis can withstand current temperature extremes (<3 °C above MMM) under laboratory and natural conditions, this species would not survive ocean temperatures projected for 2100 without acclimatisation or adaptation (≥3 °C above MMM). Hence, as ocean temperatures increase above local thermal thresholds, C. orientalis will have a negligible impact on reef erosion.

  12. The Gulf of Carpentaria heated Torres Strait and the Northern Great Barrier Reef during the 2016 mass coral bleaching event

    Science.gov (United States)

    Wolanski, E.; Andutta, F.; Deleersnijder, E.; Li, Y.; Thomas, C. J.

    2017-07-01

    The 2015/16 ENSO event increased the temperature of waters surrounding northeast Australia to above 30 °C, with large patches of water reaching 32 °C, for over two months, which led to severe bleaching of corals of the Northern Great Barrier Reef (NGBR). This study provides evidence gained from remote-sensing data, oceanographic data and oceanographic modeling, that three factors caused this excessive heating, namely: 1) the shutdown of the North Queensland Coastal Current, which would otherwise have flushed and cooled the Northern Coral Sea and the NGBR through tidal mixing 2) the advection of warm (>30 °C) water from the Gulf of Carpentaria eastward through Torres Strait and then southward over the NGBR continental shelf, and 3) presumably local solar heating. The eastward flux of this warm water through Torres Strait was driven by a mean sea level difference on either side of the strait that in turn was controlled by the wind, which also generated the southward advection of this warm water onto the NGBR shelf. On the NGBR shelf, the residence time of this warm water was longer inshore than offshore, and this may explain the observed cross-shelf gradient of coral bleaching intensity. The fate of the Great Barrier Reef is thus controlled by the oceanography of surrounding seas.

  13. Degradation of mangrove-derived organic matter in mangrove associated sponges

    NARCIS (Netherlands)

    Hunting, E.R.; de Goeij, J.M.; Asselman, M.; van Soest, R.W.M.; van der Geest, H.G.

    2010-01-01

    Sponge communities found in Caribbean mangroves are typical to this habitat: partly endemic and very distinct from sponge communities on nearby reefs. A trade-off between resistance to competitors and predators appears to influence success of individual sponge species in mangrove habitats. We

  14. Tetractinellid and hadromerid sponges of the Sultanate of Oman

    NARCIS (Netherlands)

    Soest, van R.W.M.; Beglinger, E.J.

    2008-01-01

    The Sultanate of Oman harbours rich populations of sponges, especially in the four coral reef areas (Musandam Peninsula, Muscat coast & Daymaniyat islands, coasts of Masirah Island, and the Khuriya Muriya Islands). Up till now, apart from a few incidental samples, the sponges of Oman were known only

  15. Differences in demographic traits of four butterflyfish species between two reefs of the Great Barrier Reef separated by 1,200 km

    KAUST Repository

    Berumen, Michael L.

    2011-11-16

    Many species demonstrate variation in life history attributes in response to gradients in environmental conditions. For fishes, major drivers of life history variation are changes in temperature and food availability. This study examined large-scale variation in the demography of four species of butterflyfishes (Chaetodon citrinellus, Chaetodon lunulatus, Chaetodon melannotus, and Chaetodon trifascialis) between two locations on Australia\\'s Great Barrier Reef (Lizard Island and One Tree Island, separated by approximately 1,200 km). Variation in age-based demographic parameters was assessed using the re-parameterised von Bertalanffy growth function. All species displayed measurable differences in body size between locations, with individuals achieving a larger adult size at the higher latitude site (One Tree Island) for three of the four species examined. Resources and abundances of the study species were also measured, revealing some significant differences between locations. For example, for C. trifascialis, there was no difference in its preferred resource or in abundance between locations, yet it achieved a larger body size at the higher latitude location, suggesting a response to temperature. For some species, resources and abundances did vary between locations, limiting the ability to distinguish between a demographic response to temperature as opposed to a response to food or competition. Future studies of life histories and demographics at large spatial scales will need to consider the potentially confounding roles of temperature, resource usage and availability, and abundance/competition to disentangle the effects of these environmental variables. © 2011 Springer-Verlag.

  16. Origins and Implications of a Primary Crown-of-Thorns Starfish Outbreak in the Southern Great Barrier Reef

    Directory of Open Access Journals (Sweden)

    Ian Miller

    2015-01-01

    Full Text Available The crown-of-thorns starfish (COTS is a major predator of hard corals. Repeated COTS outbreaks in the Cairns and Central sections of the Great Barrier Reef (GBR have been responsible for greater declines in coral cover than any other type of disturbance, including cyclones, disease, and coral bleaching. Knowledge of the precise timing and location of primary outbreaks could reveal the initial drivers of outbreaks and so could indicate possible management measures. In the central GBR, COTS outbreaks appear to follow major flooding events, but despite many years of observations, no primary outbreak has ever been unequivocally identified in the central and northern GBR. Here we locate a primary outbreak of COTS on the southern GBR which is not correlated with flooding. Instead it appears to have been the result of a combination of life history traits of COTS and prevailing oceanographic conditions. The hydrodynamic setting implies that the outbreak could disperse larvae to other reefs in the region.

  17. Regional-scale variation in the distribution and abundance of farming damselfishes on Australia's Great Barrier Reef

    KAUST Repository

    Emslie, Michael J.

    2012-03-15

    Territorial damselfishes that manipulate ("farm") the algae in their territories can have a marked effect on benthic community structure and may influence coral recovery following disturbances. Despite the numerical dominance of farming species on many reefs, the importance of their grazing activities is often overlooked, with most studies only examining their roles over restricted spatial and temporal scales. We used the results of field surveys covering 9.5° of latitude of the Great Barrier Reef to describe the distribution, abundance and temporal dynamics of farmer communities. Redundancy analysis revealed unique subregional assemblages of farming species that were shaped by the combined effects of shelf position and, to a lesser extent, by latitude. These spatial patterns were largely stable through time, except when major disturbances altered the benthic community. Such disturbances affected the functional guilds of farmers in different ways. Since different guilds of farmers modify benthic community structure and affect survival of juvenile corals in different ways, these results have important implications for coral recovery following disturbances. © 2012 Springer-Verlag.

  18. Regional-scale variation in the distribution and abundance of farming damselfishes on Australia's Great Barrier Reef

    KAUST Repository

    Emslie, Michael J.; Logan, Murray; Ceccarelli, Daniela M.; Cheal, Alistair J.; Hoey, Andrew; Miller, Ian R.; Sweatman, Hugh P A

    2012-01-01

    Territorial damselfishes that manipulate ("farm") the algae in their territories can have a marked effect on benthic community structure and may influence coral recovery following disturbances. Despite the numerical dominance of farming species on many reefs, the importance of their grazing activities is often overlooked, with most studies only examining their roles over restricted spatial and temporal scales. We used the results of field surveys covering 9.5° of latitude of the Great Barrier Reef to describe the distribution, abundance and temporal dynamics of farmer communities. Redundancy analysis revealed unique subregional assemblages of farming species that were shaped by the combined effects of shelf position and, to a lesser extent, by latitude. These spatial patterns were largely stable through time, except when major disturbances altered the benthic community. Such disturbances affected the functional guilds of farmers in different ways. Since different guilds of farmers modify benthic community structure and affect survival of juvenile corals in different ways, these results have important implications for coral recovery following disturbances. © 2012 Springer-Verlag.

  19. A multi-criteria approach to Great Barrier Reef catchment (Queensland, Australia) diffuse-source pollution problem.

    Science.gov (United States)

    Greiner, R; Herr, A; Brodie, J; Haynes, D

    2005-01-01

    This paper presents a multi-criteria based tool for assessing the relative impact of diffuse-source pollution to the Great Barrier Reef (GBR) from the river basins draining into the GBR lagoon. The assessment integrates biophysical and ecological data of water quality and pollutant concentrations with socio-economic information pertaining to non-point source pollution and (potential) pollutant impact. The tool generates scores for each river basin against four criteria, thus profiling the basins and enabling prioritization of management alternatives between and within basins. The results support policy development for pollution control through community participation, scientific data integration and expert knowledge contributed by people from across the catchment. The results specifically provided support for the Reef Water Quality Protection Plan, released in October 2003. The aim of the plan is to provide a framework for reducing discharge of sediment, nutrient and other diffuse-source loads and (potential) impact of that discharge and for prioritising management actions both between and within river basins.

  20. Future Scenarios as a Research Tool: Investigating Climate Change Impacts, Adaptation Options and Outcomes for the Great Barrier Reef, Australia.

    Science.gov (United States)

    Evans, Louisa S; Hicks, Christina C; Fidelman, Pedro; Tobin, Renae C; Perry, Allison L

    2013-01-01

    Climate change is a significant future driver of change in coastal social-ecological systems. Our knowledge of impacts, adaptation options, and possible outcomes for marine environments and coastal industries is expanding, but remains limited and uncertain. Alternative scenarios are a way to explore potential futures under a range of conditions. We developed four alternative future scenarios for the Great Barrier Reef and its fishing and tourism industries positing moderate and more extreme (2-3 °C above pre-industrial temperatures) warming for 2050 and contrasting 'limited' and 'ideal' ecological and social adaptation. We presented these scenarios to representatives of key stakeholder groups to assess the perceived viability of different social adaptation options to deliver desirable outcomes under varied contexts.

  1. Inferring coastal processes from regional-scale mapping of 222Radon and salinity: examples from the Great Barrier Reef, Australia

    International Nuclear Information System (INIS)

    Stieglitz, Thomas C.; Cook, Peter G.; Burnett, William C.

    2010-01-01

    The radon isotope 222 Rn and salinity in coastal surface water were mapped on regional scales, to improve the understanding of coastal processes and their spatial variability. Radon was measured with a surface-towed, continuously recording multi-detector setup on a moving vessel. Numerous processes and locations of land-ocean interaction along the Central Great Barrier Reef coastline were identified and interpreted based on the data collected. These included riverine fluxes, terrestrially-derived fresh submarine groundwater discharge (SGD) and the tidal pumping of seawater through mangrove forests. Based on variations in the relationship of the tracers radon and salinity, some aspects of regional freshwater inputs to the coastal zone and to estuaries could be assessed. Concurrent mapping of radon and salinity allowed an efficient qualitative assessment of land-ocean interaction on various spatial and temporal scales, indicating that such surveys on coastal scales can be a useful tool to obtain an overview of SGD locations and processes.

  2. The ugly face of tourism: Marine debris pollution linked to visitation in the southern Great Barrier Reef, Australia.

    Science.gov (United States)

    Wilson, Scott P; Verlis, Krista M

    2017-04-15

    Marine debris is one of the most significant issues facing oceans worldwide. The sources of this debris vary depending on proximity to urban centres and the nature of activities within an area. This paper examines the influence of tourism in the southern Great Barrier Reef (GBR), and its contribution to litter levels in the region. By conducting beach debris surveys on occupied and unoccupied islands, this study found that debris was prevalent throughout the region with significant differences in material types between locations. The greatest source of debris from publically accessible islands was tourist-related, with this source also influencing debris loads on nearby uninhabited islands. A focus on debris at Heron Island, showed that sites close to amenities had greater levels of tourist-sourced items like cigarette butts. These findings indicate the contribution of tourists to this problem and that working with operators and managers is needed to minimise visitor impacts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effects of warming, acidification, and reef-zone on the calcification of four Caribbean scleractinian corals of the Belize Barrier Reef System

    Science.gov (United States)

    Bove, C. B.; Ries, J. B.; Davies, S. W.; Westfield, I. T.; Castillo, K.

    2016-02-01

    Rising atmospheric carbon dioxide (pCO2) has caused ocean temperature to increase and ocean pH to decrease, raising concerns about the health of marine organisms. Previous studies have shown that corals are particularly vulnerable to these stressors, most likely due to their narrow thermal tolerance and use of carbonate ions in calcification, although response patterns vary across taxa. We conducted laboratory experiments for 95 days to investigate the independent and interactive effects of ocean warming (28, 31 °C) and acidification on the calcification rate and skeletal properties of four abundant and ubiquitously distributed Caribbean coral species (Pseudodiploria strigosa, Siderastrea siderea, Porites astreoides, Undaria tenuifolia) collected from nearshore and forereef environments of the Belize Barrier Reef. Aragonite saturation states of 3.9, 3.2, 2.2, and 0.7, constrained by total alkalinity measured via closed-cell potentiometric titration and dissolved inorganic carbon measured via coulometry, were attained by sparging natural seawater with air-CO2 mixtures formulated at 280, 400, 700, and 2800 ppmv pCO2, respectively. Temperature and pCO2 were fully crossed (N=3 tanks per treatment) and corals were gradually exposed to treatment conditions over a 30-day period, followed by an additional 30-day acclimation. Rates of linear skeletal extension were measured relative to a calcein spike emplaced in the coral skeletons at the start of the experiment, and net calcification rates were determined from coral buoyant weights obtained every 30 days. Initial results show that corals in all treatments continued to calcify on a net basis, however, the effect of warming on net calcification rates of P. asteroids and U. tenuifolia became more negative at lower saturation states. In addition, nearshore U. tenuifolia calcified faster than forereef conspecifics in all treatments.

  4. The Açu Reef morphology, distribution, and inter reef sedimentation on the outer shelf of the NE Brazil equatorial margin

    Science.gov (United States)

    do Nascimento Silva, Luzia Liniane; Gomes, Moab Praxedes; Vital, Helenice

    2018-05-01

    Submerged reefs, referred to as the Açu Reefs, have been newly observed on both sides of the Açu Incised Valley on the northeastern equatorial Brazilian outer shelf. This study aims to understand the roles of shelf physiography, its antecedent morphologies, and its inter reef sedimentation on the different development stages of the biogenic reef during last deglacial sea-level rise. The data sets consist of side-scan sonar imagery, one sparker seismic profile, 76 sediment samples, and underwater photography. Seven backscatter patterns (P1 to P7) were identified and associated with eleven sedimentary carbonate and siliciclastic facies. The inherited relief, the mouth of the paleo incised valley, and the interreef sediment distribution play major controls on the deglacial reef evolution. The reefs occur in a depth-limited 25-55 m water depth range and in a 6 km wide narrow zone of the outer shelf. The reefs crop out in a surface area over 100 km2 and occur as a series of NW-SE preferentially orientated ridges composed of three parallel ridge sets at 45, 35, and 25 m of water depth. The reefs form a series of individual, roughly linear ridges, tens of km in length, acting as barriers in addition to scattered reef mounds or knolls, averaging 4 m in height and grouped in small patches and aggregates. The reefs, currently limited at the transition between the photic and mesophotic zones, are thinly covered by red algae and scattered coral heads and sponges. Taking into account the established sea-level curves from the equatorial Brazilian northeastern shelf / Rochas Atoll and Barbados, the shelf physiography, and the shallow bedrock, the optimal conditions for reef development had to occur during a time interval (11-9 kyr BP) characterized by a slowdown of the outer shelf flooding, immediately following Meltwater Pulse-1B. This 2 kyr short interval provided unique conditions for remarkable reef backstepping into distinct parallel ridge sets. Furthermore, the Açu Reefs

  5. Variation in the health and biochemical condition of the coral Acropora tenuis along two water quality gradients on the Great Barrier Reef, Australia.

    Science.gov (United States)

    Rocker, Melissa M; Francis, David S; Fabricius, Katharina E; Willis, Bette L; Bay, Line K

    2017-06-30

    This study explores how plasticity in biochemical attributes, used as indicators of health and condition, enables the coral Acropora tenuis to respond to differing water quality regimes in inshore regions of the Great Barrier Reef. Health attributes were monitored along a strong and weak water quality gradient, each with three reefs at increasing distances from a major river source. Attributes differed significantly only along the strong gradient; corals grew fastest, had the least dense skeletons, highest symbiont densities and highest lipid concentrations closest to the river mouth, where water quality was poorest. High nutrient and particulate loads were only detrimental to skeletal density, which decreased as linear extension increased, highlighting a trade-off. Our study underscores the importance of assessing multiple health attributes in coral reef monitoring. For example, autotrophic indices are poor indicators of coral health and condition, but improve when combined with attributes like lipid content and biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Chimerism in wild adult populations of the broadcast spawning coral Acropora millepora on the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Eneour Puill-Stephan

    2009-11-01

    Full Text Available Chimeras are organisms containing tissues or cells of two or more genetically distinct individuals, and are known to exist in at least nine phyla of protists, plants, and animals. Although widespread and common in marine invertebrates, the extent of chimerism in wild populations of reef corals is unknown.The extent of chimerism was explored within two populations of a common coral, Acropora millepora, on the Great Barrier Reef, Australia, by using up to 12 polymorphic DNA microsatellite loci. At least 2% and 5% of Magnetic Island and Pelorus Island populations of A. millepora, respectively, were found to be chimeras (3% overall, based on conservative estimates. A slightly less conservative estimate indicated that 5% of colonies in each population were chimeras. These values are likely to be vast underestimates of the true extent of chimerism, as our sampling protocol was restricted to a maximum of eight branches per colony, while most colonies consist of hundreds of branches. Genotypes within chimeric corals showed high relatedness, indicating that genetic similarity is a prerequisite for long-term acceptance of non-self genotypes within coral colonies.While some brooding corals have been shown to form genetic chimeras in their early life history stages under experimental conditions, this study provides the first genetic evidence of the occurrence of coral chimeras in the wild and of chimerism in a broadcast spawning species. We hypothesize that chimerism is more widespread in corals than previously thought, and suggest that this has important implications for their resilience, potentially enhancing their capacity to compete for space and respond to stressors such as pathogen infection.

  7. Epizoic zoanthids reduce pumping in two Caribbean vase sponges

    Science.gov (United States)

    Lewis, T. B.; Finelli, C. M.

    2015-03-01

    Sponges are common sessile benthic suspension feeders that play a critical role in carbon and nitrogen cycling within reef ecosystems via their filtration capabilities. Due to the contribution of sponges in benthic-pelagic coupling, it is critical to assess factors that may affect their role in the healthy function of coral reefs. Several factors can influence the rate at which an individual sponge pumps water, including body size, environmental conditions, mechanical blockage, and reduction of inhalant pores (ostia). Symbiotic zoanthid colonization is a common occurrence on Caribbean sponges, and the presence of zoanthids on the surface of a sponge may occlude or displace the inhalant ostia. We quantified pumping rates of the giant barrel sponge, Xestospongia muta ( N = 22 uncolonized, 37 colonized) and the common vase sponge, Niphates digitalis ( N = 21 uncolonized, 17 colonized), with and without zoanthid symbionts, Parazoanthus catenularis and Parazoanthus parasiticus, respectively. For X. muta, biovolume-normalized pumping rates of individuals colonized by zoanthids were approximately 75 % lower than those of uncolonized sponges. Moreover, colonization with zoanthids was related to a difference in morphology relative to uncolonized individuals: Colonized sponges exhibited an osculum area to biovolume ratio that was nearly 65 % less than uncolonized sponges. In contrast, the presence of zoanthids on N. digitalis resulted in only a marginal decrease in pumping rates and no detectable difference in morphology. The difference in zoanthid effects between X. muta and N. digitalis is likely due to the differences in wall thickness and architecture between the two species. The probable cause of reduced pumping in affected sponges is occupation of the sponge surface that leads to blockage or displacement of inhalant ostia. To partially test this hypothesis, zoanthid colonization on specimens of X. muta was simulated by wrapping sponges with plastic mesh of varying

  8. Cell kinetics during regeneration in the sponge Halisarca caerulea: how local is the response to tissue damage?

    NARCIS (Netherlands)

    Alexander, B.E.; Achlatis, M.; Osinga, R.; van der Geest, H.G.; Cleutjens, J.P.M.; Schutte, B.; de Goeij, J.M.

    2015-01-01

    Sponges have a remarkable capacity to rapidly regenerate in response to wound infliction. In addition, sponges rapidly renew their filter systems (choanocytes) to maintain a healthy population of cells. This study describes the cell kinetics of choanocytes in the encrusting reef sponge Halisarca

  9. Two distinct microbial communities revealed in the sponge Cinachyrella

    Science.gov (United States)

    Cuvelier, Marie L.; Blake, Emily; Mulheron, Rebecca; McCarthy, Peter J.; Blackwelder, Patricia; Thurber, Rebecca L. Vega; Lopez, Jose V.

    2014-01-01

    Marine sponges are vital components of benthic and coral reef ecosystems, providing shelter and nutrition for many organisms. In addition, sponges act as an essential carbon and nutrient link between the pelagic and benthic environment by filtering large quantities of seawater. Many sponge species harbor a diverse microbial community (including Archaea, Bacteria and Eukaryotes), which can constitute up to 50% of the sponge biomass. Sponges of the genus Cinachyrella are common in Caribbean and Floridian reefs and their archaeal and bacterial microbiomes were explored here using 16S rRNA gene tag pyrosequencing. Cinachyrella specimens and seawater samples were collected from the same South Florida reef at two different times of year. In total, 639 OTUs (12 archaeal and 627 bacterial) belonging to 2 archaeal and 21 bacterial phyla were detected in the sponges. Based on their microbiomes, the six sponge samples formed two distinct groups, namely sponge group 1 (SG1) with lower diversity (Shannon-Weiner index: 3.73 ± 0.22) and SG2 with higher diversity (Shannon-Weiner index: 5.95 ± 0.25). Hosts' 28S rRNA gene sequences further confirmed that the sponge specimens were composed of two taxa closely related to Cinachyrella kuekenthalli. Both sponge groups were dominated by Proteobacteria, but Alphaproteobacteria were significantly more abundant in SG1. SG2 harbored many bacterial phyla (>1% of sequences) present in low abundance or below detection limits (<0.07%) in SG1 including: Acidobacteria, Chloroflexi, Gemmatimonadetes, Nitrospirae, PAUC34f, Poribacteria, and Verrucomicrobia. Furthermore, SG1 and SG2 only had 95 OTUs in common, representing 30.5 and 22.4% of SG1 and SG2's total OTUs, respectively. These results suggest that the sponge host may exert a pivotal influence on the nature and structure of the microbial community and may only be marginally affected by external environment parameters. PMID:25408689

  10. Two distinct microbial communities revealed in the sponge Cinachyrella

    Directory of Open Access Journals (Sweden)

    Marie Laure Cuvelier

    2014-11-01

    Full Text Available Marine sponges are vital components of benthic and coral reef ecosystems, providing shelter and nutrition for many organisms. In addition, sponges act as an essential carbon and nutrient link between the pelagic and benthic environment by filtering large quantities of seawater. Many sponge species harbor a diverse microbial community (including Archaea, Bacteria and Eukaryotes, which can constitute up to 50% of the sponge biomass. Sponges of the genus Cinachyrella are common in Caribbean and Floridian reefs and their archaeal and bacterial microbiomes were explored here using 16S rDNA tag pyrosequencing. Cinachyrella specimens and seawater samples were collected from the same South Florida reef at two different times of year. In total, 639 OTUs (12 archaeal and 627 bacterial belonging to 2 archaeal and 21 bacterial phyla were detected in the sponges. Based on their microbiomes, the six sponge samples formed two distinct groups, namely sponge group 1 (SG1 with low diversity (Shannon-Weiner index: 3.73 ± 0.22 and SG2 with higher diversity (Shannon-Weiner index: 5.95 ± 0.25. Hosts’ 28S rDNA sequences further confirmed that the sponge specimens were composed of two taxa closely related to Cinachyrella kuekenthalli. Both sponge groups were dominated by Proteobacteria, but Alphaproteobacteria were significantly more abundant in SG1. SG2 harbored many bacterial phyla (>1% of sequences present in low abundance or below detection limits (<0.07% in SG1 including: Acidobacteria, Chloroflexi, Gemmatimonadetes, Nitrospirae, PAUC34f, Poribacteria and Verrucomicrobia. Furthermore, SG1 and SG2 only had 95 OTUs in common, representing 30.5% and 22.4% of SG1 and SG2’s total OTUs, respectively. These results suggest that the sponge host may exert a pivotal influence on the nature and structure of the microbial community and may only be marginally affected by external environment parameters.

  11. Contraceptive Sponge

    Science.gov (United States)

    ... cause: Vaginal irritation or dryness Urinary tract or vaginal infection An increased risk of contracting STIs Toxic shock ... 24 hours to reduce the risk of an infection. Remove the contraceptive ... If your vaginal muscles are still holding the contraceptive sponge tightly, ...

  12. The corallivorous invertebrate Drupella aids in transmission of brown band disease on the Great Barrier Reef

    Science.gov (United States)

    Nicolet, K. J.; Hoogenboom, M. O.; Gardiner, N. M.; Pratchett, M. S.; Willis, B. L.

    2013-06-01

    Brown band disease (BrB) is an increasingly prevalent coral disease in the Indo-Pacific, but although the macroscopic signs of BrB have been associated with the ciliate Philaster guamensis, many aspects of its ecology remain unknown, particularly how the disease is transmitted among coral colonies. The aim of this study was to assess biotic factors affecting BrB transmission, explicitly testing whether corallivorous species contribute to disease spread. Several fish species were observed feeding on diseased tissue in the field, but did not influence either the progression or transmission rates of BrB on coral colonies in situ. In aquarium-based experiments, the butterflyfish Chaetodon aureofasciatus neither aided nor hindered the transmission of BrB from infected to uninfected corals. In contrast, the coral-feeding gastropod Drupella sp. was a highly effective vector of BrB, infecting more than 40 % of experimental colonies. This study also demonstrated the importance of injury in facilitating BrB infection, supporting the hypothesis that the BrB pathogen invades compromised coral tissue. In conclusion, disturbances and corallivorous activities that injure live corals are likely to contribute to increased occurrence of BrB provided that feeding scars create entry wounds sufficiently extensive to facilitate infection. These findings increase the understanding of the ecology of BrB, enabling better predictions of the prevalence and severity of this disease, and informing strategies for managing the impact of BrB on coral reefs.

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

    Directory of Open Access Journals (Sweden)

    Friedrich W Meyer

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

  14. Preliminary assessment of sponge biodiversity on Saba Bank, Netherlands Antilles.

    Directory of Open Access Journals (Sweden)

    Robert W Thacker

    Full Text Available BACKGROUND: Saba Bank Atoll, Netherlands Antilles, is one of the three largest atolls on Earth and provides habitat for an extensive coral reef community. To improve our knowledge of this vast marine resource, a survey of biodiversity at Saba Bank included a multi-disciplinary team that sampled fishes, mollusks, crustaceans, macroalgae, and sponges. METHODOLOGY/PRINCIPAL FINDINGS: A single member of the dive team conducted surveys of sponge biodiversity during eight dives at six locations, at depths ranging from 15 to 30 m. This preliminary assessment documented the presence of 45 species pooled across multiple locations. Rarefaction analysis estimated that only 48 to 84% of species diversity was sampled by this limited effort, clearly indicating a need for additional surveys. An analysis of historical collections from Saba and Saba Bank revealed an additional 36 species, yielding a total of 81 sponge species recorded from this area. CONCLUSIONS/SIGNIFICANCE: This observed species composition is similar to that found on widespread Caribbean reefs, indicating that the sponge fauna of Saba Bank is broadly representative of the Caribbean as a whole. A robust population of the giant barrel sponge, Xestospongia muta, appeared healthy with none of the signs of disease or bleaching reported from other Caribbean reefs; however, more recent reports of anchor chain damage to these sponges suggests that human activities can have dramatic impacts on these communities. Opportunities to protect this extremely large habitat should be pursued, as Saba Bank may serve as a significant reservoir of sponge species diversity.

  15. Vaginal sponge and spermicides

    Science.gov (United States)

    ... counter; Contraceptives - over the counter; Family planning - vaginal sponge; Contraception - vaginal sponge ... Spermicides and vaginal sponges do not work as well at preventing pregnancy as some other forms of birth control. However, using a spermicide ...

  16. Cyanotoxins are not implicated in the etiology of coral black band disease outbreaks on Pelorus Island, Great Barrier Reef.

    Science.gov (United States)

    Glas, Martin S; Motti, Cherie A; Negri, Andrew P; Sato, Yui; Froscio, Suzanne; Humpage, Andrew R; Krock, Bernd; Cembella, Allan; Bourne, David G

    2010-07-01

    Cyanobacterial toxins (i.e. microcystins) produced within the microbial mat of coral black band disease (BBD) have been implicated in disease pathogenicity. This study investigated the presence of toxins within BBD lesions and other cyanobacterial patch (CP) lesions, which, in some instances ( approximately 19%), facilitated the onset of BBD, from an outbreak site at Pelorus Island on the inshore, central Great Barrier Reef (GBR). Cyanobacterial species that dominated the biomass of CP and BBD lesions were cultivated and identified, based on morphology and 16S rRNA gene sequences, as Blennothrix- and Oscillatoria-affiliated species, respectively, and identical to cyanobacterial sequences retrieved from previous molecular studies from this site. The presence of the cyanotoxins microcystin, cylindrospermopsin, saxitoxin, nodularin and anatoxin and their respective gene operons in field samples of CP and BBD lesions and their respective culture isolations was tested using genetic (PCR-based screenings), chemical (HPLC-UV, FTICR-MS and LC/MS(n)) and biochemical (PP2A) methods. Cyanotoxins and cyanotoxin synthetase genes were not detected in any of the samples. Cyanobacterial species dominant within CP and BBD lesions were phylogenetically distinct from species previously shown to produce cyanotoxins and isolated from BBD lesions. The results from this study demonstrate that cyanobacterial toxins appear to play no role in the pathogenicity of CP and BBD at this site on the GBR.

  17. The Great Barrier Reef World Heritage Area seagrasses: Managing this iconic Australian ecosystem resource for the future

    Science.gov (United States)

    Coles, Robert G.; Rasheed, Michael A.; McKenzie, Len J.; Grech, Alana; York, Paul H.; Sheaves, Marcus; McKenna, Skye; Bryant, Catherine

    2015-02-01

    The Great Barrier Reef World Heritage Area (GBRWHA) includes one of the world's largest areas of seagrass (35,000 km2) encompassing approximately 20% of the world's species. Mapping and monitoring programs sponsored by the Australian and Queensland Governments and Queensland Port Authorities have tracked a worrying decrease in abundance and area since 2007. This decline has almost certainly been the result of a series of severe tropical storms and associated floods exacerbating existing human induced stressors. A complex variety of marine and terrestrial management actions and plans have been implemented to protect seagrass and other habitats in the GBRWHA. For seagrasses, these actions are inadequate. They provide an impression of effective protection of seagrasses; reduce the sense of urgency needed to trigger action; and waste the valuable and limited supply of "conservation capital". There is a management focus on ports, driven by public concerns about high profile development projects, which exaggerates the importance of these relatively concentrated impacts in comparison to the total range of threats and stressors. For effective management of seagrass at the scale of the GBRWHA, more emphasis needs to be placed on the connectivity between seagrass meadow health, watersheds, and all terrestrial urban and agricultural development associated with human populations. The cumulative impacts to seagrass from coastal and marine processes in the GBRWHA are not evenly distributed, with a mosaic of high and low vulnerability areas. This provides an opportunity to make choices for future coastal development plans that minimise stress on seagrass meadows.

  18. Linking the Local and the Global. What Today’s Environmental Humanities Movement Can Learn from Their Predecessor’s Successful Leadership of the 1965–1975 War to Save the Great Barrier Reef

    Directory of Open Access Journals (Sweden)

    Iain McCalman

    2017-10-01

    Full Text Available For a decade from 1965–1975, an Australian poet, Judith Wright, and a Reef artist, John Busst, played a major role in helping to save the Great Barrier Reef. The Queensland State Government had declared its intention of mining up to eighty percent of the Reef’s corals for oil, gas, fertiliser and cement. The campaign of resistance led by these two humanists, in alliance with a forester, Dr. Len Webb, contributed substantively to the establishment of the Great Barrier Reef Marine Park in 1975 and to then to the Reef’s World Heritage listing in 1983 as ‘the most impressive marine environment in the world’. This paper explains the challenges facing today’s environmental scholars and activists as they attempt to replicate the success of their 1970s predecessors in helping to save the Great Barrier Reef from even graver and more immediate threats to its survival.

  19. Climate change in the Cairns and Great Barrier Reef region. Scope and Focus for an Integrated Assessment

    International Nuclear Information System (INIS)

    Crimp, S.; Balston, J.; Ash, A.; Anderson-Berry, L.; Done, T.; Greiner, R.; Hilbert, D.; Howden, M.; Jones, R.; Stokes, C.; Stoeckl, N.; Sutherst, B.; Whetton, P.

    2004-07-01

    This study was undertaken to determine the scope and focus for an integrated assessment of climate change impacts on, and adaptation options for, the Cairns Great Barrier Reef (CGBR) region. To achieve this, the authors employed both technical expertise and regional stakeholder input. This document describes the study objectives and the process used to meet these objectives, and provides an overview of the CGBR region, the views of technical experts on potential climate change impacts, stakeholder prioritisation of impacts and adaptation options, a list of perceived knowledge gaps, and a recommended structure for a future integrated assessment in the region. The aim of the study was to determine the scope and focus for an integrated regional assessment of climate change impacts on, and adaptation options for, the CGBR region. The key objectives of the study were: Define and describe the study region; Develop a process for the study, which includes key stakeholders in the region; Prepare a comprehensive list of the regional stakeholders; Brief regional stakeholders about potential climate changes in the region; Gain insight from stakeholders into the climatic dependencies of key sectors and issues in the region (agriculture, fishing, forestry, tourism, natural ecosystems, infrastructure, pests, diseases and human health); Identify possible adaptation and/or amelioration strategies for each sector; Identify synergies with other sectors, and possible barriers to undertaking climate change adaptation strategies; Identify knowledge gaps, research priorities and current activities that may need alteration or enhancement; Define the scope of a possible integrated assessment of climate change impacts on, and adaptation options for, the region

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

    Science.gov (United States)

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

  1. Microsatellites Reveal Genetic Homogeneity among Outbreak Populations of Crown-of-Thorns Starfish (Acanthaster cf. solaris) on Australia’s Great Barrier Reef

    KAUST Repository

    Harrison, Hugo

    2017-03-10

    Specific patterns in the initiation and spread of reef-wide outbreaks of crown-of-thorns starfish are important, both to understand potential causes (or triggers) of outbreaks and to develop more effective and highly targeted management and containment responses. Using analyses of genetic diversity and structure (based on 17 microsatellite loci), this study attempted to resolve the specific origin for recent outbreaks of crown-of-thorns on Australia’s Great Barrier Reef (GBR). We assessed the genetic structure amongst 2705 starfish collected from 13 coral reefs in four regions that spanned ~1000 km of the GBR. Our results indicate that populations sampled across the full length of the GBR are genetically homogeneous (G’ST = −0.001; p = 0.948) with no apparent genetic structure between regions. Approximate Bayesian computational analyses suggest that all sampled populations had a common origin and that current outbreaking populations of crown-of-thorns starfish (CoTS) in the Swains are not independent of outbreak populations in the northern GBR. Despite hierarchical sampling and large numbers of CoTS genotyped from individual reefs and regions, limited genetic structure meant we were unable to determine a putative source population for the current outbreak of CoTS on the GBR. The very high genetic homogeneity of sampled populations and limited evidence of inbreeding indicate rapid expansion in population size from multiple, undifferentiated latent populations.

  2. Microsatellites Reveal Genetic Homogeneity among Outbreak Populations of Crown-of-Thorns Starfish (Acanthaster cf. solaris) on Australia’s Great Barrier Reef

    KAUST Repository

    Harrison, Hugo; Pratchett, Morgan; Messmer, Vanessa; Saenz-Agudelo, Pablo; Berumen, Michael L.

    2017-01-01

    Specific patterns in the initiation and spread of reef-wide outbreaks of crown-of-thorns starfish are important, both to understand potential causes (or triggers) of outbreaks and to develop more effective and highly targeted management and containment responses. Using analyses of genetic diversity and structure (based on 17 microsatellite loci), this study attempted to resolve the specific origin for recent outbreaks of crown-of-thorns on Australia’s Great Barrier Reef (GBR). We assessed the genetic structure amongst 2705 starfish collected from 13 coral reefs in four regions that spanned ~1000 km of the GBR. Our results indicate that populations sampled across the full length of the GBR are genetically homogeneous (G’ST = −0.001; p = 0.948) with no apparent genetic structure between regions. Approximate Bayesian computational analyses suggest that all sampled populations had a common origin and that current outbreaking populations of crown-of-thorns starfish (CoTS) in the Swains are not independent of outbreak populations in the northern GBR. Despite hierarchical sampling and large numbers of CoTS genotyped from individual reefs and regions, limited genetic structure meant we were unable to determine a putative source population for the current outbreak of CoTS on the GBR. The very high genetic homogeneity of sampled populations and limited evidence of inbreeding indicate rapid expansion in population size from multiple, undifferentiated latent populations.

  3. Microbial and chemical transformation studies of the bioactive marine sesquiterpenes (S)-(+)-curcuphenol and -curcudiol isolated from a deep reef collection of the Jamaican sponge Didiscus oxeata.

