Science.gov

Sample records for acropora palmata montastraea

  1. Larval settlement preferences of Acropora palmata and Montastraea faveolata in response to diverse red algae

    NASA Astrophysics Data System (ADS)

    Ritson-Williams, R.; Arnold, S. N.; Paul, V. J.; Steneck, R. S.

    2014-03-01

    Settlement specificity can regulate recruitment but remains poorly understood for coral larvae. We studied larvae of the corals, Acropora palmata and Montastraea faveolata, to determine their rates of settlement and metamorphosis in the presence of ten species of red algae, including eight species of crustose coralline algae, one geniculated coralline and one encrusting peyssonnelid. Twenty to forty percent of larvae of A. palmata settled on coralline surfaces of Hydrolithon boergesenii, Lithoporella atlantica, Neogoniolithon affine, and Titanoderma prototypum, whereas none settled and metamorphosed on Neogoniolithon mamillare. Larvae of M. faveolata had 13-25 % settlement onto the surface of Amphiroa tribulus, H. boergesenii, N. affine, N. munitum, and T. prototypum, but had no settlement on the surface of N. mamillare, Porolithon pachydermum, and a noncoralline crust Peyssonnelia sp. Some of these algal species were common on Belizean reefs, but the species that induced the highest rates of larval settlement and metamorphosis tended to be rare and primarily found in low-light environments. The shallow coral, A. palmata, and the deeper coral, M. faveolata, both had increased larval settlement rates in the presence of only a few species of red algae found at deeper depths suggesting that patterns of coral distribution can only sometimes be related to the distribution of red algae species.

  2. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (south Florida): Reef-building corals. [Acropora cervicornis; Acropora palmata; Montastraea annularis; Montastraea cavernosa

    SciTech Connect

    Porter, J.W.

    1987-08-01

    Four species of reef-building corals are considered: elkhorn coral, staghorn coral, common star coral, and large star coral. All four species spawn annually in the fall during hurricane season. Juvenile recruitment is low in all four species. Rapid growth rates of species in the genus Acropora (10 to 20 cm/yr) contrast with slower growth rates of species in the genus Montastraea (1.0 to 2.0 cm/yr), but both species of Montastraea are also important in reef development due to their form and great longevity. Shallow-water colonies of Montastraea survive hurricanes; shallow colonies of Acropora do not. Because of their dependence on photosynthesis for all of their carbon acquisition, the Acropora species reviewed here have a more restricted depth distribution (0 to 30 m) than do the Montastraea species considered (0 to 70 m). All four species are subject to intense predation by the snail predator, Coralliophila. Species of Montastraea are susceptible to infection from blue-green algae, which produce ''black band disease;'' species of Acropora are susceptible to a different, as yet unidentified pathogen, that produces ''white-band'' disease. Increased water turbidity and sedimentation cause reduced growth rates and partial or whole mortality in all four species.

  3. The future of coral reefs in the US Virgin Islands: is Acropora palmata more likely to recover than Montastraea annularis complex?

    USGS Publications Warehouse

    Rogers, Caroline S.; Muller, Erinn; Spitzack, Tony; Miller, Jeff

    2008-01-01

    Coral diseases have played a major role in the degradation of coral reefs in the Caribbean, including those in the US Virgin Islands (USVI). In 2005, bleaching affected reefs throughout the Caribbean, and was especially severe on USVI reefs. Some corals began to regain their color as water temperatures cooled, but an outbreak of disease (primarily white plague) led to losses of over 60% of the total live coral cover. Montastraea annularis, the most abundant coral, was disproportionately affected, and decreased in relative abundance. The threatened species Acropora palmata bleached for the first time on record in the USVI but suffered less bleaching and less mortality from disease than M. annularis. Acropora palmata and M. annularis are the two most significant species in the USVI because of their structural role in the architecture of the reefs, the large size of their colonies, and their complex morphology. The future of the USVI reefs depends largely on their fate. Acropora palmata is more likely to recover than M. annularis for many reasons, including its faster growth rate, and its lower vulnerability to bleaching and disease.

  4. Settlement induction of Acropora palmata planulae by a GLW-amide neuropeptide

    NASA Astrophysics Data System (ADS)

    Erwin, P. M.; Szmant, A. M.

    2010-12-01

    Complex environmental cues dictate the settlement of coral planulae in situ; however, simple artificial cues may be all that is required to induce settlement of ex situ larval cultures for reef re-seeding and restoration projects. Neuropeptides that transmit settlement signals and initiate the metamorphic cascade have been isolated from hydrozoan taxa and shown to induce metamorphosis of reef-building Acropora spp. in the Indo-Pacific, providing a reliable and efficient settlement cue. Here, the metamorphic activity of six GLW-amide cnidarian neuropeptides was tested on larvae of the Caribbean corals Acropora palmata, Montastraea faveolata and Favia fragum. A. palmata planulae were induced to settle by the exogenous application of the neuropeptide Hym-248 (concentrations ≥1 × 10-6 M), achieving 40-80% attachment and 100% metamorphosis of competent planulae (≥6 days post-fertilization) during two spawning seasons; the remaining neuropeptides exhibited no activity. Hym-248 exposure rapidly altered larval swimming behavior (<1 h) and resulted in >96% metamorphosis after 6 h. In contrast , M. faveolata and F. fragum planulae did not respond to any GLW-amides tested, suggesting a high specificity of neuropeptide activators on lower taxonomic scales in corals. Subsequent experiments for A. palmata revealed that (1) the presence of a biofilm did not enhance attachment efficiency when coupled with Hym-248 treatment, (2) neuropeptide-induced settlement had no negative effects on early life-history developmental processes: zooxanthellae acquisition and skeletal secretion occurred within 12 days, colonial growth occurred within 36 days, and (3) Hym-248 solutions maintained metamorphic activity following storage at room temperature (10 days), indicating its utility in remote field settings. These results corroborate previous studies on Indo-Pacific Acropora spp. and extend the known metamorphic activity of Hym-248 to Caribbean acroporids. Hym-248 allows for directed and

  5. Assessment of Acropora palmata in the Mesoamerican Reef System

    PubMed Central

    Rodríguez-Martínez, Rosa E.; Banaszak, Anastazia T.; McField, Melanie D.; Beltrán-Torres, Aurora U.; Álvarez-Filip, Lorenzo

    2014-01-01

    The once-dominant shallow reef-building coral Acropora palmata has suffered drastic geographical declines in the wider Caribbean from a disease epidemic that began in the late 1970s. At present there is a lack of quantitative data to determine whether this species is recovering over large spatial scales. Here, we use quantitative surveys conducted in 107 shallow-water reef sites between 2010 and 2012 to investigate the current distribution and abundance of A. palmata along the Mesoamerican Reef System (MRS). Using historical data we also explored how the distribution and abundance of this species has changed in the northern portion of the MRS between 1985 and 2010–2012. A. palmata was recorded in only a fifth of the surveyed reef sites in 2010–2012. In the majority of these reef sites the presence of A. palmata was patchy and rare. Only one site (Limones reef), in the northernmost portion of the MRS, presented considerably high A. palmata cover (mean: 34.7%, SD: 24.5%). At this site, the size-frequency distribution of A. palmata colonies was skewed towards small colony sizes; 84% of the colonies were healthy, however disease prevalence increased with colony size. A comparison with historical data showed that in the northern portion of the MRS, in 1985, A. palmata occurred in 74% of the 31 surveyed sites and had a mean cover of 7.7% (SD = 9.0), whereas in 2010–2012 this species was recorded in 48% of the sites with a mean cover of 2.9% (SD = 7.5). A. palmata populations along the MRS are failing to recover the distribution and abundance they had prior to the 1980s. Investigating the biological (e.g., population genetics) and environmental conditions (e.g., sources of stress) of the few standing reefs with relatively high A. palmata cover is crucial for the development of informed restoration models for this species. PMID:24763319

  6. ETIOLOGY OF WHITE POX, A LETHAL DISEASE OF THE CARIBBEAN ELKHORN CORAL, ACROPORA PALMATA.

    EPA Science Inventory

    Populations of the shallow-water Caribbean elkhorn coral, Acropora palmata, are being decimated by white pox disease, with losses in the Florida Keys typically in excess of 70%. Tissue loss is rapid, averaging 2.5 cm2 day-1. A bacterium isolated from diseased A. palmata was shown...

  7. Human Pathogen Shown to Cause Disease in the Threatened Eklhorn Coral Acropora palmata

    PubMed Central

    Sutherland, Kathryn Patterson; Shaban, Sameera; Joyner, Jessica L.; Porter, James W.; Lipp, Erin K.

    2011-01-01

    Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch's postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine “reverse zoonosis” involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival. PMID:21858132

  8. Attributing mortality among drivers of population decline in Acropora palmata in the Florida Keys (USA)

    NASA Astrophysics Data System (ADS)

    Williams, D. E.; Miller, M. W.

    2012-06-01

    Acropora palmata populations have experienced steep declines over the past 30 years. Although numerous culprits are recognized, their relative contributions to the decline are poorly quantified, making it difficult to prioritize effective conservation measures. In 2004, a demographic monitoring program was implemented in the Florida Keys (USA), aimed at determining the relative importance of various stressors affecting A. palmata. A subset of randomly selected A. palmata colonies within 15 fore-reef plots was tagged and surveyed three to four times per year over 7 years. Colony size, live tissue, prevalence of disease, snail ( Coralliophila abbreviata) predation, physical damage and other conditions were assessed at each survey. The estimated effect of each condition causing recent mortality was ranked, and together, these parameters were used to attribute the population-level tissue loss associated with each condition. In addition, all new colonies in the study plots were counted and assessed annually in order to track trends in total colony count and live tissue abundance. Between 2004 and 2010, the study population has shown more than 50% decline in live area from three main conditions: fragmentation, disease and snail predation. Approximately half of this decline occurred during the catastrophic 2005 hurricane season from which recovery has been minimal. Meanwhile, colony abundance has shown gradual decline throughout the study. Snail predation was the most prevalent condition. However, it ranked third in attributed tissue loss, behind breakage that occurred during the 2005 hurricane season, and disease. Thermal bleaching of A. palmata was not observed during this study. Because mortality continues to outpace recruitment and growth, intervention to ameliorate losses to the more manageable threats including predation and breakage could result in substantial conservation of live tissue, buying time for the abatement of less tractable threats to A. palmata

  9. Potential inhibitors to recovery of Acropora palmata populations in St. John, US Virgin Islands

    USGS Publications Warehouse

    Grober-Dunsmore, R.; Bonito, V.; Frazer, T.K.

    2006-01-01

    Populations of Acropora palmata in the Caribbean were decimated in the 1970s and 1980s, with little apparent signs of recovery until the late 1990s. Here, we document an increase in A. palmata colonies between 2001 and 2003 at 8 of 11 monitoring sites in waters adjacent to the island of St. John, US Virgin Islands. The shallow waters along the NW coast of the island exhibited the greatest increase in colony abundance, perhaps due to greater larval supply and/or conditions that favor settlement and subsequent survivorship. Of concern, however, is the lack of survival of large colonies (at all sites), which are most frequently affected by stressors (e.g. Coralliophila abbreviata, damselfishes, active disease) and are most likely to be remnants (colonies with discontinuous, living coral-tissue over an existing coral framework). Predation by C. abbreviata and active coral disease may directly contribute to the development of these remnant colonies. In addition, we recorded damage to colonies attributed to damselfishes and raise the possibility that these territorial reef-inhabitants act as vectors in the transmission of coral disease. While the incidence of disease around St. John is generally low, it may persist as a ubiquitous, chronic stress. Finally, because stressors are more prevalent on large colonies and in high-density stands, they have the potential to inhibit the recovery of A. palmata populations to their historic condition. ?? Inter-Research 2006.

  10. Early signs of recovery of Acropora palmata in St. John, US Virgin Islands

    USGS Publications Warehouse

    Muller, E.M.; Rogers, Caroline S.; van Woesik, R.

    2014-01-01

    Since the 1980s, diseases have caused significant declines in the population of the threatened Caribbean coral Acropora palmata. Yet it is largely unknown whether the population densities have recovered from these declines and whether there have been any recent shifts in size-frequency distributions toward large colonies. It is also unknown whether colony size influences the risk of disease infection, the most common stressor affecting this species. To address these unknowns, we examined A. palmata colonies at ten sites around St. John, US Virgin Islands, in 2004 and 2010. The prevalence of white-pox disease was highly variable among sites, ranging from 0 to 53 %, and this disease preferentially targeted large colonies. We found that colony density did not significantly change over the 6-year period, although six out of ten sites showed higher densities through time. The size-frequency distributions of coral colonies at all sites were positively skewed in both 2004 and 2010, however, most sites showed a temporal shift toward more large-sized colonies. This increase in large-sized colonies occurred despite the presence of white-pox disease, a severe bleaching event, and several storms. This study provides evidence of slow recovery of the A. palmata population around St. John despite the persistence of several stressors.

  11. Proteomic analysis of bleached and unbleached Acropora palmata, a threatened coral species of the Caribbean.

    PubMed

    Ricaurte, Martha; Schizas, Nikolaos V; Ciborowski, Pawel; Boukli, Nawal M

    2016-06-15

    There has been an increase in the scale and frequency of coral bleaching around the world due mainly to changes in sea temperature. This may occur at large scales, often resulting in significant decline in coral coverage. In order to understand the molecular and cellular basis of the ever-increasing incidence of coral bleaching, we have undertaken a comparative proteomic approach with the endangered Caribbean coral Acropora palmata. Using a proteomic tandem mass spectrometry approach, we identified 285 and 321 expressed protein signatures in bleached and unbleached A. palmata colonies, respectively, in southwestern Puerto Rico. Overall the expression level of 38 key proteins was significantly different between bleached and unbleached corals. A wide range of proteins was detected and categorized, including transcription factors involved mainly in heat stress/UV responses, immunity, apoptosis, biomineralization, the cytoskeleton, and endo-exophagocytosis. The results suggest that for bleached A. palmata, there was an induced differential protein expression response compared with those colonies that did not bleach under the same environmental conditions. PMID:27105725

  12. Microbial composition of biofilms associated with lithifying rubble of Acropora palmata branches.

    PubMed

    Beltrán, Yislem; Cerqueda-García, Daniel; Taş, Neslihan; Thomé, Patricia E; Iglesias-Prieto, Roberto; Falcón, Luisa I

    2016-01-01

    Coral reefs are among the most productive ecosystems on the planet, but are rapidly declining due to global-warming-mediated changes in the oceans. Particularly for the Caribbean region, Acropora sp. stony corals have lost ∼80% of their original coverage, resulting in vast extensions of dead coral rubble. We analyzed the microbial composition of biofilms that colonize and lithify dead Acropora palmata rubble in the Mexican Caribbean and identified the microbial assemblages that can persist under scenarios of global change, including high temperature and low pH. Lithifying biofilms have a mineral composition that includes aragonite and magnesium calcite (16 mole% MgCO(3)) and calcite, while the mineral phase corresponding to coral skeleton is basically aragonite. Microbial composition of the lithifying biofilms are different in comparison to surrounding biotopes, including a microbial mat, water column, sediments and live A. palmata microbiome. Significant shifts in biofilm composition were detected in samples incubated in mesocosms. The combined effect of low pH and increased temperature showed a strong effect after two-week incubations for biofilm composition. Findings suggest that lithifying biofilms could remain as a secondary structure on reef rubble possibly impacting the functional role of coral reefs. PMID:26705570

  13. Microbial composition of biofilms associated with lithifying rubble of Acropora palmata branches.

    PubMed

    Beltrán, Yislem; Cerqueda-García, Daniel; Taş, Neslihan; Thomé, Patricia E; Iglesias-Prieto, Roberto; Falcón, Luisa I

    2016-01-01

    Coral reefs are among the most productive ecosystems on the planet, but are rapidly declining due to global-warming-mediated changes in the oceans. Particularly for the Caribbean region, Acropora sp. stony corals have lost ∼80% of their original coverage, resulting in vast extensions of dead coral rubble. We analyzed the microbial composition of biofilms that colonize and lithify dead Acropora palmata rubble in the Mexican Caribbean and identified the microbial assemblages that can persist under scenarios of global change, including high temperature and low pH. Lithifying biofilms have a mineral composition that includes aragonite and magnesium calcite (16 mole% MgCO(3)) and calcite, while the mineral phase corresponding to coral skeleton is basically aragonite. Microbial composition of the lithifying biofilms are different in comparison to surrounding biotopes, including a microbial mat, water column, sediments and live A. palmata microbiome. Significant shifts in biofilm composition were detected in samples incubated in mesocosms. The combined effect of low pH and increased temperature showed a strong effect after two-week incubations for biofilm composition. Findings suggest that lithifying biofilms could remain as a secondary structure on reef rubble possibly impacting the functional role of coral reefs.

  14. The role of skeletal micro-architecture in diagenesis and dating of Acropora palmata

    NASA Astrophysics Data System (ADS)

    Tomiak, P. J.; Andersen, M. B.; Hendy, E. J.; Potter, E. K.; Johnson, K. G.; Penkman, K. E. H.

    2016-06-01

    Past variations in global sea-level reflect continental ice volume, a crucial factor for understanding the Earth's climate system. The Caribbean coral Acropora palmata typically forms dense stands in very shallow water and therefore fossil samples mark past sea-level. Uranium-series methods are commonly used to establish a chronology for fossil coral reefs, but are compromised by post mortem diagenetic changes to coral skeleton. Current screening approaches are unable to identify all altered samples, whilst models that attempt to correct for 'open-system' behaviour are not applicable across all diagenetic scenarios. In order to better understand how U-series geochemistry varies spatially with respect to diagenetic textures, we examine these aspects in relation to skeletal micro-structure and intra-crystalline amino acids, comparing an unaltered modern coral with a fossil A. palmata colony containing zones of diagenetic alteration (secondary overgrowth of aragonite, calcite cement and dissolution features). We demonstrate that the process of skeletogenesis in A. palmata causes heterogeneity in porosity, which can account for the observed spatial distribution of diagenetic features; this in turn explains the spatially-systematic trends in U-series geochemistry and consequently, U-series age. We propose a scenario that emphasises the importance of through-flow of meteoric waters, invoking both U-loss and absorption of mobilised U and Th daughter isotopes. We recommend selective sampling of low porosity A. palmata skeleton to obtain the most reliable U-series ages. We demonstrate that intra-crystalline amino acid racemisation (AAR) can be applied as a relative dating tool in Pleistocene A. palmata samples that have suffered heavy dissolution and are therefore unsuitable for U-series analyses. Based on relatively high intra-crystalline concentrations and appropriate racemisation rates, glutamic acid and valine are most suited to dating mid-late Pleistocene A. palmata

  15. Is Acropora palmata recovering? A case study in Los Roques National Park, Venezuela.

    PubMed

    Croquer, Aldo; Cavada-Blanco, Francoise; Zubillaga, Ainhoa L; Agudo-Adriani, Esteban A; Sweet, Michael

    2016-01-01

    Eight years ago (2007), the distribution and status of Acropora palmata was quantified throughout Los Roques archipelago in Venezuela. The aim was to produce a baseline study for this species which combined population genetics with demographic data. The results highlighted that A. palmata had the potential to recover in at least 6 out of 10 sites surveyed. Recovery potential was assumed to be high at sites with a relatively high abundance of the coral, low disease prevalence, high genetic diversity, and high rates of sexual reproduction. However, as noted, Zubillaga et al. (2008) realized recovery was still strongly dependent on local and regional stressors. In 2014 (this study), the status of A. palmata was re-evaluated at Los Roques. We increased the number of sites from 10 in the original baseline study to 106. This allowed us to assess the population status throughout the entirety of the MPA. Furthermore, we also identified local threats that may have hindered population recovery. Here, we show that A. palmata now has a relatively restricted distribution throughout the park, only occurring in 15% of the sites surveyed. Large stands of old dead colonies were common throughout the archipelago; a result which demonstrates that this species has lost almost 50% of its original distribution over the past decades. The majority of corals recorded were large adults (∼2 m height), suggesting that these older colonies might be less susceptible or more resilient to local and global threats. However, 45% of these surviving colonies showed evidence of partial mortality and degradation of living tissues. Interestingly, the greatest increase in partial mortality occurred at sites with the lowest levels of protection ([Formula: see text]; df = 4, p < 0.05). This may suggest there is a positive role of small scale marine management in assisting reef recovery. We also recorded a significant reduction ([Formula: see text]; df = 8; p < 0.05) in the density of A. palmata in sites

  16. Is Acropora palmata (elkhorn coral) making a comeback in the Virgin Islands?

    USGS Publications Warehouse

    Rogers, Caroline S.

    2000-01-01

    White band disease (WBD) ravaged Acropora palmata (elkhorn coral) on many coral reefs in the Caribbean in the late 1970’s and 1980’s, including those around St. John and St. Croix, U. S. Virgin Islands—USVI (Gladfelter 1982, Rogers 1985). Quantitative data, photographs, and anecdotal observations indicate WBD killed large stands of elkhorn coral in the USVI from about 1976 until sometime in the late 1980’s. Branching Acroporid species, which are most susceptible to WBD, are also the most vulnerable to storm damage (Rogers et al. 1982). Since 1979, eight hurricanes have passed near or over the USVI. Because elkhorn coral contributed most of the living coral and determined the physical structure of many shallow reef zones, its demise dramatically altered many areas. But now, some of the reefs in the Virgin Islands once again have large, actively growing colonies of this important, reef-building species.

  17. Genotypic variation influences reproductive success and thermal stress tolerance in the reef building coral, Acropora palmata

    NASA Astrophysics Data System (ADS)

    Baums, I. B.; Devlin-Durante, M. K.; Polato, N. R.; Xu, D.; Giri, S.; Altman, N. S.; Ruiz, D.; Parkinson, J. E.; Boulay, J. N.

    2013-09-01

    The branching coral Acropora palmata is a foundation species of Caribbean reefs that has been decimated in recent decades by anthropogenic and natural stressors. Declines in population density and genotypic diversity likely reduce successful sexual reproduction in this self-incompatible hermaphrodite and might impede recovery. We investigated variation among genotypes in larval development under thermally stressful conditions. Six two-parent crosses and three four-parent batches were reared under three temperatures and sampled over time. Fertilization rates differed widely with two-parent crosses having lower fertilization rates (5-56 %, mean 22 % ± 22 SD) than batches (from 31 to 87 %, mean 59 % ± 28 SD). Parentage analysis of larvae in batch cultures showed differences in gamete compatibility among parents, coinciding with significant variation in both sperm morphology and egg size. While all larval batches developed more rapidly at increased water temperatures, rate of progression through developmental stages varied among batches, as did swimming speed. Together, these results indicate that loss of genotypic diversity exacerbates already severe limitations in sexual reproductive success of A. palmata. Nevertheless, surviving parental genotypes produce larvae that do vary in their phenotypic response to thermal stress, with implications for adaptation, larval dispersal and population connectivity in the face of warming sea surface temperatures.

  18. Utilization of Mucus from the Coral Acropora palmata by the Pathogen Serratia marcescens and by Environmental and Coral Commensal Bacteria▿ †

    PubMed Central

    Krediet, Cory J.; Ritchie, Kim B.; Cohen, Matthew; Lipp, Erin K.; Sutherland, Kathryn Patterson; Teplitski, Max

    2009-01-01

    In recent years, diseases of corals caused by opportunistic pathogens have become widespread. How opportunistic pathogens establish on coral surfaces, interact with native microbiota, and cause disease is not yet clear. This study compared the utilization of coral mucus by coral-associated commensal bacteria (“Photobacterium mandapamensis” and Halomonas meridiana) and by opportunistic Serratia marcescens pathogens. S. marcescens PDL100 (a pathogen associated with white pox disease of Acroporid corals) grew to higher population densities on components of mucus from the host coral. In an in vitro coculture on mucus from Acropora palmata, S. marcescens PDL100 isolates outgrew coral isolates. The white pox pathogen did not differ from other bacteria in growth on mucus from a nonhost coral, Montastraea faveolata. The ability of S. marcescens to cause disease in acroporid corals may be due, at least in part, to the ability of strain PDL100 to build to higher population numbers within the mucus surface layer of its acroporid host. During growth on mucus from A. palmata, similar glycosidase activities were present in coral commensal bacteria, in S. marcescens PDL100, and in environmental and human isolates of S. marcescens. The temporal regulation of these activities during growth on mucus, however, was distinct in the isolates. During early stages of growth on mucus, enzymatic activities in S. marcescens PDL100 were most similar to those in coral commensals. After overnight incubation on mucus, enzymatic activities in a white pox pathogen were most similar to those in pathogenic Serratia strains isolated from human mucosal surfaces. PMID:19395569

  19. Is Acropora palmata recovering? A case study in Los Roques National Park, Venezuela

    PubMed Central

    Cavada-Blanco, Francoise; Zubillaga, Ainhoa L.; Agudo-Adriani, Esteban A.; Sweet, Michael

    2016-01-01

    Eight years ago (2007), the distribution and status of Acropora palmata was quantified throughout Los Roques archipelago in Venezuela. The aim was to produce a baseline study for this species which combined population genetics with demographic data. The results highlighted that A. palmata had the potential to recover in at least 6 out of 10 sites surveyed. Recovery potential was assumed to be high at sites with a relatively high abundance of the coral, low disease prevalence, high genetic diversity, and high rates of sexual reproduction. However, as noted, Zubillaga et al. (2008) realized recovery was still strongly dependent on local and regional stressors. In 2014 (this study), the status of A. palmata was re-evaluated at Los Roques. We increased the number of sites from 10 in the original baseline study to 106. This allowed us to assess the population status throughout the entirety of the MPA. Furthermore, we also identified local threats that may have hindered population recovery. Here, we show that A. palmata now has a relatively restricted distribution throughout the park, only occurring in 15% of the sites surveyed. Large stands of old dead colonies were common throughout the archipelago; a result which demonstrates that this species has lost almost 50% of its original distribution over the past decades. The majority of corals recorded were large adults (∼2 m height), suggesting that these older colonies might be less susceptible or more resilient to local and global threats. However, 45% of these surviving colonies showed evidence of partial mortality and degradation of living tissues. Interestingly, the greatest increase in partial mortality occurred at sites with the lowest levels of protection (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${X}_{o}^{2

  20. Spatial Homogeneity of Bacterial Communities Associated with the Surface Mucus Layer of the Reef-Building Coral Acropora palmata.

    PubMed

    Kemp, Dustin W; Rivers, Adam R; Kemp, Keri M; Lipp, Erin K; Porter, James W; Wares, John P

    2015-01-01

    Coral surface mucus layer (SML) microbiota are critical components of the coral holobiont and play important roles in nutrient cycling and defense against pathogens. We sequenced 16S rRNA amplicons to examine the structure of the SML microbiome within and between colonies of the threatened Caribbean reef-building coral Acropora palmata in the Florida Keys. Samples were taken from three spatially distinct colony regions--uppermost (high irradiance), underside (low irradiance), and the colony base--representing microhabitats that vary in irradiance and water flow. Phylogenetic diversity (PD) values of coral SML bacteria communities were greater than surrounding seawater and lower than adjacent sediment. Bacterial diversity and community composition was consistent among the three microhabitats. Cyanobacteria, Bacteroidetes, Alphaproteobacteria, and Proteobacteria, respectively were the most abundant phyla represented in the samples. This is the first time spatial variability of the surface mucus layer of A. palmata has been studied. Homogeneity in the microbiome of A. palmata contrasts with SML heterogeneity found in other Caribbean corals. These findings suggest that, during non-stressful conditions, host regulation of SML microbiota may override diverse physiochemical influences induced by the topographical complexity of A. palmata. Documenting the spatial distribution of SML microbes is essential to understanding the functional roles these microorganisms play in coral health and adaptability to environmental perturbations. PMID:26659364

  1. Bleaching increases likelihood of disease on Acropora palmata (Lamarck) in Hawksnest Bay, St John, US Virgin Islands

    USGS Publications Warehouse

    Muller, E.M.; Rogers, C.S.; Spitzack, Anthony S.; van Woesik, R.

    2008-01-01

    Anomalously high water temperatures may enhance the likelihood of coral disease outbreaks by increasing the abundance or virulence of pathogens, or by increasing host susceptibility. This study tested the compromised-host hypothesis, and documented the relationship between disease and temperature, through monthly monitoring of Acropora palmata colonies from May 2004 to December 2006, in Hawksnest Bay, St John, US Virgin Islands (USVI). Disease prevalence and the rate of change in prevalence showed a positive linear relationship with water temperature and rate of change in water temperature, respectively, but only in 2005 during prolonged periods of elevated temperature. Both bleached and unbleached colonies showed a positive relationship between disease prevalence and temperature in 2005, but the average area of disease-associated mortality increased only for bleached corals, indicating host susceptibility, rather than temperature per se, influenced disease severity on A. palmata. ?? 2007 Springer-Verlag.

  2. Bleaching increases likelihood of disease on Acropora palmata (Lamarck) in Hawksnest Bay, St John, US Virgin Islands

    USGS Publications Warehouse

    Muller, E.M.; Rogers, Caroline S.; Spitzack, Anthony S.; van Woesik, R.

    2007-01-01

    Anomalously high water temperatures may enhance the likelihood of coral disease outbreaks by increasing the abundance or virulence of pathogens, or by increasing host susceptibility. This study tested the compromised-host hypothesis, and documented the relationship between disease and temperature, through monthly monitoring of Acropora palmata colonies from May 2004 to December 2006, in Hawksnest Bay, St John, US Virgin Islands (USVI). Disease prevalence and the rate of change in prevalence showed a positive linear relationship with water temperature and rate of change in water temperature, respectively, but only in 2005 during prolonged periods of elevated temperature. Both bleached and unbleached colonies showed a positive relationship between disease prevalence and temperature in 2005, but the average area of disease-associated mortality increased only for bleached corals, indicating host susceptibility, rather than temperature per se, influenced disease severity on A. palmata.

  3. Differential larval settlement responses of Porites astreoides and Acropora palmata in the presence of the green alga Halimeda opuntia

    NASA Astrophysics Data System (ADS)

    Olsen, K.; Sneed, J. M.; Paul, V. J.

    2016-06-01

    Settlement is critical to maintaining coral cover on reefs, yet interspecific responses of coral planulae to common benthic macroalgae are not well characterized. Larval survival and settlement of two Caribbean reef-building corals, the broadcast-spawner Acropora palmata and the planulae-brooder Porites astreoides, were quantified following exposure to plastic algae controls and the green macroalga Halimeda opuntia. Survival and settlement rates were not significantly affected by the presence of H. opuntia in either species. However, ~10 % of P. astreoides larvae settled on the surface of the macroalga, whereas larvae of A. palmata did not. It is unlikely that corals that settle on macroalgae will survive post-settlement; therefore, H. opuntia may reduce the number of P. astreoides and other non-discriminatory larvae that survive to adulthood. Our results suggest that the presence of macroalgae on impacted reefs can have unexpected repercussions for coral recruitment and highlight discrepancies in settlement specificity between corals with distinct life history strategies.

  4. Ocean acidification compromises recruitment success of the threatened Caribbean coral Acropora palmata.

    PubMed

    Albright, Rebecca; Mason, Benjamin; Miller, Margaret; Langdon, Chris

    2010-11-23

    Ocean acidification (OA) refers to the ongoing decline in oceanic pH resulting from the uptake of atmospheric CO(2). Mounting experimental evidence suggests that OA will have negative consequences for a variety of marine organisms. Whereas the effect of OA on the calcification of adult reef corals is increasingly well documented, effects on early life history stages are largely unknown. Coral recruitment, which necessitates successful fertilization, larval settlement, and postsettlement growth and survivorship, is critical to the persistence and resilience of coral reefs. To determine whether OA threatens successful sexual recruitment of reef-building corals, we tested fertilization, settlement, and postsettlement growth of Acropora palmata at pCO(2) levels that represent average ambient conditions during coral spawning (∼400 μatm) and the range of pCO(2) increases that are expected to occur in this century [∼560 μatm (mid-CO(2)) and ∼800 μatm (high-CO(2))]. Fertilization, settlement, and growth were all negatively impacted by increasing pCO(2), and impairment of fertilization was exacerbated at lower sperm concentrations. The cumulative impact of OA on fertilization and settlement success is an estimated 52% and 73% reduction in the number of larval settlers on the reef under pCO(2) conditions projected for the middle and the end of this century, respectively. Additional declines of 39% (mid-CO(2)) and 50% (high-CO(2)) were observed in postsettlement linear extension rates relative to controls. These results suggest that OA has the potential to impact multiple, sequential early life history stages, thereby severely compromising sexual recruitment and the ability of coral reefs to recover from disturbance.

  5. Disease prevalence and snail predation associated with swell-generated damage on the threatened coral, Acropora palmata (Lamarck)

    USGS Publications Warehouse

    Bright, Allan J.; Rogers, Caroline S.; Brandt, Marilyn E.; Muller, Erinn; Smith, Tyler B.

    2016-01-01

    Disturbances such as tropical storms cause coral mortality and reduce coral cover as a direct result of physical damage. Storms can be one of the most important disturbances in coral reef ecosystems, and it is crucial to understand their long-term impacts on coral populations. The primary objective of this study was to determine trends in disease prevalence and snail predation on damaged and undamaged colonies of the threatened coral species, Acropora palmata, following an episode of heavy ocean swells in the US Virgin Islands (USVI). At three sites on St. Thomas and St. John, colonies of A. palmata were surveyed monthly over 1 year following a series of large swells in March 2008 that fragmented 30–93% of colonies on monitored reefs. Post-disturbance surveys conducted from April 2008 through March 2009 showed that swell-generated damage to A. palmata caused negative indirect effects that compounded the initial direct effects of physical disturbance. During the 12 months after the swell event, white pox disease prevalence was 41% higher for colonies that sustained damage from the swells than for undamaged colonies (df = 207, p = 0.01) with greatest differences in disease prevalence occurring during warm water months. In addition, the corallivorous snail, Coralliophila abbreviata, was 46% more abundant on damaged corals than undamaged corals during the 12 months after the swell event (df = 207, p = 0.006).

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Ecological and genetic data indicate recovery of the endangered coral Acropora palmata in Los Roques, Southern Caribbean

    NASA Astrophysics Data System (ADS)

    Zubillaga, A. L.; Márquez, L. M.; Cróquer, A.; Bastidas, C.

    2008-03-01

    The rapid decline of Acropora cervicornis and Acropora palmata has often been linked with coral reef deterioration in the Caribbean; yet, it remains controversial whether these species are currently recovering or still declining. In this study, the status of ten populations of A. palmata in Los Roques National Park (LRNP), Venezuela is presented. Six of these populations showed signs of recovery. Ten 80 m2 belt-transects were surveyed at each of the ten reef sites. Within belt-transects, each colony was measured (maximum diameter and height) and its status (healthy, diseased or injured) was recorded. Populations in recovery were defined by a dominance of small to medium-sized colonies in densities >1 colony per 10 m2, together with 75% undamaged colonies, a low prevalence of diseases (<10%), and a low density of predators (0.25 snails per colony). Based on allozyme analysis of seven polymorphic loci in four populations ( N = 30), a moderate to high-genetic connectivity among these populations ( F ST = 0.048) was found with a predominance of sexual over asexual reproduction ( N* : N = 1; N go : N = 0.93-1). Both ecological and molecular data support a good prognosis for the recovery of this species in Los Roques.

  8. Bleaching, disease and recovery in the threatened scleractinian coral Acropora palmata in St. John, US Virgin Islands: 2003-2010

    USGS Publications Warehouse

    Rogers, C.S.; Muller, E.M.

    2012-01-01

    A long-term study of the scleractinian coral Acropora palmata in the US Virgin Islands (USVI) showed that diseases, particularly white pox, are limiting the recovery of this threatened species. Colonies of A. palmata in Haulover Bay, within Virgin Islands National Park, St. John, were examined monthly in situ for signs of disease and other stressors from January 2003 through December 2009. During the study, 89.9 % of the colonies (n = 69) exhibited disease, including white pox (87 %), white band (13 %), and unknown (9 %). Monthly disease prevalence ranged from 0 to 57 %, and disease was the most significant cause of complete colony mortality (n = 17). A positive correlation was found between water temperature and disease prevalence, but not incidence. Annual average disease prevalence and incidence remained constant during the study. Colonies generally showed an increase in the estimated amount of total living tissue from growth, but 25 (36.2 %) of the colonies died. Acropora palmata bleached in the USVI for the first time during the 2005 Caribbean bleaching event. Only one of the 23 colonies that bleached appeared to die directly from bleaching. In 2005, corals that bleached had greater disease prevalence than those that did not bleach. Just over half (52 %) of the colonies incurred some physical damage. Monitoring of fragments (broken branches) that were generated by physical damage through June 2007 showed that 46.1 % died and 28.4 % remained alive; the fragments that attached to the substrate survived longer than those that did not. Recent surveys showed an increase in the total number of colonies within the reef area, formed from both asexual and sexual reproduction. Genotype analysis of 48 of the originally monitored corals indicated that 43 grew from sexual recruits supporting the conclusion that both asexual and sexual reproduction are contributing to an increase in colony density at this site.

  9. Bleaching, disease and recovery in the threatened scleractinian coral Acropora palmata in St. John, US Virgin Islands: 2003-2010

    NASA Astrophysics Data System (ADS)

    Rogers, C. S.; Muller, E. M.

    2012-09-01

    A long-term study of the scleractinian coral Acropora palmata in the US Virgin Islands (USVI) showed that diseases, particularly white pox, are limiting the recovery of this threatened species. Colonies of A. palmata in Haulover Bay, within Virgin Islands National Park, St. John, were examined monthly in situ for signs of disease and other stressors from January 2003 through December 2009. During the study, 89.9 % of the colonies ( n = 69) exhibited disease, including white pox (87 %), white band (13 %), and unknown (9 %). Monthly disease prevalence ranged from 0 to 57 %, and disease was the most significant cause of complete colony mortality ( n = 17). A positive correlation was found between water temperature and disease prevalence, but not incidence. Annual average disease prevalence and incidence remained constant during the study. Colonies generally showed an increase in the estimated amount of total living tissue from growth, but 25 (36.2 %) of the colonies died. Acropora palmata bleached in the USVI for the first time during the 2005 Caribbean bleaching event. Only one of the 23 colonies that bleached appeared to die directly from bleaching. In 2005, corals that bleached had greater disease prevalence than those that did not bleach. Just over half (52 %) of the colonies incurred some physical damage. Monitoring of fragments (broken branches) that were generated by physical damage through June 2007 showed that 46.1 % died and 28.4 % remained alive; the fragments that attached to the substrate survived longer than those that did not. Recent surveys showed an increase in the total number of colonies within the reef area, formed from both asexual and sexual reproduction. Genotype analysis of 48 of the originally monitored corals indicated that 43 grew from sexual recruits supporting the conclusion that both asexual and sexual reproduction are contributing to an increase in colony density at this site.

  10. Systematic Analysis of White Pox Disease in Acropora palmata of the Florida Keys and Role of Serratia marcescens

    PubMed Central

    Joyner, Jessica L.; Sutherland, Kathryn P.; Kemp, Dustin W.; Berry, Brett; Griffin, Ashton; Porter, James W.; Amador, Molly H. B.; Noren, Hunter K. G.

    2015-01-01

    White pox disease (WPD) affects the threatened elkhorn coral, Acropora palmata. Owing in part to the lack of a rapid and simple diagnostic test, there have been few systematic assessments of the prevalence of acroporid serratiosis (caused specifically by Serratia marcescens) versus general WPD signs. Six reefs in the Florida Keys were surveyed between 2011 and 2013 to determine the disease status of A. palmata and the prevalence of S. marcescens. WPD was noted at four of the six reefs, with WPD lesions found on 8 to 40% of the colonies surveyed. S. marcescens was detected in 26.9% (7/26) of the WPD lesions and in mucus from apparently healthy colonies both during and outside of disease events (9%; 18/201). S. marcescens was detected with greater frequency in A. palmata than in the overlying water column, regardless of disease status (P = 0.0177). S. marcescens could not be cultured from A. palmata but was isolated from healthy colonies of other coral species and was identified as pathogenic pulsed-field gel electrophoresis type PDR60. WPD lesions were frequently observed on the reef, but unlike in prior outbreaks, no whole-colony death was observed. Pathogenic S. marcescens was circulating on the reef but did not appear to be the primary pathogen in these recent WPD episodes, suggesting that other pathogens or stressors may contribute to signs of WPD. Results highlight the critical importance of diagnostics in coral disease investigations, especially given that field manifestation of disease may be similar, regardless of the etiological agent. PMID:25911491

  11. Systematic Analysis of White Pox Disease in Acropora palmata of the Florida Keys and Role of Serratia marcescens.

    PubMed

    Joyner, Jessica L; Sutherland, Kathryn P; Kemp, Dustin W; Berry, Brett; Griffin, Ashton; Porter, James W; Amador, Molly H B; Noren, Hunter K G; Lipp, Erin K

    2015-07-01

    White pox disease (WPD) affects the threatened elkhorn coral, Acropora palmata. Owing in part to the lack of a rapid and simple diagnostic test, there have been few systematic assessments of the prevalence of acroporid serratiosis (caused specifically by Serratia marcescens) versus general WPD signs. Six reefs in the Florida Keys were surveyed between 2011 and 2013 to determine the disease status of A. palmata and the prevalence of S. marcescens. WPD was noted at four of the six reefs, with WPD lesions found on 8 to 40% of the colonies surveyed. S. marcescens was detected in 26.9% (7/26) of the WPD lesions and in mucus from apparently healthy colonies both during and outside of disease events (9%; 18/201). S. marcescens was detected with greater frequency in A. palmata than in the overlying water column, regardless of disease status (P = 0.0177). S. marcescens could not be cultured from A. palmata but was isolated from healthy colonies of other coral species and was identified as pathogenic pulsed-field gel electrophoresis type PDR60. WPD lesions were frequently observed on the reef, but unlike in prior outbreaks, no whole-colony death was observed. Pathogenic S. marcescens was circulating on the reef but did not appear to be the primary pathogen in these recent WPD episodes, suggesting that other pathogens or stressors may contribute to signs of WPD. Results highlight the critical importance of diagnostics in coral disease investigations, especially given that field manifestation of disease may be similar, regardless of the etiological agent.

  12. Culture-dependent and culture-independent analyses reveal no prokaryotic community shifts or recovery of Serratia marcescens in Acropora palmata with white pox disease.

    PubMed

    Lesser, Michael P; Jarett, Jessica K

    2014-06-01

    Recently, the etiological agent of white pox (WP) disease, also known as acroporid serratiosis, in the endangered coral Acropora palmata is the enteric bacterium Serratia marcescens with the source being localized sewage release onto coastal coral reef communities. Here, we show that both culture-dependent and culture-independent approaches could not recover this bacterium from samples of tissue and mucus from A. palmata colonies affected by WP disease in the Bahamas, or seawater collected adjacent to A. palmata colonies. Additionally, a metagenetic 16S rRNA pyrosequencing study shows no significant difference in the bacterial communities of coral tissues with and without WP lesions. As recent studies have shown for other coral diseases, S. marcescens cannot be identified in all cases of WP disease in several geographically separated populations of A. palmata with the same set of signs. As a result, its identification as the etiological agent of WP disease, and cause of a reverse zoonosis, cannot be broadly supported. However, the prevalence of WP disease associated with S. marcescens does appear to be associated with proximity to population centers, and research efforts should be broadened to examine this association, and to identify other causes of this syndrome.

  13. Younger Dryas sea level and meltwater pulse 1B recorded in Barbados reef crest coral Acropora palmata

    NASA Astrophysics Data System (ADS)

    Abdul, N. A.; Mortlock, R. A.; Wright, J. D.; Fairbanks, R. G.

    2016-02-01

    The Younger Dryas climate event occurred during the middle of the last deglacial cycle and is marked by an abrupt shift in the North Atlantic polar front almost to its former glacial position, trending east to west. Using high-precision and high-accuracy U-Th-dated Barbados reef crest coral, Acropora palmata, we generate a detailed sea level record from 13.9 to 9000 years before present (kyr B.P.) and reconstruct the ice volume response to the Younger Dryas cooling. From the mid-Allerød (13.9 kyr B.P.) to the end of the Younger Dryas (11.65 kyr B.P.), rates of sea level rise decreased smoothly from 20 mm yr-1 to 4 mm yr-1, culminating in a 400 year "slow stand" before accelerating into meltwater pulse 1B (MWP-1B). The MWP-1B event at Barbados is better constrained as beginning by 11.45 kyr B.P. and ending at 11.1 kyr B.P. during which time sea level rose 14 ± 2 m and rates of sea level rise reached 40 mm yr-1. We propose that MWP-1B is the direct albeit lagged response of the Northern Hemisphere ice sheets to the rapid warming marking the end of the Younger Dryas coinciding with rapid warming in the circum-North Atlantic region and the polar front shift from its zonal to meridional position 11.65 kyr B.P. As predicted by glaciological models, the ice sheet response to rapid North Atlantic warming was lagged by 400 years due to the thermal inertia of large ice sheets. The regional circum-North Atlantic Younger Dryas climate event is elevated to a global response through sea level changes, starting with the global slowdown in sea level rise during the Younger Dryas and culminating with MWP-1B. No meltwater pulses are evident at the initiation of the Younger Dryas climate event as is often speculated.

  14. Distribution and abundance of elkhorn coral, Acropora palmata, and prevalence of white-band disease at Buck Island Reef National Monument, St. Croix, US Virgin Islands

    USGS Publications Warehouse

    Mayor, P.A.; Rogers, C.S.; Hillis-Starr, Z.-M.

    2006-01-01

    In the 1970s and 1980s elkhorn coral, Acropora palmata, declined dramatically throughout the Caribbean primarily due to white-band disease (WBD). In 2005, elkhorn coral was proposed for listing as threatened under the US Endangered Species Act. WBD was first documented at Buck Island Reef National Monument (BIRNM). Together with hurricanes WBD reduced live elkhorn coral coverage by probably over 90%. In the past decade some recovery has been observed at BIRNM. This study assessed the distribution and abundance of elkhorn coral and estimated the prevalence of WBD at the monument. Within an area of 795 ha, we estimated 97,232-134,371 (95% confidence limits) elkhorn coral colonies with any dimension of connected live tissue greater than one meter, about 3% of which were infected by WBD. Despite some recovery, the elkhorn coral density remains low and WBD may continue to present a threat to the elkhorn coral population. ?? Springer-Verlag 2006.

  15. Distribution and abundance of elkhorn coral, Acropora palmata, and prevalence of white-band disease at Buck Island Reef National Monument, St. Croix, US Virgin Islands

    NASA Astrophysics Data System (ADS)

    Mayor, Philippe A.; Rogers, Caroline S.; Hillis-Starr, Zandy M.

    2006-05-01

    In the 1970s and 1980s elkhorn coral, Acropora palmata, declined dramatically throughout the Caribbean primarily due to white-band disease (WBD). In 2005, elkhorn coral was proposed for listing as threatened under the US Endangered Species Act. WBD was first documented at Buck Island Reef National Monument (BIRNM). Together with hurricanes WBD reduced live elkhorn coral coverage by probably over 90%. In the past decade some recovery has been observed at BIRNM. This study assessed the distribution and abundance of elkhorn coral and estimated the prevalence of WBD at the monument. Within an area of 795 ha, we estimated 97,232 134,371 (95% confidence limits) elkhorn coral colonies with any dimension of connected live tissue greater than one meter, about 3% of which were infected by WBD. Despite some recovery, the elkhorn coral density remains low and WBD may continue to present a threat to the elkhorn coral population.

  16. Evaluating Patterns of a White-Band Disease (WBD) Outbreak in Acropora palmata Using Spatial Analysis: A Comparison of Transect and Colony Clustering

    PubMed Central

    Lentz, Jennifer A.; Blackburn, Jason K.; Curtis, Andrew J.

    2011-01-01

    Background Despite being one of the first documented, there is little known of the causative agent or environmental stressors that promote white-band disease (WBD), a major disease of Caribbean Acropora palmata. Likewise, there is little known about the spatiality of outbreaks. We examined the spatial patterns of WBD during a 2004 outbreak at Buck Island Reef National Monument in the US Virgin Islands. Methodology/Principal Findings Ripley's K statistic was used to measure spatial dependence of WBD across scales. Localized clusters of WBD were identified using the DMAP spatial filtering technique. Statistics were calculated for colony- (number of A. palmata colonies with and without WBD within each transect) and transect-level (presence/absence of WBD within transects) data to evaluate differences in spatial patterns at each resolution of coral sampling. The Ripley's K plots suggest WBD does cluster within the study area, and approached statistical significance (p = 0.1) at spatial scales of 1100 m or less. Comparisons of DMAP results suggest the transect-level overestimated the prevalence and spatial extent of the outbreak. In contrast, more realistic prevalence estimates and spatial patterns were found by weighting each transect by the number of individual A. palmata colonies with and without WBD. Conclusions As the search for causation continues, surveillance and proper documentation of the spatial patterns may inform etiology, and at the same time assist reef managers in allocating resources to tracking the disease. Our results indicate that the spatial scale of data collected can drastically affect the calculation of prevalence and spatial distribution of WBD outbreaks. Specifically, we illustrate that higher resolution sampling resulted in more realistic disease estimates. This should assist in selecting appropriate sampling designs for future outbreak investigations. The spatial techniques used here can be used to facilitate other coral disease studies

  17. Coral Diseases Following Massive Bleaching in 2005 Cause 60 Percent Decline in Coral Cover and Mortality of the Threatened Species, Acropora Palmata, on Reefs in the U.S. Virgin Islands

    USGS Publications Warehouse

    Rogers, Caroline S.

    2008-01-01

    Record-high seawater temperatures and calm seas in the summer of 2005 led to the most severe coral bleaching (greater than 90 percent bleached coral cover) ever observed in the U.S. Virgin Islands (USVI) (figs. 1 and 2). All but a few coral species bleached, including the threatened species, Acropora palmata. Bleaching was seen from the surface to depths over 20 meters.

  18. Skeletal development in Acropora palmata (Lamarck 1816): a scanning electron microscope (SEM) comparison demonstrating similar mechanisms of skeletal extension in axial versus encrusting growth

    NASA Astrophysics Data System (ADS)

    Gladfelter, E. H.

    2007-12-01

    Many Acropora palmata colonies consist of an encrusting basal portion and erect branches. Linear growth of the skeleton results in extension along the substrate (encrusting growth), lengthening of branches (axial growth) and thickening of branches and crust (radial growth). Scanning Electron Microscopy is used to compare the mechanisms of skeletal extension between encrusting growth and axial growth. In encrusting growth, the distal margin of the skeleton lacks corallites (which develop about 1 mm from the edge); in contrast, in axial growth, axial corallites along the branch tip form the distal portion of the skeleton. In both locations, the distal margin of the skeleton consists of a lattice-like structure composed of rods that extend from the body of the skeleton and bars that connect these rods. An actively extending skeleton is characterized by sharply pointed rods and partially developed bars. Distal growth of rods (and formation of bars) is effected by the formation of new sclerodermites. Each sclerodermite begins with the deposition of fusiform crystals (that range in length from 1 to 5 μm). These provide a surface for nucleation and growth of spherulitic tufts, clusters of short (<1 μm long) aragonite needles. The needles that are oriented perpendicular to the axis of the skeletal element (rod or bar), and perpendicular to the overlying calicoblastic epithelium, continue extension to appear on the surface of the skeleton as 10-15 μm wide bundles (of needle tips) called fasciculi. However, some crusts that abut competitors for space have a different morphology of skeletal elements (rods and bars). The distal edge of these crusts terminates in blunt coalescing rods, and bars that are fully formed. Absence of fusiform crystals, lack of sharply pointed rods and bars, and full development of sclerodermites characterize a skeletal region that has ceased, perhaps only temporarily, skeletal extension.

  19. Analysis of complete mitochondrial DNA sequences of three members of the Montastraea annularis coral species complex (Cnidaria, Anthozoa, Scleractinia)

    NASA Astrophysics Data System (ADS)

    Fukami, Hironobu; Knowlton, Nancy

    2005-11-01

    Complete mitochondrial nucleotide sequences of two individuals each of Montastraea annularis, Montastraea faveolata, and Montastraea franksi were determined. Gene composition and order differed substantially from the sea anemone Metridium senile, but were identical to that of the phylogenetically distant coral genus Acropora. However, characteristics of the non-coding regions differed between the two scleractinian genera. Among members of the M. annularis complex, only 25 of 16,134 base pair positions were variable. Sixteen of these occurred in one colony of M. franksi, which (together with additional data) indicates the existence of multiple divergent mitochondrial lineages in this species. Overall, rates of evolution for these mitochondrial genomes were extremely slow (0.03 0.04% per million years based on the fossil record of the M. annularis complex). At higher taxonomic levels, patterns of genetic divergence and synonymous/nonsynonymous substitutions suggest non-neutral and unequal rates of evolution between the two lineages to which Montastraea and Acropora belong.

  20. Reef-scale trends in Florida Acropora spp. abundance and the effects of population enhancement

    PubMed Central

    Kerr, Katryna; Williams, Dana E.

    2016-01-01

    Since the listing of Acropora palmata and A. cervicornis under the US Endangered Species Act in 2006, increasing investments have been made in propagation of listed corals (primarily A. cervicornis, A. palmata to a much lesser extent) in offshore coral nurseries and outplanting cultured fragments to reef habitats. This investment is superimposed over a spatiotemporal patchwork of ongoing disturbances (especially storms, thermal bleaching, and disease) as well as the potential for natural population recovery. In 2014 and 2015, we repeated broad scale (>50 ha), low precision Acropora spp. censuses (i.e., direct observation by snorkelers documented via handheld GPS) originally conducted in appropriate reef habitats during 2005–2007 to evaluate the trajectory of local populations and the effect of population enhancement. Over the decade-long study, A. palmata showed a cumulative proportional decline of 0.4 –0.7x in colony density across all sites, despite very low levels of outplanting at some sites. A. cervicornis showed similar proportional declines at sites without outplanting. In contrast, sites that received A. cervicornis outplants showed a dramatic increase in density (over 13x). Indeed, change in A. cervicornis colony density was significantly positively correlated with cumulative numbers of outplants across sites. This study documents a substantive reef-scale benefit of Acropora spp. population enhancement in the Florida Keys, when performed at adequate levels, against a backdrop of ongoing population decline. PMID:27703862

  1. Acropora corals in Florida: status, trends, conservation, and prospects for recovery

    USGS Publications Warehouse

    Miller, Margaret W.; Jaap, Walt C.; Chiappone, Mark; Vargas-Angel, Bernardo; Keller, Brian; Aronson, Richard B.; Shinn, Eugene A.; Bruckner, Andrew W.

    2003-01-01

    Despite representing the northern extent of Acropora spp. in the Caribbean, most of the Florida reef line from Palm Beach through the Keys was built by these species. Climatic factors appear to have bee important agents of Acropora loss within historic (century) time frames. In the recent past (1980-present), available quantitative evidence suggests dramatic declines occurred in A. cervicornis first (late 70's to 84) with collapse of A. palmata occuring later (1981-86). However, recent monitoring studies (1996-2001) show continued decline of remnant populations of A. palmata. Current trends in A. cervicornis in the Florida Keys are hard to assess given its exceedingly low abundance, except in Broward County, FL where recently discovered A. cervicornis thickets are thriving. While the State of Florida recognizes A. palmata and A. cervicornis as endangered species (Deyrup and Franz 1994), this designation carries no management implications. The current management plan of the FKNMS provides many strategies for coral conservation, among them minimizing the threat of vessel groundings and anchor damage, and prohibitions on collection, touching, and damage from fishery and recreational users. Although Acropopra spp. are not explicitly given any special consideration, they are implicitly by Santuary management. Restoration approaches undertaken in the Florida Keys include rescue of fragments damaged by groudings and experimental work to culture broadcast-spawned larvae to re-seed natural substrates. Neither of these efforts have yet realized full success.

  2. 50 CFR 226.216 - Critical habitat for elkhorn (Acropora palmata) and staghorn (A. cervicornis) corals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... three specific areas of the Atlantic Ocean and Caribbean Sea offshore of the U.S. Territories of Puerto... shoreward boundary is the line of mean low water (MLW; 33 CFR 2.20). Within these boundaries, discrete areas... West, Monroe County; then follows the MLW line, the SAFMC boundary (see 50 CFR 600.105(c)), and...

  3. 50 CFR 226.216 - Critical habitat for elkhorn (Acropora palmata) and staghorn (A. cervicornis) corals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... three specific areas of the Atlantic Ocean and Caribbean Sea offshore of the U.S. Territories of Puerto... shoreward boundary is the line of mean low water (MLW; 33 CFR 2.20). Within these boundaries, discrete areas... West, Monroe County; then follows the MLW line, the SAFMC boundary (see 50 CFR 600.105(c)), and...

  4. 50 CFR 226.216 - Critical habitat for elkhorn (Acropora palmata) and staghorn (A. cervicornis) corals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... three specific areas of the Atlantic Ocean and Caribbean Sea offshore of the U.S. Territories of Puerto... shoreward boundary is the line of mean low water (MLW; 33 CFR 2.20). Within these boundaries, discrete areas..., Monroe County; then follows the MLW line, the SAFMC boundary (see 50 CFR 600.105(c)), and the...

  5. 50 CFR 226.216 - Critical habitat for elkhorn (Acropora palmata) and staghorn (A. cervicornis) corals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... three specific areas of the Atlantic Ocean and Caribbean Sea offshore of the U.S. Territories of Puerto... shoreward boundary is the line of mean low water (MLW; 33 CFR 2.20). Within these boundaries, discrete areas... West, Monroe County; then follows the MLW line, the SAFMC boundary (see 50 CFR 600.105(c)), and...

  6. 50 CFR 226.216 - Critical habitat for elkhorn (Acropora palmata) and staghorn (A. cervicornis) corals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... three specific areas of the Atlantic Ocean and Caribbean Sea offshore of the U.S. Territories of Puerto... shoreward boundary is the line of mean low water (MLW; 33 CFR 2.20). Within these boundaries, discrete areas..., Monroe County; then follows the MLW line, the SAFMC boundary (see 50 CFR 600.105(c)), and the...

  7. Predicting the distribution of Montastraea reefs using wave exposure

    NASA Astrophysics Data System (ADS)

    Chollett, I.; Mumby, P. J.

    2012-06-01

    In the Caribbean region, forereef habitats dominated by Montastraea spp. have the highest biodiversity and support the largest number of ecosystem processes and services. Here we show that the distribution of this species-rich habitat can be explained by one environmental predictor: wave exposure. The relationship between wave exposure and the occurrence of Montastraea reefs was modelled using logistic regression for reefs throughout the Belize Barrier Reef, one of the largest and most topographically complex systems in the region. The model was able to predict correctly the occurrence of Montastraea reefs with an accuracy of 81%. Consistent with historical qualitative patterns, the distribution of Montastraea reefs is constrained in environments of high exposure. This pattern is likely to be driven by high rates of chronic sediment scour that constrain recruitment. The wide range of wave exposure conditions used to parameterize the model in Belize suggest that it should be transferable throughout much of the Caribbean region, constituting a fast and inexpensive alternative to traditional habitat mapping and complementing global efforts to map reef extent.

  8. Taxonomy and life history of the Acropora-eating flatworm Amakusaplana acroporae nov. sp. (Polycladida: Prosthiostomidae)

    NASA Astrophysics Data System (ADS)

    Rawlinson, K. A.; Gillis, J. A.; Billings, R. E.; Borneman, E. H.

    2011-09-01

    Efforts to culture and conserve acroporid corals in aquaria have led to the discovery of a corallivorous polyclad flatworm (known as AEFW - Acropora-eating flatworm), which, if not removed, can eat entire colonies. Live observations of the AEFW, whole mounts, serial histological sections and comparison of 28S rDNA sequences with other polyclads reveal that this is a new species belonging to the family Prosthiostomidae Lang, 1884 and previously monospecific genus Amakusaplana (Kato 1938). Amakusaplana acroporae is distinguished from Amakusaplana ohshimai by a different arrangement and number of eyes, a large seminal vesicle and dorsoventrally compressed shell gland pouch. Typical of the genus, A. acroporae, lacks a ventral sucker and has a small notch at the midline of the anterior margin. Nematocysts and a Symbiodinium sp. of dinoflagellate from the coral are abundantly distributed in the gut and parenchyma. Individual adults lay multiple egg batches on the coral skeleton, each egg batch has 20-26 egg capsules, and each capsule contains between 3-7 embryos. Embryonic development takes approximately 21 days, during which time characteristics of a pelagic life stage (lobes and ciliary tufts) develop but are lost before hatching. The hatchling is capable of swimming but settles to the benthos quickly, and no zooxanthellae were observed in the animal at this stage. We suggest that intracapsular metamorphosis limits the dispersal potential of hatchlings and promotes recruitment of offspring into the natal habitat. The evolutionary and ecological significance of retaining lobes and ciliary tufts in the embryo are discussed. Camouflage, high fecundity and possible dispersal dimorphisms probably explain how Amakusaplana acroporae can cause Acropora sp. mortality in aquaria where natural predators may be absent.

  9. Genetic Signature of Resistance to White Band Disease in the Caribbean Staghorn Coral Acropora cervicornis.

    PubMed

    Libro, Silvia; Vollmer, Steven V

    2016-01-01

    Coral reefs are declining worldwide due to multiple factors including rising sea surface temperature, ocean acidification, and disease outbreaks. Over the last 30 years, White Band Disease (WBD) alone has killed up to 95% of the Caribbean`s dominant shallow-water corals--the staghorn coral Acropora cervicornis and the elkhorn coral A. palmata. Both corals are now listed on the US Endangered Species Act, and while their recovery has been slow, recent transmission surveys indicate that more than 5% of staghorn corals are disease resistant. Here we compared transcriptome-wide gene expression between resistant and susceptible staghorn corals exposed to WBD using in situ transmission assays. We identified constitutive gene expression differences underlying disease resistance that are independent from the immune response associated with disease exposure. Genes involved in RNA interference-mediated gene silencing, including Argonaute were up-regulated in resistant corals, whereas heat shock proteins (HSPs) were down-regulated. Up-regulation of Argonaute proteins indicates that post-transcriptional gene silencing plays a key, but previously unsuspected role in coral immunity and disease resistance. Constitutive expression of HSPs has been linked to thermal resilience in other Acropora corals, suggesting that the down-regulation of HSPs in disease resistant staghorn corals may confer a dual benefit of thermal resilience. PMID:26784329

  10. Genetic Signature of Resistance to White Band Disease in the Caribbean Staghorn Coral Acropora cervicornis.

    PubMed

    Libro, Silvia; Vollmer, Steven V

    2016-01-01

    Coral reefs are declining worldwide due to multiple factors including rising sea surface temperature, ocean acidification, and disease outbreaks. Over the last 30 years, White Band Disease (WBD) alone has killed up to 95% of the Caribbean`s dominant shallow-water corals--the staghorn coral Acropora cervicornis and the elkhorn coral A. palmata. Both corals are now listed on the US Endangered Species Act, and while their recovery has been slow, recent transmission surveys indicate that more than 5% of staghorn corals are disease resistant. Here we compared transcriptome-wide gene expression between resistant and susceptible staghorn corals exposed to WBD using in situ transmission assays. We identified constitutive gene expression differences underlying disease resistance that are independent from the immune response associated with disease exposure. Genes involved in RNA interference-mediated gene silencing, including Argonaute were up-regulated in resistant corals, whereas heat shock proteins (HSPs) were down-regulated. Up-regulation of Argonaute proteins indicates that post-transcriptional gene silencing plays a key, but previously unsuspected role in coral immunity and disease resistance. Constitutive expression of HSPs has been linked to thermal resilience in other Acropora corals, suggesting that the down-regulation of HSPs in disease resistant staghorn corals may confer a dual benefit of thermal resilience.

  11. Genetic Signature of Resistance to White Band Disease in the Caribbean Staghorn Coral Acropora cervicornis

    PubMed Central

    Libro, Silvia; Vollmer, Steven V.

    2016-01-01

    Coral reefs are declining worldwide due to multiple factors including rising sea surface temperature, ocean acidification, and disease outbreaks. Over the last 30 years, White Band Disease (WBD) alone has killed up to 95% of the Caribbean`s dominant shallow-water corals—the staghorn coral Acropora cervicornis and the elkhorn coral A. palmata. Both corals are now listed on the US Endangered Species Act, and while their recovery has been slow, recent transmission surveys indicate that more than 5% of staghorn corals are disease resistant. Here we compared transcriptome-wide gene expression between resistant and susceptible staghorn corals exposed to WBD using in situ transmission assays. We identified constitutive gene expression differences underlying disease resistance that are independent from the immune response associated with disease exposure. Genes involved in RNA interference-mediated gene silencing, including Argonaute were up-regulated in resistant corals, whereas heat shock proteins (HSPs) were down-regulated. Up-regulation of Argonaute proteins indicates that post-transcriptional gene silencing plays a key, but previously unsuspected role in coral immunity and disease resistance. Constitutive expression of HSPs has been linked to thermal resilience in other Acropora corals, suggesting that the down-regulation of HSPs in disease resistant staghorn corals may confer a dual benefit of thermal resilience. PMID:26784329

  12. Genetic Diversity and Connectivity in the Threatened Staghorn Coral (Acropora cervicornis) in Florida

    PubMed Central

    Hemond, Elizabeth M.; Vollmer, Steven V.

    2010-01-01

    Over the past three decades, populations of the dominant shallow water Caribbean corals, Acropora cervicornis and A. palmata, have been devastated by white-band disease (WBD), resulting in the listing of both species as threatened under the U.S. Endangered Species Act. A key to conserving these threatened corals is understanding how their populations are genetically interconnected throughout the greater Caribbean. Genetic research has demonstrated that gene flow is regionally restricted across the Caribbean in both species. Yet, despite being an important site of coral reef research, little genetic data has been available for the Florida Acropora, especially for the staghorn coral, A. cervicornis. In this study, we present new mitochondrial DNA sequence data from 52 A. cervicornis individuals from 22 sites spread across the upper and lower Florida Keys, which suggest that Florida's A. cervicornis populations are highly genetically interconnected (FST = −0.081). Comparison between Florida and existing mtDNA data from six regional Caribbean populations indicates that Florida possesses high levels of standing genetic diversity (h = 0.824) relative to the rest of the greater Caribbean (h = 0.701±0.043). We find that the contemporary level of gene flow across the greater Caribbean, including Florida, is restricted ( = 0.117), but evidence from shared haplotypes suggests the Western Caribbean has historically been a source of genetic variation for Florida. Despite the current patchiness of A. cervicornis in Florida, the relatively high genetic diversity and connectivity within Florida suggest that this population may have sufficient genetic variation to be viable and resilient to environmental perturbation and disease. Limited genetic exchange across regional populations of the greater Caribbean, including Florida, indicates that conservation efforts for A. cervicornis should focus on maintaining and managing populations locally rather than relying on

  13. Effect of shading by the table coral Acropora Hyacinthus on understory corals. [Acropora; Pocillopora

    SciTech Connect

    Stimson, J.

    1985-02-01

    Field surveys at Enewetak Atoll, Marshall Islands, show that coral density and diversity is much lower beneath Acropora table corals than in adjacent unshaded areas. Additionally, the understory community is predominantly composed of massive and encrusting species, while branching Acropora and Pocillopora predominate in unshaded areas. Results of experiments in which coral fragments were transferred to the shade of table Acropora and to adjacent unshaded areas show that shading slows the growth and leads to higher mortality of branching species, while massive and encrusting species are unaffected. Light measurements made beneath table Acropora show that illumination and irradiance values fall to levels at which most hermatypic corals do not occur. The fast-growing but fragile table Acropora are abundant in a wide variety of atoll habitats and grow rapidly to form a canopy approx. = 50 cm above the substrate. However, table Acropora also have high mortality rates, so that there is continuous production of unshaded areas. The growth and death of tables thus create local disturbances, and the resulting patchwork of recently shaded and unshaded areas may enhance coral diversity in areas of high coral cover.

  14. Reproducibility of geochemical and climatic signals in the Atlantic coral Montastraea faveolata

    USGS Publications Warehouse

    Smith, Joseph M.; Quinn, T.M.; Helmle, K.P.; Halley, R.B.

    2006-01-01

    Monthly resolved, 41-year-long stable isotopic and elemental ratio time series were generated from two separate heads of Montastraea faveolata from Looe Key, Florida, to assess the fidelity of using geochemical variations in Montastraea, the dominant reef-building coral of the Atlantic, to reconstruct sea surface environmental conditions at this site. The stable isotope time series of the two corals replicate well; mean values of ??18O and ??13C are indistinguishable between cores (compare 0.70??? versus 0.68??? for ??13C and -3.90??? versus - 3.94??? for ??18O). Mean values from the Sr/Ca time series differ by 0.037 mmol/mol, which is outside of analytical error and indicates that nonenvironmental factors are influencing the coral Sr/ Ca records at Looe Key. We have generated significant ?? 18O-sea surface temperature (SST) (R = -0.84) and Sr/ Ca-SST (R = -0.86) calibration equations at Looe Key; however, these equations are different from previously published equations for Montastraea. Variations in growth parameters or kinetic effects are not sufficient to explain either the observed differences in the mean offset between Sr/Ca time series or the disagreement between previous calibrations and our calculated ??18O-SST and Sr/Ca-SST relationships. Calibration differences are most likely due to variations in seawater chemistry in the continentally influenced waters at Looe Key. Additional geochemical replication studies of Montastraea are needed and should include multiple coral heads from open ocean localities complemented whenever possible by seawater chemistry determinations. Copyright 2006 by the American Geophysical Union.

  15. Examination of the Montastraea annularis Species Complex (Cnidaria: Scleractinia) Using ITS and COI Sequences.

    PubMed

    Medina; Weil; Szmant

    1999-01-01

    : The Caribbean coral Montastraea annularis has recently been proposed to be a complex of at least three sibling species. To test the validity of this proposal, we sequenced the ITS region of the nuclear ribosomal RNA gene family (ITS-1, 5.8S, and ITS-2), and a portion of the mitochondrial DNA gene cytochrome c oxidase subunit I (COI) from the three proposed species (M. annularis, M. faveolata, and M. franksi) from Florida reefs. The ITS fragment was 665 nucleotides long and had 19 variable sites, of which 6 were parsimony-informative sites. None of these sites was fixed within the proposed species. The COI fragment was 658 nucleotides long with only two sites variable in one individual. Thus, under both the biological species concept and the phylogenetic species concept, the molecular evidence gathered in this study indicates the Montastraea annularis species complex to be a single evolutionary entity as opposed to three distinct species. The three proposed Montastraea species can interbreed, ruling out prezygotic barriers to gene flow (biological species concept), and the criterion of monophyly is not satisfied if hybridization is occurring among taxa (phylogenetic species concept).

  16. Sibling species in Montastraea annularis, coral bleaching, and the coral climate record

    SciTech Connect

    Knowlton, N.; Weil, E.; Weigt, L.A.; Guzman, H.M. )

    1992-01-17

    Measures of growth and skeletal isotopic ratios in the Caribbean coral Montastraea annularis are fundamental to many studies of paleoceanography, environmental degradation, and global climate change. This taxon is shown to consist of at least three sibling species in shallow water. The two most commonly studied of these show highly significant differences in growth rate and oxygen isotopic ratios, parameters routinely used to estimate past climatic conditions; unusual coloration in the third may have confused research on coral bleaching. Interpretation or comparison of past and current studies can be jeopardized by ignoring these species boundaries.

  17. A new record of the late Pleistocene coral Pocillopora palmata from the Dry Tortugas, Florida reef tract, USA

    USGS Publications Warehouse

    Toth, Lauren T.; Kuffner, Ilsa B.; Cheng, Hai; Edwards, R. Lawrence

    2015-01-01

    Pocilloporid corals dominated shallow-water environments in the Caribbean during much of the Cenozoic; however, the regional diversity of this family declined over the last 15 My, culminating with the extinction of its final member, Pocillopora palmata, during the latest Pleistocene. Here we present a new record of P. palmata from Dry Tortugas National Park in the Florida Keys and infer its likely age. Although most existing records of P. palmata are from the sub-aerial reef deposits of MIS5e (∼ 125 ka), the presently submerged reef in the Dry Tortugas was too deep (> 18 m) during this period to support significant reef growth. In contrast, the maximum water depth during MIS5a (∼ 82 ka) was only ∼ 5.6 m, which would have been ideal for P. palmata. Diagenetic alteration prevented direct dating of the samples; however, the similarity between the depths of the Pleistocene bedrock in the Dry Tortugas and other reefs in the Florida Keys, which have been previously dated to MIS5a, support the conclusion that P. palmata likely grew in the Dry Tortugas during this period. Our study provides important new information on the history of P. palmata, but it also highlights the vital need for more comprehensive studies of the Quaternary history of Caribbean reef development. With modern reef degradation already driving yet another restructuring of Caribbean coral assemblages, insights from past extinctions may prove critical in determining the prognosis of Caribbean reefs in the future.

  18. Efficient production of succinic acid from Palmaria palmata hydrolysate by metabolically engineered Escherichia coli.

    PubMed

    Olajuyin, Ayobami Matthew; Yang, Maohua; Liu, Yilan; Mu, Tingzhen; Tian, Jiangnan; Adaramoye, Oluwatosin Adekunle; Xing, Jianmin

    2016-08-01

    Succinic acid, a C4 dicarboxylic acid is used in many fields such as food, agriculture, pharmaceutical and polymer industries. In this study, microbial production of succinic acid from Palmaria palmata was investigated for the first time. In engineered Escherichia coli KLPPP, lactate dehydrogenase, pyruvate formate lyase, phosphotransacetylase-acetate kinase and pyruvate oxidase genes were deleted while phosphoenolpyruvate carboxykinase was overexpressed. The recombinant exhibited higher molar yield of succinic acid on galactose (1.20±0.02mol/mol) than glucose (0.48±0.03mol/mol). The concentration and molar yield of succinic acid were 22.40±0.12g/L and 1.13±0.02mol/mol total sugar respectively after 72h dual phase fermentation from P. palmata hydrolysate which composed of glucose (12.57±0.17g/L) and galactose (18.03±0.10g/L). The results demonstrate that P. palmata red macroalgae biomass represents a novel and an economically alternative feedstock for biochemicals production. PMID:27203224

  19. Aposematic coloration does not deter corallivory by fish on the coral Montastraea cavernosa

    NASA Astrophysics Data System (ADS)

    Jarett, J. K.; Gochfeld, D. J.; Lesser, M. P.

    2016-09-01

    Predation on corals by visual predators is a significant source of partial or total mortality on coral reefs, and corals have evolved strategies, including chemical defenses, to deter predation. One mechanism that organisms use to communicate the presence of chemical defenses is aposematic coloration, or the display of bright coloration as a warning to visual predators such as fish. Corals exhibit multiple colors, and it has been hypothesized that one role for this variability in coloration is as an aposematic warning of adverse palatability. Here, we test green and orange color morphs of the Caribbean coral Montastraea cavernosa for the presence of chemical defenses and whether their differences in coloration elicited different feeding responses. While M. cavernosa is chemically defended, there is no difference in feeding deterrence between color morphs; thus, the different color morphs of this coral species do not appear to represent an example of aposematic coloration.

  20. Life on the edge: corals in mangroves and climate change

    USGS Publications Warehouse

    Rogers, Caroline S.; Herlan, James J.

    2012-01-01

    Coral diseases have played a major role in the degradation of coral reefs in the Caribbean, including those in the US Virgin Islands (USVI). In 2005, bleaching affected reefs throughout the Caribbean, and was especially severe on USVI reefs. Some corals began to regain their color as water temperatures cooled, but an outbreak of disease (primarily white plague) led to losses of over 60% of the total live coral cover. Montastraea annularis, the most abundant coral, was disproportionately affected, and decreased in relative abundance. The threatened species Acropora palmata bleached for the first time on record in the USVI but suffered less bleaching and less mortality from disease than M. annularis. Acropora palmata and M. annularis are the two most significant species in the USVI because of their structural role in the architecture of the reefs, the large size of their colonies, and their complex morphology. The future of the USVI reefs depends largely on their fate. Acropora palmata is more likely to recover than M. annularis for many reasons, including its faster growth rate, and its lower vulnerability to bleaching and disease.

  1. White Band Disease transmission in the threatened coral, Acropora cervicornis

    PubMed Central

    Gignoux-Wolfsohn, S. A.; Marks, Christopher J.; Vollmer, Steven V.

    2012-01-01

    The global rise in coral diseases has severely impacted coral reef ecosystems, yet often little is known about these diseases, including how they are transmitted. White Band Disease (WBD), for example, has caused unparalleled declines in live Acropora cover, spreading rapidly throughout the Caribbean by unknown means. Here we test four putative modes of WBD transmission to the staghorn coral Acropora cervicornis: two animal vectors (Coralliophila abbreviata and C. caribaea) and waterborne transmission to intact and injured coral tissues. Using aquarium-based infection experiments, we determine that C. abbreviata, but not C. caribaea, acts as both a vector and reservoir for transmission of the WBD pathogen. We also demonstrate waterborne transmission to injured, but not intact staghorn coral tissues. The combination of transmission by both animal vectors and through the water column helps explain how WBD is spread locally and across the Caribbean. PMID:23150775

  2. Biannual Spawning and Temporal Reproductive Isolation in Acropora Corals.

    PubMed

    Gilmour, James P; Underwood, Jim N; Howells, Emily J; Gates, Emily; Heyward, Andrew J

    2016-01-01

    Coral spawning on the oceanic reef systems of north-western Australia was recently discovered during autumn and spring, but the degree to which species and particularly colonies participated in one or both of these spawnings was unknown. At the largest of the oceanic reef systems, the participation by colonies in the two discrete spawning events was investigated over three years in 13 species of Acropora corals (n = 1,855 colonies). Seven species spawned during both seasons; five only in autumn and one only in spring. The majority of tagged colonies (n = 218) spawned once a year in the same season, but five colonies from three species spawned during spring and autumn during a single year. Reproductive seasonality was not influenced by spatial variation in habitat conditions, or by Symbiodinium partners in the biannual spawner Acropora tenuis. Colonies of A. tenuis spawning during different seasons separated into two distinct yet cryptic groups, in a bayesian clustering analysis based on multiple microsatellite markers. These groups were associated with a major genetic divergence (G"ST = 0.469), despite evidence of mixed ancestry in a small proportion of individuals. Our results confirm that temporal reproductive isolation is a common feature of Acropora populations at Scott Reef and indicate that spawning season is a genetically determined trait in at least A. tenuis. This reproductive isolation may be punctuated occasionally by interbreeding between genetic groups following favourable environmental conditions, when autumn spawners undergo a second annual gametogenic cycle and spawn during spring. PMID:26963249

  3. Biannual Spawning and Temporal Reproductive Isolation in Acropora Corals

    PubMed Central

    Gilmour, James P.; Underwood, Jim N.; Howells, Emily J.; Gates, Emily; Heyward, Andrew J.

    2016-01-01

    Coral spawning on the oceanic reef systems of north-western Australia was recently discovered during autumn and spring, but the degree to which species and particularly colonies participated in one or both of these spawnings was unknown. At the largest of the oceanic reef systems, the participation by colonies in the two discrete spawning events was investigated over three years in 13 species of Acropora corals (n = 1,855 colonies). Seven species spawned during both seasons; five only in autumn and one only in spring. The majority of tagged colonies (n = 218) spawned once a year in the same season, but five colonies from three species spawned during spring and autumn during a single year. Reproductive seasonality was not influenced by spatial variation in habitat conditions, or by Symbiodinium partners in the biannual spawner Acropora tenuis. Colonies of A. tenuis spawning during different seasons separated into two distinct yet cryptic groups, in a bayesian clustering analysis based on multiple microsatellite markers. These groups were associated with a major genetic divergence (G”ST = 0.469), despite evidence of mixed ancestry in a small proportion of individuals. Our results confirm that temporal reproductive isolation is a common feature of Acropora populations at Scott Reef and indicate that spawning season is a genetically determined trait in at least A. tenuis. This reproductive isolation may be punctuated occasionally by interbreeding between genetic groups following favourable environmental conditions, when autumn spawners undergo a second annual gametogenic cycle and spawn during spring. PMID:26963249

  4. Sexual vs. asexual reproduction in an ecosystem engineer: the massive coral Montastraea annularis.

    PubMed

    Foster, Nicola L; Baums, Iliana B; Mumby, Peter J

    2007-03-01

    1. Long-lived sedentary organisms with a massive morphology are often assumed to utilize a storage effect whereby the persistence of a small group of adults can maintain the population when sexual recruitment fails. However, employing storage effects could prove catastrophic if, under changing climatic conditions, the time period between favourable conditions becomes so prolonged that the population cannot be sustained solely be sexual recruitment. When a species has multiple reproductive options, a rapidly changing environment may favour alternative asexual means of propagation. 2. Here, we revisit the importance of asexual dispersal in a massive coral subject to severe climate-induced disturbance. Montastraea annularis is a major framework-builder of Caribbean coral reefs but its survival is threatened by the increasing cover of macroalgae that prevents settlement of coral larvae. 3. To estimate levels of asexual recruitment within populations of M. annularis, samples from three sites in Honduras were genotyped using four, polymorphic microsatellite loci. 4. A total of 114 unique genets were identified with 8% consisting of two or more colonies and an exceptionally large genet at the third site comprising 14 colonies. 5. At least 70% of multicolony genets observed were formed by physical breakage, consistent with storm damage. 6. Our results reveal that long-lived massive corals can propagate using asexual methods even though sexual strategies predominate.

  5. The effects of a coral disease on the reproductive output of Montastraea faveolata (Scleractinia: Faviidae).

    PubMed

    Borger, Jill L; Colley, Susan

    2010-10-01

    The direct impacts of coral diseases on coral populations have been assessed by quantifying coral tissue loss and colony mortality, but the determination of the indirect effects of diseases, such as disruptions in life history functions (e.g. reproduction, growth and maintenance), are more difficult to ascertain and have been scant. This study involved a comparison of various measures of reproductive output from histological slides of healthy tissue samples of Montastraea faveolata and tissue samples from colonies with white plague (WP) infections in Dominica (West Indies). Although the variability in the reproductive data was high, WP had significant negative impacts on the percentage of reproductive polyps per cm2, the percentage of reproductive mesenteries within a polyp, oocyte quantity per polyp, mean oocyte volume (mm3), and fecundity (oocyte volume per cm2 of tissue). However, these effects were only observed in the tissue directly impacted by the WP disease "band" and were not observed in tissue samples taken 20 cm away from the lesion. Therefore, the effects of a coral disease (WP) on reproductive output are localized and not expressed colony-wide.

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

    PubMed Central

    Barott, Katie L.; Rodriguez-Mueller, Beltran; Youle, Merry; Marhaver, Kristen L.; Vermeij, Mark J. A.; Smith, Jennifer E.; Rohwer, Forest L.

    2012-01-01

    Competition between reef-building corals and benthic algae is of key importance for reef dynamics. These interactions occur on many spatial scales, ranging from chemical to regional. Using microprobes, 16S rDNA pyrosequencing and underwater surveys, we examined the interactions between the reef-building coral Montastraea annularis and four types of benthic algae. The macroalgae Dictyota bartayresiana and Halimeda opuntia, as well as a mixed consortium of turf algae, caused hypoxia on the adjacent coral tissue. Turf algae were also associated with major shifts in the bacterial communities at the interaction zones, including more pathogens and virulence genes. In contrast to turf algae, interactions with crustose coralline algae (CCA) and M. annularis did not appear to be antagonistic at any scale. These zones were not hypoxic, the microbes were not pathogen-like and the abundance of coral–CCA interactions was positively correlated with per cent coral cover. We propose a model in which fleshy algae (i.e. some species of turf and fleshy macroalgae) alter benthic competition dynamics by stimulating bacterial respiration and promoting invasion of virulent bacteria on corals. This gives fleshy algae a competitive advantage over corals when human activities, such as overfishing and eutrophication, remove controls on algal abundance. Together, these results demonstrate the intricate connections and mechanisms that structure coral reefs. PMID:22090385

  7. Population Structure of Montastraea cavernosa on Shallow versus Mesophotic Reefs in Bermuda.

    PubMed

    Goodbody-Gringley, Gretchen; Marchini, Chiara; Chequer, Alex D; Goffredo, Stefano

    2015-01-01

    Mesophotic coral reef ecosystems remain largely unexplored with only limited information available on taxonomic composition, abundance and distribution. Yet, mesophotic reefs may serve as potential refugia for shallow-water species and thus understanding biodiversity, ecology and connectivity of deep reef communities is integral for resource management and conservation. The Caribbean coral, Montastraea cavernosa, is considered a depth generalist and is commonly found at mesophotic depths. We surveyed abundance and size-frequency of M. cavernosa populations at six shallow (10m) and six upper mesophotic (45m) sites in Bermuda and found population structure was depth dependent. The mean surface area of colonies at mesophotic sites was significantly smaller than at shallow sites, suggesting that growth rates and maximum colony surface area are limited on mesophotic reefs. Colony density was significantly higher at mesophotic sites, however, resulting in equal contributions to overall percent cover. Size-frequency distributions between shallow and mesophotic sites were also significantly different with populations at mesophotic reefs skewed towards smaller individuals. Overall, the results of this study provide valuable baseline data on population structure, which indicate that the mesophotic reefs of Bermuda support an established population of M. cavernosa. PMID:26544963

  8. Hurricane-driven patterns of clonality in an ecosystem engineer: the Caribbean coral Montastraea annularis.

    PubMed

    Foster, Nicola L; Baums, Iliana B; Sanchez, Juan A; Paris, Claire B; Chollett, Iliana; Agudelo, Claudia L; Vermeij, Mark J A; Mumby, Peter J

    2013-01-01

    K-selected species with low rates of sexual recruitment may utilise storage effects where low adult mortality allows a number of individuals to persist through time until a favourable recruitment period occurs. Alternative methods of recruitment may become increasingly important for such species if the availability of favourable conditions for sexual recruitment decline under rising anthropogenic disturbance and climate change. Here, we test the hypotheses that asexual dispersal is an integral life history strategy not only in branching corals, as previously reported, but also in a columnar, 'K-selected' coral species, and that its prevalence is driven by the frequency of severe hurricane disturbance. Montastraea annularis is a long-lived major frame-work builder of Caribbean coral reefs but its survival is threatened by the consequences of climate induced disturbance, such as bleaching, ocean acidification and increased prevalence of disease. 700 M. annularis samples from 18 reefs within the Caribbean were genotyped using six polymorphic microsatellite loci. We demonstrate that asexual reproduction occurs at varying frequency across the species-range and significantly contributes to the local abundance of M. annularis, with its contribution increasing in areas with greater hurricane frequency. We tested several competing hypotheses that might explain the observed pattern of genotypic diversity. 64% of the variation in genotypic diversity among the sites was explained by hurricane incidence and reef slope, demonstrating that large-scale disturbances combine with local habitat characteristics to shape the balance between sexual and asexual reproduction in populations of M. annularis.

  9. Hurricane-Driven Patterns of Clonality in an Ecosystem Engineer: The Caribbean Coral Montastraea annularis

    PubMed Central

    Foster, Nicola L.; Baums, Iliana B.; Sanchez, Juan A.; Paris, Claire B.; Chollett, Iliana; Agudelo, Claudia L.; Vermeij, Mark J. A.; Mumby, Peter J.

    2013-01-01

    K-selected species with low rates of sexual recruitment may utilise storage effects where low adult mortality allows a number of individuals to persist through time until a favourable recruitment period occurs. Alternative methods of recruitment may become increasingly important for such species if the availability of favourable conditions for sexual recruitment decline under rising anthropogenic disturbance and climate change. Here, we test the hypotheses that asexual dispersal is an integral life history strategy not only in branching corals, as previously reported, but also in a columnar, ‘K-selected’ coral species, and that its prevalence is driven by the frequency of severe hurricane disturbance. Montastraea annularis is a long-lived major frame-work builder of Caribbean coral reefs but its survival is threatened by the consequences of climate induced disturbance, such as bleaching, ocean acidification and increased prevalence of disease. 700 M. annularis samples from 18 reefs within the Caribbean were genotyped using six polymorphic microsatellite loci. We demonstrate that asexual reproduction occurs at varying frequency across the species-range and significantly contributes to the local abundance of M. annularis, with its contribution increasing in areas with greater hurricane frequency. We tested several competing hypotheses that might explain the observed pattern of genotypic diversity. 64% of the variation in genotypic diversity among the sites was explained by hurricane incidence and reef slope, demonstrating that large-scale disturbances combine with local habitat characteristics to shape the balance between sexual and asexual reproduction in populations of M. annularis. PMID:23308185

  10. Population Structure of Montastraea cavernosa on Shallow versus Mesophotic Reefs in Bermuda

    PubMed Central

    Goodbody-Gringley, Gretchen; Marchini, Chiara; Chequer, Alex D.; Goffredo, Stefano

    2015-01-01

    Mesophotic coral reef ecosystems remain largely unexplored with only limited information available on taxonomic composition, abundance and distribution. Yet, mesophotic reefs may serve as potential refugia for shallow-water species and thus understanding biodiversity, ecology and connectivity of deep reef communities is integral for resource management and conservation. The Caribbean coral, Montastraea cavernosa, is considered a depth generalist and is commonly found at mesophotic depths. We surveyed abundance and size-frequency of M. cavernosa populations at six shallow (10m) and six upper mesophotic (45m) sites in Bermuda and found population structure was depth dependent. The mean surface area of colonies at mesophotic sites was significantly smaller than at shallow sites, suggesting that growth rates and maximum colony surface area are limited on mesophotic reefs. Colony density was significantly higher at mesophotic sites, however, resulting in equal contributions to overall percent cover. Size-frequency distributions between shallow and mesophotic sites were also significantly different with populations at mesophotic reefs skewed towards smaller individuals. Overall, the results of this study provide valuable baseline data on population structure, which indicate that the mesophotic reefs of Bermuda support an established population of M. cavernosa. PMID:26544963

  11. Differential gene expression during thermal stress and bleaching in the Caribbean coral Montastraea faveolata.

    PubMed

    DeSalvo, M K; Voolstra, C R; Sunagawa, S; Schwarz, J A; Stillman, J H; Coffroth, M A; Szmant, A M; Medina, M

    2008-09-01

    The declining health of coral reefs worldwide is likely to intensify in response to continued anthropogenic disturbance from coastal development, pollution, and climate change. In response to these stresses, reef-building corals may exhibit bleaching, which marks the breakdown in symbiosis between coral and zooxanthellae. Mass coral bleaching due to elevated water temperature can devastate coral reefs on a large geographical scale. In order to understand the molecular and cellular basis of bleaching in corals, we have measured gene expression changes associated with thermal stress and bleaching using a complementary DNA microarray containing 1310 genes of the Caribbean coral Montastraea faveolata. In a first experiment, we identified differentially expressed genes by comparing experimentally bleached M. faveolata fragments to control non-heat-stressed fragments. In a second experiment, we identified differentially expressed genes during a time course experiment with four time points across 9 days. Results suggest that thermal stress and bleaching in M. faveolata affect the following processes: oxidative stress, Ca(2+) homeostasis, cytoskeletal organization, cell death, calcification, metabolism, protein synthesis, heat shock protein activity, and transposon activity. These results represent the first medium-scale transcriptomic study focused on revealing the cellular foundation of thermal stress-induced coral bleaching. We postulate that oxidative stress in thermal-stressed corals causes a disruption of Ca(2+) homeostasis, which in turn leads to cytoskeletal and cell adhesion changes, decreased calcification, and the initiation of cell death via apoptosis and necrosis.

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

    PubMed

    Barott, Katie L; Rodriguez-Mueller, Beltran; Youle, Merry; Marhaver, Kristen L; Vermeij, Mark J A; Smith, Jennifer E; Rohwer, Forest L

    2012-04-22

    Competition between reef-building corals and benthic algae is of key importance for reef dynamics. These interactions occur on many spatial scales, ranging from chemical to regional. Using microprobes, 16S rDNA pyrosequencing and underwater surveys, we examined the interactions between the reef-building coral Montastraea annularis and four types of benthic algae. The macroalgae Dictyota bartayresiana and Halimeda opuntia, as well as a mixed consortium of turf algae, caused hypoxia on the adjacent coral tissue. Turf algae were also associated with major shifts in the bacterial communities at the interaction zones, including more pathogens and virulence genes. In contrast to turf algae, interactions with crustose coralline algae (CCA) and M. annularis did not appear to be antagonistic at any scale. These zones were not hypoxic, the microbes were not pathogen-like and the abundance of coral-CCA interactions was positively correlated with per cent coral cover. We propose a model in which fleshy algae (i.e. some species of turf and fleshy macroalgae) alter benthic competition dynamics by stimulating bacterial respiration and promoting invasion of virulent bacteria on corals. This gives fleshy algae a competitive advantage over corals when human activities, such as overfishing and eutrophication, remove controls on algal abundance. Together, these results demonstrate the intricate connections and mechanisms that structure coral reefs.

  13. Population Structure of Montastraea cavernosa on Shallow versus Mesophotic Reefs in Bermuda.

    PubMed

    Goodbody-Gringley, Gretchen; Marchini, Chiara; Chequer, Alex D; Goffredo, Stefano

    2015-01-01

    Mesophotic coral reef ecosystems remain largely unexplored with only limited information available on taxonomic composition, abundance and distribution. Yet, mesophotic reefs may serve as potential refugia for shallow-water species and thus understanding biodiversity, ecology and connectivity of deep reef communities is integral for resource management and conservation. The Caribbean coral, Montastraea cavernosa, is considered a depth generalist and is commonly found at mesophotic depths. We surveyed abundance and size-frequency of M. cavernosa populations at six shallow (10m) and six upper mesophotic (45m) sites in Bermuda and found population structure was depth dependent. The mean surface area of colonies at mesophotic sites was significantly smaller than at shallow sites, suggesting that growth rates and maximum colony surface area are limited on mesophotic reefs. Colony density was significantly higher at mesophotic sites, however, resulting in equal contributions to overall percent cover. Size-frequency distributions between shallow and mesophotic sites were also significantly different with populations at mesophotic reefs skewed towards smaller individuals. Overall, the results of this study provide valuable baseline data on population structure, which indicate that the mesophotic reefs of Bermuda support an established population of M. cavernosa.

  14. Exposure to copper induces oxidative and stress responses and DNA damage in the coral Montastraea franksi.

    PubMed

    Schwarz, J A; Mitchelmore, C L; Jones, R; O'Dea, A; Seymour, S

    2013-04-01

    Copper is a common chemical contaminant in coastal environments, including coral reefs. Ecotoxicological studies have demonstrated that exposure to copper can cause stress and detrimental effects in both host cnidarian and algal symbionts. The objective of this study was to investigate the sublethal effects of copper on the reef-building coral Montastraea franksi, by identifying genes with altered expression in corals exposed to dissolved copper, and by measuring the extent of damage to DNA in response to copper exposure. Corals exposed to 30 μg L(-1) copper for 48 h experienced significant DNA damage and displayed changes in expression patterns of genes that are known to play role cellular and oxidative stress responses. Corals also experienced changes in gene expression of genes that are not already known to play roles in oxidative stress in corals. Our data suggest that these genes may either play roles directly in mediating a stress response, or may be genes acting downstream of the stress response. These include an ETS domain-containing transcription factor related to the ETS1 family of transcription factors, known in mammals to mediate development, disease, and stress response, and two genes that are associated with biomineralization: galaxin, a protein from the organic matrix of the coral skeleton, and a coral-specific gene SCRIP2.

  15. Identification of genome constitutions in Begonia×chungii and its putative parents, B. longifolia and B. palmata, by genomic in situ hybridization (GISH).

    PubMed

    Kono, Yoshiko; Chung, Mei-Chu; Peng, Ching-I

    2012-04-01

    Based mainly on morphological features and geographical distribution, Begonia×chungii (2n=22) was recently reported as a natural hybrid between B. longifolia and B. palmata in Taiwan. This study aims to confirm the hybridity of B.×chungii and to sort out the genome constitutions of its putative parents, using genomic in situ hybridization (GISH). Genomic DNAs of both parental species were used as probes for B.×chungii and the experimental F(1) hybrid, B. palmata×B. longifolia, in GISH analyses. Bicolor-GISH analyses in B.×chungii showed that the 22 chromosomes consisted of six chromosomes hybridized with a probe derived from the B. palmata genome, six with another probe from the B. longifolia genome and the remaining ten with both genomes overlapped. Meanwhile, bicolor-GISH in B. palmata×B. longifolia showed a remarkable similarity to that of B.×chungii. The reciprocal GISH results between B. longifolia and B. palmata were comparable. Our GISH analyses confirmed that B.×chungii is a natural F(1) hybrid between B. longifolia and B. palmata. Genomes of the parental species were shown to be partially homologous, suggesting a derived common ancestral genome in them.

  16. Mechanisms of reproductive isolation among sympatric broadcast-spawning corals of the Montastraea annularis species complex.

    PubMed

    Levitan, Don R; Fukami, Hironobu; Jara, Javier; Kline, David; McGovern, Tamara M; McGhee, Katie E; Swanson, Cheryl A; Knowlton, Nancy

    2004-02-01

    Many coral species spawn simultaneously and have compatible gametes, leading to controversy over the nature of species boundaries and the frequency with which hybridization occurs. Three western Atlantic corals, Montastraea annularis, M. faveolata, and M. franksi, typify this controversy; they all spawn sympatrically on the same evenings after the fall full moons. Here we show, in both Panama and the Bahamas for multiple years, how a variety of mechanisms may act in concert to reproductively isolate all three species. Field studies indicate that M. franksi spawns two hours earlier than the other two species, and the eggs released during this earlier period disperse an average of 500 m by the time the other species spawn. Field measures of fertilization indicate that peak fertilization occurs when spawning synchrony is high and that corals that spawn at the tails of the spawning distributions have greatly reduced fertilization success. Laboratory studies indicate that there is a gametic incompatibility between M. faveolata and the other two species. There are regional differences in the gametic compatibility of M. franksi and M. annularis. In Panama, the two species are completely compatible, whereas in the Bahamas, M. franksi sperm can fertilize M. annularis eggs but the reciprocal cross often fails. Gamete age influences patterns of fertilization, such that very young eggs seem resistant to fertilization and old sperm lose viability after two hours. In sum, the combination of temporal differences in spawning, sperm aging, gamete dispersal and dilution, and gametic incompatibility act in various combinations among the three species, making it unlikely that hybrid fertilization would occur.

  17. Genetic structure in the coral, Montastraea cavernosa: assessing genetic differentiation among and within Mesophotic reefs.

    PubMed

    Brazeau, Daniel A; Lesser, Michael P; Slattery, Marc

    2013-01-01

    Mesophotic coral reefs (30-150 m) have recently received increased attention as a potential source of larvae (e.g., the refugia hypothesis) to repopulate a select subset of the shallow water (<30 m) coral fauna. To test the refugia hypothesis we used highly polymorphic Amplified Fragment Length Polymorphism (AFLP) markers as a means to assess small-scale genetic heterogeneity between geographic locations and across depth clines in the Caribbean coral, Montastraea cavernosa. Zooxanthellae-free DNA extracts of coral samples (N = 105) were analyzed from four depths, shallow (3-10 m), medium (15-25 m), deep (30-50 m) and very deep (60-90 m) from Little Cayman Island (LCI), Lee Stocking Island (LSI), Bahamas and San Salvador (SS), Bahamas which range in distance from 170 to 1,600 km apart. Using AMOVA analysis there were significant differences in ΦST values in pair wise comparisons between LCI and LSI. Among depths at LCI, there was significant genetic differentiation between shallow and medium versus deep and very deep depths in contrast there were no significant differences in ΦST values among depths at LSI. The assignment program AFLPOP, however, correctly assigned 95.7% of the LCI and LSI samples to the depths from which they were collected, differentiating among populations as little as 10 to 20 m in depth from one another. Discriminant function analysis of the data showed significant differentiation among samples when categorized by collection site as well as collection depth. FST outlier analyses identified 2 loci under positive selection and 3 under balancing selection at LCI. At LSI 2 loci were identified, both showing balancing selection. This data shows that adult populations of M. cavernosa separated by depths of tens of meters exhibits significant genetic structure, indicative of low population connectivity among and within sites and are not supplying successful recruits to adjacent coral reefs less than 30 m in depth.

  18. Calcification in bleached and unbleached Montastraea faveolata: evaluating the role of oxygen and glycerol

    NASA Astrophysics Data System (ADS)

    Colombo-Pallotta, M. F.; Rodríguez-Román, A.; Iglesias-Prieto, R.

    2010-12-01

    All reef-building corals are symbiotic with dinoflagellates of the genus Symbiodinium, which influences many aspects of the host’s physiology including calcification. Coral calcification is a biologically controlled process performed by the host that takes place several membranes away from the site of photosynthesis performed by the symbiont. Although it is well established that light accelerates CaCO3 deposition in reef-building corals (commonly referred to as light-enhanced calcification), the complete physiological mechanism behind the process is not fully understood. To better comprehend the coral calcification process, a series of laboratory experiments were conducted in the major Caribbean reef-building species Montastraea faveolata, to evaluate the effect of glycerol addition and/or the super-saturation of oxygen in the seawater. These manipulations were performed in bleached and unbleached corals, to separate the effect of photosynthesis from calcification. The results suggest that under normal physiological conditions, a 42% increase in seawater oxygen concentration promotes a twofold increase in dark-calcification rates relative to controls. On the other hand, the results obtained using bleached corals suggest that glycerol is required, as a metabolic fuel, in addition to an oxygenic environment in a symbiosis that has been disrupted. Also, respiration rates in symbiotic corals that were pre-incubated in light conditions showed a kinetic limitation, whereas corals that were pre-incubated in darkness were oxygen limited, clearly emphasizing the role of oxygen in this regard. These findings indicate that calcification in symbiotic corals is not strictly a “light-enhanced” or “dark-repressed” process, but rather, the products of photosynthesis have a critical role in calcification, which should be viewed as a “photosynthesis-driven” process. The results presented here are discussed in the context of the current knowledge of the coral

  19. Biological Responses of the Coral Montastraea annularis to the Removal of Filamentous Turf Algae

    PubMed Central

    Cetz-Navarro, Neidy P.; Espinoza-Avalos, Julio; Hernández-Arana, Héctor A.; Carricart-Ganivet, Juan P.

    2013-01-01

    Coral reef degradation increases coral interactions with filamentous turf algae (FTA) and macroalgae, which may result in chronic stress for the corals. We evaluated the effects of short (2.5 month) and long (10 month) periods of FTA removal on tissue thickness (TT), zooxanthellae density (ZD), mitotic index (MI), and concentration of chlorophyll a (Chl a) in Montastraea annularis at the beginning and end of gametogenesis. Ramets (individual lobes within a colony) consistently surrounded by FTA and ramets surrounded by crustose coralline algae (CCA) were used as controls. FTA removal reduced coral stress, indicated by increased TT and ZD and lower MI. The measured effects were similar in magnitude for the short and long periods of algal removal. Ramets were more stressed at the end of gametogenesis compared with the beginning, with lower ZD and Chl a cm−2, and higher MI. However, it was not possible to distinguish the stress caused by the presence of FTA from that caused by seasonal changes in seawater temperature. Ramets surrounded by CCA showed less stress in comparison with ramets surrounded by FTA: with higher TT, Chl a cm−2 and ZD, and lower MI values. Coral responses indicated that ramets with FTA suffered the most deleterious effects and contrasted with those measured in ramets surrounded by CCA. According to published studies and our observations, there could be at least six mechanisms associated to FTA in the stress caused to M. annularis by FTA. Owing to the high cover of FTA (in contrast to macroalgae and CCA) in the Caribbean, the chronic stress, the overgrowth and mortality that this functional algal group can cause on M. annularis species complex, a further decline of this important reef-building coral in the Caribbean is expected. PMID:23372774

  20. Growth Dynamics of the Threatened Caribbean Staghorn Coral Acropora cervicornis: Influence of Host Genotype, Symbiont Identity, Colony Size, and Environmental Setting

    PubMed Central

    Lirman, Diego; Schopmeyer, Stephanie; Galvan, Victor; Drury, Crawford; Baker, Andrew C.; Baums, Iliana B.

    2014-01-01

    Background The drastic decline in the abundance of Caribbean acroporid corals (Acropora cervicornis, A. palmata) has prompted the listing of this genus as threatened as well as the development of a regional propagation and restoration program. Using in situ underwater nurseries, we documented the influence of coral genotype and symbiont identity, colony size, and propagation method on the growth and branching patterns of staghorn corals in Florida and the Dominican Republic. Methodology/Principal Findings Individual tracking of> 1700 nursery-grown staghorn fragments and colonies from 37 distinct genotypes (identified using microsatellites) in Florida and the Dominican Republic revealed a significant positive relationship between size and growth, but a decreasing rate of productivity with increasing size. Pruning vigor (enhanced growth after fragmentation) was documented even in colonies that lost 95% of their coral tissue/skeleton, indicating that high productivity can be maintained within nurseries by sequentially fragmenting corals. A significant effect of coral genotype was documented for corals grown in a common-garden setting, with fast-growing genotypes growing up to an order of magnitude faster than slow-growing genotypes. Algal-symbiont identity established using qPCR techniques showed that clade A (likely Symbiodinium A3) was the dominant symbiont type for all coral genotypes, except for one coral genotype in the DR and two in Florida that were dominated by clade C, with A- and C-dominated genotypes having similar growth rates. Conclusion/Significance The threatened Caribbean staghorn coral is capable of extremely fast growth, with annual productivity rates exceeding 5 cm of new coral produced for every cm of existing coral. This species benefits from high fragment survivorship coupled by the pruning vigor experienced by the parent colonies after fragmentation. These life-history characteristics make A. cervicornis a successful candidate nursery species

  1. Changes in spawning time led to the speciation of the broadcast spawning corals Acropora digitifera and the cryptic species Acropora sp. 1 with similar gamete recognition systems

    NASA Astrophysics Data System (ADS)

    Ohki, Shun; Kowalski, Radoslaw K.; Kitanobo, Seiya; Morita, Masaya

    2015-12-01

    Multi-species spawning is reported in the coral genus Acropora, but hybridization in nature rarely occurs because of the incompatibility of gametes and the timing of spawning. However, the evolutionary relationships between gamete compatibility and spawning time are obscure. Investigations of gamete compatibility in sister species that spawn at different times may provide clues to answering this question. Acropora sp. 1 has been defined as a cryptic species of Acropora digitifera, and they are morphologically similar, but spawn in different months, suggesting that they are either a cryptic species or a different species. We examined the morphology and conducted crossing experiments using cryopreserved sperm. The morphologies (branch length, branch width, and outer diameter of axial corallites) of A. digitifera and Acropora sp. 1 differed significantly. A phylogenetic tree of partial Pax- C nuclear sequences from A. digitifera and Acropora sp. 1 shows that they are monophyletic and closely related genetically, based on F ST values and P-distance. These results imply that these two species originated recently from a common ancestor. In addition, cryopreserved sperm from both A. digitifera and Acropora sp. 1 showed bidirectional inter-crossing (cryopreserved sperm of A. digitifera and eggs of Acropora sp. 1 from Sesoko: 32.1 ± 6.7 %, control-conspecific cryopreserved sperm and eggs: 46.1 ± 10.6 %; cryopreserved sperm of Acropora sp. 1 and eggs of A. digitifera from Oku: 63.3 ± 16.6 %, control: 83.6 ± 6.0 %). The results suggest that the gametes of these two species are compatible and that the pre-zygotic isolation mechanism is relaxed because their gametes do not interact. Overall, these two species should be classified as distinct species, and changes in spawning time are related to speciation in a similar gamete recognition system.

  2. Rarity and genetic diversity in Indo–Pacific Acropora corals

    PubMed Central

    Richards, Zoe T; Oppen, Madeleine J H

    2012-01-01

    Among various potential consequences of rarity is genetic erosion. Neutral genetic theory predicts that rare species will have lower genetic diversity than common species. To examine the association between genetic diversity and rarity, variation at eight DNA microsatellite markers was documented for 14 Acropora species that display different patterns of distribution and abundance in the Indo–Pacific Ocean. Our results show that the relationship between rarity and genetic diversity is not a positive linear association because, contrary to expectations, some rare species are genetically diverse and some populations of common species are genetically depleted. Our data suggest that inbreeding is the most likely mechanism of genetic depletion in both rare and common corals, and that hybridization is the most likely explanation for higher than expected levels of genetic diversity in rare species. A significant hypothesis generated from our study with direct conservation implications is that as a group, Acropora corals have lower genetic diversity at neutral microsatellite loci than may be expected from their taxonomic diversity, and this may suggest a heightened susceptibility to environmental change. This hypothesis requires validation based on genetic diversity estimates derived from a large portion of the genome. PMID:22957189

  3. High resistance of Acropora coral gametes facing copper exposure.

    PubMed

    Puisay, Antoine; Pilon, Rosanne; Hédouin, Laetitia

    2015-02-01

    Pollution by heavy metals remains today an important threat to the health of humans and ecosystems, but there is still a paucity of data on the response of early life stages of key organisms. In this context, the present work assessed the fertilization success rate of two Acropora species (A. cytherea and A. pulchra) from the French Polynesia reefs exposed to six increasing copper concentrations in seawater. The two species showed a relatively high tolerance to copper (4h30-EC50 was 69.4 ± 4.8 μg L(-1) and 75.4 ± 6.4 μg L(-1) for A. cytherea and A. pulchra, respectively). As Cu concentration increases, an increasing proportion of deformed embryos was recorded (67.6% and 58.5% for A. cytherea and A. pulchra, respectively, at 220 μg Cu L(-1)). These results demonstrated thus, that high levels of copper could negatively impair the normal fertilization process of coral gametes and therefore alter the renewal of coral populations. Since the two Acropora species investigated in this study displayed a high resistance to copper, these results should be considered in the context of multiple stressors associated with climate change, where rising temperature or ocean acidification may significantly exacerbate copper toxicity.

  4. Effects of temperature, nutrients, organic matter and coral mucus on the survival of the coral pathogen, Serratia marcescens PDL100.

    PubMed

    Looney, Erin E; Sutherland, Kathryn P; Lipp, Erin K

    2010-09-01

    Serratia marcescens is an enteric bacterium that causes white pox disease in elkhorn coral, Acropora palmata; however, it remains unclear if the pathogenic strain has adapted to seawater or if it requires a host or reservoir for survival. To begin to address this fundamental issue, the persistence of strain PDL100 was compared among seawater and coral mucus microcosms. Median survival time across all conditions ranged from a low of 15 h in natural seawater [with a first-order decay constant (k) = -0.173] at 30°C to a maximum of 120 h in glucose-amended A. palmata mucus (k = -0.029) at 30°C. Among seawater and mucus microcosms, median survival time was significantly greater within Siderastrea siderea mucus compared with seawater or mucus of Montastraea faveolata or A. palmata (P < 0.0001). In seawater, the addition of phosphate and especially glucose resulted in significant improvements in survival (P < 0.001), while only the addition of glucose resulted in significant improvement in survival in A. palmata mucus (P < 0.0001). Increasing the temperature of seawater to 35°C resulted in a significantly slower decay than that observed at 30°C (P < 0.0001). The results of this study indicate that PDL100 is not well-adapted to marine water; however, survival can be improved by increasing temperature, the availability of coral mucus from S. siderea and most notably the presence of dissolved organic carbon.

  5. Spatial and size-frequency distribution of Acropora (Cnidaria: Scleractinia) species in Chinchorro Bank, Mexican Caribbean: implications for management

    NASA Astrophysics Data System (ADS)

    Vega-Zepeda, A.; Hernández-Arana, H.; Carricart-Ganivet, J. P.

    2007-09-01

    The Mexican Government decreed Chinchorro Bank reef as a Biosphere Reserve in 1996. The aim of this study was to evaluate the spatial and size-frequency distribution of Acropora spp. in order to provide further knowledge and tools to enhance management. A field survey was conducted, within six regions, to locate and measure Acropora patches in the reef lagoon. Density, colony size and living tissue cover of Acropora colonies were evaluated using the line-intercept transect technique, combining direct observations and video transects. The results showed that Acropora spp. was preferentially distributed in the southern regions; where cover and density were high. Based on these results and considering that Acropora spp. produces landscape heterogeneity, which in turn generates shelter for other species, including some of considerable economic importance, then at least the South East region should be considered as a key area for Acropora species conservation, and should be included in the Chinchorro Bank management plan.

  6. Optimization of dynamic headspace extraction of the edible red algae Palmaria palmata and identification of the volatile components.

    PubMed

    Le Pape, Marie-Annick; Grua-Priol, Joëlle; Prost, Carole; Demaimay, Michel

    2004-02-11

    A new extraction method was applied to the volatile compounds of Palmaria palmata. Dynamic headspace was optimized according to an experimental design, and descriptive sensory analysis and intensity and similarity tests were performed for each extract to assess their respective representativeness. Results showed that extract obtained with crushed algae after a 30 min purge was the most representative. GC-MS analysis was then performed on this extract to identify the volatile components. Seven halogenated compounds, seven aldehydes, two ketones, three alcohols, and four miscellaneous compounds were identified. Among them, halogenated compounds were the most characteristic of red algae, and more particularly, iodoethane and iodopentane, which had yet been found in other seaweeds.

  7. Angiotensin I Converting Enzyme Inhibitory Peptides Derived from Phycobiliproteins of Dulse Palmaria palmata

    PubMed Central

    Furuta, Tomoe; Miyabe, Yoshikatsu; Yasui, Hajime; Kinoshita, Yasunori; Kishimura, Hideki

    2016-01-01

    We examined the inhibitory activity of angiotensin I converting enzyme (ACE) in protein hydrolysates from dulse, Palmaria palmata. The proteins extracted from dulse were mainly composed of phycoerythrin (PE) followed by phycocyanin (PC) and allophycocyanin (APC). The dulse proteins showed slight ACE inhibitory activity, whereas the inhibitory activity was extremely enhanced by thermolysin hydrolysis. The ACE inhibitory activity of hydrolysates was hardly affected by additional pepsin, trypsin and chymotrypsin treatments. Nine ACE inhibitory peptides (YRD, AGGEY, VYRT, VDHY, IKGHY, LKNPG, LDY, LRY, FEQDWAS) were isolated from the hydrolysates by reversed-phase high-performance liquid chromatography (HPLC), and it was demonstrated that the synthetic peptide LRY (IC50: 0.044 μmol) has remarkably high ACE inhibitory activity. Then, we investigated the structural properties of dulse phycobiliproteins to discuss the origin of dulse ACE inhibitory peptides. Each dulse phycobiliprotein possesses α-subunit (Mw: 17,477–17,638) and β-subunit (Mw: 17,455–18,407). The sequences of YRD, AGGEY, VYRT, VDHY, LKNPG and LDY were detected in the primary structure of PE α-subunit, and the LDY also exists in the APC α- and β-subunits. In addition, the LRY sequence was found in the β-subunits of PE, PC and APC. From these results, it was suggested that the dulse ACE inhibitory peptides were derived from phycobiliproteins, especially PE. To make sure the deduction, we carried out additional experiment by using recombinant PE. We expressed the recombinant α- and β-subunits of PE (rPEα and rPEβ, respectively), and then prepared their peptides by thermolysin hydrolysis. As a result, these peptides showed high ACE inhibitory activities (rPEα: 94.4%; rPEβ: 87.0%). Therefore, we concluded that the original proteins of dulse ACE inhibitory peptides were phycobiliproteins. PMID:26861357

  8. Angiotensin I Converting Enzyme Inhibitory Peptides Derived from Phycobiliproteins of Dulse Palmaria palmata.

    PubMed

    Furuta, Tomoe; Miyabe, Yoshikatsu; Yasui, Hajime; Kinoshita, Yasunori; Kishimura, Hideki

    2016-02-04

    We examined the inhibitory activity of angiotensin I converting enzyme (ACE) in protein hydrolysates from dulse, Palmaria palmata. The proteins extracted from dulse were mainly composed of phycoerythrin (PE) followed by phycocyanin (PC) and allophycocyanin (APC). The dulse proteins showed slight ACE inhibitory activity, whereas the inhibitory activity was extremely enhanced by thermolysin hydrolysis. The ACE inhibitory activity of hydrolysates was hardly affected by additional pepsin, trypsin and chymotrypsin treatments. Nine ACE inhibitory peptides (YRD, AGGEY, VYRT, VDHY, IKGHY, LKNPG, LDY, LRY, FEQDWAS) were isolated from the hydrolysates by reversed-phase high-performance liquid chromatography (HPLC), and it was demonstrated that the synthetic peptide LRY (IC50: 0.044 μmol) has remarkably high ACE inhibitory activity. Then, we investigated the structural properties of dulse phycobiliproteins to discuss the origin of dulse ACE inhibitory peptides. Each dulse phycobiliprotein possesses α-subunit (Mw: 17,477-17,638) and β-subunit (Mw: 17,455-18,407). The sequences of YRD, AGGEY, VYRT, VDHY, LKNPG and LDY were detected in the primary structure of PE α-subunit, and the LDY also exists in the APC α- and β-subunits. In addition, the LRY sequence was found in the β-subunits of PE, PC and APC. From these results, it was suggested that the dulse ACE inhibitory peptides were derived from phycobiliproteins, especially PE. To make sure the deduction, we carried out additional experiment by using recombinant PE. We expressed the recombinant α- and β-subunits of PE (rPEα and rPEβ, respectively), and then prepared their peptides by thermolysin hydrolysis. As a result, these peptides showed high ACE inhibitory activities (rPEα: 94.4%; rPEβ: 87.0%). Therefore, we concluded that the original proteins of dulse ACE inhibitory peptides were phycobiliproteins.

  9. Angiotensin I Converting Enzyme Inhibitory Peptides Derived from Phycobiliproteins of Dulse Palmaria palmata.

    PubMed

    Furuta, Tomoe; Miyabe, Yoshikatsu; Yasui, Hajime; Kinoshita, Yasunori; Kishimura, Hideki

    2016-02-01

    We examined the inhibitory activity of angiotensin I converting enzyme (ACE) in protein hydrolysates from dulse, Palmaria palmata. The proteins extracted from dulse were mainly composed of phycoerythrin (PE) followed by phycocyanin (PC) and allophycocyanin (APC). The dulse proteins showed slight ACE inhibitory activity, whereas the inhibitory activity was extremely enhanced by thermolysin hydrolysis. The ACE inhibitory activity of hydrolysates was hardly affected by additional pepsin, trypsin and chymotrypsin treatments. Nine ACE inhibitory peptides (YRD, AGGEY, VYRT, VDHY, IKGHY, LKNPG, LDY, LRY, FEQDWAS) were isolated from the hydrolysates by reversed-phase high-performance liquid chromatography (HPLC), and it was demonstrated that the synthetic peptide LRY (IC50: 0.044 μmol) has remarkably high ACE inhibitory activity. Then, we investigated the structural properties of dulse phycobiliproteins to discuss the origin of dulse ACE inhibitory peptides. Each dulse phycobiliprotein possesses α-subunit (Mw: 17,477-17,638) and β-subunit (Mw: 17,455-18,407). The sequences of YRD, AGGEY, VYRT, VDHY, LKNPG and LDY were detected in the primary structure of PE α-subunit, and the LDY also exists in the APC α- and β-subunits. In addition, the LRY sequence was found in the β-subunits of PE, PC and APC. From these results, it was suggested that the dulse ACE inhibitory peptides were derived from phycobiliproteins, especially PE. To make sure the deduction, we carried out additional experiment by using recombinant PE. We expressed the recombinant α- and β-subunits of PE (rPEα and rPEβ, respectively), and then prepared their peptides by thermolysin hydrolysis. As a result, these peptides showed high ACE inhibitory activities (rPEα: 94.4%; rPEβ: 87.0%). Therefore, we concluded that the original proteins of dulse ACE inhibitory peptides were phycobiliproteins. PMID:26861357

  10. Characterization of geographically distinct bacterial communities associated with coral mucus produced by Acropora spp. and Porites spp.

    PubMed

    McKew, B A; Dumbrell, A J; Daud, S D; Hepburn, L; Thorpe, E; Mogensen, L; Whitby, C

    2012-08-01

    Acropora and Porites corals are important reef builders in the Indo-Pacific and Caribbean. Bacteria associated with mucus produced by Porites spp. and Acropora spp. from Caribbean (Punta Maroma, Mexico) and Indo-Pacific (Hoga and Sampela, Indonesia) reefs were determined. Analysis of pyrosequencing libraries showed that bacterial communities from Caribbean corals were significantly more diverse (H', 3.18 to 4.25) than their Indonesian counterparts (H', 2.54 to 3.25). Dominant taxa were Gammaproteobacteria, Alphaproteobacteria, Firmicutes, and Cyanobacteria, which varied in relative abundance between coral genera and region. Distinct coral host-specific communities were also found; for example, Clostridiales were dominant on Acropora spp. (at Hoga and the Mexican Caribbean) compared to Porites spp. and seawater. Within the Gammproteobacteria, Halomonas spp. dominated sequence libraries from Porites spp. (49%) and Acropora spp. (5.6%) from the Mexican Caribbean, compared to the corresponding Indonesian coral libraries (<2%). Interestingly, with the exception of Porites spp. from the Mexican Caribbean, there was also a ubiquity of Psychrobacter spp., which dominated Acropora and Porites libraries from Indonesia and Acropora libraries from the Caribbean. In conclusion, there was a dominance of Halomonas spp. (associated with Acropora and Porites [Mexican Caribbean]), Firmicutes (associated with Acropora [Mexican Caribbean] and with Acropora and Porites [Hoga]), and Cyanobacteria (associated with Acropora and Porites [Hoga] and Porites [Sampela]). This is also the first report describing geographically distinct Psychrobacter spp. associated with coral mucus. In addition, the predominance of Clostridiales associated with Acropora spp. provided additional evidence for coral host-specific microorganisms.

  11. Characterization of Geographically Distinct Bacterial Communities Associated with Coral Mucus Produced by Acropora spp. and Porites spp.

    PubMed Central

    McKew, B. A.; Dumbrell, A. J.; Daud, S. D.; Hepburn, L.; Thorpe, E.; Mogensen, L.