    Science.gov (United States)

    El Sayed, Khalid A; Yousaf, Muhammad; Hamann, Mark T; Avery, Mitchell A; Kelly, Michelle; Wipf, Peter

    2002-11-01

    Microbial and chemical transformation studies of the marine sesquiterpene phenols (S)-(+)-curcuphenol (1) and (S)-(+)-curcudiol (2), isolated from the Jamaican sponge Didiscus oxeata, were accomplished. Preparative-scale fermentation of 1 with Kluyveromyces marxianus var. lactis (ATCC 2628) has resulted in the isolation of six new metabolites: (S)-(+)-15-hydroxycurcuphenol (3), (S)-(+)-12-hydroxycurcuphenol (4), (S)-(+)-12,15-dihydroxycurcuphenol (5), (S)-(+)-15-hydroxycurcuphenol-12-al (6), (S)-(+)-12-carboxy-10,11-dihydrocurcuphenol (7), and (S)-(+)-12-hydroxy-10,11-dihydrocurcuphenol (8). Fourteen-days incubation of 1 with Aspergillus alliaceus (NRRL 315) afforded the new compounds (S)-(+)-10beta-hydroxycurcudiol (9), (S)-(+)-curcudiol-10-one (10), and (S)-(+)-4-[1-(2-hydroxy-4-methyl)phenyl)]pentanoic acid (11). Rhizopus arrhizus (ATCC 11145) and Rhodotorula glutinus (ATCC 15125) afforded (S)-curcuphenol-1alpha-D-glucopyranoside (12) and (S)-curcudiol-1alpha-D-glucopyranoside (13) when incubated for 6 and 8 days with 1 and 2, respectively. The absolute configuration of C(10) and C(11) of metabolites 7-9 was established by optical rotation computations. Reaction of 1 with NaNO(2) and HCl afforded (S)-(+)-4-nitrocurcuphenol (14) and (S)-(+)-2-nitrocurcuphenol (15) in a 2:1 ratio. Acylation of 1 and 2 with isonicotinoyl chloride afforded the expected esters (S)-(+)-curcuphenol-1-O-isonicotinate (16) and (S)-(+)-curcudiol-1-O-isonicotinate (17), respectively. Curcuphenol (1) shows potent antimicrobial activity against Candida albicans, Cryptococcus neoformans, methicillin-resistant Staphylococcus aureus, and S. aureus with MIC and MFC/MBC ranges of 7.5-25 and 12.5-50 microg/mL, respectively. Compounds 1 and 3 also display in vitro antimalarial activity against Palsmodium falciparium (D6 clone) with MIC values of 3600 and 3800 ng/mL, respectively (selectivity index >1.3). Both compounds were also active against P. falciparium (W2 clone) with MIC values of 1800 (S

  4. UPPER TRIASSIC (NORIAN-RHAETIAN HYPERCALCIFIED SPONGES FROM THE LUT BLOCK, EAST CENTRAL IRAN

    Directory of Open Access Journals (Sweden)

    FATEMEH AMIRHASSANKHANI

    2014-11-01

    Full Text Available In order to study the hypercalcified sponges in reefal deposits of the Nayband Formation in Lut Block, the Garm Ab section near the village of Mehran Kushk, located about 20 km northeast of Ferdows city, was sampled. Eight horizons of reefal limestone beds are exposed in this section. The most important reef builders are hypercalcified sponges with some representatives of hexactinellids, scleractinian corals and other reef organisms. The field and lab-observations on rock units, sedimentary facies and faunal assemblages indicate the middle Norian-Rhaetian as the age of the reef horizons. Twenty-three sponge taxa, including 15 of the chambered sphinctozoans, 2 of hexactinellids sponges and 8 non-chambered inozoan were identified. The majority of recognized sponges are reported from the Nayband Formation from the other localities in central Iran. One new species identified as Cryptocoelia maxima n. sp. was recovered and is described here.

  5. Seven new species of Paleanotus (Annelida: Chrysopetalidae) described from Lizard Island, Great Barrier Reef, and coral reefs of northern Australia and the Indo-Pacific: two cryptic species pairs revealed between western Pacific Ocean and the eastern Indian Ocean.

    Science.gov (United States)

    Watson, Charlotte

    2015-09-18

    Morphological investigation into the paleate genus Paleanotus Schmarda 1861 of the family Chrysopetalidae from northern Australian coral reefs, primarily Lizard Island and outlying reefs, included a complex of very small, slender individuals (length < 5 mm). This complex resolved into 7 new species, described herein: Paleanotus inornatus n. sp., P. adornatus n. sp., P. chrysos n. sp., P. aquifolia n. sp., P. latifolia n. sp., P. silus n. sp., and P. silopsis n. sp. A key is provided to the new species and Paleanotus distinguished from Treptopale and Hyalopale, two closely related genera. Diagnostic features of the apical structure and shape of the notochaetal main paleae plus median paleae shape and raised rib pattern, differentiates each species from the other. Gametous states are described. Two cryptic species pairs (Paleanotus silopsis n. sp. and P. silus n. sp.; Paleanotus aquifolia n. sp. and P. latifolia n. sp.) were identified. In each case one species is restricted to either the NE or NW Australian coast. In each pair the most eastern point for the NW Australian species range occurs at Darwin, western Arnhemland, Northern Territory. Additional material for each species pair extends their respective ranges northwards: NW Australia to Thailand, Andaman Sea, eastern Indian Ocean or NE Australia, Great Barrier Reef to the Philippines, western Pacific Ocean. Cryptic morphology and potential genetic diversity is discussed in Paleanotus inornatus n. sp. and P. adornatus n. sp. that possess overlapping widespread distribution patterns across northern Australia and Indo-Pacific reefs. The smallest bodied taxon, Paleanotus chrysos n. sp. is the only species with a Coral Sea range encompassing Lizard Island, Heron Island and New Caledonia.

  6. U-Th dating reveals regional-scale decline of branching Acropora corals on the Great Barrier Reef over the past century

    Science.gov (United States)

    Clark, Tara R.; Roff, George; Zhao, Jian-xin; Feng, Yue-xing; Done, Terence J.; McCook, Laurence J.; Pandolfi, John M.

    2017-09-01

    Hard coral cover on the Great Barrier Reef (GBR) is on a trajectory of decline. However, little is known about past coral mortality before the advent of long-term monitoring (circa 1980s). Using paleoecological analysis and high-precision uranium-thorium (U-Th) dating, we reveal an extensive loss of branching Acropora corals and changes in coral community structure in the Palm Islands region of the central GBR over the past century. In 2008, dead coral assemblages were dominated by large, branching Acropora and living coral assemblages by genera typically found in turbid inshore environments. The timing of Acropora mortality was found to be occasionally synchronous among reefs and frequently linked to discrete disturbance events, occurring in the 1920s to 1960s and again in the 1980s to 1990s. Surveys conducted in 2014 revealed low Acropora cover (shifted baseline.

  7. Prevalence of virus-like particles within a staghorn scleractinian coral ( Acropora muricata) from the Great Barrier Reef

    Science.gov (United States)

    Patten, N. L.; Harrison, P. L.; Mitchell, J. G.

    2008-09-01

    Transmission electron microscopy (TEM) was used to determine whether Acropora muricata coral colonies from the Great Barrier Reef (GBR), Australia, harboured virus-like particles (VLPs). VLPs were present in all coral colonies sampled at Heron Island (southern GBR) and in tagged coral colonies sampled in at least two of the three sampling periods at Lizard Island (northern GBR). VLPs were observed within gastrodermal and epidermal tissues, and on rarer occasions, within the mesoglea. These VLPs had similar morphologies to known prokaryotic and eukaryotic viruses in other systems. Icosahedral VLPs were observed most frequently, however, filamentous VLPs (FVLPs) and phage were also noted. There were no clear differences in VLP size, morphology or location within the tissues with respect to sample date, coral health status or site. The most common VLP morphotype exhibited icosahedral symmetry, 120-150 nm in diameter, with an electron-dense core and an electronlucent membrane. Larger VLPs of similar morphology were also common. VLPs occurred as single entities, in groups, or in dense clusters, either as free particles within coral tissues, or within membrane-bound vacuoles. VLPs were commonly observed within the perinuclear region, with mitochondria, golgi apparatus and crescent-shaped particles frequently observed within close proximity. The host(s) of these observed VLPs was not clear; however, the different sizes and morphologies of VLPs observed within A. muricata tissues suggest that viruses are infecting either the coral animal, zooxanthellae, intracellular bacteria and/or other coral-associated microbiota, or that the one host is susceptible to infection from more than one type of virus. These results add to the limited but emerging body of evidence that viruses represent another potentially important component of the coral holobiont.

  8. Fecal bacterial communities of wild-captured and stranded green turtles (Chelonia mydas) on the Great Barrier Reef.

    Science.gov (United States)

    Ahasan, Md Shamim; Waltzek, Thomas B; Huerlimann, Roger; Ariel, Ellen

    2017-12-01

    Green turtles (Chelonia mydas) are endangered marine herbivores that break down food particles, primarily sea grasses, through microbial fermentation. However, the microbial community and its role in health and disease is still largely unexplored. In this study, we investigated and compared the fecal bacterial communities of eight wild-captured green turtles to four stranded turtles in the central Great Barrier Reef regions that include Bowen and Townsville. We used high-throughput sequencing analysis targeting the hypervariable V1-V3 regions of the bacterial 16S rRNA gene. At the phylum level, Firmicutes predominated among wild-captured green turtles, followed by Bacteroidetes and Proteobacteria. In contrast, Proteobacteria (Gammaproteobacteria) was the most significantly dominant phylum among all stranded turtles, followed by Bacteroidetes and Firmicutes. In addition, Fusobacteria was also significantly abundant in stranded turtles. No significant differences were found between the wild-captured turtles in Bowen and Townsville. At the family level, the core bacterial community consisted of 25 families that were identified in both the wild-captured and stranded green turtles, while two unique sets of 14 families each were only found in stranded or wild-captured turtles. The predominance of Bacteroides in all groups indicates the importance of these bacteria in turtle gut health. In terms of bacterial diversity and richness, wild-captured green turtles showed a higher bacterial diversity and richness compared with stranded turtles. The marked differences in the bacterial communities between wild-captured and stranded turtles suggest the possible dysbiosis in stranded turtles in addition to potential causal agents. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Epilithic Cyanobacterial Communities of a Marine Tropical Beach Rock (Heron Island, Great Barrier Reef): Diversity and Diazotrophy▿

    Science.gov (United States)

    Díez, Beatriz; Bauer, Karolina; Bergman, Birgitta

    2007-01-01

    The diversity and nitrogenase activity of epilithic marine microbes in a Holocene beach rock (Heron Island, Great Barrier Reef, Australia) with a proposed biological calcification “microbialite” origin were examined. Partial 16S rRNA gene sequences from the dominant mat (a coherent and layered pink-pigmented community spread over the beach rock) and biofilms (nonstratified, differently pigmented microbial communities of small shallow depressions) were retrieved using denaturing gradient gel electrophoresis (DGGE), and a clone library was retrieved from the dominant mat. The 16S rRNA gene sequences and morphological analyses revealed heterogeneity in the cyanobacterial distribution patterns. The nonheterocystous filamentous genus Blennothrix sp., phylogenetically related to Lyngbya, dominated the mat together with unidentified nonheterocystous filaments of members of the Pseudanabaenaceae and the unicellular genus Chroococcidiopsis. The dominance and three-dimensional intertwined distribution of these organisms were confirmed by nonintrusive scanning microscopy. In contrast, the less pronounced biofilms were dominated by the heterocystous cyanobacterial genus Calothrix, two unicellular Entophysalis morphotypes, Lyngbya spp., and members of the Pseudanabaenaceae family. Cytophaga-Flavobacterium-Bacteroides and Alphaproteobacteria phylotypes were also retrieved from the beach rock. The microbial diversity of the dominant mat was accompanied by high nocturnal nitrogenase activities (as determined by in situ acetylene reduction assays). A new DGGE nifH gene optimization approach for cyanobacterial nitrogen fixers showed that the sequences retrieved from the dominant mat were related to nonheterocystous uncultured cyanobacterial phylotypes, only distantly related to sequences of nitrogen-fixing cultured cyanobacteria. These data stress the occurrence and importance of nonheterocystous epilithic cyanobacteria, and it is hypothesized that such epilithic cyanobacteria

  10. Root-derived organic matter confines sponge community composition in mangrove ecosystems

    NARCIS (Netherlands)

    Hunting, E.R.; Ubels, S.M.; Kraak, M.H.S.; van der Geest, H.G.

    2013-01-01

    Introduction Caribbean mangrove-associated sponge communities are very distinct from sponge communities living on nearby reefs, but the mechanisms that underlie this distinction remain uncertain. It has been hypothesized that dissolved organic matter (DOM) leaching from mangrove roots and the

  11. Diversity and spatial heterogeneity of mangrove associated sponges of Curaçao and Aruba

    NARCIS (Netherlands)

    Hunting, E.R.; van Soest, R.W.M.; van der Geest, H.G.; Vos, A.; Debrot, A.O.

    2008-01-01

    Sponges are major epibionts of mangrove roots in the Caribbean. Mangrove sponge communities in the Caribbean mainly consist of species that are typical to this habitat and community compositions often differ from those found on coral reefs nearby. Heterogeneity in species distributions between

  12. Cell kinetics of the marine sponge Halisarca caerulea reveal rapid cell turnover and shedding

    NARCIS (Netherlands)

    Goeij, de J.M.; Kluijver, de A.; Duyl, van F.C.; Vacelet, J.; Wijffels, R.H.; Goeij, de A.F.P.M.; Cleutjens, J.P.M.; Schutte, B.

    2009-01-01

    This study reveals the peculiar in vivo cell kinetics and cell turnover of the marine sponge Halisarca caerulea under steady-state conditions. The tropical coral reef sponge shows an extremely high proliferation activity, a short cell cycle duration and massive cell shedding. Cell turnover is

  13. Diversity and spatial heterogeneity of mangrove associated sponges of Curaçao and Aruba

    OpenAIRE

    Hunting, E.R.; van Soest, R.W.M.; van der Geest, H.G.; Vos, A.; Debrot, A.O.

    2008-01-01

    Sponges are major epibionts of mangrove roots in the Caribbean. Mangrove sponge communities in the Caribbean mainly consist of species that are typical to this habitat and community compositions often differ from those found on coral reefs nearby. Heterogeneity in species distributions between locations and within locations between roots is often reported. This study quantifi es the diversity and abundance of mangrove associated sponges in the inner bays of Curaçao and Aruba and correlates va...

  14. Spatial variability of initial 230Th/ 232Th in modern Porites from the inshore region of the Great Barrier Reef

    Science.gov (United States)

    Clark, Tara R.; Zhao, Jian-xin; Feng, Yue-xing; Done, Terry J.; Jupiter, Stacy; Lough, Janice; Pandolfi, John M.

    2012-02-01

    The main limiting factor in obtaining precise and accurate uranium-series (U-series) ages of corals that lived during the last few hundred years is the ability to constrain and correct for initial thorium-230 ( 230Th 0), which is proportionally much higher in younger samples. This is becoming particularly important in palaeoecological research where accurate chronologies, based on the 230Th chronometer, are required to pinpoint changes in coral community structure and the timing of mortality events in recent time (e.g. since European settlement of northern Australia in the 1850s). In this study, thermal ionisation mass spectrometry (TIMS) U-series dating of 43 samples of known ages collected from living Porites spp. from the far northern, central and southern inshore regions of the Great Barrier Reef (GBR) was performed to spatially constrain initial 230Th/ 232Th ( 230Th/ 232Th 0) variability. In these living Porites corals, the majority of 230Th/ 232Th 0 values fell within error of the conservative bulk Earth 230Th/ 232Th atomic value of 4.3 ± 4.3 × 10 -6 (2 σ) generally assumed for 230Th 0 corrections where the primary source is terrestrially derived. However, the results of this study demonstrate that the accuracy of 230Th ages can be further improved by using locally determined 230Th/ 232Th 0 values for correction, supporting the conclusion made by Shen et al. (2008) for the Western Pacific. Despite samples being taken from regions adjacent to contrasting levels of land modification, no significant differences were found in 230Th/ 232Th 0 between regions exposed to varying levels of sediment during river runoff events. Overall, 39 of the total 43 230Th/ 232Th 0 atomic values measured in samples from inshore reefs across the entire region show a normal distribution ranging from 3.5 ± 1.1 to 8.1 ± 1.1 × 10 -6, with a weighted mean of 5.76 ± 0.34 × 10 -6 (2 σ, MSWD = 8.1). Considering the scatter of the data, the weighted mean value with a more

  15. Water Quality and River Plume Monitoring in the Great Barrier Reef: An Overview of Methods Based on Ocean Colour Satellite Data

    Directory of Open Access Journals (Sweden)

    Michelle J. Devlin

    2015-09-01

    Full Text Available A strong driver of water quality change in the Great Barrier Reef (GBR is the pulsed or intermittent nature of terrestrial inputs into the GBR lagoon, including delivery of increased loads of sediments, nutrients, and toxicants via flood river plumes (hereafter river plumes during the wet season. Cumulative pressures from extreme weather with a high frequency of large scale flooding in recent years has been linked to the large scale reported decline in the health of inshore seagrass systems and coral reefs in the central areas of the GBR, with concerns for the recovery potential of these impacted ecosystems. Management authorities currently rely on remotely-sensed (RS and in situ data for water quality monitoring to guide their assessment of water quality conditions in the GBR. The use of remotely-sensed satellite products provides a quantitative and accessible tool for scientists and managers. These products, coupled with in situ data, and more recently modelled data, are valuable for quantifying the influence of river plumes on seagrass and coral reef habitat in the GBR. This article reviews recent remote sensing techniques developed to monitor river plumes and water quality in the GBR. We also discuss emerging research that integrates hydrodynamic models with remote sensing and in situ data, enabling us to explore impacts of different catchment management strategies on GBR water quality.

  16. Assessment of Invasiveness of the Orange Keyhole Sponge Mycale Armata in Kaneohe Bay, Oahu, Hawaii Based on Surveys 2005-2006, Year 2 of Hawaii Coral Reef Initiative (NODC Accession 0033380)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Orange Keyhole Sponge, Mycale armata Thiele, was unknown in Hawaii prior to 1996. It was first reported in Pearl Harbor and has been reported in low abundance...

  17. Exposure of inshore corals to suspended sediments due to wave-resuspension and river plumes in the central Great Barrier Reef: A reappraisal

    Science.gov (United States)

    Orpin, Alan R.; Ridd, Peter V.

    2012-09-01

    Suspended sediment in the coastal zone is an important limiting factor for the growth and health of inshore coral reefs. The Great Barrier Reef (GBR) lagoon receives sediment from a number of tropical rivers and the physical and biological effects of riverine discharge and turbidity within the lagoon are of considerable scientific and public interest. Published data from two inshore regions of the GBR are reviewed herein to evaluate the relative influence of river plumes and wave resuspension on suspended sediment concentration (SSC) around coral communities over a range of timescales. Data from Cleveland Bay and from other sites near the mouth of the Tully River show that wave resuspension is the most dominant mechanism controlling SSC at inshore reefs. At many nearshore areas today fine-grained bed sediment is abundant, consistent with millennial-scale geological evidence of sediment dispersal prior to European settlement and catchment impacts. Flocculation, particle settling and dilution occurs within the river plume, and riverine sediment concentrations at reefs directly attributable to individual flood inputs is significantly reduced, suggesting that the plume component is a relatively small contribution to the total suspended sediment mass balance over inter-annual timescales. Resuspension events can generate higher ambient SSC than that measured in flood waters (e.g. Tully River). In addition, while visually spectacular, satellite and aerial images offer limited quantitative information of total sediment load carried by hypopycnal plumes, as many of these plumes may contain algal blooms but relatively low concentrations of suspended sediment (ca. processes common to many continental shelves globally. Despite the examples examined in detail herein, the role of frequency, magnitude and duration in determining the impact or exposure of corals to elevated SSCs is poorly constrained by limited quantitative measurements during events, and our ability to place

  18. 1300 km long late Pleistocene-Holocene shelf edge barrier reef system along the western continental shelf of India: Occurrence and significance

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Wagle, B.G.; Veerayya, M.; Almeida, F.; Karisiddaiah, S.M.

    . It is surmised that coral/algal reef growth commenced with the advent of the Holocene trangression and favorable antecedent topography, and continued until early Holocene. Subsequently, rapid sea level rise drowned the reefs. The shelf edge reefs, therefore...

  19. Satellite-Derived Photic Depth on the Great Barrier Reef: Spatio-Temporal Patterns of Water Clarity

    Directory of Open Access Journals (Sweden)

    Scarla Weeks

    2012-11-01

    Full Text Available Detecting changes to the transparency of the water column is critical for understanding the responses of marine organisms, such as corals, to light availability. Long-term patterns in water transparency determine geographical and depth distributions, while acute reductions cause short-term stress, potentially mortality and may increase the organisms’ vulnerability to other environmental stressors. Here, we investigated the optimal, operational algorithm for light attenuation through the water column across the scale of the Great Barrier Reef (GBR, Australia. We implemented and tested a quasi-analytical algorithm to determine the photic depth in GBR waters and matched regional Secchi depth (ZSD data to MODIS-Aqua (2002–2010 and SeaWiFS (1997–2010 satellite data. The results of the in situ ZSD/satellite data matchup showed a simple bias offset between the in situ and satellite retrievals. Using a Type II linear regression of log-transformed satellite and in situ data, we estimated ZSD and implemented the validated ZSD algorithm to generate a decadal satellite time series (2002–2012 for the GBR. Water clarity varied significantly in space and time. Seasonal effects were distinct, with lower values during the austral summer, most likely due to river runoff and increased vertical mixing, and a decline in water clarity between 2008–2012, reflecting a prevailing La Niña weather pattern. The decline in water clarity was most pronounced in the inshore area, where a significant decrease in mean inner shelf ZSD of 2.1 m (from 8.3 m to 6.2 m occurred over the decade. Empirical Orthogonal Function Analysis determined the dominance of Mode 1 (51.3%, with the greatest variation in water clarity along the mid-shelf, reflecting the strong influence of oceanic intrusions on the spatio-temporal patterns of water clarity. The newly developed photic depth product has many potential applications for the GBR from water quality monitoring to analyses of

  20. Using MODIS data for understanding changes in seagrass meadow health: a case study in the Great Barrier Reef (Australia).

    Science.gov (United States)

    Petus, Caroline; Collier, Catherine; Devlin, Michelle; Rasheed, Michael; McKenna, Skye

    2014-07-01

    Stretching more than 2000 km along the Queensland coast, the Great Barrier Reef Marine Park (GBR) shelters over 43,000 square km of seagrass meadows. Despite the status of marine protected area and World Heritage listing of the GBR, local seagrass meadows are under stress from reduced water quality levels; with reduction in the amount of light available for seagrass photosynthesis defined as the primary cause of seagrass loss throughout the GBR. Methods have been developed to map GBR plume water types by using MODIS quasi-true colour (hereafter true colour) images reclassified in function of their dominant colour. These data can be used as an interpretative tool for understanding changes in seagrass meadow health (as defined in this study by the seagrass area and abundance) at different spatial and temporal scales. We tested this method in Cleveland Bay, in the northern GBR, where substantial loss in seagrass area and biomass was detected by annual monitoring from 2007 to 2011. A strong correlation was found between bay-wide seagrass meadow area and biomass and exposure to turbid Primary (sediment-dominated) water type. There was also a strong correlation between the changes of biomass and area of individual meadows and exposure of seagrass ecosystems to Primary water type over the 5-year period. Seagrass meadows were also grouped according to the dominant species within each meadow, irrespective of location within Cleveland Bay. These consolidated community types did not correlate well with the exposure to Primary water type, and this is likely to be due to local environmental conditions with the individual meadows that comprise these groupings. This study proved that remote sensing data provide the synoptic window and repetitivity required to investigate changes in water quality conditions over time. Remote sensing data provide an opportunity to investigate the risk of marine-coastal ecosystems to light limitation due to increased water turbidity when in situ

  1. Water use benefit index as a tool for community-based monitoring of water related trends in the Great Barrier Reef region

    Science.gov (United States)

    Smajgl, A.; Larson, S.; Hug, B.; De Freitas, D. M.

    2010-12-01

    SummaryThis paper presents a tool for documenting and monitoring water use benefits in the Great Barrier Reef catchments that allows temporal and spatial comparison along the region. Water, water use benefits and water allocations are currently receiving much attention from Australian policy makers and conservation practitioners. Because of the inherent complexity and variability in water quality, it is essential that scientific information is presented in a meaningful way to policy makers, managers and ultimately, to the general public who have to live with the consequences of the decisions. We developed an inexpensively populated and easily understandable water use benefit index as a tool for community-based monitoring of water related trends in the Great Barrier Reef region. The index is developed based on a comparative list of selected water-related indices integrating attributes across physico-chemical, economic, social, and ecological domains currently used in the assessment of water quality, water quantity and water use benefits in Australia. Our findings indicate that the proposed index allows the identification of water performance indicators by temporal and spatial comparisons. Benefits for decision makers and conservation practitioners include a flexible way of prioritization towards the domain with highest concern. The broader community benefits from a comprehensive and user-friendly tool, communicating changes in water quality trends more effectively.

  2. Differential recycling of coral and algal dissolved organic matter via the sponge loop

    NARCIS (Netherlands)

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

    Corals and macroalgae release large quantities of dissolved organic matter (DOM), one of the largest sources of organic matter produced on coral reefs. By rapidly taking up DOM and transforming it into particulate detritus, coral reef sponges are proposed to play a key role in transferring the

  3. SOME INOZOID SPONGES FROM UPPER TRIASSIC (NORIAN-RHAETIAN NAYBAND FORMATION OF CENTRAL IRAN

    Directory of Open Access Journals (Sweden)

    BABA SENOWBARI-DARYAN

    1997-11-01

    Full Text Available Some small-scaled Norian-Rhaetian reefs and reef mounds are imbedded within the shales, siltstones and siliciclastic-carbonate deposits of the Nayband Formation in central Iran. These deposits belong to the central Iranian plate as part of the Cimmerian Continent. Most of the biogenic rocks have a biostromal geometry, biohermal constructions are rare. Inozoid, sphinctozoid, and chaetetid sponges are, beside of corals and other reef builders, the most important reef organisms within these bioconstructions. In some reefs a variety of hexactinellid sponges also occur. The following inozoid sponges are described in this paper: Radiofibra norica n. sp., Permocorynella maxima n. sp., ?Sestrostomella robusta, Marawandia iranica, n. gen., n. sp. and Enaulofungia? triassica n. sp. The first four taxa are among the most abundant sponges within the Nayband Formation where it is exposed in several localities in central Iran. Enaulofungia? triassica, however, is not an abundant sponge there. These inozoid sponges have never been reported from the Triassic deposits of this region. Radiofibra, until now known only from the Upper Permian of Djebel Tebaga (Tunisia, is reported here for the first time from Triassic rocks. The stratigraphic as well as the paleogeographic distribution of all the genera are discussed.   

  4. The Life of a Sponge in a Sandy Lagoon.

    Science.gov (United States)

    Ilan, M; Abelson, A

    1995-12-01

    Infaunal soft-bottom invertebrates benefit from the presence of sediment, but sedimentation is potentially harmful for hard-bottom dwellers. Most sponges live on hard bottom, but on coral reefs in the Red Sea, the species Biemna ehrenbergi (Keller, 1889) is found exclusively in soft-bottom lagoons, usually in the shallowest part. This location is a sink environment, which increases the deposition of particulate organic matter. Most of the sponge body is covered by sediment, but the chimney-like siphons protrude from the sediment surface. The sponge is attached to the buried beach-rock, which reduces the risk of dislodgment during storms. Dye injected above and into the sediment revealed, for the first time, a sponge pumping interstitial water (rich with particles and nutrients) into its aquiferous system. Visual examination of plastic replicas of the aquiferous system and electron microscopical analysis of sponge tissue revealed that the transcellular ostia are mostly located on the buried surface of the sponge. The oscula, however, are located on top of the siphons; their elevated position and their ability to close combine to prevent the filtering system outflow from clogging. The transcellular ostia presumably remain open due to cellular mobility. The sponge maintains a large population of bacteriocytes, which contains bacteria of several different species. Some of these bacteria disintegrate, and may be consumed by the sponge.

  5. Gene Expression Dynamics Accompanying the Sponge Thermal Stress Response.

    Science.gov (United States)

    Guzman, Christine; Conaco, Cecilia

    2016-01-01

    Marine sponges are important members of coral reef ecosystems. Thus, their responses to changes in ocean chemistry and environmental conditions, particularly to higher seawater temperatures, will have potential impacts on the future of these reefs. To better understand the sponge thermal stress response, we investigated gene expression dynamics in the shallow water sponge, Haliclona tubifera (order Haplosclerida, class Demospongiae), subjected to elevated temperature. Using high-throughput transcriptome sequencing, we show that these conditions result in the activation of various processes that interact to maintain cellular homeostasis. Short-term thermal stress resulted in the induction of heat shock proteins, antioxidants, and genes involved in signal transduction and innate immunity pathways. Prolonged exposure to thermal stress affected the expression of genes involved in cellular damage repair, apoptosis, signaling and transcription. Interestingly, exposure to sublethal temperatures may improve the ability of the sponge to mitigate cellular damage under more extreme stress conditions. These insights into the potential mechanisms of adaptation and resilience of sponges contribute to a better understanding of sponge conservation status and the prediction of ecosystem trajectories under future climate conditions.

  6. The Sponge Pump: The Role of Current Induced Flow in the Design of the Sponge Body Plan

    Science.gov (United States)

    Leys, Sally P.; Yahel, Gitai; Reidenbach, Matthew A.; Tunnicliffe, Verena; Shavit, Uri; Reiswig, Henry M.

    2011-01-01

    Sponges are suspension feeders that use flagellated collar-cells (choanocytes) to actively filter a volume of water equivalent to many times their body volume each hour. Flow through sponges is thought to be enhanced by ambient current, which induces a pressure gradient across the sponge wall, but the underlying mechanism is still unknown. Studies of sponge filtration have estimated the energetic cost of pumping to be sponge Aphrocallistes vastus at a 150 m deep reef in situ and in a flow flume; we also modeled the glass sponge filtration system from measurements of the aquiferous system. Excurrent flow from the sponge osculum measured in situ and in the flume were positively correlated (r>0.75) with the ambient current velocity. During short bursts of high ambient current the sponges filtered two-thirds of the total volume of water they processed daily. Our model indicates that the head loss across the sponge collar filter is 10 times higher than previously estimated. The difference is due to the resistance created by a fine protein mesh that lines the collar, which demosponges also have, but was so far overlooked. Applying our model to the in situ measurements indicates that even modest pumping rates require an energetic expenditure of at least 28% of the total in situ respiration. We suggest that due to the high cost of pumping, current-induced flow is highly beneficial but may occur only in thin walled sponges living in high flow environments. Our results call for a new look at the mechanisms underlying current-induced flow and for reevaluation of the cost of biological pumping and its evolutionary role, especially in sponges. PMID:22180779

  7. The physiological response of two green calcifying algae from the Great Barrier Reef towards high dissolved inorganic and organic carbon (DIC and DOC availability.

    Directory of Open Access Journals (Sweden)

    Friedrich Wilhelm Meyer

    Full Text Available Increasing dissolved inorganic carbon (DIC concentrations associated with ocean acidification can affect marine calcifiers, but local factors, such as high dissolved organic carbon (DOC concentrations through sewage and algal blooms, may interact with this global factor. For calcifying green algae of the genus Halimeda, a key tropical carbonate producer that often occurs in coral reefs, no studies on these interactions have been reported. These data are however urgently needed to understand future carbonate production. Thus, we investigated the independent and combined effects of DIC (pCO2 402 μatm/ pHtot 8.0 and 996 μatm/ pHtot 7.7 and DOC (added as glucose in 0 and 294 μmol L-1 on growth, calcification and photosynthesis of H. macroloba and H. opuntia from the Great Barrier Reef in an incubation experiment over 16 days. High DIC concentrations significantly reduced dark calcification of H. opuntia by 130 % and led to net dissolution, but did not affect H. macroloba. High DOC concentrations significantly reduced daily oxygen production of H. opuntia and H. macroloba by 78 % and 43 %, respectively, and significantly reduced dark calcification of H. opuntia by 70%. Combined high DIC and DOC did not show any interactive effects for both algae, but revealed additive effects for H. opuntia where the combination of both factors reduced dark calcification by 162 % compared to controls. Such species-specific differences in treatment responses indicate H. opuntia is more susceptible to a combination of high DIC and DOC than H. macroloba. From an ecological perspective, results further suggest a reduction of primary production for Halimeda-dominated benthic reef communities under high DOC concentrations and additional decreases of carbonate accretion under elevated DIC concentrations, where H. opuntia dominates the benthic community. This may reduce biogenic carbonate sedimentation rates and hence the buffering capacity against further ocean

  8. The physiological response of two green calcifying algae from the Great Barrier Reef towards high dissolved inorganic and organic carbon (DIC and DOC) availability.

    Science.gov (United States)

    Meyer, Friedrich Wilhelm; Vogel, Nikolas; Teichberg, Mirta; Uthicke, Sven; Wild, Christian

    2015-01-01

    Increasing dissolved inorganic carbon (DIC) concentrations associated with ocean acidification can affect marine calcifiers, but local factors, such as high dissolved organic carbon (DOC) concentrations through sewage and algal blooms, may interact with this global factor. For calcifying green algae of the genus Halimeda, a key tropical carbonate producer that often occurs in coral reefs, no studies on these interactions have been reported. These data are however urgently needed to understand future carbonate production. Thus, we investigated the independent and combined effects of DIC (pCO2 402 μatm/ pHtot 8.0 and 996 μatm/ pHtot 7.7) and DOC (added as glucose in 0 and 294 μmol L-1) on growth, calcification and photosynthesis of H. macroloba and H. opuntia from the Great Barrier Reef in an incubation experiment over 16 days. High DIC concentrations significantly reduced dark calcification of H. opuntia by 130 % and led to net dissolution, but did not affect H. macroloba. High DOC concentrations significantly reduced daily oxygen production of H. opuntia and H. macroloba by 78 % and 43 %, respectively, and significantly reduced dark calcification of H. opuntia by 70%. Combined high DIC and DOC did not show any interactive effects for both algae, but revealed additive effects for H. opuntia where the combination of both factors reduced dark calcification by 162 % compared to controls. Such species-specific differences in treatment responses indicate H. opuntia is more susceptible to a combination of high DIC and DOC than H. macroloba. From an ecological perspective, results further suggest a reduction of primary production for Halimeda-dominated benthic reef communities under high DOC concentrations and additional decreases of carbonate accretion under elevated DIC concentrations, where H. opuntia dominates the benthic community. This may reduce biogenic carbonate sedimentation rates and hence the buffering capacity against further ocean acidification.

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

    Directory of Open Access Journals (Sweden)

    Caroline Petus

    2016-03-01

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

  10. Ecology of the ciguatera causing dinoflagellates from the Northern Great Barrier Reef: changes in community distribution and coastal eutrophication.

    Science.gov (United States)

    Skinner, Mark P; Lewis, Richard J; Morton, Steve

    2013-12-15

    Ciguatera fish poisoning (CFP) is known to be caused by the ciguatoxins from the dinoflagellate genus Gambierdiscus, however, there is the potential for other toxins such as okadaic acid and dinophysistoxins from the genus Prorocentrum, and palytoxin from the genus Ostreopsis, to contaminate seafood. These genera may also be indicators of ecosystem health and potentially impact on coral reef ecosystems and the role they may play in the succession of coral to macroalgae dominated reefs has not been researched. Sixteen GBR field sites spanning inshore, mid-lagoon and outer lagoon (offshore) regions were studied. Samples were collected from September 2006 to December 2007 and abundance of benthic dinoflagellates on different host macroalgae and concentration of nutrients present in the water column were determined. The maximum abundance of Prorocentrum, Ostreopsis and Gambierdiscus found was 112, 793 and 50 cells per gram wet weight of host macroalgae, respectively. The average level of Dissolved Inorganic Nitrogen (DIN) in the water column across all sites (0.03 mg/L) was found to be more than double the threshold critical value (0.013 mg/L) for healthy coral reefs. Compared to a previous study 1984, there is evidence of a major shift in the distribution and abundance of these dinoflagellates. Inshore reefs have either of Prorocentrum (as at Green Island) or Ostreopsis (as at Magnetic Island) dominating the macroalgal surface niche which was once dominated by Gambierdiscus, whilst at offshore regions Gambierdiscus is still dominant. This succession may be linked to the ongoing eutrophication of the GBR lagoon and have consequences for the sources of toxins for ongoing cases of ciguatera. Published by Elsevier Ltd.

  11. Inferring coastal processes from regional-scale mapping of {sup 222}Radon and salinity: examples from the Great Barrier Reef, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Stieglitz, Thomas C., E-mail: thomas.stieglitz@jcu.edu.a [AIMS-JCU, Townsville (Australia); Australian Institute of Marine Science, PMB NO 3, Townsville QLD 4810 (Australia); School of Engineering and Physical Sciences, James Cook University, Townsville QLD 4811 (Australia); Cook, Peter G., E-mail: peter.g.cook@csiro.a [CSIRO Land and Water, Private Bag 2, Glen Osmond SA 5064 (Australia); Burnett, William C., E-mail: wburnett@mailer.fsu.ed [Department of Oceanography, Florida State University, Tallahassee, FL 32306 (United States)

    2010-07-15

    The radon isotope {sup 222}Rn and salinity in coastal surface water were mapped on regional scales, to improve the understanding of coastal processes and their spatial variability. Radon was measured with a surface-towed, continuously recording multi-detector setup on a moving vessel. Numerous processes and locations of land-ocean interaction along the Central Great Barrier Reef coastline were identified and interpreted based on the data collected. These included riverine fluxes, terrestrially-derived fresh submarine groundwater discharge (SGD) and the tidal pumping of seawater through mangrove forests. Based on variations in the relationship of the tracers radon and salinity, some aspects of regional freshwater inputs to the coastal zone and to estuaries could be assessed. Concurrent mapping of radon and salinity allowed an efficient qualitative assessment of land-ocean interaction on various spatial and temporal scales, indicating that such surveys on coastal scales can be a useful tool to obtain an overview of SGD locations and processes.