    2012-01-01

    Acropora and Porites corals are important reef builders in the Indo-Pacific and Caribbean. Bacteria associated with mucus produced by Porites spp. and Acropora spp. from Caribbean (Punta Maroma, Mexico) and Indo-Pacific (Hoga and Sampela, Indonesia) reefs were determined. Analysis of pyrosequencing libraries showed that bacterial communities from Caribbean corals were significantly more diverse (H′, 3.18 to 4.25) than their Indonesian counterparts (H′, 2.54 to 3.25). Dominant taxa were Gammaproteobacteria, Alphaproteobacteria, Firmicutes, and Cyanobacteria, which varied in relative abundance between coral genera and region. Distinct coral host-specific communities were also found; for example, Clostridiales were dominant on Acropora spp. (at Hoga and the Mexican Caribbean) compared to Porites spp. and seawater. Within the Gammproteobacteria, Halomonas spp. dominated sequence libraries from Porites spp. (49%) and Acropora spp. (5.6%) from the Mexican Caribbean, compared to the corresponding Indonesian coral libraries (<2%). Interestingly, with the exception of Porites spp. from the Mexican Caribbean, there was also a ubiquity of Psychrobacter spp., which dominated Acropora and Porites libraries from Indonesia and Acropora libraries from the Caribbean. In conclusion, there was a dominance of Halomonas spp. (associated with Acropora and Porites [Mexican Caribbean]), Firmicutes (associated with Acropora [Mexican Caribbean] and with Acropora and Porites [Hoga]), and Cyanobacteria (associated with Acropora and Porites [Hoga] and Porites [Sampela]). This is also the first report describing geographically distinct Psychrobacter spp. associated with coral mucus. In addition, the predominance of Clostridiales associated with Acropora spp. provided additional evidence for coral host-specific microorganisms. PMID:22636010

  12. on the growth and photochemical efficiency of Acropora cervicornis

    NASA Astrophysics Data System (ADS)

    Enochs, I. C.; Manzello, D. P.; Carlton, R.; Schopmeyer, S.; van Hooidonk, R.; Lirman, D.

    2014-06-01

    The effects of light and elevated pCO2 on the growth and photochemical efficiency of the critically endangered staghorn coral, Acropora cervicornis, were examined experimentally. Corals were subjected to high and low treatments of CO2 and light in a fully crossed design and monitored using 3D scanning and buoyant weight methodologies. Calcification rates, linear extension, as well as colony surface area and volume of A. cervicornis were highly dependent on light intensity. At pCO2 levels projected to occur by the end of the century from ocean acidification (OA), A. cervicornis exhibited depressed calcification, but no change in linear extension. Photochemical efficiency ( F v / F m ) was higher at low light, but unaffected by CO2. Amelioration of OA-depressed calcification under high-light treatments was not observed, and we suggest that the high-light intensity necessary to reach saturation of photosynthesis and calcification in A. cervicornis may limit the effectiveness of this potentially protective mechanism in this species. High CO2 causes depressed skeletal density, but not linear extension, illustrating that the measurement of extension by itself is inadequate to detect CO2 impacts. The skeletal integrity of A. cervicornis will be impaired by OA, which may further reduce the resilience of the already diminished populations of this endangered species.

  13. Characterization of the telomere regions of scleractinian coral, Acropora surculosa.

    PubMed

    Sinclair, Colleen S; Richmond, Robert H; Ostrander, Gary K

    2007-03-01

    Terminal ends of vertebrate chromosomes are protected by tandem repeats of the sequence (TTAGGG). First thought to be vertebrate specific, (TTAGGG)( n ) has recently been identified in several aquatic invertebrates including sea urchin (Strongylocentrotus purpuratus), bay scallop (Argopecten irradians), and wedgeshell clam (Donax trunculus). We analyzed genomic DNA from scleractinian corals, Acropora surculosa, Favia pallida, Leptoria phrygia, and Goniastrea retiformis to determine the telomere sequence. Southern blot analysis suggests the presence of the vertebrate telomere repeats in all four species. Treatment of A. surculosa sperm DNA with Bal31 exonuclease revealed progressive shortening of the DNA fragments positive for the (TTAGGG)(22) sequence, supporting location of the repeats at the chromosome ends. The presence of the vertebrate telomere repeats in corals is evidence that the (TTAGGG)( n ) sequence is highly conserved among a divergent group of vertebrate and invertebrate species. Corals are members of the Lower Metazoans, the group of organisms that span the gap between the fungi and higher metazoans. Corals are the most basal organism reported to have the (TTAGGG)( n ) sequence to date, which suggests that the vertebrate telomere sequence may be much older than previously thought and that corals may share a number of genes with their higher relatives.

  14. Structure and palaeoenvironmental implications of inter-branch coenosteum-rich skeleton in corymbose Acropora species

    NASA Astrophysics Data System (ADS)

    Sadler, J.; Webb, G. E.; Nothdurft, L. D.

    2015-03-01

    Coral reefs provide an increasingly important archive of palaeoclimate data that can be used to constrain climate model simulations. Reconstructing past environmental conditions may also provide insights into the potential of reef systems to survive changes in the Earth's climate. Reef-based palaeoclimate reconstructions are predominately derived from colonies of massive Porites, with the most abundant genus in the Indo-Pacific— Acropora—receiving little attention owing to their branching growth trajectories, high extension rates and secondary skeletal thickening. However, inter-branch skeleton (consisting of both coenosteum and corallites) near the bases of corymbose Acropora colonies holds significant potential as a climate archive. This region of Acropora skeleton is atypical, having simple growth trajectories with parallel corallites, approximately horizontal density banding, low apparent extension rates and a simple microstructure with limited secondary thickening. Hence, inter-branch skeleton in Acropora bears more similarities to the coralla of massive corals, such as Porites, than to traditional Acropora branches. Cyclic patterns of Sr/Ca ratios in this structure suggest that the observed density banding is annual in nature, thus opening up the potential to use abundant corymbose Acropora for palaeoclimate reconstruction.

  15. The corallivorous flatworm Amakusaplana acroporae: an invasive species threat to coral reefs?

    NASA Astrophysics Data System (ADS)

    Hume, Benjamin C. C.; D'Angelo, Cecilia; Cunnington, Anna; Smith, Edward G.; Wiedenmann, Jörg

    2014-03-01

    Fatal infestations of land-based Acropora cultures with so-called Acropora- eating flatworms (AEFWs) are a global phenomenon. We evaluate the hypothesis that AEFWs represent a risk to coral reefs by studying the biology and the invasive potential of an AEFW strain from the UK. Molecular analyses identified this strain as Amakusaplana acroporae, a new species described from two US aquaria and one natural location in Australia. Our molecular data together with life history strategies described here suggest that this species accounts for most reported cases of AEFW infestations. We show that local parasitic activity impairs the light-acclimation capacity of the whole host colony. A. acroporae acquires excellent camouflage by harbouring photosynthetically competent, host-derived zooxanthellae and pigments of the green-fluorescent protein family. It shows a preference for Acropora valida but accepts a broad host range. Parasite survival in isolation (5-7 d) potentially allows for an invasion when introduced as non-native species in coral reefs.

  16. The Montastraea faveolata microbiome: ecological and temporal influences on a Caribbean reef-building coral in decline.

    PubMed

    Kimes, Nikole E; Johnson, Wesley R; Torralba, Manolito; Nelson, Karen E; Weil, Ernesto; Morris, Pamela J

    2013-07-01

    Coral-associated microbial communities, including protists, bacteria, archaea and viruses, are important components of the coral holobiont that influence the health of corals and coral reef ecosystems. Evidence suggests that the composition of these microbial communities is affected by numerous parameters; however, little is known about the confluence of these ecological and temporal effects. In this study, we used ribosomal RNA gene sequencing to identify the zooxanthellae, bacteria and archaea associated with healthy and yellow band diseased (YBD) colonies in the Media Luna reef of La Parguera, Puerto Rico, in order to examine the influence of YBD on the Montastraea faveolata microbiome. In addition, we evaluated the influence of season on the differences between healthy and YBD M. faveolata microbiomes by sampling from the same tagged colonies in both March and September of 2007. To the best of our knowledge, this is the first coral microbiome study to examine sequences from the zooxanthellar, bacterial and archaeal communities simultaneously from individual coral samples. Our results confirm differences in the M. faveolata zooxanthellar, bacterial and archaeal communities between healthy and YBD colonies in March; however, the September communities do not exhibit the same differences. Moreover, we provide evidence that the differences in the M. faveolata microbiomes between March and September are more significant than those observed between healthy and YBD. This data suggest that the entire coral microbiome, not just the bacterial community, is a dynamic environment where both disease and season play important roles.

  17. Microbial diversity associated with four functional groups of benthic reef algae and the reef-building coral Montastraea annularis.

    PubMed

    Barott, Katie L; Rodriguez-Brito, Beltran; Janouškovec, Jan; Marhaver, Kristen L; Smith, Jennifer E; Keeling, Patrick; Rohwer, Forest L

    2011-05-01

    The coral reef benthos is primarily colonized by corals and algae, which are often in direct competition with one another for space. Numerous studies have shown that coral-associated Bacteria are different from the surrounding seawater and are at least partially species specific (i.e. the same bacterial species on the same coral species). Here we extend these microbial studies to four of the major ecological functional groups of algae found on coral reefs: upright and encrusting calcifying algae, fleshy algae, and turf algae, and compare the results to the communities found on the reef-building coral Montastraea annularis. It was found using 16S rDNA tag pyrosequencing that the different algal genera harbour characteristic bacterial communities, and these communities were generally more diverse than those found on corals. While the majority of coral-associated Bacteria were related to known heterotrophs, primarily consuming carbon-rich coral mucus, algal-associated communities harboured a high percentage of autotrophs. The majority of algal-associated autotrophic Bacteria were Cyanobacteria and may be important for nitrogen cycling on the algae. There was also a rich diversity of photosynthetic eukaryotes associated with the algae, including protists, diatoms, and other groups of microalgae. Together, these observations support the hypothesis that coral reefs are a vast landscape of distinctive microbial communities and extend the holobiont concept to benthic algae.

  18. Location-Specific Responses to Thermal Stress in Larvae of the Reef-Building Coral Montastraea faveolata

    PubMed Central

    Polato, Nicholas R.; Voolstra, Christian R.; Schnetzer, Julia; DeSalvo, Michael K.; Randall, Carly J.; Szmant, Alina M.; Medina, Mónica; Baums, Iliana B.

    2010-01-01

    Background The potential to adapt to a changing climate depends in part upon the standing genetic variation present in wild populations. In corals, the dispersive larval phase is particularly vulnerable to the effects of environmental stress. Larval survival and response to stress during dispersal and settlement will play a key role in the persistence of coral populations. Methodology/Principal Findings To test the hypothesis that larval transcription profiles reflect location-specific responses to thermal stress, symbiont-free gametes from three to four colonies of the scleractinian coral Montastraea faveolata were collected from Florida and Mexico, fertilized, and raised under mean and elevated (up 1 to 2°C above summer mean) temperatures. These locations have been shown to exchange larvae frequently enough to prevent significant differentiation of neutral loci. Differences among 1,310 unigenes were simultaneously characterized using custom cDNA microarrays, allowing investigation of gene expression patterns among larvae generated from wild populations under stress. Results show both conserved and location-specific variation in key processes including apoptosis, cell structuring, adhesion and development, energy and protein metabolism, and response to stress, in embryos of a reef-building coral. Conclusions/Significance These results provide first insights into location-specific variation in gene expression in the face of gene flow, and support the hypothesis that coral host genomes may house adaptive potential needed to deal with changing environmental conditions. PMID:20585643

  19. Circadian Cycles of Gene Expression in the Coral, Acropora millepora

    PubMed Central

    Brady, Aisling K.; Snyder, Kevin A.; Vize, Peter D.

    2011-01-01

    Background Circadian rhythms regulate many physiological, behavioral and reproductive processes. These rhythms are often controlled by light, and daily cycles of solar illumination entrain many clock regulated processes. In scleractinian corals a number of different processes and behaviors are associated with specific periods of solar illumination or non-illumination—for example, skeletal deposition, feeding and both brooding and broadcast spawning. Methodology/Principal Findings We have undertaken an analysis of diurnal expression of the whole transcriptome and more focused studies on a number of candidate circadian genes in the coral Acropora millepora using deep RNA sequencing and quantitative PCR. Many examples of diurnal cycles of RNA abundance were identified, some of which are light responsive and damped quickly under constant darkness, for example, cryptochrome 1 and timeless, but others that continue to cycle in a robust manner when kept in constant darkness, for example, clock, cryptochrome 2, cycle and eyes absent, indicating that their transcription is regulated by an endogenous clock entrained to the light-dark cycle. Many other biological processes that varied between day and night were also identified by a clustering analysis of gene ontology annotations. Conclusions/Significance Corals exhibit diurnal patterns of gene expression that may participate in the regulation of circadian biological processes. Rhythmic cycles of gene expression occur under constant darkness in both populations of coral larvae that lack zooxanthellae and in individual adult tissue containing zooxanthellae, indicating that transcription is under the control of a biological clock. In addition to genes potentially involved in regulating circadian processes, many other pathways were found to display diel cycles of transcription. PMID:21949855

  20. Sr/Ca proxy sea-surface temperature reconstructions from modern and holocene Montastraea faveolata specimens from the Dry Tortugas National Park

    USGS Publications Warehouse

    Flannery, Jennifer A.; Poore, Richard Z.

    2013-01-01

    Sr/Ca ratios from skeletal samples from two Montastraea faveolata corals (one modern, one Holocene, ~6 Ka) from the Dry Tortugas National Park were measured as a proxy for sea-surface temperature (SST). We sampled coral specimens with a computer-driven triaxial micromilling machine, which yielded an average of 15 homogenous samples per annual growth increment. We regressed Sr/Ca values from resulting powdered samples against a local SST record to obtain a calibration equation of Sr/Ca = -0.0392 SST + 10.205, R = -0.97. The resulting calibration was used to generate a 47-year modern (1961-2008) and a 7-year Holocene (~6 Ka) Sr/Ca subannually resolved proxy record of SST. The modern M. faveolata yields well-defined annual Sr/Ca cycles ranging in amplitude from ~0.3 and 0.5 mmol/mol. The amplitude of ~0.3 to 0.5 mmol/mol equates to a 10-15°C seasonal SST amplitude, which is consistent with available local instrumental records. Summer maxima proxy SSTs calculated from the modern coral Sr/ Ca tend to be fairly stable: most SST maxima from 1961–2008 are 29°C ± 1°C. In contrast, winter minimum SST calculated in the 47-year modern time-series are highly variable, with a cool interval in the early to mid-1970s. The Holocene (~6 Ka) Montastraea faveolata coral also yields distinct annual Sr/Ca cycles with amplitudes ranging from ~0.3 to 0.6 mmol/mol. Absolute Sr/Ca values and thus resulting SST estimates over the ~7-year long record are similar to those from the modern coral. We conclude that Sr/Ca from Montastraea faveolata has high potential for developing subannually resolved Holocene SST records.

  1. Calibration and Assessment of the New Acropora 'Inter-Branch Skeleton' Palaeothermometer.

    NASA Astrophysics Data System (ADS)

    Sadler, J.; Webb, G. E.; Zhao, J. X.; Nothdurft, L. D.

    2014-12-01

    Coral reefs provide an increasingly important archive of palaeoclimate data that can be used to constrain climate model simulations. Reconstructing past environments may also provide insights into the potential of reef systems to survive changes in the Earth's climate. Geochemically based climate reconstructions are predominately acquired from massive Porites colonies, yet there remain significant spatial and temporal gaps in our understanding of climate evolution where no suitable coralla have been recovered. Branching corals are commonly the dominant species in modern reef facies and their abundance suggests an untapped source for this missing information. The potential of 'inter-branch skeleton' in corymbose Acropora to act as a new palaeoclimate archive is significant. Scanning Electron Microscopy of inter-branch skeleton in Acropora from Heron Reef, southern Great Barrier Reef, reveals a lack of secondary thickening deposits that typically characterize Acropora branches and renders them unsuitable for geochemical archives. Annual density banding, similar to that used for chronological determination of geochemical sampling in massive corals, is also observed within Acropora inter-branch skeleton. Clear seasonal signals in Sr/Ca within the skeletal structure will be correlated against the network of in situ temperature recorders in Heron lagoon and on the southern reef slope to provide a new palaeotemperature transfer equation.

  2. Geographic differences in species boundaries among members of the Montastraea annularis complex based on molecular and morphological markers.

    PubMed

    Fukami, Hironobu; Budd, Ann F; Levitan, Don R; Jara, Javier; Kersanach, Ralf; Knowlton, Nancy

    2004-02-01

    The three members of the Montastraea annularis complex (M. annularis, M. franksi, and M. faveolata) are dominant reef builders in the western Atlantic whose species status has been controversial for over a decade. Although differences in colony morphology and reproductive characteristics exist, interspecific fertilizations are possible in the laboratory and genetic differentiation is slight. Here we compare the three taxa genetically and morphologically in Panama and the Bahamas, widely separated locations spanning most of their geographic ranges. In Panama, analyses of three AFLP loci, a noncoding region of the mitochondrial genome, and ITS sequences reveal that M. faveolata is strongly differentiated genetically. Discriminant function analysis also indicates no overlap with the other two species in the fine structure of the corallites that comprise the colony. Genetic analyses of larvae from interspecific crosses between M. faveolata and the other two taxa confirmed the hybrid status of the larvae, but no examples of the most probable F1 genotype were observed in the field. Although M. annularis and M. franksi were more similar, they also exhibited strong frequency differences at two AFLP loci and in the mitochondrial noncoding region, as well as distinct corallite structure. In the Bahamas, in contrast, the three taxa exhibited overlapping morphologies. Montastraeafranksi and M. annularis were indistinguishable genetically, and M. faveolata was distinct at fewer genetic loci. Once again, however, the most probable F1 genotype involving M. faveolata was not observed. Geographic differences between Panama and the Bahamas explain why past studies have come to different conclusions concerning the status of the three species. In general, the genetic and morphological data suggest a north to south hybridization gradient, with evidence for introgression strongest in the north. However, reproductive data show no such trend, with intrinsic barriers to gene flow

  3. Geographic differences in vertical connectivity in the Caribbean coral Montastraea cavernosa despite high levels of horizontal connectivity at shallow depths.

    PubMed

    Serrano, X; Baums, I B; O'Reilly, K; Smith, T B; Jones, R J; Shearer, T L; Nunes, F L D; Baker, A C

    2014-09-01

    The deep reef refugia hypothesis proposes that deep reefs can act as local recruitment sources for shallow reefs following disturbance. To test this hypothesis, nine polymorphic DNA microsatellite loci were developed and used to assess vertical connectivity in 583 coral colonies of the Caribbean depth-generalist coral Montastraea cavernosa. Samples were collected from three depth zones (≤10, 15-20 and ≥25 m) at sites in Florida (within the Upper Keys, Lower Keys and Dry Tortugas), Bermuda, and the U.S. Virgin Islands. Migration rates were estimated to determine the probability of coral larval migration from shallow to deep and from deep to shallow. Finally, algal symbiont (Symbiodinium spp.) diversity and distribution were assessed in a subset of corals to test whether symbiont depth zonation might indicate limited vertical connectivity. Overall, analyses revealed significant genetic differentiation by depth in Florida, but not in Bermuda or the U.S. Virgin Islands, despite high levels of horizontal connectivity between these geographic locations at shallow depths. Within Florida, greater vertical connectivity was observed in the Dry Tortugas compared to the Lower or Upper Keys. However, at all sites, and regardless of the extent of vertical connectivity, migration occurred asymmetrically, with greater likelihood of migration from shallow to intermediate/deep habitats. Finally, most colonies hosted a single Symbiodinium type (C3), ruling out symbiont depth zonation of the dominant symbiont type as a structuring factor. Together, these findings suggest that the potential for shallow reefs to recover from deep-water refugia in M. cavernosa is location-specific, varying among and within geographic locations likely as a consequence of local hydrology.

  4. Geographic differences in vertical connectivity in the Caribbean coral Montastraea cavernosa despite high levels of horizontal connectivity at shallow depths.

    PubMed

    Serrano, X; Baums, I B; O'Reilly, K; Smith, T B; Jones, R J; Shearer, T L; Nunes, F L D; Baker, A C

    2014-09-01

    The deep reef refugia hypothesis proposes that deep reefs can act as local recruitment sources for shallow reefs following disturbance. To test this hypothesis, nine polymorphic DNA microsatellite loci were developed and used to assess vertical connectivity in 583 coral colonies of the Caribbean depth-generalist coral Montastraea cavernosa. Samples were collected from three depth zones (≤10, 15-20 and ≥25 m) at sites in Florida (within the Upper Keys, Lower Keys and Dry Tortugas), Bermuda, and the U.S. Virgin Islands. Migration rates were estimated to determine the probability of coral larval migration from shallow to deep and from deep to shallow. Finally, algal symbiont (Symbiodinium spp.) diversity and distribution were assessed in a subset of corals to test whether symbiont depth zonation might indicate limited vertical connectivity. Overall, analyses revealed significant genetic differentiation by depth in Florida, but not in Bermuda or the U.S. Virgin Islands, despite high levels of horizontal connectivity between these geographic locations at shallow depths. Within Florida, greater vertical connectivity was observed in the Dry Tortugas compared to the Lower or Upper Keys. However, at all sites, and regardless of the extent of vertical connectivity, migration occurred asymmetrically, with greater likelihood of migration from shallow to intermediate/deep habitats. Finally, most colonies hosted a single Symbiodinium type (C3), ruling out symbiont depth zonation of the dominant symbiont type as a structuring factor. Together, these findings suggest that the potential for shallow reefs to recover from deep-water refugia in M. cavernosa is location-specific, varying among and within geographic locations likely as a consequence of local hydrology. PMID:25039722

  5. Yellow band disease compromises the reproductive output of the Caribbean reef-building coral Montastraea faveolata (Anthozoa, Scleractinia).

    PubMed

    Weil, Ernesto; Cróquer, Aldo; Urreiztieta, Isabel

    2009-11-16

    Sexual reproduction is critical to coral population dynamics and the long-term regeneration of coral reefs. Bleaching, disease, and/or anthropogenic-induced tissue/colony loss reduce reproductive output. This is the first attempt to explore the effect of a biotic disease on the reproduction of scleractinian corals. The study aimed to assess the effect of yellow band disease (YBD) on the reproduction of the important Caribbean reef-builder Montastraea faveolata. Tissue samples were collected from diseased, transition, and healthy-looking areas in each of 5 infected colonies and from 5 healthy controls in southwest Puerto Rico. The effect of disease-induced mortality was assessed by collecting samples from the edge and center of surviving small and large, healthy-looking tissue patches from large, previously infected tagged colonies. Fecundity was significantly lower in disease lesions compared to transition and healthy-looking tissues and the controls (99% fewer eggs). Fecundity in transition areas was significantly lower (50%) than in healthy-looking tissues in diseased colonies, which had 23% lower fecundity than control tissues. Although this fecundity drop was not statistically significant, it could indicate a systemic effect of YBD across the colony. Large and small patches had 64 and 84% fewer eggs than controls, respectively, and edge polyps had 97% fewer eggs than those in central control areas. Field observations of the spawning behavior of each tissue area corroborated the histological results. Our results indicate that YBD significantly compromises the reproductive output of M. faveolata, potentially reducing the fitness and consequently, the recovery of this important reef-building species on Caribbean coral reefs.

  6. Effects of titanium dioxide (TiO2 ) nanoparticles on caribbean reef-building coral (Montastraea faveolata).

    PubMed

    Jovanović, Boris; Guzmán, Héctor M

    2014-06-01

    Increased use of manufactured titanium dioxide nanoparticles (nano-TiO2 ) is causing a rise in their concentration in the aquatic environment, including coral reef ecosystems. Caribbean mountainous star coral (Montastraea faveolata) has frequently been used as a model species to study gene expression during stress and bleaching events. Specimens of M. faveolata were collected in Panama and exposed for 17 d to nano-TiO2 suspensions (0.1 mg L(-1) and 10 mg L(-1) ). Exposure to nano-TiO2 caused significant zooxanthellae expulsion in all the colonies, without mortality. Induction of the gene for heat-shock protein 70 (HSP70) was observed during an early stage of exposure (day 2), indicating acute stress. However, there was no statistical difference in HSP70 expression on day 7 or 17, indicating possible coral acclimation and recovery from stress. No other genes were significantly upregulated. Inductively coupled plasma mass spectrometry analysis revealed that nano-TiO2 was predominantly trapped and stored within the posterior layer of the coral fragment (burrowing sponges, bacterial and fungal mats). The bioconcentration factor in the posterior layer was close to 600 after exposure to 10 mg L(-1) of nano-TiO2 for 17 d. The transient increase in HSP70, expulsion of zooxanthellae, and bioaccumulation of nano-TiO2 in the microflora of the coral colony indicate the potential of such exposure to induce stress and possibly contribute to an overall decrease in coral populations.

  7. Decade-Scale Trend in Sea Water Salinity Revealed through d18O Analysis of Montastraea Annularis Annual Growth Bands

    USGS Publications Warehouse

    Halley, Robert B.; Swart, Peter K.; Dodge, Richard E.; Hudson, J. Harold

    1994-01-01

    Stable oxygen isotope ratios (18O) of coral skeletons are influenced by ambient water temperature and by the oxygen isotope ratio in the surrounding sea water, which, in turn, is linked to evaporation (salinity) and precipitation. To investigate this relationship more thoroughly, we collected hourly temperature data from the Hen and Chickens Reef in the Florida Keys between 1975 and 1988 and compared them to the 18O of Montastraea annularis skeleton that grew during the same interval. To ensure that we obtained the correct oxygen isotopic range in the skeleton we typically sampled the coral at a resolution of 20-30 samples in 1 year; in 1 year we sampled the coral at a resolution of 70 samples x year-1. Despite our high-resolution sampling, we were unable to obtain the full temperature-induced 18O range in the skeleton. Our data suggest that, during the summer, evaporation causes isotopic enrichment in the water, partially masking the temperature-induced signal. Our data also show that oxygen isotopic composition of seawater at the reef has increased since 1981. This increase indicates that salinity has increased slightly during the past decade, perhaps as a result of increased evaporation in waters of Florida Bay and the Keys. This phenomenon is probably not caused by a decrease in the outflow of freshwater into Florida Bay from the Everglades but may be related to the measured deficit in precipitation that has occurred over the past decade.

  8. Simulation and observations of annual density banding in skeletons of Montastraea (Cnidaria: Scleractinia) growing under thermal stress associated with ocean warming

    USGS Publications Warehouse

    Worum, F.P.; Carricart-Ganivet, J. P.; Benson, L.; Golicher, D.

    2007-01-01

    We present a model of annual density banding in skeletons of Montastraea coral species growing under thermal stress associated with an ocean-warming scenario. The model predicts that at sea-surface temperatures (SSTs) <29??C, high-density bands (HDBs) are formed during the warmest months of the year. As temperature rises and oscillates around the optimal calcification temperature, an annual doublet in the HDB (dHDB) occurs that consists of two narrow HDBs. The presence of such dHDBs in skeletons of Montastraea species is a clear indication of thermal stress. When all monthly SSTs exceed the optimal calcification temperature, HDBs form during the coldest, not the warmest, months of the year. In addition, a decline in mean-annual calcification rate also occurs during this period of elevated SST. A comparison of our model results with annual density patterns observed in skeletons of M. faveolata and M. franksi, collected from several localities in the Mexican Caribbean, indicates that elevated SSTs are already resulting in the presence of dHDBs as a first sign of thermal stress, which occurs even without coral bleaching. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

  9. Evidence of Last Interglacial sea-level oscillations and recent tectonism in the Late Pleistocene Falmouth Formation of Jamaica

    NASA Astrophysics Data System (ADS)

    Skrivanek, A.; Dutton, A.; Stemann, T.

    2015-12-01

    The timing and rates of sea-level change during Marine Isotope Stage 5e (MIS 5e) are poorly constrained. Across the Caribbean, many MIS 5e reefs are exposed above modern sea level, and have been studied extensively to understand sea level and ice sheet dynamics during an interglacial climate. This study investigates potential evidence for sub-orbital sea-level oscillations in the limestone Falmouth Formation from the northern and southwestern coastlines of Jamaica, a tectonically active island on the northern boundary of the Caribbean Plate. Vertical exposures of MIS 5e reefs contain multiple facies transitions that are sometimes associated with sharp unconformities. Outcrops at East Rio Bueno contain a distinct change in coral taxonomy from an assemblage of in situ Montastraea spp., Siderastrea and Diploria sp. encrusted by coralline algae, next to a repeated succession of Porites furcata, Acropora cervicornis, coralline algae and Porites astreoides, to in situ P. furcata. This is overlain by a fining-upwards sequence of coral rubble, a laterally persistent layer of small in situ Siderastrea and a ~1-m thick caprock. Near Oracabessa, a unit dominated by Acropora palmata clearly transitions into in situ Montastraea spp., Siderastrea, Colpophyllia natans, and Diploria sp. overlain by A. cervicornis. An abrupt vertical displacement of the sequence, indicating faulting, was observed at Oracabessa. Along the south coast, transitions in coral assemblages were also noted upsection. Common facies observed include in situ A. palmata and/or rubble, with a trend of reduction in algal encrustation upsection, capped by head corals and a regressive beach unit. The structure and composition of reefs preserved in the Falmouth Formation provide detailed information about sea-level behavior during MIS 5e, that will be used to test the hypothesis that sub-orbital sea-level oscillations occurred during the MIS 5e highstand. Evidence of tectonic activity along portions of the northern

  10. High reproductive synchrony of Acropora (Anthozoa: Scleractinia) in the Gulf of Aqaba, Red Sea

    PubMed Central

    Bouwmeester, Jessica; Berumen, Michael L.

    2015-01-01

    Coral spawning in the northern Gulf of Aqaba has been reported to be asynchronous, making it almost unique when compared to other regions in the world. Here, we document the reproductive condition of Acropora corals in early June 2014 in Dahab, in the Gulf of Aqaba, 125 km south of previous studies conducted in Eilat, Israel. Seventy-eight percent of Acropora colonies from 14 species had mature eggs, indicating that most colonies will spawn on or around the June full moon, with a very high probability of multi-species synchronous spawning. Given the proximity to Eilat, we predict that a comparable sampling protocol would detect similar levels of reproductive synchrony throughout the Gulf of Aqaba consistent with the hypothesis that high levels of spawning synchrony are a feature of all speciose coral assemblages. PMID:25653848

  11. Pathology of tissue loss (white syndrome) in Acropora sp. corals from the Central Pacific

    USGS Publications Warehouse

    Work, Thierry M.; Aeby, Greta S.

    2011-01-01

    We performed histological examination of 69 samples of Acropora sp. manifesting different types of tissue loss (Acropora White Syndrome-AWS) from Hawaii, Johnston Atoll and American Samoa between 2002 and 2006. Gross lesions of tissue loss were observed and classified as diffuse acute, diffuse subacute, and focal to multifocal acute to subacute. Corals with acute tissue loss manifested microscopic evidence of necrosis sometimes associated with ciliates, helminths, fungi, algae, sponges, or cyanobacteria whereas those with subacute tissue loss manifested mainly wound repair. Gross lesions of AWS have multiple different changes at the microscopic level some of which involve various microorganisms and metazoa. Elucidating this disease will require, among other things, monitoring lesions over time to determine the pathogenesis of AWS and the potential role of tissue-associated microorganisms in the genesis of tissue loss. Attempts to experimentally induce AWS should include microscopic examination of tissues to ensure that potentially causative microorganisms associated with gross lesion are not overlooked.

  12. Effects of colony size and polyp position on polyp fecundity in the scleractinian coral genus Acropora

    NASA Astrophysics Data System (ADS)

    Nozawa, Yoko; Lin, Che-Hung

    2014-12-01

    This study examined the effects of colony size and polyp position on six variables of polyp fecundity [egg number, egg size, total egg volume, total testis volume, total gonad volume, and gonad ratio (egg volume/testis volume)] in three tabular Acropora corals (Scleractinia), A. hyacinthus, A. japonica, and A. solitaryensis. Samples were collected from various colony sizes ( n = 21-30 colonies species-1), just before the predicted spawning at Kochi, Japan, in 2009. Five replicate polyps were sampled at three positions (center, middle, and outer) from the center to the marginal area in each tabular colony. Results indicated effects of colony size and polyp position on both male and female gonads polyp-1. A positive effect of colony size was observed on variables of female gonads polyp-1 (egg number, total egg volume) in A. hyacinthus only, while the positive effect on the variable of male gonads polyp-1 (total testis volume) was common in all Acropora species, with total testis volume polyp-1 increasing 2-4-fold from the small (200-400 cm2) to the large size class (5,000-9,000 cm2). Among the polyp positions, lower values were observed mostly in center polyps in A. hyacinthus, while lower values were observed only in outer polyps in the other Acropora species. The distinct patterns between A. hyacinthus and the other two Acropora species suggest different reproductive strategies at the species level. Further studies are needed to confirm the prevalence of these effects in scleractinian corals, which will broaden our understanding of reproductive life history strategies and improve the estimation of reproductive performance.

  13. Gametogenesis and fecundity of Acropora tenella (Brook 1892) in a mesophotic coral ecosystem in Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Prasetia, Rian; Sinniger, Frederic; Harii, Saki

    2016-03-01

    Mesophotic coral ecosystems (below 30-40 m depth) host a large diversity of zooxanthellate coral communities and may play an important role in the ecology and conservation of coral reefs. Investigating the reproductive biology of mesophotic corals is important to understand their life history traits. Despite an increase in research on mesophotic corals in the last decade, their reproductive biology is still poorly understood. Here, gametogenesis and fecundity of the Indo-Pacific mesophotic coral , Acropora tenella, were examined in an upper mesophotic reef (40 m depth) in Okinawa, Japan for the first time. Acropora tenella is a hermaphrodite with a single annual gametogenic cycle, and both oogenesis and spermatogenesis occurring for 11-12 and 5-6 months, respectively. Timing of spawning of this species was similar to other shallow Acropora spp. in the region. However, colonies had longer gametogenic cycles and less synchronous gamete maturation compared to shallow acroporids with spawning extended over consecutive months. Both the polyp fecundity (number of eggs per polyp) and gonad index (defined as the number of eggs per square centimeter) of A. tenella were lower than most acroporids. Our findings contribute to understanding of the life history of corals on mesophotic reefs and suggest that the reproductive biology of upper mesophotic corals is similar to that of shallow-water corals.

  14. The reef-building coral Acropora conditionally hybridize under sperm limitation.

    PubMed

    Kitanobo, Seiya; Isomura, Naoko; Fukami, Hironobu; Iwao, Kenji; Morita, Masaya

    2016-08-01

    Multi-specific synchronous spawning risks both sperm limitation, which reduces fertilization success, and hybridization with other species. If available sperm of conspecifics are limited, hybridization with heterospecific sperm could be an alternative. Some species of the reef-building coral Acropora produce hybrid offspring in vitro, and therefore hybridization between such species does sometimes occur in nature. Here, we report that the interbreeding species Acropora florida and A. intermedia preferentially bred with conspecifics at optimal gamete concentrations (10(6) cells ml(-1)), but when sperm concentration was low (10(4) cells ml(-1)), A florida eggs displayed an increased incidence of fertilization by sperm of A intermedia However, A intermedia eggs never crossed with heterospecific sperm, regardless of gamete concentrations. It appears that A florida eggs conditionally hybridize with heterospecific sperm; in nature, this would allow A florida to cross with later-spawning species such as A intermedia These results indicate that hybridization between some Acropora species could occur in nature according to the number of available sperm, and the choice of heterospecific sperm for fertilization could be one of the fertilization strategies in the sperm-limited condition. PMID:27555653

  15. Bone regeneration in sheep using acropora coral, a natural resorbable scaffold, and autologous mesenchymal stem cells.

    PubMed

    Manassero, Mathieu; Viateau, Véronique; Deschepper, Mickael; Oudina, Karim; Logeart-Avramoglou, Delphine; Petite, Hervé; Bensidhoum, Morad

    2013-07-01

    Tissue constructs containing mesenchymal stem cells (MSC) are an appealing strategy for repairing massive segmental bone defects. However, their therapeutic effectiveness does not match that of autologous bone grafts; among the complicating reasons, the scaffold resorbability has been identified as a critical feature for achieving bone regeneration. In the present study, the osteogenic potential of constructs obtained by expanding autologous MSC onto granules of Acropora coral, a natural fully-resorbable scaffold, was investigated. MSC adhered and proliferated well in vitro after 1 week. When implanted in vivo into long-bone, critical-size defects in sheep (n=5), these constructs exhibited a two-fold increase in bone formation 6 months postimplantation compared to Acropora scaffolds alone (n=5). Interestingly, osteogenesis, mediated by MSC, within these constructs was found continuous not only with the bony stumps, but also at the core of the implants. Scaffold resorption was almost complete at 6 months, leading to full bone regeneration in one animal. Acropora coral appear to be an appealing scaffold for bone tissue engineering because it supported in vitro MSC adhesion and proliferation. Moreover, these results provided evidence that MSC could promote bone regeneration in sheep when loaded one a natural fully resorbable scaffold.

  16. Distribution and morphology of growth anomaliesin Acropora from the Indo-Pacific

    USGS Publications Warehouse

    Work, T.M.; Aeby, G.S.; Coles, S.L.

    2008-01-01

    We assessed the distribution and prevalence of growth anomalies (GAs) in Acropora from French Frigate Shoals (Hawaii, USA), Johnston Atoll and Tutuila (American Samoa), developed a nomenclature for gross morphology, characterized GAs at the cellular level and obtained preliminary indices of their spatial patterns and progression within coral colonies. Acropora GAs were found in all 3 regions, but the distribution, variety and prevalence of Acropora GAs was highest in American Samoa. GAs were grouped into 7 gross morphologies (exophytic, bosselated, crateriform, nodular, vermiform, fimbriate or annular). On histology, GAs consisted of hyperplastic basal body wall (calicodermis, mesoglea and gastrodermis apposed to skeleton) with 3 distinct patterns of necrosis. There was no evidence of anaplasia or mitotic figures (common but not necessarily required morphologic indicators of neoplasia). Compared to normal tissues, GAs had significantly fewer polyps, zooxanthellae within the gastrodermis of the coenenchyme, mesenterial filaments and gonads but significantly more necrosis. On 2 colonies with GAs monitored at 2 points over 11 mo, numbers of GAs per colony increased from 0.9 to 3 times the original number seen, and significant clustering of GAs occurred within colonies. The evidence of GAs being true neoplasias (tumors) is mixed, so a cautionary approach is urged in use of morphologic terminology.

  17. A genomic approach to coral-dinoflagellate symbiosis: studies of Acropora digitifera and Symbiodinium minutum

    PubMed Central

    Shinzato, Chuya; Mungpakdee, Sutada; Satoh, Nori; Shoguchi, Eiichi

    2014-01-01

    Far more intimate knowledge of scleractinian coral biology is essential in order to understand how diverse coral-symbiont endosymbioses have been established. In particular, molecular and cellular mechanisms enabling the establishment and maintenance of obligate endosymbiosis with photosynthetic dinoflagellates require further clarification. By extension, such understanding may also shed light upon environmental conditions that promote the collapse of this mutualism. Genomic data undergird studies of all symbiotic processes. Here we review recent genomic data derived from the scleractinian coral, Acropora digitifera, and the endosymbiotic dinoflagellate, Symbiodinium minutum. We discuss Acropora genes involved in calcification, embryonic development, innate immunity, apoptosis, autophagy, UV resistance, fluorescence, photoreceptors, circadian clocks, etc. We also detail gene loss in amino acid metabolism that may explain at least part of the Acropora stress-response. Characteristic features of the Symbiodinium genome are also reviewed, focusing on the expansion of certain gene families, the molecular basis for permanently condensed chromatin, unique spliceosomal splicing, and unusual gene arrangement. Salient features of the Symbiodinium plastid and mitochondrial genomes are also illuminated. Although many questions regarding these interdependent genomes remain, we summarize information necessary for future studies of coral-dinoflagellate endosymbiosis. PMID:25071748

  18. Metamorphosis and acquisition of symbiotic algae in planula larvae and primary polyps of Acropora spp.

    NASA Astrophysics Data System (ADS)

    Hirose, M.; Yamamoto, H.; Nonaka, M.

    2008-06-01

    Coral planulae settle, then metamorphose and form polyps. This study examined the morphological process of metamorphosis from planulae into primary polyps in the scleractinian corals Acropora nobilis and Acropora microphthalma, using the cnidarian neuropeptide Hym-248 . These two species release eggs that do not contain Symbiodinium. The mode of acquisition of freshly isolated Symbiodinium (zooxanthellae) (FIZ) by the non-symbiotic polyp was also examined. Non-Hym-248 treated swimming Acropora planulae did not develop blastopore, mesenteries or coelenteron until the induction of metamorphosis 16 days after fertilization. The oral pore was formed by invagination of the epidermal layer after formation of the coelenteron in metamorphosing polyps. At 3 days after settlement and metamorphosis, primary polyps exposed to FIZ established symbioses with the Symbiodinium. Two-four days after exposure to FIZ, the distribution of Symbiodinium was limited to the gastrodermis of the pharynx and basal part of the polyps. Eight-ten days after exposure to FIZ, Symbiodinium were present in gastrodermal cells throughout the polyps.

  19. Using the Acropora digitifera genome to understand coral responses to environmental change.

    PubMed

    Shinzato, Chuya; Shoguchi, Eiichi; Kawashima, Takeshi; Hamada, Mayuko; Hisata, Kanako; Tanaka, Makiko; Fujie, Manabu; Fujiwara, Mayuki; Koyanagi, Ryo; Ikuta, Tetsuro; Fujiyama, Asao; Miller, David J; Satoh, Nori

    2011-08-18

    Despite the enormous ecological and economic importance of coral reefs, the keystone organisms in their establishment, the scleractinian corals, increasingly face a range of anthropogenic challenges including ocean acidification and seawater temperature rise. To understand better the molecular mechanisms underlying coral biology, here we decoded the approximately 420-megabase genome of Acropora digitifera using next-generation sequencing technology. This genome contains approximately 23,700 gene models. Molecular phylogenetics indicate that the coral and the sea anemone Nematostella vectensis diverged approximately 500 million years ago, considerably earlier than the time over which modern corals are represented in the fossil record (∼240 million years ago). Despite the long evolutionary history of the endosymbiosis, no evidence was found for horizontal transfer of genes from symbiont to host. However, unlike several other corals, Acropora seems to lack an enzyme essential for cysteine biosynthesis, implying dependency of this coral on its symbionts for this amino acid. Corals inhabit environments where they are frequently exposed to high levels of solar radiation, and analysis of the Acropora genome data indicates that the coral host can independently carry out de novo synthesis of mycosporine-like amino acids, which are potent ultraviolet-protective compounds. In addition, the coral innate immunity repertoire is notably more complex than that of the sea anemone, indicating that some of these genes may have roles in symbiosis or coloniality. A number of genes with putative roles in calcification were identified, and several of these are restricted to corals. The coral genome provides a platform for understanding the molecular basis of symbiosis and responses to environmental changes. PMID:21785439

  20. Using the Acropora digitifera genome to understand coral responses to environmental change.

    PubMed

    Shinzato, Chuya; Shoguchi, Eiichi; Kawashima, Takeshi; Hamada, Mayuko; Hisata, Kanako; Tanaka, Makiko; Fujie, Manabu; Fujiwara, Mayuki; Koyanagi, Ryo; Ikuta, Tetsuro; Fujiyama, Asao; Miller, David J; Satoh, Nori

    2011-07-24

    Despite the enormous ecological and economic importance of coral reefs, the keystone organisms in their establishment, the scleractinian corals, increasingly face a range of anthropogenic challenges including ocean acidification and seawater temperature rise. To understand better the molecular mechanisms underlying coral biology, here we decoded the approximately 420-megabase genome of Acropora digitifera using next-generation sequencing technology. This genome contains approximately 23,700 gene models. Molecular phylogenetics indicate that the coral and the sea anemone Nematostella vectensis diverged approximately 500 million years ago, considerably earlier than the time over which modern corals are represented in the fossil record (∼240 million years ago). Despite the long evolutionary history of the endosymbiosis, no evidence was found for horizontal transfer of genes from symbiont to host. However, unlike several other corals, Acropora seems to lack an enzyme essential for cysteine biosynthesis, implying dependency of this coral on its symbionts for this amino acid. Corals inhabit environments where they are frequently exposed to high levels of solar radiation, and analysis of the Acropora genome data indicates that the coral host can independently carry out de novo synthesis of mycosporine-like amino acids, which are potent ultraviolet-protective compounds. In addition, the coral innate immunity repertoire is notably more complex than that of the sea anemone, indicating that some of these genes may have roles in symbiosis or coloniality. A number of genes with putative roles in calcification were identified, and several of these are restricted to corals. The coral genome provides a platform for understanding the molecular basis of symbiosis and responses to environmental changes.

  1. Investigating the spatial distribution and effects of nearshore topography on Acropora cervicornis abundance in Southeast Florida

    PubMed Central

    Gilliam, David S.; Walker, Brian K.

    2016-01-01

    Dense Acropora cervicornis aggregations, or patches, have been documented within nearshore habitats in Southeast Florida (SE FL) despite close proximity to numerous anthropogenic stressors and subjection to frequent natural disturbance events. Limited information has been published concerning the distribution and abundance of A. cervicornis outside of these known dense patches. The first goal of this study was to conduct a spatially extensive and inclusive survey (9.78 km2) to determine whether A. cervicornis distribution in the nearshore habitat of SE FL was spatially uniform or clustered. The second goal was to investigate potential relationships between broad-scale seafloor topography and A. cervicornis abundance using high resolution bathymetric data. Acropora cervicornis was distributed throughout the study area, and the Getis-Ord Gi* statistic and Anselin Local Moran’s I spatial cluster analysis showed significant clustering along topographic features termed ridge crests. Significant clustering was further supported by the inverse distance weighted surface model. Ordinal logistic regression indicated 1) as distance from a ridge increases, odds of reduced A. cervicornis abundance increases; 2) as topographic elevation increases, odds of increased abundance increases; and 3) as mean depth increases, odds of increased abundance increases. This study provides detailed information on A. cervicornis distribution and abundance at a regional scale and supports modeling its distributions in similar habitats elsewhere throughout the western Atlantic and Caribbean. Acropora cervicornis is frequently observed and in areas an abundant species within the nearshore habitat along the SE FL portion of the Florida Reef Tract (FRT). This study provides a better understanding of local habitat associations thus facilitating appropriate management of the nearshore environment and species conservation. The portion of the FRT between Hillsboro and Port Everglades inlets should be

  2. A spatial and vertical comparison of coral Sr/Ca variations and growth rates in Montastraea faveolata colonies in Veracruz, Mexico

    NASA Astrophysics Data System (ADS)

    Cobb, R. M.; DeLong, K. L.; Richey, J. N.; Flannery, J. A.; Kilbourne, K. H.; Smith, J. M.; Quinn, T. M.; Hudson, J. H.

    2013-12-01

    The massive coral genera Montastraea spp. is ubiquitous in modern and fossil coral reefs in the Gulf of Mexico and Caribbean Sea making this genus a potential archive for paleoclimate reconstructions. Interpretation of modern and fossil coral records requires understanding the origins of variability in coral geochemical variations on scales ranging from intracolony to regional as well as differing water depths. In 1991, the U.S. Geological Survey recovered cores from five Montastraea faveolata colonies offshore of Veracruz, Mexico (19.06°N, 96.93°W) in water depths from 2.7 m to 12.2 m. The average linear extension per year based on x-radiograph analysis is similar (8.1 and 8.6, ×1.9 mm/yr, 1σ; n=31) for colonies at water depths of 2.7 and 4.3 m, respectively, for the interval from 1963 to 1991. Progressively slower extension rates are observed for deeper colonies (7.6 × 1.8, 7.5 × 1.9, and 4.5 × 1.5 mm/yr, 1σ; n=31) for 5.8, 6.1 and 12.2 m, respectively. Correlation coefficients among annual linear extension records vary between 0.00 and 0.40 (n=31) with the lowest correlation between colonies in close proximity (~1 km) and highest between colonies furthest apart (~250 km). We analyzed coral Sr/Ca at approximately 18 samples per year (0.5 mm/sample) along corallite thecal walls parallel to the slab surface for the interval from 1982 to 1991. This geochemical proxy for SST reveals seasonal variations within the coral skeleton that correspond to the high- and low-density bands in the coral slab, which represent one year of growth. Our linear regression of coral Sr/Ca from a single core (5.8 m water depth) to the Optimum Interpolation sea surface temperature (OISST; Reynolds et al., 2002) results in a slope of -0.049 (×0.024 mmol/mol/°C, 1σ; n=100; r2=0.52), which is slightly greater than the slope of other published Montastraea calibrations, but less than those reported for Porites spp. An alternative calibration method is to examine mean coral Sr/Ca with

  3. Acropora interbranch skeleton Sr/Ca ratios: Evaluation of a potential new high-resolution paleothermometer

    NASA Astrophysics Data System (ADS)

    Sadler, James; Nguyen, Ai D.; Leonard, Nicole D.; Webb, Gregory E.; Nothdurft, Luke D.

    2016-04-01

    The majority of coral geochemistry-based paleoclimate reconstructions in the Indo-Pacific are conducted on selectively cored colonies of massive Porites. This restriction to a single genus may make it difficult to amass the required paleoclimate data for studies that require deep reef coring techniques. Acropora, however, is a highly abundant coral genus in both modern and fossil reef systems and displays potential as a novel climate archive. Here we present a calibration study for Sr/Ca ratios recovered from interbranch skeleton in corymbose Acropora colonies from Heron Reef, southern Great Barrier Reef. Significant intercolony differences in absolute Sr/Ca ratios were normalized by producing anomaly plots of both coral geochemistry and instrumental water temperature records. Weighted linear regression of these anomalies from the lagoon and fore-reef slope provide a sensitivity of -0.05 mmol/mol °C-1, with a correlation coefficient (r2 = 0.65) comparable to those of genera currently used in paleoclimate reconstructions. Reconstructions of lagoon and reef slope mean seasonality in water temperature accurately identify the greater seasonal amplitude observed in the lagoon of Heron Reef. A longer calibration period is, however, required for reliable reconstructions of annual mean water temperatures.

  4. Fast Growth May Impair Regeneration Capacity in the Branching Coral Acropora muricata

    PubMed Central

    Denis, Vianney; Guillaume, Mireille M. M.; Goutx, Madeleine; de Palmas, Stéphane; Debreuil, Julien; Baker, Andrew C.; Boonstra, Roxane K.; Bruggemann, J. Henrich

    2013-01-01

    Regeneration of artificially induced lesions was monitored in nubbins of the branching coral Acropora muricata at two reef-flat sites representing contrasting environments at Réunion Island (21°07′S, 55°32′E). Growth of these injured nubbins was examined in parallel, and compared to controls. Biochemical compositions of the holobiont and the zooxanthellae density were determined at the onset of the experiment, and the photosynthetic efficiency (Fv/Fm) of zooxanthellae was monitored during the experiment. Acropora muricata rapidly regenerated small lesions, but regeneration rates significantly differed between sites. At the sheltered site characterized by high temperatures, temperature variations, and irradiance levels, regeneration took 192 days on average. At the exposed site, characterized by steadier temperatures and lower irradiation, nubbins demonstrated fast lesion repair (81 days), slower growth, lower zooxanthellae density, chlorophyll a concentration and lipid content than at the former site. A trade-off between growth and regeneration rates was evident here. High growth rates seem to impair regeneration capacity. We show that environmental conditions conducive to high zooxanthellae densities in corals are related to fast skeletal growth but also to reduced lesion regeneration rates. We hypothesize that a lowered regenerative capacity may be related to limited availability of energetic and cellular resources, consequences of coral holobionts operating at high levels of photosynthesis and associated growth. PMID:24023627

  5. Contrasting recovery following removal of growth anomalies in the corals Acropora and Montipora.

    PubMed

    Williams, Gareth J

    2013-10-11

    Growth anomalies (GAs) in scleractinian corals drain energy from the host and can result in partial or entire colony mortality. Here I show that growth anomaly removal is an effective treatment for the branching coral Acropora acuminata, with 90% of subjects remaining GA-free 9 mo following the procedure. In contrast, the encrusting coral Montipora efflorescens did not respond positively to treatment, with GAs re-developing in 100% of treated subjects. There was no clear evidence that injuries sustained during GA removal increased susceptibility to GA development in either coral species. Based on these results, I hypothesize that the factors inducing GAs in Acropora acuminata are localized, whereas those in Montipora efflorescens appear more systemic throughout the colony-perhaps the result of a genetically-based factor, or a persistent causative agent such as a virus. GA removal may therefore be effective for targeted rescues of particular coral species and morphologies in reef systems with low overall disease prevalence and is likely to be most effective for scleractinian corals if complimented by management actions that address the ultimate drivers of GAs on coral reefs. PMID:24113251

  6. Diurnal and nocturnal transcriptomic variation in the Caribbean staghorn coral, Acropora cervicornis.

    PubMed

    Hemond, Elizabeth M; Vollmer, Steven V

    2015-09-01

    Reef-building corals experience large diel shifts in their environment, both externally due to changes in light intensity, predator activity and prey availability, and internally as a result of diel fluctuations in photosynthesis by their endosymbiotic algae, Symbiodinium. Diel patterns of tentacle behaviour, skeletal growth and gene expression indicate reactions of the coral animal in response to light and through circadian regulation. Some corals, such as the Caribbean Acroporas, have strong within-colony division of labour, including specialized fast-growing apical polyps, accompanied by large gene expression differences. Here we use RNA-seq to evaluate how diel changes in gene expression vary within the branching Caribbean staghorn coral, Acropora cervicornis, between branch tips and branch bases. Multifactor generalized linear model analysis indicated that 6% (3005) of transcripts were differentially expressed between branch tips and bases, while 1% (441) of transcripts were differentially expressed between day and night. The gene expression patterns of 220 transcripts were affected by both time of day and location within the colony. In particular, photoreceptors, putative circadian genes, stress response genes and metabolic genes were differentially expressed between day and night, and some of these, including Amcry1, tef and hebp2, exhibited location-specific regulation within the coral colony as well. These findings indicate that the genetic response of the coral to day and night conditions varies within the colony. Both time of day and location within the colony are factors that should be considered in future coral gene expression experiments. PMID:26184385

  7. Bacterial communities associated with healthy and Acropora white syndrome-affected corals from American Samoa

    USGS Publications Warehouse

    Wilson, Bryan; Aeby, Greta S.; Work, Thierry M.; Bourne, David G.

    2012-01-01

    Acropora white syndrome (AWS) is characterized by rapid tissue loss revealing the white underlying skeleton and affects corals worldwide; however, reports of causal agents are conflicting. Samples were collected from healthy and diseased corals and seawater around American Samoa and bacteria associated with AWS characterized using both culture-dependent and culture-independent methods, from coral mucus and tissue slurries, respectively. Bacterial 16S rRNA gene clone libraries derived from coral tissue were dominated by the Gammaproteobacteria, and Jaccard's distances calculated between the clone libraries showed that those from diseased corals were more similar to each other than to those from healthy corals. 16S rRNA genes from 78 culturable coral mucus isolates also revealed a distinct partitioning of bacterial genera into healthy and diseased corals. Isolates identified as Vibrionaceae were further characterized by multilocus sequence typing, revealing that whilst several Vibrio spp. were found to be associated with AWS lesions, a recently described species, Vibrio owensii, was prevalent amongst cultured Vibrio isolates. Unaffected tissues from corals with AWS had a different microbiota than normal Acropora as found by others. Determining whether a microbial shift occurs prior to disease outbreaks will be a useful avenue of pursuit and could be helpful in detecting prodromal signs of coral disease prior to manifestation of lesions.

  8. The reproductive seasonality and gametogenic cycle of Acropora cervicornis off Broward County, Florida, USA

    NASA Astrophysics Data System (ADS)

    Vargas-Ángel, Bernardo; Colley, Susan B.; Hoke, S. Michael; Thomas, James D.

    2006-03-01

    Reproductive characters of the Caribbean reef-building coral Acropora cervicornis were investigated based on histological samples collected from April 2001 through October 2002. Oogenesis commenced in early to mid-October through November and spermatogenesis was initiated from January to March. The onset of gametogenesis was staggered, exhibiting up to approximately a 1-month delay within colonies. In the hermaphroditic polyps, the observed male-to-female gonad ratio was nearly 1:1 and ripe oocytes represented over 70% of the total gonadal volume. Fecundity estimates based on Stage IV ova ranged between 10.4 and 21.8 mm3 per square centimeter per year, comparable to A. cervicornis in Puerto Rico and other broadcasting Indo-Pacific Acropora. Fecundity estimates based on Stage III vitellogenic oocytes indicated statistically significant differences among study sites. Spawning in field conditions was observed in 2001, 2003, and 2004 from 2300 to 2330 h. Gamete release generally occurred synchronously between nights two and seven after the full moon of July or August. However in 2003, multiple, small-scale gamete release episodes occurred over more than one lunar cycle. This coincided with the full moon occurring early in the month of July. While prolific gamete production is reported in this study, low levels of recruitment have been reported for this species. Thus, the highly fragmenting A. cervicornis may rely heavily on asexual reproduction for population maintenance and expansion, and recovery after disturbance may be greatly protracted.

  9. Selective Impact of Disease on Coral Communities: Outbreak of White Syndrome Causes Significant Total Mortality of Acropora Plate Corals

    PubMed Central

    Hobbs, Jean-Paul A.; Frisch, Ashley J.; Newman, Stephen J.; Wakefield, Corey B.

    2015-01-01

    Coral diseases represent a significant and increasing threat to coral reefs. Among the most destructive diseases is White Syndrome (WS), which is increasing in distribution and prevalence throughout the Indo-Pacific. The aim of this study was to determine taxonomic and spatial patterns in mortality rates of corals following the 2008 outbreak of WS at Christmas Island in the eastern Indian Ocean. WS mainly affected Acropora plate corals and caused total mortality of 36% of colonies across all surveyed sites and depths. Total mortality varied between sites but was generally much greater in the shallows (0–96% of colonies at 5 m depth) compared to deeper waters (0–30% of colonies at 20 m depth). Site-specific mortality rates were a reflection of the proportion of corals affected by WS at each site during the initial outbreak and were predicted by the initial cover of live Acropora plate cover. The WS outbreak had a selective impact on the coral community. Following the outbreak, live Acropora plate coral cover at 5 m depth decreased significantly from 7.0 to 0.8%, while the cover of other coral taxa remained unchanged. Observations five years after the initial outbreak revealed that total Acropora plate cover remained low and confirmed that corals that lost all their tissue due to WS did not recover. These results demonstrate that WS represents a significant and selective form of coral mortality and highlights the serious threat WS poses to coral reefs in the Indo-Pacific. PMID:26147291

  10. Two functionally distinct ciliates dwelling in Acropora corals in the South China Sea near Sanya, Hainan Province, China.

    PubMed

    Qiu, Dajun; Huang, Liangmin; Huang, Hui; Yang, Jianhui; Lin, Senjie

    2010-08-01

    We detected and characterized two distinct scuticociliate ciliates inside Acropora corals in the South China Sea. One, voraciously foraging on Symbiodinium, resembled the brown band disease of ciliates. The other, which is closely related to Paranophrys magna, grazed on detritus instead of Symbiodinium. These two ciliates may serve contrasting functions (competitor versus "cleaner") in the coral-ciliate-Symbiodinium triangular relationship.

  11. Selective Impact of Disease on Coral Communities: Outbreak of White Syndrome Causes Significant Total Mortality of Acropora Plate Corals.

    PubMed

    Hobbs, Jean-Paul A; Frisch, Ashley J; Newman, Stephen J; Wakefield, Corey B

    2015-01-01

    Coral diseases represent a significant and increasing threat to coral reefs. Among the most destructive diseases is White Syndrome (WS), which is increasing in distribution and prevalence throughout the Indo-Pacific. The aim of this study was to determine taxonomic and spatial patterns in mortality rates of corals following the 2008 outbreak of WS at Christmas Island in the eastern Indian Ocean. WS mainly affected Acropora plate corals and caused total mortality of 36% of colonies across all surveyed sites and depths. Total mortality varied between sites but was generally much greater in the shallows (0-96% of colonies at 5 m depth) compared to deeper waters (0-30% of colonies at 20 m depth). Site-specific mortality rates were a reflection of the proportion of corals affected by WS at each site during the initial outbreak and were predicted by the initial cover of live Acropora plate cover. The WS outbreak had a selective impact on the coral community. Following the outbreak, live Acropora plate coral cover at 5 m depth decreased significantly from 7.0 to 0.8%, while the cover of other coral taxa remained unchanged. Observations five years after the initial outbreak revealed that total Acropora plate cover remained low and confirmed that corals that lost all their tissue due to WS did not recover. These results demonstrate that WS represents a significant and selective form of coral mortality and highlights the serious threat WS poses to coral reefs in the Indo-Pacific.

  12. Restoration of coral populations in light of genetic diversity estimates

    PubMed Central

    Porto, I.; Zubillaga, A. L.

    2012-01-01

    Due to the importance of preserving the genetic integrity of populations, strategies to restore damaged coral reefs should attempt to retain the allelic diversity of the disturbed population; however, genetic diversity estimates are not available for most coral populations. To provide a generalized estimate of genetic diversity (in terms of allelic richness) of scleractinian coral populations, the literature was surveyed for studies describing the genetic structure of coral populations using microsatellites. The mean number of alleles per locus across 72 surveyed scleractinian coral populations was 8.27 (±0.75 SE). In addition, population genetic datasets from four species (Acropora palmata, Montastraea cavernosa, Montastraea faveolata and Pocillopora damicornis) were analyzed to assess the minimum number of donor colonies required to retain specific proportions of the genetic diversity of the population. Rarefaction analysis of the population genetic datasets indicated that using 10 donor colonies randomly sampled from the original population would retain >50% of the allelic diversity, while 35 colonies would retain >90% of the original diversity. In general, scleractinian coral populations are genetically diverse and restoration methods utilizing few clonal genotypes to re-populate a reef will diminish the genetic integrity of the population. Coral restoration strategies using 10–35 randomly selected local donor colonies will retain at least 50–90% of the genetic diversity of the original population. PMID:22833700

  13. Restoration of coral populations in light of genetic diversity estimates

    NASA Astrophysics Data System (ADS)

    Shearer, T. L.; Porto, I.; Zubillaga, A. L.

    2009-09-01

    Due to the importance of preserving the genetic integrity of populations, strategies to restore damaged coral reefs should attempt to retain the allelic diversity of the disturbed population; however, genetic diversity estimates are not available for most coral populations. To provide a generalized estimate of genetic diversity (in terms of allelic richness) of scleractinian coral populations, the literature was surveyed for studies describing the genetic structure of coral populations using microsatellites. The mean number of alleles per locus across 72 surveyed scleractinian coral populations was 8.27 (±0.75 SE). In addition, population genetic datasets from four species ( Acropora palmata, Montastraea cavernosa, Montastraea faveolata and Pocillopora damicornis) were analyzed to assess the minimum number of donor colonies required to retain specific proportions of the genetic diversity of the population. Rarefaction analysis of the population genetic datasets indicated that using 10 donor colonies randomly sampled from the original population would retain >50% of the allelic diversity, while 35 colonies would retain >90% of the original diversity. In general, scleractinian coral populations are genetically diverse and restoration methods utilizing few clonal genotypes to re-populate a reef will diminish the genetic integrity of the population. Coral restoration strategies using 10-35 randomly selected local donor colonies will retain at least 50-90% of the genetic diversity of the original population.

  14. Transcriptomic responses to darkness stress point to common coral bleaching mechanisms

    NASA Astrophysics Data System (ADS)

    Desalvo, M. K.; Estrada, A.; Sunagawa, S.; Medina, Mónica

    2012-03-01

    Coral bleaching occurs in response to numerous abiotic stressors, the ecologically most relevant of which is hyperthermic stress due to increasing seawater temperatures. Bleaching events can span large geographic areas and are currently a salient threat to coral reefs worldwide. Much effort has been focused on understanding the molecular and cellular events underlying bleaching, and these studies have mainly utilized heat and light stress regimes. In an effort to determine whether different stressors share common bleaching mechanisms, we used complementary DNA (cDNA) microarrays for the corals Acropora palmata and Montastraea faveolata (containing >10,000 features) to measure differential gene expression during darkness stress. Our results reveal a striking transcriptomic response to darkness in A. palmata involving chaperone and antioxidant up-regulation, growth arrest, and metabolic modifications. As these responses were previously measured during thermal stress, our results suggest that different stressors may share common bleaching mechanisms. Furthermore, our results point to hypoxia and endoplasmic reticulum stress as critical cellular events involved in molecular bleaching mechanisms. On the other hand, we identified a meager transcriptomic response to darkness in M. faveolata where gene expression differences between host colonies and sampling locations were greater than differences between control and stressed fragments. This and previous coral microarray studies reveal the immense range of transcriptomic responses that are possible when studying two coral species that differ greatly in their ecophysiology, thus pointing to the importance of comparative approaches in forecasting how corals will respond to future environmental change.

  15. Magnesium content within the skeletal architecture of the coral Montastraea faveolata: locations of brucite precipitation and implications to fine-scale data fluctuations

    USGS Publications Warehouse

    Buster, N.A.; Holmes, C.W.

    2006-01-01

    Small portions of coral cores were analyzed using a high-resolution laser ablation inductively coupled plasma mass spectrometer (LA ICP-MS) to determine the geochemical signatures within and among specific skeletal structures in the large framework coral, Montastraea faveolata. Vertical transects were sampled along three parallel skeletal structures: endothecal (septal flank), corallite wall, and exothecal (costal flank) areas. The results demonstrate that trace element levels varied among the three structures. Magnesium (Mg) varied among adjacent structures and was most abundant within the exothecal portion of the skeleton. Scanning electron microscopy (SEM) revealed the presence of hexagonal crystals forming thick discs, pairs or doublets of individual crystals, and rosettes in several samples. High Mg within these crystals was confirmed with energy dispersive spectroscopy (EDS), infrared spectrometry, and LA ICP-MS. The chemical composition is consistent with the mineral brucite [Mg(OH2)]. These crystals are located exclusively in the exothecal area of the skeleton, are often associated with green endolithic algae, and are commonly associated with increased Mg levels found in the adjacent corallite walls. Although scattered throughout the exothecal, the brucite crystals are concentrated within green bands where levels of Mg increase substantially relative to other portions of the skeleton. The presence and locations of high-Mg crystals may explain the fine-scale fluctuations in Mg data researchers have been questioning for years.

  16. Chromera velia is endosymbiotic in larvae of the reef corals Acropora digitifera and A. tenuis.

    PubMed

    Cumbo, Vivian R; Baird, Andrew H; Moore, Robert B; Negri, Andrew P; Neilan, Brett A; Salih, Anya; van Oppen, Madeleine J H; Wang, Yan; Marquis, Christopher P

    2013-03-01

    Scleractinian corals occur in symbiosis with a range of organisms including the dinoflagellate alga, Symbiodinium, an association that is mutualistic. However, not all symbionts benefit the host. In particular, many organisms within the microbial mucus layer that covers the coral epithelium can cause disease and death. Other organisms in symbiosis with corals include the recently described Chromera velia, a photosynthetic relative of the apicomplexan parasites that shares a common ancestor with Symbiodinium. To explore the nature of the association between C. velia and corals we first isolated C. velia from the coral Montipora digitata and then exposed aposymbiotic Acropora digitifera and A. tenuis larvae to these cultures. Three C. velia cultures were isolated, and symbiosis was established in coral larvae of both these species exposed to all three clones. Histology verified that C. velia was located in the larval endoderm and ectoderm. These results indicate that C. velia has the potential to be endosymbiotic with coral larvae.

  17. Chromera velia is endosymbiotic in larvae of the reef corals Acropora digitifera and A. tenuis.

    PubMed

    Cumbo, Vivian R; Baird, Andrew H; Moore, Robert B; Negri, Andrew P; Neilan, Brett A; Salih, Anya; van Oppen, Madeleine J H; Wang, Yan; Marquis, Christopher P

    2013-03-01

    Scleractinian corals occur in symbiosis with a range of organisms including the dinoflagellate alga, Symbiodinium, an association that is mutualistic. However, not all symbionts benefit the host. In particular, many organisms within the microbial mucus layer that covers the coral epithelium can cause disease and death. Other organisms in symbiosis with corals include the recently described Chromera velia, a photosynthetic relative of the apicomplexan parasites that shares a common ancestor with Symbiodinium. To explore the nature of the association between C. velia and corals we first isolated C. velia from the coral Montipora digitata and then exposed aposymbiotic Acropora digitifera and A. tenuis larvae to these cultures. Three C. velia cultures were isolated, and symbiosis was established in coral larvae of both these species exposed to all three clones. Histology verified that C. velia was located in the larval endoderm and ectoderm. These results indicate that C. velia has the potential to be endosymbiotic with coral larvae. PMID:23063731

  18. Calcification and photosynthesis of the coral acropora cervicornis under calcium limited conditions

    NASA Technical Reports Server (NTRS)

    Rathfon, Megan; Brewer, Debbie

    1997-01-01

    Differing hypothesis about the function of calcification are based on an interesting dilemma. Is the purpose of calcification mainly a structural and protective one or does calcification serve other functions? Does photosynthesis increase carbonate ion activity and cause calcification or does calcification increase CO2 levels and stimulate photsynthesis? It is proposed that calcification in corals is not dependent upon photosynthesis but upon calcium levels in the water. Under normal ocean conditions, corals convert a certain percentage of energy to photosynthesis and respiration and another percentage to calcification. As corals become nutrient stressed, particularly calcium limited, the ratio of photosynthesis to calcification shifts towards calcification in order to generate protons. The protons generated during calcification may stimulate photosynthesis and aid in the uptake of nutrients and biocarbonates. The results of the calcification experiment show a trend towards increased calcification and decreased photosynthesis when the coral Acropora cervicornis is calcium limited, but the data are inconclusive and further research is needed.

  19. The Skeleton of the Staghorn Coral Acropora millepora: Molecular and Structural Characterization

    PubMed Central

    Ramos-Silva, Paula; Kaandorp, Jaap; Herbst, Frédéric; Plasseraud, Laurent; Alcaraz, Gérard; Stern, Christine; Corneillat, Marion; Guichard, Nathalie; Durlet, Christophe; Luquet, Gilles; Marin, Frédéric

    2014-01-01

    The scleractinian coral Acropora millepora is one of the most studied species from the Great Barrier Reef. This species has been used to understand evolutionary, immune and developmental processes in cnidarians. It has also been subject of several ecological studies in order to elucidate reef responses to environmental changes such as temperature rise and ocean acidification (OA). In these contexts, several nucleic acid resources were made available. When combined to a recent proteomic analysis of the coral skeletal organic matrix (SOM), they enabled the identification of several skeletal matrix proteins, making A. millepora into an emerging model for biomineralization studies. Here we describe the skeletal microstructure of A. millepora skeleton, together with a functional and biochemical characterization of its occluded SOM that focuses on the protein and saccharidic moieties. The skeletal matrix proteins show a large range of isoelectric points, compositional patterns and signatures. Besides secreted proteins, there are a significant number of proteins with membrane attachment sites such as transmembrane domains and GPI anchors as well as proteins with integrin binding sites. These features show that the skeletal proteins must have strong adhesion properties in order to function in the calcifying space. Moreover this data suggest a molecular connection between the calcifying epithelium and the skeletal tissue during biocalcification. In terms of sugar moieties, the enrichment of the SOM in arabinose is striking, and the monosaccharide composition exhibits the same signature as that of mucus of acroporid corals. Finally, we observe that the interaction of the acetic acid soluble SOM on the morphology of in vitro grown CaCO3 crystals is very pronounced when compared with the calcifying matrices of some mollusks. In light of these results, we wish to commend Acropora millepora as a model for biocalcification studies in scleractinians, from molecular and structural

  20. Potential spawn induction and suppression agents in Caribbean Acropora cervicornis corals of the Florida Keys.

    PubMed

    Flint, Mark; Than, John T

    2016-01-01

    The enhanced ability to direct sexual reproduction may lead to improved restoration outcomes for Acropora cervicornis. Gravid fragments of A. cervicornis were maintained in a laboratory for two sequential trials in the seven days prior to natural spawning in the Florida Keys. Ten replicates of five chemicals known to affect spawning in various invertebrate taxa were tested. Hydrogen peroxide at 2 mM (70%) and L-5-hydroxytryptophan (5-HTP) at 5 (40%) and 20 µM (30%) induced spawning within 15.4 h, 38.8 h and 26.9 h of dosing at or above the rate of release of the control (30%) within 14.6 h. Serotonin acetate monohydrate at 1 µM (20%) and 10 µM (20%), naloxone hydrochloride dihydrate at 0.01 µM (10%) and potassium phosphate monobasic at 0.25 µM (0%) induced spawning at rates less than the control. Although the greatest number of fragments spawned using hydrogen peroxide, it was with 100% mortality. There was a significantly higher induction rate closer to natural spawn (Trial 2) compared with Trial 1 and no genotype effect. Mechanisms of action causing gamete release were not elucidated. In Caribbean staghorn corals, 5-HTP shows promise as a spawning induction agent if administered within 72 h of natural spawn and it will not result in excessive mortality. Phosphate chemicals may inhibit spawning. This is the first study of its kind on Caribbean acroporid corals and may offer an important conservation tool for biologists currently charged with restoring the imperiled Acropora reefs of the Florida Keys. PMID:27168990

  1. Potential spawn induction and suppression agents in Caribbean Acropora cervicornis corals of the Florida Keys

    PubMed Central

    Than, John T.

    2016-01-01

    The enhanced ability to direct sexual reproduction may lead to improved restoration outcomes for Acropora cervicornis. Gravid fragments of A. cervicornis were maintained in a laboratory for two sequential trials in the seven days prior to natural spawning in the Florida Keys. Ten replicates of five chemicals known to affect spawning in various invertebrate taxa were tested. Hydrogen peroxide at 2 mM (70%) and L-5-hydroxytryptophan (5-HTP) at 5 (40%) and 20 µM (30%) induced spawning within 15.4 h, 38.8 h and 26.9 h of dosing at or above the rate of release of the control (30%) within 14.6 h. Serotonin acetate monohydrate at 1 µM (20%) and 10 µM (20%), naloxone hydrochloride dihydrate at 0.01 µM (10%) and potassium phosphate monobasic at 0.25 µM (0%) induced spawning at rates less than the control. Although the greatest number of fragments spawned using hydrogen peroxide, it was with 100% mortality. There was a significantly higher induction rate closer to natural spawn (Trial 2) compared with Trial 1 and no genotype effect. Mechanisms of action causing gamete release were not elucidated. In Caribbean staghorn corals, 5-HTP shows promise as a spawning induction agent if administered within 72 h of natural spawn and it will not result in excessive mortality. Phosphate chemicals may inhibit spawning. This is the first study of its kind on Caribbean acroporid corals and may offer an important conservation tool for biologists currently charged with restoring the imperiled Acropora reefs of the Florida Keys. PMID:27168990

  2. The skeleton of the staghorn coral Acropora millepora: molecular and structural characterization.

    PubMed

    Ramos-Silva, Paula; Kaandorp, Jaap; Herbst, Frédéric; Plasseraud, Laurent; Alcaraz, Gérard; Stern, Christine; Corneillat, Marion; Guichard, Nathalie; Durlet, Christophe; Luquet, Gilles; Marin, Frédéric

    2014-01-01

    The scleractinian coral Acropora millepora is one of the most studied species from the Great Barrier Reef. This species has been used to understand evolutionary, immune and developmental processes in cnidarians. It has also been subject of several ecological studies in order to elucidate reef responses to environmental changes such as temperature rise and ocean acidification (OA). In these contexts, several nucleic acid resources were made available. When combined to a recent proteomic analysis of the coral skeletal organic matrix (SOM), they enabled the identification of several skeletal matrix proteins, making A. millepora into an emerging model for biomineralization studies. Here we describe the skeletal microstructure of A. millepora skeleton, together with a functional and biochemical characterization of its occluded SOM that focuses on the protein and saccharidic moieties. The skeletal matrix proteins show a large range of isoelectric points, compositional patterns and signatures. Besides secreted proteins, there are a significant number of proteins with membrane attachment sites such as transmembrane domains and GPI anchors as well as proteins with integrin binding sites. These features show that the skeletal proteins must have strong adhesion properties in order to function in the calcifying space. Moreover this data suggest a molecular connection between the calcifying epithelium and the skeletal tissue during biocalcification. In terms of sugar moieties, the enrichment of the SOM in arabinose is striking, and the monosaccharide composition exhibits the same signature as that of mucus of acroporid corals. Finally, we observe that the interaction of the acetic acid soluble SOM on the morphology of in vitro grown CaCO3 crystals is very pronounced when compared with the calcifying matrices of some mollusks. In light of these results, we wish to commend Acropora millepora as a model for biocalcification studies in scleractinians, from molecular and structural

  3. Potential spawn induction and suppression agents in Caribbean Acropora cervicornis corals of the Florida Keys.

    PubMed

    Flint, Mark; Than, John T

    2016-01-01

    The enhanced ability to direct sexual reproduction may lead to improved restoration outcomes for Acropora cervicornis. Gravid fragments of A. cervicornis were maintained in a laboratory for two sequential trials in the seven days prior to natural spawning in the Florida Keys. Ten replicates of five chemicals known to affect spawning in various invertebrate taxa were tested. Hydrogen peroxide at 2 mM (70%) and L-5-hydroxytryptophan (5-HTP) at 5 (40%) and 20 µM (30%) induced spawning within 15.4 h, 38.8 h and 26.9 h of dosing at or above the rate of release of the control (30%) within 14.6 h. Serotonin acetate monohydrate at 1 µM (20%) and 10 µM (20%), naloxone hydrochloride dihydrate at 0.01 µM (10%) and potassium phosphate monobasic at 0.25 µM (0%) induced spawning at rates less than the control. Although the greatest number of fragments spawned using hydrogen peroxide, it was with 100% mortality. There was a significantly higher induction rate closer to natural spawn (Trial 2) compared with Trial 1 and no genotype effect. Mechanisms of action causing gamete release were not elucidated. In Caribbean staghorn corals, 5-HTP shows promise as a spawning induction agent if administered within 72 h of natural spawn and it will not result in excessive mortality. Phosphate chemicals may inhibit spawning. This is the first study of its kind on Caribbean acroporid corals and may offer an important conservation tool for biologists currently charged with restoring the imperiled Acropora reefs of the Florida Keys.

  4. Diseases and partial mortality in Montastraea annularis species complex in reefs with differing environmental conditions (NW Caribbean and Gulf of Mexico).

    PubMed

    Jordán-Dahlgren, Eric; Maldonado, Miguel Angel; Rodríguez-Martínez, Rosa Elisa

    2005-01-25

    We documented the prevalence of diseases, syndromes and partial mortality in colonies of the Montastraea annularis species complex on 3 reefs, and tested the assumption that a higher prevalence of these parameters occurs when reefs are closer to point-sources of pollution. One reef was isolated from the impact of local factors with the exception of fishing, 1 potentially influenced by local industrial pollutants, and 1 influenced by local urban pollution. Two reefs were surveyed in 1996 and again in 2001 and 1 in 1998 and again in 2001. In 2001, colonies on all reefs had a high prevalence of the yellow-band syndrome and a relatively high degree of recent partial mortality, while the prevalence of black-band and white-plague diseases was low although a new sign, that we named the thin dark line, had relatively high prevalence in all reefs. As no direct relationship was found between disease prevalence and local environmental quality, our results open the possibility that regional and/or global factors may already be playing an important role in the prevalence of coral disease in the Caribbean, and contradict the theory that coral disease prevalence is primarily related to local environmental degradation. Reasons that may partially explain these findings are the high level of potential pathogen connectivity within the Caribbean as a result of its circulation patterns coupled to the large land-derived pollutants and pathogens input into this Mediterranean sea, together with the surface water warming effects which stress corals and enhance pathogen activity.

  5. Cross-amplification and characterization of microsatellite loci in Acropora austera from the south-western Indian Ocean.

    PubMed

    Montoya-Maya, P H; Macdonald, A H H; Schleyer, M H

    2014-02-27

    Here, we report the successful cross-species amplification of previously published acroporid microsatellite markers in the coral Acropora austera from the south-western Indian Ocean. This fast-growing species is a major reef-building coral on South African reefs; however, it is the most damaged coral by scuba diving activity, and is known to be very susceptible to coral bleaching. Neither genetic information nor symbiont-free host tissue was available to develop novel microsatellite markers for this species. Cross-species amplification of previously published microsatellite markers was considered as an alternative to overcome these problems. Of the 21 microsatellite markers tested, 6 were reliably amplified, scored, and found to contain polymorphic loci (3-15 alleles). Although microsatellite sequences are believed to be scarce in the Acropora genome because of its small size, the results of this study and previous research indicate that the microsatellite sequences are well conserved across Acropora species. A detailed screening process identified and quantified the sources of error and bias in the application of these markers (e.g., allele scoring error, failure rates, frequency of null alleles), and may be accounted for in the study of the contemporary gene flow of A. austera in the south-western Indian Ocean.

  6. Cross-amplification and characterization of microsatellite loci in Acropora austera from the south-western Indian Ocean.

    PubMed

    Montoya-Maya, P H; Macdonald, A H H; Schleyer, M H

    2014-01-01

    Here, we report the successful cross-species amplification of previously published acroporid microsatellite markers in the coral Acropora austera from the south-western Indian Ocean. This fast-growing species is a major reef-building coral on South African reefs; however, it is the most damaged coral by scuba diving activity, and is known to be very susceptible to coral bleaching. Neither genetic information nor symbiont-free host tissue was available to develop novel microsatellite markers for this species. Cross-species amplification of previously published microsatellite markers was considered as an alternative to overcome these problems. Of the 21 microsatellite markers tested, 6 were reliably amplified, scored, and found to contain polymorphic loci (3-15 alleles). Although microsatellite sequences are believed to be scarce in the Acropora genome because of its small size, the results of this study and previous research indicate that the microsatellite sequences are well conserved across Acropora species. A detailed screening process identified and quantified the sources of error and bias in the application of these markers (e.g., allele scoring error, failure rates, frequency of null alleles), and may be accounted for in the study of the contemporary gene flow of A. austera in the south-western Indian Ocean. PMID:24634181

  7. Linear extension rates and gross carbonate production of Acropora cervicornis at Coral Gardens, Belize.

    NASA Astrophysics Data System (ADS)

    Peeling, E.; Greer, L.; Lescinsky, H.; Humston, R.; Wirth, K. R.; Baums, I. B.; Curran, A.

    2014-12-01

    Branching Acropora coral species have fast growth and carbonate production rates, and thus have functioned as important reef-building species throughout the Pleistocene and Holocene. Recently, net carbonate production (kg CaCO3 m-2 year-1) has been recognized as an important measure of reef health, especially when monitoring endangered species, such as Acropora cervicornis. This study examines carbonate production in a thriving population of A. cervicornis at the Coral Gardens reef in Belize. Photographic surveys were conducted along five transects of A. cervicornis-dominated reefs from 2011-2014. Matching photographs from 2013 and 2014 were scaled to 1 m2 and compared to calculate 84 individual A. cervicornis linear extension rates across the reef. Linear extension rates averaged 12.4 cm/yr and were as high as 17 cm/yr in some areas of the reef. Carbonate production was calculated two ways. The first followed the standard procedure of multiplying percent live coral cover, by the linear extension rate and skeletal density. The second used the number of live coral tips per square meter in place of percent live coral multiplied by the average cross-sectional area of the branches. The standard method yielded a carbonate production rate of 113 kg CaCO3 m-2 year-1 for the reef, and the tip method yielded a rate of 6 kg m-2 year-1. We suggest that the tip method is a more accurate measure of production, because A. cervicornis grows primarily from the live tips, with only limited radial growth and resheeting over dead skeleton. While this method omits the contributions of radial growth and resheeting, and is therefore somewhat of an underestimate, our future work will quantify these aspects of growth in a more complete carbonate budget. Still, our estimate suggests a carbonate production rate per unit area of A. cervicornis that is on par with other Caribbean coral species, rather than two orders of magnitude higher as reported by Perry et al (2013). Although gross coral

  8. Population genetic structure between Yap and Palau for the coral Acropora hyacinthus

    PubMed Central

    Cros, Annick; Toonen, Robert J.; Davies, Sarah W.

    2016-01-01

    Information on connectivity is becoming increasingly in demand as marine protected areas are being designed as an integral part of a network to protect marine resources at the ecosystem level. Larval dispersal and population structure, however, remain very difficult to assess. Here, we tested the predictions of a detailed oceanographic connectivity model of larval dispersal and coral recruitment within Palau and between Palau and Yap, which was developed to support the review of the existing network of marine protected areas in Palau. We used high throughput microsatellite genotyping of the coral Acropora hyacinthus to characterize population genetic structure. Pairwise F′ST values between Palau and Yap (0.10), Palau and Ngulu (0.09) and Yap and Ngulu (0.09) were all significant and similar to pairwise F′ST values of sites within Palau (0.02–0.12) and within Yap (0.02–0.09) highlighting structure at island scale and indicating that recruitment may be even more localized than previously anticipated. A bottleneck test did not reveal any signs of a founder effect between Yap and Palau. Overall, the data supports the idea that recovery of A. hyacinthus in Palau did not come exclusively from a single source but most likely came from a combination of areas, including sites within Palau. In light of these results there seems to be very little connectivity around the barrier reef and management recommendation would be to increase the number or the size of MPAs within Palau.

  9. Symbiodinium clades A and D differentially predispose Acropora cytherea to disease and Vibrio spp. colonization.

    PubMed

    Rouzé, Héloïse; Lecellier, Gaël; Saulnier, Denis; Berteaux-Lecellier, Véronique

    2016-01-01

    Coral disease outbreaks have increased over the last three decades, but their causal agents remain mostly unclear (e.g., bacteria, viruses, fungi, protists). This study details a 14-month-long survey of coral colonies in which observations of the development of disease was observed in nearly half of the sampled colonies. A bimonthly qPCR method was used to quantitatively and qualitatively evaluate Symbiodinium assemblages of tagged colonies, and to detect the presence of Vibrio spp. Firstly, our data showed that predisposition to disease development in general, and, more specifically, infection by Vibrio spp. in Acropora cytherea depended on which clades of Symbiodinium were harbored. In both cases, harboring clade D rather than A was beneficial to the coral host. Secondly, the detection of Vibrio spp. in only colonies that developed disease strongly suggests opportunistic traits of the bacteria. Finally, even if sporadic cases of switching and probably shuffling were observed, this long-term survey does not suggest specific-clade recruitment in response to stressors. Altogether, our results demonstrate that the fitness of the coral holobiont depends on its initial consortium of Symbiodinium, which is distinct among colonies, rather than a temporary adaptation achieved through acquiring different Symbiodinium clades. PMID:26843939

  10. Population genetic structure between Yap and Palau for the coral Acropora hyacinthus.

    PubMed

    Cros, Annick; Toonen, Robert J; Davies, Sarah W; Karl, Stephen A

    2016-01-01

    Information on connectivity is becoming increasingly in demand as marine protected areas are being designed as an integral part of a network to protect marine resources at the ecosystem level. Larval dispersal and population structure, however, remain very difficult to assess. Here, we tested the predictions of a detailed oceanographic connectivity model of larval dispersal and coral recruitment within Palau and between Palau and Yap, which was developed to support the review of the existing network of marine protected areas in Palau. We used high throughput microsatellite genotyping of the coral Acropora hyacinthus to characterize population genetic structure. Pairwise F' ST values between Palau and Yap (0.10), Palau and Ngulu (0.09) and Yap and Ngulu (0.09) were all significant and similar to pairwise F' ST values of sites within Palau (0.02-0.12) and within Yap (0.02-0.09) highlighting structure at island scale and indicating that recruitment may be even more localized than previously anticipated. A bottleneck test did not reveal any signs of a founder effect between Yap and Palau. Overall, the data supports the idea that recovery of A. hyacinthus in Palau did not come exclusively from a single source but most likely came from a combination of areas, including sites within Palau. In light of these results there seems to be very little connectivity around the barrier reef and management recommendation would be to increase the number or the size of MPAs within Palau. PMID:27602294

  11. Integral Light-Harvesting Complex Expression In Symbiodinium Within The Coral Acropora aspera Under Thermal Stress

    PubMed Central

    Gierz, Sarah L.; Gordon, Benjamin R.; Leggat, William

    2016-01-01

    Coral reef success is largely dependent on the symbiosis between coral hosts and dinoflagellate symbionts belonging to the genus Symbiodinium. Elevated temperatures can result in the expulsion of Symbiodinium or loss of their photosynthetic pigments and is known as coral bleaching. It has been postulated that the expression of light-harvesting protein complexes (LHCs), which bind chlorophylls (chl) and carotenoids, are important in photobleaching. This study explored the effect a sixteen-day thermal stress (increasing daily from 25–34 °C) on integral LHC (chlorophyll a-chlorophyll c2-peridinin protein complex (acpPC)) gene expression in Symbiodinium within the coral Acropora aspera. Thermal stress leads to a decrease in Symbiodinium photosynthetic efficiency by day eight, while symbiont density was significantly lower on day sixteen. Over this time period, the gene expression of five Symbiodinium acpPC genes was quantified. Three acpPC genes exhibited up-regulated expression when corals were exposed to temperatures above 31.5 °C (acpPCSym_1:1, day sixteen; acpPCSym_15, day twelve; and acpPCSym_18, day ten and day sixteen). In contrast, the expression of acpPCSym_5:1 and acpPCSym_10:1 was unchanged throughout the experiment. Interestingly, the three acpPC genes with increased expression cluster together in a phylogenetic analysis of light-harvesting complexes. PMID:27117333

  12. Can benthic algae mediate larval behavior and settlement of the coral Acropora muricata?

    NASA Astrophysics Data System (ADS)

    Denis, V.; Loubeyres, M.; Doo, S. S.; de Palmas, S.; Keshavmurthy, S.; Hsieh, H. J.; Chen, C. A.

    2014-06-01

    The resilience of coral reefs relies significantly on the ability of corals to recover successfully in algal-dominated environments. Larval settlement is a critical but highly vulnerable stage in the early life history of corals. In this study, we analyzed how the presence of two upright fleshy algae, Sargassum mcclurei (SM) and Padina australis (PA), and one crustose coralline algae, Mesophyllum simulans (MS), affects the settlement of Acropora muricata larvae. Coral larvae were exposed to seawater flowing over these algae at two concentrations. Larval settlement and mortality were assessed daily through four variables related to their behavior: swimming, substratum testing, metamorphosis, and stresses. Temperature, dissolved oxygen, pH, algal growth, and photosynthetic efficiency were monitored throughout the experiment. Results showed that A. muricata larvae can settle successfully in the absence of external stimuli (63 ± 6 % of the larvae settled in control treatments). While algae such as MS may stimulate substrate testing and settlement of larvae in the first day after competency, they ultimately had a lower settlement rate than controls. Fleshy algae such as PA, and in a lesser measure SM, induced more metamorphosis than controls and seemed to eventually stimulate settlement. A diverse combination of signals and/or modifications of microenvironments by algae and their associated microbial communities may explain the pattern observed in coral settlement. Overall, this study contributes significantly to the knowledge of the interaction between coral and algae, which is critical for the resilience of the reefs.

  13. Integral Light-Harvesting Complex Expression In Symbiodinium Within The Coral Acropora aspera Under Thermal Stress

    NASA Astrophysics Data System (ADS)

    Gierz, Sarah L.; Gordon, Benjamin R.; Leggat, William

    2016-04-01

    Coral reef success is largely dependent on the symbiosis between coral hosts and dinoflagellate symbionts belonging to the genus Symbiodinium. Elevated temperatures can result in the expulsion of Symbiodinium or loss of their photosynthetic pigments and is known as coral bleaching. It has been postulated that the expression of light-harvesting protein complexes (LHCs), which bind chlorophylls (chl) and carotenoids, are important in photobleaching. This study explored the effect a sixteen-day thermal stress (increasing daily from 25–34 °C) on integral LHC (chlorophyll a-chlorophyll c2-peridinin protein complex (acpPC)) gene expression in Symbiodinium within the coral Acropora aspera. Thermal stress leads to a decrease in Symbiodinium photosynthetic efficiency by day eight, while symbiont density was significantly lower on day sixteen. Over this time period, the gene expression of five Symbiodinium acpPC genes was quantified. Three acpPC genes exhibited up-regulated expression when corals were exposed to temperatures above 31.5 °C (acpPCSym_1:1, day sixteen; acpPCSym_15, day twelve; and acpPCSym_18, day ten and day sixteen). In contrast, the expression of acpPCSym_5:1 and acpPCSym_10:1 was unchanged throughout the experiment. Interestingly, the three acpPC genes with increased expression cluster together in a phylogenetic analysis of light-harvesting complexes.

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  15. Integral Light-Harvesting Complex Expression In Symbiodinium Within The Coral Acropora aspera Under Thermal Stress.

    PubMed

    Gierz, Sarah L; Gordon, Benjamin R; Leggat, William

    2016-01-01

    Coral reef success is largely dependent on the symbiosis between coral hosts and dinoflagellate symbionts belonging to the genus Symbiodinium. Elevated temperatures can result in the expulsion of Symbiodinium or loss of their photosynthetic pigments and is known as coral bleaching. It has been postulated that the expression of light-harvesting protein complexes (LHCs), which bind chlorophylls (chl) and carotenoids, are important in photobleaching. This study explored the effect a sixteen-day thermal stress (increasing daily from 25-34 °C) on integral LHC (chlorophyll a-chlorophyll c2-peridinin protein complex (acpPC)) gene expression in Symbiodinium within the coral Acropora aspera. Thermal stress leads to a decrease in Symbiodinium photosynthetic efficiency by day eight, while symbiont density was significantly lower on day sixteen. Over this time period, the gene expression of five Symbiodinium acpPC genes was quantified. Three acpPC genes exhibited up-regulated expression when corals were exposed to temperatures above 31.5 °C (acpPCSym_1:1, day sixteen; acpPCSym_15, day twelve; and (acpPCSym_18), day ten and day sixteen). In contrast, the expression of acpPCSym_5:1 and acpPCSym_10:1 was unchanged throughout the experiment. Interestingly, the three acpPC genes with increased expression cluster together in a phylogenetic analysis of light-harvesting complexes. PMID:27117333

  16. Population genetic structure between Yap and Palau for the coral Acropora hyacinthus

    PubMed Central

    Cros, Annick; Toonen, Robert J.; Davies, Sarah W.

    2016-01-01

    Information on connectivity is becoming increasingly in demand as marine protected areas are being designed as an integral part of a network to protect marine resources at the ecosystem level. Larval dispersal and population structure, however, remain very difficult to assess. Here, we tested the predictions of a detailed oceanographic connectivity model of larval dispersal and coral recruitment within Palau and between Palau and Yap, which was developed to support the review of the existing network of marine protected areas in Palau. We used high throughput microsatellite genotyping of the coral Acropora hyacinthus to characterize population genetic structure. Pairwise F′ST values between Palau and Yap (0.10), Palau and Ngulu (0.09) and Yap and Ngulu (0.09) were all significant and similar to pairwise F′ST values of sites within Palau (0.02–0.12) and within Yap (0.02–0.09) highlighting structure at island scale and indicating that recruitment may be even more localized than previously anticipated. A bottleneck test did not reveal any signs of a founder effect between Yap and Palau. Overall, the data supports the idea that recovery of A. hyacinthus in Palau did not come exclusively from a single source but most likely came from a combination of areas, including sites within Palau. In light of these results there seems to be very little connectivity around the barrier reef and management recommendation would be to increase the number or the size of MPAs within Palau. PMID:27602294

  17. White syndrome in Acropora muricata: nonspecific bacterial infection and ciliate histophagy.

    PubMed

    Sweet, Michael; Bythell, John

    2015-03-01

    Selective antibiotic treatment of white syndrome (WS)-affected corals (Acropora muricata) from Fiji was used to identify 3 potential bacterial pathogens of the disease. Interestingly, the suite of bacterial associates of the disease was different to that recently identified using identical primer sets for WS on the GBR and in the Solomon Islands. In addition to the three bacterial pathogenic candidates and as previously shown for WS and more recently for white band disease (WBD) in the Caribbean, all samples of the disease were specifically associated with the histophagous ciliate Philaster lucinda. From the pattern of disease progression and histopathology in relation to the selective elimination of microbial groups, we conclude that these 'white' diseases are a result of a nonspecific bacterial infection and a 'secondary' infection by the P. lucinda ciliate. Although we have not observed the initiation of infection, a nonspecific, multispecies bacterial infection appears to be a corequirement for WS lesion progression and we hypothesize that the bacterial infection occurs initially, weakening the defences of the host to predation by the ciliates. Such ciliate histophagy gives rise to the characteristic white band of denuded coral skeleton that gives these diseases their names. The characteristics of the microbial communities of WBD and WS appear identical, and since the bacterial associates of WS vary geographically (and/or temporally), there appears to be no logical distinction between WS in the Indo-Pacific and WBD in the Caribbean.

  18. Unexpected complexity of the Reef-Building Coral Acropora millepora transcription factor network

    PubMed Central

    2011-01-01

    Background Coral reefs are disturbed on a global scale by environmental changes including rising sea surface temperatures and ocean acidification. Little is known about how corals respond or adapt to these environmental changes especially at the molecular level. This is mostly because of the paucity of genome-wide studies on corals and the application of systems approaches that incorporate the latter. Like in any other organism, the response of corals to stress is tightly controlled by the coordinated interplay of many transcription factors. Results Here, we develop and apply a new system-wide approach in order to infer combinatorial transcription factor networks of the reef-building coral Acropora millepora. By integrating sequencing-derived transcriptome measurements, a network of physically interacting transcription factors, and phylogenetic network footprinting we were able to infer such a network. Analysis of the network across a phylogenetically broad sample of five species, including human, reveals that despite the apparent simplicity of corals, their transcription factors repertoire and interaction networks seem to be largely conserved. In addition, we were able to identify interactions among transcription factors that appear to be species-specific lending strength to the novel concept of "Taxonomically Restricted Interactions". Conclusions This study provides the first look at transcription factor networks in corals. We identified a transcription factor repertoire encoded by the coral genome and found consistencies of the domain architectures of transcription factors and conserved regulatory subnetworks across eumetazoan species, providing insight into how regulatory networks have evolved. PMID:21526989

  19. Does dopamine block the spawning of the acroporid coral Acropora tenuis?

    PubMed Central

    Isomura, N.; Yamauchi, C.; Takeuchi, Y.; Takemura, A.

    2013-01-01

    Most corals undergo spawning after a particular moon phase, but how moon-related spawning is endogenously regulated in corals remains unknown. The objective of the present study was to evaluate whether dopamine (DA) affects spawning in Acropora tenuis. When pieces of four A. tenuis colonies were reared under a natural photoperiod and water temperature, spawning was observed after the predicted moon phase. After exposure to water containing DA at 0.1 μM, pieces of the same colonies only released 5 to 10 bundles. Co-treatment with DA and pimozide (D1 and D2 receptors antagonist), but not domperidone (D2 receptor antagonist), induced mass release of bundles from the colonies. A cross-experiment revealed high fertilization rates between the control colonies (95%) and between the control and DA-treated colonies (90%), suggesting that gametes developed normally in coral tissue. Therefore, DA appears to have an inhibitory effect on the spawning of A. tenuis. PMID:24026104

  20. Symbiodinium clades A and D differentially predispose Acropora cytherea to disease and Vibrio spp. colonization.

    PubMed

    Rouzé, Héloïse; Lecellier, Gaël; Saulnier, Denis; Berteaux-Lecellier, Véronique

    2016-01-01

    Coral disease outbreaks have increased over the last three decades, but their causal agents remain mostly unclear (e.g., bacteria, viruses, fungi, protists). This study details a 14-month-long survey of coral colonies in which observations of the development of disease was observed in nearly half of the sampled colonies. A bimonthly qPCR method was used to quantitatively and qualitatively evaluate Symbiodinium assemblages of tagged colonies, and to detect the presence of Vibrio spp. Firstly, our data showed that predisposition to disease development in general, and, more specifically, infection by Vibrio spp. in Acropora cytherea depended on which clades of Symbiodinium were harbored. In both cases, harboring clade D rather than A was beneficial to the coral host. Secondly, the detection of Vibrio spp. in only colonies that developed disease strongly suggests opportunistic traits of the bacteria. Finally, even if sporadic cases of switching and probably shuffling were observed, this long-term survey does not suggest specific-clade recruitment in response to stressors. Altogether, our results demonstrate that the fitness of the coral holobiont depends on its initial consortium of Symbiodinium, which is distinct among colonies, rather than a temporary adaptation achieved through acquiring different Symbiodinium clades.

  1. Dynamics of bacterial community development in the reef coral Acropora muricata following experimental antibiotic treatment

    NASA Astrophysics Data System (ADS)

    Sweet, M. J.; Croquer, A.; Bythell, J. C.

    2011-12-01

    Development of the bacterial community associated with the coral Acropora muricata (= formosa) was monitored using 16S rRNA gene-based techniques and abundance counts over time following experimental modification of the existing microbial community using the antibiotic ciprofloxacin. Abundance of bacteria was reduced >99% by the treatment, resulting in significant changes in bacterial community structure. Following redeployment to their natural environment, some settlement and re-growth of bacteria took place within a few hours, including ribosomal types that were not present, or in low abundance, in the natural microbiota. However, complete recovery of the bacterial community required longer than 96 h, which indicates a relatively slow settlement and growth of bacteria from the water column and suggests that turnover of the natural community is similarly slow. The early developing community was dominated by antibiotic-resistant bacteria from the natural microbiota that survived the treatment and proliferated in the absence of natural competitors, but also included some non-resident ribotypes colonizing from the water column. Almost, all these opportunists were significantly reduced or eliminated within 96 h after treatment, demonstrating a high resilience in the natural bacterial community. Potential pathogens, including a Clostridium sp., inhabited the coral at low abundances, only becoming prevalent when the natural microbiota was disturbed by the treatment. The healthy coral-associated microbiota appears to be strongly controlled by microbial interactions.

  2. Evidence for Autoinduction and Quorum Sensing in White Band Disease-Causing Microbes on Acropora cervicornis

    NASA Astrophysics Data System (ADS)

    Certner, Rebecca H.; Vollmer, Steven V.

    2015-06-01

    Coral reefs have entered a state of global decline party due to an increasing incidence of coral disease. However, the diversity and complexity of coral-associated bacterial communities has made identifying the mechanisms underlying disease transmission and progression extremely difficult. This study explores the effects of coral cell-free culture fluid (CFCF) and autoinducer (a quorum sensing signaling molecule) on coral-associated bacterial growth and on coral tissue loss respectively. All experiments were conducted using the endangered Caribbean coral Acropora cervicornis. Coral-associated microbes were grown on selective media infused with CFCF derived from healthy and white band disease-infected A. cervicornis. Exposure to diseased CFCF increased proliferation of Cytophaga-Flavobacterium spp. while exposure to healthy CFCF inhibited growth of this group. Exposure to either CFCF did not significantly affect Vibrio spp. growth. In order to test whether disease symptoms can be induced in healthy corals, A. cervicornis was exposed to bacterial assemblages supplemented with exogenous, purified autoinducer. Incubation with autoinducer resulted in complete tissue loss in all corals tested in less than one week. These findings indicate that white band disease in A. cervicornis may be caused by opportunistic pathogenesis of resident microbes.

  3. Climate Change Impacts on the Tree of Life: Changes in Phylogenetic Diversity Illustrated for Acropora Corals

    PubMed Central

    Faith, Daniel P.; Richards, Zoe T.

    2012-01-01

    The possible loss of whole branches from the tree of life is a dramatic, but under-studied, biological implication of climate change. The tree of life represents an evolutionary heritage providing both present and future benefits to humanity, often in unanticipated ways. Losses in this evolutionary (evo) life-support system represent losses in “evosystem” services, and are quantified using the phylogenetic diversity (PD) measure. High species-level biodiversity losses may or may not correspond to high PD losses. If climate change impacts are clumped on the phylogeny, then loss of deeper phylogenetic branches can mean disproportionately large PD loss for a given degree of species loss. Over time, successive species extinctions within a clade each may imply only a moderate loss of PD, until the last species within that clade goes extinct, and PD drops precipitously. Emerging methods of “phylogenetic risk analysis” address such phylogenetic tipping points by adjusting conservation priorities to better reflect risk of such worst-case losses. We have further developed and explored this approach for one of the most threatened taxonomic groups, corals. Based on a phylogenetic tree for the corals genus Acropora, we identify cases where worst-case PD losses may be avoided by designing risk-averse conservation priorities. We also propose spatial heterogeneity measures changes to assess possible changes in the geographic distribution of corals PD. PMID:24832524

  4. Population Genetic Structure, Abundance, and Health Status of Two Dominant Benthic Species in the Saba Bank National Park, Caribbean Netherlands: Montastraea cavernosa and Xestospongia muta.

    PubMed

    de Bakker, Didier M; Meesters, Erik H W G; van Bleijswijk, Judith D L; Luttikhuizen, Pieternella C; Breeuwer, Hans J A J; Becking, Leontine E

    2016-01-01

    Saba Bank, a submerged atoll in the Caribbean Sea with an area of 2,200 km2, has attained international conservation status due to the rich diversity of species that reside on the bank. In order to assess the role of Saba Bank as a potential reservoir of diversity for the surrounding reefs, we examined the population genetic structure, abundance and health status of two prominent benthic species, the coral Montastraea cavernosa and the sponge Xestospongia muta. Sequence data were collected from 34 colonies of M. cavernosa (nDNA ITS1-5.8S-ITS2; 892 bp) and 68 X. muta sponges (mtDNA I3-M11 partition of COI; 544 bp) on Saba Bank and around Saba Island, and compared with published data across the wider Caribbean. Our data indicate that there is genetic connectivity between populations on Saba Bank and the nearby Saba Island as well as multiple locations in the wider Caribbean, ranging in distance from 100s-1000s km. The genetic diversity of Saba Bank populations of M. cavernosa (π = 0.055) and X. muta (π = 0.0010) was comparable to those in other regions in the western Atlantic. Densities and health status were determined along 11 transects of 50 m2 along the south-eastern rim of Saba Bank. The densities of M. cavernosa (0.27 ind. m-2, 95% CI: 0.12-0.52) were average, while the densities of X. muta (0.09 ind. m-2, 95% CI: 0.02-0.32) were generally higher with respect to other Caribbean locations. No disease or bleaching was present in any of the specimens of the coral M. cavernosa, however, we did observe partial tissue loss (77.9% of samples) as well as overgrowth (48.1%), predominantly by cyanobacteria. In contrast, the majority of observed X. muta (83.5%) showed signs of presumed bleaching. The combined results of apparent gene flow among populations on Saba Bank and surrounding reefs, the high abundance and unique genetic diversity, indicate that Saba Bank could function as an important buffer for the region. Either as a natural source of larvae to replenish

  5. Population Genetic Structure, Abundance, and Health Status of Two Dominant Benthic Species in the Saba Bank National Park, Caribbean Netherlands: Montastraea cavernosa and Xestospongia muta

    PubMed Central

    de Bakker, Didier M.; Meesters, Erik H. W. G.; van Bleijswijk, Judith D. L.; Luttikhuizen, Pieternella C.; Breeuwer, Hans J. A. J.; Becking, Leontine E.

    2016-01-01

    Saba Bank, a submerged atoll in the Caribbean Sea with an area of 2,200 km2, has attained international conservation status due to the rich diversity of species that reside on the bank. In order to assess the role of Saba Bank as a potential reservoir of diversity for the surrounding reefs, we examined the population genetic structure, abundance and health status of two prominent benthic species, the coral Montastraea cavernosa and the sponge Xestospongia muta. Sequence data were collected from 34 colonies of M. cavernosa (nDNA ITS1-5.8S-ITS2; 892 bp) and 68 X. muta sponges (mtDNA I3-M11 partition of COI; 544 bp) on Saba Bank and around Saba Island, and compared with published data across the wider Caribbean. Our data indicate that there is genetic connectivity between populations on Saba Bank and the nearby Saba Island as well as multiple locations in the wider Caribbean, ranging in distance from 100s–1000s km. The genetic diversity of Saba Bank populations of M. cavernosa (π = 0.055) and X. muta (π = 0.0010) was comparable to those in other regions in the western Atlantic. Densities and health status were determined along 11 transects of 50 m2 along the south-eastern rim of Saba Bank. The densities of M. cavernosa (0.27 ind. m-2, 95% CI: 0.12–0.52) were average, while the densities of X. muta (0.09 ind. m-2, 95% CI: 0.02–0.32) were generally higher with respect to other Caribbean locations. No disease or bleaching was present in any of the specimens of the coral M. cavernosa, however, we did observe partial tissue loss (77.9% of samples) as well as overgrowth (48.1%), predominantly by cyanobacteria. In contrast, the majority of observed X. muta (83.5%) showed signs of presumed bleaching. The combined results of apparent gene flow among populations on Saba Bank and surrounding reefs, the high abundance and unique genetic diversity, indicate that Saba Bank could function as an important buffer for the region. Either as a natural source of larvae to

  6. Population Genetic Structure, Abundance, and Health Status of Two Dominant Benthic Species in the Saba Bank National Park, Caribbean Netherlands: Montastraea cavernosa and Xestospongia muta.

    PubMed

    de Bakker, Didier M; Meesters, Erik H W G; van Bleijswijk, Judith D L; Luttikhuizen, Pieternella C; Breeuwer, Hans J A J; Becking, Leontine E

    2016-01-01

    Saba Bank, a submerged atoll in the Caribbean Sea with an area of 2,200 km2, has attained international conservation status due to the rich diversity of species that reside on the bank. In order to assess the role of Saba Bank as a potential reservoir of diversity for the surrounding reefs, we examined the population genetic structure, abundance and health status of two prominent benthic species, the coral Montastraea cavernosa and the sponge Xestospongia muta. Sequence data were collected from 34 colonies of M. cavernosa (nDNA ITS1-5.8S-ITS2; 892 bp) and 68 X. muta sponges (mtDNA I3-M11 partition of COI; 544 bp) on Saba Bank and around Saba Island, and compared with published data across the wider Caribbean. Our data indicate that there is genetic connectivity between populations on Saba Bank and the nearby Saba Island as well as multiple locations in the wider Caribbean, ranging in distance from 100s-1000s km. The genetic diversity of Saba Bank populations of M. cavernosa (π = 0.055) and X. muta (π = 0.0010) was comparable to those in other regions in the western Atlantic. Densities and health status were determined along 11 transects of 50 m2 along the south-eastern rim of Saba Bank. The densities of M. cavernosa (0.27 ind. m-2, 95% CI: 0.12-0.52) were average, while the densities of X. muta (0.09 ind. m-2, 95% CI: 0.02-0.32) were generally higher with respect to other Caribbean locations. No disease or bleaching was present in any of the specimens of the coral M. cavernosa, however, we did observe partial tissue loss (77.9% of samples) as well as overgrowth (48.1%), predominantly by cyanobacteria. In contrast, the majority of observed X. muta (83.5%) showed signs of presumed bleaching. The combined results of apparent gene flow among populations on Saba Bank and surrounding reefs, the high abundance and unique genetic diversity, indicate that Saba Bank could function as an important buffer for the region. Either as a natural source of larvae to replenish

  7. Evaluation of food grade solvents for lipid extraction and impact of storage temperature on fatty acid composition of edible seaweeds Laminaria digitata (Phaeophyceae) and Palmaria palmata (Rhodophyta).

    PubMed

    Schmid, Matthias; Guihéneuf, Freddy; Stengel, Dagmar B

    2016-10-01

    This study evaluated the impact of different food- and non-food grade extraction solvents on yield and fatty acid composition of the lipid extracts of two seaweed species (Palmaria palmata and Laminaria digitata). The application of chloroform/methanol and three different food grade solvents (ethanol, hexane, ethanol/hexane) revealed significant differences in both, extraction yield and fatty acid composition. The extraction efficiency, in terms of yields of total fatty acids (TFA), was in the order: chloroform/methanol>ethanol>hexane>ethanol/hexane for both species. Highest levels of polyunsaturated fatty acids (PUFA) were achieved by the extraction with ethanol. Additionally the effect of storage temperature on the stability of PUFA in ground and freeze-dried seaweed biomass was investigated. Seaweed samples were stored for a total duration of 22months at three different temperatures (-20°C, 4°C and 20°C). Levels of TFA and PUFA were only stable after storage at -20°C for the two seaweed species. PMID:27132836

  8. Polar lipids from the marine macroalga Palmaria palmata inhibit lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophage cells.

    PubMed

    Banskota, Arjun H; Stefanova, Roumiana; Sperker, Sandra; Lall, Santosh P; Craigie, James S; Hafting, Jeff T; Critchley, Alan T

    2014-05-01

    The EtOAc soluble fraction of a MeOH/CHCl3 extract of Palmaria palmata showed strong nitric oxide (NO) inhibitory activity against lipopolysaccharide (LPS)-induced NO production in murine RAW264.7 cells. NO inhibition-guided isolation led to identification of three new polar lipids including a sulfoquinovosyl diacylglycerol (SQDG) (2S)-1-O-eicosapentaenoyl-2-O-myristoyl-3-O-(6-sulfo-α-D-quinovopyranosyl)-glycerol (1) and two phosphatidylglycerols, 1-O-eicosapentaenoyl-2-O-trans-3-hexadecenoyl-3-phospho-(1'-glycerol)-glycerol (3) and 1-O-eicosapentaenoyl-2-O-palmitoyl-3-phospho-(1'-glycerol)-glycerol (4) from the EtOAc fraction. Seven known lipids were also isolated including a SQDG (2), a phospholipid (5) and five galactolipids (6-10). Structures of the isolated lipids were elucidated by spectral analyses. The isolated SQDGs, phosphatidylglycerols and phospholipid possessed strong and dose-dependent NO inhibitory activity compared to N(G)-methyl-L-arginine acetate salt (L-NMMA), a well-known NO inhibitor used as a positive control. Further study suggested that these polar lipids suppressed NO production through down-regulation of inducible nitric oxide synthase (iNOS). PMID:24569177

  9. Evaluation of food grade solvents for lipid extraction and impact of storage temperature on fatty acid composition of edible seaweeds Laminaria digitata (Phaeophyceae) and Palmaria palmata (Rhodophyta).

    PubMed

    Schmid, Matthias; Guihéneuf, Freddy; Stengel, Dagmar B

    2016-10-01

    This study evaluated the impact of different food- and non-food grade extraction solvents on yield and fatty acid composition of the lipid extracts of two seaweed species (Palmaria palmata and Laminaria digitata). The application of chloroform/methanol and three different food grade solvents (ethanol, hexane, ethanol/hexane) revealed significant differences in both, extraction yield and fatty acid composition. The extraction efficiency, in terms of yields of total fatty acids (TFA), was in the order: chloroform/methanol>ethanol>hexane>ethanol/hexane for both species. Highest levels of polyunsaturated fatty acids (PUFA) were achieved by the extraction with ethanol. Additionally the effect of storage temperature on the stability of PUFA in ground and freeze-dried seaweed biomass was investigated. Seaweed samples were stored for a total duration of 22months at three different temperatures (-20°C, 4°C and 20°C). Levels of TFA and PUFA were only stable after storage at -20°C for the two seaweed species.

  10. Expression of Putative Immune Response Genes during Early Ontogeny in the Coral Acropora millepora

    PubMed Central

    Puill-Stephan, Eneour; Seneca, François O.; Miller, David J.; van Oppen, Madeleine J. H.; Willis, Bette L.

    2012-01-01

    Background Corals, like many other marine invertebrates, lack a mature allorecognition system in early life history stages. Indeed, in early ontogeny, when corals acquire and establish associations with various surface microbiota and dinoflagellate endosymbionts, they do not efficiently distinguish between closely and distantly related individuals from the same population. However, very little is known about the molecular components that underpin allorecognition and immunity responses or how they change through early ontogeny in corals. Methodology/Principal Findings Patterns in the expression of four putative immune response genes (apextrin, complement C3, and two CELIII type lectin genes) were examined in juvenile colonies of Acropora millepora throughout a six-month post-settlement period using quantitative real-time PCR (qPCR). Expression of a CELIII type lectin gene peaked in the fourth month for most of the coral juveniles sampled and was significantly higher at this time than at any other sampling time during the six months following settlement. The timing of this increase in expression levels of putative immune response genes may be linked to allorecognition maturation which occurs around this time in A.millepora. Alternatively, the increase may represent a response to immune challenges, such as would be involved in the recognition of symbionts (such as Symbiodinium spp. or bacteria) during winnowing processes as symbioses are fine-tuned. Conclusions/Significance Our data, although preliminary, are consistent with the hypothesis that lectins may play an important role in the maturation of allorecognition responses in corals. The co-expression of lectins with apextrin during development of coral juveniles also raises the possibility that these proteins, which are components of innate immunity in other invertebrates, may influence the innate immune systems of corals through a common pathway or system. However, further studies investigating the expression of

  11. Is Echinometra viridis facilitating a phase shift on an Acropora cervicornis patch reef in Belize?

    NASA Astrophysics Data System (ADS)

    Stefanic, C. M.; Greer, L.; Norvell, D.; Benson, W.; Curran, H.

    2012-12-01

    Coral reef health is in rapid decline across the Caribbean due to a number of anthropogenic and natural disturbances. A phase shift from coral- to macroalgae-dominant reefs is pervasive and has been well documented. Acropora cervicornis (Staghorn Coral) has been particularly affected by this shift due to mass mortality of this species since the 1980s. In recent years few Caribbean A. cervicornis refugia have been documented. This study characterizes the relationship between coral and grazing urchins on a rare patch reef system dominated by A. cervicornis off the coast of Belize. To assess relative abundance of live A. cervicornis and the urchin Echinometra viridis, photographs and urchin abundance data were collected from 132 meter square quadrats along five transects across the reef. Photographs were digitized and manually segmented using Adobe Illustrator, and percent live coral cover and branch tip densities were calculated using Matlab. Mean percent live coral cover across all transects was 24.4 % with a high of 65% live coral per meter square. Average urchin density was 18.5 per quadrat, with an average density per transect ranging from 22.1 to 0.5 per quadrat. Up to over 400 live A. cervicornis branch tips per quadrat were observed. Data show a positive correlation between E. viridis abundance and live A. cervicornis, suggesting that these urchins are facilitating recovery or persistence of this endangered coral species. These results suggest the relationship between E. viridis and A. cervicornis could be a key element in a future reversal of the coral to macroalgae phase shift on some Caribbean coral reefs.

  12. Gene expression patterns of the coral Acropora millepora in response to contact with macroalgae

    PubMed Central

    Shearer, TL; Rasher, DB; Snell, TW; Hay, ME

    2013-01-01

    Contact with macroalgae often causes coral mortality, but the roles of abrasion versus shading versus allelopathy in these interactions are rarely clear and effects on gene expression are unknown. Identification of gene expression changes within corals in response to contact with macroalgae can provide insight into the mode of action of allelochemicals, as well as reveal transcriptional strategies of the coral that mitigate damage from this competitive interaction, enabling the coral to survive. Gene expression responses of the coral Acropora millepora after long-term (20 d) direct contact with macroalgae (Chlorodesmis fastigiata, Dictyota bartayresiana, Galaxaura filamentosa and Turbinaria conoides) and short-term (1 h and 24 h) exposure to C. fastigiata thalli and their hydrophobic extract were assessed. After 20 d of exposure, T. conoides thalli elicited no significant change in visual bleaching or zooxanthellae PSII quantum yield within A. millepora nubbins, but stimulated the greatest alteration in gene expression of all treatments. Chlorodesmis fastigiata, D. bartayresiana and G. filamentosa caused significant visual bleaching of coral nubbins and reduced the PSII quantum yield of associated zooxanthellae after 20 d, but elicited fewer changes in gene expression relative to T. conoides at day 20. To evaluate initial molecular processes leading to reduction of zooxanthella PSII quantum yield, visual bleaching, and coral death, short-term exposures to C. fastigiata thalli and hydrophobic extracts were conducted; these interactions revealed protein degradation and significant changes in catalytic and metabolic activity within 24 h of contact. These molecular responses are consistent with the hypothesis that allelopathic interactions lead to alteration of signal transduction and an imbalance between reactive oxidant species production and antioxidant capabilities within the coral holobiont. This oxidative imbalance results in rapid protein degradation and

  13. The combined effects of temperature and CO2 lead to altered gene expression in Acropora aspera

    NASA Astrophysics Data System (ADS)

    Ogawa, D.; Bobeszko, T.; Ainsworth, T.; Leggat, W.

    2013-12-01

    This study explored the interactive effects of near-term CO2 increases (40-90 ppm above current ambient) during a simulated bleaching event (34 °C for 5 d) of Acropora aspera by linking physiology to expression patterns of genes involved in carbon metabolism. Symbiodinium photosynthetic efficiency ( F v / F m ) was significantly depressed by the bleaching event, while elevated pressure of CO2 (pCO2) slightly mitigated the effects of increased temperature on F v / F m during the final 4 d of the recovery period, however, did not affect the loss of symbionts. Elevated pCO2 alone had no effect on F v / F m or symbiont density. Expression of targeted Symbiodinium genes involved in carbon metabolism and heat stress response was not significantly altered by either increased temperature and/or CO2. Of the selected host genes, two carbonic anhydrase isoforms (coCA2 and coCA3) exhibited the largest changes, most notably in crossed bleaching and elevated pCO2 treatments. CA2 was significantly down-regulated on day 14 in all treatments, with the greatest decrease in the crossed treatment (relative expression compared to control = 0.16; p < 0.05); CA3 showed a similar trend, with expression levels 0.20-fold of controls on day 14 ( p < 0.05) in the elevated temperature/pCO2 treatment. The synergistic effects of ocean acidification and bleaching were evident during this study and demonstrate that increased pCO2 in surface waters will impact corals much sooner than many studies utilising end-of-century pCO2 concentrations would indicate.

  14. Mucus Sugar Content Shapes the Bacterial Community Structure in Thermally Stressed Acropora muricata.

    PubMed

    Lee, Sonny T M; Davy, Simon K; Tang, Sen-Lin; Kench, Paul S

    2016-01-01

    It has been proposed that the chemical composition of a coral's mucus can influence the associated bacterial community. However, information on this topic is rare, and non-existent for corals that are under thermal stress. This study therefore compared the carbohydrate composition of mucus in the coral Acropora muricata when subjected to increasing thermal stress from 26 to 31°C, and determined whether this composition correlated with any changes in the bacterial community. Results showed that, at lower temperatures, the main components of mucus were N-acetyl glucosamine and C6 sugars, but these constituted a significantly lower proportion of the mucus in thermally stressed corals. The change in the mucus composition coincided with a shift from a γ-Proteobacteria- to a Verrucomicrobiae- and α-Proteobacteria-dominated community in the coral mucus. Bacteria in the class Cyanobacteria also started to become prominent in the mucus when the coral was thermally stressed. The increase in the relative abundance of the Verrucomicrobiae at higher temperature was strongly associated with a change in the proportion of fucose, glucose, and mannose in the mucus. Increase in the relative abundance of α-Proteobacteria were associated with GalNAc and glucose, while the drop in relative abundance of γ-Proteobacteria at high temperature coincided with changes in fucose and mannose. Cyanobacteria were highly associated with arabinose and xylose. Changes in mucus composition and the bacterial community in the mucus layer occurred at 29°C, which were prior to visual signs of coral bleaching at 31°C. A compositional change in the coral mucus, induced by thermal stress could therefore be a key factor leading to a shift in the associated bacterial community. This, in turn, has the potential to impact the physiological function of the coral holobiont. PMID:27047481

  15. Toxic coral gobies reduce the feeding rate of a corallivorous butterflyfish on Acropora corals

    NASA Astrophysics Data System (ADS)

    Dirnwoeber, M.; Herler, J.