  12. Insights into the history and timing of post-European land use disturbance on sedimentation rates in catchments draining to the Great Barrier Reef.

    Science.gov (United States)

    Bartley, Rebecca; Thompson, Chris; Croke, Jacky; Pietsch, Tim; Baker, Brett; Hughes, Kate; Kinsey-Henderson, Anne

    2018-06-01

    Sediment runoff has been cited as a major contributor to the declining health of the Great Barrier Reef (GBR), however, climate and land use drivers have not been jointly evaluated. This study used alluvial archives from fluvial benches in two tributaries of the Upper Burdekin catchment together with the best available land use history and climate proxy records to provide insights into the timing of depositional events in this region over the past 500 years. This study suggests that mining and the increased runoff variability in the latter half of the nineteenth century are the likely sources of the original excess sediment that was used to build the bench features in these catchments. Grazing also contributed to increased bench sedimentation prior to 1900, however, the contribution of grazing was likely more significant in the second half of the 20th century, and continues to be a dominant land use contributor today. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Predictable pollution: an assessment of weather balloons and associated impacts on the marine environment--an example for the Great Barrier Reef, Australia.

    Science.gov (United States)

    O'Shea, Owen R; Hamann, Mark; Smith, Walter; Taylor, Heidi

    2014-02-15

    Efforts to curb pollution in the marine environment are covered by national and international legislation, yet weather balloons are released into the environment with no salvage agenda. Here, we assess impacts associated with weather balloons in the Great Barrier Reef World Heritage Area (GBRWHA). We use modeling to assess the probability of ocean endpoints for released weather balloons and predict pathways post-release. In addition, we use 21 months of data from beach cleanup events to validate our results and assess the abundance and frequency of weather balloon fragments in the GBRWHA. We found between 65% and 70% of balloons land in the ocean and ocean currents largely determine final endpoints. Beach cleanup data revealed 2460 weather balloon fragments were recovered from 24 sites within the GBRWHA. This is the first attempt to quantify this problem and these data will add support to a much-needed mitigation strategy for weather balloon waste. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Sense of place as a determinant of people's attitudes towards the environment: implications for natural resources management and planning in the Great Barrier Reef, Australia.

    Science.gov (United States)

    Larson, Silva; De Freitas, Debora M; Hicks, Christina C

    2013-03-15

    Integrating people's values and perceptions into planning is essential for the successful management of natural resources. However, successful implementation of natural resources management decisions on the ground is a complex task, which requires a comprehensive understanding of a system's social and ecological linkages. This paper investigates the relationship between sense of place and people's attitudes towards their natural environment. Sense of place contributes towards shaping peoples' beliefs, values and commitments. Here, we set out to explore how these theoretical contributions can be operationalized for natural resources management planning in the Great Barrier Reef region of Australia. We hypothesise that the region's diverse range of natural resources, conservation values and management pressures might be reflected in people's attachment to place. To tests this proposition, variables capturing socio-demographics, personal wellbeing and a potential for sense of place were collected via mail-out survey of 372 residents of the region, and tested for relationships using multivariate regression and redundancy orientation analyses. Results indicate that place of residence within the region, involvement in community activities, country of birth and the length of time respondents lived in the region are important determinants of the values assigned to factors related to the natural environment. This type of information is readily available from National Census and thus could be incorporated into the planning of community engagement strategies early in the natural resources management planning process. A better understanding of the characteristics that allow sense of place meanings to develop can facilitate a better understanding of people's perceptions towards environmental and biodiversity issues. We suggest that the insights gained from this study can benefit environmental decision making and planning in the Great Barrier Reef region; and that sense of place

  15. Globally intertwined evolutionary history of giant barrel sponges

    Science.gov (United States)

    Swierts, Thomas; Peijnenburg, Katja T. C. A.; de Leeuw, Christiaan A.; Breeuwer, Johannes A. J.; Cleary, Daniel F. R.; de Voogd, Nicole J.

    2017-09-01

    Three species of giant barrel sponge are currently recognized in two distinct geographic regions, the tropical Atlantic and the Indo-Pacific. In this study, we used molecular techniques to study populations of giant barrel sponges across the globe and assessed whether the genetic structure of these populations agreed with current taxonomic consensus or, in contrast, whether there was evidence of cryptic species. Using molecular data, we assessed whether giant barrel sponges in each oceanic realm represented separate monophyletic lineages. Giant barrel sponges from 17 coral reef systems across the globe were sequenced for mitochondrial (partial CO1 and ATP6 genes) and nuclear (ATPsβ intron) DNA markers. In total, we obtained 395 combined sequences of the mitochondrial CO1 and ATP6 markers, which resulted in 17 different haplotypes. We compared a phylogenetic tree constructed from 285 alleles of the nuclear intron ATPsβ to the 17 mitochondrial haplotypes. Congruent patterns between mitochondrial and nuclear gene trees of giant barrel sponges provided evidence for the existence of multiple reproductively isolated species, particularly where they occurred in sympatry. The species complexes in the tropical Atlantic and the Indo-Pacific, however, do not form separate monophyletic lineages. This rules out the scenario that one species of giant barrel sponge developed into separate species complexes following geographic separation and instead suggests that multiple species of giant barrel sponges already existed prior to the physical separation of the Indo-Pacific and tropical Atlantic.

  16. Benthic meiofaunal community response to the cascading effects of herbivory within an algal halo system of the Great Barrier Reef.

    Science.gov (United States)

    Ollivier, Quinn R; Hammill, Edward; Booth, David J; Madin, Elizabeth M P; Hinchliffe, Charles; Harborne, Alastair R; Lovelock, Catherine E; Macreadie, Peter I; Atwood, Trisha B

    2018-01-01

    Benthic fauna play a crucial role in organic matter decomposition and nutrient cycling at the sediment-water boundary in aquatic ecosystems. In terrestrial systems, grazing herbivores have been shown to influence below-ground communities through alterations to plant distribution and composition, however whether similar cascading effects occur in aquatic systems is unknown. Here, we assess the relationship between benthic invertebrates and above-ground fish grazing across the 'grazing halos' of Heron Island lagoon, Australia. Grazing halos, which occur around patch reefs globally, are caused by removal of seagrass or benthic macroalgae by herbivorous fish that results in distinct bands of unvegetated sediments surrounding patch reefs. We found that benthic algal canopy height significantly increased with distance from patch reef, and that algal canopy height was positively correlated with the abundances of only one invertebrate taxon (Nematoda). Both sediment carbon to nitrogen ratios (C:N) and mean sediment particle size (μm) demonstrated a positive correlation with Nematoda and Arthropoda (predominantly copepod) abundances, respectively. These positive correlations indicate that environmental conditions are a major contributor to benthic invertebrate community distribution, acting on benthic communities in conjunction with the cascading effects of above-ground algal grazing. These results suggest that benthic communities, and the ecosystem functions they perform in this system, may be less responsive to changes in above-ground herbivorous processes than those previously studied in terrestrial systems. Understanding how above-ground organisms, and processes, affect their benthic invertebrate counterparts can shed light on how changes in aquatic communities may affect ecosystem function in previously unknown ways.

  17. Widespread hybridization and bidirectional introgression in sympatric species of coral reef fish

    KAUST Repository

    Harrison, Hugo B.; Berumen, Michael L.; Saenz-Agudelo, Pablo; Salas, Eva; Williamson, David H.; Jones, Geoffrey P.

    2017-01-01

    interspecific hybrids from a collection of 2,991 coral trout sampled in inshore and mid-shelf reefs of the southern Great Barrier Reef. Hybrids were ubiquitous among reefs, fertile and spanned multiple generations suggesting both ecological and evolutionary

  18. The role of marine reserves in the replenishment of a locally-impacted population of anemonefish on the Great Barrier Reef

    KAUST Repository

    Bonin, Mary C.; Harrison, Hugo B.; Williamson, David H.; Frisch, Ashley J.; Saenz Agudelo, Pablo; Berumen, Michael L.; Jones, Geoffrey P.

    2015-01-01

    The development of parentage analysis to track the dispersal of juvenile offspring has given us unprecedented insight into the population dynamics of coral reef fishes. These tools now have the potential to inform fisheries management and species conservation, particularly for small fragmented populations under threat from exploitation and disturbance. In this study we resolve patterns of larval dispersal for a population of the anemonefish Amphiprion melanopus in the Keppel Islands (southern Great Barrier Reef). Habitat loss and fishing appear to have impacted this population and a network of no-take marine reserves currently protects 75% of the potential breeders. Using parentage analysis, we estimate that 21% of recruitment in the island group was generated locally, and that breeding adults living in reserves were responsible for 79% (31 out of 39) of these of locally-produced juveniles. Overall, the network of reserves was fully connected via larval dispersal; however one reserve was identified as a critical source of larvae for the island group. The population in the Keppel Islands also appears to be well-connected to other source populations at least 60 km away, given that 79% (145 out of 184) of the juveniles sampled remained unassigned in the parentage analysis. We estimated the effective size of the A. melanopus metapopulation to be 745 (582-993 95% CI) and recommend continued monitoring of its genetic status. Maintaining connectivity with populations beyond the Keppel Islands and recovery of local recruitment habitat, potentially through active restoration of host anemone populations, will be important for its long-term persistence.

  19. The role of marine reserves in the replenishment of a locally-impacted population of anemonefish on the Great Barrier Reef

    KAUST Repository

    Bonin, Mary C.

    2015-11-21

    The development of parentage analysis to track the dispersal of juvenile offspring has given us unprecedented insight into the population dynamics of coral reef fishes. These tools now have the potential to inform fisheries management and species conservation, particularly for small fragmented populations under threat from exploitation and disturbance. In this study we resolve patterns of larval dispersal for a population of the anemonefish Amphiprion melanopus in the Keppel Islands (southern Great Barrier Reef). Habitat loss and fishing appear to have impacted this population and a network of no-take marine reserves currently protects 75% of the potential breeders. Using parentage analysis, we estimate that 21% of recruitment in the island group was generated locally, and that breeding adults living in reserves were responsible for 79% (31 out of 39) of these of locally-produced juveniles. Overall, the network of reserves was fully connected via larval dispersal; however one reserve was identified as a critical source of larvae for the island group. The population in the Keppel Islands also appears to be well-connected to other source populations at least 60 km away, given that 79% (145 out of 184) of the juveniles sampled remained unassigned in the parentage analysis. We estimated the effective size of the A. melanopus metapopulation to be 745 (582-993 95% CI) and recommend continued monitoring of its genetic status. Maintaining connectivity with populations beyond the Keppel Islands and recovery of local recruitment habitat, potentially through active restoration of host anemone populations, will be important for its long-term persistence.

  20. A Modern Sr/Ca-δ18O-Sea Surface Temperature Calibration for Isopora Corals in the Great Barrier Reef

    Science.gov (United States)

    Brenner, L. D.; Linsley, B. K.; Potts, D. C.

    2014-12-01

    Most coral-based paleoceanographic studies have used massive colonies of Porites or Faviidae, due to their long, continuously accreted skeletal records and sub-annual resolution, but other sub-massive corals provide an untapped resource. The genus Isopora is a dominant reef builder in some high-energy environments in the tropical western Pacific, and was a major component of cores recovered on IODP Leg 325 off the Great Barrier Reef (GBR). Despite its abundance, Isopora remains largely unexplored and hence underutilized in paleoceanographic studies. We present a modern Sr/Ca-δ18O-Sea Surface Temperature (SST) calibration of modern Isopora corals (n=3) collected from inner and outer reef locations ranging from 1-13m depth by Heron Island in the southern GBR in 2012. Pairing the Isopora Sr/Ca record with monthly SST yielded an average relationship of SST=-11.48×(Sr/Ca)+131.1 (r2 = 0.42-0.78). The Sr/Ca sensitivity of -0.087 mmol/mol/°C is similar to the sensitivity for Porites that was corrected for tissue layer smoothing effects determined by Gagan et al. (2012). The similarity between our Sr/Ca-SST sensitivity and the corrected sensitivity for Porites suggests tissue layer effects are minimal in Isopora. The mean annual SST amplitude recorded by the corals from 2008-2011 (full annual cycles) was 5.3°C and the average δ18O annual cycle of 1.1‰ approximates that expected if salinity had little effect on coral δ18O, assuming a previously established conversion of -0.23‰ (δ18O)/°C for biogenic aragonite. The average annual salinity amplitude of 0.3 in gridded data from around Heron Island supports our conclusion that δ18O variability is forced almost completely by SST. This modern Sr/Ca-SST calibration will expand the paleoceanographic utility of Isopora and, by assisting interpretation of Sr/Ca data from fossil corals collected during IODP 325, will better constrain the timing and magnitude of sea level changes and surface conditions since the Last

  1. 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.

  2. Biodiversity of Macrofauna Associated with Sponges across Ecological Gradients in the Central Red Sea

    KAUST Repository

    Kandler, Nora

    2015-12-01

    Between 33 and 91 percent of marine species are currently undescribed, with the majority occurring in tropical and offshore environments. Sponges act as important microhabitats and promote biodiversity by harboring a wide variety of macrofauna and microbiota, but little is known about the relationships between the sponges and their symbionts. This study uses DNA barcoding to examine the macrofaunal communities associated with sponges of the central Saudi Arabian Red Sea, a drastically understudied ecosystem with high biodiversity and endemism. In total, 185 epifaunal and infaunal operational taxonomic units (OTUs) were distinguished from the 1399 successfully-sequenced macrofauna individuals from 129 sponges representing seven sponge species, one of which (Stylissa carteri) was intensively studied. A significant difference was found in the macrofaunal community composition of Stylissa carteri along a cross-shelf gradient using relative OTU abundance (Bray-Curtis diversity index). The abundance of S. carteri also follows a cross-shelf gradient, increasing with proximity to shore. The difference in macrofaunal communities of several species of sponges at one location was found to be significant as well, using OTU presence (binary Jaccard diversity index). Four of the seven sponge species collected were dominated by a single annelid OTU, each unique to one sponge species. A fifth was dominated by four arthropod OTUs, all species-specific as well. Region-based diversity differences may be attributed to environmental factors such as reef morphology, water flow, and sedimentation, whereas species-based differences may be caused by sponge morphology, microbial abundances, and chemical defenses. As climate change and ocean acidification continue to modify coral reef ecosystems, understanding the ecology of sponges and their role as microhabitats may become more important. This thesis also includes a supplemental document in the form of a spreadsheet showing the number of

  3. Sponge cell culture

    NARCIS (Netherlands)

    Schippers, K.J.

    2013-01-01

    Marine sponges are a rich source of bioactive compounds with pharmaceutical potential and are the most prolific source of newly discovered bioactive compounds with more than 7,000 novel molecules discovered in 40 years. Despite its enormous potential, only a few sponge-derived bioactive

  4. COLLABORATIVE GUIDE: A REEF MANAGER'S GUIDE TO ...

    Science.gov (United States)

    Innovative strategies to conserve the world's coral reefs are included in a new guide released today by NOAA, and the Australian Great Barrier Reef Marine Park Authority, with author contributions from a variety of international partners from government agencies, non-governmental organizations, and academic institutions. Referred to as A Reef Manager's Guide to Coral Bleaching, the guide will provide coral reef managers with the latest scientific information on the causes of coral bleaching and new management strategies for responding to this significant threat to coral reef ecosystems. Innovative strategies to conserve the world's coral reefs are included in a new guide released today by NOAA, and the Australian Great Barrier Reef Marine Park Authority, with author contributions from a variety of international partners from government agencies, non-governmental organizations, and academic institutions. Dr. Jordan West, of the National Center for Environmental Assessment, was a major contributor to the guide. Referred to as

  5. Surgical sponges in small animal surgery.

    Science.gov (United States)

    Zeltzman, Phil; Downs, Myron

    2011-06-01

    Sponges are commonly used in veterinary practice. Uses for sponges in the operative arena include hemostasis, retraction, protection, dissection, and general wound management. Blood loss can be quantitated by counting blood-soaked sponges. Complications may arise when sponges are retained in the patient. Sponge retention is a risk whenever sponges are used during surgery, regardless of surgical procedure. This article reviews physical characteristics and proper uses of sponges, complications of sponge retention, and techniques to avoid retained sponges.

  6. Environmental impacts of air-gun surveys on glass sponges : final report

    Energy Technology Data Exchange (ETDEWEB)

    Tunnicliffe, V.; Yahel, G. [Victoria Univ., Victoria, BC (Canada). Dept. of Biology; Chapman, R.; Wilmut, M. [Victoria Univ., Victoria, BC (Canada). School of Earth and Ocean Sciences

    2008-09-15

    Air-gun surveys associated with the oil and gas exploration in the Queen Charlotte Basin will insonify the seafloor with broadband, high intensity noise, exposing the glass sponge reef systems of that area to acoustic impacts. Tissue integrity and behaviour of marine animals can be affected by the acoustic harassment of water propagated vibration. This paper examined the effects of acoustic noise on the behaviour of glass sponges. The purpose of the study was to test the hypothesis that the acoustic vibration produced by a small, surface operated air gun would not alter the normal pattern of sponge feeding activities. The paper described the methods, with particular reference to the study site; sponge pumping rate; and acoustic effects on sponge pumping. Results were presented for ambient conditions; air gun shots; sponge pumping responses to air gun shots; and correlation of sponge response and ambient current. The question of whether the sponge's excurrent flow responds to the pressure from a series of air-gun shots was addressed by a statistical analysis over all the excurrent data from the experiment. It was concluded that there is little or no evidence that the acoustic pressure from the shots influences the physiological functions of the sponge. 22 refs., 2 tabs., 11 figs.

  7. Environmental impacts of air-gun surveys on glass sponges : final report

    Energy Technology Data Exchange (ETDEWEB)

    Tunnicliffe, V; Yahel, G [Victoria Univ., Victoria, BC (Canada). Dept. of Biology; Chapman, R; Wilmut, M [Victoria Univ., Victoria, BC (Canada). School of Earth and Ocean Sciences

    2008-09-15

    Air-gun surveys associated with the oil and gas exploration in the Queen Charlotte Basin will insonify the seafloor with broadband, high intensity noise, exposing the glass sponge reef systems of that area to acoustic impacts. Tissue integrity and behaviour of marine animals can be affected by the acoustic harassment of water propagated vibration. This paper examined the effects of acoustic noise on the behaviour of glass sponges. The purpose of the study was to test the hypothesis that the acoustic vibration produced by a small, surface operated air gun would not alter the normal pattern of sponge feeding activities. The paper described the methods, with particular reference to the study site; sponge pumping rate; and acoustic effects on sponge pumping. Results were presented for ambient conditions; air gun shots; sponge pumping responses to air gun shots; and correlation of sponge response and ambient current. The question of whether the sponge's excurrent flow responds to the pressure from a series of air-gun shots was addressed by a statistical analysis over all the excurrent data from the experiment. It was concluded that there is little or no evidence that the acoustic pressure from the shots influences the physiological functions of the sponge. 22 refs., 2 tabs., 11 figs.

  8. The Australian REEFREP System: A Coastal Vessel Traffic Information Service and Ship Reporting System for the Torres Strait Region and the Inner Route of the Great Barrier Reef

    Science.gov (United States)

    MacDonald, John C.

    The new Australian ship reporting system, identifier , will be the core component of a Vessel Traffic Information Service (VTIS) covering the Torres Strait region and the Great Barrier Reef (GBR). It is the first such system to be considered by the International Maritime Organization (IMO) under the terms of the new SOLAS 74 regulation v/8-1, which entered into force on 1 January 1996 and allows for ship reporting systems adopted by the Organization to be made mandatory for all, or certain categories of vessels.The REEFREP system, planned for implementation on 1 January 1997, extends for some 900 n.m. or about 1500 km along the Queensland coastline. It will be a VHF radio-based system with radars covering three selected focal points in the Torres Strait, off Cairns and in the southern approaches to the inner route. The system will provide a capability for a single Ship Reporting Centre to interact with shipping, enabling the provision of improved information on the presence, movements and patterns of shipping in the area and the ability to respond more quickly to an incident or pollution should this occur.An interesting feature and a major factor in the system design is the remoteness of most equipment sites and the limited infrastructure available to support communications and data transmission requiring the application of advanced technology and video transmission, solar power generation and software engineering skills of a high order.

  9. Phylogeography of the reef fish Cephalopholis argus (Epinephelidae indicates Pleistocene isolation across the indo-pacific barrier with contemporary overlap in the coral triangle

    Directory of Open Access Journals (Sweden)

    Gomez Juan A

    2011-07-01

    Full Text Available Abstract Background The Coral Triangle (CT, bounded by the Philippines, the Malay Peninsula, and New Guinea, is the epicenter of marine biodiversity. Hypotheses that explain the source of this rich biodiversity include 1 the center of origin, 2 the center of accumulation, and 3 the region of overlap. Here we contribute to the debate with a phylogeographic survey of a widely distributed reef fish, the Peacock Grouper (Cephalopholis argus; Epinephelidae at 21 locations (N = 550 using DNA sequence data from mtDNA cytochrome b and two nuclear introns (gonadotropin-releasing hormone and S7 ribosomal protein. Results Population structure was significant (ΦST = 0.297, P FST = 0.078, P FST = 0.099, P P = 0.001 and the combined nuclear loci (r = 0.715, P d = 0.008, corresponding to the Pacific and Indian Oceans, with a low level of introgression observed outside a mixing zone at the Pacific-Indian boundary. Conclusions We conclude that the Indo-Pacific Barrier, operating during low sea level associated with glaciation, defines the primary phylogeographic pattern in this species. These data support a scenario of isolation on the scale of 105 year glacial cycles, followed by population expansion toward the CT, and overlap of divergent lineages at the Pacific-Indian boundary. This pattern of isolation, divergence, and subsequent overlap likely contributes to species richness at the adjacent CT and is consistent with the region of overlap hypothesis.

  10. Comparison of retracked coastal altimetry sea levels against high frequency radar on the continental shelf of the Great Barrier Reef, Australia

    Science.gov (United States)

    Idris, Nurul Hazrina; Deng, Xiaoli; Idris, Nurul Hawani

    2017-07-01

    Comparison of Jason-1 altimetry retracked sea levels and high frequency (HF) radar velocity is examined within the region of the Great Barrier Reef, Australia. The comparison between both datasets is not direct because the altimetry derives only the geostrophic component, while the HF radar velocity includes information on both geostrophic and ageostrophic components, such as tides and winds. The comparison of altimetry and HF radar data is performed based on the parameter of surface velocity inferred from both datasets. The results show that 48% (10 out of 21 cases) of data have high (≥0.5) spatial correlation. The mean of spatial correlation for all 21 cases is 0.43. This value is within the range (0.42 to 0.5) observed by other studies. Low correlation is observed due to disagreement in the trend of velocity signals in which sometimes they have contradictions in the signal direction and the position of the peak is shifted. In terms of standard deviation of difference and root mean square error, both datasets show reasonable agreement with ≤2.5 cm s-1.

  11. Zooxanthellar symbionts shape host sponge trophic status through translocation of carbon.

    Science.gov (United States)

    Weisz, Jeremy B; Massaro, Andrew J; Ramsby, Blake D; Hill, Malcolm S

    2010-12-01

    Sponges belonging to the genus Cliona are common inhabitants of many coral reefs, and as bioeroders, they play an important role in the carbonate cycle of the reef. Several Cliona species maintain intracellular populations of dinoflagellate zooxanthellae (i.e., Symbiodinium spp.), which also form symbioses with a variety of other invertebrates and protists (e.g., corals, molluscs, foraminifera). Unlike the case of coral symbioses, however, almost nothing is known of the metabolic interaction between sponges and their zooxanthella symbionts. To assess this interaction, we performed a tracer experiment to follow C and N in the system, performed a reciprocal transplant experiment, and measured the stable carbon isotope ratio of Cliona spp. with and without zooxanthellae to study the influence of environment on the interaction. We found strong evidence of a transfer of C from zooxanthellae to their sponge hosts but no evidence of a transfer of N from sponge to zooxanthellae. We also saw significant influences of the environment on the metabolism of the sponges. Finally, we observed significant differences in carbon metabolism of sponge species with and without symbionts. These data strongly support hypotheses of metabolic integration between zooxanthellae and their sponge host and extend our understanding of basic aspects of benthic-pelagic coupling in shallow-water marine environments.

  12. A modern Sr/Ca-δ18O-sea surface temperature calibration for Isopora corals on the Great Barrier Reef

    Science.gov (United States)

    Brenner, Logan D.; Linsley, Braddock K.; Potts, Donald C.

    2017-02-01

    Isopora (Acroporidae) is a genus of often encrusting, branching to submassive corals that are common in many shallow habitats on modern and fossil Indo-West Pacific reefs. Although abundant, Isopora is largely absent from paleoceanographic literature. The scarcity of large Porites and the abundance of Isopora retrieved from the Great Barrier Reef (GBR) on Integrated Ocean Drilling Program Expedition 325 focused paleoceanographic attention on Isopora. Here we provide the first independent high-resolution calibration of both Sr/Ca and δ18O for temperature analyses based on Isopora and demonstrate its consistency with Porites records. We developed modern skeletal Sr/Ca- and δ18O-sea surface temperature (SST) calibrations based on five modern Isopora colonies from Heron Island in the southern GBR. Pairing the coral Sr/Ca record with monthly SST data yielded Sr/Ca-SST sensitivities from -0.061 ± 0.004 (centered) to -0.083 ± 0.007 (raw) mmol/mol °C-1 based on reduced major axis regressions. These sensitivities are in the middle of the range of published Porites values and overlap most published values for Isopora, -0.075 ± 0.011 to -0.065 ± 0.011 mmol/mol °C-1. The δ18O-SST sensitivities range from -0.184 ± 0.014 (centered) to -0.185 ± 0.014 (raw) ‰ °C-1, assuming that all seasonal variation in δ18O was due to SST. These δ18O-SST sensitivities are smaller than the widely accepted value of -0.23‰ °C-1 for biogenic aragonite but are at the upper end of high-resolution Porites-defined sensitivities that are consistently less than the aforementioned established value. Our results validate the use of Isopora as an alternative source of paleoceanographic records in habitats where large massive Porites are scarce or absent.

  13. The sponge microbiome project

    KAUST Repository

    Moitinho-Silva, Lucas; Nielsen, Shaun; Amir, Amnon; Gonzalez, Antonio; Ackermann, Gail L.; Cerrano, Carlo; Astudillo-Garcia, Carmen; Easson, Cole; Sipkema, Detmer; Liu, Fang; Steinert, Georg; Kotoulas, Giorgos; McCormack, Grace P.; Feng, Guofang; Bell, James J.; Vicente, Jan; Bjö rk, Johannes R.; Montoya, Jose M.; Olson, Julie B.; Reveillaud, Julie; Steindler, Laura; Pineda, Mari-Carmen; Marra, Maria V.; Ilan, Micha; Taylor, Michael W.; Polymenakou, Paraskevi; Erwin, Patrick M.; Schupp, Peter J.; Simister, Rachel L.; Knight, Rob; Thacker, Robert W.; Costa, Rodrigo; Hill, Russell T.; Lopez-Legentil, Susanna; Dailianis, Thanos; Ravasi, Timothy; Hentschel, Ute; Li, Zhiyong; Webster, Nicole S.; Thomas, Torsten

    2017-01-01

    Marine sponges (phylum Porifera) are a diverse, phylogenetically deep-branching clade known for forming intimate partnerships with complex communities of microorganisms. To date, 16S rRNA gene sequencing studies have largely utilised different

  14. The sponge microbiome project.

    Science.gov (United States)

    Moitinho-Silva, Lucas; Nielsen, Shaun; Amir, Amnon; Gonzalez, Antonio; Ackermann, Gail L; Cerrano, Carlo; Astudillo-Garcia, Carmen; Easson, Cole; Sipkema, Detmer; Liu, Fang; Steinert, Georg; Kotoulas, Giorgos; McCormack, Grace P; Feng, Guofang; Bell, James J; Vicente, Jan; Björk, Johannes R; Montoya, Jose M; Olson, Julie B; Reveillaud, Julie; Steindler, Laura; Pineda, Mari-Carmen; Marra, Maria V; Ilan, Micha; Taylor, Michael W; Polymenakou, Paraskevi; Erwin, Patrick M; Schupp, Peter J; Simister, Rachel L; Knight, Rob; Thacker, Robert W; Costa, Rodrigo; Hill, Russell T; Lopez-Legentil, Susanna; Dailianis, Thanos; Ravasi, Timothy; Hentschel, Ute; Li, Zhiyong; Webster, Nicole S; Thomas, Torsten

    2017-10-01

    Marine sponges (phylum Porifera) are a diverse, phylogenetically deep-branching clade known for forming intimate partnerships with complex communities of microorganisms. To date, 16S rRNA gene sequencing studies have largely utilised different extraction and amplification methodologies to target the microbial communities of a limited number of sponge species, severely limiting comparative analyses of sponge microbial diversity and structure. Here, we provide an extensive and standardised dataset that will facilitate sponge microbiome comparisons across large spatial, temporal, and environmental scales. Samples from marine sponges (n = 3569 specimens), seawater (n = 370), marine sediments (n = 65) and other environments (n = 29) were collected from different locations across the globe. This dataset incorporates at least 268 different sponge species, including several yet unidentified taxa. The V4 region of the 16S rRNA gene was amplified and sequenced from extracted DNA using standardised procedures. Raw sequences (total of 1.1 billion sequences) were processed and clustered with (i) a standard protocol using QIIME closed-reference picking resulting in 39 543 operational taxonomic units (OTU) at 97% sequence identity, (ii) a de novo clustering using Mothur resulting in 518 246 OTUs, and (iii) a new high-resolution Deblur protocol resulting in 83 908 unique bacterial sequences. Abundance tables, representative sequences, taxonomic classifications, and metadata are provided. This dataset represents a comprehensive resource of sponge-associated microbial communities based on 16S rRNA gene sequences that can be used to address overarching hypotheses regarding host-associated prokaryotes, including host specificity, convergent evolution, environmental drivers of microbiome structure, and the sponge-associated rare biosphere. © The Authors 2017. Published by Oxford University Press.

  15. The sponge microbiome project

    KAUST Repository

    Moitinho-Silva, Lucas

    2017-08-16

    Marine sponges (phylum Porifera) are a diverse, phylogenetically deep-branching clade known for forming intimate partnerships with complex communities of microorganisms. To date, 16S rRNA gene sequencing studies have largely utilised different extraction and amplification methodologies to target the microbial communities of a limited number of sponge species, severely limiting comparative analyses of sponge microbial diversity and structure. Here, we provide an extensive and standardised dataset that will facilitate sponge microbiome comparisons across large spatial, temporal, and environmental scales. Samples from marine sponges (n = 3569 specimens), seawater (n = 370), marine sediments (n = 65) and other environments (n = 29) were collected from different locations across the globe. This dataset incorporates at least 268 different sponge species, including several yet unidentified taxa. The V4 region of the 16S rRNA gene was amplified and sequenced from extracted DNA using standardised procedures. Raw sequences (total of 1.1 billion sequences) were processed and clustered with (i) a standard protocol using QIIME closed-reference picking resulting in 39 543 operational taxonomic units (OTU) at 97% sequence identity, (ii) a de novo clustering using Mothur resulting in 518 246 OTUs, and (iii) a new high-resolution Deblur protocol resulting in 83 908 unique bacterial sequences. Abundance tables, representative sequences, taxonomic classifications, and metadata are provided. This dataset represents a comprehensive resource of sponge-associated microbial communities based on 16S rRNA gene sequences that can be used to address overarching hypotheses regarding host-associated prokaryotes, including host specificity, convergent evolution, environmental drivers of microbiome structure, and the sponge-associated rare biosphere.

  16. Pyrosequencing of bacterial symbionts within Axinella corrugata sponges: diversity and seasonal variability.

    Directory of Open Access Journals (Sweden)

    James R White

    Full Text Available BACKGROUND: Marine sponge species are of significant interest to many scientific fields including marine ecology, conservation biology, genetics, host-microbe symbiosis and pharmacology. One of the most intriguing aspects of the sponge "holobiont" system is the unique physiology, interaction with microbes from the marine environment and the development of a complex commensal microbial community. However, intraspecific variability and temporal stability of sponge-associated bacterial symbionts remain relatively unknown. METHODOLOGY/PRINCIPAL FINDINGS: We have characterized the bacterial symbiont community biodiversity of seven different individuals of the Caribbean reef sponge Axinella corrugata, from two different Florida reef locations during variable seasons using multiplex 454 pyrosequencing of 16 S rRNA amplicons. Over 265,512 high-quality 16 S rRNA sequences were generated and analyzed. Utilizing versatile bioinformatics methods and analytical software such as the QIIME and CloVR packages, we have identified 9,444 distinct bacterial operational taxonomic units (OTUs. Approximately 65,550 rRNA sequences (24% could not be matched to bacteria at the class level, and may therefore represent novel taxa. Differentially abundant classes between seasonal Axinella communities included Gammaproteobacteria, Flavobacteria, Alphaproteobacteria, Cyanobacteria, Acidobacter and Nitrospira. Comparisons with a proximal outgroup sponge species (Amphimedon compressa, and the growing sponge symbiont literature, indicate that this study has identified approximately 330 A. corrugata-specific symbiotic OTUs, many of which are related to the sulfur-oxidizing Ectothiorhodospiraceae. This family appeared exclusively within A. corrugata, comprising >34.5% of all sequenced amplicons. Other A. corrugata symbionts such as Deltaproteobacteria, Bdellovibrio, and Thiocystis among many others are described. CONCLUSIONS/SIGNIFICANCE: Slight shifts in several bacterial taxa

  17. Phylogeography of the reef fish Cephalopholis argus (Epinephelidae) indicates Pleistocene isolation across the Indo-Pacific Barrier with contemporary overlap in The Coral Triangle.

    Science.gov (United States)

    Gaither, Michelle R; Bowen, Brian W; Bordenave, Tiana-Rae; Rocha, Luiz A; Newman, Stephen J; Gomez, Juan A; van Herwerden, Lynne; Craig, Matthew T

    2011-07-01

    The Coral Triangle (CT), bounded by the Philippines, the Malay Peninsula, and New Guinea, is the epicenter of marine biodiversity. Hypotheses that explain the source of this rich biodiversity include 1) the center of origin, 2) the center of accumulation, and 3) the region of overlap. Here we contribute to the debate with a phylogeographic survey of a widely distributed reef fish, the Peacock Grouper (Cephalopholis argus; Epinephelidae) at 21 locations (N = 550) using DNA sequence data from mtDNA cytochrome b and two nuclear introns (gonadotropin-releasing hormone and S7 ribosomal protein). Population structure was significant (ΦST = 0.297, P Pacific (Line Islands to northeastern Australia), Indo-Pacific boundary (Bali and Rowley Shoals), eastern Indian Ocean (Cocos/Keeling and Christmas Island), and western Indian Ocean (Diego Garcia, Oman, and Seychelles). A strong signal of isolation by distance was detected in both mtDNA (r = 0.749, P = 0.001) and the combined nuclear loci (r = 0.715, P Pacific and Indian Oceans, with a low level of introgression observed outside a mixing zone at the Pacific-Indian boundary. We conclude that the Indo-Pacific Barrier, operating during low sea level associated with glaciation, defines the primary phylogeographic pattern in this species. These data support a scenario of isolation on the scale of 105 year glacial cycles, followed by population expansion toward the CT, and overlap of divergent lineages at the Pacific-Indian boundary. This pattern of isolation, divergence, and subsequent overlap likely contributes to species richness at the adjacent CT and is consistent with the region of overlap hypothesis.

  18. Non-targeted, high resolution mass spectrometry strategy for simultaneous monitoring of xenobiotics and endogenous compounds in green sea turtles on the Great Barrier Reef.

    Science.gov (United States)

    Heffernan, Amy L; Gómez-Ramos, Maria M; Gaus, Caroline; Vijayasarathy, Soumini; Bell, Ian; Hof, Christine; Mueller, Jochen F; Gómez-Ramos, Maria J

    2017-12-01

    Chemical contamination poses a threat to ecosystem, biota and human health, and identifying these hazards is a complex challenge. Traditional hazard identification relies on a priori-defined targets of limited chemical scope, and is generally inappropriate for exploratory studies such as explaining toxicological effects in environmental systems. Here we present a non-target high resolution mass spectrometry environmental monitoring study with multivariate statistical analysis to simultaneously detect biomarkers of exposure (e.g. xenobiotics) and biomarkers of effect in whole turtle blood. Borrowing the concept from clinical chemistry, a case-control sampling approach was used to investigate the potential influence of xenobiotics of anthropogenic origin on free-ranging green sea turtles (Chelonia mydas) from a remote, offshore 'control' site; and two coastal 'case' sites influenced by urban/industrial and agricultural activities, respectively, on the Great Barrier Reef in North Queensland, Australia. Multiple biomarkers of exposure, including sulfonic acids (n=9), a carbamate insecticide metabolite, and other industrial chemicals; and five biomarkers of effect (lipid peroxidation products), were detected in case sites. Additionally, two endogenous biomarkers of neuroinflammation and oxidative stress were identified, and showed moderate-to-strong correlations with clinical measures of inflammation and liver dysfunction. Our data filtering strategy overcomes limitations of traditional a priori selection of target compounds, and adds to the limited environmental xenobiotic metabolomics literature. To our knowledge this is the first case-control study of xenobiotics in marine megafauna, and demonstrates the utility of green sea turtles to link internal and external exposure, to explain potential toxicological effects in environmental systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Sponge cell culture? A molecular identification method for sponge cells

    NARCIS (Netherlands)

    Sipkema, D.; Heilig, G.H.J.; Akkermans, A.D.L.; Osinga, R.; Tramper, J.; Wijffels, R.H.