    2013-03-01

    The obligate coral-dwelling gobiid genus Gobiodon inhabits Acropora corals and has developed various physiological, morphological and ethological adaptations towards this life habit. While the advantages of this coral-fish association are well documented for Gobiodon, possible fitness-increasing factors for the host coral are unknown. This study examines the influence of coral-dwelling gobies on the feeding behaviour of obligate corallivorous butterflyfishes. In an aquarium experiment using video observation, the corallivorous butterflyfish Chaetodon austriacus fed significantly less on corals inhabited by two Gobiodon species compared to unoccupied coral colonies of similar size. The more agonistic species G. histrio, which mostly displayed directed movements towards butterflyfishes, decreased butterflyfish bite rate by 62-98 % compared to uninhabited colonies. For Gobiodon sp. 3, which mostly displayed undirected movements in response to visits by C. austriacus, bite rate reduction was 64-68 %. The scale-less skin of Gobiodon spp. is covered by mucus that is toxic and multi-functional by reducing predation as well as affecting parasite attachment. A choice flume experiment suggests that the highly diluted skin mucus of Gobiodon spp. also functions as a corallivore repellent. This study demonstrates that Gobiodon spp. exhibit resource defence against coral-feeding butterflyfishes and also that coral colonies without resident Gobiodon suffer higher predation rates. Although the genus Gobiodon is probably a facultative corallivore, this study shows that by reducing predation on inhabited colonies by other fishes, these obligate coral-dwellers either compensate for their own fitness-decreasing impact on host colonies or live in a mutualistic association with them.

  16. Disease dynamics and potential mitigation among restored and wild staghorn coral, Acropora cervicornis

    PubMed Central

    Lohr, Kathryn E.; Cameron, Caitlin M.; Williams, Dana E.; Peters, Esther C.

    2014-01-01

    The threatened status (both ecologically and legally) of Caribbean staghorn coral, Acropora cervicornis, has prompted rapidly expanding efforts in culture and restocking, although tissue loss diseases continue to affect populations. In this study, disease surveillance and histopathological characterization were used to compare disease dynamics and conditions in both restored and extant wild populations. Disease had devastating effects on both wild and restored populations, but dynamics were highly variable and appeared to be site-specific with no significant differences in disease prevalence between wild versus restored sites. A subset of 20 haphazardly selected colonies at each site observed over a four-month period revealed widely varying disease incidence, although not between restored and wild sites, and a case fatality rate of 8%. A tropical storm was the only discernable environmental trigger associated with a consistent spike in incidence across all sites. Lastly, two field mitigation techniques, (1) excision of apparently healthy branch tips from a diseased colony, and (2) placement of a band of epoxy fully enclosing the diseased margin, gave equivocal results with no significant benefit detected for either treatment compared to controls. Tissue condition of associated samples was fair to very poor; unsuccessful mitigation treatment samples had severe degeneration of mesenterial filament cnidoglandular bands. Polyp mucocytes in all samples were infected with suspect rickettsia-like organisms; however, no bacterial aggregates were found. No histological differences were found between disease lesions with gross signs fitting literature descriptions of white-band disease (WBD) and rapid tissue loss (RTL). Overall, our results do not support differing disease quality, quantity, dynamics, nor health management strategies between restored and wild colonies of A. cervicornis in the Florida Keys. PMID:25210660

  17. Mucus Sugar Content Shapes the Bacterial Community Structure in Thermally Stressed Acropora muricata

    PubMed Central

    Lee, Sonny T. M.; Davy, Simon K.; Tang, Sen-Lin; Kench, Paul S.

    2016-01-01

    It has been proposed that the chemical composition of a coral’s mucus can influence the associated bacterial community. However, information on this topic is rare, and non-existent for corals that are under thermal stress. This study therefore compared the carbohydrate composition of mucus in the coral Acropora muricata when subjected to increasing thermal stress from 26 to 31°C, and determined whether this composition correlated with any changes in the bacterial community. Results showed that, at lower temperatures, the main components of mucus were N-acetyl glucosamine and C6 sugars, but these constituted a significantly lower proportion of the mucus in thermally stressed corals. The change in the mucus composition coincided with a shift from a γ-Proteobacteria- to a Verrucomicrobiae- and α-Proteobacteria-dominated community in the coral mucus. Bacteria in the class Cyanobacteria also started to become prominent in the mucus when the coral was thermally stressed. The increase in the relative abundance of the Verrucomicrobiae at higher temperature was strongly associated with a change in the proportion of fucose, glucose, and mannose in the mucus. Increase in the relative abundance of α-Proteobacteria were associated with GalNAc and glucose, while the drop in relative abundance of γ-Proteobacteria at high temperature coincided with changes in fucose and mannose. Cyanobacteria were highly associated with arabinose and xylose. Changes in mucus composition and the bacterial community in the mucus layer occurred at 29°C, which were prior to visual signs of coral bleaching at 31°C. A compositional change in the coral mucus, induced by thermal stress could therefore be a key factor leading to a shift in the associated bacterial community. This, in turn, has the potential to impact the physiological function of the coral holobiont. PMID:27047481

  18. Possible return of Acropora cervicornis at Pulaski Shoal, Dry Tortugas National Park, Florida

    USGS Publications Warehouse

    Lidz, Barbara H.; Zawada, David G.

    2013-01-01

    Seabed classification is essential to assessing environmental associations and physical status in coral reef ecosystems. At Pulaski Shoal in Dry Tortugas National Park, Florida, nearly continuous underwater-image coverage was acquired in 15.5 hours in 2009 along 70.2 km of transect lines spanning ~0.2 km2. The Along-Track Reef-Imaging System (ATRIS), a boat-based, high-speed, digital imaging system, was used. ATRIS-derived benthic classes were merged with a QuickBird satellite image to create a habitat map that defines areas of senile coral reef, carbonate sand, seagrasses, and coral rubble. This atypical approach of starting with extensive, high-resolution in situ imagery and extrapolating between transect lines using satellite imagery leverages the strengths of each remote-sensing modality. The ATRIS images also captured the spatial distribution of two species once common on now-degraded Florida-Caribbean coral reefs: the stony staghorn coral Acropora cervicornis, a designated threatened species, and the long-spined urchin Diadema antillarum. This article documents the utility of ATRIS imagery for quantifying number and estimating age of A. cervicornis colonies (n = 400, age range, 5–11 y) since the severe hypothermic die-off in the Dry Tortugas in 1976–77. This study is also the first to document the largest number of new colonies of A. cervicornis tabulated in an area of the park where coral-monitoring stations maintained by the Fish and Wildlife Research Institute have not been established. The elevated numbers provide an updated baseline for tracking revival of this species at Pulaski Shoal.

  19. Toxic coral gobies reduce the feeding rate of a corallivorous butterflyfish on Acropora corals.

    PubMed

    Dirnwoeber, M; Herler, J

    2013-03-01

    The obligate coral-dwelling gobiid genus Gobiodon inhabits Acropora corals and has developed various physiological, morphological and ethological adaptations towards this life habit. While the advantages of this coral-fish association are well documented for Gobiodon, possible fitness-increasing factors for the host coral are unknown. This study examines the influence of coral-dwelling gobies on the feeding behaviour of obligate corallivorous butterflyfishes. In an aquarium experiment using video observation, the corallivorous butterflyfish Chaetodon austriacus fed significantly less on corals inhabited by two Gobiodon species compared to unoccupied coral colonies of similar size. The more agonistic species G. histrio, which mostly displayed directed movements towards butterflyfishes, decreased butterflyfish bite rate by 62-98 % compared to uninhabited colonies. For Gobiodon sp. 3, which mostly displayed undirected movements in response to visits by C. austriacus, bite rate reduction was 64-68 %. The scale-less skin of Gobiodon spp. is covered by mucus that is toxic and multi-functional by reducing predation as well as affecting parasite attachment. A choice flume experiment suggests that the highly diluted skin mucus of Gobiodon spp. also functions as a corallivore repellent. This study demonstrates that Gobiodon spp. exhibit resource defence against coral-feeding butterflyfishes and also that coral colonies without resident Gobiodon suffer higher predation rates. Although the genus Gobiodon is probably a facultative corallivore, this study shows that by reducing predation on inhabited colonies by other fishes, these obligate coral-dwellers either compensate for their own fitness-decreasing impact on host colonies or live in a mutualistic association with them. PMID:24443641

  20. Gene expression patterns of the coral Acropora millepora in response to contact with macroalgae

    NASA Astrophysics Data System (ADS)

    Shearer, T. L.; Rasher, D. B.; Snell, T. W.; Hay, M. E.

    2012-12-01

    Contact with macroalgae often causes coral mortality, but the roles of abrasion versus shading versus allelopathy in these interactions are rarely clear, and effects on gene expression are unknown. Identification of gene expression changes within corals in response to contact with macroalgae can provide insight into the mode of action of allelochemicals, as well as reveal transcriptional strategies of the coral that mitigate damage from this competitive interaction, enabling the coral to survive. Gene expression responses of the coral Acropora millepora after long-term (20 days) direct contact with macroalgae ( Chlorodesmis fastigiata, Dictyota bartayresiana, Galaxaura filamentosa, and Turbinaria conoides) and short-term (1 and 24 h) exposure to C. fastigiata thalli and their hydrophobic extract were assessed. After 20 days of exposure, T. conoides thalli elicited no significant change in visual bleaching or zooxanthellae PSII quantum yield within A. millepora nubbins, but stimulated the greatest alteration in gene expression of all treatments. Chlorodesmis fastigiata, D. bartayresiana, and G. filamentosa caused significant visual bleaching of coral nubbins and reduced the PSII quantum yield of associated zooxanthellae after 20 days, but elicited fewer changes in gene expression relative to T. conoides at day 20. To evaluate initial molecular processes leading to reduction of zooxanthella PSII quantum yield, visual bleaching, and coral death, short-term exposures to C. fastigiata thalli and hydrophobic extracts were conducted; these interactions revealed protein degradation and significant changes in catalytic and metabolic activity within 24 h of contact. These molecular responses are consistent with the hypothesis that allelopathic interactions lead to alteration of signal transduction and an imbalance between reactive oxidant species production and antioxidant capabilities within the coral holobiont. This oxidative imbalance results in rapid protein degradation

  1. Gene expression patterns of the coral Acropora millepora in response to contact with macroalgae.

    PubMed

    Shearer, Tl; Rasher, Db; Snell, Tw; Hay, Me

    2012-12-01

    Contact with macroalgae often causes coral mortality, but the roles of abrasion versus shading versus allelopathy in these interactions are rarely clear and effects on gene expression are unknown. Identification of gene expression changes within corals in response to contact with macroalgae can provide insight into the mode of action of allelochemicals, as well as reveal transcriptional strategies of the coral that mitigate damage from this competitive interaction, enabling the coral to survive. Gene expression responses of the coral Acropora millepora after long-term (20 d) direct contact with macroalgae (Chlorodesmis fastigiata, Dictyota bartayresiana, Galaxaura filamentosa and Turbinaria conoides) and short-term (1 h and 24 h) exposure to C. fastigiata thalli and their hydrophobic extract were assessed. After 20 d of exposure, T. conoides thalli elicited no significant change in visual bleaching or zooxanthellae PSII quantum yield within A. millepora nubbins, but stimulated the greatest alteration in gene expression of all treatments. Chlorodesmis fastigiata, D. bartayresiana and G. filamentosa caused significant visual bleaching of coral nubbins and reduced the PSII quantum yield of associated zooxanthellae after 20 d, but elicited fewer changes in gene expression relative to T. conoides at day 20. To evaluate initial molecular processes leading to reduction of zooxanthella PSII quantum yield, visual bleaching, and coral death, short-term exposures to C. fastigiata thalli and hydrophobic extracts were conducted; these interactions revealed protein degradation and significant changes in catalytic and metabolic activity within 24 h of contact. These molecular responses are consistent with the hypothesis that allelopathic interactions lead to alteration of signal transduction and an imbalance between reactive oxidant species production and antioxidant capabilities within the coral holobiont. This oxidative imbalance results in rapid protein degradation and

  2. Demography of the threatened coral Acropora cervicornis: implications for its management and conservation

    NASA Astrophysics Data System (ADS)

    Mercado-Molina, Alex E.; Ruiz-Diaz, Claudia P.; Pérez, María E.; Rodríguez-Barreras, Ruber; Sabat, Alberto M.

    2015-12-01

    Populations of Acropora cervicornis have collapsed throughout the Caribbean. This situation has prompted the initiation of many restoration efforts; yet, there are insufficient demographic data and analyses to effectively guide these initiatives. In this study we assessed the spatiotemporal variability of A. cervicornis vital rates. We also developed a population matrix model to (1) evaluate the risk of population extinction, (2) estimate population growth rates (λ) considering different rates of colony fragmentation and fragment survival, (3) determine the demographic transition(s) that contribute the most to spatiotemporal differences in λs, and (4) analyze the effectiveness of outplanting coral fragments of different sizes. The model was parameterized by following the fate of 300 colonies from 2011 to 2013 at two localities in Puerto Rico. Demographic transitions varied spatiotemporally, with a significant interaction between location and time period on colony fate. Spatiotemporal variations in λ were also observed. During the first year, populations exhibited λs below equilibrium (0.918 and 0.948), followed by a dramatic decline at both sites (0.535 and 0.709) during the second year. The lower λs were caused by a decrease in the probability of stasis of large-sized colonies coupled with lack of sexual recruits and a meager contribution of asexual recruitment. Spatial variations in λs were largely due to differences in the probability of medium-sized colonies advancing to the largest size class. The viability analysis forecasts that the populations will reach quasi-extinction levels of 25 % of the initial population size in ≤16 yrs. Numerical simulations indicate that outplanting fragments ≥250 cm in total linear length (TLL) would result in a higher asymptotic population size than outplanting smaller fragments. We argue, however, that transplanting colonies ≤100 cm TLL will be a better management strategy because they can be produced faster and in

  3. Lunar Phase Modulates Circadian Gene Expression Cycles in the Broadcast Spawning Coral Acropora millepora.

    PubMed

    Brady, Aisling K; Willis, Bette L; Harder, Lawrence D; Vize, Peter D

    2016-04-01

    Many broadcast spawning corals in multiple reef regions release their gametes with incredible temporal precision just once per year, using the lunar cycle to set the night of spawning. Moonlight, rather than tides or other lunar-regulated processes, is thought to be the proximate factor responsible for linking the night of spawning to the phase of the Moon. We compared patterns of gene expression among colonies of the broadcast spawning coral Acropora millepora at different phases of the lunar cycle, and when they were maintained under one of three experimentally simulated lunar lighting treatments: i) lunar lighting conditions matching those on the reef, or lunar patterns mimicking either ii) constant full Moon conditions, or iii) constant new Moon conditions. Normal lunar illumination was found to shift both the level and timing of clock gene transcription cycles between new and full moons, with the peak hour of expression for a number of genes occurring earlier in the evening under a new Moon when compared to a full Moon. When the normal lunar cycle is replaced with nighttime patterns equivalent to either a full Moon or a new Moon every evening, the normal monthlong changes in the level of expression are destroyed for most genes. In combination, these results indicate that daily changes in moonlight that occur over the lunar cycle are essential for maintaining normal lunar periodicity of clock gene transcription, and this may play a role in regulating spawn timing. These data also show that low levels of light pollution may have an impact on coral biological clocks. PMID:27132135

  4. The northern limit of corals of the genus Acropora in temperate zones is determined by their resilience to cold bleaching.

    PubMed

    Higuchi, Tomihiko; Agostini, Sylvain; Casareto, Beatriz Estela; Suzuki, Yoshimi; Yuyama, Ikuko

    2015-12-18

    The distribution of corals in Japan covers a wide range of latitudes, encompassing tropical to temperate zones. However, coral communities in temperate zones contain only a small subset of species. Among the parameters that determine the distribution of corals, temperature plays an important role. We tested the resilience to cold stress of three coral species belonging to the genus Acropora in incubation experiments. Acropora pruinosa, which is the northernmost of the three species, bleached at 13 °C, but recovered once temperatures were increased. The two other species, A. hyacinthus and A. solitaryensis, which has a more southerly range than A. pruinosa, died rapidly after bleaching at 13 °C. The physiological effects of cold bleaching on the corals included decreased rates of photosynthesis, respiration, and calcification, similar to the physiological effects observed with bleaching due to high temperature stress. Contrasting hot bleaching, no increases in antioxidant enzyme activities were observed, suggesting that reactive oxygen species play a less important role in bleaching under cold stress. These results confirmed the importance of resilience to cold stress in determining the distribution and northern limits of coral species, as cold events causing coral bleaching and high mortality occur regularly in temperate zones.

  5. The northern limit of corals of the genus Acropora in temperate zones is determined by their resilience to cold bleaching.

    PubMed

    Higuchi, Tomihiko; Agostini, Sylvain; Casareto, Beatriz Estela; Suzuki, Yoshimi; Yuyama, Ikuko

    2015-01-01

    The distribution of corals in Japan covers a wide range of latitudes, encompassing tropical to temperate zones. However, coral communities in temperate zones contain only a small subset of species. Among the parameters that determine the distribution of corals, temperature plays an important role. We tested the resilience to cold stress of three coral species belonging to the genus Acropora in incubation experiments. Acropora pruinosa, which is the northernmost of the three species, bleached at 13 °C, but recovered once temperatures were increased. The two other species, A. hyacinthus and A. solitaryensis, which has a more southerly range than A. pruinosa, died rapidly after bleaching at 13 °C. The physiological effects of cold bleaching on the corals included decreased rates of photosynthesis, respiration, and calcification, similar to the physiological effects observed with bleaching due to high temperature stress. Contrasting hot bleaching, no increases in antioxidant enzyme activities were observed, suggesting that reactive oxygen species play a less important role in bleaching under cold stress. These results confirmed the importance of resilience to cold stress in determining the distribution and northern limits of coral species, as cold events causing coral bleaching and high mortality occur regularly in temperate zones. PMID:26680690

  6. Colony geometry and structural complexity of the endangered species Acropora cervicornis partly explains the structure of their associated fish assemblage.

    PubMed

    Agudo-Adriani, Esteban A; Cappelletto, Jose; Cavada-Blanco, Francoise; Croquer, Aldo

    2016-01-01

    In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height), structural complexity (i.e., volume, density of branches, etc.) and biological features of the colonies (i.e., live coral tissue, algae). We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts. PMID:27069801

  7. The Neuronal Calcium Sensor Protein Acrocalcin: A Potential Target of Calmodulin Regulation during Development in the Coral Acropora millepora

    PubMed Central

    Reyes-Bermudez, Alejandro; Miller, David J.; Sprungala, Susanne

    2012-01-01

    To understand the calcium-mediated signalling pathways underlying settlement and metamorphosis in the Scleractinian coral Acropora millepora, a predicted protein set derived from larval cDNAs was scanned for the presence of EF-hand domains (Pfam Id: PF00036). This approach led to the identification of a canonical calmodulin (AmCaM) protein and an uncharacterised member of the Neuronal Calcium Sensor (NCS) family of proteins known here as Acrocalcin (AmAC). While AmCaM transcripts were present throughout development, AmAC transcripts were not detected prior to gastrulation, after which relatively constant mRNA levels were detected until metamorphosis and settlement. The AmAC protein contains an internal CaM-binding site and was shown to interact in vitro with AmCaM. These results are consistent with the idea that AmAC is a target of AmCaM in vivo, suggesting that this interaction may regulate calcium-dependent processes during the development of Acropora millepora. PMID:23284743

  8. Colony geometry and structural complexity of the endangered species Acropora cervicornis partly explains the structure of their associated fish assemblage.

    PubMed

    Agudo-Adriani, Esteban A; Cappelletto, Jose; Cavada-Blanco, Francoise; Croquer, Aldo

    2016-01-01

    In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height), structural complexity (i.e., volume, density of branches, etc.) and biological features of the colonies (i.e., live coral tissue, algae). We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts.

  9. The northern limit of corals of the genus Acropora in temperate zones is determined by their resilience to cold bleaching

    PubMed Central

    Higuchi, Tomihiko; Agostini, Sylvain; Casareto, Beatriz Estela; Suzuki, Yoshimi; Yuyama, Ikuko

    2015-01-01

    The distribution of corals in Japan covers a wide range of latitudes, encompassing tropical to temperate zones. However, coral communities in temperate zones contain only a small subset of species. Among the parameters that determine the distribution of corals, temperature plays an important role. We tested the resilience to cold stress of three coral species belonging to the genus Acropora in incubation experiments. Acropora pruinosa, which is the northernmost of the three species, bleached at 13 °C, but recovered once temperatures were increased. The two other species, A. hyacinthus and A. solitaryensis, which has a more southerly range than A. pruinosa, died rapidly after bleaching at 13 °C. The physiological effects of cold bleaching on the corals included decreased rates of photosynthesis, respiration, and calcification, similar to the physiological effects observed with bleaching due to high temperature stress. Contrasting hot bleaching, no increases in antioxidant enzyme activities were observed, suggesting that reactive oxygen species play a less important role in bleaching under cold stress. These results confirmed the importance of resilience to cold stress in determining the distribution and northern limits of coral species, as cold events causing coral bleaching and high mortality occur regularly in temperate zones. PMID:26680690

  10. Colony geometry and structural complexity of the endangered species Acropora cervicornis partly explains the structure of their associated fish assemblage

    PubMed Central

    Cappelletto, Jose; Cavada-Blanco, Francoise; Croquer, Aldo

    2016-01-01

    In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height), structural complexity (i.e., volume, density of branches, etc.) and biological features of the colonies (i.e., live coral tissue, algae). We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts. PMID:27069801

  11. Effect of ocean warming and acidification on the early life stages of subtropical Acropora spicifera

    NASA Astrophysics Data System (ADS)

    Foster, T.; Gilmour, J. P.; Chua, C. M.; Falter, J. L.; McCulloch, M. T.

    2015-12-01

    This study investigated the impacts of acidified seawater ( pCO2 ~ 900 μatm) and elevated water temperature (+3 °C) on the early life history stages of Acropora spicifera from the subtropical Houtman Abrolhos Islands (28°S) in Western Australia. Settlement rates were unaffected by high temperature (27 °C, ~250 μatm), high pCO2 (24 °C, ~900 μatm), or a combination of both high temperature and high pCO2 treatments (27 °C, ~900 μatm). There were also no significant differences in rates of post-settlement survival after 4 weeks of exposure between any of the treatments, with survival ranging from 60 to 70 % regardless of treatment. Similarly, calcification, as determined by the skeletal weight of recruits, was unaffected by an increase in water temperature under both ambient and high pCO2 conditions. In contrast, high pCO2 significantly reduced early skeletal development, with mean skeletal weight in the high pCO2 and combined treatments reduced by 60 and 48 %, respectively, compared to control weights. Elevated temperature appeared to have a partially mitigative effect on calcification under high pCO2; however, this effect was not significant. Our results show that rates of settlement, post-settlement survival, and calcification in subtropical corals are relatively resilient to increases in temperature. This is in marked contrast to the sensitivity to temperature reported for the majority of tropical larvae and recruits in the literature. The subtropical corals in this study appear able to withstand an increase in temperature of 3 °C above ambient, indicating that they may have a wider thermal tolerance range and may not be adversely affected by initial increases in water temperature from subtropical 24 to 27 °C. However, the reduction in skeletal weight with high pCO2 indicates that early skeletal formation will be highly vulnerable to the changes in ocean pCO2 expected to occur over the twenty-first century, with implications for their longer-term growth

  12. The complex NOD-like receptor repertoire of the coral Acropora digitifera includes novel domain combinations.

    PubMed

    Hamada, Mayuko; Shoguchi, Eiichi; Shinzato, Chuya; Kawashima, Takeshi; Miller, David J; Satoh, Nori

    2013-01-01

    Innate immunity in corals is of special interest not only in the context of self-defense but also in relation to the establishment and collapse of their obligate symbiosis with dinoflagellates of the genus Symbiodinium. In innate immunity system of vertebrates, approximately 20 tripartite nucleotide oligomerization domain (NOD)-like receptor proteins that are defined by the presence of a NAIP, CIIA, HET-E and TP1 (NACHT) domain, a C-terminal leucine-rich repeat (LRR) domain, and one of three types of N-terminal effector domain, are known to function as the primary intracellular pattern recognition molecules. Surveying the coral genome revealed not only a larger number of NACHT- and related domain nucleotide-binding adaptor shared by APAF-1, R proteins, and CED-4 (NB-ARC)-encoding loci (~500) than in other metazoans but also surprising diversity of domain combinations among the coral NACHT/NB-ARC-containing proteins; N-terminal effector domains included the apoptosis-related domains caspase recruitment domain (CARD), death effector domain (DED), and Death, and C-terminal repeat domains included LRRs, tetratricopeptide repeats, ankyrin repeats, and WD40 repeats. Many of the predicted coral proteins that contain a NACHT/NB-ARC domain also contain a glycosyl transferase group 1 domain, a novel domain combination first found in metazoans. Phylogenetic analyses suggest that the NACHT/NB-ARC domain inventories of various metazoan lineages, including corals, are largely products of lineage-specific expansions. Many of the NACHT/NB-ARC loci are organized in pairs or triplets in the Acropora genome, suggesting that the large coral NACHT/NB-ARC repertoire has been generated at least in part by tandem duplication. In addition, shuffling of N-terminal effector domains may have occurred after expansions of specific NACHT/NB-ARC-repeat domain types. These results illustrate the extraordinary complexity of the innate immune repertoire of corals, which may in part reflect adaptive

  13. Density of Diadema antillarum (Echinodermata: Echinoidea) on live coral patch reefs and dead Acropora cervicornis rubble patches near Loggerhead Key, Dry Tortugas National Park, Florida, USA

    EPA Science Inventory

    Density of adult Diadema antillarum was assessed on live coral patch reefs and dead Acropora cervicornis rubble patches next to Loggerhead Key, Dry Tortugas National Park, Florida, USA in June 2009. Mean density on live coral patch reefs (0.49 individuals m-2) was not statistical...

  14. Potential of a renin inhibitory peptide from the red seaweed Palmaria palmata as a functional food ingredient following confirmation and characterization of a hypotensive effect in spontaneously hypertensive rats.

    PubMed

    Fitzgerald, Ciaran; Aluko, Rotimi E; Hossain, Mohammad; Rai, Dilip K; Hayes, Maria

    2014-08-20

    This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived previously from a Palmaria palmata papain hydrolysate, during gastrointestinal (GI) transit. Following simulated GI digestion, breakdown products were identified using mass spectrometry analysis and the known renin and angiotensin I converting enzyme inhibitory dipeptide IR was identified. In vivo animal studies using spontaneously hypertensive rats (SHRs) were used to confirm the antihypertensive effects of both the tridecapeptide IRLIIVLMPILMA and the seaweed protein hydrolysate from which this peptide was isolated. After 24 h, the SHR group fed the P. palmata protein hydrolysate recorded a drop of 34 mm Hg in systolic blood pressure (SBP) from 187 (±0.25) to 153 (± 0.64) mm Hg SBP, while the group fed the tridecapeptide IRLIIVLMPLIMA presented a drop of 33 mm Hg in blood pressure from 187 (±0.95) to 154 (±0.94) mm Hg SBP compared to the SBP recorded at time zero. The results of this study indicate that the seaweed protein derived hydrolysate has potential for use as antihypertensive agents and that the tridecapeptide is cleaved and activated to the dipeptide IR when it travels through the GI tract. Both the hydrolysate and peptide reduced SHR blood pressure when administered orally over a 24 h period.

  15. Differential expression of three galaxin-related genes during settlement and metamorphosis in the scleractinian coral Acropora millepora

    PubMed Central

    Reyes-Bermudez, Alejandro; Lin, Zhiyi; Hayward, David C; Miller, David J; Ball, Eldon E

    2009-01-01

    Background The coral skeleton consists of CaCO3 deposited upon an organic matrix primarily as aragonite. Currently galaxin, from Galaxea fascicularis, is the only soluble protein component of the organic matrix that has been characterized from a coral. Three genes related to galaxin were identified in the coral Acropora millepora. Results One of the Acropora genes (Amgalaxin) encodes a clear galaxin ortholog, while the others (Amgalaxin-like 1 and Amgalaxin-like 2) encode larger and more divergent proteins. All three proteins are predicted to be extracellular and share common structural features, most notably the presence of repetitive motifs containing dicysteine residues. In situ hybridization reveals distinct, but partially overlapping, spatial expression of the genes in patterns consistent with distinct roles in calcification. Both of the Amgalaxin-like genes are expressed exclusively in the early stages of calcification, while Amgalaxin continues to be expressed in the adult, consistent with the situation in the coral Galaxea. Conclusion Comparisons with molluscs suggest functional convergence in the two groups; lustrin A/pearlin proteins may be the mollusc counterparts of galaxin, whereas the galaxin-like proteins combine characteristics of two distinct proteins involved in mollusc calcification. Database searches indicate that, although sequences with high similarity to the galaxins are restricted to the Scleractinia, more divergent members of this protein family are present in other cnidarians and some other metazoans. We suggest that ancestral galaxins may have been secondarily recruited to roles in calcification in the Triassic, when the Scleractinia first appeared. Understanding the evolution of the broader galaxin family will require wider sampling and expression analysis in a range of cnidarians and other animals. PMID:19638240

  16. Specializing on vulnerable habitat: Acropora selectivity among damselfish recruits and the risk of bleaching-induced habitat loss

    NASA Astrophysics Data System (ADS)

    Bonin, M. C.

    2012-03-01

    Coral reef habitats are increasingly being degraded and destroyed by a range of disturbances, most notably climate-induced coral bleaching. Habitat specialists, particularly those associated with susceptible coral species, are clearly among the most vulnerable to population decline or extinction. However, the degree of specialization on coral microhabitats is still unclear for one of the most ubiquitous, abundant and well studied of coral reef fish families—the damselfishes (Pomacentridae). Using high taxonomic resolution surveys of microhabitat use and availability, this study provides the first species-level description of patterns of Acropora selectivity among recruits of 10 damselfish species in order to determine their vulnerability to habitat degradation. In addition, surveys of the bleaching susceptibility of 16 branching coral species revealed which preferred recruitment microhabitats are at highest risk of decline as a result of chronic coral bleaching. Four species (i.e., Chrysiptera parasema, Pomacentrus moluccensis, Dascyllus melanurus and Chromis retrofasciata) were identified as highly vulnerable because they used only branching hard corals as recruitment habitat and primarily associated with only 2-4 coral species. The bleaching surveys revealed that five species of Acropora were highly susceptible to bleaching, with more than 50% of colonies either severely bleached or already dead. These highly susceptible corals included two of the preferred microhabitats of the specialist C. parasema and represented a significant proportion of its total recruitment microhabitat. In contrast, highly susceptible corals were rarely used by another specialist, P. moluccensis, suggesting that this species faces a lower risk of bleaching-induced habitat loss compared to C. parasema. As degradation to coral reef habitats continues, specialists will increasingly be forced to use alternative recruitment microhabitats, and this is likely to reduce population

  17. RNA-seq profiles of immune related genes in the staghorn coral Acropora cervicornis infected with white band disease.

    PubMed

    Libro, Silvia; Kaluziak, Stefan T; Vollmer, Steven V

    2013-01-01

    Coral diseases are among the most serious threats to coral reefs worldwide, yet most coral diseases remain poorly understood. How the coral host responds to pathogen infection is an area where very little is known. Here we used next-generation RNA-sequencing (RNA-seq) to produce a transcriptome-wide profile of the immune response of the Staghorn coral Acropora cervicornis to White Band Disease (WBD) by comparing infected versus healthy (asymptomatic) coral tissues. The transcriptome of A. cervicornis was assembled de novo from A-tail selected Illumina mRNA-seq data from whole coral tissues, and parsed bioinformatically into coral and non-coral transcripts using existing Acropora genomes in order to identify putative coral transcripts. Differentially expressed transcripts were identified in the coral and non-coral datasets to identify genes that were up- and down-regulated due to disease infection. RNA-seq analyses indicate that infected corals exhibited significant changes in gene expression across 4% (1,805 out of 47,748 transcripts) of the coral transcriptome. The primary response to infection included transcripts involved in macrophage-mediated pathogen recognition and ROS production, two hallmarks of phagocytosis, as well as key mediators of apoptosis and calcium homeostasis. The strong up-regulation of the enzyme allene oxide synthase-lipoxygenase suggests a key role of the allene oxide pathway in coral immunity. Interestingly, none of the three primary innate immune pathways--Toll-like receptors (TLR), Complement, and prophenoloxydase pathways, were strongly associated with the response of A. cervicornis to infection. Five-hundred and fifty differentially expressed non-coral transcripts were classified as metazoan (n = 84), algal or plant (n = 52), fungi (n = 24) and protozoans (n = 13). None of the 52 putative Symbiodinium or algal transcript had any clear immune functions indicating that the immune response is driven by the coral host, and not its algal

  18. RNA-seq profiles of immune related genes in the staghorn coral Acropora cervicornis infected with white band disease.

    PubMed

    Libro, Silvia; Kaluziak, Stefan T; Vollmer, Steven V

    2013-01-01

    Coral diseases are among the most serious threats to coral reefs worldwide, yet most coral diseases remain poorly understood. How the coral host responds to pathogen infection is an area where very little is known. Here we used next-generation RNA-sequencing (RNA-seq) to produce a transcriptome-wide profile of the immune response of the Staghorn coral Acropora cervicornis to White Band Disease (WBD) by comparing infected versus healthy (asymptomatic) coral tissues. The transcriptome of A. cervicornis was assembled de novo from A-tail selected Illumina mRNA-seq data from whole coral tissues, and parsed bioinformatically into coral and non-coral transcripts using existing Acropora genomes in order to identify putative coral transcripts. Differentially expressed transcripts were identified in the coral and non-coral datasets to identify genes that were up- and down-regulated due to disease infection. RNA-seq analyses indicate that infected corals exhibited significant changes in gene expression across 4% (1,805 out of 47,748 transcripts) of the coral transcriptome. The primary response to infection included transcripts involved in macrophage-mediated pathogen recognition and ROS production, two hallmarks of phagocytosis, as well as key mediators of apoptosis and calcium homeostasis. The strong up-regulation of the enzyme allene oxide synthase-lipoxygenase suggests a key role of the allene oxide pathway in coral immunity. Interestingly, none of the three primary innate immune pathways--Toll-like receptors (TLR), Complement, and prophenoloxydase pathways, were strongly associated with the response of A. cervicornis to infection. Five-hundred and fifty differentially expressed non-coral transcripts were classified as metazoan (n = 84), algal or plant (n = 52), fungi (n = 24) and protozoans (n = 13). None of the 52 putative Symbiodinium or algal transcript had any clear immune functions indicating that the immune response is driven by the coral host, and not its algal

  19. RNA-seq Profiles of Immune Related Genes in the Staghorn Coral Acropora cervicornis Infected with White Band Disease

    PubMed Central

    Libro, Silvia; Kaluziak, Stefan T.; Vollmer, Steven V.

    2013-01-01

    Coral diseases are among the most serious threats to coral reefs worldwide, yet most coral diseases remain poorly understood. How the coral host responds to pathogen infection is an area where very little is known. Here we used next-generation RNA-sequencing (RNA-seq) to produce a transcriptome-wide profile of the immune response of the Staghorn coral Acropora cervicornis to White Band Disease (WBD) by comparing infected versus healthy (asymptomatic) coral tissues. The transcriptome of A. cervicornis was assembled de novo from A-tail selected Illumina mRNA-seq data from whole coral tissues, and parsed bioinformatically into coral and non-coral transcripts using existing Acropora genomes in order to identify putative coral transcripts. Differentially expressed transcripts were identified in the coral and non-coral datasets to identify genes that were up- and down-regulated due to disease infection. RNA-seq analyses indicate that infected corals exhibited significant changes in gene expression across 4% (1,805 out of 47,748 transcripts) of the coral transcriptome. The primary response to infection included transcripts involved in macrophage-mediated pathogen recognition and ROS production, two hallmarks of phagocytosis, as well as key mediators of apoptosis and calcium homeostasis. The strong up-regulation of the enzyme allene oxide synthase-lipoxygenase suggests a key role of the allene oxide pathway in coral immunity. Interestingly, none of the three primary innate immune pathways - Toll-like receptors (TLR), Complement, and prophenoloxydase pathways, were strongly associated with the response of A. cervicornis to infection. Five-hundred and fifty differentially expressed non-coral transcripts were classified as metazoan (n = 84), algal or plant (n = 52), fungi (n = 24) and protozoans (n = 13). None of the 52 putative Symbiodinium or algal transcript had any clear immune functions indicating that the immune response is driven by the coral host, and not its algal

  20. A Connection between Colony Biomass and Death in Caribbean Reef-Building Corals

    PubMed Central

    Thornhill, Daniel J.; Rotjan, Randi D.; Todd, Brian D.; Chilcoat, Geoff C.; Iglesias-Prieto, Roberto; Kemp, Dustin W.; LaJeunesse, Todd C.; Reynolds, Jennifer McCabe; Schmidt, Gregory W.; Shannon, Thomas; Warner, Mark E.; Fitt, William K.

    2011-01-01

    Increased sea-surface temperatures linked to warming climate threaten coral reef ecosystems globally. To better understand how corals and their endosymbiotic dinoflagellates (Symbiodinium spp.) respond to environmental change, tissue biomass and Symbiodinium density of seven coral species were measured on various reefs approximately every four months for up to thirteen years in the Upper Florida Keys, United States (1994–2007), eleven years in the Exuma Cays, Bahamas (1995–2006), and four years in Puerto Morelos, Mexico (2003–2007). For six out of seven coral species, tissue biomass correlated with Symbiodinium density. Within a particular coral species, tissue biomasses and Symbiodinium densities varied regionally according to the following trends: Mexico≥Florida Keys≥Bahamas. Average tissue biomasses and symbiont cell densities were generally higher in shallow habitats (1–4 m) compared to deeper-dwelling conspecifics (12–15 m). Most colonies that were sampled displayed seasonal fluctuations in biomass and endosymbiont density related to annual temperature variations. During the bleaching episodes of 1998 and 2005, five out of seven species that were exposed to unusually high temperatures exhibited significant decreases in symbiotic algae that, in certain cases, preceded further decreases in tissue biomass. Following bleaching, Montastraea spp. colonies with low relative biomass levels died, whereas colonies with higher biomass levels survived. Bleaching- or disease-associated mortality was also observed in Acropora cervicornis colonies; compared to A. palmata, all A. cervicornis colonies experienced low biomass values. Such patterns suggest that Montastraea spp. and possibly other coral species with relatively low biomass experience increased susceptibility to death following bleaching or other stressors than do conspecifics with higher tissue biomass levels. PMID:22216307

  1. A connection between colony biomass and death in Caribbean reef-building corals.

    PubMed

    Thornhill, Daniel J; Rotjan, Randi D; Todd, Brian D; Chilcoat, Geoff C; Iglesias-Prieto, Roberto; Kemp, Dustin W; LaJeunesse, Todd C; Reynolds, Jennifer McCabe; Schmidt, Gregory W; Shannon, Thomas; Warner, Mark E; Fitt, William K

    2011-01-01

    Increased sea-surface temperatures linked to warming climate threaten coral reef ecosystems globally. To better understand how corals and their endosymbiotic dinoflagellates (Symbiodinium spp.) respond to environmental change, tissue biomass and Symbiodinium density of seven coral species were measured on various reefs approximately every four months for up to thirteen years in the Upper Florida Keys, United States (1994-2007), eleven years in the Exuma Cays, Bahamas (1995-2006), and four years in Puerto Morelos, Mexico (2003-2007). For six out of seven coral species, tissue biomass correlated with Symbiodinium density. Within a particular coral species, tissue biomasses and Symbiodinium densities varied regionally according to the following trends: Mexico≥Florida Keys≥Bahamas. Average tissue biomasses and symbiont cell densities were generally higher in shallow habitats (1-4 m) compared to deeper-dwelling conspecifics (12-15 m). Most colonies that were sampled displayed seasonal fluctuations in biomass and endosymbiont density related to annual temperature variations. During the bleaching episodes of 1998 and 2005, five out of seven species that were exposed to unusually high temperatures exhibited significant decreases in symbiotic algae that, in certain cases, preceded further decreases in tissue biomass. Following bleaching, Montastraea spp. colonies with low relative biomass levels died, whereas colonies with higher biomass levels survived. Bleaching- or disease-associated mortality was also observed in Acropora cervicornis colonies; compared to A. palmata, all A. cervicornis colonies experienced low biomass values. Such patterns suggest that Montastraea spp. and possibly other coral species with relatively low biomass experience increased susceptibility to death following bleaching or other stressors than do conspecifics with higher tissue biomass levels.

  2. A connection between colony biomass and death in Caribbean reef-building corals.

    PubMed

    Thornhill, Daniel J; Rotjan, Randi D; Todd, Brian D; Chilcoat, Geoff C; Iglesias-Prieto, Roberto; Kemp, Dustin W; LaJeunesse, Todd C; Reynolds, Jennifer McCabe; Schmidt, Gregory W; Shannon, Thomas; Warner, Mark E; Fitt, William K

    2011-01-01

    Increased sea-surface temperatures linked to warming climate threaten coral reef ecosystems globally. To better understand how corals and their endosymbiotic dinoflagellates (Symbiodinium spp.) respond to environmental change, tissue biomass and Symbiodinium density of seven coral species were measured on various reefs approximately every four months for up to thirteen years in the Upper Florida Keys, United States (1994-2007), eleven years in the Exuma Cays, Bahamas (1995-2006), and four years in Puerto Morelos, Mexico (2003-2007). For six out of seven coral species, tissue biomass correlated with Symbiodinium density. Within a particular coral species, tissue biomasses and Symbiodinium densities varied regionally according to the following trends: Mexico≥Florida Keys≥Bahamas. Average tissue biomasses and symbiont cell densities were generally higher in shallow habitats (1-4 m) compared to deeper-dwelling conspecifics (12-15 m). Most colonies that were sampled displayed seasonal fluctuations in biomass and endosymbiont density related to annual temperature variations. During the bleaching episodes of 1998 and 2005, five out of seven species that were exposed to unusually high temperatures exhibited significant decreases in symbiotic algae that, in certain cases, preceded further decreases in tissue biomass. Following bleaching, Montastraea spp. colonies with low relative biomass levels died, whereas colonies with higher biomass levels survived. Bleaching- or disease-associated mortality was also observed in Acropora cervicornis colonies; compared to A. palmata, all A. cervicornis colonies experienced low biomass values. Such patterns suggest that Montastraea spp. and possibly other coral species with relatively low biomass experience increased susceptibility to death following bleaching or other stressors than do conspecifics with higher tissue biomass levels. PMID:22216307

  3. Assessment of Host-Associated Genetic Differentiation among Phenotypically Divergent Populations of a Coral-Eating Gastropod across the Caribbean

    PubMed Central

    Johnston, Lyza; Miller, Margaret W.; Baums, Iliana B.

    2012-01-01

    Host-associated adaptation is emerging as a potential driver of population differentiation and speciation for marine organisms with major implications for ecosystem structure and function. Coralliophila abbreviata are corallivorous gastropods that live and feed on most of the reef-building corals in the tropical western Atlantic and Caribbean. Populations of C. abbreviata associated with the threatened acroporid corals, Acropora palmata and A. cervicornis, display different behavioral, morphological, demographic, and life-history characteristics than those that inhabit other coral host taxa, indicating that host-specific selective forces may be acting on C. abbreviata. Here, we used newly developed polymorphic microsatellite loci and mitochondrial cytochrome b sequence data to assess the population genetic structure, connectivity, and demographic history of C. abbreviata populations from three coral host taxa (A. palmata, Montastraea spp., Mycetophyllia spp.) and six geographic locations across the Caribbean. Analysis of molecular variance provided some evidence of weak and possibly geographically variable host-associated differentiation but no evidence of differentiation among sampling locations or major oceanographic regions, suggesting high gene flow across the Caribbean. Phylogenetic network and Bayesian clustering analyses supported a hypothesis of a single panmictic population as individuals failed to cluster by host or sampling location. Demographic analyses consistently supported a scenario of population expansion during the Pleistocene, a time of major carbonate reef development in the region. Although further study is needed to fully elucidate the interactive effects of host-associated selection and high gene flow in this system, our results have implications for local and regional community interactions and impact of predation on declining coral populations. PMID:23133600

  4. The chemical cue tetrabromopyrrole from a biofilm bacterium induces settlement of multiple Caribbean corals.

    PubMed

    Sneed, Jennifer M; Sharp, Koty H; Ritchie, Kimberly B; Paul, Valerie J

    2014-07-01

    Microbial biofilms induce larval settlement for some invertebrates, including corals; however, the chemical cues involved have rarely been identified. Here, we demonstrate the role of microbial biofilms in inducing larval settlement with the Caribbean coral Porites astreoides and report the first instance of a chemical cue isolated from a marine biofilm bacterium that induces complete settlement (attachment and metamorphosis) of Caribbean coral larvae. Larvae settled in response to natural biofilms, and the response was eliminated when biofilms were treated with antibiotics. A similar settlement response was elicited by monospecific biofilms of a single bacterial strain, Pseudoalteromonas sp. PS5, isolated from the surface biofilm of a crustose coralline alga. The activity of Pseudoalteromonas sp. PS5 was attributed to the production of a single compound, tetrabromopyrrole (TBP), which has been shown previously to induce metamorphosis without attachment in Pacific acroporid corals. In addition to inducing settlement of brooded larvae (P. astreoides), TBP also induced larval settlement for two broadcast-spawning species, Orbicella (formerly Montastraea) franksi and Acropora palmata, indicating that this compound may have widespread importance among Caribbean coral species. PMID:24850918

  5. Coral Reef Genomics: Developing tools for functional genomics ofcoral symbiosis

    SciTech Connect

    Schwarz, Jodi; Brokstein, Peter; Manohar, Chitra; Coffroth, MaryAlice; Szmant, Alina; Medina, Monica

    2005-03-01

    Symbioses between cnidarians and dinoflagellates in the genus Symbiodinium are widespread in the marine environment. The importance of this symbiosis to reef-building corals and reef nutrient and carbon cycles is well documented, but little is known about the mechanisms by which the partners establish and regulate the symbiosis. Because the dinoflagellate symbionts live inside the cells of their host coral, the interactions between the partners occur on cellular and molecular levels, as each partner alters the expression of genes and proteins to facilitate the partnership. These interactions can examined using high-throughput techniques that allow thousands of genes to be examined simultaneously. We are developing the groundwork so that we can use DNA microarray profiling to identify genes involved in the Montastraea faveolata and Acropora palmata symbioses. Here we report results from the initial steps in this microarray initiative, that is, the construction of cDNA libraries from 4 of 16 target stages, sequencing of 3450 cDNA clones to generate Expressed Sequenced Tags (ESTs), and annotation of the ESTs to identify candidate genes to include in the microarrays. An understanding of how the coral-dinoflagellate symbiosis is regulated will have implications for atmospheric and ocean sciences, conservation biology, the study and diagnosis of coral bleaching and disease, and comparative studies of animal-protest interactions.

  6. The chemical cue tetrabromopyrrole from a biofilm bacterium induces settlement of multiple Caribbean corals

    PubMed Central

    Sneed, Jennifer M.; Sharp, Koty H.; Ritchie, Kimberly B.; Paul, Valerie J.

    2014-01-01

    Microbial biofilms induce larval settlement for some invertebrates, including corals; however, the chemical cues involved have rarely been identified. Here, we demonstrate the role of microbial biofilms in inducing larval settlement with the Caribbean coral Porites astreoides and report the first instance of a chemical cue isolated from a marine biofilm bacterium that induces complete settlement (attachment and metamorphosis) of Caribbean coral larvae. Larvae settled in response to natural biofilms, and the response was eliminated when biofilms were treated with antibiotics. A similar settlement response was elicited by monospecific biofilms of a single bacterial strain, Pseudoalteromonas sp. PS5, isolated from the surface biofilm of a crustose coralline alga. The activity of Pseudoalteromonas sp. PS5 was attributed to the production of a single compound, tetrabromopyrrole (TBP), which has been shown previously to induce metamorphosis without attachment in Pacific acroporid corals. In addition to inducing settlement of brooded larvae (P. astreoides), TBP also induced larval settlement for two broadcast-spawning species, Orbicella (formerly Montastraea) franksi and Acropora palmata, indicating that this compound may have widespread importance among Caribbean coral species. PMID:24850918

  7. Growth anomalies on the coral genera Acropora and Porites are strongly associated with host density and human population size across the Indo-Pacific

    USGS Publications Warehouse

    Aeby, G.S.; Williams, G.J.; Franklin, E.C.; Haapkyla, J.; Harvell, C.D.; Neale, S.; Page, C.A.; Raymundo, L.; Vargas-Angel, B.; Willis, B.L.; Work, T.M.; Davy, S.K.

    2011-01-01

    Growth anomalies (GAs) are common, tumor-like diseases that can cause significant morbidity and decreased fecundity in the major Indo-Pacific reef-building coral genera, Acropora and Porites. GAs are unusually tractable for testing hypotheses about drivers of coral disease because of their pan-Pacific distributions, relatively high occurrence, and unambiguous ease of identification. We modeled multiple disease-environment associations that may underlie the prevalence of Acropora growth anomalies (AGA) (n = 304 surveys) and Porites growth anomalies (PGA) (n = 602 surveys) from across the Indo-Pacific. Nine predictor variables were modeled, including coral host abundance, human population size, and sea surface temperature and ultra-violet radiation anomalies. Prevalence of both AGAs and PGAs were strongly host density-dependent. PGAs additionally showed strong positive associations with human population size. Although this association has been widely posited, this is one of the first broad-scale studies unambiguously linking a coral disease with human population size. These results emphasize that individual coral diseases can show relatively distinct patterns of association with environmental predictors, even in similar diseases (growth anomalies) found on different host genera (Acropora vs. Porites). As human densities and environmental degradation increase globally, the prevalence of coral diseases like PGAs could increase accordingly, halted only perhaps by declines in host density below thresholds required for disease establishment.

  8. Cold induces acute stress but heat is ultimately more deleterious for the reef-building coral Acropora yongei

    PubMed Central

    Roth, Melissa S.; Goericke, Ralf; Deheyn, Dimitri D.

    2012-01-01

    Climate change driven increases in intensity and frequency of both hot and cold extreme events contribute to coral reef decline by causing widespread coral bleaching and mortality. Here, we show that hot and cold temperature changes cause distinct physiological responses on different time scales in reef-building corals. We exposed the branching coral Acropora yongei in individual aquaria to a ± 5°C temperature change. Compared to heat-treated corals, cold-treated corals initially show greater declines in growth and increases in photosynthetic pressure. However, after 2–3 weeks, cold-treated corals acclimate and show improvements in physiological state. In contrast, heat did not initially harm photochemical efficiency, but after a delay, photosynthetic pressure increased rapidly and corals experienced severe bleaching and cessation of growth. These results suggest that short-term cold temperature is more damaging for branching corals than short-term warm temperature, whereas long-term elevated temperature is more harmful than long-term depressed temperature. PMID:22355753

  9. Symbiodinium identity alters the temperature-dependent settlement behaviour of Acropora millepora coral larvae before the onset of symbiosis.

    PubMed

    Winkler, Natalia S; Pandolfi, John M; Sampayo, Eugenia M

    2015-02-22

    The global distribution of marine species, many of which disperse during the larval stages, is influenced by ocean temperature regimes. Here, we test how temperature and the coral symbionts (Symbiodinium) affect survival, symbiont uptake, settlement success and habitat choice of Acropora millepora larvae. Experiments were conducted at Heron Island (Australia), where larvae were exposed to 22.5, 24.5, 26.5 and 28.5°C. Within each temperature treatment, larvae were offered symbionts with distinct characteristics: (i) homologous Symbiodinium type C3, (ii) regionally homologous thermo-tolerant type D1, and (iii) heterologous thermo-tolerant type C15, as well as controls of (iv) un-filtered and (v) filtered seawater. Results show that lower instead of higher temperatures adversely affected recruitment by reducing larval survival and settlement. Low temperatures also reduced recruit habitat choice and initial symbiont densities, both of which impact on post-settlement survival. At lower temperatures, larvae increasingly settle away from preferred vertical surfaces and not on crustose coralline algae (CCA). Surprisingly, substrate preference to CCA was modified by the presence of specific symbiont genotypes that were present ex-hospite (outside the coral larvae). When different symbionts were mixed, the outcomes were non-additive, indicating that symbiont interactions modify the response. We propose that the observed influence of ex-hospite symbionts on settlement behaviour may have evolved through ecological facilitation and the study highlights the importance of biological processes during coral settlement. PMID:25589607

  10. Changes in microbial communities, photosynthesis and calcification of the coral Acropora gemmifera in response to ocean acidification

    PubMed Central

    Zhou, Guowei; Yuan, Tao; Cai, Lin; Zhang, Weipeng; Tian, Renmao; Tong, Haoya; Jiang, Lei; Yuan, Xiangcheng; Liu, Sheng; Qian, Peiyuan; Huang, Hui

    2016-01-01

    With the increasing anthropogenic CO2 concentration, ocean acidification (OA) can have dramatic effects on coral reefs. However, the effects of OA on coral physiology and the associated microbes remain largely unknown. In the present study, reef-building coral Acropora gemmifera collected from a reef flat with highly fluctuating environmental condition in the South China Sea were exposed to three levels of partial pressure of carbon dioxide (pCO2) (i.e., 421, 923, and 2070 μatm) for four weeks. The microbial community structures associated with A. gemmifera under these treatments were analyzed using 16S rRNA gene barcode sequencing. The results revealed that the microbial community associated with A. gemmifera was highly diverse at the genus level and dominated by Alphaproteobacteria. More importantly, the microbial community structure remained rather stable under different pCO2 treatments. Photosynthesis and calcification in A. gemmifera, as indicated by enrichment of δ18O and increased depletion of δ13C in the coral skeleton, were significantly impaired only at the high pCO2 (2070 μatm). These results suggest that A. gemmifera can maintain a high degree of stable microbial communities despite of significant physiological changes in response to extremely high pCO2. PMID:27786309

  11. Comparison of the effects of thermal stress and CO₂-driven acidified seawater on fertilization in coral Acropora digitifera.

    PubMed

    Iguchi, Akira; Suzuki, Atsushi; Sakai, Kazuhiko; Nojiri, Yukihiro

    2015-08-01

    Global warming (GW) and ocean acidification (OA) have been recognized as severe threats for reef-building corals that support coral reef ecosystems, but these effects on the early life history stage of corals are relatively unknown compared with the effects on calcification of adult corals. In this study, we evaluated the effects of thermal stress and CO2-driven acidified seawater on fertilization in a reef-building coral, Acropora digitifera. The fertilization rates of A. digitifera decreased in response to thermal stress compared with those under normal seawater conditions. In contrast, the changes of fertilization rates were not evident in the acidified seawater. Generalized Linear Mixed Model (GLMM) predicted that sperm/egg crosses and temperature were explanatory variables in the best-fitted model for the fertilization data. In the best model, interactions between thermal stress and acidified seawater on the fertilization rates were not selected. Our results suggested that coral fertilization is more sensitive to future GW than OA. Taking into consideration the previous finding that sperm motility of A. digitifera was decreased by acidified seawater, the decrease in coral cover followed by that of sperm concentration might cause the interacting effects of GW and OA on coral fertilization.

  12. Spawning and fertility of F1 hybrids of the coral genus Acropora in the Indo-Pacific

    NASA Astrophysics Data System (ADS)

    Isomura, Naoko; Iwao, Kenji; Morita, Masaya; Fukami, Hironobu

    2016-09-01

    The role of hybridization through multi-specific synchronous spawning in the evolution of reef-building corals has been discussed since the 1990s, particularly for the genus Acropora. However, F1 hybrids have been reported as common in only one case in the Caribbean, with no evidence of mechanisms that would allow continuous reproduction of the hybrids. In this study, we report for the first time the fecundity of two F1 hybrid colonies produced experimentally from two Indo-Pacific species, A. intermedia and A. florida. These F1 hybrids spawned at the same time as the parental corals. Backcrossing and F1 hybrid crossing were successful in both directions. Furthermore, more than 90% self-fertilization was achieved in an F1 hybrid, although it was negligible in the parental corals. While it is possible that the F1 hybrid was a chimera, these results suggest that some products of interspecific hybridization may persist as the offspring of self-fertilizing F1 hybrids.

  13. Gene expression patterns during the early stages of chemically induced larval metamorphosis and settlement of the coral Acropora millepora.

    PubMed

    Siboni, Nachshon; Abrego, David; Motti, Cherie A; Tebben, Jan; Harder, Tilmann

    2014-01-01

    The morphogenetic transition of motile coral larvae into sessile primary polyps is triggered and genetically programmed upon exposure to environmental biomaterials, such as crustose coralline algae (CCA) and bacterial biofilms. Although the specific chemical cues that trigger coral larval morphogenesis are poorly understood there is much more information available on the genes that play a role in this early life phase. Putative chemical cues from natural biomaterials yielded defined chemical samples that triggered different morphogenetic outcomes: an extract derived from a CCA-associated Pseudoalteromonas bacterium that induced metamorphosis, characterized by non-attached metamorphosed juveniles; and two fractions of the CCA Hydrolithon onkodes (Heydrich) that induced settlement, characterized by attached metamorphosed juveniles. In an effort to distinguish the genes involved in these two morphogenetic transitions, competent larvae of the coral Acropora millepora were exposed to these predictable cues and the expression profiles of 47 coral genes of interest (GOI) were investigated after only 1 hour of exposure using multiplex RT-qPCR. Thirty-two GOI were differentially expressed, indicating a putative role during the early regulation of morphogenesis. The most striking differences were observed for immunity-related genes, hypothesized to be involved in cell recognition and adhesion, and for fluorescent protein genes. Principal component analysis of gene expression profiles resulted in separation between the different morphogenetic cues and exposure times, and not only identified those genes involved in the early response but also those which influenced downstream biological changes leading to larval metamorphosis or settlement.

  14. Highly heterogeneous bacterial communities associated with the South China Sea reef corals Porites lutea, Galaxea fascicularis and Acropora millepora.

    PubMed

    Li, Jie; Chen, Qi; Zhang, Si; Huang, Hui; Yang, Jian; Tian, Xin-Peng; Long, Li-Juan

    2013-01-01

    Coral harbor diverse and specific bacteria play significant roles in coral holobiont function. Bacteria associated with three of the common and phylogenetically divergent reef-building corals in the South China Sea, Porites lutea, Galaxea fascicularis and Acropora millepora, were investigated using 454 barcoded-pyrosequencing. Three colonies of each species were sampled, and 16S rRNA gene libraries were constructed individually. Analysis of pyrosequencing libraries showed that bacterial communities associated with the three coral species were more diverse than previous estimates based on corals from the Caribbean Sea, Indo-Pacific reefs and the Red Sea. Three candidate phyla, including BRC1, OD1 and SR1, were found for the first time in corals. Bacterial communities were separated into three groups: P. lutea and G. fascicular, A. millepora and seawater. P. lutea and G. fascicular displayed more similar bacterial communities, and bacterial communities associated with A. millepora differed from the other two coral species. The three coral species shared only 22 OTUs, which were distributed in Alphaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, Chloroflexi, Actinobacteria, Acidobacteria and an unclassified bacterial group. The composition of bacterial communities within each colony of each coral species also showed variation. The relatively small common and large specific bacterial communities in these corals implies that bacterial associations may be structured by multiple factors at different scales and that corals may associate with microbes in terms of similar function, rather than identical species.

  15. Highly Heterogeneous Bacterial Communities Associated with the South China Sea Reef Corals Porites lutea, Galaxea fascicularis and Acropora millepora

    PubMed Central

    Li, Jie; Chen, Qi; Zhang, Si; Huang, Hui; Yang, Jian; Tian, Xin-Peng; Long, Li-Juan

    2013-01-01

    Coral harbor diverse and specific bacteria play significant roles in coral holobiont function. Bacteria associated with three of the common and phylogenetically divergent reef-building corals in the South China Sea, Porites lutea, Galaxea fascicularis and Acropora millepora, were investigated using 454 barcoded-pyrosequencing. Three colonies of each species were sampled, and 16S rRNA gene libraries were constructed individually. Analysis of pyrosequencing libraries showed that bacterial communities associated with the three coral species were more diverse than previous estimates based on corals from the Caribbean Sea, Indo-Pacific reefs and the Red Sea. Three candidate phyla, including BRC1, OD1 and SR1, were found for the first time in corals. Bacterial communities were separated into three groups: P. lutea and G. fascicular, A. millepora and seawater. P. lutea and G. fascicular displayed more similar bacterial communities, and bacterial communities associated with A. millepora differed from the other two coral species. The three coral species shared only 22 OTUs, which were distributed in Alphaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, Chloroflexi, Actinobacteria, Acidobacteria and an unclassified bacterial group. The composition of bacterial communities within each colony of each coral species also showed variation. The relatively small common and large specific bacterial communities in these corals implies that bacterial associations may be structured by multiple factors at different scales and that corals may associate with microbes in terms of similar function, rather than identical species. PMID:23940737

  16. Transcriptional Activation of c3 and hsp70 as Part of the Immune Response of Acropora millepora to Bacterial Challenges

    PubMed Central

    Brown, Tanya; Bourne, David; Rodriguez-Lanetty, Mauricio

    2013-01-01

    The impact of disease outbreaks on coral physiology represents an increasing concern for the fitness and resilience of reef ecosystems. Predicting the tolerance of corals to disease relies on an understanding of the coral immune response to pathogenic interactions. This study explored the transcriptional response of two putative immune genes (c3 and c-type lectin) and one stress response gene (hsp70) in the reef building coral, Acropora millepora challenged for 48 hours with bacterial strains, Vibrio coralliilyticus and Alteromonas sp. at concentrations of 106 cells ml-1. Coral fragments challenged with V. coralliilyticus appeared healthy while fragments challenged with Alteromonas sp. showed signs of tissue lesions after 48 hr. Coral-associated bacterial community profiles assessed using denaturing gradient gel electrophoresis changed after challenge by both bacterial strains with the Alteromonas sp. treatment demonstrating the greatest community shift. Transcriptional profiles of c3 and hsp70 increased at 24 hours and correlated with disease signs in the Alteromonas sp. treatment. The expression of hsp70 also showed a significant increase in V. coralliilyticus inoculated corals at 24 h suggesting that even in the absence of disease signs, the microbial inoculum activated a stress response in the coral. C-type lectin did not show a response to any of the bacterial treatments. Increase in gene expression of c3 and hsp70 in corals showing signs of disease indicates their potential involvement in immune and stress response to microbial challenges. PMID:23861754

  17. The transcriptomic response of the coral Acropora digitifera to a competent Symbiodinium strain: the symbiosome as an arrested early phagosome.

    PubMed

    Mohamed, A R; Cumbo, V; Harii, S; Shinzato, C; Chan, C X; Ragan, M A; Bourne, D G; Willis, B L; Ball, E E; Satoh, N; Miller, D J

    2016-07-01

    Despite the ecological significance of the relationship between reef-building corals and intracellular photosynthetic dinoflagellates of the genus Symbiodinium, very little is known about the molecular mechanisms involved in its establishment. Indeed, microarray-based analyses point to the conclusion that host gene expression is largely or completely unresponsive during the establishment of symbiosis with a competent strain of Symbiodinium. In this study, the use of Illumina RNA-Seq technology allowed detection of a transient period of differential expression involving a small number of genes (1073 transcripts; <3% of the transcriptome) 4 h after the exposure of Acropora digitifera planulae to a competent strain of Symbiodinium (a clade B strain). This phenomenon has not previously been detected as a consequence of both the lower sensitivity of the microarray approaches used and the sampling times used. The results indicate that complex changes occur, including transient suppression of mitochondrial metabolism and protein synthesis, but are also consistent with the hypothesis that the symbiosome is a phagosome that has undergone early arrest, raising the possibility of common mechanisms in the symbiotic interactions of corals and symbiotic sea anemones with their endosymbionts. PMID:27094992

  18. High potential for formation and persistence of chimeras following aggregated larval settlement in the broadcast spawning coral, Acropora millepora.

    PubMed

    Puill-Stephan, E; van Oppen, M J H; Pichavant-Rafini, K; Willis, B L

    2012-02-22

    In sessile modular marine invertebrates, chimeras can originate from fusions of closely settling larvae or of colonies that come into contact through growth or movement. While it has been shown that juveniles of brooding corals fuse under experimental conditions, chimera formation in broadcast spawning corals, the most abundant group of reef corals, has not been examined. This study explores the capacity of the broadcast spawning coral Acropora millepora to form chimeras under experimental conditions and to persist as chimeras in the field. Under experimental conditions, 1.5-fold more larvae settled in aggregations than solitarily, and analyses of nine microsatellite loci revealed that 50 per cent of juveniles tested harboured different genotypes within the same colony. Significantly, some chimeric colonies persisted for 23 months post-settlement, when the study ended. Genotypes within persisting chimeric colonies all showed a high level of relatedness, whereas rejecting colonies displayed variable levels of relatedness. The nearly threefold greater sizes of chimeras compared with solitary juveniles, from settlement through to at least three months, suggest that chimerism is likely to be an important strategy for maximizing survival of vulnerable early life-history stages of corals, although longer-term studies are required to more fully explore the potential benefits of chimerism. PMID:21752820

  19. Demographic history and asynchronous spawning shape genetic differentiation among populations of the hard coral Acropora tenuis in Western Australia.

    PubMed

    Rosser, Natalie L

    2016-05-01

    Genetic subdivision within populations can ultimately lead to the evolution of new species, and in populations of broadcast-spawners a potential facilitator of genetic subdivision is asynchronous reproduction. However, the factors that shape genetic variation in marine systems are complex and ambiguous, and ecological genetic structure may be influenced by the overriding signature of past demographic events. Here, the relative roles of the timing of reproduction and historical geography on the partitioning of genetic variation were examined in seven populations of the broadcast-spawning coral Acropora tenuis over 12° of latitude. The analysis of multiple loci (mitochondrial control region, two nuclear introns and six microsatellites) revealed significant genetic division between the most northern reef and all other reefs, suggesting that WA reefs were re-colonized from two different sources after the Pleistocene glaciation. Accompanying this pattern was significant genetic differentiation associated with different breeding seasons (spring and autumn), which was greatest in PaxC, in which there were two divergent lineages (ΦST=0.98). This is the second study to find divergent clades of PaxC associated with spring and autumn spawners, strengthening the suggestion of some selective connection to timing of reproduction in corals. This study reiterates the need to incorporate reproductive timing into population genetic studies of corals because it facilitates genetic differentiation; however, careful analysis of population genetic data is required to separate ecological and evolutionary processes. PMID:26876640

  20. Propagation of the threatened staghorn coral Acropora cervicornis: methods to minimize the impacts of fragment collection and maximize production

    NASA Astrophysics Data System (ADS)

    Lirman, D.; Thyberg, T.; Herlan, J.; Hill, C.; Young-Lahiff, C.; Schopmeyer, S.; Huntington, B.; Santos, R.; Drury, C.

    2010-09-01

    Coral reef restoration methods such as coral gardening are becoming increasingly considered as viable options to mitigate reef degradation and enhance recovery of depleted coral populations. In this study, we describe several aspects of the coral gardening approach that demonstrate this methodology is an effective way of propagating the threatened Caribbean staghorn coral Acropora cervicornis: (1) the growth of colonies within the nursery exceeded the growth rates of wild staghorn colonies in the same region; (2) the collection of branch tips did not result in any further mortality to the donor colonies beyond the coral removed for transplantation; (3) decreases in linear extension of the donor branches were only temporary and donor branches grew faster than control branches after an initial recovery period of approximately 3-6 weeks; (4) fragmentation did not affect the growth rates of non-donor branches within the same colony; (5) small branch tips experienced initial mortality due to handling and transportation but surviving tips grew well over time; and (6) when the growth of the branch tips is added to the regrowth of the fragmented donor branches, the new coral produced was 1.4-1.8 times more than new growth in undisturbed colonies. Based on these results, the collection of small (2.5-3.5 cm) branch tips was an effective propagation method for this branching coral species resulting in increased biomass accumulation and limited damage to parental stocks.

  1. Effects of seawater pH on growth and skeletal U/Ca ratios of Acropora digitifera coral polyps

    NASA Astrophysics Data System (ADS)

    Inoue, Mayuri; Suwa, Ryota; Suzuki, Atsushi; Sakai, Kazuhiko; Kawahata, Hodaka

    2011-06-01

    The impact of ocean acidification caused by the increasing atmospheric CO2 has been studied in marine calcifiers, including hermatypic corals. However, the effect of elevated pCO2 on the early developmental life-cycle stage of corals has been little studied. In this study, we reared polyps of Acropora digitifera in seawater at pHT 6.55, 7.31, 7.64, 7.77, and 8.03, controlled by CO2 bubbling. We measured the dry weights of polyp skeletons after the 40-d experiment to investigate the relationship between the seawater aragonite saturation state and polyp growth. In addition, we measured skeletal U/Ca ratio to estimate their pH dependence. Skeletal weights of coral polyps increased with the aragonite saturation state and reached an apparent saturation plateau above pH 7.77. U/Ca ratios had a strong inverse relationship with pH and a negligible relationship with skeletal growth rate (polyp weight), suggesting that skeletal U/Ca could be useful for reconstructing paleo-pH.

  2. Algal symbiont type affects gene expression in juveniles of the coral Acropora tenuis exposed to thermal stress.

    PubMed

    Yuyama, Ikuko; Harii, Saki; Hidaka, Michio

    2012-05-01

    Reef-building corals harbor symbiotic dinoflagellates, Symbiodinium spp., which are currently divided into several clades. The responses of corals associated with different Symbiodinium clades to thermal stress are not well understood, especially at a gene expression level. Juveniles of the coral Acropora tenuis inoculated with different algal types (clade A or D) were exposed to thermal stress and the expression levels of four putative stress-responsive genes, including genes coding green and red fluorescent proteins, an oxidative stress-responsive protein, and an ascorbic acid transporter, were analyzed by quantitative real-time PCR. The expression levels of the four genes decreased at high temperatures if juveniles were associated with clade A symbionts but increased if the symbionts were in clade D. The intensity of green fluorescence increased with temperature in clade D symbionts harboring juveniles, but not in juveniles associated with clade A symbionts. The present results suggest that genotypes of endosymbiotic algae affect the thermal stress responses of the coral juveniles.

  3. Spawning times, reproductive compatibilities and genetic structuring in the Acropora aspera group: evidence for natural hybridization and semi-permeable species boundaries in corals.

    PubMed

    Van Oppen, Madeleine J H; Willis, Bette L; Van Rheede, Teun; Miller, David J

    2002-08-01

    Species boundaries among five sympatric coral species of the Indo-Pacific Acropora aspera group were examined by a combination of in vitro breeding trials, comparisons of spawning times and DNA sequence analysis of ribosomal DNA internal transcribed spacer (rDNA ITS) and 5.8S regions. The breeding trials showed that reproductive compatibility exists between at least some colonies of all the species pairs tested, suggesting a large potential for natural hybridization and introgression. The Acropora ITS regions exhibited extremely high levels of variability (up to approximately 62% for ITS1, approximately 11% for 5.8S and approximately 43% for ITS2), but most of the variation was shared among four of the five species, A. millepora, A. papillare, A. pulchra and A. spathulata, consistent with extensive introgression. Phylogenetic analyses did not resolve these four species as distinct clusters across a wide biogeographic region stretching from the southern Great Barrier Reef to Papua New Guinea. However, most colonies of the fifth species, A. aspera, constituted a distinct clade in phylogenetic analyses. This is consistent with our observations of a semi-permeable temporal barrier involving differences in spawning times between this and the other four species. Although the majority of colonies of all five species generally spawned within 90 min of each other, in two out of four years, gametes were absent prior to mass spawning episodes from at least some A. aspera colonies. Hence, our data suggest that transient reproductive barriers may be the result of year-to-year variation in the date of spawning and that this difference in spawning time contributes to the genetic structure detected among Acropora species in this group. Occasional leakage through the reproductive barrier was confirmed by the observation of A. aspera xA. pulchra F1 hybrids, identified based on additivity of ITS sequences.

  4. Host Coenzyme Q Redox State Is an Early Biomarker of Thermal Stress in the Coral Acropora millepora

    PubMed Central

    Motti, Cherie A.; Miller, David J.; van Oppen, Madeleine J. H.

    2015-01-01

    Bleaching episodes caused by increasing seawater temperatures may induce mass coral mortality and are regarded as one of the biggest threats to coral reef ecosystems worldwide. The current consensus is that this phenomenon results from enhanced production of harmful reactive oxygen species (ROS) that disrupt the symbiosis between corals and their endosymbiotic dinoflagellates, Symbiodinium. Here, the responses of two important antioxidant defence components, the host coenzyme Q (CoQ) and symbiont plastoquinone (PQ) pools, are investigated for the first time in colonies of the scleractinian coral, Acropora millepora, during experimentally-induced bleaching under ecologically relevant conditions. Liquid chromatography-mass spectrometry (LC-MS) was used to quantify the states of these two pools, together with physiological parameters assessing the general state of the symbiosis (including photosystem II photochemical efficiency, chlorophyll concentration and Symbiodinium cell densities). The results show that the responses of the two antioxidant systems occur on different timescales: (i) the redox state of the Symbiodinium PQ pool remained stable until twelve days into the experiment, after which there was an abrupt oxidative shift; (ii) by contrast, an oxidative shift of approximately 10% had occurred in the host CoQ pool after 6 days of thermal stress, prior to significant changes in any other physiological parameter measured. Host CoQ pool oxidation is thus an early biomarker of thermal stress in corals, and this antioxidant pool is likely to play a key role in quenching thermally-induced ROS in the coral-algal symbiosis. This study adds to a growing body of work that indicates host cellular responses may precede the bleaching process and symbiont dysfunction. PMID:26426118

  5. In-situ effects of eutrophication and overfishing on physiology and bacterial diversity of the red sea coral Acropora hemprichii.

    PubMed

    Jessen, Christian; Villa Lizcano, Javier Felipe; Bayer, Till; Roder, Cornelia; Aranda, Manuel; Wild, Christian; Voolstra, Christian R

    2013-01-01

    Coral reefs of the Central Red Sea display a high degree of endemism, and are increasingly threatened by anthropogenic effects due to intense local coastal development measures. Overfishing and eutrophication are among the most significant local pressures on these reefs, but there is no information available about their potential effects on the associated microbial community. Therefore, we compared holobiont physiology and 16S-based bacterial communities of tissue and mucus of the hard coral Acropora hemprichii after 1 and 16 weeks of in-situ inorganic nutrient enrichment (via fertilizer diffusion) and/or herbivore exclusion (via caging) in an offshore reef of the Central Red Sea. Simulated eutrophication and/or overfishing treatments did not affect coral physiology with respect to coral respiration rates, chlorophyll a content, zooxanthellae abundance, or δ (15)N isotopic signatures. The bacterial community of A. hemprichii was rich and uneven, and diversity increased over time in all treatments. While distinct bacterial species were identified as a consequence of eutrophication, overfishing, or both, two bacterial species that could be classified to the genus Endozoicomonas were consistently abundant and constituted two thirds of bacteria in the coral. Several nitrogen-fixing and denitrifying bacteria were found in the coral specimens that were exposed to experimentally increased nutrients. However, no particular bacterial species was consistently associated with the coral under a given treatment and the single effects of manipulated eutrophication and overfishing could not predict the combined effect. Our data underlines the importance of conducting field studies in a holobiont framework, taking both, physiological and molecular measures into account. PMID:23630625

  6. In-situ Effects of Eutrophication and Overfishing on Physiology and Bacterial Diversity of the Red Sea Coral Acropora hemprichii

    PubMed Central

    Jessen, Christian; Villa Lizcano, Javier Felipe; Bayer, Till; Roder, Cornelia; Aranda, Manuel; Wild, Christian; Voolstra, Christian R

    2013-01-01

    Coral reefs of the Central Red Sea display a high degree of endemism, and are increasingly threatened by anthropogenic effects due to intense local coastal development measures. Overfishing and eutrophication are among the most significant local pressures on these reefs, but there is no information available about their potential effects on the associated microbial community. Therefore, we compared holobiont physiology and 16S-based bacterial communities of tissue and mucus of the hard coral Acropora hemprichii after 1 and 16 weeks of in-situ inorganic nutrient enrichment (via fertilizer diffusion) and/or herbivore exclusion (via caging) in an offshore reef of the Central Red Sea. Simulated eutrophication and/or overfishing treatments did not affect coral physiology with respect to coral respiration rates, chlorophyll a content, zooxanthellae abundance, or δ 15N isotopic signatures. The bacterial community of A. hemprichii was rich and uneven, and diversity increased over time in all treatments. While distinct bacterial species were identified as a consequence of eutrophication, overfishing, or both, two bacterial species that could be classified to the genus Endozoicomonas were consistently abundant and constituted two thirds of bacteria in the coral. Several nitrogen-fixing and denitrifying bacteria were found in the coral specimens that were exposed to experimentally increased nutrients. However, no particular bacterial species was consistently associated with the coral under a given treatment and the single effects of manipulated eutrophication and overfishing could not predict the combined effect. Our data underlines the importance of conducting field studies in a holobiont framework, taking both, physiological and molecular measures into account. PMID:23630625

  7. Cumulative Effects of Nutrient Enrichment and Elevated Temperature Compromise the Early Life History Stages of the Coral Acropora tenuis

    PubMed Central

    Noonan, Sam H. C.; Willis, Bette L.; Fabricius, Katharina E.; Negri, Andrew P.

    2016-01-01

    Inshore coral reefs are experiencing the combined pressures of excess nutrient availability associated with coastal activities and warming seawater temperatures. Both pressures are known to have detrimental effects on the early life history stages of hard corals, but studies of their combined effects on early demographic stages are lacking. We conducted a series of experiments to test the combined effects of nutrient enrichment (three levels) and elevated seawater temperature (up to five levels) on early life history stages of the inshore coral Acropora tenuis, a common species in the Indo-Pacific and Red Sea. Gamete fertilization, larval survivorship and larval settlement were all significantly reduced as temperature increased, but only fertilization was further affected by simultaneous nutrient enrichment. Combined high temperatures and nutrient enrichment affected fertilization in an additive manner, whereas embryo abnormalities increased synergistically. Higher than normal temperatures (32°C) increased coral juvenile growth rates 1.6-fold, but mortality also increased by 50%. The co-occurrence of nutrient enrichment with high temperatures reduced juvenile mortality to 36%, ameliorating temperature stress (antagonistic interaction). Overall, the types of effect (additive vs synergistic or antagonistic) and their magnitude varied among life stages. Gamete and embryo stages were more affected by temperature stress and, in some cases, also by nutrient enrichment than juveniles. The data suggest that coastal runoff events might exacerbate the impacts of warming temperatures on fertilization if these events co-occur during corals spawning. The cumulative impacts of simultaneous exposure to nutrient enrichment and elevated temperatures over all early life history stages increases the likelihood for failure of larval supply and recruitment for this coral species. Our results suggest that improving the water quality of river discharges into coastal areas might help to

  8. Possible natural hybridization of two morphologically distinct species of Acropora (Cnidaria, Scleractinia) in the Pacific: fertilization and larval survival rates.

    PubMed

    Isomura, Naoko; Iwao, Kenji; Fukami, Hironobu

    2013-01-01

    Natural hybridization of corals in the Indo-Pacific has been considered rather rare. However, field studies have observed many corals with intermediate interspecific or unusual morphologies. Given that the existence of F1 hybrids with intermediate interspecific morphologies has been proven in the Caribbean, hybrids may also inhabit the Indo-Pacific and occur more frequently than expected. In this study, we focused on two morphologically different species, Acropora florida and A. intermedia, and performed crossing experiments at Akajima Island, Japan. Results showed that these species could hybridize in both directions via eggs and sperm, but that fertilization rates significantly differed according to which species provided eggs. These results are similar to those reported from the Caribbean. Although all embryos developed normally to the planular larval stage, the developmental processes of some hybrid embryos were delayed by approximately 1 h compared with conspecific embryos, suggesting that fertilization occurred 1 h later in interspecific crosses than in intraspecific crosses. More successful hybridization could occur under conditions with low numbers of conspecific colonies. Additionally, a comparison of survival rates between hybrid and intraspecific larvae revealed that intra- and interspecific larvae produced from eggs of A. florida survived for significantly longer than those produced from eggs of A. intermedia. Considering these data, under specific conditions, hybrids can be expected to be produced and survive in nature in the Pacific. Furthermore, we identified one colony with intermediate morphology between A. florida and A. intermedia in the field. This colony was fertilized only by eggs of A. florida, with high fertilization rates, suggesting that this colony would be a hybrid of these two species and might be backcrossed.

  9. Host Coenzyme Q Redox State Is an Early Biomarker of Thermal Stress in the Coral Acropora millepora.

    PubMed

    Lutz, Adrian; Raina, Jean-Baptiste; Motti, Cherie A; Miller, David J; van Oppen, Madeleine J H

    2015-01-01

    Bleaching episodes caused by increasing seawater temperatures may induce mass coral mortality and are regarded as one of the biggest threats to coral reef ecosystems worldwide. The current consensus is that this phenomenon results from enhanced production of harmful reactive oxygen species (ROS) that disrupt the symbiosis between corals and their endosymbiotic dinoflagellates, Symbiodinium. Here, the responses of two important antioxidant defence components, the host coenzyme Q (CoQ) and symbiont plastoquinone (PQ) pools, are investigated for the first time in colonies of the scleractinian coral, Acropora millepora, during experimentally-induced bleaching under ecologically relevant conditions. Liquid chromatography-mass spectrometry (LC-MS) was used to quantify the states of these two pools, together with physiological parameters assessing the general state of the symbiosis (including photosystem II photochemical efficiency, chlorophyll concentration and Symbiodinium cell densities). The results show that the responses of the two antioxidant systems occur on different timescales: (i) the redox state of the Symbiodinium PQ pool remained stable until twelve days into the experiment, after which there was an abrupt oxidative shift; (ii) by contrast, an oxidative shift of approximately 10% had occurred in the host CoQ pool after 6 days of thermal stress, prior to significant changes in any other physiological parameter measured. Host CoQ pool oxidation is thus an early biomarker of thermal stress in corals, and this antioxidant pool is likely to play a key role in quenching thermally-induced ROS in the coral-algal symbiosis. This study adds to a growing body of work that indicates host cellular responses may precede the bleaching process and symbiont dysfunction.

  10. Cumulative Effects of Nutrient Enrichment and Elevated Temperature Compromise the Early Life History Stages of the Coral Acropora tenuis.

    PubMed

    Humanes, Adriana; Noonan, Sam H C; Willis, Bette L; Fabricius, Katharina E; Negri, Andrew P

    2016-01-01

    Inshore coral reefs are experiencing the combined pressures of excess nutrient availability associated with coastal activities and warming seawater temperatures. Both pressures are known to have detrimental effects on the early life history stages of hard corals, but studies of their combined effects on early demographic stages are lacking. We conducted a series of experiments to test the combined effects of nutrient enrichment (three levels) and elevated seawater temperature (up to five levels) on early life history stages of the inshore coral Acropora tenuis, a common species in the Indo-Pacific and Red Sea. Gamete fertilization, larval survivorship and larval settlement were all significantly reduced as temperature increased, but only fertilization was further affected by simultaneous nutrient enrichment. Combined high temperatures and nutrient enrichment affected fertilization in an additive manner, whereas embryo abnormalities increased synergistically. Higher than normal temperatures (32°C) increased coral juvenile growth rates 1.6-fold, but mortality also increased by 50%. The co-occurrence of nutrient enrichment with high temperatures reduced juvenile mortality to 36%, ameliorating temperature stress (antagonistic interaction). Overall, the types of effect (additive vs synergistic or antagonistic) and their magnitude varied among life stages. Gamete and embryo stages were more affected by temperature stress and, in some cases, also by nutrient enrichment than juveniles. The data suggest that coastal runoff events might exacerbate the impacts of warming temperatures on fertilization if these events co-occur during corals spawning. The cumulative impacts of simultaneous exposure to nutrient enrichment and elevated temperatures over all early life history stages increases the likelihood for failure of larval supply and recruitment for this coral species. Our results suggest that improving the water quality of river discharges into coastal areas might help to

  11. Influence of fish grazing and sedimentation on the early post-settlement survival of the tabular coral Acropora cytherea

    NASA Astrophysics Data System (ADS)

    Trapon, M. L.; Pratchett, M. S.; Hoey, A. S.; Baird, A. H.

    2013-12-01

    Processes operating in the early life stages of corals are critical in ultimately establishing patterns of adult abundance. Mortality, in particular, is assumed to be very high during the first few months to years post-settlement, but the sources of this mortality are largely unknown. This study quantified early post-settlement survival for Acropora cytherea, spawned and reared in captivity and settled onto terracotta tiles. Replicate tiles were then deployed in the field at Lizard Island, in northern section of the Great Barrier Reef to examine the effects of grazing and sedimentation on survival of corals in two different habitats, the exposed reef crest and sheltered back reef. Overall, survivorship was broadly comparable between habitats, ranging from 37.7 to 64.5 % per month on the exposed reef crest and 53.1-64.3 % on the sheltered back reef. On the reef crest, the exclusion of herbivores increased survivorship by 22.4 %, from 42.1 to 64.5 % per month. Moreover, survivorship within the reef crest was negatively correlated with the density of parrotfish feeding scars on tiles after 4 weeks. In contrast, the exclusion of herbivores had no detectable effect on survivorship within the back reef, and no feeding scars were observed on tiles in this habitat. Difference in grazing-induced mortality between habitats is most likely related to differences in herbivore size and abundance, with parrotfish biomass being 5.5-fold greater on the reef crest than the back reef. Surprisingly, tile orientation had no effect on survivorship of A. cytherea in either habitat, despite a marked difference in the sediment cover on vertical (0 %) versus horizontal tiles (30 %) in the back reef. This is in marked contrast to previous studies that have reported sedimentation is a major cause of early post-settlement mortality in corals. Clearly, processes that cause mortality of newly settled corals, such as grazing and sedimentation, vary spatially.

  12. Using bacterial extract along with differential gene expression in Acropora millepora larvae to decouple the processes of attachment and metamorphosis.

    PubMed

    Siboni, Nachshon; Abrego, David; Seneca, Francois; Motti, Cherie A; Andreakis, Nikos; Tebben, Jan; Blackall, Linda L; Harder, Tilmann

    2012-01-01

    Biofilms of the bacterium Pseudoalteromonas induce metamorphosis of acroporid coral larvae. The bacterial metabolite tetrabromopyrrole (TBP), isolated from an extract of Pseudoalteromonas sp. associated with the crustose coralline alga (CCA) Neogoniolithon fosliei, induced coral larval metamorphosis (100%) with little or no attachment (0-2%). To better understand the molecular events and mechanisms underpinning the induction of Acropora millepora larval metamorphosis, including cell proliferation, apoptosis, differentiation, migration, adhesion and biomineralisation, two novel coral gene expression assays were implemented. These involved the use of reverse-transcriptase quantitative PCR (RT-qPCR) and employed 47 genes of interest (GOI), selected based on putative roles in the processes of settlement and metamorphosis. Substantial differences in transcriptomic responses of GOI were detected following incubation of A. millepora larvae with a threshold concentration and 10-fold elevated concentration of TBP-containing extracts of Pseudoalteromonas sp. The notable and relatively abrupt changes of the larval body structure during metamorphosis correlated, at the molecular level, with significant differences (p<0.05) in gene expression profiles of 24 GOI, 12 hours post exposure. Fourteen of those GOI also presented differences in expression (p<0.05) following exposure to the threshold concentration of bacterial TBP-containing extract. The specificity of the bacterial TBP-containing extract to induce the metamorphic stage in A. millepora larvae without attachment, using a robust, low cost, accurate, ecologically relevant and highly reproducible RT-qPCR assay, allowed partially decoupling of the transcriptomic processes of attachment and metamorphosis. The bacterial TBP-containing extract provided a unique opportunity to monitor the regulation of genes exclusively involved in the process of metamorphosis, contrasting previous gene expression studies that utilized cues

  13. Host Coenzyme Q Redox State Is an Early Biomarker of Thermal Stress in the Coral Acropora millepora.

    PubMed

    Lutz, Adrian; Raina, Jean-Baptiste; Motti, Cherie A; Miller, David J; van Oppen, Madeleine J H

    2015-01-01

    Bleaching episodes caused by increasing seawater temperatures may induce mass coral mortality and are regarded as one of the biggest threats to coral reef ecosystems worldwide. The current consensus is that this phenomenon results from enhanced production of harmful reactive oxygen species (ROS) that disrupt the symbiosis between corals and their endosymbiotic dinoflagellates, Symbiodinium. Here, the responses of two important antioxidant defence components, the host coenzyme Q (CoQ) and symbiont plastoquinone (PQ) pools, are investigated for the first time in colonies of the scleractinian coral, Acropora millepora, during experimentally-induced bleaching under ecologically relevant conditions. Liquid chromatography-mass spectrometry (LC-MS) was used to quantify the states of these two pools, together with physiological parameters assessing the general state of the symbiosis (including photosystem II photochemical efficiency, chlorophyll concentration and Symbiodinium cell densities). The results show that the responses of the two antioxidant systems occur on different timescales: (i) the redox state of the Symbiodinium PQ pool remained stable until twelve days into the experiment, after which there was an abrupt oxidative shift; (ii) by contrast, an oxidative shift of approximately 10% had occurred in the host CoQ pool after 6 days of thermal stress, prior to significant changes in any other physiological parameter measured. Host CoQ pool oxidation is thus an early biomarker of thermal stress in corals, and this antioxidant pool is likely to play a key role in quenching thermally-induced ROS in the coral-algal symbiosis. This study adds to a growing body of work that indicates host cellular responses may precede the bleaching process and symbiont dysfunction. PMID:26426118

  14. Regulation of Apoptotic Mediators Reveals Dynamic Responses to Thermal Stress in the Reef Building Coral Acropora millepora

    PubMed Central

    Pernice, Mathieu; Dunn, Simon R.; Miard, Thomas; Dufour, Sylvie; Dove, Sophie; Hoegh-Guldberg, Ove

    2011-01-01

    Background Mass coral bleaching is increasing in scale and frequency across the world's coral reefs and is being driven primarily by increased levels of thermal stress arising from global warming. In order to understand the impacts of projected climate change upon corals reefs, it is important to elucidate the underlying cellular mechanisms that operate during coral bleaching and subsequent mortality. In this respect, increased apoptotic cell death activity is an important cellular process that is associated with the breakdown of the mutualistic symbiosis between the cnidarian host and their dinoflagellate symbionts. Methodology/Principal Findings The present study reports the impacts of different stressors (colchicine and heat stress) on three phases of apoptosis: (i) the potential initiation by differential expression of Bcl-2 members, (ii) the execution of apoptotic events by activation of caspase 3-like proteases and (iii) and finally, the cell disposal indicated by DNA fragmentation in the reef building coral Acropora millepora. In corals incubated with colchicine, an increase in caspase 3-like activity and DNA fragmentation was associated with a relative down-regulation of Bcl-2, suggesting that the initiation of apoptosis may be mediated by the suppression of an anti-apoptotic mechanism. In contrast, in the early steps of heat stress, the induction of caspase-dependent apoptosis was related to a relative up-regulation of Bcl-2 consecutively followed by a delayed decrease in apoptosis activity. Conclusions/Significance In the light of these results, we propose a model of heat stress in coral hosts whereby increasing temperatures engage activation of caspase 3-dependent apoptosis in cells designated for termination, but also the onset of a delayed protective response involving overexpression of Bcl-2 in surviving cells. This mitigating response to thermal stress could conceivably be an important regulatory mechanism for cell survival in corals exposed to

  15. Modeled connectivity of Acropora millepora populations from reefs of the Spratly Islands and the greater South China Sea

    NASA Astrophysics Data System (ADS)

    Dorman, Jeffrey G.; Castruccio, Frederic S.; Curchitser, Enrique N.; Kleypas, Joan A.; Powell, Thomas M.

    2016-03-01

    The Spratly Island archipelago is a remote network of coral reefs and islands in the South China Sea that is a likely source of coral larvae to the greater region, but about which little is known. Using a particle-tracking model driven by oceanographic data from the Coral Triangle region, we simulated both spring and fall spawning events of Acropora millepora, a common coral species, over a 46-yr period (1960-2005). Simulated population biology of A. millepora included the acquisition and loss of competency, settlement over appropriate benthic habitat, and mortality based on experimental data. The simulations aimed to provide insights into the connectivity of reefs within the Spratly Islands, the settlement of larvae on reefs of the greater South China Sea, and the potential dispersal range of reef organisms from the Spratly Islands. Results suggest that (1) the Spratly Islands may be a significant source of A. millepora larvae for the Palawan reefs (Philippines) and some of the most isolated reefs of the South China Sea; and (2) the relatively isolated western Spratly Islands have limited source reefs supplying them with larvae and fewer of their larvae successfully settling on other reefs. Examination of particle dispersal without biology (settlement and mortality) suggests that larval connectivity is possible throughout the South China Sea and into the Coral Triangle region. Strong differences in the spring versus fall larval connectivity and dispersal highlight the need for a greater understanding of spawning dynamics of the region. This study confirms that the Spratly Islands are likely an important source of larvae for the South China Sea and Coral Triangle region.

  16. The Skeletal Proteome of the Coral Acropora millepora: The Evolution of Calcification by Co-Option and Domain Shuffling

    PubMed Central

    Ramos-Silva, Paula; Kaandorp, Jaap; Huisman, Lotte; Marie, Benjamin; Zanella-Cléon, Isabelle; Guichard, Nathalie; Miller, David J.; Marin, Frédéric

    2013-01-01

    In corals, biocalcification is a major function that may be drastically affected by ocean acidification (OA). Scleractinian corals grow by building up aragonitic exoskeletons that provide support and protection for soft tissues. Although this process has been extensively studied, the molecular basis of biocalcification is poorly understood. Notably lacking is a comprehensive catalog of the skeleton-occluded proteins—the skeletal organic matrix proteins (SOMPs) that are thought to regulate the mineral deposition. Using a combination of proteomics and transcriptomics, we report the first survey of such proteins in the staghorn coral Acropora millepora. The organic matrix (OM) extracted from the coral skeleton was analyzed by mass spectrometry and bioinformatics, enabling the identification of 36 SOMPs. These results provide novel insights into the molecular basis of coral calcification and the macroevolution of metazoan calcifying systems, whereas establishing a platform for studying the impact of OA at molecular level. Besides secreted proteins, extracellular regions of transmembrane proteins are also present, suggesting a close control of aragonite deposition by the calicoblastic epithelium. In addition to the expected SOMPs (Asp/Glu-rich, galaxins), the skeletal repertoire included several proteins containing known extracellular matrix domains. From an evolutionary perspective, the number of coral-specific proteins is low, many SOMPs having counterparts in the noncalcifying cnidarians. Extending the comparison with the skeletal OM proteomes of other metazoans allowed the identification of a pool of functional domains shared between phyla. These data suggest that co-option and domain shuffling may be general mechanisms by which the trait of calcification has evolved. PMID:23765379

  17. High natural gene expression variation in the reef-building coral Acropora millepora: potential for acclimative and adaptive plasticity

    PubMed Central

    2013-01-01

    Background Ecosystems worldwide are suffering the consequences of anthropogenic impact. The diverse ecosystem of coral reefs, for example, are globally threatened by increases in sea surface temperatures due to global warming. Studies to date have focused on determining genetic diversity, the sequence variability of genes in a species, as a proxy to estimate and predict the potential adaptive response of coral populations to environmental changes linked to climate changes. However, the examination of natural gene expression variation has received less attention. This variation has been implicated as an important factor in evolutionary processes, upon which natural selection can act. Results We acclimatized coral nubbins from six colonies of the reef-building coral Acropora millepora to a common garden in Heron Island (Great Barrier Reef, GBR) for a period of four weeks to remove any site-specific environmental effects on the physiology of the coral nubbins. By using a cDNA microarray platform, we detected a high level of gene expression variation, with 17% (488) of the unigenes differentially expressed across coral nubbins of the six colonies (jsFDR-corrected, p < 0.01). Among the main categories of biological processes found differentially expressed were transport, translation, response to stimulus, oxidation-reduction processes, and apoptosis. We found that the transcriptional profiles did not correspond to the genotype of the colony characterized using either an intron of the carbonic anhydrase gene or microsatellite loci markers. Conclusion Our results provide evidence of the high inter-colony variation in A. millepora at the transcriptomic level grown under a common garden and without a correspondence with genotypic identity. This finding brings to our attention the importance of taking into account natural variation between reef corals when assessing experimental gene expression differences. The high transcriptional variation detected in this study is

  18. In-situ effects of eutrophication and overfishing on physiology and bacterial diversity of the red sea coral Acropora hemprichii.

    PubMed

    Jessen, Christian; Villa Lizcano, Javier Felipe; Bayer, Till; Roder, Cornelia; Aranda, Manuel; Wild, Christian; Voolstra, Christian R

    2013-01-01

    Coral reefs of the Central Red Sea display a high degree of endemism, and are increasingly threatened by anthropogenic effects due to intense local coastal development measures. Overfishing and eutrophication are among the most significant local pressures on these reefs, but there is no information available about their potential effects on the associated microbial community. Therefore, we compared holobiont physiology and 16S-based bacterial communities of tissue and mucus of the hard coral Acropora hemprichii after 1 and 16 weeks of in-situ inorganic nutrient enrichment (via fertilizer diffusion) and/or herbivore exclusion (via caging) in an offshore reef of the Central Red Sea. Simulated eutrophication and/or overfishing treatments did not affect coral physiology with respect to coral respiration rates, chlorophyll a content, zooxanthellae abundance, or δ (15)N isotopic signatures. The bacterial community of A. hemprichii was rich and uneven, and diversity increased over time in all treatments. While distinct bacterial species were identified as a consequence of eutrophication, overfishing, or both, two bacterial species that could be classified to the genus Endozoicomonas were consistently abundant and constituted two thirds of bacteria in the coral. Several nitrogen-fixing and denitrifying bacteria were found in the coral specimens that were exposed to experimentally increased nutrients. However, no particular bacterial species was consistently associated with the coral under a given treatment and the single effects of manipulated eutrophication and overfishing could not predict the combined effect. Our data underlines the importance of conducting field studies in a holobiont framework, taking both, physiological and molecular measures into account.

  19. Using Bacterial Extract along with Differential Gene Expression in Acropora millepora Larvae to Decouple the Processes of Attachment and Metamorphosis

    PubMed Central

    Siboni, Nachshon; Abrego, David; Seneca, Francois; Motti, Cherie A.; Andreakis, Nikos; Tebben, Jan; Blackall, Linda L.; Harder, Tilmann

    2012-01-01

    Biofilms of the bacterium Pseudoalteromonas induce metamorphosis of acroporid coral larvae. The bacterial metabolite tetrabromopyrrole (TBP), isolated from an extract of Pseudoalteromonas sp. associated with the crustose coralline alga (CCA) Neogoniolithon fosliei, induced coral larval metamorphosis (100%) with little or no attachment (0–2%). To better understand the molecular events and mechanisms underpinning the induction of Acropora millepora larval metamorphosis, including cell proliferation, apoptosis, differentiation, migration, adhesion and biomineralisation, two novel coral gene expression assays were implemented. These involved the use of reverse-transcriptase quantitative PCR (RT-qPCR) and employed 47 genes of interest (GOI), selected based on putative roles in the processes of settlement and metamorphosis. Substantial differences in transcriptomic responses of GOI were detected following incubation of A. millepora larvae with a threshold concentration and 10-fold elevated concentration of TBP-containing extracts of Pseudoalteromonas sp. The notable and relatively abrupt changes of the larval body structure during metamorphosis correlated, at the molecular level, with significant differences (p<0.05) in gene expression profiles of 24 GOI, 12 hours post exposure. Fourteen of those GOI also presented differences in expression (p<0.05) following exposure to the threshold concentration of bacterial TBP-containing extract. The specificity of the bacterial TBP-containing extract to induce the metamorphic stage in A. millepora larvae without attachment, using a robust, low cost, accurate, ecologically relevant and highly reproducible RT-qPCR assay, allowed partially decoupling of the transcriptomic processes of attachment and metamorphosis. The bacterial TBP-containing extract provided a unique opportunity to monitor the regulation of genes exclusively involved in the process of metamorphosis, contrasting previous gene expression studies that utilized cues

  20. Developmental Progression in the Coral Acropora digitifera Is Controlled by Differential Expression of Distinct Regulatory Gene Networks

    PubMed Central

    Reyes-Bermudez, Alejandro; Villar-Briones, Alejandro; Ramirez-Portilla, Catalina; Hidaka, Michio; Mikheyev, Alexander S.

    2016-01-01

    Corals belong to the most basal class of the Phylum Cnidaria, which is considered the sister group of bilaterian animals, and thus have become an emerging model to study the evolution of developmental mechanisms. Although cell renewal, differentiation, and maintenance of pluripotency are cellular events shared by multicellular animals, the cellular basis of these fundamental biological processes are still poorly understood. To understand how changes in gene expression regulate morphogenetic transitions at the base of the eumetazoa, we performed quantitative RNA-seq analysis during Acropora digitifera’s development. We collected embryonic, larval, and adult samples to characterize stage-specific transcription profiles, as well as broad expression patterns. Transcription profiles reconstructed development revealing two main expression clusters. The first cluster grouped blastula and gastrula and the second grouped subsequent developmental time points. Consistently, we observed clear differences in gene expression between early and late developmental transitions, with higher numbers of differentially expressed genes and fold changes around gastrulation. Furthermore, we identified three coexpression clusters that represented discrete gene expression patterns. During early transitions, transcriptional networks seemed to regulate cellular fate and morphogenesis of the larval body. In late transitions, these networks seemed to play important roles preparing planulae for switch in lifestyle and regulation of adult processes. Although developmental progression in A. digitifera is regulated to some extent by differential coexpression of well-defined gene networks, stage-specific transcription profiles appear to be independent entities. While negative regulation of transcription is predominant in early development, cell differentiation was upregulated in larval and adult stages. PMID:26941230

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Occupation Dynamics and Impacts of Damselfish Territoriality on Recovering Populations of the Threatened Staghorn Coral, Acropora cervicornis

    PubMed Central

    Schopmeyer, Stephanie A.; Lirman, Diego

    2015-01-01

    Large-scale coral reef restoration is needed to help recover structure and function of degraded coral reef ecosystems and mitigate continued coral declines. In situ coral propagation and reef restoration efforts have scaled up significantly in past decades, particularly for the threatened Caribbean staghorn coral, Acropora cervicornis, but little is known about the role that native competitors and predators, such as farming damselfishes, have on the success of restoration. Steep declines in A. cervicornis abundance may have concentrated the negative impacts of damselfish algal farming on a much lower number of coral prey/colonies, thus creating a significant threat to the persistence and recovery of depleted coral populations. This is the first study to document the prevalence of resident damselfishes and negative effects of algal lawns on A. cervicornis along the Florida Reef Tract (FRT). Impacts of damselfish lawns on A. cervicornis colonies were more prevalent (21.6% of colonies) than those of other sources of mortality (i.e., disease (1.6%), algal/sponge overgrowth (5.6%), and corallivore predation (7.9%)), and damselfish activities caused the highest levels of tissue mortality (34.6%) among all coral stressors evaluated. The probability of damselfish occupation increased as coral colony size and complexity increased and coral growth rates were significantly lower in colonies with damselfish lawns (15.4 vs. 29.6 cm per year). Reduced growth and mortality of existing A. cervicornis populations may have a significant effect on population dynamics by potentially reducing important genetic diversity and the reproductive potential of depleted populations. On a positive note, however, the presence of resident damselfishes decreased predation by other corallivores, such as Coralliophila and Hermodice, and may offset some negative impacts caused by algal farming. While most negative impacts of damselfishes identified in this study affected large individual colonies and

  3. Occupation Dynamics and Impacts of Damselfish Territoriality on Recovering Populations of the Threatened Staghorn Coral, Acropora cervicornis.

    PubMed

    Schopmeyer, Stephanie A; Lirman, Diego

    2015-01-01

    Large-scale coral reef restoration is needed to help recover structure and function of degraded coral reef ecosystems and mitigate continued coral declines. In situ coral propagation and reef restoration efforts have scaled up significantly in past decades, particularly for the threatened Caribbean staghorn coral, Acropora cervicornis, but little is known about the role that native competitors and predators, such as farming damselfishes, have on the success of restoration. Steep declines in A. cervicornis abundance may have concentrated the negative impacts of damselfish algal farming on a much lower number of coral prey/colonies, thus creating a significant threat to the persistence and recovery of depleted coral populations. This is the first study to document the prevalence of resident damselfishes and negative effects of algal lawns on A. cervicornis along the Florida Reef Tract (FRT). Impacts of damselfish lawns on A. cervicornis colonies were more prevalent (21.6% of colonies) than those of other sources of mortality (i.e., disease (1.6%), algal/sponge overgrowth (5.6%), and corallivore predation (7.9%)), and damselfish activities caused the highest levels of tissue mortality (34.6%) among all coral stressors evaluated. The probability of damselfish occupation increased as coral colony size and complexity increased and coral growth rates were significantly lower in colonies with damselfish lawns (15.4 vs. 29.6 cm per year). Reduced growth and mortality of existing A. cervicornis populations may have a significant effect on population dynamics by potentially reducing important genetic diversity and the reproductive potential of depleted populations. On a positive note, however, the presence of resident damselfishes decreased predation by other corallivores, such as Coralliophila and Hermodice, and may offset some negative impacts caused by algal farming. While most negative impacts of damselfishes identified in this study affected large individual colonies and

  4. Occupation Dynamics and Impacts of Damselfish Territoriality on Recovering Populations of the Threatened Staghorn Coral, Acropora cervicornis.

    PubMed

    Schopmeyer, Stephanie A; Lirman, Diego

    2015-01-01

    Large-scale coral reef restoration is needed to help recover structure and function of degraded coral reef ecosystems and mitigate continued coral declines. In situ coral propagation and reef restoration efforts have scaled up significantly in past decades, particularly for the threatened Caribbean staghorn coral, Acropora cervicornis, but little is known about the role that native competitors and predators, such as farming damselfishes, have on the success of restoration. Steep declines in A. cervicornis abundance may have concentrated the negative impacts of damselfish algal farming on a much lower number of coral prey/colonies, thus creating a significant threat to the persistence and recovery of depleted coral populations. This is the first study to document the prevalence of resident damselfishes and negative effects of algal lawns on A. cervicornis along the Florida Reef Tract (FRT). Impacts of damselfish lawns on A. cervicornis colonies were more prevalent (21.6% of colonies) than those of other sources of mortality (i.e., disease (1.6%), algal/sponge overgrowth (5.6%), and corallivore predation (7.9%)), and damselfish activities caused the highest levels of tissue mortality (34.6%) among all coral stressors evaluated. The probability of damselfish occupation increased as coral colony size and complexity increased and coral growth rates were significantly lower in colonies with damselfish lawns (15.4 vs. 29.6 cm per year). Reduced growth and mortality of existing A. cervicornis populations may have a significant effect on population dynamics by potentially reducing important genetic diversity and the reproductive potential of depleted populations. On a positive note, however, the presence of resident damselfishes decreased predation by other corallivores, such as Coralliophila and Hermodice, and may offset some negative impacts caused by algal farming. While most negative impacts of damselfishes identified in this study affected large individual colonies and

  5. Coral diversity and the severity of disease outbreaks: a cross-regional comparison of Acropora white syndrome in a species-rich region (American Samoa) with a species-poor region (Northwestern Hawaiian Islands).

    USGS Publications Warehouse

    Aeby, G.S.; Bourne, D.G.; Wilson, B.; Work, Thierry M.

    2011-01-01

    The dynamics of the coral disease, Acropora white syndrome (AWS), was directly compared on reefs in the species-poor region of the Northwestern Hawaiian Islands (NWHI) and the species-rich region of American Samoa (AS) with results suggesting that biodiversity, which can affect the abundance of susceptible hosts, is important in influencing the impacts of coral disease outbreaks. The diversity-disease hypothesis predicts that decreased host species diversity should result in increased disease severity of specialist pathogens. We found that AWS was more prevalent and had a higher incidence within the NWHI as compared to AS. Individual Acropora colonies affected by AWS showed high mortality in both regions, but case fatality rate and disease severity was higher in the NWHI. The site within the NWHI had a monospecific stand of A. cytherea; a species that is highly susceptible to AWS. Once AWS entered the site, it spread easily amongst the abundant susceptible hosts. The site within AS contained numerous Acropora species, which differed in their apparent susceptibility to infection and disease severity, which in turn reduced disease spread. Manipulative studies showed AWS was transmissible through direct contact in three Acropora species. These results will help managers predict and respond to disease outbreaks.

  6. A genomewide survey of bHLH transcription factors in the coral Acropora digitifera identifies three novel orthologous families, pearl, amber, and peridot.

    PubMed

    Gyoja, Fuki; Kawashima, Takeshi; Satoh, Nori

    2012-04-01

    Decoding the genome of the coral, Acropora digitifera, enabled us to characterize a nearly full set of 70 basic helix-loop-helix (bHLH) transcription factors in this organism. This number is comparable to 68 bHLH genes in the sea anemone, Nematostella vectensis, and larger than those in most other invertebrate metazoans. The 70 bHLH genes were assigned to 29 orthologous families previously reported. In addition, we identified three novel HLH orthologous families, which we designated pearl, amber, and peridot, increasing the number of orthologous families to 32. Pearl and amber orthologues were found in genomes and expressed sequenced tags (ESTs) of Mollusca and Annelida in addition to Cnidaria. Peridot orthologues were found in genomes and ESTs of Cephalochordata and Hemichordata in addition to Cnidaria. These three genes were likely lost in the clades of Drosophila melanogaster, Caenorhabditis elegans, and Homo sapiens during animal evolution. PMID:22419240

  7. Effect of eight outer continental shelf drilling muds on the calcification rate and free amino acid pool of the coral Acropora cervicornis

    SciTech Connect

    Powell, E.N.; Kendall, J.J. Jr.; Connor, S.J.; Zastrow, C.E.; Bright, T.J.

    1984-09-01

    During most offshore drilling operations, drilling muds are routinely discharged into surrounding waters. Because corals are relatively sensitive to many environmental perturbations and can be adversely affected by offshore drilling operations, the effects of drilling muds on corals have received considerable attention. Because drilling muds are discharged intermittently, only periodic exposures of short duration should impact nearby coral reefs. To fully assess the impact of a drilling mud discharge on corals requires an assessment of the capacity for corals to recover from short-term exposure. The purpose of this study was to assess the relative toxicity of a number of muds that were slated for marine disposal for the coral Acropora cervicornis after a 48-hr recovery period. Calcification rate and free amino acid pool were investigated.

  8. A genomewide survey of bHLH transcription factors in the coral Acropora digitifera identifies three novel orthologous families, pearl, amber, and peridot.

    PubMed

    Gyoja, Fuki; Kawashima, Takeshi; Satoh, Nori

    2012-04-01

    Decoding the genome of the coral, Acropora digitifera, enabled us to characterize a nearly full set of 70 basic helix-loop-helix (bHLH) transcription factors in this organism. This number is comparable to 68 bHLH genes in the sea anemone, Nematostella vectensis, and larger than those in most other invertebrate metazoans. The 70 bHLH genes were assigned to 29 orthologous families previously reported. In addition, we identified three novel HLH orthologous families, which we designated pearl, amber, and peridot, increasing the number of orthologous families to 32. Pearl and amber orthologues were found in genomes and expressed sequenced tags (ESTs) of Mollusca and Annelida in addition to Cnidaria. Peridot orthologues were found in genomes and ESTs of Cephalochordata and Hemichordata in addition to Cnidaria. These three genes were likely lost in the clades of Drosophila melanogaster, Caenorhabditis elegans, and Homo sapiens during animal evolution.

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

    PubMed

    Meyer, Friedrich W; Vogel, Nikolas; Diele, Karen; Kunzmann, Andreas; Uthicke, Sven; Wild, Christian

    2016-01-01

    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 scenarios, as

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

    PubMed

    Meyer, Friedrich W; Vogel, Nikolas; Diele, Karen; Kunzmann, Andreas; Uthicke, Sven; Wild, Christian

    2016-01-01

    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 scenarios, as

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

    PubMed Central

    Meyer, Friedrich W.; Vogel, Nikolas; Diele, Karen; Kunzmann, Andreas; Uthicke, Sven; Wild, Christian

    2016-01-01

    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 scenarios, as

  12. Comparisons of the 1995 and 1998 coral bleaching events on the patch reefs of San Salvador Island, Bahamas.

    PubMed

    McGrath, Thomas A; Smith, Garriet W

    2003-06-01

    Coral patch reefs around San Salvador Island, Bahamas have been monitored with the aid of Earthwatch volunteers three times a year since 1992. During that period two significant mass bleaching events occurred: autumn 1995, and late summer 1998. Elsewhere in 1995, bleaching was caused by higher-than-normal summer sea temperatures; in San Salvador, however, temperatures were normal. In 1998 a prolonged period of higher-than-normal sea temperatures preceded bleaching on San Salvador and worldwide. During the 1995 event, one of the monitored reefs had twice the percentage of coral colonies bleached as the other two. Bleaching was more evenly distributed among the reefs during the 1998 event. In 1995 Agaricia agaricites was significantly more affected than other coral species, with almost 50% of all its colonies showing bleaching. Bleaching was more evenly spread among coral species in 1998, with five species showing bleaching on more than 40% of their colonies. Bleaching began on Millepora as early as August during the 1998 event and progressed to other species through the remainder of the autumn. In 1995 bleaching was not seen until late autumn and appeared to impact all affected species at about the same time. Recovery from the 1995 event was complete: no coral death or damage above normal background levels were seen. In the 1998 event, all Acropora cervicornis on the monitored reefs died and A. palmata was severely damaged. Millepora sp. lost almost half of their live tissue, and Montastraea sp. showed significant tissue damage following this event. Phototransect analysis suggests that more than 20% of total live tissue on affected species died during the 1998 event. A. cervicornis has demonstrated no re-growth from 1998 to 2000 on monitored reefs. Monitoring has suggested significant differences in causes and courses in these two events.

  13. Successive shifts in the microbial community of the surface mucus layer and tissues of the coral Acropora muricata under thermal stress.

    PubMed

    Lee, Sonny T M; Davy, Simon K; Tang, Sen-Lin; Fan, Tung-Yung; Kench, Paul S

    2015-12-01

    The coral mucus may harbor commensal bacteria that inhibit growth of pathogens. Therefore, there is a need to understand the dynamics of bacterial communities between the coral mucus and tissues. Nubbins of Acropora muricata were subjected to increasing water temperatures of 26°C-33°C, to simultaneously explore the bacterial diversity in coral mucus and tissues by 16S rRNA gene amplicon sequencing. Photochemical efficiency of symbiotic dinoflagellates within the corals declined above 31°C. Both the mucus and tissues of healthy A. muricata were dominated by γ-Proteobacteria, but under thermal stress there was a shift towards bacteria from the Verrucomicrobiaceae and α-Proteobacteria. Members of Cyanobacteria, Flavobacteria and Sphingobacteria also become more prominent at higher temperatures. The relative abundance of Vibrio spp. in the coral mucus increased at 29°C, but at 31°C, there was a drop in the relative abundance of Vibrio spp. in the mucus, with a reciprocal increase in the tissues. On the other hand, during bleaching, the relative abundance of Endozoicomonas spp. decreased in the tissues with a reciprocal increase in the mucus. This is the first systematic experiment that shows the potential for a bacterial community shift between the coral surface mucus and tissues in a thermally stressed coral.

  14. Successive shifts in the microbial community of the surface mucus layer and tissues of the coral Acropora muricata under thermal stress.

    PubMed

    Lee, Sonny T M; Davy, Simon K; Tang, Sen-Lin; Fan, Tung-Yung; Kench, Paul S

    2015-12-01

    The coral mucus may harbor commensal bacteria that inhibit growth of pathogens. Therefore, there is a need to understand the dynamics of bacterial communities between the coral mucus and tissues. Nubbins of Acropora muricata were subjected to increasing water temperatures of 26°C-33°C, to simultaneously explore the bacterial diversity in coral mucus and tissues by 16S rRNA gene amplicon sequencing. Photochemical efficiency of symbiotic dinoflagellates within the corals declined above 31°C. Both the mucus and tissues of healthy A. muricata were dominated by γ-Proteobacteria, but under thermal stress there was a shift towards bacteria from the Verrucomicrobiaceae and α-Proteobacteria. Members of Cyanobacteria, Flavobacteria and Sphingobacteria also become more prominent at higher temperatures. The relative abundance of Vibrio spp. in the coral mucus increased at 29°C, but at 31°C, there was a drop in the relative abundance of Vibrio spp. in the mucus, with a reciprocal increase in the tissues. On the other hand, during bleaching, the relative abundance of Endozoicomonas spp. decreased in the tissues with a reciprocal increase in the mucus. This is the first systematic experiment that shows the potential for a bacterial community shift between the coral surface mucus and tissues in a thermally stressed coral. PMID:26564958

  15. Transcriptomic differences between day and night in Acropora millepora provide new insights into metabolite exchange and light-enhanced calcification in corals.

    PubMed

    Bertucci, A; Forêt, S; Ball, E E; Miller, D J

    2015-09-01

    The evolutionary success of reef-building corals is often attributed to their symbiotic relationship with photosynthetic dinoflagellates of the genus Symbiodinium, but metabolic interactions between the partners and the molecular bases of light-enhanced calcification (LEC) are not well understood. Here, the metabolic bases of the interaction between the coral Acropora millepora and its dinoflagellate symbiont were investigated by comparing gene expression levels under light and dark conditions at the whole transcriptome level. Among the 497 differentially expressed genes identified, a suite of genes involved in cholesterol transport was found to be upregulated under light conditions, confirming the significance of this compound in the coral symbiosis. Although ion transporters likely to have roles in calcification were not differentially expressed in this study, expression levels of many genes associated with skeletal organic matrix composition and organization were higher in light conditions. This implies that the rate of organic matrix synthesis is one factor limiting calcification at night. Thus, LEC during the day is likely to be a consequence of increases in both matrix synthesis and the supply of precursor molecules as a result of photosynthetic activity. PMID:26198296

  16. Transcriptomic differences between day and night in Acropora millepora provide new insights into metabolite exchange and light-enhanced calcification in corals.

    PubMed

    Bertucci, A; Forêt, S; Ball, E E; Miller, D J

    2015-09-01

    The evolutionary success of reef-building corals is often attributed to their symbiotic relationship with photosynthetic dinoflagellates of the genus Symbiodinium, but metabolic interactions between the partners and the molecular bases of light-enhanced calcification (LEC) are not well understood. Here, the metabolic bases of the interaction between the coral Acropora millepora and its dinoflagellate symbiont were investigated by comparing gene expression levels under light and dark conditions at the whole transcriptome level. Among the 497 differentially expressed genes identified, a suite of genes involved in cholesterol transport was found to be upregulated under light conditions, confirming the significance of this compound in the coral symbiosis. Although ion transporters likely to have roles in calcification were not differentially expressed in this study, expression levels of many genes associated with skeletal organic matrix composition and organization were higher in light conditions. This implies that the rate of organic matrix synthesis is one factor limiting calcification at night. Thus, LEC during the day is likely to be a consequence of increases in both matrix synthesis and the supply of precursor molecules as a result of photosynthetic activity.

  17. Parameterization of the response of calcification to temperature and pCO2 in the coral Acropora pulchra and the alga Lithophyllum kotschyanum

    NASA Astrophysics Data System (ADS)

    Comeau, S.; Carpenter, R. C.; Lantz, C. A.; Edmunds, P. J.

    2016-09-01

    The response of tropical corals and calcifying algae to ocean acidification (OA) and warming has received much attention in the past decade. However, most studies have evaluated the response of organisms to two or three temperature treatments, which does not allow the functional relationship between calcification and temperature under ambient and future pCO2 to be determined. This study tested the hypothesis that the relationship between calcification and temperature is affected by OA in the coral Acropora pulchra and the calcified alga Lithophyllum kotschyanum. Pieces of each organism were incubated under five (24-30 °C) or six (24-31.5 °C) temperatures crossed with two pCO2 levels (400 and 1000 μatm), and calcification was assessed in trials conducted in the spring and summer. The response of coral calcification to temperature was a positive asymmetric parabola with a maximum at ~28 °C under both pCO2 levels and in both seasons; the effects of pCO2 on calcification were largest at ~28 °C and lowest in both cool and warm temperatures. In contrast, calcification of the alga at both levels of pCO2 was unaffected by temperature in spring, but declined linearly with temperature in summer. This study demonstrates that the calcification response of coral reef organisms to the crossed effect of warming and OA is complex and cannot be fully assessed without using multiple temperature treatments that are ecologically relevant.

  18. Proteomics Links the Redox State to Calcium Signaling During Bleaching of the Scleractinian Coral Acropora microphthalma on Exposure to High Solar Irradiance and Thermal Stress

    PubMed Central

    Weston, Andrew J.; Dunlap, Walter C.; Beltran, Victor H.; Starcevic, Antonio; Hranueli, Daslav; Ward, Malcolm; Long, Paul F.

    2015-01-01

    Shipboard experiments were each performed over a 2 day period to examine the proteomic response of the symbiotic coral Acropora microphthalma exposed to acute conditions of high temperature/low light or high light/low temperature stress. During these treatments, corals had noticeably bleached. The photosynthetic performance of residual algal endosymbionts was severely impaired but showed signs of recovery in both treatments by the end of the second day. Changes in the coral proteome were determined daily and, using recently available annotated genome sequences, the individual contributions of the coral host and algal endosymbionts could be extracted from these data. Quantitative changes in proteins relevant to redox state and calcium metabolism are presented. Notably, expression of common antioxidant proteins was not detected from the coral host but present in the algal endosymbiont proteome. Possible roles for elevated carbonic anhydrase in the coral host are considered: to restore intracellular pH diminished by loss of photosynthetic activity, to indirectly limit intracellular calcium influx linked with enhanced calmodulin expression to impede late-stage symbiont exocytosis, or to enhance inorganic carbon transport to improve the photosynthetic performance of algal symbionts that remain in hospite. Protein effectors of calcium-dependent exocytosis were present in both symbiotic partners. No caspase-family proteins associated with host cell apoptosis, with exception of the autophagy chaperone HSP70, were detected, suggesting that algal loss and photosynthetic dysfunction under these experimental conditions were not due to host-mediated phytosymbiont destruction. Instead, bleaching occurred by symbiont exocytosis and loss of light-harvesting pigments of algae that remain in hospite. These proteomic data are, therefore, consistent with our premise that coral endosymbionts can mediate their own retention or departure from the coral host, which may manifest as

  19. Species Specificity of Bacteria Associated to the Brown Seaweeds Lobophora (Dictyotales, Phaeophyceae) and Their Potential for Induction of Rapid Coral Bleaching in Acropora muricata

    PubMed Central

    Vieira, Christophe; Engelen, Aschwin H.; Guentas, Linda; Aires, Tânia; Houlbreque, Fanny; Gaubert, Julie; Serrão, Ester A.; De Clerck, Olivier; Payri, Claude E.