    2003-01-01

    Dissociated sponge cells are easily confused with unicellular organisms. This has been an obstacle in the development of sponge-cell lines. We developed a molecular detection method to identify cells of the sponge Dysidea avara in dissociated cell cultures. The 18S ribosomal RNA gene from a Dysidea

  20. Sponge Farming Trials: Survival, Attachment, and Growth of Two Indo-Pacific Sponges, Neopetrosia sp. and Stylissa massa

    Directory of Open Access Journals (Sweden)

    Karin Schiefenhövel

    2012-01-01

    Full Text Available Sponges, an important part of the reef ecosystem, are of commercial value for public aquaria, pharmacology and chemistry. With the growing demand for sponges, natural resources are at risk of being overexploited. Growing of sponges in artificial or semi natural farms is an alternative. In this study different farming methods were tested on two Indo-Pacific sponge species, Neopetrosia sp. and Stylissa massa. Survival, growth and attachment ability were observed with different substrates (suspended ropes, coral boulders and artificial substrate, two types of aquaria with different water volume and two different field sites in Indonesia. The two species responded differently to their individual locations and environmental stresses. Survival, growth and attachment rates of Neopetrosia sp. at the field site are depending on the cultivation method, we found highest volume increment (27–35% for a horizontal line in the field. Whereas the volume increase for S. massa did not show any differences for the different transplantation methods, Neopetrosia sp. generally showed higher rates than S. massa. Further aquaria experiments, for example, on nutrient supply, should be tested to receive more detailed data about sponges, particularly because almost all fragments of both species showed a decline or steady state in mean length.

  1. Sponge erosion under acidification and warming scenarios: differential impacts on living and dead coral.

    Science.gov (United States)

    Stubler, Amber D; Furman, Bradley T; Peterson, Bradley J

    2015-11-01

    Ocean acidification will disproportionately impact the growth of calcifying organisms in coral reef ecosystems. Simultaneously, sponge bioerosion rates have been shown to increase as seawater pH decreases. We conducted a 20-week experiment that included a 4-week acclimation period with a high number of replicate tanks and a fully orthogonal design with two levels of temperature (ambient and +1 °C), three levels of pH (8.1, 7.8, and 7.6), and two levels of boring sponge (Cliona varians, present and absent) to account for differences in sponge attachment and carbonate change for both living and dead coral substrate (Porites furcata). Net coral calcification, net dissolution/bioerosion, coral and sponge survival, sponge attachment, and sponge symbiont health were evaluated. Additionally, we used the empirical data from the experiment to develop a stochastic simulation of carbonate change for small coral clusters (i.e., simulated reefs). Our findings suggest differential impacts of temperature, pH and sponge presence for living and dead corals. Net coral calcification (mg CaCO3  cm(-2)  day(-1) ) was significantly reduced in treatments with increased temperature (+1 °C) and when sponges were present; acidification had no significant effect on coral calcification. Net dissolution of dead coral was primarily driven by pH, regardless of sponge presence or seawater temperature. A reevaluation of the current paradigm of coral carbonate change under future acidification and warming scenarios should include ecologically relevant timescales, species interactions, and community organization to more accurately predict ecosystem-level response to future conditions. © 2015 John Wiley & Sons Ltd.

  2. Growth and metabolism of sponges

    NARCIS (Netherlands)

    Koopmans, M.

    2009-01-01

    Sponges (phylum Porifera) are multi cellular filter-feeding invertebrate animals living attached to a substratum in mostly marine but also in freshwater habitats. The interest in sponges has increased rapidly since the discovery of potential new pharmaceutical compounds produced by many sponges. An

  3. Retained surgical sponge

    International Nuclear Information System (INIS)

    Koyama, Masashi; Kurono, Kenji; Iida, Akihiko; Suzuki, Hirochika; Hara, Masaki; Mizutani, Hirokazu; Ohba, Satoru; Mizutani, Masaru; Nakajima, Yoichiro.

    1993-01-01

    The CT, US, and MRI findings of confirmed retained surgical sponges were reviewed. The CT examinations in eight lesions demonstrated round or oval masses with heterogeneous internal structures. The US examinations in 5 lesions demonstrated low echogenic masses with high echogenic internal structures, which suggested retained surgical sponges. MR imagings in three lesions showed slightly high intensity comparable to that of muscles on T1-weighted images and high signal intensity on T2-weighted images, suggesting fluid collections of high protein concentration. (author)

  4. The role of burrowing sponges in bioerosion.

    Science.gov (United States)

    Rützler, Klaus

    1975-09-01

    Among the large number of limestone-eroding organisms, sponges, mainly of the family Clinonidae are of special interest because of their efficient means of substratum penetration by cellular etching and because they release characteristically shaped calcium carbonate chips which can be detected in the mud-size fraction of many sediments. Identifiable trace fossils and sediments are of great ecological and paleoecological significance.As new data on the excavating mechanism have become available, the questions of burrowing rates and sediment production have gained importance. Extrapolation from shortterm experiments (under 6 months) on substrate invasion are inconclusive because of high initial penetration rates resulting from mechanical stimulation and lack of competition. New experiments show that the rate curve flattens after 6 months and that optimum longterm erosion of CaCO 3 does not exceed 700 mg m -2 year -1 (Cliona lampa and C. aprica). Substrate limitations and competition will further reduce this rate.By monitoring the production of CaCO 3 chips by Cliona lampa, it was possible to link activity patterns to certain environmental factors. Mechanical stimuli, high light intensity, strong currents and, possibly, low temperature seem to accelerate the burrowing process. Sponge-generated chips can make up over 40% of coral mud when deposited in the current shadow of the reef framework.Using transect counts and sponge area-biomass conversion factors, the mean abundance of burrowing sponges on the Bermuda platform could be calculated. On suitable hard bottom substrates it averages 16 g dry weight per m 2 . From this value the burrowing potential of sponges can be estimated as 256 g CaCO 3 per m 2 substrate per year. Since 97-98% of the eroded limestone remains in particulate form, the contribution of fine sediments can amount to 250 g m -2 year -1 .Attention is called to the fact that erosion rates by burrowers can not directly be compared with those of borers or

  5. Sediment impacts on marine sponges.

    Science.gov (United States)

    Bell, James J; McGrath, Emily; Biggerstaff, Andrew; Bates, Tracey; Bennett, Holly; Marlow, Joseph; Shaffer, Megan

    2015-05-15

    Changes in sediment input to marine systems can influence benthic environments in many ways. Sponges are important components of benthic ecosystems world-wide and as sessile suspension feeders are likely to be impacted by changes in sediment levels. Despite this, little is known about how sponges respond to changes in settled and suspended sediment. Here we review the known impacts of sedimentation on sponges and their adaptive capabilities, whilst highlighting gaps in our understanding of sediment impacts on sponges. Although the literature clearly shows that sponges are influenced by sediment in a variety of ways, most studies confer that sponges are able to tolerate, and in some cases thrive, in sedimented environments. Critical gaps exist in our understanding of the physiological responses of sponges to sediment, adaptive mechanisms, tolerance limits, and the particularly the effect of sediment on early life history stages. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Artificial Reefs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block...

  7. The Sponge Hologenome

    Science.gov (United States)

    Thomas, Torsten

    2016-01-01

    ABSTRACT A paradigm shift has recently transformed the field of biological science; molecular advances have revealed how fundamentally important microorganisms are to many aspects of a host’s phenotype and evolution. In the process, an era of “holobiont” research has emerged to investigate the intricate network of interactions between a host and its symbiotic microbial consortia. Marine sponges are early-diverging metazoa known for hosting dense, specific, and often highly diverse microbial communities. Here we synthesize current thoughts about the environmental and evolutionary forces that influence the diversity, specificity, and distribution of microbial symbionts within the sponge holobiont, explore the physiological pathways that contribute to holobiont function, and describe the molecular mechanisms that underpin the establishment and maintenance of these symbiotic partnerships. The collective genomes of the sponge holobiont form the sponge hologenome, and we highlight how the forces that define a sponge’s phenotype in fact act on the genomic interplay between the different components of the holobiont. PMID:27103626

  8. Generalized Morphology using Sponges

    NARCIS (Netherlands)

    van de Gronde, Jasper J.; Roerdink, Jos B.T.M.

    2016-01-01

    Mathematical morphology has traditionally been grounded in lattice theory. For non-scalar data lattices often prove too restrictive, however. In this paper we present a more general alternative, sponges, that still allows useful definitions of various properties and concepts from morphological

  9. The sponge microbiome project

    NARCIS (Netherlands)

    Moitinho-Silva, Lucas; Nielsen, Shaun; Amir, Amnon; Gonzalez, Antonio; Ackermann, Gail L.; Cerrano, Carlo; Astudillo-Garcia, Carmen; Easson, Cole; Sipkema, Detmer; Liu, Fang; Steinert, Georg; Kotoulas, Giorgos; McCormack, Grace P.; Feng, Guofang; Bell, James J.; Vicente, Jan; Björk, Johannes R.; Montoya, Jose M.; Olson, Julie B.; Reveillaud, Julie; Steindler, Laura; Pineda, Mari Carmen; Marra, Maria V.; Ilan, Micha; Taylor, Michael W.; Polymenakou, Paraskevi; Erwin, Patrick M.; Schupp, Peter J.; Simister, Rachel L.; Knight, Rob; Thacker, Robert W.; Costa, Rodrigo; Hill, Russell T.; Lopez-Legentil, Susanna; Dailianis, Thanos; Ravasi, Timothy; Hentschel, Ute; Li, Zhiyong; Webster, Nicole S.; Thomas, Torsten

    2017-01-01

    Marine sponges (phylum Porifera) are a diverse, phylogenetically deep-branching clade known for forming intimate partnerships with complex communities of microorganisms. To date, 16S rRNA gene sequencing studies have largely utilised different extraction and amplification methodologies to target the

  10. Genetics Home Reference: white sponge nevus

    Science.gov (United States)

    ... Twitter Home Health Conditions White sponge nevus White sponge nevus Printable PDF Open All Close All Enable ... to view the expand/collapse boxes. Description White sponge nevus is a condition characterized by the formation ...

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

    NARCIS (Netherlands)

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

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

  12. Who's there? - First morphological and DNA barcoding catalogue of the shallow Hawai'ian sponge fauna.

    Science.gov (United States)

    Núñez Pons, Laura; Calcinai, Barbara; Gates, Ruth D

    2017-01-01

    The sponge fauna has been largely overlooked in the Archipelago of Hawai'i, notwithstanding the paramount role of this taxon in marine ecosystems. The lack of knowledge about Porifera populations inhabiting the Hawai'ian reefs limits the development of ecological studies aimed at understanding the functioning of these marine systems. Consequently, this project addresses this gap by describing the most representative sponge species in the shallow waters of the enigmatic bay of Kane'ohe Bay, in O'ahu Island. A total of 30 species (28 demosponges and two calcareous sponges) living associated to the reef structures are here reported. Six of these species are new records to the Hawai'ian Porifera catalogue and are suspected to be recent introductions to these islands. Morphological descriptions of the voucher specimens are provided, along with sequencing data of two partitions involving the mitochondrial cytochrome oxidase subunit 1 (COI) marker and a fragment covering partial (18S and 28S) and full (ITS-1, 5.8S and ITS-2) nuclear ribosomal genes. Species delimitations based on genetic distances were calculated to valitate how taxonomic assignments from DNA barcoding aligned with morphological identifications. Of the 60 sequences submitted to GenBank ~88% are the first sequencing records for the corresponding species and genetic marker. This work compiles the first catalogue combining morphological characters with DNA barcoding of Hawai'ian sponges, and contributes to the repository of public databases through the Sponge Barcoding Project initiative.

  13. Who's there? - First morphological and DNA barcoding catalogue of the shallow Hawai'ian sponge fauna.

    Directory of Open Access Journals (Sweden)

    Laura Núñez Pons

    Full Text Available The sponge fauna has been largely overlooked in the Archipelago of Hawai'i, notwithstanding the paramount role of this taxon in marine ecosystems. The lack of knowledge about Porifera populations inhabiting the Hawai'ian reefs limits the development of ecological studies aimed at understanding the functioning of these marine systems. Consequently, this project addresses this gap by describing the most representative sponge species in the shallow waters of the enigmatic bay of Kane'ohe Bay, in O'ahu Island. A total of 30 species (28 demosponges and two calcareous sponges living associated to the reef structures are here reported. Six of these species are new records to the Hawai'ian Porifera catalogue and are suspected to be recent introductions to these islands. Morphological descriptions of the voucher specimens are provided, along with sequencing data of two partitions involving the mitochondrial cytochrome oxidase subunit 1 (COI marker and a fragment covering partial (18S and 28S and full (ITS-1, 5.8S and ITS-2 nuclear ribosomal genes. Species delimitations based on genetic distances were calculated to valitate how taxonomic assignments from DNA barcoding aligned with morphological identifications. Of the 60 sequences submitted to GenBank ~88% are the first sequencing records for the corresponding species and genetic marker. This work compiles the first catalogue combining morphological characters with DNA barcoding of Hawai'ian sponges, and contributes to the repository of public databases through the Sponge Barcoding Project initiative.

  14. Transcriptional activity of the giant barrel sponge, Xestospongia muta Holobiont: Molecular Evidence for Metabolic Interchange

    Directory of Open Access Journals (Sweden)

    Cara L Fiore

    2015-04-01

    Full Text Available Compared to our understanding of the taxonomic composition of the symbiotic microbes in marine sponges, the functional diversity of these symbionts is largely unknown. Furthermore, the application of genomic, transcriptomic, and proteomic techniques to functional questions on sponge host-symbiont interactions is in its infancy. In this study, we generated a transcriptome for the host and a metatranscriptome of its microbial symbionts for the giant barrel sponge, Xestospongia muta, from the Caribbean. In combination with a gene-specific approach, our goals were to 1 characterize genetic evidence for nitrogen cycling in X. muta, an important limiting nutrient on coral reefs 2 identify which prokaryotic symbiont lineages are metabolically active and, 3 characterize the metabolic potential of the prokaryotic community. Xestospongia muta expresses genes from multiple nitrogen transformation pathways that when combined with the abundance of this sponge, and previous data on dissolved inorganic nitrogen fluxes, shows that this sponge is an important contributor to nitrogen cycling on coral reefs. Additionally, we observed significant differences in gene expression of the archaeal amoA gene, which is involved in ammonia oxidation, between coral reef locations consistent with differences in the fluxes of dissolved inorganic nitrogen previously reported. In regards to symbiont metabolic potential, the genes in the biosynthetic pathways of several amino acids were present in the prokaryotic metatranscriptome dataset but in the host-derived transcripts only the catabolic reactions for these amino acids were present. A similar pattern was observed for the B vitamins (riboflavin, biotin, thiamin, cobalamin. These results expand our understanding of biogeochemical cycling in sponges, and the metabolic interchange highlighted here advances the field of symbiont physiology by elucidating specific metabolic pathways where there is high potential for host

  15. Land-use effects on fluxes of suspended sediment, nitrogen and phosphorus from a river catchment of the Great Barrier Reef, Australia

    Science.gov (United States)

    Hunter, Heather M.; Walton, Richard S.

    2008-07-01

    SummaryA 6-year study was conducted in the Johnstone River system in the wet tropics of north-eastern Australia, to address concerns that the Great Barrier Reef is at risk from elevated levels of suspended sediment (SS) and nutrients discharged from its river catchments. Aims were to quantify: (i) fluxes of SS, phosphorus (P) and nitrogen (N) exported annually from the catchment and (ii) the influence of rural land uses on these fluxes. Around 55% of the 1602 km2 catchment was native rainforest, with the reminder developed mainly for livestock and crop production. Water quality and stream flow were monitored at 16 sites, with the emphasis on sampling major runoff events. Monitoring data were used to calibrate a water quality model for the catchment (HSPF), which was run with 39 years of historical precipitation and evaporation data. Modelled specific fluxes from the catchment of 1.2 ± 1.1 t SS ha-1 y-1, 2.2 ± 1.8 kg P ha-1 y-1 and 11.4 ± 7.3 kg N ha-1y-1 were highly variable between and within years. Fluxes of SS and P were strongly dominated by major events, with 91% of SS and 84% of P exported during the highest 10% of daily flows. On average, sediment P comprised 81% of the total P flux. The N flux was less strongly dominated by major events and sediment N comprised 46% of total N exports. Specific fluxes of SS, N and P from areas receiving precipitation of 3545 mm y-1 were around 3-4 times those from areas receiving 1673 mm y-1. For a given mean annual precipitation, specific fluxes of SS and P from beef pastures, dairy pastures and unsewered residential areas were similar to those from rainforest, while fluxes from areas of sugar cane and bananas were 3-4 times higher. Specific fluxes of N from areas with an annual precipitation of 3545 mm ranged from 8.9 ± 6.5 kg N ha-1 y-1 (rainforest) to 72 ± 50 kg N ha-1 y-1 (unsewered residential). Aggregated across the entire catchment, disproportionately large fluxes of SS, total P and total N were derived from

  16. Wave Dissipation on Low- to Super-Energy Coral Reefs

    Science.gov (United States)

    Harris, D. L.

    2016-02-01

    Coral reefs are valuable, complex and bio-diverse ecosystems and are also known to be one of the most effective barriers to swell events in coastal environments. Previous research has found coral reefs to be remarkably efficient in removing most of the wave energy during the initial breaking and transformation on the reef flats. The rate of dissipation is so rapid that coral reefs have been referred to as rougher than any known coastal barrier. The dissipation of wave energy across reef flats is crucial in maintaining the relatively low-energy conditions in the back reef and lagoonal environments providing vital protection to adjacent beach or coastal regions from cyclone and storm events. A shift in the regulation of wave energy by reef flats could have catastrophic consequences ecologically, socially, and economically. This study examined the dissipation of wave energy during two swell events in Tahiti and Moorea, French Polyesia. Field sites were chosen in varying degrees of exposure and geomorphology from low-energy protected sites (Tiahura, Moorea) to super-energy sites (Teahupo'o, Tahiti). Waves were measured during two moderate to large swell events in cross reef transects using short-term high-resolution pressure transducers. Wave conditions were found to be similar in all back reef locations despite the very different wave exposure at each reef site. However, wave conditions on the reef flats were different and mirrored the variation in wave exposure with depth over the reef flat the primary regulator of reef flat wave height. These results indicate that coral reef flats evolve morphodynamically with the wave climate, which creates coral reef geomorphologies capable of dissipating wave energy that results in similar back reef wave conditions regardless of the offshore wave climate.

  17. Will Coral Islands maintain their growth over the next century? A deterministic model of sediment availability at Lady Elliot Island, Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Sarah Hamylton

    Full Text Available A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present, present and future (2010-2100 time periods. Reef platform sediment production is estimated at 569 m3 yr-1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate removal from the reef system. Key carbonate producers including hard coral, crustose coralline algae and Halimeda are mapped accurately (mean R2 = 0.81. Community net production estimates correspond closely to independent census-based estimates made in-situ (R2 = 0.86. Reef-scale outputs are compared with historic rates of production generated from (i radiocarbon evidence of island deposition initiation around 3200 years ago, and (ii island volume calculated from a high resolution island digital elevation model. Contemporary carbonate production rates appear to be remarkably similar to historical values of 573 m3 yr-1. Anticipated future seawater chemistry parameters associated with an RCP8.5 emissions scenario are employed to model rates of net community calcification for the period 2000-2100 on the basis of an inorganic aragonite precipitation law, under the assumption of constant benthic community character. Simulations indicate that carbonate production will decrease linearly to a level of 118 m3 yr-1 by 2100 and that by 2150 aragonite saturation levels may no longer support the positive budgetary status necessary to sustain island accretion. Novel aspects of this assessment include the development of rate law parameters to realistically represent the variable composition of coral reef benthic carbonate producers, incorporation of three dimensional rugosity of the entire reef platform and the coupling of model outputs with both historical radiocarbon dating evidence and forward hydrochemical projections to conduct an assessment of island evolution

  18. Will Coral Islands maintain their growth over the next century? A deterministic model of sediment availability at Lady Elliot Island, Great Barrier Reef.

    Science.gov (United States)

    Hamylton, Sarah

    2014-01-01

    A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present), present and future (2010-2100) time periods. Reef platform sediment production is estimated at 569 m3 yr-1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate removal from the reef system. Key carbonate producers including hard coral, crustose coralline algae and Halimeda are mapped accurately (mean R2 = 0.81). Community net production estimates correspond closely to independent census-based estimates made in-situ (R2 = 0.86). Reef-scale outputs are compared with historic rates of production generated from (i) radiocarbon evidence of island deposition initiation around 3200 years ago, and (ii) island volume calculated from a high resolution island digital elevation model. Contemporary carbonate production rates appear to be remarkably similar to historical values of 573 m3 yr-1. Anticipated future seawater chemistry parameters associated with an RCP8.5 emissions scenario are employed to model rates of net community calcification for the period 2000-2100 on the basis of an inorganic aragonite precipitation law, under the assumption of constant benthic community character. Simulations indicate that carbonate production will decrease linearly to a level of 118 m3 yr-1 by 2100 and that by 2150 aragonite saturation levels may no longer support the positive budgetary status necessary to sustain island accretion. Novel aspects of this assessment include the development of rate law parameters to realistically represent the variable composition of coral reef benthic carbonate producers, incorporation of three dimensional rugosity of the entire reef platform and the coupling of model outputs with both historical radiocarbon dating evidence and forward hydrochemical projections to conduct an assessment of island evolution through time

  19. Temporal variation in macroinvertebrates associated with intertidal sponge Ircinia fusca (Carter 1880) from Ratnagiri, West coast, India.

    Digital Repository Service at National Institute of Oceanography (India)

    Sivadas, S.K.; Redij, A.G.S.; Sagare, P.; Thakur, N.L.; Ingole, B.S.

    : similarity profiles and biota-environment linkage, J. Exp. Mar. Biol. Ecol., 366 (2008) 56-69. 18 Villamizar, E., Laughlin, R.A., Fauna associated with the sponges Aplysina archeri and Aplysina etroit in a coral reef of the Archipiélago de Los Roques...

  20. Vaal Reefs

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Vaal Reefs Mine, the world's top gold producer with an output last quarter of 19,6 tons of gold, is to expand further with the building of an 120 000t/month run-of-mine mill at the new No 9 Shaft in the south area, linked with a carbon-in-pulp plant

  1. Giving the early fossil record of sponges a squeeze.

    Science.gov (United States)

    Antcliffe, Jonathan B; Callow, Richard H T; Brasier, Martin D

    2014-11-01

    Twenty candidate fossils with claim to be the oldest representative of the Phylum Porifera have been re-analysed. Three criteria are used to assess each candidate: (i) the diagnostic criteria needed to categorize sponges in the fossil record; (ii) the presence, or absence, of such diagnostic features in the putative poriferan fossils; and (iii) the age constraints for the candidate fossils. All three criteria are critical to the correct interpretation of any fossil and its placement within an evolutionary context. Our analysis shows that no Precambrian fossil candidate yet satisfies all three of these criteria to be a reliable sponge fossil. The oldest widely accepted candidate, Mongolian silica hexacts from c. 545 million years ago (Ma), are here shown to be cruciform arsenopyrite crystals. The oldest reliable sponge remains are siliceous spicules from the basal Cambrian (Protohertzina anabarica Zone) Soltanieh Formation, Iran, which are described and analysed here in detail for the first time. Extensive archaeocyathan sponge reefs emerge and radiate as late as the middle of the Fortunian Stage of the Cambrian and demonstrate a gradual assembly of their skeletal structure through this time coincident with the evolution of other metazoan groups. Since the Porifera are basal in the Metazoa, their presence within the late Proterozoic has been widely anticipated. Molecular clock calibration for the earliest Porifera and Metazoa should now be based on the Iranian hexactinellid material dated to c. 535 Ma. The earliest convincing fossil sponge remains appeared at around the time of the Precambrian-Cambrian boundary, associated with the great radiation events of that interval. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

  2. Process for purifying zirconium sponge

    International Nuclear Information System (INIS)

    Abodishish, H.A.M.; Kimball, L.S.

    1992-01-01

    This patent describes a Kroll reduction process wherein a zirconium sponge contaminated with unreacted magnesium and by-product magnesium chloride is produced as a regulus, a process for purifying the zirconium sponge. It comprises: distilling magnesium and magnesium chloride from: a regulus containing a zirconium sponge and magnesium and magnesium chloride at a temperature above about 800 degrees C and at an absolute pressure less than about 10 mmHg in a distillation vessel to purify the zirconium sponge; condensing the magnesium and the magnesium chloride distilled from the zirconium sponge in a condenser; and then backfilling the vessel containing the zirconium sponge and the condenser containing the magnesium and the magnesium chloride with a gas; recirculating the gas between the vessel and the condenser to cool the zirconium sponge from above about 800 degrees C to below about 300 degrees C; and cooling the recirculating gas in the condenser containing the condensed magnesium and the condensed magnesium chloride as the gas cools the zirconium sponge to below about 300 degrees C

  3. Temporal changes in the diazotrophic bacterial communities associated with Caribbean sponges Ircinia stroblina and Mycale laxissima

    Directory of Open Access Journals (Sweden)

    Fan eZhang

    2014-10-01

    Full Text Available Sponges that harbor microalgal or cyanobacterial symbionts may benefit from photosynthetically derived carbohydrates, which are rich in carbon but devoid of nitrogen, and may therefore encounter nitrogen limitation. Diazotrophic communities associated with two Caribbean sponges, Ircinia strobilina and Mycale laxissima were studied in a time series during which three individuals of each sponge were collected in four time points (5:00 AM, 12:00 noon, 5:00 PM, 10:00 PM. nifH genes were successfully amplified from the corresponding gDNA and cDNA pools and sequenced by high throughput 454 amplicon sequencing. In both sponges, over half the nifH transcripts were classified as from cyanobacteria and the remainder from heterotrophic bacteria. We found various groups of bacteria actively expressing the nifH gene during the entire day-night cycle, an indication that the nitrogen fixation potential was fully exploited by different nitrogen fixing bacteria groups associated with their hosts. This study showed for the first time the dynamic changes in the activity of the diazotrophic bacterial communities in marine sponges. Our study expands understanding of the diazotrophic groups that contribute to the fixed nitrogen pool in the benthic community. Sponge bacterial community-associated diazotrophy may have an important impact on the nitrogen biogeochemical cycle in the coral reef ecosystem.

  4. Temporal changes in the diazotrophic bacterial communities associated with Caribbean sponges Ircinia stroblina and Mycale laxissima.

    Science.gov (United States)

    Zhang, Fan; Vicente, Jan; Hill, Russell T

    2014-01-01

    Sponges that harbor microalgal or, cyanobacterial symbionts may benefit from photosynthetically derived carbohydrates, which are rich in carbon but devoid of nitrogen, and may therefore encounter nitrogen limitation. Diazotrophic communities associated with two Caribbean sponges, Ircinia strobilina and Mycale laxissima were studied in a time series during which three individuals of each sponge were collected in four time points (5:00 AM, 12:00 noon, 5:00 PM, 10:00 PM). nifH genes were successfully amplified from the corresponding gDNA and cDNA pools and sequenced by high throughput 454 amplicon sequencing. In both sponges, over half the nifH transcripts were classified as from cyanobacteria and the remainder from heterotrophic bacteria. We found various groups of bacteria actively expressing the nifH gene during the entire day-night cycle, an indication that the nitrogen fixation potential was fully exploited by different nitrogen fixing bacteria groups associated with their hosts. This study showed for the first time the dynamic changes in the activity of the diazotrophic bacterial communities in marine sponges. Our study expands understanding of the diazotrophic groups that contribute to the fixed nitrogen pool in the benthic community. Sponge bacterial community-associated diazotrophy may have an important impact on the nitrogen biogeochemical cycle in the coral reef ecosystem.

  5. 21 CFR 886.4790 - Ophthalmic sponge.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic sponge. 886.4790 Section 886.4790 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4790 Ophthalmic sponge. (a) Identification. An ophthalmic sponge is a device that is an absorbant sponge, pad, or spear made of folded gauze, cotton...

  6. Coral zonation and diagenesis of an emergent Pleistocene patch reef, Belize, Central America

    Energy Technology Data Exchange (ETDEWEB)

    Lighty, R.G.; Russell, K.L.

    1985-01-01

    Transect mapping and petrologic studies reveal a new depositional model and limited diagenesis of a well-exposed Pleistocene reef outcrop at Ambergris Cay, northern Belize. This emergent shelf-edge reef forms a rocky wave-washed headland at the northern terminus of the present-day 250 km long flourishing Belize Barrier Reef. Previously, the Belize reef outcrop was thought to extend southward in the subsurface beneath the modern barrier reef as a Pleistocene equivalent. The authors study indicate that this outcrop is a large, coral patch reef and not part of a barrier reef trend. Sixteen transects 12.5 m apart described in continuous cm increments from fore reef to back reef identified: extensive deposits of broken Acropora cervicornis; small thickets of A. palmata with small, oriented branches; and muddy skeletal sediments with few corals or reef rubble. Thin section and SEM studies show three phases of early submarine cementation: syntaxial and rosette aragonite; Mg-calcite rim cement and peloids; and colloidal Mg-calcite geopetal fill. Subaerial exposure in semi-arid northern Belize caused only minor skeletal dissolution, some precipitation of vadose whisker calcite, and no meteoric phreatic diagenesis. Facies geometry, coral assemblages, lack of rubble deposits, coralline algal encrustations and Millepora framework, and recognition of common but discrete submarine cements, all indicate that this Pleistocene reef was an isolated, coral-fringed sediment buildup similar to may large patch reefs existing today in moderate-energy shelf environments behind the modern barrier reef in central and southern Belize.

  7. Sponge systematics facing new challenges.

    Science.gov (United States)

    Cárdenas, P; Pérez, T; Boury-Esnault, N

    2012-01-01

    Systematics is nowadays facing new challenges with the introduction of new concepts and new techniques. Compared to most other phyla, phylogenetic relationships among sponges are still largely unresolved. In the past 10 years, the classical taxonomy has been completely overturned and a review of the state of the art appears necessary. The field of taxonomy remains a prominent discipline of sponge research and studies related to sponge systematics were in greater number in the Eighth World Sponge Conference (Girona, Spain, September 2010) than in any previous world sponge conferences. To understand the state of this rapidly growing field, this chapter proposes to review studies, mainly from the past decade, in sponge taxonomy, nomenclature and phylogeny. In a first part, we analyse the reasons of the current success of this field. In a second part, we establish the current sponge systematics theoretical framework, with the use of (1) cladistics, (2) different codes of nomenclature (PhyloCode vs. Linnaean system) and (3) integrative taxonomy. Sponges are infamous for their lack of characters. However, by listing and discussing in a third part all characters available to taxonomists, we show how diverse characters are and that new ones are being used and tested, while old ones should be revisited. We then review the systematics of the four main classes of sponges (Hexactinellida, Calcispongiae, Homoscleromorpha and Demospongiae), each time focusing on current issues and case studies. We present a review of the taxonomic changes since the publication of the Systema Porifera (2002), and point to problems a sponge taxonomist is still faced with nowadays. To conclude, we make a series of proposals for the future of sponge systematics. In the light of recent studies, we establish a series of taxonomic changes that the sponge community may be ready to accept. We also propose a series of sponge new names and definitions following the PhyloCode. The issue of phantom species

  8. Upper Silurian reef mounds on a shallowing carbonate ramp, Devon Island, Arctic Canada

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, O A [Ottawa Univ., ON (Canada); Graf, G C [Chevron Canada Resources, Calgary, AB (Canada)

    1992-03-01

    Near Gascoyne Inlet, the topmost Douro and lowermost Barlow Inlet formations record overall upward shallowing from ramp to shallow shelf conditions. This transitional sequence contains bioherms of various sizes, from small isolated reef mounds 1-2 m across to larger, compound reef mounds over 50 m thick and 60 m across, as well as distictive inter- and pre-reef mound facies. The larger reef mounds show stages intermediate in character between those in sponge-dominated reef mounds of the Douro Formation and in larger stromatoporoid-crinoid dominated reefs in the Barlow Inlet Formation. Three principal reef mounds developed in turn. An initial partly lithified lime mudstone, containing scattered corals and apparently relict sponge-cryptomicrobial fabrics, developed on sheets of oncolitic storm debris in mainly low energy conditions between storm and fairweather wave bases. With gradual shallowing and progressively higher energy conditions above fairweather wave base, a middle facies of coral- and crinoid-rich mudstone developed. An abrupt deepening restored conditions of low energy, and the ensuing upper facies of the reef mounds is more varied, comprising sparsely fossiliferous and locally fenestral lime mudstones, patchy coral bafflestone and bindstone, coarse encrinites and substantially culminating stromatoporoid bindstone. 36 refs., 14 figs., 5 tabs.

  9. Accretion history and stratigraphy of mid-Holocene coral reefs from Southeast Florida, USA

    Science.gov (United States)

    Stathakopoulos, A.; Riegl, B. M.; Swart, P. K.

    2013-05-01

    The southeast Florida shelf is a well-studied coral reef region previously used in studies of late Quaternary sea-level, reef geomorphology, and paleoecology in the sub-tropical Atlantic. Situated on the shelf is the southeast Florida continental reef tract; a ~125 km long Holocene fringing/barrier coral reef complex, composed of three shore-parallel linear reefs ('outer', 'middle', and 'inner' reefs) of varying age. Since few detailed stratigraphic descriptions exist, drill cores were extracted to further understand the composition, character, and radiometric ages of reef material in order to reconstruct the accretion history. Sixteen reef cores from the shallow inner reef were collected along and across the reef axes and were combined with lidar bathymetric data for stratigraphic and geomorphologic analyses. Macroscopic and microscopic (petrographic thin sections) examinations of reef clasts were performed to identify coral and reef infauna species compositions, diagenetic facies, and taphonomic features for interpretation of former reef environments/zonation. The southeast Florida continental reef tract was characterized by dynamic reef terminations, backstepping, and re-initiation in response to post-glacial sea-level rise and flooding of topography suitable for reef initiation and growth. Results suggest that the outer reef accreted from ~10.6-8.0 ka cal BP, the middle reef from at least ~5.8-3.7 ka cal BP, and the inner reef from ~7.8-5.5 ka cal BP. The outer reef is the best-developed reef, followed by the inner reef, while the middle reef apparently has relatively little framework buildup. New data from this study and a lack of significant age overlaps confirm that reef backstepping from the outer to the inner reef occurred within a few hundred years after outer reef termination. This is consistent with temporal and spatial scales reported from backstepped reefs in St. Croix and Puerto Rico. The cause of the backstep is still unknown however some studies

  10. Asymmetric competition prevents the outbreak of an opportunistic species after coral reef degradation.

    Science.gov (United States)

    González-Rivero, Manuel; Bozec, Yves-Marie; Chollett, Iliana; Ferrari, Renata; Schönberg, Christine H L; Mumby, Peter J

    2016-05-01

    Disturbance releases space and allows the growth of opportunistic species, excluded by the old stands, with a potential to alter community dynamics. In coral reefs, abundances of fast-growing, and disturbance-tolerant sponges are expected to increase and dominate as space becomes available following acute coral mortality events. Yet, an increase in abundance of these opportunistic species has been reported in only a few studies, suggesting certain mechanisms may be acting to regulate sponge populations. To gain insights into mechanisms of population control, we simulated the dynamics of the common reef-excavating sponge Cliona tenuis in the Caribbean using an individual-based model. An orthogonal hypothesis testing approach was used, where four candidate mechanisms-algal competition, stock-recruitment limitation, whole and partial mortality-were incorporated sequentially into the model and the results were tested against independent field observations taken over a decade in Belize, Central America. We found that releasing space after coral mortality can promote C. tenuis outbreaks, but such outbreaks can be curtailed by macroalgal competition. The asymmetrical competitive superiority of macroalgae, given by their capacity to pre-empt space and outcompete with the sponge in a size-dependant fashion, supports their capacity to steal the opportunity from other opportunists. While multiple system stages can be expected in coral reefs following intense perturbation macroalgae may prevent the growth of other space-occupiers, such as bioeroding sponges, under low grazing pressure.

  11. Phylogenetic relationships among NE Atlantic Plocamionida Topsent (Porifera, Poecilosclerida): under-estimated diversity in reef ecosystems

    NARCIS (Netherlands)

    Reveillaud, J.; van Soest, R.; Derycke, S.; Picton, B.; Rigaux, A.; Vanreusel, A.

    2011-01-01

    Background: Small and cryptic sponges associated with cold-water coral reefs are particularly numerous and challenging to identify, but their ecological and biochemical importance is likely to compete with megabenthic specimens. Methodology/Principal Findings: Here we use a combination of the

  12. Unraveling the structure and composition of Varadero Reef, an improbable and imperiled coral reef in the Colombian Caribbean

    Directory of Open Access Journals (Sweden)

    Valeria Pizarro

    2017-12-01

    Full Text Available Coral reefs are commonly associated with oligotrophic, well-illuminated waters. In 2013, a healthy coral reef was discovered in one of the least expected places within the Colombian Caribbean: at the entrance of Cartagena Bay, a highly-polluted system that receives industrial and sewage waste, as well as high sediment and freshwater loads from an outlet of the Magdalena River (the longest and most populated river basin in Colombia. Here we provide the first characterization of Varadero Reef’s geomorphology and biological diversity. We also compare these characteristics with those of a nearby reference reef, Barú Reef, located in an area much less influenced by the described polluted system. Below the murky waters, we found high coral cover of 45.1% (±3.9; up to 80% in some sectors, high species diversity, including 42 species of scleractinian coral, 38 of sponge, three of lobster, and eight of sea urchin; a fish community composed of 61 species belonging to 24 families, and the typical zonation of a Caribbean fringing reef. All attributes found correspond to a reef that, according to current standards should be considered in “good condition”. Current plans to dredge part of Varadero threaten the survival of this reef. There is, therefore, an urgent need to describe the location and characteristics of Varadero as a first step towards gaining acknowledgement of its existence and garnering inherent legal and environmental protections.

  13. Marine sponges (Porifera: Demospongiae) from the Gulf of México, new records and redescription of Erylus trisphaerus (de Laubenfels, 1953).

    Science.gov (United States)

    Ugalde, Diana; Gómez, Patricia; Simões, Nuno

    2015-01-19

    Marine sponges usually constitute the most diverse group of the benthic community in coral reefs. Although they are reasonably well studied at the northern Gulf of Mexico (GMx), the southern GMx is poorly known and lacks records from many major reef systems that lie off the Mexican coast. The present taxonomic study is the first sponge account from Alacranes reef, the largest coral reef system in the GMx, and from the shallow reef banks of Sisal, both in the northwest Yucatan Peninsula. The 19 species herein described represent the first sponge fauna records from these reefs. Among these, seven species represent new record for GMx: Erylus formosus, Cliona flavifodina, Spirastrella aff. mollis, Strongylacidon bermuda, Topsentia bahamensis, Agelas tubulata and Chelonaplysilla aff. erecta. Twelve species are new records for the Southern GMx: Erylus trisphaerus, Cliona amplicavata, Chondrilla caribensis, Halichondria lutea, Hymeniacidon caerulea, Axinella corrugata, Dragmacidon reticulatum, Chalinula molitba, Amphimedon caribica, A. complanata, Hyatella cavernosa and Dysidea variabilis. Additionally, a redescription of Erylus trisphaerus is presented which had not been reviewed since its original description in 1953 off Western Florida, except that it was listed for north La Habana, Cuba. 

  14. Dynamics of internal waves on the Southeast Florida shelf: Implications for cross-shelf exchange and turbulent mixing on a barrier reef system

    Science.gov (United States)

    Davis, Kristen Alexis

    The dynamics of internal waves shoaling on the Southeast Florida shelf and the resulting stratified turbulence in the shelf bottom boundary layer are investigated using observational studies completed during the summers of 2003-2005. This work is driven by a desire to understand the effects of internal wave-driven flow and the shoreward transport of cool, nutrient-rich water masses on cross-shelf exchange, vertical mixing, and mass transfer to benthic reef organisms. Shelf sea internal wave fields are typically highly variable and dominated by wind and tidal forces. However, this is not necessarily true for outer shelf regions or very narrow shelves where remote physical processes originating over the slope or deep ocean may exert a strong influence on the internal wave climate. During the summers of 2003 and 2004 observational studies were conducted to examine the effects of a western boundary current (the Florida Current), tides, and wind on the mean currents and internal wave field on the outer Southeast Florida shelf. We present evidence that suggests that the Florida Current plays as large a role in the determination of the high frequency internal wave field as tidal forces. These observations and analyses show that it is necessary to include the forcing from the Florida Current meanders and instabilities in order to predict accurately the episodic nature of the internal wave field on the Southeast Florida shelf. Deep ocean and continental shelf processes intersect at the shelf edge and influence the exchange of water masses and their associated characteristics including heat, nutrients, sediment, and larvae across the shelf. Thus, the dynamics of cross-shelf circulation have important consequences for organisms living on the shelf. In the second phase of this work, we investigate physical mechanisms controlling the exchange of water masses during the summer season across the Southeast Florida shelf. A time series of cross-shelf transport from May to August

  15. Who’s there? – First morphological and DNA barcoding catalogue of the shallow Hawai’ian sponge fauna

    Science.gov (United States)

    Gates, Ruth D.

    2017-01-01

    The sponge fauna has been largely overlooked in the Archipelago of Hawai’i, notwithstanding the paramount role of this taxon in marine ecosystems. The lack of knowledge about Porifera populations inhabiting the Hawai’ian reefs limits the development of ecological studies aimed at understanding the functioning of these marine systems. Consequently, this project addresses this gap by describing the most representative sponge species in the shallow waters of the enigmatic bay of Kane’ohe Bay, in O’ahu Island. A total of 30 species (28 demosponges and two calcareous sponges) living associated to the reef structures are here reported. Six of these species are new records to the Hawai’ian Porifera catalogue and are suspected to be recent introductions to these islands. Morphological descriptions of the voucher specimens are provided, along with sequencing data of two partitions involving the mitochondrial cytochrome oxidase subunit 1 (COI) marker and a fragment covering partial (18S and 28S) and full (ITS-1, 5.8S and ITS-2) nuclear ribosomal genes. Species delimitations based on genetic distances were calculated to valitate how taxonomic assignments from DNA barcoding aligned with morphological identifications. Of the 60 sequences submitted to GenBank ~88% are the first sequencing records for the corresponding species and genetic marker. This work compiles the first catalogue combining morphological characters with DNA barcoding of Hawai’ian sponges, and contributes to the repository of public databases through the Sponge Barcoding Project initiative. PMID:29267311

  16. Biodiversity, molecular ecology and phylogeography of marine sponges: patterns, implications and outlooks.

    Science.gov (United States)

    Wörheide, Gert; Solé-Cava, Antonio M; Hooper, John N A

    2005-04-01

    Marine sponges are an ecologically important and highly diverse component of marine benthic communities, found in all the world's oceans, at all depths. Although their commercial potential and evolutionary importance is increasingly recognized, many pivotal aspects of their basic biology remain enigmatic. Knowledge of historical biogeographic affinities and biodiversity patterns is rudimentary, and there are still few data about genetic variation among sponge populations and spatial patterns of this variation. Biodiversity analyses of tropical Australasian sponges revealed spatial trends not universally reflected in the distributions of other marine phyla within the Indo-West Pacific region. At smaller spatial scales sponges frequently form heterogeneous, spatially patchy assemblages, with some empirical evidence suggesting that environmental variables such as light and/or turbidity strongly contribute to local distributions. There are no apparent latitudinal diversity gradients at larger spatial scales but stochastic processes, such as changing current patterns, the presence or absence of major carbonate platforms and historical biogeography, may determine modern day distributions. Studies on Caribbean oceanic reefs have revealed similar patterns, only weakly correlated with environmental factors. However, several questions remain where molecular approaches promise great potential, e.g., concerning connectivity and biogeographic relationships. Studies to date have helped to reveal that sponge populations are genetically highly structured and that historical processes might play an important role in determining such structure. Increasingly sophisticated molecular tools are now being applied, with results contributing significantly to a better understanding of poriferan microevolutionary processes and molecular ecology.

  17. 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.

  18. Natural diet of coral-excavating sponges consists mainly of dissolved organic carbon (DOC.

    Directory of Open Access Journals (Sweden)

    Benjamin Mueller

    Full Text Available Coral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. We therefore investigated the uptake of organic matter by the two coral-excavating sponges Siphonodictyon sp. and Cliona delitrix and tested whether they are capable of consuming dissolved organic carbon (DOC as part of their diet. A device for simultaneous sampling of water inhaled and exhaled by the sponges was used to directly measure the removal of DOC and bacteria in situ. During a single passage through their filtration system 14% and 13% respectively of the total organic carbon (TOC in the inhaled water was removed by the sponges. 82% (Siphonodictyon sp.; mean ± SD; 13 ± 17 μmol L(-1 and 76% (C. delitrix; 10 ± 12 μmol L(-1 of the carbon removed was taken up in form of DOC, whereas the remainder was taken up in the form of particulate organic carbon (POC; bacteria and phytoplankton despite high bacteria retention efficiency (72 ± 15% and 87 ± 10%. Siphonodictyon sp. and C. delitrix removed DOC at a rate of 461 ± 773 and 354 ± 562 μmol C h(-1 respectively. Bacteria removal was 1.8 ± 0.9 × 10(10 and 1.7 ± 0.6 × 10(10 cells h(-1, which equals a carbon uptake of 46.0 ± 21.2 and 42.5 ± 14.0 μmol C h(-1 respectively. Therefore, DOC represents 83 and 81% of the TOC taken up by Siphonodictyon sp. and C. delitrix per hour. These findings suggest that similar to various reef sponges coral-excavating sponges also mainly rely on DOC to meet their carbon demand. We hypothesize that excavating sponges may also benefit from an increasing production of more labile algal-derived DOC (as compared to coral-derived DOC on reefs as a result of the ongoing coral-algal phase shift.

  19. Natural diet of coral-excavating sponges consists mainly of dissolved organic carbon (DOC).

    Science.gov (United States)

    Mueller, Benjamin; de Goeij, Jasper M; Vermeij, Mark J A; Mulders, Yannick; van der Ent, Esther; Ribes, Marta; van Duyl, Fleur C

    2014-01-01

    Coral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. We therefore investigated the uptake of organic matter by the two coral-excavating sponges Siphonodictyon sp. and Cliona delitrix and tested whether they are capable of consuming dissolved organic carbon (DOC) as part of their diet. A device for simultaneous sampling of water inhaled and exhaled by the sponges was used to directly measure the removal of DOC and bacteria in situ. During a single passage through their filtration system 14% and 13% respectively of the total organic carbon (TOC) in the inhaled water was removed by the sponges. 82% (Siphonodictyon sp.; mean ± SD; 13 ± 17 μmol L(-1)) and 76% (C. delitrix; 10 ± 12 μmol L(-1)) of the carbon removed was taken up in form of DOC, whereas the remainder was taken up in the form of particulate organic carbon (POC; bacteria and phytoplankton) despite high bacteria retention efficiency (72 ± 15% and 87 ± 10%). Siphonodictyon sp. and C. delitrix removed DOC at a rate of 461 ± 773 and 354 ± 562 μmol C h(-1) respectively. Bacteria removal was 1.8 ± 0.9 × 10(10) and 1.7 ± 0.6 × 10(10) cells h(-1), which equals a carbon uptake of 46.0 ± 21.2 and 42.5 ± 14.0 μmol C h(-1) respectively. Therefore, DOC represents 83 and 81% of the TOC taken up by Siphonodictyon sp. and C. delitrix per hour. These findings suggest that similar to various reef sponges coral-excavating sponges also mainly rely on DOC to meet their carbon demand. We hypothesize that excavating sponges may also benefit from an increasing production of more labile algal-derived DOC (as compared to coral-derived DOC) on reefs as a result of the ongoing coral-algal phase shift.

  20. DEMONSTRATION BULLETIN: FORAGER™ SPONGE TECHNOLOGY - DYNAPHORE, INC.

    Science.gov (United States)

    The Forager™ Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that has selective affinity for dissolved heavy metals in both cationic and anionic states. The Forager™ Sponge technology can be utilized to remove and concentrate heavy me...

  1. Status and perspective of sponge chemosystematics.

    NARCIS (Netherlands)

    Erpenbeck, D.J.G.; van Soest, R.W.M.

    2007-01-01

    In addition to their pharmaceutical applications, sponges are an important source of compounds that are used to elucidate classification patterns and phylogenetic relationships. Here we present a review and outlook on chemosystematics in sponges in seven sections: Secondary metabolites in sponges;

  2. Sponges from Clipperton Island, East Pacific

    NARCIS (Netherlands)

    van Soest, R.W.M.; Kaiser, K.L.; van Syoc, R.

    2011-01-01

    Twenty sponge species (totalling 190 individuals) were collected during the 1938, 1994 and 2004/5 expeditions to the remote island of Clipperton in the East Pacific Ocean. Seven species are widespread Indo-Pacific sponges; nine species comprise sponges new to science; four species were represented

  3. Antimicrobial activities of secondary metabolites and phylogenetic study of sponge endosymbiotic bacteria, Bacillus sp. at Agatti Island, Lakshadweep Archipelago

    Directory of Open Access Journals (Sweden)

    Gopi Mohan

    2016-09-01

    Full Text Available Twenty-one species of sponges were recorded under the class of Demospongiae and Calcareous sponges of which 19 species were new to Agatti reef. A total of 113 Sponge endosymbiotic bacterial strains were isolated from twenty-one species of sponges and screened for antimicrobial activity. Five bacterial strains of sponge endosymbiotic bacteria (SEB namely SEB32, SEB33, SEB36, SEB43 and SEB51 showed antimicrobial activity against virulent marine fish pathogens such as Vibrio alginolyticus, Vibrio vulnificus, Vibrio parahaemolyticus, Aeromonas salmonicida, Flavobacterium sp., Edwardsiella sp., Proteus mirabilis and Citrobacter brackii. The secondary metabolites produced by SEB32 from sponge Dysidea fragilis (Montagu, 1818 [48] was selected with broad range of antibacterial activity and subjected for production, characterization by series of chromatography techniques and spectroscopic methods. Based on the results of FT-IR and mass spectrometry, the active molecule was tentatively predicted as “Pyrrol” and the structure is Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro- with molecular formula of C7H10N2O2. The LC50 of active molecule was 31 μg/ml and molecular weight of the metabolites was 154. The potential strain SEB32 was identified by gene sequence (GenBank Accession number JX985748 and identified as Bacillus sp. from GenBank database.

  4. 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...

  5. NMFS Reef Survey Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Reef Environmental Survey Project (REEF) mission to educate and enlist divers in the conservation of marine habitats is accomplished primarily through its Fish...

  6. Reef odor: a wake up call for navigation in reef fish larvae.

    Directory of Open Access Journals (Sweden)

    Claire B Paris

    Full Text Available The behavior of reef fish larvae, equipped with a complex toolbox of sensory apparatus, has become a central issue in understanding their transport in the ocean. In this study pelagic reef fish larvae were monitored using an unmanned open-ocean tracking device, the drifting in-situ chamber (DISC, deployed sequentially in oceanic waters and in reef-born odor plumes propagating offshore with the ebb flow. A total of 83 larvae of two taxonomic groups of the families Pomacentridae and Apogonidae were observed in the two water masses around One Tree Island, southern Great Barrier Reef. The study provides the first in-situ evidence that pelagic reef fish larvae discriminate reef odor and respond by changing their swimming speed and direction. It concludes that reef fish larvae smell the presence of coral reefs from several kilometers offshore and this odor is a primary component of their navigational system and activates other directional sensory cues. The two families expressed differences in their response that could be adapted to maintain a position close to the reef. In particular, damselfish larvae embedded in the odor plume detected the location of the reef crest and swam westward and parallel to shore on both sides of the island. This study underlines the critical importance of in situ Lagrangian observations to provide unique information on larval fish behavioral decisions. From an ecological perspective the central role of olfactory signals in marine population connectivity raises concerns about the effects of pollution and acidification of oceans, which can alter chemical cues and olfactory responses.

  7. Coral reefs and the World Bank.

    Science.gov (United States)

    Hatziolos, M

    1997-01-01

    The World Bank¿s involvement in coral reef conservation is part of a larger effort to promote the sound management of coastal and marine resources. This involves three major thrusts: partnerships, investments, networks and knowledge. As an initial partner and early supporter of the International Coral Reef Initiative (ICRI), the Bank serves as the executive planning committee of ICRI. In partnership with the World Conservation Union and the Great Barrier Reef Marine Park Authority, the Bank promotes the efforts towards the establishment and maintenance of a globally representative system of marine protected areas. In addition, the Bank invested over $120 million in coral reef rehabilitation and protection programs in several countries. Furthermore, the Bank developed a ¿Knowledge Bank¿ that would market ideas and knowledge to its clients along with investment projects. This aimed to put the best global knowledge on environmentally sustainable development in the hands of its staff and clients. During the celebration of 1997, as the International Year of the Reef, the Bank planned to cosponsor an associated event that would highlight the significance of coral reefs and encourage immediate action to halt their degradation to conserve this unique ecosystem.

  8. Community structure and ecological function of deep-water sponge grounds in the Traenadypet MPA—Northern Norwegian continental shelf

    Science.gov (United States)

    Kutti, Tina; Bannister, Raymond John; Fosså, Jan Helge

    2013-10-01

    Sponges within the 300 km2 Trænadypet coral MPA (Marine Protected Area) were mapped using photographic techniques. Three types of sponge communities were identified. The eastern side of the central circular depression was dominated by fan-shaped Phakellia ventilabrum sponges and further characterized by Mycale lingua and Oceanapia spp. sponges. Phakellia ventilabrum abundance (0.34 ind m-2) was positively correlated with the number of drop stones found. The western side of the depression was dominated by Geodia barretti, G. macandrewii and G. atlantica with an estimated average abundance of 0.40 ind m-2 and a biomass of 2.4 kg WW m-2. A third type of sponge community was found on both sides of the depression (in between the small scattered cold-water coral reefs constituting the MPA), which was characterized by Mycale lingua (0.20 ind m-2) and Oceanapia spp. (0.10 ind m-2), and which supported a high average Geodiidea biomass (1.6 kg WW m-2). The two last communities were both of the boreal ostur type and seemed to form continuous belts along the 2 km transects surveyed only interrupted by a few 15-30 m long empty patches. Within the MPA the average overall biomass of Geodiidea sponges was 1.8 kg WW m-2 and the overall sponge abundance was 1 ind m-2. Water pumping rates and respiration of Geodia barretti were measured, equating to 3000 l kg-1 DW day-1 and 1.5 μmol O2 g-1 DW h-1, respectively. Up-scaling this to the MPA as a whole suggests that the population of G. barretti alone could filter approximately 250 million m3 of water and consume 60 t of carbon daily. This demonstrates the important ecological function of sponges as nutrient vectors and points out the MPA as an ecologically significant area that should be carefully managed and monitored.

  9. Sponge Hybridomas: Applications and Implications

    NARCIS (Netherlands)

    Pomponi, S.A.; Jevitt, A.; Patel, J.; Diaz, M.C.

    2013-01-01

    Many sponge-derived natural products with applications to human health have been discovered over the past three decades. In vitro production has been proposed as one biological alternative to ensure adequate supply of marine natural products for preclinical and clinical development of drugs.

  10. Chemical ecology of marine sponges

    Digital Repository Service at National Institute of Oceanography (India)

    Thakur, N.L.; Singh, A.

    . University of California Press, Berkeley/Los Angeles, 268 pp Bewley CA, He H, Williams DH, Faulkner DJ (1996) Aciculitins AC: cytotoxic and antifungal cyclic pep- tides from the lithistid sponge Aciculites orientalis. J Am Chem Soc 118(18):4314–4321 48 N...

  11. Barbabos Deep-Water Sponges

    NARCIS (Netherlands)

    Soest, van R.W.M.; Stentoft, N.

    1988-01-01

    Deep-water sponges dredged up in two locations off the west coast of Barbados are systematically described. A total of 69 species is recorded, among which 16 are new to science, viz. Pachymatisma geodiformis, Asteropus syringiferus, Cinachyra arenosa, Theonella atlantica. Corallistes paratypus,

  12. Morphological plasticity in the tropical sponge Anthosigmella varians: responses to predators and wave energy.

    Science.gov (United States)

    Hill, Malcolm S; Hill, April L

    2002-02-01

    The goal of the research presented here was to examine phenotypic plasticity exhibited by three morphotypes of the common Caribbean sponge Anthosigmella varians (Duchassaing & Michelotti). We were interested in examining the biotic (and, to a lesser extent, abiotic) factors responsible for branch production in this species. We also tested the hypothesis that the skeleton may serve an antipredator function in this sponge, focusing on vertebrate fish predators (i.e., angelfish) in this work. In transplant and caging experiments, unprotected forma varians replicates were immediately consumed by angelfish, while caged replicates persisted on the reef for several months. These findings support the hypothesis that predators (and not wave energy) restrict forma varians to lagoonal habitats. Branch production was not observed in A. varians forma incrustans when sponges were protected from predators or placed in predator-free, low-wave-energy environments. It is not clear from our work whether forma incrustans is capable of producing branches (i.e., whether branch production is a plastic trait in this morph). Additional field experiments demonstrated that A. varians forma varians increased spicule concentrations, compared to uninjured sponges, in response to artificial predation events, and A. varians forma rigida reduced spicule concentrations, compared to uncaged controls, when protected from predators. These findings indicate that spicule concentration is a plastic morphological trait that can be induced by damage, and that A. varians may be able to reduce spicule concentrations when environmental conditions change (e.g., in the absence of predators). The potential significance of inducible defenses and structural anti-predator defenses in sponges is discussed in relation to recent work on sponge chemical defenses.

  13. Functionally diverse reef-fish communities ameliorate coral disease.

    Science.gov (United States)

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

    2009-10-06

    Coral reefs, the most diverse of marine ecosystems, currently experience unprecedented levels of degradation. Diseases are now recognized as a major cause of mortality in reef-forming corals and are complicit in phase shifts of reef ecosystems to algal-dominated states worldwide. Even so, factors contributing to disease occurrence, spread, and impact remain poorly understood. Ecosystem resilience has been linked to the conservation of functional diversity, whereas overfishing reduces functional diversity through cascading, top-down effects. Hence, we tested the hypothesis that reefs with trophically diverse reef fish communities have less coral disease than overfished reefs. We surveyed reefs across the central Philippines, including well-managed marine protected areas (MPAs), and found that disease prevalence was significantly negatively correlated with fish taxonomic diversity. Further, MPAs had significantly higher fish diversity and less disease than unprotected areas. We subsequently investigated potential links between coral disease and the trophic components of fish diversity, finding that only the density of coral-feeding chaetodontid butterflyfishes, seldom targeted by fishers, was positively associated with disease prevalence. These previously uncharacterized results are supported by a second large-scale dataset from the Great Barrier Reef. We hypothesize that members of the charismatic reef-fish family Chaetodontidae are major vectors of coral disease by virtue of their trophic specialization on hard corals and their ecological release in overfished areas, particularly outside MPAs.

  14. Using virtual reality to estimate aesthetic values of coral reefs

    Science.gov (United States)

    Clifford, Sam; Caley, M. Julian; Pearse, Alan R.; Brown, Ross; James, Allan; Christensen, Bryce; Bednarz, Tomasz; Anthony, Ken; González-Rivero, Manuel; Mengersen, Kerrie; Peterson, Erin E.

    2018-01-01

    Aesthetic value, or beauty, is important to the relationship between humans and natural environments and is, therefore, a fundamental socio-economic attribute of conservation alongside other ecosystem services. However, beauty is difficult to quantify and is not estimated well using traditional approaches to monitoring coral-reef aesthetics. To improve the estimation of ecosystem aesthetic values, we developed and implemented a novel framework used to quantify features of coral-reef aesthetics based on people's perceptions of beauty. Three observer groups with different experience to reef environments (Marine Scientist, Experienced Diver and Citizen) were virtually immersed in Australian's Great Barrier Reef (GBR) using 360° images. Perceptions of beauty and observations were used to assess the importance of eight potential attributes of reef-aesthetic value. Among these, heterogeneity, defined by structural complexity and colour diversity, was positively associated with coral-reef-aesthetic values. There were no group-level differences in the way the observer groups perceived reef aesthetics suggesting that past experiences with coral reefs do not necessarily influence the perception of beauty by the observer. The framework developed here provides a generic tool to help identify indicators of aesthetic value applicable to a wide variety of natural systems. The ability to estimate aesthetic values robustly adds an important dimension to the holistic conservation of the GBR, coral reefs worldwide and other natural ecosystems. PMID:29765676

  15. 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.

  16. Wnt signaling and polarity in freshwater sponges.

    Science.gov (United States)

    Windsor Reid, Pamela J; Matveev, Eugueni; McClymont, Alexandra; Posfai, Dora; Hill, April L; Leys, Sally P

    2018-02-02

    The Wnt signaling pathway is uniquely metazoan and used in many processes during development, including the formation of polarity and body axes. In sponges, one of the earliest diverging animal groups, Wnt pathway genes have diverse expression patterns in different groups including along the anterior-posterior axis of two sponge larvae, and in the osculum and ostia of others. We studied the function of Wnt signaling and body polarity formation through expression, knockdown, and larval manipulation in several freshwater sponge species. Sponge Wnts fall into sponge-specific and sponge-class specific subfamilies of Wnt proteins. Notably Wnt genes were not found in transcriptomes of the glass sponge Aphrocallistes vastus. Wnt and its signaling genes were expressed in archaeocytes of the mesohyl throughout developing freshwater sponges. Osculum formation was enhanced by GSK3 knockdown, and Wnt antagonists inhibited both osculum development and regeneration. Using dye tracking we found that the posterior poles of freshwater sponge larvae give rise to tissue that will form the osculum following metamorphosis. Together the data indicate that while components of canonical Wnt signaling may be used in development and maintenance of osculum tissue, it is likely that Wnt signaling itself occurs between individual cells rather than whole tissues or structures in freshwater sponges.

  17. Modeling Reef Island Morphodynamics in Profile and Plan View

    Science.gov (United States)

    Ashton, A. D.; Ortiz, A. C.; Lorenzo-Trueba, J.

    2016-12-01

    Reef islands are carbonate detrital landforms perched atop shallow reef flats of atolls and barrier reef systems. Often comprising the only subaerial, inhabitable land of many island chains and island nations, these low-lying, geomorphically active landforms face considerable hazards from climate change. While there hazards include wave overtopping and groundwater salinization, sea-level rise and wave climate change will affect sediment transport and shoreline dynamics, including the possibility for wholesale reorganization of the islands themselves. Here we present a simplified morphodynamic model that can spatially quantify the potential impacts of climate change on reef islands. Using parameterizations of sediment transport pathways and feedbacks from previously presented XBeach modeling results, we investigate how sea-level rise, change in storminess, and different carbonate production rates can affect the profile evolution of reef islands, including feedbacks with the shallow reef flat that bounds the islands offshore (and lagoonward). Model results demonstrate that during rising sea levels, the reef flat can serve as a sediment trap, starving reef islands of detrital sediment that could otherwise fortify the shore against sea-level-rise-driven erosion. On the other hand, if reef flats are currently shallow (likely due to geologic inheritance or biologic cementation processes) such that sea-level rise does not result in sediment accumulation on the flat, reef island shorelines may be more resilient to rising seas. We extend the model in plan view to examine how long-term (decadal) changes in wave approach direction could affect reef island shoreline orientation. We compare model results to historical and geologic change for different case studies on the Marshall Islands. This simplified modeling approach, focusing on boundary dynamics and mass fluxes, provides a quantitative tool to predict the response of reef island environments to climate change.

  18. Steroids from marine sponges Suberites vestigium and Chrotella australiensis

    Digital Repository Service at National Institute of Oceanography (India)

    Mishra, P.D; Wahidullah, S.; De; Kamat, S.Y.

    The sponges Suberites vestigium and Chrotella australiensis have been examined for steriods. Both the sponges contain C sub(27-29) mono and diunsaturated sterols, in addition sponge C. australiensis contains cholest-4-ene-3-one and 24-ethyl cholest...

  19. Connectivity in a Red Sea Sponge across an Environmental Gradient

    KAUST Repository

    Giles, Emily C.

    2014-08-01

    While geographic distance is a variable often used to explain population genetic differentiation, dynamic processes leading to stochastic population structure are more likely driving factors. The following thesis presents the population structure of a common reef sponge, Stylissa carteri, and yields hypotheses on the influence of environmental heterogeneity as a predictor of the observed population structure. This project represents the largest population genetics study thus conducted in the Red Sea and also includes the first population genetics data gathered for sites off the coast of Sudan and Soccotra. The study herein presented includes both a large scale (36 reef sites covering over 1000km of coastline) and small-scale (16 transects of 50m each) analysis of gene flow in a benthic dwelling organism. The variable effect of geography and environmental conditions on S. carteri population structure is assessed using a seascape genetics approach. Environmental factors from a nine-year dataset accessed from the NASA Giovanni website including chlorophyll a, sea surface temperature, dissolved and particulate organic matter for both the annual and winter temporal scale were considered.

  20. Who Produces Ianthelline? The Arctic Sponge Stryphnus fortis or its Sponge Epibiont Hexadella dedritifera: a Probable Case of Sponge-Sponge Contamination.

    Science.gov (United States)

    Cárdenas, Paco

    2016-04-01

    The bromotyrosine derivative ianthelline was isolated recently from the Atlantic boreo-arctic deep-sea sponge Stryphnus fortis, and shown to have clear antitumor and antifouling effects. However, chemosystematics, field observations, and targeted metabolic analyses (using UPLC-MS) suggest that ianthelline is not produced by S. fortis but by Hexadella dedritifera, a sponge that commonly grows on S. fortis. This case highlights the importance of combining taxonomic and ecological knowledge to the field of sponge natural products research.

  1. Sponges from Clipperton Island, East Pacific

    OpenAIRE

    van Soest, R.W.M.; Kaiser, K.L.; van Syoc, R.

    2011-01-01

    Twenty sponge species (totalling 190 individuals) were collected during the 1938, 1994 and 2004/5 expeditions to the remote island of Clipperton in the East Pacific Ocean. Seven species are widespread Indo-Pacific sponges; nine species comprise sponges new to science; four species were represented only by small thin patches insufficient for proper characterization and could be only determined to genus. The new species may not be necessarily endemic to the island, as several show similarities ...

  2. Bioactive alkaloids from marine sponges

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, K.S.; Majik, M.S.

    lines while kuanoniamine C was less potent but showed high selectivity toward the estrogen dependent breast cancer cell line (Kijjoa et. al., 2007). Recently, Davis’s and coworkers, reported two new cytotoxici- ty peridoacridine alkaloids viz... 10 sponge, Trachycladus laevispirulifer. Excitingly, it displayed promising selective cytotoxicity against a panel of human cancer cell lines. 12.3.1. BISINDOLE ALKALOIDS Bis-indole alkaloids, consisting of two indole moieties...

  3. Invasive lionfish preying on critically endangered reef fish

    Science.gov (United States)

    Rocha, Luiz A.; Rocha, Claudia R.; Baldwin, Carole C.; Weigt, Lee A.; McField, Melanie

    2015-09-01

    Caribbean coral reef ecosystems are at the forefront of a global decline and are now facing a new threat: elimination of vulnerable species by the invasive lionfish ( Pterois spp.). In addition to being threatened by habitat destruction and pollution, the critically endangered social wrasse ( Halichoeres socialis), endemic to Belize's inner barrier reef, has a combination of biological traits (small size, schooling, and hovering behavior) that makes it a target for the invasive lionfish. Based on stomach content analyses, this small fish comprises almost half of the lionfish diet at the inner barrier reef in Belize. The combination of lionfish predation, limited range, and ongoing habitat destruction makes the social wrasse the most threatened coral reef fish in the world. Other species with small range and similar traits occur elsewhere in the Caribbean and face similar risks.

  4. Metabolite variability in Caribbean sponges of the genus Aplysina

    Directory of Open Access Journals (Sweden)

    Monica Puyana

    Full Text Available Abstract Sponges of the genus Aplysina are among the most common benthic animals on reefs of the Caribbean, and display a wide diversity of morphologies and colors. Tissues of these sponges lack mineralized skeletal elements, but contain a dense spongin skeleton and an elaborate series of tyrosine-derived brominated alkaloid metabolites that function as chemical defenses against predatory fishes, but do not deter some molluscs. Among the earliest marine natural products to be isolated and identified, these metabolites remain the subject of intense interest for commercial applications because of their activities in various bioassays. In this study, crude organic extracts from 253 sponges from ten morphotypes among the species Aplysina archeri,Aplysina bathyphila,Aplysina cauliformis,Aplysina fistularis,Aplysina fulva,A. insularis, and Aplysina lacunosa were analyzed by liquid chromatography–mass spectrometry (LC–MS to characterize the pattern of intra- and interspecific variabilities of the twelve major secondary metabolites present therein. Patterns across Aplysina species ranged from the presence of mostly a single compound, fistularin-3, in A. cauliformis, to a mixture of metabolites present in the other species. These patterns did not support the biotransformation hypothesis for conversion of large molecular weight molecules to smaller ones for the purpose of enhanced defense. Discriminant analyses of the metabolite data revealed strong taxonomic patterns that support a close relationship between A. fistularis,A. fulva and A. insularis, while two morphotypes of A. cauliformis (lilac creeping vs. brown erect were very distinct. Two morphotypes of A. lacunosa, one with hard tissue consistency, the other soft and thought to belong to a separate genus (Suberea, had very similar chemical profiles. Of the twelve metabolites found among samples, variation in fistularin-3, dideoxyfistularin-3 and hydroxyaerothionin provided the most predictive

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

    Directory of Open Access Journals (Sweden)

    Christopher H. R. Goatley

    2016-03-01

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

  6. Biodiversity, zoogeography and affinity of Orissa sponges

    Digital Repository Service at National Institute of Oceanography (India)

    Thomas, P.A.; Sree, A.; Bapuji, M.; Rao, K.M.; Murthy, K.S.R.

    . Along with coral reefs, the ridge reefs gained importance for the study of different coral populations. With the advent of SCUBA and submersibles scientists have been able to initiate careful studies of subtidal / benthic faunal communities. With the use...

  7. Elevated seawater temperature disrupts the microbiome of an ecologically important bioeroding sponge.

    Science.gov (United States)

    Ramsby, Blake D; Hoogenboom, Mia O; Whalan, Steve; Webster, Nicole S

    2018-04-01

    Bioeroding sponges break down calcium carbonate substratum, including coral skeleton, and their capacity for reef erosion is expected to increase in warmer and more acidic oceans. However, elevated temperature can disrupt the functionally important microbial symbionts of some sponge species, often with adverse consequences for host health. Here, we provide the first detailed description of the microbial community of the bioeroding sponge Cliona orientalis and assess how the community responds to seawater temperatures incrementally increasing from 23°C to 32°C. The microbiome, identified using 16S rRNA gene sequencing, was dominated by Alphaproteobacteria, including a single operational taxonomic unit (OTU; Rhodothalassium sp.) that represented 21% of all sequences. The "core" microbial community (taxa present in >80% of samples) included putative nitrogen fixers and ammonia oxidizers, suggesting that symbiotic nitrogen metabolism may be a key function of the C. orientalis holobiont. The C. orientalis microbiome was generally stable at temperatures up to 27°C; however, a community shift occurred at 29°C, including changes in the relative abundance and turnover of microbial OTUs. Notably, this microbial shift occurred at a lower temperature than the 32°C threshold that induced sponge bleaching, indicating that changes in the microbiome may play a role in the destabilization of the C. orientalis holobiont. C. orientalis failed to regain Symbiodinium or restore its baseline microbial community following bleaching, suggesting that the sponge has limited ability to recover from extreme thermal exposure, at least under aquarium conditions. © 2018 John Wiley & Sons Ltd.

  8. Renal acidification defects in medullary sponge kidney

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1988-01-01

    Thirteen patients with medullary sponge kidney underwent a short ammonium chloride loading test to investigate their renal acidification capacity. All but 1 presented with a history of recurrent renal calculi and showed bilateral widespread renal medullary calcification on X-ray examination. Nine...... of renal calculi in medullary sponge kidney, have considerable therapeutic implications....

  9. Metal sponge for cryosorption pumping applications

    International Nuclear Information System (INIS)

    Myneni, G.R.; Kneisel, P.

    1995-01-01

    A system has been developed for adsorbing gases at high vacuum in a closed area. The system utilizes large surface clean anodized metal surfaces at low temperatures to adsorb the gases. The large surface clean anodized metal is referred to as a metal sponge. The metal sponge generates or maintains the high vacuum by increasing the available active cryosorbing surface area. 4 figs

  10. Generation of miRNA sponge constructs

    NARCIS (Netherlands)

    Kluiver, Joost; Slezak-Prochazka, Izabella; Smigielska-Czepiel, Katarzyna; Halsema, Nancy; Kroesen, Bart-Jan; van den Berg, Anke

    2012-01-01

    MicroRNA (miRNA) sponges are RNA molecules with repeated miRNA antisense sequences that can sequester miRNAs from their endogenous targets and thus serve as a decoy. Stably expressed miRNA sponges are especially valuable for long-term loss-of-function studies and can be used in vitro and in vivo. We

  11. Macrofauna Associated with the Sponge Neopetrosia exigua ...

    African Journals Online (AJOL)

    in Marine Biology, Annamalai University, Parangipettai-608 502, Tamil Nadu, India. Keywords: Neopetrosia exigua, sponge, associated-fauna, species richness,. Mauritius, Indian Ocean. Abstract — The macrofaunal community associated with the sponge Neopetrosia exigua (Kirkpatrick, 1900) was studied across a ...

  12. Cell culture from sponges: pluripotency and immortality

    NARCIS (Netherlands)

    Caralt Bosch, de S.; Uriz, M.J.; Wijffels, R.H.

    2007-01-01

    Sponges are a source of compounds with potential pharmaceutical applications. In this article, methods of sponge cell culture for production of these bioactive compounds are reviewed, and new approaches for overcoming the problem of metabolite supply are examined. The use of embryos is proposed as a

  13. 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

  14. 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

  15. Genetic structure of the Caribbean giant barrel sponge Xestospongia muta using the I3-M11 partition of COI

    Science.gov (United States)

    López-Legentil, S.; Pawlik, J. R.