    2016-01-01

    While reef degradation is occurring worldwide, it is not uncommon to see phase shifts from coral to macroalgal dominated reefs. Numerous studies have addressed the mechanisms by which macroalgae may outcompete corals and a few recent studies highlighted the putative role of bacteria at the interface between macroalgae and corals. Some studies suggest that macroalgae may act as vectors and/or foster proliferation of microorganisms pathogenic for corals. Using a combination of high throughput sequencing, bacterial culturing, and in situ bioassays we question if the adversity of macroalgal-associated bacteria to corals is mediated by specific bacterial taxa. Using Illumina sequencing, we characterized and compared the bacterial community from two Lobophora (Dictyotales, Phaeophyceae) species. The two species presented distinctive bacterial communities. Both species shared approximately half of their OTUs, mainly the most abundant bacteria. Species-specific OTUs belong to Planctomycetes, Proteobacteria, and Bacteroidetes. In total, 16 culturable bacterial strain were isolated and identified from the Lobophora surface, consisting of 10 genera (from nine families, four classes, and three phyla), some of which are not known as, but are related to pathogens involved in coral diseases, and others are naturally associated to corals. When patches of marine agar with 24 h cultures of each of these bacteria were placed in direct contact with the branches of the scleractinian coral Acropora muricata, they caused severe bleaching after 24 h exposure. Results suggest that regardless of taxonomic affinities, increase in density of these bacteria can be adverse to corals. Nevertheless, the microbial community associated to macroalgal surface may not represent a threat to corals, because the specific bacterial screening and control exerted by the alga preventing specific bacterial proliferation. PMID:27047453

  20. Species Specificity of Bacteria Associated to the Brown Seaweeds Lobophora (Dictyotales, Phaeophyceae) and Their Potential for Induction of Rapid Coral Bleaching in Acropora muricata.

    PubMed

    Vieira, Christophe; Engelen, Aschwin H; Guentas, Linda; Aires, Tânia; Houlbreque, Fanny; Gaubert, Julie; Serrão, Ester A; De Clerck, Olivier; Payri, Claude E

    2016-01-01

    While reef degradation is occurring worldwide, it is not uncommon to see phase shifts from coral to macroalgal dominated reefs. Numerous studies have addressed the mechanisms by which macroalgae may outcompete corals and a few recent studies highlighted the putative role of bacteria at the interface between macroalgae and corals. Some studies suggest that macroalgae may act as vectors and/or foster proliferation of microorganisms pathogenic for corals. Using a combination of high throughput sequencing, bacterial culturing, and in situ bioassays we question if the adversity of macroalgal-associated bacteria to corals is mediated by specific bacterial taxa. Using Illumina sequencing, we characterized and compared the bacterial community from two Lobophora (Dictyotales, Phaeophyceae) species. The two species presented distinctive bacterial communities. Both species shared approximately half of their OTUs, mainly the most abundant bacteria. Species-specific OTUs belong to Planctomycetes, Proteobacteria, and Bacteroidetes. In total, 16 culturable bacterial strain were isolated and identified from the Lobophora surface, consisting of 10 genera (from nine families, four classes, and three phyla), some of which are not known as, but are related to pathogens involved in coral diseases, and others are naturally associated to corals. When patches of marine agar with 24 h cultures of each of these bacteria were placed in direct contact with the branches of the scleractinian coral Acropora muricata, they caused severe bleaching after 24 h exposure. Results suggest that regardless of taxonomic affinities, increase in density of these bacteria can be adverse to corals. Nevertheless, the microbial community associated to macroalgal surface may not represent a threat to corals, because the specific bacterial screening and control exerted by the alga preventing specific bacterial proliferation.

  1. Species Specificity of Bacteria Associated to the Brown Seaweeds Lobophora (Dictyotales, Phaeophyceae) and Their Potential for Induction of Rapid Coral Bleaching in Acropora muricata.

    PubMed

    Vieira, Christophe; Engelen, Aschwin H; Guentas, Linda; Aires, Tânia; Houlbreque, Fanny; Gaubert, Julie; Serrão, Ester A; De Clerck, Olivier; Payri, Claude E

    2016-01-01

    While reef degradation is occurring worldwide, it is not uncommon to see phase shifts from coral to macroalgal dominated reefs. Numerous studies have addressed the mechanisms by which macroalgae may outcompete corals and a few recent studies highlighted the putative role of bacteria at the interface between macroalgae and corals. Some studies suggest that macroalgae may act as vectors and/or foster proliferation of microorganisms pathogenic for corals. Using a combination of high throughput sequencing, bacterial culturing, and in situ bioassays we question if the adversity of macroalgal-associated bacteria to corals is mediated by specific bacterial taxa. Using Illumina sequencing, we characterized and compared the bacterial community from two Lobophora (Dictyotales, Phaeophyceae) species. The two species presented distinctive bacterial communities. Both species shared approximately half of their OTUs, mainly the most abundant bacteria. Species-specific OTUs belong to Planctomycetes, Proteobacteria, and Bacteroidetes. In total, 16 culturable bacterial strain were isolated and identified from the Lobophora surface, consisting of 10 genera (from nine families, four classes, and three phyla), some of which are not known as, but are related to pathogens involved in coral diseases, and others are naturally associated to corals. When patches of marine agar with 24 h cultures of each of these bacteria were placed in direct contact with the branches of the scleractinian coral Acropora muricata, they caused severe bleaching after 24 h exposure. Results suggest that regardless of taxonomic affinities, increase in density of these bacteria can be adverse to corals. Nevertheless, the microbial community associated to macroalgal surface may not represent a threat to corals, because the specific bacterial screening and control exerted by the alga preventing specific bacterial proliferation. PMID:27047453

  2. KEGG orthology-based annotation of the predicted proteome of Acropora digitifera: ZoophyteBase - an open access and searchable database of a coral genome

    PubMed Central

    2013-01-01

    Background Contemporary coral reef research has firmly established that a genomic approach is urgently needed to better understand the effects of anthropogenic environmental stress and global climate change on coral holobiont interactions. Here we present KEGG orthology-based annotation of the complete genome sequence of the scleractinian coral Acropora digitifera and provide the first comprehensive view of the genome of a reef-building coral by applying advanced bioinformatics. Description Sequences from the KEGG database of protein function were used to construct hidden Markov models. These models were used to search the predicted proteome of A. digitifera to establish complete genomic annotation. The annotated dataset is published in ZoophyteBase, an open access format with different options for searching the data. A particularly useful feature is the ability to use a Google-like search engine that links query words to protein attributes. We present features of the annotation that underpin the molecular structure of key processes of coral physiology that include (1) regulatory proteins of symbiosis, (2) planula and early developmental proteins, (3) neural messengers, receptors and sensory proteins, (4) calcification and Ca2+-signalling proteins, (5) plant-derived proteins, (6) proteins of nitrogen metabolism, (7) DNA repair proteins, (8) stress response proteins, (9) antioxidant and redox-protective proteins, (10) proteins of cellular apoptosis, (11) microbial symbioses and pathogenicity proteins, (12) proteins of viral pathogenicity, (13) toxins and venom, (14) proteins of the chemical defensome and (15) coral epigenetics. Conclusions We advocate that providing annotation in an open-access searchable database available to the public domain will give an unprecedented foundation to interrogate the fundamental molecular structure and interactions of coral symbiosis and allow critical questions to be addressed at the genomic level based on combined aspects of

  3. Proteomics links the redox state to calcium signaling during bleaching of the scleractinian coral Acropora microphthalma on exposure to high solar irradiance and thermal stress.

    PubMed

    Weston, Andrew J; Dunlap, Walter C; Beltran, Victor H; Starcevic, Antonio; Hranueli, Daslav; Ward, Malcolm; Long, Paul F

    2015-03-01

    Shipboard experiments were each performed over a 2 day period to examine the proteomic response of the symbiotic coral Acropora microphthalma exposed to acute conditions of high temperature/low light or high light/low temperature stress. During these treatments, corals had noticeably bleached. The photosynthetic performance of residual algal endosymbionts was severely impaired but showed signs of recovery in both treatments by the end of the second day. Changes in the coral proteome were determined daily and, using recently available annotated genome sequences, the individual contributions of the coral host and algal endosymbionts could be extracted from these data. Quantitative changes in proteins relevant to redox state and calcium metabolism are presented. Notably, expression of common antioxidant proteins was not detected from the coral host but present in the algal endosymbiont proteome. Possible roles for elevated carbonic anhydrase in the coral host are considered: to restore intracellular pH diminished by loss of photosynthetic activity, to indirectly limit intracellular calcium influx linked with enhanced calmodulin expression to impede late-stage symbiont exocytosis, or to enhance inorganic carbon transport to improve the photosynthetic performance of algal symbionts that remain in hospite. Protein effectors of calcium-dependent exocytosis were present in both symbiotic partners. No caspase-family proteins associated with host cell apoptosis, with exception of the autophagy chaperone HSP70, were detected, suggesting that algal loss and photosynthetic dysfunction under these experimental conditions were not due to host-mediated phytosymbiont destruction. Instead, bleaching occurred by symbiont exocytosis and loss of light-harvesting pigments of algae that remain in hospite. These proteomic data are, therefore, consistent with our premise that coral endosymbionts can mediate their own retention or departure from the coral host, which may manifest as

  4. Historical and contemporary factors shape the population genetic structure of the broadcast spawning coral, Acropora millepora, on the Great Barrier Reef.

    PubMed

    Van Oppen, Madeleine J H; Peplow, Lesa M; Kininmonth, Stuart; Berkelmans, Ray

    2011-12-01

    Effective management of reef corals requires knowledge of the extent to which populations are open or closed and the scales over which genetic exchange occurs, information which is commonly derived from population genetic data. Such data are sparse for Great Barrier Reef (GBR) corals and other organisms, with the studies that are available being mostly based on a small number of sampling locations spanning only part of the GBR. Using 11 microsatellite loci, we genotyped 947 colonies of the reef-building coral Acropora millepora from 20 sites spanning almost the full length of the GBR (∼12° of latitude and ∼1550 km). The results show a major divide between the southernmost central to southern offshore populations and all other sampled populations. We interpret this divide as a signature of allopatric divergence in northern and southern refugia during the Pleistocene glaciations, from which the GBR was subsequently recolonized. Superimposed on this pattern is a cross-shelf genetic division, as well as a separation of inshore populations south of the Cape Clifton Front at ∼21.5-22°S. Most inshore populations north of this, as well as mid-shelf populations in the northern and far northern GBR, are open, exchanging recruits frequently. In contrast, inshore populations south of the Cape Clifton Front and offshore populations in the central and southern GBR are largely self-seeding, at least within the spatial resolution that was achieved given our sampling intensity. Populations that have been impacted by recent disturbance events causing extensive coral mortality show no evidence of reduced genetic diversity.

  5. Response of Acropora digitifera to ocean acidification: constraints from δ11B, Sr, Mg, and Ba compositions of aragonitic skeletons cultured under variable seawater pH

    NASA Astrophysics Data System (ADS)

    Tanaka, Kentaro; Holcomb, Michael; Takahashi, Asami; Kurihara, Haruko; Asami, Ryuji; Shinjo, Ryuichi; Sowa, Kohki; Rankenburg, Kai; Watanabe, Tsuyoshi; McCulloch, Malcolm

    2015-12-01

    The response of Acropora digitifera to ocean acidification is determined using geochemical proxy measurements of the skeletal composition of A. digitifera cultured under a range of pH levels. We show that the chemical composition (δ11B, Sr/Ca, Mg/Ca, and Ba/Ca) of the coral skeletons can provide quantitative constraints on the effects of seawater pH on the pH in the calcification fluid (pHCF) and the mechanisms controlling the incorporation of trace elements into coral aragonite. With the decline of seawater pH, the skeletal δ11B value decreased, while the Sr/Ca ratio showed an increasing trend. The relationship between Mg/Ca and Ba/Ca versus seawater pH was not significant. Inter-colony variation of δ11B was insignificant, although inter-colony variation was observed for Ba/Ca. The decreasing trend of pHCF calculated from δ11B was from ~8.5, 8.4, and 8.3 for seawater pH of ~8.1, 7.8, and 7.4, respectively. Model calculations based on Sr/Ca and pHCF suggest that upregulation of pHCF occurs via exchange of H+ with Ca2+ with kinetic effects (Rayleigh fractionation), reducing Sr/Ca relative to inorganic deposition of aragonite from seawater. We show that it is possible to constrain the overall carbonate chemistry of the calcifying fluid with estimates of the carbonate saturation of the calcifying fluid ( Ω CF) being derived from skeletal Sr/Ca and pHCF (from δ11B). These estimates suggest that the aragonite saturation state of the calcifying fluid Ω CF is elevated by a factor of 5-10 relative to ambient seawater under all treatment conditions.

  6. Expression of calcification and metabolism-related genes in response to elevated pCO2 and temperature in the reef-building coral Acropora millepora.

    PubMed

    Rocker, Melissa M; Noonan, Sam; Humphrey, Craig; Moya, Aurelie; Willis, Bette L; Bay, Line K

    2015-12-01

    Declining health of scleractinian corals in response to deteriorating environmental conditions is widely acknowledged, however links between physiological and functional genomic responses of corals are less well understood. Here we explore growth and the expression of 20 target genes with putative roles in metabolism and calcification in the branching coral, Acropora millepora, in two separate experiments: 1) elevated pCO2 (464, 822, 1187 and 1638 μatm) and ambient temperature (27°C), and 2) elevated pCO2 (490 and 822 μatm) and temperature (28 and 31 °C). After 14 days of exposure to elevated pCO2 and ambient temperatures, no evidence of differential expression of either calcification or metabolism genes was detected between control and elevated pCO2 treatments. After 37 days of exposure to control and elevated pCO2, Ubiquinol-Cytochrome-C Reductase Subunit 2 gene (QCR2; a gene involved in complex III of the electron chain transport within the mitochondria and critical for generation of ATP) was significantly down-regulated in the elevated pCO2 treatment in both ambient and elevated temperature treatments. Overall, the general absence of a strong response to elevated pCO2 and temperature by the other 19 targeted calcification and metabolism genes suggests that corals may not be affected by these stressors on longer time scales (37 days). These results also highlight the potential for QCR2 to act as a biomarker of coral genomic responses to changing environments.

  7. Estimate of calcification responses to thermal and freshening stresses based on culture experiments with symbiotic and aposymbiotic primary polyps of a coral, Acropora digitifera

    NASA Astrophysics Data System (ADS)

    Inoue, Mayuri; Shinmen, Kotaro; Kawahata, Hodaka; Nakamura, Takashi; Tanaka, Yasuaki; Kato, Aki; Shinzato, Chuya; Iguchi, Akira; Kan, Hironobu; Suzuki, Atsushi; Sakai, Kazuhiko

    2012-07-01

    Although coral calcification is directly related to coral health, few studies have examined the responses of coral calcification to environmental stresses, with the exception of ocean acidification. In this study, we experimentally exposed aposymbiotic (lacking symbionts) and symbiotic primary polyps of the scleractinian coral Acropora digitifera to several seawater temperatures (27, 29, 31, and 33 °C) and salinities (26, 28, 30, 32, and 34) to investigate the effects of thermal and freshening stresses on coral calcification from the standpoint of coral-algal symbiosis. Calcification rates were higher for symbiotic versus aposymbiotic polyps in both sets of experiments, except for those reared at 31 °C and 33 °C. Calcification responses of symbiotic polyps were a non-linear function of temperature, and the threshold temperature affecting skeletal growth and bleaching was between 29 °C and 31 °C. Calcification rates of aposymbiotic polyps were also a non-linear function of temperature, with a maximum polyp weight at 31 °C, suggesting that thermal stress also did some damage to the coral host itself. In contrast, skeletal growth of both aposymbiotic and symbiotic polyps decreased linearly with increased salinity. Observations of the microstructure of polyp samples revealed a clearly cyclic feature of skeletal surfaces that was likely related to organo-mineral deposition of calcium carbonate even under lowered-salinity conditions. However, neither type of polyp reared at 33 °C evidenced this characteristic, suggesting that thermal stress had compromised the normal calcification process, which involves secretion of an organic matrix by the coral host. Our results suggest that the effects of future global warming will include a reduction in coral calcification itself and the collapse of coral-algal symbiosis, at least at the primary polyp stage. The present experiments showed that thermal stress would affect the host's physiological functionality, whereas

  8. SYMBIODINIUM ISOLATES FROM STONY CORAL: ISOLATION, GROWTH CHARACTERISTICS AND EFFECTS OF UV IRRADIATION

    EPA Science Inventory

    Symbiodinium spp. Isolates from Stony Coral: Isolation, Growth Characteristics and Effects of UV Irradiation (Abstract). J. Phycol. 37(3):42-43.

    Symbiodinium species were isolated from Montipora capitata, Acropora palmata and two field samples of Porites porites. Cultures ...

  9. Ocean acidification impact on growth and the pH dependence of trace elements in skeleton of juvenile corals (Acropora digitifera)

    NASA Astrophysics Data System (ADS)

    Inoue, M.; Suwa, R.; Iguchi, A.; Suzuki, A.; Sakai, K.; Kawahata, H.

    2010-12-01

    The impact of ocean acidification caused by the increasing global concentration of atmospheric CO2 has been studied in marine calcifiers, including hermatypic corals, in which calcification is expected to decrease significantly. However, the effect of elevated pCO2 on the early developmental stage of the coral life cycle has been little studied, even though corals at this stage seem to be susceptible to stresses including ocean acidification. In this study, we reared polyps of Acropora digitifera, one of the dominant species around the Ryukyu Islands, Japan, in seawater of various pH (6.55, 7.31, 7.64, 7.77, 8.03), controlled by CO2 bubbling. We measured the dry weight of the polyp skeletons after the 40 days experiment to investigate the relationship between the aragonite saturation state and polyp growth. In addition, we measured the Mg/Ca, Sr/Ca, Ba/Ca, and U/Ca ratios of their skeletons to estimate the pH dependence of these ratios. Although skeletons of polyps reared at pH 6.55 dissolved during the experiment after settlement, the other skeletal weight of coral polyps increased with the aragonite saturation state. Then, skeletal weight apparently reached a saturation plateau above pH 7.77, a finding in agreement with previous results for adult corals. Ba/Ca and U/Ca were significantly related to pH, whereas Sr/Ca showed a moderate positive correlation with pH. On the other hand, there was no clear relationship between Mg/Ca and pH. Although both the Ba/Ca and U/Ca ratios showed a strong dependency on pH, coral Ba/Ca is reported to be affected by multiple factors such as terrestrial runoff and upwelling. But, U/Ca ratios have been reported a relatively simple dependency on temperature. Therefore, coral U/Ca may have a potential for pH proxy.

  10. Geologic history of Grecian Rocks, Key Largo Coral Reef Marine Sanctuary.

    USGS Publications Warehouse

    Shinn, E.A.

    1980-01-01

    Two transects were drilled across the major ecologic zones of the c. 750 by 200 m reef, whose accumulation was controlled by a local Pleistocene topographic feature. The Reef is composed of 5 major ecologic zones: 1) a deep seaward rubble zone, 6-8 m depth; 2) a poorly developed spur and groove zone composed of massive head corals and Millepora (4-6 m water depth); 3) a characteristic high-energy oriented Acropora palmata zone extending from the surface down to 4 m; 4) a distinct broad reef flat composed of in situ A. palmata and coral rubble, followed by 5) a narrow low- energy back-reef zone of unoriented A. palmata, thickets of A. cervicornis, and various massive head corals in water 0-3 m deep. An extensive grass-covered carbonate sand flat 3-4 m deep extends in a landward direction from zone 5. - from Author

  11. Hybridization and the evolution of reef coral diversity.

    PubMed

    Vollmer, Steven V; Palumbi, Stephen R

    2002-06-14

    Hundreds of coral species coexist sympatrically on reefs, reproducing in mass-spawning events where hybridization appears common. In the Caribbean, DNA sequence data from all three sympatric Acropora corals show that mass spawning does not erode species barriers. Species A. cervicornis and A. palmata are distinct at two nuclear loci or share ancestral alleles. Morphotypes historically given the name Acropora prolifera are entirely F(1) hybrids of these two species, showing morphologies that depend on which species provides the egg for hybridization. Although selection limits the evolutionary potential of hybrids, F(1) individuals can reproduce asexually and form long-lived, potentially immortal hybrids with unique morphologies.

  12. Patterns of sexual recruitment of acroporid coral populations on the west fore reef at Discovery Bay, Jamaica.

    PubMed

    Quinn, Norman J; Kojis, Barbara L

    2005-05-01

    Coral recruitment was examined on terracotta tiles deployed for four six-month periods between March 2001 and April 2003 on the West Fore Reef at Discovery Bay, Jamaica. During each sampling period, four tiles were deployed on each of two arrays at six depths ranging from 3 m to 33 m. Only three Acropora spat recruited to the tiles over the sampling period. The Acropora spat recruited during only one of the four six-month sampling periods and at only one depth, 3m. That represents a density of 8 spat m(-2) at 3 m depth for one six-month sampling period. Acropora recruitment represented <1 % of the total spat recruiting to the tiles deployed at 3 m during the four sampling periods. Density of acroporids on the West Fore Reef is low. Only one Acropora colony (an A. palmata) was recorded during Point-Quarter surveys of coral cover and density at depths of 3 m, 9 m, 14 m and 19 m. Considering the paucity of acroporid colonies and the infrequent settlement of acroporid spat on the West Fore Reef, it is unlikely that the historic abundance of A. palmata and A. cervicornis will return soon.

  13. Revised paleoenvironmental analysis of the Holocene portion of the Barbados sea-level record: Cobbler's Reef revisited

    NASA Astrophysics Data System (ADS)

    Toscano, Marguerite A.

    2016-06-01

    Sample elevations corrected for tectonic uplift and assessed relative to local modeled sea levels provide a new perspective on paleoenvironmental history at Cobbler's Reef, Barbados. Previously, 14C-dated surface samples of fragmented Acropora palmata plotted above paleo sea level based on their present (uplifted) elevations, suggesting supratidal rubble deposited during a period of extreme storms (4500-3000 cal BP), precipitating reef demise. At several sites, however, A. palmata persisted, existing until ~370 cal BP. Uplift-corrected A. palmata sample elevations lie below the western Atlantic sea-level curve, and ~2 m below ICE-6G-modeled paleo sea level, under slow rates of sea-level rise, negating the possibility that Cobbler's Reef is a supratidal storm ridge. Most sites show limited age ranges from corals likely damaged/killed on the reef crest, not the mixed ages of rubble ridges, strongly suggesting the reef framework died off in stages over 6500 yr. Reef crest death assemblages invoke multiple paleohistoric causes, from ubiquitous hurricanes to anthropogenic impacts. Comparison of death assemblage ages to dated regional paleotempestological sequences, proxy-based paleotemperatures, recorded hurricanes, tsunamis, European settlement, deforestation, and resulting turbidity, reveals many possible factors inimical to the survival of A. palmata along Cobbler's Reef.

  14. Topographic control and accumulation rate of some Holocene coral reefs: south Florida and Dry Tortugas

    USGS Publications Warehouse

    Shinn, E.A.; Hudson, J.H.; Halley, R.B.; Lidz, B.H.; Taylor, D.L.

    1977-01-01

    Core drilling and examination of underwater excavation on 6 reef sites in south Florida and Dry Tortugas revealed that underlying topography is the major factor controlling reef morphology. Carbon-14 dating on coral recovered from cores enables calculation of accumulation rates. Accumulation rates were found to range from 0.38 m/1000 years in thin Holocene reefs to as much as 4.85 m/1000 years in thicker buildups. Cementation and alteration of corals were found to be more pronounced in areas of low buildup rates than in areas of rapid accumulation rates. Acropora palmata, generally considered the major reef builder in Florida, was found to be absent in most reefs drilled. At Dry Tortugas, the more than 13-meter thick Holocene reef did not contain A. palmata. The principal reef builders in this outer reef are the same as those which built the Pleistocene Key Largo formation, long considered to be fossilized patch reef complex.

  15. Lithifying Microbes Associated to Coral Rubbles

    NASA Astrophysics Data System (ADS)

    Beltran, Y.

    2015-12-01

    Microbial communities taking part in calcium carbonate lithification processes are particularly relevant to coral reef formation in as much as this lithification allows the stabilization of secondary reef structure. This second framework promotes long-term permanence of the reef, favoring the establishment of macro-reef builders, including corals. The reef-bacterial crusts formed by microbial communities are composed of magnesium calcite. Although prokaryotes are not proper calcifiers, carbonate precipitation can be induced by their metabolic activity and EPS production. Coral reefs are rapidly declining due to several variables associated to environmental change. Specifically in the Caribbean, stony coral Acropora palmata have suffered damage due to diseases, bleaching and storms. Some reports show that in highly disturbed areas wide ridges of reef rubbles are formed by biological and physical lithification. In this study we explore microbial diversity associated to lithified rubbles left after the great decline of reef-building A. palmata.

  16. Storm-generated coral fragments - A viable source of transplants for reef rehabilitation

    USGS Publications Warehouse

    Garrison, V.; Ward, G.

    2008-01-01

    Coral reefs throughout the world have been damaged by storms, diseases, coral predators, temperature anomalies, and human activities. During the past three decades, recovery has been limited and patchy. Although a damaged coral reef cannot be restored to its original condition, interest in reef restoration is increasing. In a pilot project in the Caribbean (US Virgin Islands), storm-produced fragments of Acropora palmata, A. cervicornis, and Porites porites were collected from donor reefs and transplanted to nearby degraded reefs. Sixty coral fragments were attached to dead-coral substrate (usually A. palmata skeletons), at similar depths from which they had been collected (1-3.5 m), using nylon cable ties. Seventy-five intact colonies were designated as controls. Study colonies were assessed at 6-month intervals for 2 years (1999-2001) and annually thereafter (through 2004). One-fourth of the 135 colonies and fragments monitored were alive at the conclusion of the 5-year study. Survival of control and transplanted A. cervicornis and P. porites was very low (median survival 2.4 and 1.8 years, respectively), with no significant differences between transplant and control colonies. Site and depth did not contribute significantly to A. palmata colony survival, but colony size and transplant/control status did. Probability of survival increased with colony size. Median survival for A. palmata was 1.3 years for transplant and 4.3 years for natural colonies when not controlled for size. A. palmata was the only viable candidate for reef rehabilitation. Storm swells were the primary cause of mortality.

  17. Removal of corallivorous snails as a proactive tool for the conservation of acroporid corals

    PubMed Central

    Miller, Margaret W.; Bright, Allan J.; Cameron, Caitlin M.

    2014-01-01

    Corallivorous snail feeding is a common source of tissue loss for the threatened coral, Acropora palmata, accounting for roughly one-quarter of tissue loss in monitored study plots over seven years. In contrast with larger threats such as bleaching, disease, or storms, corallivory by Coralliophila abbreviata is one of the few direct sources of partial mortality that may be locally managed. We conducted a field experiment to explore the effectiveness and feasibility of snail removal. Long-term monitoring plots on six reefs in the upper Florida Keys were assigned to one of three removal treatments: (1) removal from A. palmata only, (2) removal from all host coral species, or (3) no-removal controls. During the initial removal in June 2011, 436 snails were removed from twelve 150 m2 plots. Snails were removed three additional times during a seven month “removal phase”, then counted at five surveys over the next 19 months to track recolonization. At the conclusion, snails were collected, measured and sexed. Before-After-Control-Impact analysis revealed that both snail abundance and feeding scar prevalence were reduced in removal treatments compared to the control, but there was no difference between removal treatments. Recolonization by snails to baseline abundance is estimated to be 3.7 years and did not differ between removal treatments. Recolonization rate was significantly correlated with baseline snail abundance. Maximum snail size decreased from 47.0 mm to 34.6 mm in the removal treatments. The effort required to remove snails from A. palmata was 30 diver minutes per 150 m2 plot, compared with 51 min to remove snails from all host corals. Since there was no additional benefit observed with removing snails from all host species, removals can be more efficiently focused on only A. palmata colonies and in areas where C. abbreviata abundance is high, to effectively conserve A. palmata in targeted areas. PMID:25469321

  18. Enhanced susceptibility to predation in corals of compromised condition

    PubMed Central

    Cameron, Caitlin M.; Miller, Margaret W.

    2015-01-01

    The marine gastropod, Coralliophila abbreviata, is an obligate corallivore that causes substantial mortality in Caribbean Acropora spp. Considering the imperiled status of Acropora cervicornis and A. palmata, a better understanding of ecological interactions resulting in tissue loss may enable more effective conservation strategies. We examined differences in susceptibility of A. cervicornis to C. abbreviata predation based on coral tissue condition. Coral tissue condition was a strong determinant of snail prey choice, with snails preferring A. cervicornis fragments that were diseased or mechanically damaged over healthy fragments. In addition, snails always chose fragments undergoing active predation by another snail, while showing no preference for a non-feeding snail when compared with an undisturbed prey fragment. These results indicate that the condition of A. cervicornis prey influenced foraging behavior of C. abbreviata, creating a potential feedback that may exacerbate damage from predation in coral populations compromised by other types of disturbance. PMID:26734500

  19. FACTORS AFFECTING SUSCEPTIBILITY OF THE CORAL MONTASTRAEA FAVEOLATE TO BLACK-BAND DISEASE

    EPA Science Inventory

    Black-band disease affects many species of tropical reef-building corals, but it is unclear what factors contribute to the disease-susceptibility of individual corals or how the disease is transmitted between colonies. Studies have suggested that the ability of black-band disease...

  20. Contemporary white-band disease in Caribbean corals driven by climate change

    NASA Astrophysics Data System (ADS)

    Randall, C. J.; van Woesik, R.

    2015-04-01

    Over the past 40 years, two of the dominant reef-building corals in the Caribbean, Acropora palmata and Acropora cervicornis, have experienced unprecedented declines. That loss has been largely attributed to a syndrome commonly referred to as white-band disease. Climate change-driven increases in sea surface temperature (SST) have been linked to several coral diseases, yet, despite decades of research, the attribution of white-band disease to climate change remains unknown. Here we hindcasted the potential relationship between recent ocean warming and outbreaks of white-band disease on acroporid corals. We quantified eight SST metrics, including rates of change in SST and contemporary thermal anomalies, and compared them with records of white-band disease on A. palmata and A. cervicornis from 473 sites across the Caribbean, surveyed from 1997 to 2004. The results of our models suggest that decades-long climate-driven changes in SST, increases in thermal minima, and the breach of thermal maxima have all played significant roles in the spread of white-band disease. We conclude that white-band disease has been strongly coupled with thermal stresses associated with climate change, which has contributed to the regional decline of these once-dominant reef-building corals.

  1. Preserving and Using Germplasm and Dissociated Embryonic Cells for Conserving Caribbean and Pacific Coral

    PubMed Central

    Hagedorn, Mary; Carter, Virginia; Martorana, Kelly; Paresa, Malia K.; Acker, Jason; Baums, Iliana B.; Borneman, Eric; Brittsan, Michael; Byers, Michael; Henley, Michael; Laterveer, Michael; Leong, Jo-Ann; McCarthy, Megan; Meyers, Stuart; Nelson, Brian D.; Petersen, Dirk; Tiersch, Terrence; Uribe, Rafael Cuevas; Woods, Erik; Wildt, David

    2012-01-01

    Coral reefs are experiencing unprecedented degradation due to human activities, and protecting specific reef habitats may not stop this decline, because the most serious threats are global (i.e., climate change), not local. However, ex situ preservation practices can provide safeguards for coral reef conservation. Specifically, modern advances in cryobiology and genome banking could secure existing species and genetic diversity until genotypes can be introduced into rehabilitated habitats. We assessed the feasibility of recovering viable sperm and embryonic cells post-thaw from two coral species, Acropora palmata and Fungia scutaria that have diffferent evolutionary histories, ecological niches and reproductive strategies. In vitro fertilization (IVF) of conspecific eggs using fresh (control) spermatozoa revealed high levels of fertilization (>90% in A. palmata; >84% in F. scutaria; P>0.05) that were unaffected by tested sperm concentrations. A solution of 10% dimethyl sulfoxide (DMSO) at cooling rates of 20 to 30°C/min most successfully cryopreserved both A. palmata and F. scutaria spermatozoa and allowed producing developing larvae in vitro. IVF success under these conditions was 65% in A. palmata and 53% in F. scutaria on particular nights; however, on subsequent nights, the same process resulted in little or no IVF success. Thus, the window for optimal freezing of high quality spermatozoa was short (∼5 h for one night each spawning cycle). Additionally, cryopreserved F. scutaria embryonic cells had∼50% post-thaw viability as measured by intact membranes. Thus, despite some differences between species, coral spermatozoa and embryonic cells are viable after low temperature (−196°C) storage, preservation and thawing. Based on these results, we have begun systematically banking coral spermatozoa and embryonic cells on a large-scale as a support approach for preserving existing bio- and genetic diversity found in reef systems. PMID:22413020

  2. Preserving and using germplasm and dissociated embryonic cells for conserving Caribbean and Pacific coral.

    PubMed

    Hagedorn, Mary; Carter, Virginia; Martorana, Kelly; Paresa, Malia K; Acker, Jason; Baums, Iliana B; Borneman, Eric; Brittsan, Michael; Byers, Michael; Henley, Michael; Laterveer, Michael; Leong, Jo-Ann; McCarthy, Megan; Meyers, Stuart; Nelson, Brian D; Petersen, Dirk; Tiersch, Terrence; Uribe, Rafael Cuevas; Woods, Erik; Wildt, David

    2012-01-01

    Coral reefs are experiencing unprecedented degradation due to human activities, and protecting specific reef habitats may not stop this decline, because the most serious threats are global (i.e., climate change), not local. However, ex situ preservation practices can provide safeguards for coral reef conservation. Specifically, modern advances in cryobiology and genome banking could secure existing species and genetic diversity until genotypes can be introduced into rehabilitated habitats. We assessed the feasibility of recovering viable sperm and embryonic cells post-thaw from two coral species, Acropora palmata and Fungia scutaria that have diffferent evolutionary histories, ecological niches and reproductive strategies. In vitro fertilization (IVF) of conspecific eggs using fresh (control) spermatozoa revealed high levels of fertilization (>90% in A. palmata; >84% in F. scutaria; P>0.05) that were unaffected by tested sperm concentrations. A solution of 10% dimethyl sulfoxide (DMSO) at cooling rates of 20 to 30°C/min most successfully cryopreserved both A. palmata and F. scutaria spermatozoa and allowed producing developing larvae in vitro. IVF success under these conditions was 65% in A. palmata and 53% in F. scutaria on particular nights; however, on subsequent nights, the same process resulted in little or no IVF success. Thus, the window for optimal freezing of high quality spermatozoa was short (∼5 h for one night each spawning cycle). Additionally, cryopreserved F. scutaria embryonic cells had∼50% post-thaw viability as measured by intact membranes. Thus, despite some differences between species, coral spermatozoa and embryonic cells are viable after low temperature (-196°C) storage, preservation and thawing. Based on these results, we have begun systematically banking coral spermatozoa and embryonic cells on a large-scale as a support approach for preserving existing bio- and genetic diversity found in reef systems. PMID:22413020

  3. Transplantation of storm-generated coral fragments to enhance Caribbean coral reefs: A successful method but not a solution

    USGS Publications Warehouse

    Garrison, V.H.; Ward, G.

    2012-01-01

    In response to dramatic losses of reef-building corals and ongoing lack of recovery, a small-scale coral transplant project was initiated in the Caribbean (U.S. Virgin Islands) in 1999 and was followed for 12 years. The primary objectives were to (1) identify a source of coral colonies for transplantation that would not result in damage to reefs, (2) test the feasibility of transplanting storm-generated coral fragments, and (3) develop a simple, inexpensive method for transplanting fragments that could be conducted by the local community. The ultimate goal was to enhance abundance of threatened reef-building species on local reefs. Storm-produced coral fragments of two threatened reef-building species [Acropora palmata and A. cervicornis (Acroporidae)] and another fast-growing species [Porites porites (Poritidae)] were collected from environments hostile to coral fragment survival and transplanted to degraded reefs. Inert nylon cable ties were used to attach transplanted coral fragments to dead coral substrate. Survival of 75 reference colonies and 60 transplants was assessed over 12 years. Only 9% of colonies were alive after 12 years: no A. cervicornis; 3% of A. palmata transplants and 18% of reference colonies; and 13% of P. porites transplants and 7% of reference colonies. Mortality rates for all species were high and were similar for transplant and reference colonies. Physical dislodgement resulted in the loss of 56% of colonies, whereas 35% died in place. Only A. palmata showed a difference between transplant and reference colony survival and that was in the first year only. Location was a factor in survival only for A. palmata reference colonies and after year 10. Even though the tested methods and concepts were proven effective in the field over the 12-year study, they do not present a solution. No coral conservation strategy will be effective until underlying intrinsic and/or extrinsic factors driving high mortality rates are understood and mitigated or

  4. Natural Disease Resistance in Threatened Staghorn Corals

    PubMed Central

    Vollmer, Steven V.; Kline, David I.

    2008-01-01

    Disease epidemics have caused extensive damage to tropical coral reefs and to the reef-building corals themselves, yet nothing is known about the abilities of the coral host to resist disease infection. Understanding the potential for natural disease resistance in corals is critically important, especially in the Caribbean where the two ecologically dominant shallow-water corals, Acropora cervicornis and A. palmata, have suffered an unprecedented mass die-off due to White Band Disease (WBD), and are now listed as threatened under the US Threatened Species Act and as critically endangered under the IUCN Red List criteria. Here we examine the potential for natural resistance to WBD in the staghorn coral Acropora cervicornis by combining microsatellite genotype information with in situ transmission assays and field monitoring of WBD on tagged genotypes. We show that six percent of staghorn coral genotypes (3 out of 49) are resistant to WBD. This natural resistance to WBD in staghorn corals represents the first evidence of host disease resistance in scleractinian corals and demonstrates that staghorn corals have an innate ability to resist WBD infection. These resistant staghorn coral genotypes may explain why pockets of Acropora have been able to survive the WBD epidemic. Understanding disease resistance in these corals may be the critical link to restoring populations of these once dominant corals throughout their range. PMID:19005565

  5. Natural disease resistance in threatened staghorn corals.

    PubMed

    Vollmer, Steven V; Kline, David I

    2008-01-01

    Disease epidemics have caused extensive damage to tropical coral reefs and to the reef-building corals themselves, yet nothing is known about the abilities of the coral host to resist disease infection. Understanding the potential for natural disease resistance in corals is critically important, especially in the Caribbean where the two ecologically dominant shallow-water corals, Acropora cervicornis and A. palmata, have suffered an unprecedented mass die-off due to White Band Disease (WBD), and are now listed as threatened under the US Threatened Species Act and as critically endangered under the IUCN Red List criteria. Here we examine the potential for natural resistance to WBD in the staghorn coral Acropora cervicornis by combining microsatellite genotype information with in situ transmission assays and field monitoring of WBD on tagged genotypes. We show that six percent of staghorn coral genotypes (3 out of 49) are resistant to WBD. This natural resistance to WBD in staghorn corals represents the first evidence of host disease resistance in scleractinian corals and demonstrates that staghorn corals have an innate ability to resist WBD infection. These resistant staghorn coral genotypes may explain why pockets of Acropora have been able to survive the WBD epidemic. Understanding disease resistance in these corals may be the critical link to restoring populations of these once dominant corals throughout their range.

  6. Stable isotopic records of bleaching and endolithic algae blooms in the skeleton of the boulder forming coral Montastraea faveolata

    NASA Astrophysics Data System (ADS)

    Hartmann, A. C.; Carilli, J. E.; Norris, R. D.; Charles, C. D.; Deheyn, D. D.

    2010-12-01

    Within boulder forming corals, fixation of dissolved inorganic carbon is performed by symbiotic dinoflagellates within the coral tissue and, to a lesser extent, endolithic algae within the coral skeleton. Endolithic algae produce distinctive green bands in the coral skeleton, and their origin may be related to periods of coral bleaching due to complete loss of dinoflagellate symbionts or “paling” in which symbiont populations are patchily reduced in coral tissue. Stable carbon isotopes were analyzed in coral skeletons across a known bleaching event and 12 blooms of endolithic algae to determine whether either of these types of changes in photosynthesis had a clear isotopic signature. Stable carbon isotopes tended to be enriched in the coral skeleton during the initiation of endolith blooms, consistent with enhanced photosynthesis by endoliths. In contrast, there were no consistent δ13C patterns directly associated with bleaching, suggesting that there is no unique isotopic signature of bleaching. On the other hand, isotopic values after bleaching were lighter 92% of the time when compared to the bleaching interval. This marked drop in skeletal δ13C may reflect increased kinetic fractionation and slow symbiont recolonization for several years after bleaching.

  7. Bacterial assemblages shifts from healthy to yellow band disease states in the dominant reef coral Montastraea faveolata.

    PubMed

    Cróquer, Aldo; Bastidas, Carolina; Elliott, Amy; Sweet, Michael

    2013-02-01

    Descriptions of microbial diversity in healthy and diseased corals are necessary first steps before further investigating the mechanisms that lead to coral pathology. This is the first study that characterizes the microbial associates from healthy corals to yellow band disease (YBD) lesions using two complementary screening techniques of bacterial 16S rRNA genes [amplified 16S ribosomal DNA restriction analysis (ARDRA) of clone libraries and denaturing gradient gel electrophoresis (DGGE)]. Both these techniques showed similar trends, namely a significant difference in the bacterial community and an increase in diversity from healthy to YBD diseased lesions. There was an increase in the number of sequences retrieved of potentially pathogenic bacteria in diseased tissues compared with healthy samples, most notably from the genus Vibrio. Furthermore, we also detected a number of known pathogenic bacteria within the natural healthy microbiota such as Vibrio carchariae and Vibrio harveyi, a result supporting previous studies, showing healthy corals have the ability to harbour these species. PMID:23757136

  8. Metagenomic and ecophysiological analysis of biofilms colonizing coral substrates: "Life after death of coral"

    NASA Astrophysics Data System (ADS)

    Sanchez, A., Sr.; Cerqueda-Garcia, D.; Falcón, L. I.; Iglesias-Prieto, R., Sr.

    2015-12-01

    Coral reefs are the most productive ecosystems on the planet and are the most important carbonated structures of biological origin. However, global warming is affecting the health and functionality of these ecosystems. Specifically, most of the Acropora sp. stony corals have declined their population all over the Mexican Caribbean in more than ~80% of their original coverage, resulting in vast extensions of dead coral rubble. When the coral dies, the skeleton begins to be colonized by algae, sponges, bacteria and others, forming a highly diverse biofilm. We analyzed the metagenomes of the dead A. palmata rubbles from Puerto Morelos, in the Mexican Caribbean. Also, we quantified the elemental composition of biomass and measured nitrogen fixation and emission of greenhouse gases over 24 hrs. This works provides information on how the community is composed and functions after the death of the coral, visualizing a possible picture for a world without coral reefs.

  9. Evolutionary insights into scleractinian corals using comparative genomic hybridizations

    PubMed Central

    2012-01-01

    Background Coral reefs belong to the most ecologically and economically important ecosystems on our planet. Yet, they are under steady decline worldwide due to rising sea surface temperatures, disease, and pollution. Understanding the molecular impact of these stressors on different coral species is imperative in order to predict how coral populations will respond to this continued disturbance. The use of molecular tools such as microarrays has provided deep insight into the molecular stress response of corals. Here, we have performed comparative genomic hybridizations (CGH) with different coral species to an Acropora palmata microarray platform containing 13,546 cDNA clones in order to identify potentially rapidly evolving genes and to determine the suitability of existing microarray platforms for use in gene expression studies (via heterologous hybridization). Results Our results showed that the current microarray platform for A. palmata is able to provide biological relevant information for a wide variety of coral species covering both the complex clade as well the robust clade. Analysis of the fraction of highly diverged genes showed a significantly higher amount of genes without annotation corroborating previous findings that point towards a higher rate of divergence for taxonomically restricted genes. Among the genes with annotation, we found many mitochondrial genes to be highly diverged in M. faveolata when compared to A. palmata, while the majority of nuclear encoded genes maintained an average divergence rate. Conclusions The use of present microarray platforms for transcriptional analyses in different coral species will greatly enhance the understanding of the molecular basis of stress and health and highlight evolutionary differences between scleractinian coral species. On a genomic basis, we show that cDNA arrays can be used to identify patterns of divergence. Mitochondrion-encoded genes seem to have diverged faster than nuclear encoded genes in robust

  10. Post-settlement survivorship in two Caribbean broadcasting corals

    NASA Astrophysics Data System (ADS)

    Miller, Margaret W.

    2014-12-01

    The post-settlement phase of broadcast-spawned coral life histories is poorly known due to its almost complete undetectability and, hence, presumed low abundance in the field. We used lab-cultured settled polyps of two important Caribbean reef-building species with negligible larval recruitment to quantify early post-settlement survivorship (6-9 weeks) over multiple years/cohorts and differing orientation on a reef in the Florida Keys. Orbicella faveolata showed significantly and consistently better survivorship in vertical rather than horizontal orientation, but no discernable growth overall. Meanwhile, Acropora palmata showed no significant difference in survivorship between orientations, but significantly greater growth in the horizontal orientation. Both species showed significant variation in mean survivorship between cohorts of different years; 0-47 % for O. faveolata and 12-49 % for A. palmata over the observed duration. These results demonstrate wide variation in success of cohorts and important differences in the larval recruitment capacities of these two important but imperiled reef-building species.

  11. Evidence for Multiple Phototransduction Pathways in a Reef-Building Coral

    PubMed Central

    Mason, Benjamin; Schmale, Michael; Gibbs, Patrick; Miller, Margaret W.; Wang, Qiang; Levay, Konstantin; Shestopalov, Valery; Slepak, Vladlen Z.

    2012-01-01

    Photosensitive behaviors and circadian rhythms are well documented in reef-building corals and their larvae, but the mechanisms responsible for photoreception have not been described in these organisms. Here we report the cloning, immunolocalization, and partial biochemical characterization of three opsins and four G proteins expressed in planulae of the Caribbean elkhorn coral, Acropora palmata. All three opsins (acropsins 1–3) possess conserved seven-pass transmembrane structure, and localize to distinct regions of coral planulae. Acropsin 1 was localized in the larval endoderm, while acropsin 2 was localized in solitary cells of the ectoderm. These rod-like cells displayed a remarkably polarized distribution, concentrated in the aboral end. We also cloned four A. palmata G protein alpha subunits. Three were homologs of vertebrate Gi, Go, and Gq. The fourth is presumably a novel G protein, which displays only 40% identity with the nearest known G protein, and we termed it Gc for “cnidarian”. We show that Gc and Gq can be activated by acropsins in a light-dependent manner in vitro. This indicates that at least acropsins 1 and 3 can form functional photoreceptors and potentially may play a role in color preference during settlement, vertical positioning and other light-guided behaviors observed in coral larvae. PMID:23227169

  12. Evidence for multiple phototransduction pathways in a reef-building coral.

    PubMed

    Mason, Benjamin; Schmale, Michael; Gibbs, Patrick; Miller, Margaret W; Wang, Qiang; Levay, Konstantin; Shestopalov, Valery; Slepak, Vladlen Z

    2012-01-01

    Photosensitive behaviors and circadian rhythms are well documented in reef-building corals and their larvae, but the mechanisms responsible for photoreception have not been described in these organisms. Here we report the cloning, immunolocalization, and partial biochemical characterization of three opsins and four G proteins expressed in planulae of the Caribbean elkhorn coral, Acropora palmata. All three opsins (acropsins 1-3) possess conserved seven-pass transmembrane structure, and localize to distinct regions of coral planulae. Acropsin 1 was localized in the larval endoderm, while acropsin 2 was localized in solitary cells of the ectoderm. These rod-like cells displayed a remarkably polarized distribution, concentrated in the aboral end. We also cloned four A. palmata G protein alpha subunits. Three were homologs of vertebrate Gi, Go, and Gq. The fourth is presumably a novel G protein, which displays only 40% identity with the nearest known G protein, and we termed it Gc for "cnidarian". We show that Gc and Gq can be activated by acropsins in a light-dependent manner in vitro. This indicates that at least acropsins 1 and 3 can form functional photoreceptors and potentially may play a role in color preference during settlement, vertical positioning and other light-guided behaviors observed in coral larvae.

  13. Evidence for multiple phototransduction pathways in a reef-building coral.

    PubMed

    Mason, Benjamin; Schmale, Michael; Gibbs, Patrick; Miller, Margaret W; Wang, Qiang; Levay, Konstantin; Shestopalov, Valery; Slepak, Vladlen Z

    2012-01-01

    Photosensitive behaviors and circadian rhythms are well documented in reef-building corals and their larvae, but the mechanisms responsible for photoreception have not been described in these organisms. Here we report the cloning, immunolocalization, and partial biochemical characterization of three opsins and four G proteins expressed in planulae of the Caribbean elkhorn coral, Acropora palmata. All three opsins (acropsins 1-3) possess conserved seven-pass transmembrane structure, and localize to distinct regions of coral planulae. Acropsin 1 was localized in the larval endoderm, while acropsin 2 was localized in solitary cells of the ectoderm. These rod-like cells displayed a remarkably polarized distribution, concentrated in the aboral end. We also cloned four A. palmata G protein alpha subunits. Three were homologs of vertebrate Gi, Go, and Gq. The fourth is presumably a novel G protein, which displays only 40% identity with the nearest known G protein, and we termed it Gc for "cnidarian". We show that Gc and Gq can be activated by acropsins in a light-dependent manner in vitro. This indicates that at least acropsins 1 and 3 can form functional photoreceptors and potentially may play a role in color preference during settlement, vertical positioning and other light-guided behaviors observed in coral larvae. PMID:23227169

  14. Caribbean Reef Response to Plio-Pleistocene Climate Change: Results of the Dominican Republic Drilling Project (DRDP)

    NASA Astrophysics Data System (ADS)

    Klaus, J.; McNeill, D. F.; Diaz, V.; Swart, P. K.; Pourmand, A.

    2014-12-01

    Caribbean reefs changed profoundly in taxonomic composition, diversity, and dominance structure during late Pliocene and Pleistocene climatic change. These changes coincide with protracted climatic deterioration and cooling between 2.0 to 0.8 Ma, and the onset of high amplitude sea-level fluctuations ~400 ka. The Dominican Republic Drilling Project (DRDP) was initiated to determine how climate change and global high-amplitude sea level changes influenced depositional patterns in Pliocene to Recent reef systems of the Caribbean. A transect of 7 core borings (~700 m total depth) were collected along the southern coast of the DR. New age constraints based on U/Th geochronometry and radiogenic Sr isotopes, combined with depositional lithofacies, faunal indicators, and stable isotope profiles have allowed us to correlate between wells and define the internal anatomy and stratal geometry of the individual reef sigmoids and sigmoid sets. Faunal records suggest most extinction occurred prior to ~1 Ma. Following this extinction, fringing reef margins of the Caribbean display a characteristic zonation in which Acropora palmata dominates shallow high-energy reef crests and Acropora cervicornis calmer fore-reef slopes and backreef lagoons. The dominance of acroporids across this zonation has been attributed to growth rates 5-100 times faster than other corals.

  15. Modern coral reefs of western Atlantic: new geological perspective

    SciTech Connect

    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.

  16. Accretion history of mid-Holocene coral reefs from the southeast Florida continental reef tract, USA

    NASA Astrophysics Data System (ADS)

    Stathakopoulos, A.; Riegl, B. M.

    2015-03-01

    Sixteen new coral reef cores were collected to better understand the accretion history and composition of submerged relict reefs offshore of continental southeast (SE) Florida. Coral radiometric ages from three sites on the shallow inner reef indicate accretion initiated by 8,050 Cal BP and terminated by 5,640 Cal BP. The reef accreted up to 3.75 m of vertical framework with accretion rates that averaged 2.53 m kyr-1. The reef was composed of a nearly even mixture of Acropora palmata and massive corals. In many cases, cores show an upward transition from massives to A. palmata and may indicate local dominance by this species prior to reef demise. Quantitative macroscopic analyses of reef clasts for various taphonomic and diagenetic features did not correlate well with depth/environmental-related trends established in other studies. The mixed coral framestone reef lacks a classical Caribbean reef zonation and is best described as an immature reef and/or a series of fused patch reefs; a pattern that is evident in both cores and reef morphology. This is in stark contrast to the older and deeper outer reef of the SE Florida continental reef tract. Accretion of the outer reef lasted from 10,695-8,000 Cal BP and resulted in a larger and better developed structure that achieved a distinct reef zonation. The discrepancies in overall reef morphology and size as well as the causes of reef terminations remain elusive without further study, yet they likely point to different climatic/environmental conditions during their respective accretion histories.

  17. Topography and spatial arrangement of reef-building corals on the fringing reefs of North Jamaica may influence their response to disturbance from bleaching.

    PubMed

    Crabbe, M J C

    2010-04-01

    Knowledge of factors that are important in reef resilience helps us understand how reefs react following major environmental disturbances such as hurricanes and bleaching. Here we test factors that might have influenced Jamaican reef resilience to, and subsequent recovery from, the 2005 bleaching event, and which might help inform management policy for reefs in the future: reef rugosity and contact of corals with macroalgae. In addition, we test in the field, on Dairy Bull reef, whether aggregated Porites astreoides colonies exhibit enhanced growth when exposed to superior competition from Acopora palmata, as has been found by experiment with the Indo-Pacific corals Porites lobata and the superior competitor Porites rus [Idjadi, J.A., Karlson, R.H., 2007. Spatial arrangement of competitors influences coexistence of reef-building corals. Ecology 88, 2449-2454]. There were significant linear relationships between rugosity and the increase in smallest size classes for Sidastrea siderea, Colpophyllia natans, P. astreoides and Agaricia species, and between rugosity and cover of the branching coral Acropora cervicornis. Linear extension rates of A. cervicornis and radial growth rates of P. astreoides were significantly lower (p<0.025; F>6) when in contact with macroalgae. Aggregated colonies of P. astreoides in contact with one another, one of which was in contact with the faster growing competitor A. palmata showed significantly greater growth rates than with just two aggregated P. astreoides colonies alone. These findings suggest that three dimensional topography and complexity is important for reef resilience and viability in the face of environmental stressors such as bleaching. Our findings also support the idea that aggregated spatial arrangements of corals can influence the outcome of interspecific competition and promote species coexistence, important in times of reef recovery after disturbance.

  18. Clues to Coral Reef Health: Integrating Radiative Transfer Modeling and Hyperspectral Data

    NASA Technical Reports Server (NTRS)

    Guild, Liane; Ganapol, Barry; Kramer, Philip; Armstrong, Roy; Gleason, Art; Torres, Juan; Johnson, Lee; Garfield, Toby; Peterson, David L. (Technical Monitor)

    2002-01-01

    An important contribution to coral reef research is to improve spectral distinction between various health states of coral species in areas subject to harmful anthropogenic activity and climate change. New insights into radiative transfer properties of corals under healthy and stressed conditions can advance understandings of ecological processes on reefs and allow better assessments of the impacts of large-scale bleaching and disease events, Our objective was to examine the spectral and spatial properties of hyperspectral sensors that may be used to remotely sense changes in reef community health. We compare in situ reef environment spectra (healthy coral, stressed coral, dead coral, algae, and sand) with airborne hyperspectral data to identify important spectral characteristics and indices. Additionally, spectral measurements over a range of water depths, relief, and bottom types are compared to help quantify bottom-water column influences. In situ spectra were collected in July and August 2002 at the Long Rock site in the Andros Island, Bahamas coastal zone coral reef. Our primary emphasis was on Acropora palmata (or elkhorn coral), a major reef building coral, which is prevalent in the study area, but is suffering from white band disease. A. palmata is currently being, proposed as an endangered species because its populations have severely declined in many areas of the Caribbean. In addition to the A. palmata biotope, we have collected spectra of at least seven other coral biotopes that exist within the study area, each with different coral community composition, density of corals, relief, and size of corals. Coral spectral reflectance was then input into a radiative transfer model, CORALMOD (CM1), which is based on a leaf radiative transfer model. In CM1, input coral reflectance measurements produce modeled reflectance through an inversion at each visible wavelength to provide the absorption spectrum. Initially, we imposed a scattering baseline that is the

  19. Brucite microbialites in living coral skeletons: Indicators of extreme microenvironments in shallow-marine settings

    NASA Astrophysics Data System (ADS)

    Nothdurft, Luke D.; Webb, Gregory E.; Buster, Noreen A.; Holmes, Charles W.; Sorauf, James E.; Kloprogge, J. T.

    2005-03-01

    Brucite [Mg(OH)2] microbialites occur in vacated interseptal spaces of living scleractinian coral colonies (Acropora, Pocillopora, Porites) from subtidal and intertidal settings in the Great Barrier Reef, Australia, and subtidal Montastraea from the Florida Keys, United States. Brucite encrusts microbial filaments of endobionts (i.e., fungi, green algae, cyanobacteria) growing under organic biofilms; the brucite distribution is patchy both within interseptal spaces and within coralla. Although brucite is undersaturated in seawater, its precipitation was apparently induced in the corals by lowered pCO2 and increased pH within microenvironments protected by microbial biofilms. The occurrence of brucite in shallow-marine settings highlights the importance of microenvironments in the formation and early diagenesis of marine carbonates. Significantly, the brucite precipitates discovered in microenvironments in these corals show that early diagenetic products do not necessarily reflect ambient seawater chemistry. Errors in environmental interpretation may arise where unidentified precipitates occur in microenvironments in skeletal carbonates that are subsequently utilized as geochemical seawater proxies.

  20. Brucite microbialites in living coral skeletons: Indicators of extreme microenvironments in shallow-marine settings

    USGS Publications Warehouse

    Nothdurft, L.D.; Webb, G.E.; Buster, N.A.; Holmes, C.W.; Sorauf, J.E.; Kloprogge, J.T.

    2005-01-01

    Brucite [Mg(OH)2] microbialites occur in vacated interseptal spaces of living scleractinian coral colonies (Acropora, Pocillopora, Porites) from subtidal and intertidal settings in the Great Barrier Reef, Australia, and subtidal Montastraea from the Florida Keys, United States. Brucite encrusts microbial filaments of endobionts (i.e., fungi, green algae, cyanobacteria) growing under organic biofilms; the brucite distribution is patchy both within interseptal spaces and within coralla. Although brucite is undersaturated in seawater, its precipitation was apparently induced in the corals by lowered pCO 2 and increased pH within microenvironments protected by microbial biofilms. The occurrence of brucite in shallow-marine settings highlights the importance of microenvironments in the formation and early diagenesis of marine carbonates. Significantly, the brucite precipitates discovered in microenvironments in these corals show that early diagenetic products do not necessarily reflect ambient seawater chemistry. Errors in environmental interpretation may arise where unidentified precipitates occur in microenvironments in skeletal carbonates that are subsequently utilized as geochemical seawater proxies. ?? 2005 Geological Society of America.

  1. Photoreception and signal transduction in corals: proteomic and behavioral evidence for cytoplasmic calcium as a mediator of light responsivity.

    PubMed

    Hilton, J Daniel; Brady, Aisling K; Spaho, Skender A; Vize, Peter D

    2012-12-01

    Little is known about how corals sense and respond to light. In this report the proteome of coral is explored using 2D protein electrophoresis in two species, Montastraea cavernosa and Acropora millepora. Multiple protein species have major shifts in abundance in both species when sampled in daylight compared to corals sampled late in the night. These changes were observed both in larvae lacking zooxanthellae and in adult tissue containing zooxanthellae, including both Pacific and Caribbean corals. When larvae kept in the dark were treated with either thapsigargin or ionomycin, compounds that raise the level of cytoplasmic calcium, the night pattern of proteins shifted to the day pattern. This implies that photoreceptors responding to light elevate calcium levels and that calcium acts as the second messenger relaying light responses in corals. Corals spawn at night, and spawning can be delayed by exposure to light or pushed forward by early artificial sunsets. In a series of behavioral experiments, treatment of corals with ionomycin or thapsigargin was found to delay broadcast spawning in M. franksi, demonstrating that pharmacologically altering cytoplasmic calcium levels generates the same response as light exposure. Together these results show that the photo-responsive cells of corals detect and respond to light by altering cytoplasmic calcium levels, similarly to the transduction pathways in complex invertebrate eyes. The primacy of cytoplasmic calcium levels in light responsivity has broad implications for coral reproduction, including predicting how different species spawn at different times after sunset and how reproductive isolation is achieved during coral speciation.