    2009-03-01

    In recent years, reports of sponge bleaching, disease, and subsequent mortality have increased alarmingly. Population recovery may depend strongly on colonization capabilities of the affected species. The giant barrel sponge Xestospongia muta is a dominant reef constituent in the Caribbean. However, little is known about its population structure and gene flow. The 5'-end fragment of the mitochondrial gene cytochrome oxidase subunit I is often used to address these kinds of questions, but it presents very low intraspecific nucleotide variability in sponges. In this study, the usefulness of the I3-M11 partition of COI to determine the genetic structure of X. muta was tested for seven populations from Florida, the Bahamas and Belize. A total of 116 sequences of 544 bp were obtained for the I3-M11 partition corresponding to four haplotypes. In order to make a comparison with the 5'-end partition, 10 sequences per haplotype were analyzed for this fragment. The 40 resulting sequences were of 569 bp and corresponded to two haplotypes. The nucleotide diversity of the I3-M11 partition (π = 0.00386) was higher than that of the 5'-end partition (π = 0.00058), indicating better resolution at the intraspecific level. Sponges with the most divergent external morphologies (smooth vs. digitate surface) had different haplotypes, while those with the most common external morphology (rough surface) presented a mixture of haplotypes. Pairwise tests for genetic differentiation among geographic locations based on F ST values showed significant genetic divergence between most populations, but this genetic differentiation was not due to isolation by distance. While limited larval dispersal may have led to differentiation among some of the populations, the patterns of genetic structure appear to be most strongly related to patterns of ocean currents. Therefore, hydrological features may play a major role in sponge colonization and need to be considered in future plans for management and

  16. Larval settlement: the role of surface topography for sessile coral reef invertebrates.

    Science.gov (United States)

    Whalan, Steve; Wahab, Muhammad A Abdul; Sprungala, Susanne; Poole, Andrew J; de Nys, Rocky

    2015-01-01

    For sessile marine invertebrates with complex life cycles, habitat choice is directed by the larval phase. Defining which habitat-linked cues are implicated in sessile invertebrate larval settlement has largely concentrated on chemical cues which are thought to signal optimal habitat. There has been less effort establishing physical settlement cues, including the role of surface microtopography. This laboratory based study tested whether surface microtopography alone (without chemical cues) plays an important contributing role in the settlement of larvae of coral reef sessile invertebrates. We measured settlement to tiles, engineered with surface microtopography (holes) that closely matched the sizes (width) of larvae of a range of corals and sponges, in addition to surfaces with holes that were markedly larger than larvae. Larvae from two species of scleractinian corals (Acropora millepora and Ctenactis crassa) and three species of coral reef sponges (Luffariella variabilis, Carteriospongia foliascens and Ircinia sp.,) were used in experiments. L. variabilis, A. millepora and C. crassa showed markedly higher settlement to surface microtopography that closely matched their larval width. C. foliascens and Ircinia sp., showed no specificity to surface microtopography, settling just as often to microtopography as to flat surfaces. The findings of this study question the sole reliance on chemical based larval settlement cues, previously established for some coral and sponge species, and demonstrate that specific physical cues (surface complexity) can also play an important role in larval settlement of coral reef sessile invertebrates.

  17. 21 CFR 880.2740 - Surgical sponge scale.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Surgical sponge scale. 880.2740 Section 880.2740... Devices § 880.2740 Surgical sponge scale. (a) Identification. A surgical sponge scale is a nonelectrically powered device used to weigh surgical sponges that have been used to absorb blood during surgery so that...

  18. Bacterial community profiles in low microbial abundance sponges

    KAUST Repository

    Giles, Emily

    2012-09-04

    It has long been recognized that sponges differ in the abundance of associated microorganisms, and they are therefore termed either \\'low microbial abundance\\' (LMA) or \\'high microbial abundance\\' (HMA) sponges. Many previous studies concentrated on the dense microbial communities in HMA sponges, whereas little is known about microorganisms in LMA sponges. Here, two LMA sponges from the Red Sea, two from the Caribbean and one from the South Pacific were investigated. With up to only five bacterial phyla per sponge, all LMA sponges showed lower phylum-level diversity than typical HMA sponges. Interestingly, each LMA sponge was dominated by a large clade within either Cyanobacteria or different classes of Proteobacteria. The overall similarity of bacterial communities among LMA sponges determined by operational taxonomic unit and UniFrac analysis was low. Also the number of sponge-specific clusters, which indicate bacteria specifically associated with sponges and which are numerous in HMA sponges, was low. A biogeographical or host-dependent distribution pattern was not observed. In conclusion, bacterial community profiles of LMA sponges are clearly different from profiles of HMA sponges and, remarkably, each LMA sponge seems to harbour its own unique bacterial community. © 2012 Federation of European Microbiological Societies.

  19. Artificial reefs and reef restoration in the Laurentian Great Lakes

    Science.gov (United States)

    McLean, Matthew W.; Roseman, Edward; Pritt, Jeremy J.; Kennedy, Gregory W.; Manny, Bruce A.

    2015-01-01

    We reviewed the published literature to provide an inventory of Laurentian Great Lakes artificial reef projects and their purposes. We also sought to characterize physical and biological monitoring for artificial reef projects in the Great Lakes and determine the success of artificial reefs in meeting project objectives. We found records of 6 artificial reefs in Lake Erie, 8 in Lake Michigan, 3 in Lakes Huron and Ontario, and 2 in Lake Superior. We found 9 reefs in Great Lakes connecting channels and 6 reefs in Great Lakes tributaries. Objectives of artificial reef creation have included reducing impacts of currents and waves, providing safe harbors, improving sport-fishing opportunities, and enhancing/restoring fish spawning habitats. Most reefs in the lakes themselves were incidental (not created purposely for fish habitat) or built to improve local sport fishing, whereas reefs in tributaries and connecting channels were more frequently built to benefit fish spawning. Levels of assessment of reef performance varied; but long-term monitoring was uncommon as was assessment of physical attributes. Artificial reefs were often successful at attracting recreational species and spawning fish; however, population-level benefits of artificial reefs are unclear. Stressors such as sedimentation and bio-fouling can limit the effectiveness of artificial reefs as spawning enhancement tools. Our investigation underscores the need to develop standard protocols for monitoring the biological and physical attributes of artificial structures. Further, long-term monitoring is needed to assess the benefits of artificial reefs to fish populations and inform future artificial reef projects.

  20. SARSTEINIA BABAI N. GEN., N. SP., A NEW PROBLEMATIC SPONGE (INOZOA? FROM THE LATE JURASSIC OF THE NORTHERN CALCAREOUS ALPS, AUSTRIA

    Directory of Open Access Journals (Sweden)

    FELIX SCHLAGINTWEIT

    2006-07-01

    Full Text Available The new problematic sponge Sarsteinia babai n. gen., n. sp. is described from the Kimmeridgian to Tithonian Plassen and Lärchberg Formations of the Northern Calcareous Alps of Austria. The type-locality is the Sarsteinalm north of Mount Hoher Sarstein in the Austrian Salzkammergut, other findings come from Mount Sandling, Mount Jainzen, Mount Trisselwand and the Litzlkogel-Gerhardstein-complex west of Lofer. Most findings can be attributed to a fore-reef to upper slope facies or slope-of-toe breccias, small fragments can occasionally also be found in the back-reef facies. The suprageneric systematic position of the new sponge is unknown so far since it shows morphological characteristics known from Inozoa but also from "stromatoporoids".

  1. The response of a boreal deep-sea sponge holobiont to acute thermal stress.

    Science.gov (United States)

    Strand, R; Whalan, S; Webster, N S; Kutti, T; Fang, J K H; Luter, H M; Bannister, R J

    2017-05-22

    Effects of elevated seawater temperatures on deep-water benthos has been poorly studied, despite reports of increased seawater temperature (up to 4 °C over 24 hrs) coinciding with mass mortality events of the sponge Geodia barretti at Tisler Reef, Norway. While the mechanisms driving these mortality events are unclear, manipulative laboratory experiments were conducted to quantify the effects of elevated temperature (up to 5 °C, above ambient levels) on the ecophysiology (respiration rate, nutrient uptake, cellular integrity and sponge microbiome) of G. barretti. No visible signs of stress (tissue necrosis or discolouration) were evident across experimental treatments; however, significant interactive effects of time and treatment on respiration, nutrient production and cellular stress were detected. Respiration rates and nitrogen effluxes doubled in responses to elevated temperatures (11 °C & 12 °C) compared to control temperatures (7 °C). Cellular stress, as measured through lysosomal destabilisation, was 2-5 times higher at elevated temperatures than for control temperatures. However, the microbiome of G. barretti remained stable throughout the experiment, irrespective of temperature treatment. Mortality was not evident and respiration rates returned to pre-experimental levels during recovery. These results suggest other environmental processes, either alone or in combination with elevated temperature, contributed to the mortality of G. barretti at Tisler reef.

  2. Evidence for Vertical Transmission of Bacterial Symbionts from Adult to Embryo in the Caribbean Sponge Svenzea zeai

    KAUST Repository

    Lee, O. O.

    2009-07-31

    The Caribbean reef sponge Svenzea zeai was previously found to contain substantial quantities of unicellular photosynthetic and autotrophic microbes in its tissues, but the identities of these symbionts and their method of transfer from adult to progeny are largely unknown. In this study, both a 16S rRNA gene-based fingerprinting technique (denaturing gradient gel electrophoresis [DGGE]) and clone library analysis were applied to compare the bacterial communities associated with adults and embryos of S. zeai to test the hypothesis of vertical transfer across generations. In addition, the same techniques were applied to the bacterial community from the seawater adjacent to adult sponges to test the hypothesis that water column bacteria could be transferred horizontally as sponge symbionts. Results of both DGGE and clone library analysis support the vertical transfer hypothesis in that the bacterial communities associated with sponge adults and embryos were highly similar to each other but completely different from those in the surrounding seawater. Sequencing of prominent DGGE bands and of clones from the libraries revealed that the bacterial communities associated with the sponge, whether adult or embryo, consisted of a large proportion of bacteria in the phyla Chloroflexi and Acidobacteria, while most of the sequences recovered from the community in the adjacent water column belonged to the class Alphaproteobacteria. Altogether, 21 monophyletic sequence clusters, comprising sequences from both sponge adults and embryos but not from the seawater, were identified. More than half of the sponge-derived sequences fell into these clusters. Comparison of sequences recovered in this study with those deposited in GenBank revealed that more than 75% of S. zeai-derived sequences were closely related to sequences derived from other sponge species, but none of the sequences recovered from the seawater column overlapped with those from adults or embryos of S. zeai. In

  3. Coral reefs and eutrophication

    International Nuclear Information System (INIS)

    Stambler, N.

    1999-01-01

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

  4. Otter Reef Extension, Density, and Calcification Data for 1792 to 1987

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  5. Flinders Reef Extension, Density, and Calcification Data for 1718 to 1991

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  6. Yankee Reef Extension, Density, and Calcification Data for 1888 to 1984

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  7. Agincourt Reef Extension, Density, and Calcification Data for 1779 to 1988

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  8. Stanley Reef Extension, Density, and Calcification Data for 1912 to 1985

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  9. Rib Reef Extension, Density, and Calcification Data for 1853 to 1983

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  10. Britomart Reef Extension, Density, and Calcification Data for 1574 to 1986

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  11. Abraham Reef Extension, Density, and Calcification Data for 1479 to 1985

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  12. Wheeler Reef Extension, Density, and Calcification Data for 1744 to 1984

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  13. Pandora Reef Extension, Density, and Calcification Data for 1875 to 1982

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  14. Sanctuary Reef Extension, Density, and Calcification Data for 1501 to 1984

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Extension, Density, and Calcification data from 35 Porites coral cores covering the entire length of the Great Barrier Reef, Australia. Data set contains 35...

  15. Can a sponge fractionate isotopes?

    Science.gov (United States)

    Patel, B; Patel, S; Balani, M C

    1985-03-22

    The study has unequivocally demonstrated that siliceous sponges Spirastrella cuspidifera and Prostylyssa foetida from the same microecological niche exhibit a high degree of species specificity, while accumulating a host of heavy metal ions (Ni, Cr, Cd, Sn, Ti, Mo, Zr). S. cuspidifera accumulated, in addition, 60Co and 63Ni, showing discrimination against other radionuclides, 137Cs and 131I, present in the ambient waters receiving controlled low level waste discharges from a B.W.R. nuclear power station. P. foetida, on the other hand, accumulated only 131I and showed discrimination against other radionuclides including 60Co, although the stable iodine concentrations in both the sponges were the same. The specific activity of 60Co (in becquerels per gram of 59Co) in S. cuspidifera and 131I (in becquerels per gram of 127I) in P. foetida were at least two orders of magnitude greater than in the ambient sea water. That of 63Ni (in becquerels per gram of 62Ni) in S. cuspidifera, on the other hand, was lower by two orders of magnitude than in either abiotic matrices from the same environment. Thus, not only did both the species show bioaccumulation of a specific element, but also preferential uptake of isotopes of the same element, though they were equally available for intake. Such differential uptake of isotopes can possibly be explained in terms of two quite different mechanisms operating, each applicable in a particular case. One is that the xenobiotic isotope enters the environment in a physicochemical form or as a complex different from that of its natural counterpart. If equilibration with the latter is slow, so that the organism acquires the xenobiotic in an unfamiliar chemical context, it may treat it as a chemically distinct entity so that its concentration factor differs from that of stable isotope, thus changing the specific activity. Alternatively, if the xenobiotic is present in the same chemical form as the stable isotope, the only way in which specific

  16. Coral Reef Guidance

    Science.gov (United States)

    Guidance prepared by EPA and Army Corps of Engineers concerning coral reef protection under the Clean Water Act, Marine Protection, Research, and Sanctuaries Act, Rivers and Harbors Act, and Federal Project Authorities.

  17. Antibacterial activity of the sponge Suberites domuncula and its primmorphs: Potential basis for epibacterial chemical defense

    Digital Repository Service at National Institute of Oceanography (India)

    Thakur, N; Hentschel, U.; Krasko, A; Pabel, C; Anil, A.C; Mueller, W.E.G.

    The epibacterial chemical defense of the marine sponge Suberites domuncula was explored by screening sponge extract, sponge primmorph (3-D aggregates containing proliferating cells) extract and sponge-associated as well as primmorph...

  18. AFSC/ABL: Salisbury Sound sponge recovery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1995, an area of the seafloor near Salisbury Sound was trawled to identify immediate effects on large, erect sponges and sea whips. Video transects were made in...

  19. Abdominal retained surgical sponges: CT appearance

    Energy Technology Data Exchange (ETDEWEB)

    Kalovidouris, A.; Kehagias, D.; Moulopoulos, L.; Gouliamos, A.; Pentea, S.; Vlahos, L. [Department of Radiology, University of Athens (Greece)

    1999-09-01

    Retention of surgical sponges is rare. They cause either an aseptic reaction without significant symptoms or an exudative reaction which results in early but nonspecific symptoms. Computed tomography is very useful for recognition of retained sponges. The appearance of retained sponges is widely variable. Air trapping into a surgical sponge results in the spongiform pattern which is characteristic but unfortunately uncommon. A low-density, high-density, or complex mass is found in the majority of cases, but these patterns are not specific. Sometimes, a thin high-density capsule may be seen. Rim or internal calcification is a rare finding. Finally, a radiopaque marker is not a reliable sign. Differentiation from abscess and hematoma is sometimes difficult. (orig.) With 11 figs., 12 refs.

  20. Abdominal retained surgical sponges: CT appearance

    International Nuclear Information System (INIS)

    Kalovidouris, A.; Kehagias, D.; Moulopoulos, L.; Gouliamos, A.; Pentea, S.; Vlahos, L.

    1999-01-01

    Retention of surgical sponges is rare. They cause either an aseptic reaction without significant symptoms or an exudative reaction which results in early but nonspecific symptoms. Computed tomography is very useful for recognition of retained sponges. The appearance of retained sponges is widely variable. Air trapping into a surgical sponge results in the spongiform pattern which is characteristic but unfortunately uncommon. A low-density, high-density, or complex mass is found in the majority of cases, but these patterns are not specific. Sometimes, a thin high-density capsule may be seen. Rim or internal calcification is a rare finding. Finally, a radiopaque marker is not a reliable sign. Differentiation from abscess and hematoma is sometimes difficult. (orig.)

  1. Antiviral lead compounds from marine sponges

    KAUST Repository

    Sagar, Sunil; Kaur, Mandeep; Minneman, Kenneth P.

    2010-01-01

    ). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due

  2. Chitosan: collagen sponges. In vitro mineralization

    International Nuclear Information System (INIS)

    Martins, Virginia da C.A.; Silva, Gustavo M.; Plepis, Ana Maria G.

    2011-01-01

    The regeneration of bone tissue is a problem that affects many people and scaffolds for bone tissue growth has been widely studied. The aim of this study was the in vitro mineralization of chitosan, chitosan:native collagen and chitosan:anionic collagen sponges. The sponges were obtained by lyophilization and mineralization was made by soaking the sponges in alternating solutions containing Ca 2+ and PO 4 3- . The mineralization was confirmed by infrared spectroscopy, energy dispersive X-ray and X-ray diffraction observing the formation of phosphate salts, possibly a carbonated hydroxyapatite since Ca/P=1.80. The degree of mineralization was obtained by thermogravimetry calculating the amount of residue at 750 deg C. The chitosan:anionic collagen sponge showed the highest degree of mineralization probably due to the fact that anionic collagen provides additional sites for interaction with the inorganic phase. (author)

  3. Some aspects of chemical ecology of the sponges of the Caribbean, Axinyssa ambrosia and Aplysina insularis

    International Nuclear Information System (INIS)

    Puyana Monica; Petrichtcheva, Natalia; Morales, Alicia; Duque Carmenza

    2002-01-01

    Axinyssamine hydrochloride (compound 1) was recently found in the marine sponge Axinyssa ambrosia at concentrations in the order of 10 mg/ml. Lethality assays using compound 1 against the coral Madracis mirabilis allowed determining that the mentioned compound is lethal to coral polyps at the natural concentration present in the sponge. Additionally, by performing exudation experiments in aquaria and chemical detection by HRGC-MS (scan and sim modes) it was found that the compounds ll-formamide-7β-H-eudesm-5-ene (2) and 4 α-formamidogorgon-ll-ene (3) are continually exuded by Axinyssa ambrosia creating a protective chemical barrier around the sponge. Exudation rates increase 3.80 and 2.47 fold respectively for each compound, under stress conditions or aggression. These results suggest that the sponge Axinyssa ambrosia may use the above-mentioned three metabolites as chemical defenses. Other experiments were carried out with the sponge Aplysina insularis in situ, under ecologically relevant conditions, with the purpose of determining if the chemical composition (Brominated metabolites) changes over variable time periods after inflicting wounds on the sponge surface. Metabolites were detected and identified by LC-MS. No evidence of chemical transformation of high molecular weight compounds into the compounds Aeroplysinin-l (4) and/or the dibromo cyclohexadienone (5) was obtained as a consequence of tissue damage, both in short (2,5 minutes) and long duration experiments (120 minutes). These results suggest that the conversion of high molecular weight compounds into small, active forms does not take place in Aplysina insularis as a chemical defense mechanism

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

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  5. The effect of local hydrodynamics on the spatial extent and morphology of cold-water coral habitats at Tisler Reef, Norway

    Science.gov (United States)

    De Clippele, L. H.; Huvenne, V. A. I.; Orejas, C.; Lundälv, T.; Fox, A.; Hennige, S. J.; Roberts, J. M.

    2018-03-01

    This study demonstrates how cold-water coral morphology and habitat distribution are shaped by local hydrodynamics, using high-definition video from Tisler Reef, an inshore reef in Norway. A total of 334 video frames collected on the north-west (NW) and south-east (SE) side of the reef were investigated for Lophelia pertusa coral cover and morphology and for the cover of the associated sponges Mycale lingua and Geodia sp. Our results showed that the SE side was a better habitat for L. pertusa (including live and dead colonies). Low cover of Geodia sp. was found on both sides of Tisler Reef. In contrast, Mycale lingua had higher percentage cover, especially on the NW side of the reef. Bush-shaped colonies of L. pertusa with elongated branches were the most abundant coral morphology on Tisler Reef. The highest abundance and density of this morphology were found on the SE side of the reef, while a higher proportion of cauliflower-shaped corals with short branches were found on the NW side. The proportion of very small L. pertusa colonies was also significantly higher on the SE side of the reef. The patterns in coral spatial distribution and morphology were related to local hydrodynamics—there were more frequent periods of downwelling currents on the SE side—and to the availability of suitable settling substrates. These factors make the SE region of Tisler Reef more suitable for coral growth. Understanding the impact of local hydrodynamics on the spatial extent and morphology of coral, and their relation to associated organisms such as sponges, is key to understanding the past and future development of the reef.

  6. 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

    2017-05-31

    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.

  7. EFISIENSI PENGGUNAAN TELUR DALAM PEMBUATAN SPONGE CAKE

    OpenAIRE

    Ida Ayu Putu Hemy Ekayani

    2011-01-01

    Penelitian ini bertujuan untuk membuat kue berpori (spong cake) dengan kualitas baik  dengan menggunakan jumlah telur minimal yang dibantu dengan penggunaan baking powder secara optimal untuk menurunkan biaya produksi yang disebabkan oleh mahalnya harga telur. Penelitian ini merupakan penelitian laboratorium (eksperimen). Analisis data dilakukan secara deskriptif. Hasil penelitian menunjukkan bahwa kualitas sponge cake terbaik dihasilkan dari dua variasi rancangan variasi kadar baking powder ...

  8. 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

  9. NOAA Coral Reef Watch Larval Connectivity, Florida Reef Tract

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Climate change threatens even the best-protected and most remote reefs. Reef recovery following catastrophic disturbance usually requires disturbed sites be reseeded...

  10. The role of the reef-dune system in coastal protection in Puerto Morelos (Mexico)

    Science.gov (United States)

    Franklin, Gemma L.; Torres-Freyermuth, Alec; Medellin, Gabriela; Allende-Arandia, María Eugenia; Appendini, Christian M.

    2018-04-01

    Reefs and sand dunes are critical morphological features providing natural coastal protection. Reefs dissipate around 90 % of the incident wave energy through wave breaking, whereas sand dunes provide the final natural barrier against coastal flooding. The storm impact on coastal areas with these features depends on the relative elevation of the extreme water levels with respect to the sand dune morphology. However, despite the importance of barrier reefs and dunes in coastal protection, poor management practices have degraded these ecosystems, increasing their vulnerability to coastal flooding. The present study aims to theoretically investigate the role of the reef-dune system in coastal protection under current climatic conditions at Puerto Morelos, located in the Mexican Caribbean Sea, using a widely validated nonlinear non-hydrostatic numerical model (SWASH). Wave hindcast information, tidal level, and a measured beach profile of the reef-dune system in Puerto Morelos are employed to estimate extreme runup and the storm impact scale for current and theoretical scenarios. The numerical results show the importance of including the storm surge when predicting extreme water levels and also show that ecosystem degradation has important implications for coastal protection against storms with return periods of less than 10 years. The latter highlights the importance of conservation of the system as a mitigation measure to decrease coastal vulnerability and infrastructure losses in coastal areas in the short to medium term. Furthermore, the results are used to evaluate the applicability of runup parameterisations for beaches to reef environments. Numerical analysis of runup dynamics suggests that runup parameterisations for reef environments can be improved by including the fore reef slope. Therefore, future research to develop runup parameterisations incorporating reef geometry features (e.g. reef crest elevation, reef lagoon width, fore reef slope) is warranted.

  11. Mesophotic bioerosion: Variability and structural impact on U.S. Virgin Island deep reefs

    Science.gov (United States)

    Weinstein, David K.; Smith, Tyler B.; Klaus, James S.

    2014-10-01

    Mesophotic reef corals, found 30-150 m below sea level, build complex structures that provide habitats for diverse ecosystems. Whereas bioerosion is known to impact the development and persistence of shallow reef structures, little is known regarding the extent of mesophotic bioerosion or how it might affect deeper reef geomorphology and carbonate accretion. Originally pristine experimental coral substrates and collected coral rubble were both used to investigate the variation and significance of mesophotic coral reef bioerosion south of St. Thomas, U.S. Virgin Islands. Bioerosion rates were calculated from experimental coral substrates exposed as framework for 1 and 2 years at four structurally distinct mesophotic coral reef habitats (between 30 and 45 m) as well as at a mid-shelf patch reef (21 m) and a shallow fringing patch reef (9 m). The long-term effects of macroboring were assessed by examining coral rubble collected at all sites. Overall, differences in bioerosional processes were found between shallow and mesophotic reefs. Increases in bioerosion on experimental substrates (amount of weight lost) were related to both decreasing seawater depth and increasing biomass of bioeroding parrotfish. Significant differences in coral skeleton bioerosion rates were also found between the transitional mesophotic reef zone (30-35 m) and the upper mesophotic reef zone (35-50 m) after 2 years of exposure, ranging from - 19.6 to 3.7 g/year. Total coral rubble macroboring was greater at most deep sites compared to shallower sites. Bioerosional grazing was found to dominate initial substrate modification in reefs 30.7 m and shallower, but sponges are believed to act as the main time-averaged long-term substrate bioeroders in reefs between 35 and 50 m. Although initial substrate bioerosion rates of a uniform substrate were relatively homogeneous in the 35-50 m depth zone, comparison of site composition suggests that mesophotic bioerosion will vary depending on the amount

  12. Global warming transforms coral reef assemblages.

    Science.gov (United States)

    Hughes, Terry P; Kerry, James T; Baird, Andrew H; Connolly, Sean R; Dietzel, Andreas; Eakin, C Mark; Heron, Scott F; Hoey, Andrew S; Hoogenboom, Mia O; Liu, Gang; McWilliam, Michael J; Pears, Rachel J; Pratchett, Morgan S; Skirving, William J; Stella, Jessica S; Torda, Gergely

    2018-04-01

    Global warming is rapidly emerging as a universal threat to ecological integrity and function, highlighting the urgent need for a better understanding of the impact of heat exposure on the resilience of ecosystems and the people who depend on them 1 . Here we show that in the aftermath of the record-breaking marine heatwave on the Great Barrier Reef in 2016 2 , corals began to die immediately on reefs where the accumulated heat exposure exceeded a critical threshold of degree heating weeks, which was 3-4 °C-weeks. After eight months, an exposure of 6 °C-weeks or more drove an unprecedented, regional-scale shift in the composition of coral assemblages, reflecting markedly divergent responses to heat stress by different taxa. Fast-growing staghorn and tabular corals suffered a catastrophic die-off, transforming the three-dimensionality and ecological functioning of 29% of the 3,863 reefs comprising the world's largest coral reef system. Our study bridges the gap between the theory and practice of assessing the risk of ecosystem collapse, under the emerging framework for the International Union for Conservation of Nature (IUCN) Red List of Ecosystems 3 , by rigorously defining both the initial and collapsed states, identifying the major driver of change, and establishing quantitative collapse thresholds. The increasing prevalence of post-bleaching mass mortality of corals represents a radical shift in the disturbance regimes of tropical reefs, both adding to and far exceeding the influence of recurrent cyclones and other local pulse events, presenting a fundamental challenge to the long-term future of these iconic ecosystems.

  13. A benthic survey of Aliwal Shoal and assessment of the effects of a wood pulp effluent on the reef

    International Nuclear Information System (INIS)

    Schleyer, Michael H. . E-mail schleyer@ori.org.za; Heikoop, Jeffrey M.; Risk, Michael J.

    2006-01-01

    Aliwal Shoal lies south of Durban in South Africa and has been the subject of recent bathymetric, seafloor and benthic surveys. ANOVA of the biological data revealed that the biota were uniformly distributed on the reef with the exception of encrusting sponges and algae on rock. The variations in distribution of these biota were significant and, in the case of the encrusting sponges, appeared to be related to the discharge of a wood pulp effluent. Further evidence of this was suggested by stable isotope analyses of representative organisms. The encrusting sponges were recommended as good candidates for further monitoring of the effects of the wood pulp effluent on Aliwal Shoal as the effluent pipeline has been extended

  14. Reef Visual Census (RVC) data.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Provide data on frequency of occurrence , density abundance, and length frequency of reef fish throughout Florida reef tract from 1978 forward.

  15. Residency and spatial use by reef sharks of an isolated seamount and its implications for conservation.

    Science.gov (United States)

    Barnett, Adam; Abrantes, Kátya G; Seymour, Jamie; Fitzpatrick, Richard

    2012-01-01

    Although marine protected areas (MPAs) are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia) are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (~14 km away) and one grey reef shark completed a round trip of ~250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef.

  16. Residency and spatial use by reef sharks of an isolated seamount and its implications for conservation.

    Directory of Open Access Journals (Sweden)

    Adam Barnett

    Full Text Available Although marine protected areas (MPAs are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (~14 km away and one grey reef shark completed a round trip of ~250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef.

  17. Residency and Spatial Use by Reef Sharks of an Isolated Seamount and Its Implications for Conservation

    Science.gov (United States)

    Barnett, Adam; Abrantes, Kátya G.; Seymour, Jamie; Fitzpatrick, Richard

    2012-01-01

    Although marine protected areas (MPAs) are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia) are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (∼14 km away) and one grey reef shark completed a round trip of ∼250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef. PMID:22615782

  18. Perspectives on the Great Amazon Reef: Extension, Biodiversity, and Threats

    Directory of Open Access Journals (Sweden)

    Ronaldo B. Francini-Filho

    2018-04-01

    Full Text Available Here we provide a broad overview of the Great Amazon Reef System (GARS based on the first-ever video surveys of the region. This footage supports four major hypotheses: (1 the GARS area may be six times larger than previously suggested (up to 56,000 km2; (2 the GARS may extend deeper than previously suggested (up to 220 m; (3 the GARS is composed of a greater complexity and diversity of habitats than previously recognized (e.g., reef platforms, reef walls, rhodolith beds, and sponge bottoms; and (4 the GARS represents a useful system to test whether a deep corridor connects the Caribbean Sea to the Southwest Atlantic Ocean. We also call attention to the urgent need to adopt precautionary conservation measures to protect the region in the face of increasing threats from extractive oil and gas practices. With less than 5% of the potential area of the GARS surveyed so far, more research will be required to inform a systematic conservation planning approach and determine how best to establish a network of marine protected areas. Such planning will be required to reconcile extractive activities with effective biodiversity conservation in the GARS.

  19. Antagonistic activity of marine sponges associated Actinobacteria

    Directory of Open Access Journals (Sweden)

    Selvakumar Dharmaraj

    2016-06-01

    Full Text Available Objective: To focus on the isolation and preliminary characterization of marine sponges associated Actinobacteria particularly Streptomyces species and also their antagonistic activities against bacterial and fungal pathogens. Methods: The sponges were collected from Kovalam and Vizhinjam port of south-west coast of Kerala, India. Isolation of strains was carried out from sponge extracts using international Streptomyces project media. For preliminary identification of the strains, morphological (mycelial colouration, soluble pigments, melanoid pigmentation, spore morphology, nutritional uptake (carbon utilisation, amonoacids influence, sodium chloride tolerance, physiological (pH, temperature and chemotaxonomical characterization were done. Antimicrobial studies were also carried out for the selected strains. Results: With the help of the spicule structures, the collected marine sponges were identified as Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis. Nearly 94 strains were primarily isolated from these sponges and further they were sub-cultured using international Streptomyces project media. The strains exhibited different mycelial colouration (aerial and substrate, soluble and melanoid pigmentations. The strains possessed three types of sporophore morphology namely rectus flexibilis, spiral and retinaculiaperti. Among the 94 isolates, seven exhibited antibacterial and antifungal activities with maximal zone of inhibition of 30 mm. The nutritional, physiological and chemotaxonomical characteristic study helped in the conventional identification of the seven strains and they all suggest that the strains to be grouped under the genus Streptomyces. Conclusions: The present study clearly helps in the preliminary identification of the isolates associated with marine sponges. Antagonistic activities prove the production of antimicrobial metabolites against the pathogens. Marine sponges associated Streptomyces are

  20. Thrombospondin 2-null mice display an altered brain foreign body response to polyvinyl alcohol sponge implants

    International Nuclear Information System (INIS)

    Tian Weiming; Kyriakides, Themis R

    2009-01-01

    Thrombospondin (TSP)-2 is a matricellular protein that participates in the processes of tissue repair and the foreign body response. In addition, TSP2 has been shown to influence synaptogenesis and recovery of the brain following stroke. In the present study we investigated the response following the implantation of polyvinyl alcohol (PVA) sponges in the brain. PVA sponges were implanted into the brain cortex of wild type and TSP2-null mice for a period of 4 and 8 weeks and the response was analyzed by histochemistry and quantitative immunohistochemistry. TSP2 expression was detected in the interstices of the sponge and co-localized with the extracellular matrix and astrocytes. PVA sponge invasion in TSP2-null mice was characterized by dense deposition of extracellular matrix and increased invasion of reactive astrocytes and macrophages/microglia. Furthermore, the angiogenic response was elevated and the detection of mouse serum albumin (MSA) in the brain cortex indicated excessive vessel leakage, suggesting that TSP2 plays a role in the repair/maintenance of the blood brain barrier. Finally, immunostaining demonstrated an increase in the levels of matrix metalloproteinase (MMP)-2 and MMP-9. Taken together, our observations support a role for TSP2 as critical determinant of the brain response to biomaterials.

  1. High energy density supercapacitors using macroporous kitchen sponges

    KAUST Repository

    Chen, Wei; Baby, Rakhi Raghavan; Alshareef, Husam N.

    2012-01-01

    Macroporous, low-cost and recyclable kitchen sponges are explored as effective electrode platforms for supercapacitor devices. A simple and scalable process has been developed to fabricate MnO 2-carbon nanotube (CNT)-sponge supercapacitor electrodes

  2. Primary hafnium metal sponge and other forms, approved standard 1973

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    A specification is presented covering virgin hafnium metal commonly designated as sponge because of its porous, sponge-like texture; it may also be in other forms such as chunklets. The specification does not cover crystal bar

  3. High-performance nanostructured supercapacitors on a sponge

    KAUST Repository

    Chen, Wei; Baby, Rakhi Raghavan; Hu, Liangbing; Xie, Xing; Cui, Yi; Alshareef, Husam N.

    2011-01-01

    A simple and scalable method has been developed to fabricate nanostructured MnO 2-carbon nanotube (CNT)-sponge hybrid electrodes. A novel supercapacitor, henceforth referred to as "sponge supercapacitor", has been fabricated using these hybrid

  4. Bacterial community profiles in low microbial abundance sponges

    KAUST Repository

    Giles, Emily; Kamke, Janine; Moitinho-Silva, Lucas; Taylor, Michael W.; Hentschel, Ute T E; Ravasi, Timothy; Schmitt, Susanne

    2012-01-01

    It has long been recognized that sponges differ in the abundance of associated microorganisms, and they are therefore termed either 'low microbial abundance' (LMA) or 'high microbial abundance' (HMA) sponges. Many previous studies concentrated

  5. First records of sponge-associated Actinomycetes from two coastal ...

    African Journals Online (AJOL)

    First records of sponge-associated Actinomycetes from two coastal sponges from Mauritius. Sandeep Shivram Beepat, Chandani Appadoo, Daniel Edgard Pierre Marie, Shamimtaz Bibi Sadally, Jose Pavao Mendes Paula, Kannan Sivakumar, Rashmi Ragothama Rao, Maryam Salah ...

  6. Modern coral reefs of western Atlantic: new geological perspective

    Energy Technology Data Exchange (ETDEWEB)

    MacIntyre, I.G.

    1988-11-01

    Contrary to popular belief of the late 1960s, western Atlantic Holocene reefs have a long history and are not feeble novice nearshore veneers that barely survived postglacial temperatures. Rather, the growth of these reefs kept pace with the rising seas of the Holocene transgression and their development was, for the most part, controlled by offshore wave-energy conditions and the relationship between changing sea levels and local shelf topography. Thus, the outer shelves of the eastern Caribbean in areas of high energy have relict reefs consisting predominantly of Acropora palmata, a robust shallow-water coral. The flooding of adjacent shelves during the postglacial transgression introduced stress conditions that terminated the growth of these reefs. When, about 7000 yr ago, shelf-water conditions improved, scattered deeper water coral communities reestablished themselves on these stranded shelf-edge reefs, and fringing and bank-barrier reefs began to flourish in shallow coastal areas. At the same time, the fragile and rapidly growing Acropora cervicornis and other corals flourished at greater depths on the more protected shelves of the western Caribbean and the Gulf of Mexico. As a result, late Holocene buildups more than 30 m thick developed in those areas. 7 figures.

  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. Property Assessment of Sponge Cake Added with Egg Replacer

    OpenAIRE

    Yaqiang He; Linlin Wang; Qian Lu

    2015-01-01

    Chicken egg which is always used in sponge cake production is likely to deteriorate during storage or transportation. This weakness prevents the wide use of chicken egg in sponge cake making. In order to solve this problem, egg replacer has been developed. In this study, effect of egg replacer on the property of sponge cake was analyzed. The result indicated egg replacer could improve the yield rate and specific volume of sponge cake. However, high content of egg replacer would negatively imp...

  9. 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.

  10. Carbon conversion and metabolic rate in two marine sponges

    NARCIS (Netherlands)

    Koopmans, M.; Van Rijswijk, P.; Martens, D.; Egorova-Zachernyuk, T.A.; Middelburg, J.J.; Wijffels, R.H.

    2011-01-01

    The carbon metabolism of two marine sponges, Haliclona oculata and Dysidea avara, has been studied using a 13C isotope pulse-chase approach. The sponges were fed 13C-labeled diatoms (Skeletonema costatum) for 8 h and they took up between 75 and 85%. At different times, sponges were sampled for total

  11. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of this...

  12. Coral reef ecosystem

    Digital Repository Service at National Institute of Oceanography (India)

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

    ), on submerged banks like Gave shani bank (13°24'N; 73°45'E) (Nair and Qasim 1978) andSidere~ko Bank (13°43.5' N; 73°42'E) (Rao 1972) and as stray individual units off Visakhapatnam (Bakus, G. personal communication) and Pondicherry (Ramesh, A. personal... 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...

  13. Processes Driving Natural Acidification of Western Pacific Coral Reef Waters

    Science.gov (United States)

    Shamberger, K. E.; Cohen, A. L.; Golbuu, Y.; McCorkle, D. C.; Lentz, S. J.; Barkley, H. C.

    2013-12-01

    Rising levels of atmospheric carbon dioxide (CO2) are acidifying the oceans, reducing seawater pH, aragonite saturation state (Ωar) and the availability of carbonate ions (CO32-) that calcifying organisms use to build coral reefs. Today's most extensive reef ecosystems are located where open ocean CO32- concentration ([CO32-]) and Ωar exceed 200 μmol kg-1 and 3.3, respectively. However, high rates of biogeochemical cycling and long residence times of water can result in carbonate chemistry conditions within coral reef systems that differ greatly from those of nearby open ocean waters. In the Palauan archipelago, water moving across the reef platform is altered by both biological and hydrographic processes that combine to produce seawater pH, Ωar, [CO32-] significantly lower than that of open ocean source water. Just inshore of the barrier reefs, average Ωar values are 0.2 to 0.3 and pH values are 0.02 to 0.03 lower than they are offshore, declining further as water moves across the back reef, lagoon and into the meandering bays and inlets that characterize the Rock Islands. In the Rock Island bays, coral communities inhabit seawater with average Ωar values of 2.7 or less, and as low as 1.9. Levels of Ωar as low as these are not predicted to occur in the western tropical Pacific open ocean until near the end of the century. Calcification by coral reef organisms is the principal biological process responsible for lowering Ωar and pH, accounting for 68 - 99 % of the difference in Ωar between offshore source water and reef water at our sites. However, in the Rock Island bays where Ωar is lowest, CO2 production by net respiration contributes between 17 - 30 % of the difference in Ωar between offshore source water and reef water. Furthermore, the residence time of seawater in the Rock Island bays is much longer than at the well flushed exposed sites, enabling calcification and respiration to drive Ωar to very low levels despite lower net ecosystem

  14. Think like a sponge: The genetic signal of sensory cells in sponges.

    Science.gov (United States)

    Mah, Jasmine L; Leys, Sally P

    2017-11-01

    A complex genetic repertoire underlies the apparently simple body plan of sponges. Among the genes present in poriferans are those fundamental to the sensory and nervous systems of other animals. Sponges are dynamic and sensitive animals and it is intuitive to link these genes to behaviour. The proposal that ctenophores are the earliest diverging metazoan has led to the question of whether sponges possess a 'pre-nervous' system or have undergone nervous system loss. Both lines of thought generally assume that the last common ancestor of sponges and eumetazoans possessed the genetic modules that underlie sensory abilities. By corollary extant sponges may possess a sensory cell homologous to one present in the last common ancestor, a hypothesis that has been studied by gene expression. We have performed a meta-analysis of all gene expression studies published to date to explore whether gene expression is indicative of a feature's sensory function. In sponges we find that eumetazoan sensory-neural markers are not particularly expressed in structures with known sensory functions. Instead it is common for these genes to be expressed in cells with no known or uncharacterized sensory function. Indeed, many sensory-neural markers so far studied are expressed during development, perhaps because many are transcription factors. This suggests that the genetic signal of a sponge sensory cell is dissimilar enough to be unrecognizable when compared to a bilaterian sensory or neural cell. It is possible that sensory-neural markers have as yet unknown functions in sponge cells, such as assembling an immunological synapse in the larval globular cell. Furthermore, the expression of sensory-neural markers in non-sensory cells, such as adult and larval epithelial cells, suggest that these cells may have uncharacterized sensory functions. While this does not rule out the co-option of ancestral sensory modules in later evolving groups, a distinct genetic foundation may underlie the

  15. Understanding Resilience in a Vulnerable Industry: the Case of Reef Tourism in Australia

    Directory of Open Access Journals (Sweden)

    Duan Biggs

    2011-03-01

    Full Text Available Understanding the resilience of vulnerable sectors of social-ecological systems is critical in an era of escalating global change. The coral reef tourism sector is highly vulnerable not only to ecological effects of climate change and other anthropogenic disturbances on reefs, but also to shocks such as economic recession and energy price escalation. Commercial tourism enterprises are key players in reef tourism in Australia and elsewhere. However, the factors that confer resilience to reef-based tourism enterprises, or the reef tourism sector more broadly, in the face of large disturbances have not been investigated to date. This paper empirically examines the perceived resilience of reef tourism enterprises on Australia's Great Barrier Reef to large disturbances or shocks. Binary logistic regression analysis of two measures of enterprise resilience demonstrates the importance of human capital in strengthening enterprise resilience. Lifestyle identity, measured as the extent to which owners and senior managers are active in reef tourism as a lifestyle choice, is positively related to enterprise resilience. Finally, reef tourism enterprises indicate that financial and marketing support are the most important actions that government can take to support enterprises in the face of a large shock.

  16. Contrasting movements and connectivity of reef-associated sharks using acoustic telemetry: implications for management.

    Science.gov (United States)

    Espinoza, Mario; Lédée, Elodie J I; Simpfendorfer, Colin A; Tobin, Andrew J; Heupel, Michelle R

    2015-12-01

    Understanding the efficacy of marine protected areas (MPAs) for wide-ranging predators is essential to designing effective management and conservation approaches. The use of acoustic monitoring and network analysis can improve our understanding of the spatial ecology and functional connectivity of reef-associated species, providing a useful approach for reef-based conservation planning. This study compared and contrasted the movement and connectivity of sharks with different degrees of reef association. We examined the residency, dispersal, degree of reef connectivity, and MPA use of grey reef (Carcharhinus amblyrhynchos), silvertip (C. albimarginatus), and bull (C. leucas) sharks monitored in the central Great Barrier Reef (GBR). An array of 56 acoustic receivers was used to monitor shark movements on 17 semi-isolated reefs. Carcharhinus amblyrhynchos and C. albimarginatus were detected most days at or near their tagging reef. However, while C. amblyrhynchos spent 80% of monitoring days in the array, C. albimarginatus was only detected 50% of the time. Despite both species moving similar distances (sharks like C. leucas, a combination of spatial planning and other alternative measures is critical. Our findings demonstrate that acoustic monitoring can serve as a useful platform for designing more effective MPA networks for reef predators displaying a range of movement patterns.

  17. 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

  18. Acute ecotoxicology of natural oil and gas condensate to coral reef larvae.

    Science.gov (United States)

    Negri, Andrew P; Brinkman, Diane L; Flores, Florita; Botté, Emmanuelle S; Jones, Ross J; Webster, Nicole S

    2016-02-19

    Risks posed by oil spills to coral reefs are difficult to evaluate, partially due to the absence of studies that adequately assess toxicity to relevant coral reef species. Here we experimentally tested the acute toxicity of condensate, representing a fraction of light crude oil, to coral (Acropora tenuis) and sponge (Rhopaloeides odorabile) larvae. The metamorphosis of coral larvae was inhibited at total petroleum aromatic hydrocarbon (TPAH) concentrations of water accommodated fractions (WAF) as low as 103 μg l(-1), similar to concentrations detected in seawater following large spills. The sensitivity of coral larvae increased by 40% when co-exposed to UV light that they might encounter in shallow reefal systems. Condensate WAF was more toxic to coral larvae than predicted by summing the toxicity of its main components (benzene, toluene, p-xylene and napthalene). In contrast, the sensitivity of sponge larvae to condensate WAF (>10,000 μg l(-1) TPAH) was far less than coral in the presence and absence of UV, but similar to that of other marine invertebrates. While these results highlight the relative sensitivity of coral larvae to oil, further research is needed to better understand and predict the impacts and risks posed by hydrocarbons to tropical reef systems.

  19. 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...

  20. Diverse coral communities in naturally acidified waters of a Western Pacific reef

    Science.gov (United States)

    Shamberger, Kathryn E. F.; Cohen, Anne L.; Golbuu, Yimnang; McCorkle, Daniel C.; Lentz, Steven J.; Barkley, Hannah C.

    2014-01-01

    Anthropogenic carbon dioxide emissions are acidifying the oceans, reducing the concentration of carbonate ions ([CO32-]) that calcifying organisms need to build and cement coral reefs. To date, studies of a handful of naturally acidified reef systems reveal depauperate communities, sometimes with reduced coral cover and calcification rates, consistent with results of laboratory-based studies. Here we report the existence of highly diverse, coral-dominated reef communities under chronically low pH and aragonite saturation state (Ωar). Biological and hydrographic processes change the chemistry of the seawater moving across the barrier reefs and into Palau's Rock Island bays, where levels of acidification approach those projected for the western tropical Pacific open ocean by 2100. Nevertheless, coral diversity, cover, and calcification rates are maintained across this natural acidification gradient. Identifying the combination of biological and environmental factors that enable these communities to persist could provide important insights into the future of coral reefs under anthropogenic acidification.

  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. © 2016 John Wiley & Sons Ltd/CNRS.

  2. Wool fibril sponges with perspective biomedical applications

    International Nuclear Information System (INIS)

    Patrucco, A.; Cristofaro, F.; Simionati, M.; Zoccola, M.; Bruni, G.; Fassina, L.; Visai, L.; Magenes, G.

    2016-01-01

    Sheep's wool was used as a natural source to prepare keratin microfibril sponges for scaffolding, by disruption of the histological structure of the fibres through mild alkali treatment, followed by ultrasonication, casting and salt-leaching. The wool sponges showed highly interconnected porosity (93%) and contain intrinsic sites of cellular recognition that mimic the extracellular matrix (ECM). They displayed good thermal and water stability due to the conversion of disulphide cystine bonds into shorter monosulphide lanthionine intermolecular bonds, but significantly swelled in water, because of the high hydrophilicity and porosity, with a volume increasing up to 38%. Nevertheless, sponges were stable in water without structural changes, with a neutral pH in aqueous media, and showed excellent resilience to repeated compression stresses. According to in vitro biocompatibility assays, wool fibril sponges showed a good cell adhesion and proliferation as proved by MTT, FDA assays and SEM observations. The unique structure of the cortical cell network made by wool keratin proteins with controlled-size macro-porosity suitable for cell guesting, and nutrient feeding, provides an excellent scaffold for future tissue engineering applications. - Highlights: • Scaffolds were prepared from wool exploiting the fibres' histology structure. • The scaffold showed high interconnected micro- and macro-porosity. • The microscopic structure is very similar to the extracellular bone matrix. • Scaffolds reversibly swell in water with high resilience to repeated compression. • Composites were cytocompatible and supported the growth of SAOS-2 cell line.

  3. Electron beam melting of sponge titanium

    International Nuclear Information System (INIS)

    Kanayama, Hiroshi; Kusamichi, Tatsuhiko; Muraoka, Tetsuhiro; Onouye, Toshio; Nishimura, Takashi

    1991-01-01

    Fundamental investigations were done on electron beam (EB) melting of sponge titanium by using 80 kW EB melting furnace. Results obtained are as follows: (1) To increase the melting yield of titanium in EB melting of sponge titanium, it is important to recover splashed metal by installation of water-cooled copper wall around the hearth and to decrease evaporation loss of titanium by keeping the surface temperature of molten metal just above the melting temperature of titanium without local heating. (2) Specific power consumption of drip melting of pressed sponge titanium bar and hearth melting of sponge titanium are approximately 0.9 kWh/kg-Ti and 0.5-0.7 kWh/kg-Ti, respectively. (3) Ratios of the heat conducted to water-cooled mould in the drip melting and to water-cooled hearth in the hearth melting to the electron beam input power are 50-65% and 60-65%, respectively. (4) Surface defects of EB-melted ingots include rap which occurs when the EB output is excessively great, and transverse cracks when the EB output is excessively small. To prevent surface defects, the up-down withdrawal method is effective. (author)

  4. EFISIENSI PENGGUNAAN TELUR DALAM PEMBUATAN SPONGE CAKE

    Directory of Open Access Journals (Sweden)

    Ida Ayu Putu Hemy Ekayani

    2011-07-01

    Full Text Available Penelitian ini bertujuan untuk membuat kue berpori (spong cake dengan kualitas baik  dengan menggunakan jumlah telur minimal yang dibantu dengan penggunaan baking powder secara optimal untuk menurunkan biaya produksi yang disebabkan oleh mahalnya harga telur. Penelitian ini merupakan penelitian laboratorium (eksperimen. Analisis data dilakukan secara deskriptif. Hasil penelitian menunjukkan bahwa kualitas sponge cake terbaik dihasilkan dari dua variasi rancangan variasi kadar baking powder dan telur yakni resep pertama dengan formulasi tepung terigu 100 gram, baking powder 6 gram, telur 100 gram, lemak 75 gram, dan tanpa penambahaan air; dan resep ke dua dengan formulasi tepung terigu 100 gram, baking powder 2 gram, telur 80 gram, lemak 75 gram, dan air 16 gram. Jumlah telur yang digunakaan dalam kedua resep tersebut cukup jauh berkurang dari resep umum yang menggunakan 180 gram telur untuk 100 gram tepung terigu. Temuan penelitian ini akan berimplikasi pada sponge cake dengan harga yang lebih murah, tetapi dengan kualitas yang tetap relatif baik dapat dihadirkan ke pasar.   Kata-kata kunci: spong cake,  kualitas, baking powder, biaya produksi

  5. Wool fibril sponges with perspective biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Patrucco, A., E-mail: a.patrucco@bi.ismac.cnr.it [CNR-ISMAC, Italian National Research Council, Institute for Macromolecular Studies, Corso G. Pella 16, 13900, Biella (Italy); Cristofaro, F., E-mail: francesco.cristofaro01@universitadipavia.it [Department of Molecular Medicine, INSTM UdR of Pavia, University of Pavia, Viale Taramelli 3/B, 27100, Pavia (Italy); Centre for Health Technologies (CHT), University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Simionati, M., E-mail: m.simionati@bi.ismac.cnr.it [CNR-ISMAC, Italian National Research Council, Institute for Macromolecular Studies, Corso G. Pella 16, 13900, Biella (Italy); Zoccola, M., E-mail: m.zoccola@bi.ismac.cnr.it [CNR-ISMAC, Italian National Research Council, Institute for Macromolecular Studies, Corso G. Pella 16, 13900, Biella (Italy); Bruni, G., E-mail: giovanna.bruni@unipv.it [Department of Chemistry, — Physical-Chemistry Section, University of Pavia, Viale Taramelli 16, 27100, Pavia (Italy); Fassina, L., E-mail: lorenzo.fassina@unipv.it [Centre for Health Technologies (CHT), University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Visai, L., E-mail: livia.visai@unipv.it [Department of Molecular Medicine, INSTM UdR of Pavia, University of Pavia, Viale Taramelli 3/B, 27100, Pavia (Italy); Centre for Health Technologies (CHT), University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri Foundation, IRCCS, Via S. Boezio, 28, 27100, Pavia (Italy); Magenes, G., E-mail: giovanni.magenes@unipv.it [Centre for Health Technologies (CHT), University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 1, 27100, Pavia (Italy); and others

    2016-04-01

    Sheep's wool was used as a natural source to prepare keratin microfibril sponges for scaffolding, by disruption of the histological structure of the fibres through mild alkali treatment, followed by ultrasonication, casting and salt-leaching. The wool sponges showed highly interconnected porosity (93%) and contain intrinsic sites of cellular recognition that mimic the extracellular matrix (ECM). They displayed good thermal and water stability due to the conversion of disulphide cystine bonds into shorter monosulphide lanthionine intermolecular bonds, but significantly swelled in water, because of the high hydrophilicity and porosity, with a volume increasing up to 38%. Nevertheless, sponges were stable in water without structural changes, with a neutral pH in aqueous media, and showed excellent resilience to repeated compression stresses. According to in vitro biocompatibility assays, wool fibril sponges showed a good cell adhesion and proliferation as proved by MTT, FDA assays and SEM observations. The unique structure of the cortical cell network made by wool keratin proteins with controlled-size macro-porosity suitable for cell guesting, and nutrient feeding, provides an excellent scaffold for future tissue engineering applications. - Highlights: • Scaffolds were prepared from wool exploiting the fibres' histology structure. • The scaffold showed high interconnected micro- and macro-porosity. • The microscopic structure is very similar to the extracellular bone matrix. • Scaffolds reversibly swell in water with high resilience to repeated compression. • Composites were cytocompatible and supported the growth of SAOS-2 cell line.

  6. Lipid contents of the sponge Haliclona sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Das, B.; Kamat, S.Y.

    Several fatty acids, sterols, batyl alcohol and its analogs and an N-acylated sphingosine (ceramide) have been isolated from the lipid fraction of the extract of the sponge Haliclona sp. The major sterol is found to be cholesterol (54%), followed...

  7. Oceanic forcing of coral reefs.

    Science.gov (United States)

    Lowe, Ryan J; Falter, James L

    2015-01-01

    Although the oceans play a fundamental role in shaping the distribution and function of coral reefs worldwide, a modern understanding of the complex interactions between ocean and reef processes is still only emerging. These dynamics are especially challenging owing to both the broad range of spatial scales (less than a meter to hundreds of kilometers) and the complex physical and biological feedbacks involved. Here, we review recent advances in our understanding of these processes, ranging from the small-scale mechanics of flow around coral communities and their influence on nutrient exchange to larger, reef-scale patterns of wave- and tide-driven circulation and their effects on reef water quality and perceived rates of metabolism. We also examine regional-scale drivers of reefs such as coastal upwelling, internal waves, and extreme disturbances such as cyclones. Our goal is to show how a wide range of ocean-driven processes ultimately shape the growth and metabolism of coral reefs.

  8. Allelopathy in the tropical alga Lobophora variegata (Phaeophyceae): mechanistic basis for a phase shift on mesophotic coral reefs?

    Science.gov (United States)

    Slattery, Marc; Lesser, Michael P

    2014-06-01

    Macroalgal phase shifts on Caribbean reefs have been reported with increasing frequency, and recent reports of these changes on mesophotic coral reefs have raised questions regarding the mechanistic processes behind algal population expansions to deeper depths. The brown alga Lobophora variegata is a dominant species on many shallow and deep coral reefs of the Caribbean and Pacific, and it increased in percent cover (>50%) up to 61 m on Bahamian reefs following the invasion of the lionfish Pterois volitans. We examined the physiological and ecological constraints contributing to the spread of Lobophora on Bahamian reefs across a mesophotic depth gradient from 30 to 61 m, pre- and post-lionfish invasion. Results indicate that there were no physiological limitations to the depth distribution of Lobophora within this range prior to the lionfish invasion. Herbivory by acanthurids and scarids in algal recruitment plots at mesophotic depths was higher prior to the lionfish invasion, and Lobophora chemical defenses were ineffective against an omnivorous fish species. In contrast, Lobophora exhibited significant allelopathic activity against the coral Montastraea cavernosa and the sponge Agelas clathrodes in laboratory assays. These data indicate that when lionfish predation on herbivorous fish released Lobophora from grazing pressure at depth, Lobophora expanded its benthic cover to a depth of 61 m, where it replaced the dominant coral and sponge species. Our results suggest that this chemically defended alga may out-compete these species in situ, and that mesophotic reefs may be further impacted in the near future as Lobophora continues to expand to its compensation point. © 2013 Phycological Society of America.

  9. Actinomycetes from red sea sponges: Sources for chemical and phylogenetic diversity

    KAUST Repository

    Abdelmohsen, Usama Ramadan

    2014-05-12

    The diversity of actinomycetes associated with marine sponges collected off Fsar Reef (Saudi Arabia) was investigated in the present study. Forty-seven actinomycetes were cultivated and phylogenetically identified based on 16S rRNA gene sequencing and were assigned to 10 different actinomycete genera. Eight putatively novel species belonging to genera Kocuria, Mycobacterium, Nocardia, and Rhodococcus were identified based on sequence similarity values below 98.2% to other 16S rRNA gene sequences available in the NCBI database. PCR-based screening for biosynthetic genes including type I and type II polyketide synthases (PKS-I, PKS-II) as well as nonribosomal peptide synthetases (NRPS) showed that 20 actinomycete isolates encoded each at least one type of biosynthetic gene. The organic extracts of nine isolates displayed bioactivity against at least one of the test pathogens, which were Gram-positive and Gram-negative bacteria, fungi, human parasites, as well as in a West Nile Virus protease enzymatic assay. These results emphasize that marine sponges are a prolific resource for novel bioactive actinomycetes with potential for drug discovery. 2014 by the authors; licensee MDPI.

  10. Actinomycetes from red sea sponges: Sources for chemical and phylogenetic diversity

    KAUST Repository

    Abdelmohsen, Usama Ramadan; Yang, Chen; Horn, Hannes; Hajjar, Dina A.; Ravasi, Timothy; Hentschel, Ute

    2014-01-01

    The diversity of actinomycetes associated with marine sponges collected off Fsar Reef (Saudi Arabia) was investigated in the present study. Forty-seven actinomycetes were cultivated and phylogenetically identified based on 16S rRNA gene sequencing and were assigned to 10 different actinomycete genera. Eight putatively novel species belonging to genera Kocuria, Mycobacterium, Nocardia, and Rhodococcus were identified based on sequence similarity values below 98.2% to other 16S rRNA gene sequences available in the NCBI database. PCR-based screening for biosynthetic genes including type I and type II polyketide synthases (PKS-I, PKS-II) as well as nonribosomal peptide synthetases (NRPS) showed that 20 actinomycete isolates encoded each at least one type of biosynthetic gene. The organic extracts of nine isolates displayed bioactivity against at least one of the test pathogens, which were Gram-positive and Gram-negative bacteria, fungi, human parasites, as well as in a West Nile Virus protease enzymatic assay. These results emphasize that marine sponges are a prolific resource for novel bioactive actinomycetes with potential for drug discovery. 2014 by the authors; licensee MDPI.

  11. Biofouling of inlet pipes affects water quality in running seawater aquaria and compromises sponge cell proliferation

    Directory of Open Access Journals (Sweden)

    Brittany E. Alexander

    2015-12-01

    Full Text Available Marine organism are often kept, cultured, and experimented on in running seawater aquaria. However, surprisingly little attention is given to the nutrient composition of the water flowing through these systems, which is generally assumed to equal in situ conditions, but may change due to the presence of biofouling organisms. Significantly lower bacterial abundances and higher inorganic nitrogen species (nitrate, nitrite, and ammonium were measured in aquarium water when biofouling organisms were present within a 7-year old inlet pipe feeding a tropical reef running seawater aquaria system, compared with aquarium water fed by a new, biofouling-free inlet pipe. These water quality changes are indicative of the feeding activity and waste production of the suspension- and filter-feeding communities found in the old pipe, which included sponges, bivalves, barnacles, and ascidians. To illustrate the physiological consequences of these water quality changes on a model organism kept in the aquaria system, we investigated the influence of the presence and absence of the biofouling community on the functioning of the filter-feeding sponge Halisarca caerulea, by determining its choanocyte (filter cell proliferation rates. We found a 34% increase in choanocyte proliferation rates following the replacement of the inlet pipe (i.e., removal of the biofouling community. This indicates that the physiological functioning of the sponge was compromised due to suboptimal food conditions within the aquarium resulting from the presence of the biofouling organisms in the inlet pipe. This study has implications for the husbandry and performance of experiments with marine organisms in running seawater aquaria systems. Inlet pipes should be checked regularly, and replaced if necessary, in order to avoid excessive biofouling and to approach in situ water quality.

  12. Biofouling of inlet pipes affects water quality in running seawater aquaria and compromises sponge cell proliferation.

    Science.gov (United States)

    Alexander, Brittany E; Mueller, Benjamin; Vermeij, Mark J A; van der Geest, Harm H G; de Goeij, Jasper M

    2015-01-01

    Marine organism are often kept, cultured, and experimented on in running seawater aquaria. However, surprisingly little attention is given to the nutrient composition of the water flowing through these systems, which is generally assumed to equal in situ conditions, but may change due to the presence of biofouling organisms. Significantly lower bacterial abundances and higher inorganic nitrogen species (nitrate, nitrite, and ammonium) were measured in aquarium water when biofouling organisms were present within a 7-year old inlet pipe feeding a tropical reef running seawater aquaria system, compared with aquarium water fed by a new, biofouling-free inlet pipe. These water quality changes are indicative of the feeding activity and waste production of the suspension- and filter-feeding communities found in the old pipe, which included sponges, bivalves, barnacles, and ascidians. To illustrate the physiological consequences of these water quality changes on a model organism kept in the aquaria system, we investigated the influence of the presence and absence of the biofouling community on the functioning of the filter-feeding sponge Halisarca caerulea, by determining its choanocyte (filter cell) proliferation rates. We found a 34% increase in choanocyte proliferation rates following the replacement of the inlet pipe (i.e., removal of the biofouling community). This indicates that the physiological functioning of the sponge was compromised due to suboptimal food conditions within the aquarium resulting from the presence of the biofouling organisms in the inlet pipe. This study has implications for the husbandry and performance of experiments with marine organisms in running seawater aquaria systems. Inlet pipes should be checked regularly, and replaced if necessary, in order to avoid excessive biofouling and to approach in situ water quality.

  13. Mapping coral and sponge habitats on a shelf-depth environment using multibeam sonar and ROV video observations: Learmonth Bank, northern British Columbia, Canada

    Science.gov (United States)

    Neves, Bárbara M.; Du Preez, Cherisse; Edinger, Evan

    2014-01-01

    Efforts to locate and map deep-water coral and sponge habitats are essential for the effective management and conservation of these vulnerable marine ecosystems. Here we test the applicability of a simple multibeam sonar classification method developed for fjord environments to map the distribution of shelf-depth substrates and gorgonian coral- and sponge-dominated biotopes. The studied area is a shelf-depth feature Learmonth Bank, northern British Columbia, Canada and the method was applied aiming to map primarily non-reef forming coral and sponge biotopes. Aside from producing high-resolution maps (5 m2 raster grid), biotope-substrate associations were also investigated. A multibeam sonar survey yielded bathymetry, acoustic backscatter strength and slope. From benthic video transects recorded by remotely operated vehicles (ROVs) six primary substrate types and twelve biotope categories were identified, defined by the primary sediment and dominant biological structure, respectively. Substrate and biotope maps were produced using a supervised classification mostly based on the inter-quartile range of the acoustic variables for each substrate type and biotope. Twenty-five percent of the video observations were randomly reserved for testing the classification accuracy. The dominant biotope-defining corals were red tree coral Primnoa pacifica and small styasterids, of which Stylaster parageus was common. Demosponges and hexactinellid sponges were frequently observed but no sponge reefs were observed. The substrate classification readily distinguished fine sediment, Sand and Bedrock from the other substrate types, but had greater difficulty distinguishing Bedrock from Boulders and Cobble. The biotope classification accurately identified Gardens (dense aggregations of sponges and corals) and Primnoa-dominated biotopes (67% accuracy), but most other biotopes had lower accuracies. There was a significant correspondence between Learmonth's biotopes and substrate types

  14. Antiviral lead compounds from marine sponges

    KAUST Repository

    Sagar, Sunil

    2010-10-11

    Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. 2010 by the authors; licensee MDPI.

  15. Temporary refugia for coral reefs in a warming world

    Science.gov (United States)

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

    2013-05-01

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

  16. Diffusive boundary layers and photosynthesis of the epilithic algal community of coral reefs

    DEFF Research Database (Denmark)

    Larkum, Anthony W.D.; Koch, Eva-Maria W.; Kühl, Michael

    2003-01-01

    The effects of mass transfer resistance due to the presence of a diffusive boundary layer on the photosynthesis of the epilithic algal community (EAC) of a coral reef were studied. Photosynthesis and respiration of the EAC of dead coral surfaces were investigated for samples from two locations......: the Gulf of Aqaba, Eilat (Israel), and One Tree Reef on the Great Barrier Reef (Australia). Microsensors were used to measure O2 and pH at the EAC surface and above. Oxygen profiles in the light and dark indicated a diffusive boundary layer (DBL) thickness of 180–590 µm under moderate flow (~0.08 m s-1...

  17. Coral Reefs: Beyond Mortality?

    Directory of Open Access Journals (Sweden)

    Charles Sheppard

    2000-01-01

    Full Text Available The scale of the collapse of coral reef communities in 1998 following a warming episode (Wilkinson, 2000 was unprecedented, and took many people by surprise. The Indian Ocean was the worst affected with a coral mortality over 75% in many areas such as the Chagos Archipelago (Sheppard, 1999, Seychelles (Spencer et al., 2000 and Maldives (McClanahan, 2000. Several other locations were affected at least as much, with mortality reaching 100% (to the nearest whole number; this is being compiled by various authors (e.g., CORDIO, in press. For example, in the Arabian Gulf, coral mortality is almost total across many large areas of shallow water (Sheppard, unpublished; D. George and D. John, personal communication. The mortality is patchy of course, depending on currents, location inside or outside lagoons, etc., but it is now possible to swim for over 200 m and see not one remaining living coral or soft coral on some previously rich reefs.

  18. 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.

  19. Habitat preference of Zoantharia genera depends on host sponge morphology

    Directory of Open Access Journals (Sweden)

    Alberto Acosta

    2010-08-01

    Full Text Available Studies about sponge-zoanthid symbioses have been focused on understanding the specificity of the association, rather thantesting what are the characteristics that make the host suitable to be colonized. For the first time it is investigated whether the ZoanthariaParazoanthus and Epizoanthus preference is related to the host sponge morphology (shape and mechanical resistance. Materials andmethods. Sponges were categorized according to their shape and mechanical resistance. The presence/absence of zoanthids was recordedin 1,068 sponges at San Andres Island, and their habitat preference was evaluated using indices and confidence intervals. Results. 85Parazoanthus colonies (78% of the total associations and 24 Epizoanthus colonies (22% were associated to sponges (10.2% in total.Parazoanthus uses branched and compressible sponges although prefers encrusting and fragile sponges, while Epizoanthus showes theopposite pattern, it can inhabit encrusting and fragile sponges but prefers branched and compressible sponges. Conclusion. These resultsindicated that sponge morphology is an important trait in zoanthid habitat selection. On the other hand, the similarity in the habitat used byzoanthids suggests the possibility of inter-generic competition if common resources are limited in time and space, while the differentialhabitat preference allows the competitive coexistence of both genera.

  20. [Trophic webs of reef fishes in northwestern Cuba. I. Stomach contents].

    Science.gov (United States)

    Hernández, Ivet; Aguilar, Consuelo; González Sanón, Gaspar

    2008-06-01

    Trophic webs of reef fishes in northwestern Cuba. I. Stomach contents. Studies on the reef fishes of Cuba are not rare, but most have two basic limitations: small sample sizes and exclusion of small species. Our study sampled more species and larger samples in the sublitoral region of Havana city (23 degrees 7.587' N, 82 degrees 25.793' W), 2-18 m deep. We collected fish weekly from October 2004 through February 2006 with traps and harpoon. Overfishing has modified the fish communities. We used the relative importance index to describe the diets of carnivore and omnivore species, and a modification of the relative abundance method for the herbivores and sponge-eating species. The main food items are benthonic crustaceans (crabs, shrimp, copepods) and bony fish (mainly demersal species). Most species are eurifagous and thus, less affected by anthropic disturbance than specialist feeders.

  1. Subsurface example of a dolomitized middle Guadalupian (Permian) reef from west Texas

    Energy Technology Data Exchange (ETDEWEB)

    Longacre, S.A.

    1983-01-01

    A middle Guadalupian organic buildup was cored in the North McElroy Unit (NMU No. 3713 well) in Upton County, W. Texas. Fusulinid control indicates the buildup is equivalent to the Goat Seep reef that crops out in the Guadalupe Mt. The organic buildup at North McElroy consists of boundstones and associated flank grainstones. The reef biota is dominated by ramose and encrusting bryozoans, numerous types of calcareous sponges, the problematic encrusting organism Tubiphytes, encrusting algae, crinoids, brachiopods, and trilobites. Among the more significant aspects of diagenesis are mechanical degradation and biologic degradation, leaching, gypsum-anhydrite transformations, cementation, replacement of all calcite by dolomite, cementation and replacement by baroque dolomite, fracturing, and replacement of carbonate by anhydrite. 17 references.

  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. Ultraporous, Compressible, Wettable Polylactide/Polycaprolactone Sponges for Tissue Engineering.

    Science.gov (United States)

    Mader, Michael; Jérôme, Valérie; Freitag, Ruth; Agarwal, Seema; Greiner, Andreas

    2018-05-14

    Ultraporous, degradable sponges made of either polylactide or of blends of polylactide/poly(ε-caprolactone) are prepared by freeze-drying of dispersions of short electrospun fibers and subsequent thermal annealing. The sponges feature ultrahigh porosity (99.6%), a hierarchical cellular structure, and high reversible compressibility with fast recovery from deformation in the dry as well as in the wet state. The sponge properties depend on the fiber dispersion concentration and the annealing temperature. Sponge characteristics like fiber density (2.5-20 mg/cm 3 ), size, shape, crystallinity, mechanical strength, wetability, and structural integrity are user adjustable. Cell culture experiments were successfully performed with Jurkat cells with Confocal Laser Scanning Microscopy and MTT staining showing rapid cell proliferation. Live/Dead staining demonstrated high viability of the seeded cells. The sponge characteristics and modifications investigated and presented here reveal that these sponges are highly promising for tissue engineering applications.

  4. 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.

  5. New records of Cotylea (Polycladida, Platyhelminthes) from Lizard Island, Great Barrier Reef, Australia, with remarks on the distribution of the Pseudoceros Lang, 1884 and Pseudobiceros Faubel, 1984 species of the Indo-Pacific Marine Region.

    Science.gov (United States)

    Marquina, Daniel; Aguado, M Teresa; Noreña, Carolina

    2015-09-18

    In the present work eleven polyclad species of Lizard Island are studied. Seven of them are new records for this locality of the Australian coral reef and one is new to science, Lurymare clavocapitata n. sp. (Family Prosthiostomidae). The remaining recorded species belong to the genera Pseudoceros (P. bimarginatus, P. jebborum, P. stimpsoni, P. zebra, P. paralaticlavus and P. prudhoei) and Pseudobiceros (Pb. hancockanus, Pb. hymanae, Pb. flowersi and Pb. uniarborensis). Regardless of the different distribution patterns, all pseudocerotid species show brilliant colours, but similar internal morphology. Furthermore, differences in the form and size of the stylet are characteristic, because it is a sclerotic structure that is not affected during fixation. In Pseudoceros, the distance between the sucker and the female pore also differs among species. These features do not vary enough to be considered as diagnostic, but they provide information that can help to disentangle similarly coloured species complexes. A key of the genera Pseudoceros and Pseudobiceros of the Indo-Pacific region is provided, in order to facilitate the identification of species from this area.

  6. State of the coralline reefs

    International Nuclear Information System (INIS)

    Garzon Ferreira, Jaime; Rodriguez Ramirez, Alberto; Bejarano Chavarro, Sonia; Navas Camacho, Raul; Reyes Nivia, Catalina

    2002-01-01

    A diagnosis is made based primarily on the data obtained inside the national system of monitoring of coralline reefs in Colombia, under the coordination of the INVEMAR and with the support of several institutions. The paper does a diagnostic of the covering of the reef substrate, bleaching and coralline illnesses, wealth and abundance of fishes among other topics

  7. Human activities threaten coral reefs

    International Nuclear Information System (INIS)

    Tveitdal, Svein; Bjoerke, Aake

    2002-01-01

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

  8. How complementary are epibenthic assemblages in artificial and nearby natural rocky reefs?

    KAUST Repository

    Carvalho, Susana

    2013-12-01

    The present study analyses the composition, structure and trophic function of epibenthic assemblages in two artificial reefs (ARs) 16 years after deployment and in nearby natural reefs (NRs), aiming at providing insights on the complementarity between both habitats. Current findings suggest that after 16 years the ARs (concrete blocks), located in southern Portugal, do not act as surrogates for NRs, as epibenthic assemblages differed between reef types in composition, structure and trophic function. NRs showed higher diversity and complementarity (i.e. beta-diversity) than ARs, evidencing higher redundancy. Higher heterogeneity within NRs was also evidenced by the multi-dimensional scaling analysis based on abundance, biomass and trophic composition. NRs presented higher abundance of molluscs and biomass of sponges, resulting in differences in the trophic function: suspension-feeding dominated the NRs, while within ARs there was an ascendency of carnivory. Although not acting as surrogates for NRs and provided that no adverse effects (e.g. establishment of non-native species) were detected, ARs may have a significant contribution for the increase of regional diversity, as evidenced by the highest complementarity levels observed between assemblages in both reefs. © 2013 Elsevier Ltd.

  9. How complementary are epibenthic assemblages in artificial and nearby natural rocky reefs?

    KAUST Repository

    Carvalho, Susana; Moura, Ana; Cú rdia, Joã o; Cancela da Fonseca, Luí s; Santos, Miguel N.

    2013-01-01

    The present study analyses the composition, structure and trophic function of epibenthic assemblages in two artificial reefs (ARs) 16 years after deployment and in nearby natural reefs (NRs), aiming at providing insights on the complementarity between both habitats. Current findings suggest that after 16 years the ARs (concrete blocks), located in southern Portugal, do not act as surrogates for NRs, as epibenthic assemblages differed between reef types in composition, structure and trophic function. NRs showed higher diversity and complementarity (i.e. beta-diversity) than ARs, evidencing higher redundancy. Higher heterogeneity within NRs was also evidenced by the multi-dimensional scaling analysis based on abundance, biomass and trophic composition. NRs presented higher abundance of molluscs and biomass of sponges, resulting in differences in the trophic function: suspension-feeding dominated the NRs, while within ARs there was an ascendency of carnivory. Although not acting as surrogates for NRs and provided that no adverse effects (e.g. establishment of non-native species) were detected, ARs may have a significant contribution for the increase of regional diversity, as evidenced by the highest complementarity levels observed between assemblages in both reefs. © 2013 Elsevier Ltd.

  10. Climatic and tectonic controls on late Quaternary reef growth in New Caledonia

    International Nuclear Information System (INIS)

    Cabioch, G.; Recy, J.; Jouannic, CH.; Turpin, L.

    1996-01-01

    Sedimentological and stratigraphic analysis of about 40 sub-surface cores drilled through the reefs of New Caledonia provides valuable data on the processes of reef recolonization following the past post glacial sea-level rise, and on the vertical tectonic behaviour of the island over the past 125,000 years. Holocene reefs in New Caledonia are not older than 8.5 ky. The fringing reef which developed during the last interglacial high sea-level 125 ky ago, is today uplifted and lies along some 30 km of coast in the area of 10 m, while the present-day barrier reef is deeply submerged (around - 15 to - 20 m). Near Hienghene (east coast), a double system of two notches is markedly deformed by a bulge, but is much more localized (3 km long) than in the Yate area, with a maximum uplift of 13 m of the upper double notch system (interpreted as having formed during the last interglacial event). Relics of the 125 ky fringing reef are emergent at various locations in the Bourail region (west coast). However, their altitudes are lower than that generally admitted (+ 6 m) for their construction at 125 ky, thus most probably reflecting a slight subsidence of the area. Elsewhere, the 125 ky fringing reef underlies the Holocene reef: in the SW of the island, in particular, the Holocene - Pleistocene unconformity is observed at - 6 m. In areas of higher subsidence rates, such as the NW or NE of the island, the 125 ky fringing reef may be more deeply buried. In that case, the Holocene reef rests directly on a metamorphic or sedimentary substratum. Within the barrier reef build-up itself, the 125 ky reef flat is overlain by a Holocene sequence, whose thickness depends on local subsidence rates. The observation of notches, raised becah-rocks or coral reefs (dated ar around 5,500 yr) uplifted up to 1 to 1,5 m above MLWS reflects the existence of a hydro-isostatic rebound. Traces of this rebound disappear in areas of high subsidence rate, illustrating the action of local tectonics

  11. Bacteria From Marine Sponges: A Source of New Drugs.

    Science.gov (United States)

    Bibi, Fehmida; Faheem, Muhammad; Azhar, Esam I; Yasir, Muhammad; Alvi, Sana A; Kamal, Mohammad A; Ullah, Ikram; Naseer, Muhammad I

    2017-01-01

    Sponges are rich source of bioactive natural products synthesized by the symbiotic bacteria belonging to different phyla. Due to a competition for space and nutrients the marine bacteria associated with sponges could produce more antibiotic substances. To explore the proactive potential of marine microbes extensive research has been done. These bioactive metabolites have some unique properties that are pharmaceutically important. For this review, we have performed a non-systematic search of the available literature though various online search engines. This review provides an insight that how majority of active metabolites have been identified from marine invertebrates of which sponges predominate. Sponges harbor abundant and diverse microorganisms, which are the sources of a range of marine bioactive metabolites. From sponges and their associated microorganisms, approximately 5,300 different natural compounds are known. Current research on sponge-microbe interaction and their active metabolites has become a focal point for many researchers. Various active metabolites derived from sponges are now known to be produced by their symbiotic microflora. In this review, we attempt to report the latest studies regarding capability of bacteria from sponges as producers of bioactive metabolite. Moreover, these sponge associated bacteria are an important source of different enzymes of industrial significance. In present review, we will address some novel approaches for discovering marine metabolites from bacteria that have the greatest potential to be used in clinical treatments. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. 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...

  13. Two Furanosesterterpenoids from the Sponge Luffariella variabilis

    Directory of Open Access Journals (Sweden)

    Peni Ahmadi

    2017-08-01

    Full Text Available Two new sesterterpenoids, 1 and 2, were isolated from the sponge Luffariella variabilis. Their planar structures were characterized with spectroscopic analyses. The sole chiral center of compound 1 was elucidated as 12R by comparing observed and calculated optical rotation values. The configurations of compound 2 were determined by NMR and electronic circular dichroism (ECD studies. Furthermore, compound 2 showed cytotoxicity at IC50 1.0 µM against NBT-T2 cells.

  14. Snapshot recordings provide a first description of the acoustic signatures of deeper habitats adjacent to coral reefs of Moorea

    Directory of Open Access Journals (Sweden)

    Frédéric Bertucci

    2017-11-01

    Full Text Available Acoustic recording has been recognized as a valuable tool for non-intrusive monitoring of the marine environment, complementing traditional visual surveys. Acoustic surveys conducted on coral ecosystems have so far been restricted to barrier reefs and to shallow depths (10–30 m. Since they may provide refuge for coral reef organisms, the monitoring of outer reef slopes and describing of the soundscapes of deeper environment could provide insights into the characteristics of different biotopes of coral ecosystems. In this study, the acoustic features of four different habitats, with different topographies and substrates, located at different depths from 10 to 100 m, were recorded during day-time on the outer reef slope of the north Coast of Moorea Island (French Polynesia. Barrier reefs appeared to be the noisiest habitats whereas the average sound levels at other habitats decreased with their distance from the reef and with increasing depth. However, sound levels were higher than expected by propagation models, supporting that these habitats possess their own sound sources. While reef sounds are known to attract marine larvae, sounds from deeper habitats may then also have a non-negligible attractive potential, coming into play before the reef itself.

  15. Coal ash artificial reef demonstration

    International Nuclear Information System (INIS)

    Livingston, R.J.; Brendel, G.F.; Bruzek, D.A.

    1991-01-01

    This experimental project evaluated the use of coal ash to construct artificial reefs. An artificial reef consisting of approximately 33 tons of cement-stabilized coal ash blocks was constructed in approximately 20 feet of water in the Gulf of Mexico approximately 9.3 miles west of Cedar Key, Florida. The project objectives were: (1) demonstrate that a durable coal ash/cement block can be manufactured by commercial block-making machines for use in artificial reefs, and (2) evaluate the possibility that a physically stable and environmentally acceptable coal ash/cement block reef can be constructed as a means of expanding recreational and commercial fisheries. The reef was constructed in February 1988 and biological surveys were made at monthly intervals from May 1988 to April 1989. The project provided information regarding: Development of an optimum design mix, block production and reef construction, chemical composition of block leachate, biological colonization of the reef, potential concentration of metals in the food web associated with the reef, acute bioassays (96-hour LC 50 ). The Cedar Key reef was found to be a habitat that was associated with a relatively rich assemblage of plants and animals. The reef did not appear to be a major source of heavy metals to species at various levels of biological organization. GAI Consultants, Inc (GAI) of Monroeville, Pennsylvania was the prime consultant for the project. The biological monitoring surveys and evaluations were performed by Environmental Planning and Analysis, Inc. of Tallahassee, Florida. The chemical analyses of biological organisms and bioassay elutriates were performed by Savannah Laboratories of Tallahassee, Florida. Florida Power Corporation of St. Petersburg, Florida sponsored the project and supplied ash from their Crystal River Energy Complex

  16. Iron sponge installation clicks at Retlaw plant

    Energy Technology Data Exchange (ETDEWEB)

    1965-06-21

    Iron sponge desulfurization, often ignored by plant designers in favor of the monoethanolamine process, may offer economic advantages in sweetening of small gas volumes with low hydrogen sulfide and carbon dioxide content. The process removes hydrogen sulfide and mercaptans by passing sour gas through vessels loosely packed with wood shavings impregnated by a hydrated form of iron oxide, which reacts with the hydrogen sulfide to form ferric sulfide. The disadvantages are that carbon dioxide is not removed, hydrate formation is a danger in cold weather, and gas sales may be lost when towers are down for servicing. Periodic regeneration of beds takes about a day, and sponges must be replaced occasionally. Despite these shortcomings, the process may prove economical, since a typical plant costs $110,000 as compared to $270,000 for an amine unit. The expense of operating the plant is $23,000 compared with $28,000 for the amine unit. Thus, economics clearly favor the iron sponge process.

  17. Optimization of biodegradable sponges as controlled release drug matrices. I. Effect of moisture level on chitosan sponge mechanical properties.

    Science.gov (United States)

    Foda, Nagwa H; El-laithy, Hanan M; Tadros, Mina I

    2004-04-01

    Cross-linked chitosan sponges as controlled release drug carrier systems were developed. Tramadol hydrochloride, a centrally acting analgesic, was used as a model drug. The sponges were prepared by freeze-drying 1.25% and 2.5% (w/w) high and low M.wt. chitosan solutions, respectively, using glutaraldehyde as a cross-linking agent. The hardness of the prepared sponges was a function of glutaraldehyde concentration and volume where the optimum concentration that offered accepted sponge consistency was 5%. Below or above 5%, very soft or very hard and brittle sponges were obtained, respectively. The determined drug content in the prepared sponges was uniform and did not deviate markedly from the calculated amount. Scanning electron microscopy (SEM) was used to characterize the internal structures of the sponges. The SEM photos revealed that cross-linked high M.wt. chitosan sponges have larger size surface pores that form connections (channels) with the interior of the sponge than cross-linked low M.wt. ones. Moreover, crystals of the incorporated Tramadol hydrochloride were detected on the lamellae and within pores in both chitosan sponges. Differences in pore size and dissolution medium uptake capacity were crucial factors for the more delayed drug release from cross-linked low M.wt. chitosan sponges over high M.wt. ones at pH 7.4. Kinetic analysis of the release data using linear regression followed the Higuchi diffusion model over 12 hours. Setting storage conditions at room temperature under 80-92% relative humidity resulted in soft, elastic, and compressible sponges.

  18. 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.

  19. 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...

  20. Mesopredator trophodynamics on thermally stressed coral reefs

    Science.gov (United States)

    Hempson, Tessa N.; Graham, Nicholas A. J.; MacNeil, M. Aaron; Hoey, Andrew S.; Almany, Glenn R.

    2018-03-01

    Ecosystems are becoming vastly modified through disturbance. In coral reef ecosystems, the differential susceptibility of coral taxa to climate-driven bleaching is predicted to shift coral assemblages towards reefs with an increased relative abundance of taxa with high thermal tolerance. Many thermally tolerant coral species are characterised by low structural complexity, with reduced habitat niche space for the small-bodied coral reef fishes on which piscivorous mesopredators feed. This study used a patch reef array to investigate the potential impacts of climate-driven shifts in coral assemblages on the trophodynamics of reef mesopredators and their prey communities. The `tolerant' reef treatment consisted only of coral taxa of low susceptibility to bleaching, while `vulnerable' reefs included species of moderate to high thermal vulnerability. `Vulnerable' reefs had higher structural complexity, and the fish assemblages that established on these reefs over 18 months had higher species diversity, abundance and biomass than those on `tolerant' reefs. Fish assemblages on `tolerant' reefs were also more strongly influenced by the introduction of a mesopredator ( Cephalopholis boenak). Mesopredators on `tolerant' reefs had lower lipid content in their muscle tissue by the end of the 6-week experiment. Such sublethal energetic costs can compromise growth, fecundity, and survivorship, resulting in unexpected population declines in long-lived mesopredators. This study provides valuable insight into the altered trophodynamics of future coral reef ecosystems, highlighting the potentially increased vulnerability of reef fish assemblages to predation as reef structure declines, and the cost of changing prey availability on mesopredator condition.

  1. Global microbialization of coral reefs.

    Science.gov (United States)

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

    2016-04-25

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

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

    KAUST Repository

    Wild, Christian

    2014-09-16

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

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

    Science.gov (United States)

    Wild, Christian; Jantzen, Carin; Kremb, Stephan Georg

    2014-01-01

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

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

    KAUST Repository

    Wild, Christian; Jantzen, Carin; Kremb, Stephan Georg

    2014-01-01

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

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

    Science.gov (United States)

    Diedrich, A.

    2007-12-01

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

  6. DYNAPHORE, INC. FORAGER™ SPONGE TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    The Forager™ Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that selectively absorbs dissolved heavy metals from aqueous waste streams. The Developer states that the technology can be utilized to remove and concentrate heavy metals f...

  7. The dimension of the pore space in sponges

    International Nuclear Information System (INIS)

    Silva, L H F; Yamashita, M T

    2009-01-01

    A simple experiment to reveal the dimension of the pore space in sponges is proposed. This experiment is suitable for the first year of a physics or engineering course. The calculated dimension of the void space in a sponge of density 16 mg cm -3 was 2.948± 0.008

  8. Keratin sponge/hydrogel part 1. fabrication and characterization

    Science.gov (United States)

    Keratin sponge/hydrogel products formed by either the oxidation or reduction of U.S. domestic fine- or coarse-grade wool exhibited distinctively different topologies and molecular weights of 6- 8 kDa and 40-60 kDa, each with unique macro-porous structure and microstructural behaviors. The sponge/ ...

  9. Post-quantum security of the sponge construction

    NARCIS (Netherlands)

    Czajkowski, J.; Groot Bruinderink, L.; Hülsing, A.T.; Schaffner, C.; Unruh, D.

    2017-01-01

    We investigate the post-quantum security of hash functions based on the sponge construction. A crucial property for hash functions in the post-quantum setting is the collapsing property (a strengthening of collision-resistance). We show that the sponge construction is collapsing (and in consequence

  10. Post-quantum security of the sponge construction

    NARCIS (Netherlands)

    Czajkowski, Jan; Groot Bruinderink, Leon; Hülsing, Andreas; Schaffner, Christian; Unruh, Dominique

    2018-01-01

    We investigate the post-quantum security of hash functions based on the sponge construction. A crucial property for hash functions in the post-quantum setting is the collapsing property (a strengthening of collision-resistance). We show that the sponge construction is collapsing (and in consequence

  11. Deep-sea sponge grounds: Reservoirs of biodiversity

    NARCIS (Netherlands)

    Hogg, M.M.; Tendal, O.S.; Conway, K.W.; Pomponi, S.A.; van Soest, R.W.M.; Gutt, J.; Krautter, M.; Roberts, J.M.

    2010-01-01

    This report draws together scientific understanding of deep-water sponge grounds alongside the threats they face and ways in which they can be conserved. Beginning with a summary of research approaches, sponge biology and biodiversity, the report also gives up-to-date case studies of particular

  12. Stimulatory activity of four green freshwater sponges on aquatic ...

    African Journals Online (AJOL)

    The effect of green sponges on the abundance of aquatic mycotal species is caused by dissolved organic matter produced during photosynthesis by symbiotic zoochlorellae, a symbionts of green sponges and excreted into the water environment (S. fluviatilis excreted mean 12.8% of carbon fixation). Those excreted organic ...

  13. Mangrove-sponge associations: a possible role for tannins

    NARCIS (Netherlands)

    Hunting, E.R.; van der Geest, H.G.; Krieg, A.J.; van Mierlo, M.B.L.; van Soest, R.W.M.

    2010-01-01

    A positive correlation between sponge coverage and tannin concentrations in prop roots of Rhizophora mangle L. has previously been reported. However, the ecological role of tannins within the mangrove sponge association remains speculative. This study investigated whether tannins play a role in

  14. Cultivation of sponge larvae: settlement, survival, and growth of juveniles

    NARCIS (Netherlands)

    Caralt, de S.; Otjens, H.; Uriz, M.J.; Wijffels, R.H.

    2007-01-01

    The aim of this study was to culture sponge juveniles from larvae. Starting from larvae we expected to enhance the survival and growth, and to decrease the variation in these parameters during the sponge cultures. First, settlement success, morphological changes during metamorphosis, and survival of

  15. Bioprospecting sponge-associated microbes for antimicrobial compounds

    NARCIS (Netherlands)

    Indraningrat, Anak Agung Gede; Smidt, Hauke; Sipkema, Detmer

    2016-01-01

    Sponges are the most prolific marine organisms with respect to their arsenal of bioactive compounds including antimicrobials. However, the majority of these substances are probably not produced by the sponge itself, but rather by bacteria or fungi that are associated with their host. This review

  16. Ecological interactions and the distribution, abundance, and diversity of sponges.

    Science.gov (United States)

    Wulff, Janie

    2012-01-01

    Although abiotic factors may be important first-order filters dictating which sponge species can thrive at a particular site, ecological interactions can play substantial roles influencing distribution and abundance, and thus diversity. Ecological interactions can modify the influences of abiotic factors both by further constraining distribution and abundance due to competitive or predatory interactions and by expanding habitat distribution or abundance due to beneficial interactions that ameliorate otherwise limiting circumstances. It is likely that the importance of ecological interactions has been greatly underestimated because they tend to only be revealed by experiments and time-series observations in the field. Experiments have revealed opportunistic predation to be a primary enforcer of sponge distribution boundaries that coincide with habitat boundaries in several systems. Within habitats, by contrast, dramatic effects of predators on sponge populations seem to occur primarily in cases of unusually high recruitment rates or unusually low mortality rates for the predators, which are often specialists on the sponge species affected. Competitive interactions have been demonstrated to diminish populations or exclude sponge species from a habitat in only a few cases. Cases in which competitive interactions have appeared obvious have often turned out to be neutral or even beneficial interactions when observed over time. Especially striking in this regard are sponge-sponge interactions in dense sponge-dominated communities, which may promote the continued coexistence of all participating species. Mutualistic symbioses of sponges with other animals, plants, or macroalgae have been demonstrated to increase abundance, habitat distribution, and diversity of all participants. Symbiotic microbes can enhance sponge distribution and abundance but also render their hosts more vulnerable to environmental changes. And while photosynthetic symbionts can boost growth and

  17. Oxygen dynamics and transport in the Mediterranean sponge Aplysina aerophoba

    DEFF Research Database (Denmark)

    Hoffmann, F.; Røy, Hans; Bayer, K.

    2008-01-01

    The Mediterranean sponge Aplysina aerophoba kept in aquaria or cultivation tanks can stop pumping for several hours or even days. To investigate changes in the chemical microenvironments, we measured oxygen profiles over the surface and into the tissue of pumping and non-pumping A. aerophoba...... specimens with Clark-type oxygen microelectrodes (tip diameters 18-30 μm). Total oxygen consumption rates of whole sponges were measured in closed chambers. These rates were used to back-calculate the oxygen distribution in a finite-element model. Combining direct measurements with calculations of diffusive...... flux and modeling revealed that the tissue of non-pumping sponges turns anoxic within 15 min, with the exception of a 1 mm surface layer where oxygen intrudes due to molecular diffusion over the sponge surface. Molecular diffusion is the only transport mechanism for oxygen into non-pumping sponges...

  18. 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.

  19. Distribution of Georgia Oyster Reefs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The feature class in this ESRI Geodatabase contains polygons representing oyster reefs along the Georgia coastal waterways from Chatham County south to Glynn County....

  20. Tortugas Reef Fish Census (CRCP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is a long term data set collecting visual census transect data on reef fishes at staions located at Rileys Hump, Tortugas South Ecological Reservee.

  1. 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...

  2. Coral Reef Protection Implementation Plan

    National Research Council Canada - National Science Library

    Lobel, Lisa

    2000-01-01

    This document identify policies and actions to implement the Department of Defense's responsibilities under Executive Order 13089 on Coral Reef Protection, and are a requirement of the interim Task...

  3. Recovery of the commercial sponges in the central and southeastern Aegean Sea (NE Mediterranean after an outbreak of sponge disease

    Directory of Open Access Journals (Sweden)

    J. CASTRITSI-CATHARIOS

    2011-01-01

    Full Text Available The distribution and biometry of commercial sponges (Porifera in coastal areas of the central and southeastern Aegean Sea was investigated to estimate the recovery progress of the populations eight years after the first appearance of sponge disease. Signs of the disease were detected only in 1.6% of the harvested sponges. Multivariate analysis on the percentage abundance of sponges showed two distinct groups among the sixteen fishing grounds studied: the eight deep (50-110 m and the eight shallow ones (<40 m. The group from the deep depths consisted of Spongia officinalis adriatica, S. agaricina and S. zimocca. The infralittoral zone was characterized by the presence of Hippospongia communis, S. officinalis adriatica and S. officinalis mollissima. These bath sponges showed an enhanced abundance in the eastern Cretan Sea (S. Aegean Sea. In addition, their dimensions, particularly height, increased with increasing depth. It is indicated that the hydrographic conditions prevailing in the eastern Cretan Sea affected the repopulating processes of sponge banks. In each species, the biometric characteristics of the experimental specimens were similar to those of the sponges found in the market and harvested at respective depths prior to the appearance of sponge disease.

  4. The sponge pump: the role of current induced flow in the design of the sponge body plan.

    Directory of Open Access Journals (Sweden)

    Sally P Leys

    Full Text Available Sponges are suspension feeders that use flagellated collar-cells (choanocytes to actively filter a volume of water equivalent to many times their body volume each hour. Flow through sponges is thought to be enhanced by ambient current, which induces a pressure gradient across the sponge wall, but the underlying mechanism is still unknown. Studies of sponge filtration have estimated the energetic cost of pumping to be 0.75 with the ambient current velocity. During short bursts of high ambient current the sponges filtered two-thirds of the total volume of water they processed daily. Our model indicates that the head loss across the sponge collar filter is 10 times higher than previously estimated. The difference is due to the resistance created by a fine protein mesh that lines the collar, which demosponges also have, but was so far overlooked. Applying our model to the in situ measurements indicates that even modest pumping rates require an energetic expenditure of at least 28% of the total in situ respiration. We suggest that due to the high cost of pumping, current-induced flow is highly beneficial but may occur only in thin walled sponges living in high flow environments. Our results call for a new look at the mechanisms underlying current-induced flow and for reevaluation of the cost of biological pumping and its evolutionary role, especially in sponges.

  5. 21 CFR 529.1003 - Flurogestone acetate-impregnated vaginal sponge.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Flurogestone acetate-impregnated vaginal sponge... § 529.1003 Flurogestone acetate-impregnated vaginal sponge. (a) Specifications. Each vaginal sponge... ewes during their normal breeding season. (2) Limitations. Using applicator provided, insert sponge...

  6. 21 CFR 878.4014 - Nonresorbable gauze/sponge for external use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonresorbable gauze/sponge for external use. 878... Nonresorbable gauze/sponge for external use. (a) Identification. A nonresorbable gauze/sponge for external use... include a nonresorbable gauze/sponge for external use that contains added drugs such as antimicrobial...

  7. Coral reef bleaching: ecological perspectives

    Science.gov (United States)

    Glynn, P. W.

    1993-03-01

    Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt

  8. SPONGE ROBOTIC HAND DESIGN FOR PROSTHESES

    OpenAIRE

    Mine Seçkin

    2016-01-01

    In this study robotic hands and fingers’ materials are investigated from past to present and a sponge robotic hand is designed for biomedical applications. Emergence and necessity of soft robotic technology are explained and description of soft robot is made. Because of the importance of hand in a person’s body, researchers have dealt with robotic hand prostheses for many centuries and developed many hand types. To mimic the best for the human limbs, softness of the hand is one of the importa...

  9. The coral reef of South Moloka'i, Hawai'i - Portrait of a sediment-threatened fringing reef

    Science.gov (United States)

    Field, Michael E.; Cochran, Susan A.; Logan, Joshua; Storlazzi, Curt D.

    2008-01-01

    Moloka‘i, with the most extensive coral reef in the main Hawaiian Islands, is especially sacred to Hina, the Goddess of the Moon. As Hinaalo, she is the Mother of the Hawaiian people; as Hinapuku‘a, she is the Goddess of Fishermen; and in the form Hina‘opuhalako‘a, she is the Goddess who gave birth to coral, coral reefs, and all spiny marine organisms. Interdependence between the reef’s living resources, the people, and their cosmology was the basis for management of Moloka‘i’s coastal waters for over a thousand years.The ancient residents of Moloka‘i built the greatest concentration of fishponds known anywhere, but their mastery of mariculture, something needed now more than ever, was lost after near genocide from exotic Western diseases. Subsequent destruction of the native vegetation for exotic cattle, goats, pigs, sugar cane, and pineapple caused soil erosion and sedimentation on the reef flat. This masterful volume clearly documents that soil washing into the sea is the major threat to the reef today. Abandoned fishponds, choked with sediment, now act as barriers and mud traps, making damage to corals less than it would otherwise would have been.The role of mud and freshwater from land in preventing coral reef growth, clearly articulated in Charles Darwin’s first book, The Structure and Distribution of Coral Reefs, is the major theme of this book. All around the tropics, coral reefs have died from huge increases in terrestrial sedimentation that resulted from destruction of hillside forests for cash-crop agriculture and pastures in the colonial era, especially in Latin America, Asia, and the islands of the Caribbean and Indo-Pacific. It is obvious that one cannot manage the coastal zone as a unit separate from the watersheds that drain into it. Yet there has been surprisingly little comprehensive scientific study of these impacts.In this landmark volume, U.S. Geological Survey researchers and their colleagues have developed and applied a

  10. Subsurface Permian reef complexes of southern Tunisia: Shelf carbonate setting and paleogeographic implications

    Science.gov (United States)

    Zaafouri, Adel; Haddad, Sofiene; Mannaî-Tayech, Beya

    2017-05-01

    2-D seismic reflection sections, borehole data as well as published and unpublished data have been investigated to reconstruct the paleogeography of southern Tunisia during Middle to Late Permian times. Paleogeographical reconstruction based on the integration of petroleum well data and 2-D seismic facies interpretation shows three main depositional areas with very contrasting sedimentary pile. These are 1) a subsiding basin; 2) an outer shelf carbonate, and 3) an inner shelf carbonate. Based on typical electric responses of reef buildups to seismic wave, we shall urge that during Middle Permian times, the outer carbonate shelf was subject of reef barrier development. Lithology evidences from core samples show that reef framework correspond mainly to fossiliferous limestone and dolomite. The WNW-ESE recognized reef barrier led between latitudes 33° 10‧ 00″N and 33° 20‧ 00″N. The Tebaga of Medenine outcrop constitutes the northern-edge of this barrier. Westward it may be extended to Bir Soltane area whereas its extension eastward is still to be determined. Biogenic buildups took place preferentially over faulted Carboniferous and lower Paleozoic paleohighs resulting likely from the Hercynian orogeny. The subsiding basin is located north of Tebaga of Medenine outcrop where Upper Permian sedimentary sequence is made entirely of 4000 m deep marine green silty shale facies. These are ascribed to unorganized and chaotic reflectors. Inner carbonate shelf facies succession corresponds to a typical interbedding of shallow marine carbonate deposits, shale, dolomite, and anhydrite inducing parallel-layered of strong amplitude and good continuity reflectors. Also within the inner carbonate shelf patch reef or reef pinnacles have been identified based on their seismic signature particularly their low vertical development as compared to reef complexes. Southward, towards Sidi Toui area, the Upper Permian depositional sequence thins out and bears witness of land

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

    Directory of Open Access Journals (Sweden)

    Guillermo Diaz-Pulido

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

  12. National Coral Reef Monitoring Program: Coral Reef Fish collected in Fl Keys Reef Tract (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Divers conducted reef visual census (RVC) fish surveys and habitat assessments at 433 sites in the Florida Keys, 436 sites in the Dry Tortugas and 320 sites in the...

  13. Effect of Melamine Sponge on Tooth Stain Removal.

    Science.gov (United States)

    Otsuka, Takero; Kawata, Toshitsugu

    2015-01-01

    To investigate the stain removal ability of melamine sponge before aesthetic tooth whitening in extracted teeth. Melamine sponge of thickness 40 mm was compressed and the destruction of the partition wall structure during the compression process was examined under a stereoscopic microscope. An extracted human tooth was cleaned by normal polishing or with melamine sponge for 90 s. To evaluate the stain level, the tooth surfaces were photographed under a stereoscopic microscope at 0, 30, 60 and 90 s. The residual stained region was traced in a high-magnification photograph, and the stain intensity was presented as a change, relative to the intensity before the experiment (0 s). Mechanical cleaning by toothbrushing produced polishing scratches on the tooth surface, whereas use of the melamine sponge resulted in only minimal scratches. As the compression level increased, the stain-removing effect tended to become stronger. Melamine sponge can remove stains from the tooth surface more effectively and less invasively compared to a conventional toothbrush. As no new scratches are made on the tooth surface when using a melamine sponge brush, the risk of re-staining is reduced. Cleaning using a melamine sponge brush can be easily and effectively performed at home and in a dental office.

  14. Bioprospecting Sponge-Associated Microbes for Antimicrobial Compounds.

    Science.gov (United States)

    Indraningrat, Anak Agung Gede; Smidt, Hauke; Sipkema, Detmer

    2016-05-02

    Sponges are the most prolific marine organisms with respect to their arsenal of bioactive compounds including antimicrobials. However, the majority of these substances are probably not produced by the sponge itself, but rather by bacteria or fungi that are associated with their host. This review for the first time provides a comprehensive overview of antimicrobial compounds that are known to be produced by sponge-associated microbes. We discuss the current state-of-the-art by grouping the bioactive compounds produced by sponge-associated microorganisms in four categories: antiviral, antibacterial, antifungal and antiprotozoal compounds. Based on in vitro activity tests, identified targets of potent antimicrobial substances derived from sponge-associated microbes include: human immunodeficiency virus 1 (HIV-1) (2-undecyl-4-quinolone, sorbicillactone A and chartarutine B); influenza A (H1N1) virus (truncateol M); nosocomial Gram positive bacteria (thiopeptide YM-266183, YM-266184, mayamycin and kocurin); Escherichia coli (sydonic acid), Chlamydia trachomatis (naphthacene glycoside SF2446A2); Plasmodium spp. (manzamine A and quinolone 1); Leishmania donovani (manzamine A and valinomycin); Trypanosoma brucei (valinomycin and staurosporine); Candida albicans and dermatophytic fungi (saadamycin, 5,7-dimethoxy-4-p-methoxylphenylcoumarin and YM-202204). Thirty-five bacterial and 12 fungal genera associated with sponges that produce antimicrobials were identified, with Streptomyces, Pseudovibrio, Bacillus, Aspergillus and Penicillium as the prominent producers of antimicrobial compounds. Furthemore culture-independent approaches to more comprehensively exploit the genetic richness of antimicrobial compound-producing pathways from sponge-associated bacteria are addressed.

  15. First report on chitinous holdfast in sponges (Porifera).

    Science.gov (United States)

    Ehrlich, Hermann; Kaluzhnaya, Oksana V; Tsurkan, Mikhail V; Ereskovsky, Alexander; Tabachnick, Konstantin R; Ilan, Micha; Stelling, Allison; Galli, Roberta; Petrova, Olga V; Nekipelov, Serguei V; Sivkov, Victor N; Vyalikh, Denis; Born, René; Behm, Thomas; Ehrlich, Andre; Chernogor, Lubov I; Belikov, Sergei; Janussen, Dorte; Bazhenov, Vasilii V; Wörheide, Gert

    2013-07-07

    A holdfast is a root- or basal plate-like structure of principal importance that anchors aquatic sessile organisms, including sponges, to hard substrates. There is to date little information about the nature and origin of sponges' holdfasts in both marine and freshwater environments. This work, to our knowledge, demonstrates for the first time that chitin is an important structural component within holdfasts of the endemic freshwater demosponge Lubomirskia baicalensis. Using a variety of techniques (near-edge X-ray absorption fine structure, Raman, electrospray ionization mas spectrometry, Morgan-Elson assay and Calcofluor White staining), we show that chitin from the sponge holdfast is much closer to α-chitin than to β-chitin. Most of the three-dimensional fibrous skeleton of this sponge consists of spicule-containing proteinaceous spongin. Intriguingly, the chitinous holdfast is not spongin-based, and is ontogenetically the oldest part of the sponge body. Sequencing revealed the presence of four previously undescribed genes encoding chitin synthases in the L. baicalensis sponge. This discovery of chitin within freshwater sponge holdfasts highlights the novel and specific functions of this biopolymer within these ancient sessile invertebrates.

  16. Impact of Eastern Caribbean Circulation Seasonality on two Reef Organisms

    Science.gov (United States)

    Cherubin, L. M.; Paris, C. B.; Baums, I. B.; Idrisi, N.

    2008-05-01

    The variability of the Caribbean current is under the influence of the fresh water input from the Orinoco and Amazon rivers. Sea Surface Salinity maps of the eastern Caribbean show the seasonal extension of the riverine fresh water across the Caribbean basin, from August to December (wet season). The plume is divided into two main cores: one flows into the Caribbean Sea mostly through the Grenada Passage where it merges with the Caribbean Current while the other core is formed further north by advection of the river plume by the North Brazil Current rings. Due to the presence of fresh water the Caribbean Sea mesoscale activity is strongly increased during the wet season. Therefore, both coral reef ecosystems and coastal flows are under the scope of the large scale flow seasonality. The impact of the flow mesoscale seasonality on reef organisms is studied through two reef organisms: (1) Reef-building coral: Genetic analyzes show that populations of the Caribbean reef-building coral, Acropora palmata, have experienced little or no recent genetic exchange between the western and eastern Caribbean. Western Puerto Rico is identified as an area of mixing between the two subregions. Using a bio- physical coupled model accounting for larvae life history traits, we verify the plausibility of a present day oceanographic barrier caused by the Caribbean Current seasonal variability in the vicinity of Mona Passage. (2) Grouper: Several grouper species form spawning aggregations at the shelf edge of the US Virgin Islands starting at the end of the wet season in December. Using ADCP current measurements and numerical simulations, unusual large 'dispersion' pulses are shown to be associated with the presence of sub-mesoscale coherent features more likely to be formed during the wet season. Spawning occurring during the dry season (January to April) is mostly tide driven, suggesting a limited dispersal.

  17. Status of coral reefs of India

    Digital Repository Service at National Institute of Oceanography (India)

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

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

  18. Biology of corals and coral reefs

    Digital Repository Service at National Institute of Oceanography (India)

    Rajkumar, R.; Parulekar, A.H.

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

  19. Sponge 'tree rings' : new indicators of ocean variability?

    International Nuclear Information System (INIS)

    Ellwood, M.; Kelly, M.

    2003-01-01

    Certain marine sponges offer a unique approach to the problem of recording environmental change. These sponges and their spicules grow by putting on concentric layers of silica material on a seasonal basis, rather like tree rings. The concentrations of certain chemicals in the surrounding water, and the growth rate of the sponge itself, are archived in the silica deposited. The information in each layer of silica can be used to deduce environmental conditions on a range of scales; years, decades and centuries. (author). 7 figs

  20. Transport of Calcareous Fragments by Reef Fishes.

    Science.gov (United States)

    Bardach, J E

    1961-01-13

    The weight of sand, coral scrapings, algal fragments, and other calcareous materials which pass through the intestines of reef fishes was calculated on a hectare-per-year basis. It was found that browsing omnivorous reef fishes which rely, in part, on a plant diet ingested and redeposited at least 2300 kg of such material on a 1-hectare study reef near Bermuda. Reasons are presented why this estimate, certainly in order of magnitude, should be applicable to coral reefs in general.

  1. Taxonomy of the Caribbean sponge Dragmacidon reticulatum (Ridley & Dendy, 1886) (Porifera, Demospongiae, Axinellida), with the description of a new species.

    Science.gov (United States)

    Zea, Sven; Pulido, Alejandra

    2016-05-25

    Although there is a long history of taxonomic investigation in Caribbean sponges, there are still many undescribed species. Furthermore, field observations and corroborating morphological analyses are revealing that what was believed to be single, somewhat variable species, may consist of two or more species, often easier to distinguish once well characterized. This is the case for Dragmacidon reticulatum (Ridley & Dendy, 1886) (Porifera, Demospongiae, Axinellida, Axinellidae), a rather well-known sponge, with an ample distribution and presence in rocky and reef environments of the tropical and subtropical Western Atlantic, with local records in the majority of the countries of the area, from Bermuda to Brazil. Field observations and a detailed review of material from different areas, including some type specimens, led us to the distinction of two different species in terms of external morphology, size of spicules, and skeletal architecture. The distinction was confirmed in the Bahamas and Santa Marta, Colombia, where the two species coexist. One of the species is Dragmacidon reticulatum sensu stricto, but for the other there is need to erect a new name, for which we propose Dragmacidon alvarezae n. sp. The purpose of the present work is to describe, illustrate and compare these two species.

  2. High rates of hybridisation reveal fragile reproductive barriers between endangered Australian sea snakes

    DEFF Research Database (Denmark)

    Sanders, Kate L; Redsted Rasmussen, Arne; Guinea, Michael L.

    2014-01-01

    designations, but revealed high frequencies of hybrids on all four reefs and individuals of pure A. fuscus ancestry only at Scott and (historically) Ashmore. Most unexpectedly, 95% of snakes sampled at Hibernia were hybrids that resembled A. laevis in phenotype, revealing a collapse of reproductive barriers...... (‘reverse speciation’) at this reef. These results have dire implications for the conservation status of A. fuscus, and highlight the fragility of reproductive barriers in a recent marine radiation....

  3. 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.

  4. Managing and sharing the escalating number of sponge "unknowns": the SpongeMaps project.

    Science.gov (United States)

    Hooper, J N A; Hall, K A; Ekins, M; Erpenbeck, D; Wörheide, G; Jolley-Rogers, G

    2013-09-01

    Contemporary collections of sponges in the Indo-west Pacific have escalated substantially due to pharmaceutical discovery, national bioregional planning, and compliance with international conventions on the seabed and its marine genetic resources beyond national jurisdictions. These partially processed operational taxonomic unit (OTU) collections now vastly outweigh the expertise available to make them better "known" via complete taxonomy, yet for many bioregions they represent the most significant body of currently available knowledge. Increasing numbers of cryptic species, previously undetected morphologically, are now being discovered by molecular and chemical analyses. The uncoordinated and fragmented nature of many previous collections, however, means that knowledge and expertise gained from a particular project are often lost to future projects without a biodiversity informatics legacy. Integrating these diverse data (GIS; OTUs; images; molecular, chemical, and other datasets) required a two-way iter