  2. Changing Patterns of Microhabitat Utilization by the Threespot Damselfish, Stegastes planifrons, on Caribbean Reefs

    PubMed Central

    Precht, William F.; Aronson, Richard B.; Moody, Ryan M.; Kaufman, Les

    2010-01-01

    Background The threespot damselfish, Stegastes planifrons (Cuvier), is important in mediating interactions among corals, algae, and herbivores on Caribbean coral reefs. The preferred microhabitat of S. planifrons is thickets of the branching staghorn coral Acropora cervicornis. Within the past few decades, mass mortality of A. cervicornis from white-band disease and other factors has rendered this coral a minor ecological component throughout most of its range. Methodology/Principal Findings Survey data from Jamaica (heavily fished), Florida and the Bahamas (moderately fished), the Cayman Islands (lightly to moderately fished), and Belize (lightly fished) indicate that distributional patterns of S. planifrons are positively correlated with live coral cover and topographic complexity. Our results suggest that species-specific microhabitat preferences and the availability of topographically complex microhabitats are more important than the abundance of predatory fish as proximal controls on S. planifrons distribution and abundance. Conclusions/Significance The loss of the primary microhabitat of S. planifrons—A. cervicornis—has forced a shift in the distribution and recruitment of these damselfish onto remaining high-structured corals, especially the Montastraea annularis species complex, affecting coral mortality and algal dynamics throughout the Caribbean. PMID:20520809

  3. Genomic and microarray approaches to coral reef conservation biology

    NASA Astrophysics Data System (ADS)

    Forêt, S.; Kassahn, K. S.; Grasso, L. C.; Hayward, D. C.; Iguchi, A.; Ball, E. E.; Miller, D. J.

    2007-09-01

    New technologies based on DNA microarrays and comparative genomics hold great promise for providing the background biological information necessary for effective coral reef conservation and management. Microarray analysis has been used in a wide range of applications across the biological sciences, most frequently to examine simultaneous changes in the expression of large numbers of genes in response to experimental manipulation or environmental variation. Other applications of microarray methods include the assessment of divergence in gene sequences between species and the identification of fast-evolving genes. Arrays are presently available for only a limited range of species, but with appropriate controls they can be used for related species, thus avoiding the considerable costs associated with development of a system de novo. Arrays are in use or preparation to study stress responses, early development, and symbiosis in Acropora and Montastraea. Ongoing projects on several corals are making available large numbers of expressed gene sequences, enabling the identification of candidate genes for studies on gamete specificity, allorecognition and symbiont interactions. Over the next few years, microarray and comparative genomic approaches are likely to assume increasingly important and widespread use to study many aspects of the biology of coral reef organisms. Application of these genomic approaches to enhance our understanding of genetic and physiological correlates during stress, environmental disturbance and disease bears direct relevance to the conservation of coral reef ecosystems.

  4. Pliocene-Lower Pleistocene shallow-water mixed siliciclastics and carbonates (Yanigua and Los Haitises formations) in eastern Hispaniola (Dominican Republic)

    NASA Astrophysics Data System (ADS)

    Braga, Juan C.; Díaz de Neira, Alberto; Lasseur, Eric; Mediato, José; Aguirre, Julio; Abad, Manuel; Hernaiz-Huerta, Pedro P.; Monthel, Jacques; Pérez-Valera, Fernando; Lopera, Eusebio

    2012-07-01

    The virtually unfolded sedimentary cover of the Cordilleras Central and Oriental in the eastern Dominican Republic (eastern Hispaniola, tropical North Atlantic) largely consists of Pliocene to Early Pleistocene mixed siliciclastics and carbonates. These deposits have been grouped into two laterally interfingering mapping units, the Yanigua and Los Haitises formations. The former (mainly siliciclastics) comprises marl, marly limestone, and minor conglomerate, sandstone, lignite, and carbonaceous clay and crops out closest to the basement. The Los Haitises Formation mainly consists of limestone and intercalating beds of marly limestone and marl. Lithological mapping at the 1:50,000 scale and facies analysis of twelve measured sections and of additional fourteen outcrops suggest that these deposits mainly formed on a shallow-water marine platform fringing the precursor reliefs of the Cordillera Oriental and the southeastern end of the Cordillera Central. Only a limited proportion of sediment formed in floodplains and marshes. Marl and marly limestone dominated the inner platform sediments. Terrigenous mud decreased away from the emergent basement and carbonate sedimentation dominated the more external platform. Corals, molluscs, echinoids, foraminifers, bryozoans, coralline algae, and Halimeda are the main components with varying amounts of carbonate mud. The platform was generally a low-energy environment with seagrass patches. In the inner platform, corals grew as isolated colonies or as small patch reefs dominated by Porites in marly and bioclastic substrates. Branching corals (Stylophora and Acropora) grew in extensive carpets in more distal areas. At least in the last stage of its development (Early Pleistocene), the platform was rimmed by a reef barrier similar to the Holocene Caribbean barrier reefs, with Acropora gr. palmata, A. cervicornis, Porites, Montastrea, Siderastrea, and Diploria as the main reef builders.

  5. Rapid Evolution of Coral Proteins Responsible for Interaction with the Environment

    SciTech Connect

    Voolstra, Christian R.; Sunagawa, Shinichi; Matz, Mikhail V.; Bayer, Till; Aranda, Manuel; Buschiazzo, Emmanuel; DeSalvo, Michael K.; Lindquist, Erika; Szmant, Alina M.; Coffroth, Mary Alice; Medina, Monica

    2011-01-31

    Background: Corals worldwide are in decline due to climate change effects (e.g., rising seawater temperatures), pollution, and exploitation. The ability of corals to cope with these stressors in the long run depends on the evolvability of the underlying genetic networks and proteins, which remain largely unknown. A genome-wide scan for positively selected genes between related coral species can help to narrow down the search space considerably. Methodology/Principal Findings: We screened a set of 2,604 putative orthologs from EST-based sequence datasets of the coral species Acropora millepora and Acropora palmata to determine the fraction and identity of proteins that may experience adaptive evolution. 7percent of the orthologs show elevated rates of evolution. Taxonomically-restricted (i.e. lineagespecific) genes show a positive selection signature more frequently than genes that are found across many animal phyla. The class of proteins that displayed elevated evolutionary rates was significantly enriched for proteins involved in immunity and defense, reproduction, and sensory perception. We also found elevated rates of evolution in several other functional groups such as management of membrane vesicles, transmembrane transport of ions and organic molecules, cell adhesion, and oxidative stress response. Proteins in these processes might be related to the endosymbiotic relationship corals maintain with dinoflagellates in the genus Symbiodinium. Conclusion/Relevance: This study provides a birds-eye view of the processes potentially underlying coral adaptation, which will serve as a foundation for future work to elucidate the rates, patterns, and mechanisms of corals? evolutionary response to global climate change.

  6. The Changing Face of Plio-Pleistocene Reef Margins: Results of the Dominican Republic Drilling Project (DRDP)

    NASA Astrophysics Data System (ADS)

    Klaus, J.; McNeill, D. F.; Díaz, V.; Swart, P. K.; Pourmand, A.; Grasmueck, M.; Eberli, G. P.

    2013-12-01

    Fringing reef margins of the Caribbean display a characteristic zonation in which Acropora palmata dominates shallow high-energy reef crests and Acropora cervicornis calmer fore-reef slopes and backreef lagoons. The dominance of acroporids across this zonation has been attributed to growth rates 5-100 times faster than other corals. However, the dominance and high accretion potential of acroporid reefs has a relatively recent geologic origin. Caribbean reefs changed profoundly in taxonomic composition, diversity, and dominance structure during late Pliocene and Pleistocene climatic change. These changes coincide with protracted climatic deterioration and cooling between 2.0 to 0.8 Ma, and the onset of high amplitude sea-level fluctuations ~400 ka. The Dominican Republic Drilling Project (DRDP) was initiated to determine how climate change and global high-amplitude sea level changes influenced depositional patterns in Pliocene to Recent reef systems of the Caribbean. A transect of 7 core borings (~700 m total depth) were collected along a transect of the southern coast of the DR in conjunction with over 20 km of ground penetrating radar (GPR) lines. New age constraints based on U/Th geochronometry and radiogenic Sr isotopes, combined with depositional lithofacies, faunal indicators, stable isotope profiles and GPR data have allowed us to correlate between wells and define the internal anatomy and stratal geometry of the individual reef sigmoids and sigmoid sets. The stacking of these sigmoid-shaped reefs produce lateral progradation of approximately 15 km with geometries that generally follow the highstand systems tract model of Pomar and Ward (1994). Based on existing age models eccentricity (high amplitude 100 kyr) sigmoids display increased aggradation and progradation potential compared to reef cycles driven by obliquity (41 kyr).

  7. Holocene coral patch reef ecology and sedimentary architecture, Northern Belize, Central America

    SciTech Connect

    Mazzullo, S.J.; Anderson-Underwood, K.E.; Burke, C.D.; Bischoff, W.D. )

    1992-12-01

    Coral patch reefs are major components of Holocene platform carbonate facies systems in tropical and subtropical areas. The biotic composition, growth and relationship to sea level history, and diagenetic attributes of a representative Holocene patch reef ([open quotes]Elmer Reef[close quotes]) in the Mexico Rocks complex in northern Belize are described and compared to those of Holocene patch reefs in southern Belize. Elmer Reef has accumulated in shallow (2.5 m) water over the last 420 yr, under static sea level conditions. Rate of vertical construction is 0.3-0.5 m/100 yr, comparable to that of patch reefs in southern Belize. A pronounced coral zonation exists across Elmer Reef, with Monastrea annularis dominating on its crest and Acropora cervicornis occurring on its windward and leeward flanks. The dominance of Montastrea on Elmer Reef is unlike that of patch reefs in southern Belize, in which this coral assumes only a subordinate role in reef growth relative to that of Acropora palmata. Elmer Reef locally is extensively biodegraded and marine, fibrous aragonite and some bladed high-magnesium calcite cements occur throughout the reef section, partially occluding corallites and interparticle pores in associated sands. Patch reefs in southern Belize have developed as catch-up and keep-up reefs in a transgressive setting. In contrast, the dominant mode of growth of Elmer Reef, and perhaps other patch reefs in Mexico Rocks, appears to be one of lateral rather than vertical accretion. This style of growth occurs in a static sea level setting where there is only limited accommodation space because of the shallowness of the water, and such reefs are referred to as [open quotes]expansion reefs[close quotes]. 39 refs., 8 figs., 2 tabs.

  8. Acclimatization to high-variance habitats does not enhance physiological tolerance of two key Caribbean corals to future temperature and pH.

    PubMed

    Camp, Emma F; Smith, David J; Evenhuis, Chris; Enochs, Ian; Manzello, Derek; Woodcock, Stephen; Suggett, David J

    2016-05-25

    Corals are acclimatized to populate dynamic habitats that neighbour coral reefs. Habitats such as seagrass beds exhibit broad diel changes in temperature and pH that routinely expose corals to conditions predicted for reefs over the next 50-100 years. However, whether such acclimatization effectively enhances physiological tolerance to, and hence provides refuge against, future climate scenarios remains unknown. Also, whether corals living in low-variance habitats can tolerate present-day high-variance conditions remains untested. We experimentally examined how pH and temperature predicted for the year 2100 affects the growth and physiology of two dominant Caribbean corals (Acropora palmata and Porites astreoides) native to habitats with intrinsically low (outer-reef terrace, LV) and/or high (neighbouring seagrass, HV) environmental variance. Under present-day temperature and pH, growth and metabolic rates (calcification, respiration and photosynthesis) were unchanged for HV versus LV populations. Superimposing future climate scenarios onto the HV and LV conditions did not result in any enhanced tolerance to colonies native to HV. Calcification rates were always lower for elevated temperature and/or reduced pH. Together, these results suggest that seagrass habitats may not serve as refugia against climate change if the magnitude of future temperature and pH changes is equivalent to neighbouring reef habitats.

  9. Caribbean corals house shared and host-specific microbial symbionts over time and space.

    PubMed

    Chu, Nathaniel D; Vollmer, Steven V

    2016-08-01

    The rise of coral diseases has triggered a surge of interest in coral microbial communities. But to fully understand how the coral microbiome may cause or respond to disease, we must first understand structure and variation in the healthy coral microbiome. We used 16S rRNA sequencing to characterize the microbiomes of 100 healthy coral colonies from six Caribbean coral species (Acropora cervicornis, A. palmata, Diploria labyrinthiformis, Diploria strigosa, Porites astreoides and P. furcata) across four reefs and three time points over 1 year. We found host species to be the strongest driver of coral microbiome structure across site and time. Analysis of the core microbiome revealed remarkable similarity in the bacterial taxa represented across coral hosts and many bacterial phylotypes shared across all corals sampled. Some of these widespread bacterial taxa have been identified in Pacific corals, indicating that a core coral microbiome may extend across oceans. Core bacterial phylotypes that were unique to each coral were taxonomically diverse, suggesting that different coral hosts provide persistent, divergent niches for bacteria. PMID:27083502

  10. Acclimatization to high-variance habitats does not enhance physiological tolerance of two key Caribbean corals to future temperature and pH.

    PubMed

    Camp, Emma F; Smith, David J; Evenhuis, Chris; Enochs, Ian; Manzello, Derek; Woodcock, Stephen; Suggett, David J

    2016-05-25

    Corals are acclimatized to populate dynamic habitats that neighbour coral reefs. Habitats such as seagrass beds exhibit broad diel changes in temperature and pH that routinely expose corals to conditions predicted for reefs over the next 50-100 years. However, whether such acclimatization effectively enhances physiological tolerance to, and hence provides refuge against, future climate scenarios remains unknown. Also, whether corals living in low-variance habitats can tolerate present-day high-variance conditions remains untested. We experimentally examined how pH and temperature predicted for the year 2100 affects the growth and physiology of two dominant Caribbean corals (Acropora palmata and Porites astreoides) native to habitats with intrinsically low (outer-reef terrace, LV) and/or high (neighbouring seagrass, HV) environmental variance. Under present-day temperature and pH, growth and metabolic rates (calcification, respiration and photosynthesis) were unchanged for HV versus LV populations. Superimposing future climate scenarios onto the HV and LV conditions did not result in any enhanced tolerance to colonies native to HV. Calcification rates were always lower for elevated temperature and/or reduced pH. Together, these results suggest that seagrass habitats may not serve as refugia against climate change if the magnitude of future temperature and pH changes is equivalent to neighbouring reef habitats. PMID:27194698

  11. Intraspecific diversity among partners drives functional variation in coral symbioses

    PubMed Central

    Parkinson, John Everett; Banaszak, Anastazia T.; Altman, Naomi S.; LaJeunesse, Todd C.; Baums, Iliana B.

    2015-01-01

    The capacity of coral-dinoflagellate mutualisms to adapt to a changing climate relies in part on standing variation in host and symbiont populations, but rarely have the interactions between symbiotic partners been considered at the level of individuals. Here, we tested the importance of inter-individual variation with respect to the physiology of coral holobionts. We identified six genetically distinct Acropora palmata coral colonies that all shared the same isoclonal Symbiodinium ‘fitti’ dinoflagellate strain. No other Symbiodinium could be detected in host tissues. We exposed fragments of each colony to extreme cold and found that the stress-induced change in symbiont photochemical efficiency varied up to 3.6-fold depending on host genetic background. The S. ‘fitti’ strain was least stressed when associating with hosts that significantly altered the expression of 184 genes under cold shock; it was most stressed in hosts that only adjusted 14 genes. Key expression differences among hosts were related to redox signaling and iron availability pathways. Fine-scale interactions among unique host colonies and symbiont strains provide an underappreciated source of raw material for natural selection in coral symbioses. PMID:26497873

  12. Spurs and grooves revisited: construction versus erosion, Looe Key Reef, Florida

    USGS Publications Warehouse

    Shinn, E.A.; Hudson, J.H.; Robbin, Daniel M.; Lidz, Barbara H.; Gomez, Edgardo D.; Birkeland, C.E.; Buddemeier, R.W.; Johannes, R.E.; Marsh, J. A.; Tsuda, R.T.

    1982-01-01

    Six of 12 core holes drilled at Looe Key Reef (24°37'18"N. 81°24'24"W) by a diver-operated coring device penetrated a spur and groove system. Drilling indicated that: (II the spurs and grooves formed over at least 5 m of carbonate reef sand: (2) the underlying Pleistocene surface is essentially flat and therefore could not control or initiate spacing of spurs or grooves; (3) only the thin seaward ends of spurs are rooted on underlying bedrock: and (4) the interior of the Millepora-encrusted spurs is composed primarily of Acropora palmata. a species no longer abundant on this reef. From the drilling of Looe Key Reef and from other observations along the reef tract, we propose that most shallow spurs and grooves in active coral reef areas of the Caribbean are constructional in origin and not initiated or controlled by bedrock topography. Spurs and grooves in non-coral reef areas adjacent to shorelines, however. are clearly of erosional origin and have a close spacing distinctly different from spurs and grooves known to be of constructional origin. These observations indicate that spurs and grooves in deeper (> 15 m) fore-reef areas off Florida, which have the same geometry as the shoreline features. are erosional in origin and therefore formed on a shoreline during a lower stand of sea level.

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

    SciTech Connect

    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.

  14. Characterization of the gacA-dependent surface and coral mucus colonization by an opportunistic coral pathogen Serratia marcescens PDL100.

    PubMed

    Krediet, Cory J; Carpinone, Emily M; Ritchie, Kim B; Teplitski, Max

    2013-05-01

    Opportunistic pathogens rely on global regulatory systems to assess the environment and to control virulence and metabolism to overcome host defenses and outcompete host-associated microbiota. In Gammaproteobacteria, GacS/GacA is one such regulatory system. GacA orthologs direct the expression of the csr (rsm) small regulatory RNAs, which through their interaction with the RNA-binding protein CsrA (RsmA), control genes with functions in carbon metabolism, motility, biofilm formation, and virulence. The csrB gene was controlled by gacA in Serratia marcescens PDL100. A disruption of the S. marcescens gacA gene resulted in an increased fitness of the mutant on mucus of the host coral Acropora palmata and its high molecular weight fraction, whereas the mutant was as competitive as the wild type on the low molecular weight fraction of the mucus. Swarming motility and biofilm formation were reduced in the gacA mutant. This indicates a critical role for gacA in the efficient utilization of specific components of coral mucus and establishment within the surface mucopolysaccharide layer. While significantly affecting early colonization behaviors (coral mucus utilization, swarming motility, and biofilm formation), gacA was not required for virulence of S. marcescens PDL100 in either a model polyp Aiptasia pallida or in brine shrimp Artemia nauplii.

  15. Intraspecific diversity among partners drives functional variation in coral symbioses.

    PubMed

    Parkinson, John Everett; Banaszak, Anastazia T; Altman, Naomi S; LaJeunesse, Todd C; Baums, Iliana B

    2015-10-26

    The capacity of coral-dinoflagellate mutualisms to adapt to a changing climate relies in part on standing variation in host and symbiont populations, but rarely have the interactions between symbiotic partners been considered at the level of individuals. Here, we tested the importance of inter-individual variation with respect to the physiology of coral holobionts. We identified six genetically distinct Acropora palmata coral colonies that all shared the same isoclonal Symbiodinium 'fitti' dinoflagellate strain. No other Symbiodinium could be detected in host tissues. We exposed fragments of each colony to extreme cold and found that the stress-induced change in symbiont photochemical efficiency varied up to 3.6-fold depending on host genetic background. The S. 'fitti' strain was least stressed when associating with hosts that significantly altered the expression of 184 genes under cold shock; it was most stressed in hosts that only adjusted 14 genes. Key expression differences among hosts were related to redox signaling and iron availability pathways. Fine-scale interactions among unique host colonies and symbiont strains provide an underappreciated source of raw material for natural selection in coral symbioses.

  16. Interactions between the tropical sea anemone Aiptasia pallida and Serratia marcescens, an opportunistic pathogen of corals.

    PubMed

    Krediet, Cory J; Meyer, Julie L; Gimbrone, Nicholas; Yanong, Roy; Berzins, Ilze; Alagely, Ali; Castro, Herman; Ritchie, Kim B; Paul, Valerie J; Teplitski, Max

    2014-06-01

    Coral reefs are under increasing stress caused by global and local environmental changes, which are thought to increase the susceptibility of corals to opportunistic pathogens. In the absence of an easily culturable model animal, the understanding of the mechanisms of disease progression in corals remains fairly limited. In the present study, we tested the susceptibility of the tropical sea anemone Aiptasia pallida to an opportunistic coral pathogen (Serratia marcescens). A. pallida was susceptible to S. marcescens PDL100 and responded to this opportunistic coral pathogen with darkening of the tissues and retraction of tentacles, followed by complete disintegration of polyp tissues. Histological observations revealed loss of zooxanthellae and structural changes in eosinophilic granular cells in response to pathogen infection. A screen of S. marcescens mutants identified a motility and tetrathionate reductase mutants as defective in virulence in the A. pallida infection model. In co-infections with the wild-type strain, the tetrathionate reductase mutant was less fit within the surface mucopolysaccharide layer of the host coral Acropora palmata.

  17. Use of quantitative real-time PCR for direct detection of serratia marcescens in marine and other aquatic environments.

    PubMed

    Joyner, Jessica; Wanless, David; Sinigalliano, Christopher D; Lipp, Erin K

    2014-03-01

    Serratia marcescens is the etiological agent of acroporid serratiosis, a distinct form of white pox disease in the threatened coral Acropora palmata. The pathogen is commonly found in untreated human waste in the Florida Keys, which may contaminate both nearshore and offshore waters. Currently there is no direct method for detection of this bacterium in the aquatic or reef environment, and culture-based techniques may underestimate its abundance in marine waters. A quantitative real-time PCR assay was developed to detect S. marcescens directly from environmental samples, including marine water, coral mucus, sponge tissue, and wastewater. The assay targeted the luxS gene and was able to distinguish S. marcescens from other Serratia species with a reliable quantitative limit of detection of 10 cell equivalents (CE) per reaction. The method could routinely discern the presence of S. marcescens for as few as 3 CE per reaction, but it could not be reliably quantified at this level. The assay detected environmental S. marcescens in complex sewage influent samples at up to 761 CE ml(-1) and in septic system-impacted residential canals in the Florida Keys at up to 4.1 CE ml(-1). This detection assay provided rapid quantitative abilities and good sensitivity and specificity, which should offer an important tool for monitoring this ubiquitous pathogen that can potentially impact both human health and coral health.

  18. A matter of scale: damage from Hurricane Hugo (1989) to U.S. Virgin Islands reefs at the colony, community and whole reef level

    USGS Publications Warehouse

    Rogers, Caroline S.

    1993-01-01

    Studies at Buck Island Reef National Monument (St. Croix) and Virgin Islands National Park (St. John) by scientists in the U.S. National Park Service Coral Reef Assessment Program re- vealed the effects of Humcane Hugo on individual coral species, community parameters, and overall reef structure. Effects of the storm varied with depth, coral species, location relative to the storm path, character of the pre-storm communities, and ecological history. Live coral cover, initially less than 30% at all sites, dropped by 40 to 73%. Cover by the dominant species Montastrea annularis de- clined about 35% on the St. John reefs. At Buck Island, Acropora palmata cover, already reduced from 85% to 5% by white band disease and storms, fell to 0.8% after Hugo. Some areas on the south side of Buck Island were reduced to rubble pave- ment while other areas escaped serious damage. Data from cores at Buck Island reveal the influence of wave energy and storm frequency on overall reef character. Patchiness and variation in the responses of different species, zones, and entire reefs to the storm suggest that assessment of long-term trends in reef structure and composition requires analysis of changes at permanent study sites distributed over large areas.

  19. ANALYSIS OF GENETIC VARIATION IN GUAM POPULATIONS OF THE MASS SPAWNING CORAL ACROPORA SURCULOSA USING RAPDS. (R825158)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Comparing the effects of symbiotic algae (Symbiodinium) clades C1 and D on early growth stages of Acropora tenuis.

    PubMed

    Yuyama, Ikuko; Higuchi, Tomihiko

    2014-01-01

    Reef-building corals switch endosymbiotic algae of the genus Symbiodinium during their early growth stages and during bleaching events. Clade C Symbiodinium algae are dominant in corals, although other clades - including A and D - have also been commonly detected in juvenile Acroporid corals. Previous studies have been reported that only molecular data of Symbiodinium clade were identified within field corals. In this study, we inoculated aposymbiotic juvenile polyps with cultures of clades C1 and D Symbiodinium algae, and investigated the different effect of these two clades of Symbiodinium on juvenile polyps. Our results showed that clade C1 algae did not grow, while clade D algae grew rapidly during the first 2 months after inoculation. Polyps associated with clade C1 algae exhibited bright green fluorescence across the body and tentacles after inoculation. The growth rate of polyp skeletons was lower in polyps associated with clade C1 algae than those associated with clade D algae. On the other hand, antioxidant activity (catalase) of corals was not significantly different between corals with clade C1 and clade D algae. Our results suggested that clade D Symbiodinium algae easily form symbiotic relationships with corals and that these algae could contribute to coral growth in early symbiosis stages.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  2. Expanding the population genetic perspective of cnidarian-Symbiodinium symbioses.

    PubMed

    Santos, Scott R

    2014-09-01

    understanding of the current genotypic diversity encompassed within and between populations of their keystone species, the scleractinian corals and dinoflagellate symbionts, as they potentially possess functional variation (either singularly or in combination) that may come under selection due to the ongoing and rapid environmental changes they are experiencing. However, such studies, especially for members of the genus Symbiodinium, are sparse. In this issue, Baums et al. (2014) provide a significant contribution by documenting the range-wide population genetics of Symbiodinium 'fitti' (Fig.1 ) in the context of complementary data from its host, the endangered Caribbean elkhorn coral Acropora palmata (Fig. 2). Notable results of this study include a single S. 'fitti' genotype typically dominates an individual A. palmata colony both spatially and temporally, gene flow among coral host populations is a magnitude higher to that of its symbiont populations, and the partners possess disparate patterns of genetic differentiation across the Greater Caribbean. The implications of such findings are discussed herein.

  3. Atlantic Warm Pool Trigger for the Younger Dryas Climate Event

    NASA Astrophysics Data System (ADS)

    Abdul, N. A.; Mortlock, R. A.; Wright, J. D.; Fairbanks, R. G.; Teneva, L. T.

    2011-12-01

    There is growing evidence that variability in the size and heat content of the tropical Atlantic Warm Pool impacts circum-North Atlantic climate via the Atlantic Multi-decadal Oscillation mode (Wang et al., 2008). The Atlantic Warm Pool spans the Gulf of Mexico, Caribbean Sea and the western tropical North Atlantic. Barbados is located near the center of the tropical Atlantic Warm Pool and coupled ocean models suggest that Barbados remains near the center of the tropical Atlantic Warm Pool under varying wind stress simulations. Measurements of the oxygen isotope paleothermometer in Acropora palmata coral species recovered from cores offshore Barbados, show a 3oC monotonic decrease in sea surface temperature from 13106 ± 83 to 12744 ± 61 years before present (errors given as 2 sigma). This interval corresponds to a sea level rise from 71.4 meters to 67.1 meters below present levels at Barbados. The 3oC temperature decrease is captured in eight A. palmata specimens that are in stratigraphic sequence, 230Th/234U dated, and analyzed for oxygen isotopes. All measurements are replicated. We are confident that this is the warm pool equivalent of the Younger Dryas climate event. The initiation of this temperature drop in the Atlantic Warm Pool predates the Younger Dryas start in Greenland ice cores, reported to start at 12896 ± 138 years (relative to AD 2000) (Rasmussen et al., 2006), while few other Younger Dryas climate records are dated with similar accuracy to make the comparison. Rasmussen, S.O., Andersen, K.K., Svensson, A.M., Steffensen, J.P., Vinther, B.M., Clausen, H.B., Siggaard-Andersen, M.L., Johnsen, S.J., Larsen, L.B., Dahl-Jensen, D., Bigler, M., Röthlisberger, R., Fischer, H., Goto-Azuma, K., Hansson, M.E., and Ruth, U., 2006, A new Greenland ice core chronology for the last glacial termination: J. Geophys. Res., v. 111, p. D06102. Wang, C., Lee, S.-K., and Enfield, D.B., 2008, Atlantic Warm Pool acting as a link between Atlantic Multidecadal

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

    USGS Publications Warehouse

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

    2016-07-21

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

  5. Expanding the population genetic perspective of cnidarian-Symbiodinium symbioses.

    PubMed

    Santos, Scott R

    2014-09-01

    understanding of the current genotypic diversity encompassed within and between populations of their keystone species, the scleractinian corals and dinoflagellate symbionts, as they potentially possess functional variation (either singularly or in combination) that may come under selection due to the ongoing and rapid environmental changes they are experiencing. However, such studies, especially for members of the genus Symbiodinium, are sparse. In this issue, Baums et al. (2014) provide a significant contribution by documenting the range-wide population genetics of Symbiodinium 'fitti' (Fig.1 ) in the context of complementary data from its host, the endangered Caribbean elkhorn coral Acropora palmata (Fig. 2). Notable results of this study include a single S. 'fitti' genotype typically dominates an individual A. palmata colony both spatially and temporally, gene flow among coral host populations is a magnitude higher to that of its symbiont populations, and the partners possess disparate patterns of genetic differentiation across the Greater Caribbean. The implications of such findings are discussed herein. PMID:25155714

  6. Identification and Gene Expression Analysis of a Taxonomically Restricted Cysteine-Rich Protein Family in Reef-Building Corals

    PubMed Central

    Sunagawa, Shinichi; DeSalvo, Michael K.; Voolstra, Christian R.; Reyes-Bermudez, Alejandro; Medina, Mónica

    2009-01-01

    The amount of genomic sequence information continues to grow at an exponential rate, while the identification and characterization of genes without known homologs remains a major challenge. For non-model organisms with limited resources for manipulative studies, high-throughput transcriptomic data combined with bioinformatics methods provide a powerful approach to obtain initial insights into the function of unknown genes. In this study, we report the identification and characterization of a novel family of putatively secreted, small, cysteine-rich proteins herein named Small Cysteine-Rich Proteins (SCRiPs). Their discovery in expressed sequence tag (EST) libraries from the coral Montastraea faveolata required the performance of an iterative search strategy based on BLAST and Hidden-Markov-Model algorithms. While a discernible homolog could neither be identified in the genome of the sea anemone Nematostella vectensis, nor in a large EST dataset from the symbiotic sea anemone Aiptasia pallida, we identified SCRiP sequences in multiple scleractinian coral species. Therefore, we postulate that this gene family is an example of lineage-specific gene expansion in reef-building corals. Previously published gene expression microarray data suggest that a sub-group of SCRiPs is highly responsive to thermal stress. Furthermore, data from microarray experiments investigating developmental gene expression in the coral Acropora millepora suggest that different SCRiPs may play distinct roles in the development of corals. The function of these proteins remains to be elucidated, but our results from in silico, transcriptomic, and phylogenetic analyses provide initial insights into the evolution of SCRiPs, a novel, taxonomically restricted gene family that may be responsible for a lineage-specific trait in scleractinian corals. PMID:19283069

  7. Survival dynamics of scleractinian coral larvae and implications for dispersal

    NASA Astrophysics Data System (ADS)

    Graham, E. M.; Baird, A. H.; Connolly, S. R.

    2008-09-01

    Survival of pelagic marine larvae is an important determinant of dispersal potential. Despite this, few estimates of larval survival are available. For scleractinian corals, few studies of larval survival are long enough to provide accurate estimates of longevity. Moreover, changes in mortality rates during larval life, expected on theoretical grounds, have implications for the degree of connectivity among reefs and have not been quantified for any coral species. This study quantified the survival of larvae from five broadcast-spawning scleractinian corals ( Acropora latistella, Favia pallida, Pectinia paeonia, Goniastrea aspera, and Montastraea magnistellata) to estimate larval longevity, and to test for changes in mortality rates as larvae age. Maximum lifespans ranged from 195 to 244 d. These longevities substantially exceed those documented previously for coral larvae that lack zooxanthellae, and they exceed predictions based on metabolic rates prevailing early in larval life. In addition, larval mortality rates exhibited strong patterns of variation throughout the larval stage. Three periods were identified in four species: high initial rates of mortality; followed by a low, approximately constant rate of mortality; and finally, progressively increasing mortality after approximately 100 d. The lifetimes observed in this study suggest that the potential for long-distance dispersal may be substantially greater than previously thought. Indeed, detection of increasing mortality rates late in life suggests that energy reserves do not reach critically low levels until approximately 100 d after spawning. Conversely, increased mortality rates early in life decrease the likelihood that larvae transported away from their natal reef will survive to reach nearby reefs, and thus decrease connectivity at regional scales. These results show how variation in larval survivorship with age may help to explain the seeming paradox of high genetic structure at metapopulation scales

  8. Biosynthesis of 'essential' amino acids by scleractinian corals.

    PubMed Central

    Fitzgerald, L M; Szmant, A M

    1997-01-01

    Animals rely on their diet for amino acids that they are incapable either of synthesizing or of synthesizing in sufficient quantities to meet metabolic needs. These are the so-called 'essential amino acids'. This set of amino acids is similar among the vertebrates and many of the invertebrates. Previously, no information was available for amino acid synthesis by the most primitive invertebrates, the Cnidaria. The purpose of this study was to examine amino acid synthesis by representative cnidarians within the Order Scleractinia. Three species of zooxanthellate reef coral, Montastraea faveolata, Acropora cervicornis and Porites divaricata, and two species of non-zooxanthellate coral, Tubastrea coccinea and Astrangia poculata, were incubated with 14C-labelled glucose or with the 14C-labelled amino acids glutamic acid, lysine or valine. Radiolabel tracer was followed into protein amino acids. A total of 17 amino acids, including hydroxyproline, were distinguishable by the techniques used. Of these, only threonine was not found radiolabelled in any of the samples. We could not detect tryptophan or cysteine, nor distinguish between the amino acid pairs glutamic acid and glutamine, or aspartic acid and asparagine. Eight amino acids normally considered essential for animals were made by the five corals tested, although some of them were made only in small quantities. These eight amino acids are valine, isoleucine, leucine, tyrosine, phenylalanine histidine, methionine and lysine. The ability of cnidarians to synthesize these amino acids could be yet another indicator of a separate evolutionary history of the cnidarians from the rest of the Metazoa. PMID:9078264

  9. ICE-6G models of postglacial relative sea-level history applied to Holocene coral reef and mangrove records of the western Caribbean

    NASA Astrophysics Data System (ADS)

    Toscano, M. A.; Peltier, W. R.; Drummond, R.; Gonzalez, J.

    2012-12-01

    Fossil coral reefs and mangrove peat accumulations at western Caribbean sites along a latitudinal gradient from the Florida Keys through Belize and Panama provide dated and interpreted 8,000 year Holocene sea-level records for comparison with RSL predictions of the ICE-6G (VM5A, VM5B; L90) models of glacio-hydro-isostatic adjustment, with and without rotational feedback. These presumably passive continental margin sites provide the means to establish a N-S spatial trend in the varying influences of GIA, eustatic components of Holocene sea level, extent of forebulge collapse and influence of rotational feedback over a 20° latitudinal range. Previous ICE6G (VM5A) model-coral data comparisons for St Croix, USVI, Antigua, Martinique and Barbados (Toscano, Peltier and Drummond, 2011, QSR) along the eastern Caribbean plate and island arc illustrated the close model-data compatibility, the influence of rotational feedback acting as a significant factor in reducing misfits, and the need for high quality in situ data to confirm the extension of the proglacial forebulge into tropical latitudes. The gradient of western Caribbean continental shelf sites comprises a much more varied range of model-data relationships based on extensive combined Acropora palmata (reef crest coral) and Rhizophora mangle (microtidal mangrove) peat datasets in all cases. Starting at the northernmost region with the Florida Keys, there exist negative model misfits to the data, suggesting the possibility of a positive tectonic overprint upon expectations related to the glacial isostatic adjustment process acting alone, even though this region is normally believed to be tectonically stable. The largest multi-proxy database from Belize supports the likelihood of increasing rates of subsidence from north to south in the Belize Lagoon, which may account for numerous positive GIA model-data misfits. The southernmost site at Panama is most similar to Belize in the possible nature of tectonic influences on

  10. Cryptic changes in the genetic structure of a highly clonal coral population and the relationship with ecological performance

    NASA Astrophysics Data System (ADS)

    Williams, Dana E.; Miller, M. W.; Baums, I. B.

    2014-09-01

    Elkhorn coral , Acropora palmata, relies heavily on clonal propagation and often displays low genotypic (clonal) diversity. Populations in the Florida Keys experienced rapid declines in tissue cover between 2004 and 2006, largely due to hurricanes and disease, but remained stable from 2006 to 2010. All elkhorn colonies in 150 m2 permanent study plots were genotyped in 2006 ( n = 15 plots) and 2010 ( n = 24 plots), and plots sampled in both years were examined for changes in allelic and genotypic diversity during this period of stable ecological abundance. Overall, genetic diversity of Florida plots was low and declined further over the 4-yr period; seven of the 36 original genets and two of 67 alleles (among five microsatellite loci) were lost completely from the sampled population, and an additional 15 alleles were lost from individual reefs. In 2010, Florida plots (~19 colonies) contained an average of 2.2 ± 1.38 (mean ± SD) genets with a significant negative correlation between colony abundance and genotypic diversity. When scaled to total tissue abundance, genotypic diversity is even lower, with 43 % of genets below the size of sexual maturity. We examined the hypothesized positive relationship of local genotypic diversity with ecological performance measures. In Florida plots ( n = 15), genotypic diversity was not significantly correlated with tissue loss associated with chronic predation, nor with acute disease and storm-fragmentation events, though this relationship may be obscured by the low range of observed diversity and potential confounding with abundance. When more diverse plots in Curaçao ( n = 9) were examined, genotypic diversity was not significantly correlated with resistance during an acute storm disturbance or rate of recovery following disturbance. Cryptic loss of genetic diversity occurred in the apparently stable Florida population and confirms that stable or even increasing abundance does not necessarily indicate genetic stability.

  11. Timing and magnitude of the Caribbean mid-Holocene highstand

    NASA Astrophysics Data System (ADS)

    Ashe, E.; Khan, N.; Horton, B.; Brocard, G. Y.; Dutton, A.; Engelhart, S. E.; Kopp, R. E.; Hill, D. F.; Peltier, W. R.; Scatena, F. N.

    2015-12-01

    We present a database of published and new relative sea-level (RSL) data for the past 13 ka, which constrains the Holocene sea-level histories of the Caribbean coast of Central and South America (Florida Keys, USA to Guyana) and the Bahamas and Greater and Lesser Antilles islands. Our evaluation of mangrove peat and Acropora palmata sea-level indicators from geological investigations provides 503 sea-level index points and 242 limiting dates. We subdivide the database into 21 regions based on the availability of data, tectonic setting, and distance from the former Laurentide ice sheet. Most index points (75%) and limiting dates (90%) are <8 ka, although there is an unusual temporal distribution with the greatest amount of the data (~28%) occurring between 6-8 ka. We reassess and screen radiocarbon and U/Th ages of mangrove peat and coral data. We use the stratigraphic position (overburden thickness) of index points account for sediment compaction, and use the paleotidal model of Hill et al. (2011) to account for Holocene changes in paleotidal range. A noisy-input Gaussian process regression model calculates that the rates of RSL change were highest during the early Holocene (3-8 mm/yr) and have decreased over time (< 2 mm/yr), which is related to the reduction of ice equivalent meltwater input and collapse of the proglacial forebulge during the Holocene. The sea-level reconstructions demonstrate that RSL did not exceed the present height (0 m) during the Holocene in the majority of locations, with the exception of a small highstand (<2 m) on the northern coast of South America along the Orinoco Delta and Suriname/Guyana located furthest away from the former Laurentide Ice Sheet. The different sea-level histories are an ongoing isostatic response to deglaciation of the Laurentide Ice Sheet and suggest subsidence resulting from collapse of the proglacial forebulge reaches further south than previously considered.

  12. De Novo Assembly and Characterization of Four Anthozoan (Phylum Cnidaria) Transcriptomes.

    PubMed

    Kitchen, Sheila A; Crowder, Camerron M; Poole, Angela Z; Weis, Virginia M; Meyer, Eli

    2015-11-01

    Many nonmodel species exemplify important biological questions but lack the sequence resources required to study the genes and genomic regions underlying traits of interest. Reef-building corals are famously sensitive to rising seawater temperatures, motivating ongoing research into their stress responses and long-term prospects in a changing climate. A comprehensive understanding of these processes will require extending beyond the sequenced coral genome (Acropora digitifera) to encompass diverse coral species and related anthozoans. Toward that end, we have assembled and annotated reference transcriptomes to develop catalogs of gene sequences for three scleractinian corals (Fungia scutaria, Montastraea cavernosa, Seriatopora hystrix) and a temperate anemone (Anthopleura elegantissima). High-throughput sequencing of cDNA libraries produced ~20-30 million reads per sample, and de novo assembly of these reads produced ~75,000-110,000 transcripts from each sample with size distributions (mean ~1.4 kb, N50 ~2 kb), comparable to the distribution of gene models from the coral genome (mean ~1.7 kb, N50 ~2.2 kb). Each assembly includes matches for more than half the gene models from A. digitifera (54-67%) and many reasonably complete transcripts (~5300-6700) spanning nearly the entire gene (ortholog hit ratios ≥0.75). The catalogs of gene sequences developed in this study made it possible to identify hundreds to thousands of orthologs across diverse scleractinian species and related taxa. We used these sequences for phylogenetic inference, recovering known relationships and demonstrating superior performance over phylogenetic trees constructed using single mitochondrial loci. The resources developed in this study provide gene sequences and genetic markers for several anthozoan species. To enhance the utility of these resources for the research community, we developed searchable databases enabling researchers to rapidly recover sequences for genes of interest. Our

  13. De Novo Assembly and Characterization of Four Anthozoan (Phylum Cnidaria) Transcriptomes.

    PubMed

    Kitchen, Sheila A; Crowder, Camerron M; Poole, Angela Z; Weis, Virginia M; Meyer, Eli

    2015-09-17

    Many nonmodel species exemplify important biological questions but lack the sequence resources required to study the genes and genomic regions underlying traits of interest. Reef-building corals are famously sensitive to rising seawater temperatures, motivating ongoing research into their stress responses and long-term prospects in a changing climate. A comprehensive understanding of these processes will require extending beyond the sequenced coral genome (Acropora digitifera) to encompass diverse coral species and related anthozoans. Toward that end, we have assembled and annotated reference transcriptomes to develop catalogs of gene sequences for three scleractinian corals (Fungia scutaria, Montastraea cavernosa, Seriatopora hystrix) and a temperate anemone (Anthopleura elegantissima). High-throughput sequencing of cDNA libraries produced ~20-30 million reads per sample, and de novo assembly of these reads produced ~75,000-110,000 transcripts from each sample with size distributions (mean ~1.4 kb, N50 ~2 kb), comparable to the distribution of gene models from the coral genome (mean ~1.7 kb, N50 ~2.2 kb). Each assembly includes matches for more than half the gene models from A. digitifera (54-67%) and many reasonably complete transcripts (~5300-6700) spanning nearly the entire gene (ortholog hit ratios ≥0.75). The catalogs of gene sequences developed in this study made it possible to identify hundreds to thousands of orthologs across diverse scleractinian species and related taxa. We used these sequences for phylogenetic inference, recovering known relationships and demonstrating superior performance over phylogenetic trees constructed using single mitochondrial loci. The resources developed in this study provide gene sequences and genetic markers for several anthozoan species. To enhance the utility of these resources for the research community, we developed searchable databases enabling researchers to rapidly recover sequences for genes of interest. Our

  14. De Novo Assembly and Characterization of Four Anthozoan (Phylum Cnidaria) Transcriptomes

    PubMed Central

    Kitchen, Sheila A.; Crowder, Camerron M.; Poole, Angela Z.; Weis, Virginia M.; Meyer, Eli

    2015-01-01

    Many nonmodel species exemplify important biological questions but lack the sequence resources required to study the genes and genomic regions underlying traits of interest. Reef-building corals are famously sensitive to rising seawater temperatures, motivating ongoing research into their stress responses and long-term prospects in a changing climate. A comprehensive understanding of these processes will require extending beyond the sequenced coral genome (Acropora digitifera) to encompass diverse coral species and related anthozoans. Toward that end, we have assembled and annotated reference transcriptomes to develop catalogs of gene sequences for three scleractinian corals (Fungia scutaria, Montastraea cavernosa, Seriatopora hystrix) and a temperate anemone (Anthopleura elegantissima). High-throughput sequencing of cDNA libraries produced ∼20–30 million reads per sample, and de novo assembly of these reads produced ∼75,000–110,000 transcripts from each sample with size distributions (mean ∼1.4 kb, N50 ∼2 kb), comparable to the distribution of gene models from the coral genome (mean ∼1.7 kb, N50 ∼2.2 kb). Each assembly includes matches for more than half the gene models from A. digitifera (54–67%) and many reasonably complete transcripts (∼5300–6700) spanning nearly the entire gene (ortholog hit ratios ≥0.75). The catalogs of gene sequences developed in this study made it possible to identify hundreds to thousands of orthologs across diverse scleractinian species and related taxa. We used these sequences for phylogenetic inference, recovering known relationships and demonstrating superior performance over phylogenetic trees constructed using single mitochondrial loci. The resources developed in this study provide gene sequences and genetic markers for several anthozoan species. To enhance the utility of these resources for the research community, we developed searchable databases enabling researchers to rapidly recover sequences for genes

  15. Detailed Sea Level Record from Barbados Spanning 13,000 to 11,000 Years Before Present

    NASA Astrophysics Data System (ADS)

    Abdul, N. A.; Mortlock, R. A.; Wright, J. D.; Fairbanks, R. G.

    2013-12-01

    Th/U dated reef-crest corals (Acropora palmata) obtained from new Barbados offshore drill cores provide a local sea level reconstruction in unprecedented detail. The time interval, 13,000 to 11,000 years before present (BP), spans the well-studied Younger Dryas pollen zone, a period that has given rise to more than three decades of sensational climate interpretations and popular press. Widely described as a time when Earth's climate reverted to "glacial-like conditions" the various hypotheses that attempt to explain the "cause" of the Younger Dryas climate event have their staunch supporters as well as their critics but there remains little consensus. The Barbados sea level record for this time interval shows that sea level continued to rise during the Younger Dryas, albeit at a slower rate than prior to 13,000 or following 11,000 years BP. The decrease in the rate of sea level rise can simply be explained by the slow expansion of the Fennoscandian Ice Sheet beginning 12,800 years BP followed by its faster demise contributing to a period of rapid sea level increase known as Melt Water Pulse 1B. We calculate the ice volume history of the Fennoscandian Ice Sheet and it compares favorably to the moraine history and ice models. The Younger Dryas climate event is most often defined by the rapid shifts in atmospheric proxies measured in ice cores from Greenland. The ice core proxies shift into and out of the Younger Dryas climate event in only a few years to a few decades. Abrupt shifts in the climate state associated with the onset and termination of the Younger Dryas as revealed in Greenland Ice cores are not expressed in the smooth Barbados deglacial sea level record. We make the case that these Greenland atmospheric records mark regional atmospheric frontal shifts and changes in air mass sources over an ice sheet that largely did not participate in the deglaciation or sea level change. As proposed decades ago, the warming of the North Atlantic between 14,000 and 13

  16. 21 CFR 582.40 - Natural extractives (solvent-free) used in conjunction with spices, seasonings, and flavorings.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... source Algae, brown Laminaria spp. and Nereocystis spp. Algae, red Porphyra spp. and Rhodymenia palmata... (see algae, brown). Peach kernel (persic oil) Prunus persica Sieb. et Zucc. Peanut stearine...

  17. 21 CFR 582.40 - Natural extractives (solvent-free) used in conjunction with spices, seasonings, and flavorings.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... source Algae, brown Laminaria spp. and Nereocystis spp. Algae, red Porphyra spp. and Rhodymenia palmata... (see algae, brown). Peach kernel (persic oil) Prunus persica Sieb. et Zucc. Peanut stearine...

  18. 21 CFR 582.40 - Natural extractives (solvent-free) used in conjunction with spices, seasonings, and flavorings.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... source Algae, brown Laminaria spp. and Nereocystis spp. Algae, red Porphyra spp. and Rhodymenia palmata... (see algae, brown). Peach kernel (persic oil) Prunus persica Sieb. et Zucc. Peanut stearine...

  19. 21 CFR 582.40 - Natural extractives (solvent-free) used in conjunction with spices, seasonings, and flavorings.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... source Algae, brown Laminaria spp. and Nereocystis spp. Algae, red Porphyra spp. and Rhodymenia palmata... (see algae, brown). Peach kernel (persic oil) Prunus persica Sieb. et Zucc. Peanut stearine...

  20. 21 CFR 582.40 - Natural extractives (solvent-free) used in conjunction with spices, seasonings, and flavorings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... source Algae, brown Laminaria spp. and Nereocystis spp. Algae, red Porphyra spp. and Rhodymenia palmata... (see algae, brown). Peach kernel (persic oil) Prunus persica Sieb. et Zucc. Peanut stearine...

  1. Predatory luring behavior of odonates.

    PubMed

    Edgehouse, Michael; Brown, Christopher P

    2014-01-01

    Organisms in the order Odonata are highly predatory insects that have a wide distribution globally. To date, there has been zero evidence that odonates employ luring as a means of prey acquisition. However, in this study, we show that Aeshna palmata larvae use abdominal movements to lure larval Argia vivida, subsequently consuming the lured organism. We also present findings of a similar behavior from larval Ar. vivida in an attempt to lure larval A. palmata within striking distance. PMID:25347837

  2. A study of the interacting effects of elevated temperature and CO2 on the skeletal growth of two Caribbean coral species

    NASA Astrophysics Data System (ADS)

    Langdon, C.; Baker, A.; Jones, P.

    2011-12-01

    A study was conducted to investigate how corals may be impacted by the combination of rising temperature and declining pH. In a fully crossed experimental design two important Caribbean reef-building coral species Acropora cervicornis and Montastraea faveolata were exposed to combinations of a normal (26°C) and elevated (32°C) temperature and normal (380 ppm) and elevated (800 ppm) CO2 level. Nine colonies of each species were placed in eight tanks. Two tanks were assigned to each of the four temperature and CO2 combinations. The CO2 level was controlled by bubbling with either outside air or outside air enriched with CO2 gas to achieve the desired CO2 concentration in the tank. Corals were pre-conditioned for 39 days under 26°C and 380 ppm. The temperature and CO2 in the experimental tanks was then ramped up at a rate of 0.3°C and 30 ppm per day over a two week period. The skeletal growth of the corals was measured weekly over 62 days using an optical or laser micrometer. At the end of the high temperature and CO2 part the experiment the ability of the corals to recover from these stressful conditions was examined for 56 days. The CO2 in the high CO2 tanks was reduced to 380 ppm and the temperature in the 32°C 380 tanks was reduced to 26°C. This experiment is our second attempt to measure short term changes in skeletal growth as a function of temperature and CO2. In the first year none of the corals grew. We eventually discovered that supplemental feeding was necessary. The results of the second year's experiment are interesting but exhibit a great deal of variability. Forty-four percent of A. cervicornis colonies exhibited a decline in growth of 45% and seventy-seven percent of the M. faveolata colonies experienced a decline of 44% under 800 ppm and recovered quickly when the CO2 was lowered to 380 ppm during the recovery phase. However, the other colonies either failed to grow at all, showed no response to CO2 or seemed to grow more quickly under elevated

  3. Sensitivity of Calcification to Thermal Stress Varies among Genera of Massive Reef-Building Corals

    PubMed Central

    Carricart-Ganivet, Juan P.; Cabanillas-Terán, Nancy; Cruz-Ortega, Israel; Blanchon, Paul

    2012-01-01

    Reductions in calcification in reef-building corals occur when thermal conditions are suboptimal, but it is unclear how they vary between genera in response to the same thermal stress event. Using densitometry techniques, we investigate reductions in the calcification rate of massive Porites spp. from the Great Barrier Reef (GBR), and P. astreoides, Montastraea faveolata, and M. franksi from the Mesoamerican Barrier Reef (MBR), and correlate them to thermal stress associated with ocean warming. Results show that Porites spp. are more sensitive to increasing temperature than Montastraea, with calcification rates decreasing by 0.40 g cm−2 year−1 in Porites spp. and 0.12 g cm−2 year−1 in Montastraea spp. for each 1°C increase. Under similar warming trends, the predicted calcification rates at 2100 are close to zero in Porites spp. and reduced by 40% in Montastraea spp. However, these predictions do not account for ocean acidification. Although yearly mean aragonite saturation (Ωar) at MBR sites has recently decreased, only P. astreoides at Chinchorro showed a reduction in calcification. In corals at the other sites calcification did not change, indicating there was no widespread effect of Ωar changes on coral calcification rate in the MBR. Even in the absence of ocean acidification, differential reductions in calcification between Porites spp. and Montastraea spp. associated with warming might be expected to have significant ecological repercussions. For instance, Porites spp. invest increased calcification in extension, and under warming scenarios it may reduce their ability to compete for space. As a consequence, shifts in taxonomic composition would be expected in Indo-Pacific reefs with uncertain repercussions for biodiversity. By contrast, Montastraea spp. use their increased calcification resources to construct denser skeletons. Reductions in calcification would therefore make them more susceptible to both physical and biological breakdown, seriously

  4. Sensitivity of calcification to thermal stress varies among genera of massive reef-building corals.

    PubMed

    Carricart-Ganivet, Juan P; Cabanillas-Terán, Nancy; Cruz-Ortega, Israel; Blanchon, Paul

    2012-01-01

    Reductions in calcification in reef-building corals occur when thermal conditions are suboptimal, but it is unclear how they vary between genera in response to the same thermal stress event. Using densitometry techniques, we investigate reductions in the calcification rate of massive Porites spp. from the Great Barrier Reef (GBR), and P. astreoides, Montastraea faveolata, and M. franksi from the Mesoamerican Barrier Reef (MBR), and correlate them to thermal stress associated with ocean warming. Results show that Porites spp. are more sensitive to increasing temperature than Montastraea, with calcification rates decreasing by 0.40 g cm(-2) year(-1) in Porites spp. and 0.12 g cm(-2) year(-1) in Montastraea spp. for each 1°C increase. Under similar warming trends, the predicted calcification rates at 2100 are close to zero in Porites spp. and reduced by 40% in Montastraea spp. However, these predictions do not account for ocean acidification. Although yearly mean aragonite saturation (Ω(ar)) at MBR sites has recently decreased, only P. astreoides at Chinchorro showed a reduction in calcification. In corals at the other sites calcification did not change, indicating there was no widespread effect of Ω(ar) changes on coral calcification rate in the MBR. Even in the absence of ocean acidification, differential reductions in calcification between Porites spp. and Montastraea spp. associated with warming might be expected to have significant ecological repercussions. For instance, Porites spp. invest increased calcification in extension, and under warming scenarios it may reduce their ability to compete for space. As a consequence, shifts in taxonomic composition would be expected in Indo-Pacific reefs with uncertain repercussions for biodiversity. By contrast, Montastraea spp. use their increased calcification resources to construct denser skeletons. Reductions in calcification would therefore make them more susceptible to both physical and biological breakdown

  5. Best-fit analysis for future coral reef survivors on Bonaire: A lifeline to the reefs' future in the region

    NASA Astrophysics Data System (ADS)

    Johnson, C. C.; Elswick, E. R.; Beeker, C. D.; Kauffman, E. G.; Budziak, A. T.; Wiegand, N.

    2012-12-01

    Given the decline of Caribbean corals and increases in environmental threats and human stressors to the reef ecosystem, it is imperative to document and establish a biological and environmental baseline inventory of coral recruits and environments in which corals live. Our project investigated the association of corals and water chemistry on the leeward side of Bonaire to test for and assess the hypothesis of ocean acidification affecting one of the healthiest reefs in the Caribbean. A dry island such as Bonaire, with no major river input into the leeward side of the island, provides an ideal location for such an analyses as it yields a relatively pure ocean chemistry signal. A multi-year investigation in Bonaire National Marine Park (BNMP) focused on corals growing on mooring buoy anchors created from cement blocks and cement filled, discarded petroleum barrels. We evaluate the persistence of corals on anchors placed in BNMP in the 1960's and 1970's, taking advantage of the maximum timeline for coral recruits. Recruits initiated in the zone occupied initially by Acropora cervicornis and A. palmata, and persisted through the decline of the once dominant acroporids. Thus, our study can be taken as a natural inoculation experiment under ambient field conditions. We collected 200ml water samples at 25 sites and analyzed samples on the Atomic Absorption Spectrometer Analyst 800 and Dionex IC25 Ion Chromatograph instruments to yield elemental data for water chemistry analyses. Depth pH, temperature, salinity and turbidity were recorded per site in rainy and dry seasons over the 5-year, Nov 2007 - April 2011 study. pH measurements were taken by colorimetric and indicator strips. Biologic data collection focused on coral species identifications per site on mooring anchors but sponges, hydrozoans and algae were also noted. Our research reveals no pH changes in these shallow (12.2m) waters over the duration of the study. pH colorimetric averages were 8.0-8.5 for both April

  6. YELLOW-BLOTCH DISEASE OUTBREAK ON REEFS OF THE SAN BLAS ISLANDS, PANAMA

    EPA Science Inventory

    During the post-8th International Coral Reef Symposium field trip to the eastern Caribbean region of Panama, 3-5 July 1996, we observed an extensive outbreak of a new and significant disease of the scleractinian corals Montastraea faveolata and M. annularis. The first reported si...

  7. 76 FR 57957 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendment 11 to the Fishery...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ... Acropora corals and lobster trap line-marking requirements. The purpose of this NOI is to solicit public... to protect coral and implementing lobster trap line-marking requirements. A September 2, 2011,...

  8. Assessment of the relative contribution of asexual propagation in a population of the coral-excavating sponge Cliona delitrix from the Bahamas

    NASA Astrophysics Data System (ADS)

    Zilberberg, C.; Maldonado, M.; Solé-Cava, Am

    2006-05-01

    Cliona delitrix is a very destructive coral-excavating sponge in Caribbean coral reef systems, particularly for Montastraea species. Little is known about how these excavating sponges propagate across coral reefs. In this study a hypothesis was tested that coral breakage caused by the bioeroding activity facilitates the asexual propagation of this sponge and in turn favors the spread of the most aggressive sponge genotypes. An allozyme analysis, involving 12 loci systems of 52 sponge individuals from a total of 13 Montastraea heads, found that no two sponges possessed identical multi-locus genotypes. Contrary to the pattern expected for fragmenting species, the incidence of clonality and asexual propagation at the population level was minimal. The lack of correlation between genetic and physical distances for the studied sponges also suggests that population maintenance appears to derive from larval dispersal, with a spatial range of dispersal larger than the average distance between the coral heads (10-102 m).

  9. Coral bleaching at Little Cayman, Cayman Islands 2009

    NASA Astrophysics Data System (ADS)

    van Hooidonk, Ruben J.; Manzello, Derek P.; Moye, Jessica; Brandt, Marilyn E.; Hendee, James C.; McCoy, Croy; Manfrino, Carrie

    2012-06-01

    The global rise in sea temperature through anthropogenic climate change is affecting coral reef ecosystems through a phenomenon known as coral bleaching; that is, the whitening of corals due to the loss of the symbiotic zooxanthellae which impart corals with their characteristic vivid coloration. We describe aspects of the most prevalent episode of coral bleaching ever recorded at Little Cayman, Cayman Islands, during the fall of 2009. The most susceptible corals were found to be, in order, Siderastrea siderea, Montastraea annularis, and Montastraea faveolata, while Diplora strigosa and Agaricia spp. were less so, yet still showed considerable bleaching prevalence and severity. Those found to be least susceptible were Porites porites, Porites astreoides, and Montastraea cavernosa. These observations and other reported observations of coral bleaching, together with 29 years (1982-2010) of satellite-derived sea surface temperatures, were used to optimize bleaching predictions at this location. To do this a Degree Heating Weeks (DHW) and Peirce Skill Score (PSS) analysis was employed to calculate a local bleaching threshold above which bleaching was expected to occur. A threshold of 4.2 DHW had the highest skill, with a PSS of 0.70. The method outlined here could be applied to other regions to find the optimal bleaching threshold and improve bleaching predictions.

  10. Morphological Variation in Leaf Dissection of Rheum palmatum Complex (Polygonaceae)

    PubMed Central

    Wang, Xu-Mei; Hou, Xiao-Qi; Zhang, Yu-Qu; Li, Yan

    2014-01-01

    Aims Rheum palmatum complex comprises all taxa within section Palmata in the genus Rheum, including R. officinale, R. palmatum, R. tanguticum, R. tanguticum var. liupanshanense and R. laciniatum. The identification of the taxa in section Palmata is based primarily on the degree of leaf blade dissection and the shape of the lobes; however, difficulties in species identification may arise from their significant variation. The aim of this study is to analyze the patterns of variation in leaf blade characteristics within and among populations through population-based sampling covering the entire distribution range of R. palmatum complex. Methods Samples were taken from 2340 leaves from 780 individuals and 44 populations representing the four species, and the degree of leaf blade dissection and the shape of the lobe were measured to yield a set of quantitative data. Furthermore, those data were statistically analyzed. Important Findings The statistical analysis showed that the degree of leaf blade dissection is continuous from lobed to parted, and the shape of the lobe is also continuous from broadly triangular to lanceolate both within and between populations. We suggested that taxa in section Palmata should be considered as one species. Based on the research on the R. palmatum complex, we considered that the quantitative characteristics were greatly influenced by the environment. Therefore, it is not reliable to delimitate the species according to the continuously quantitative vegetative characteristics. PMID:25349989

  11. Holocene key coral species in the Northwest Pacific: indicators of reef formation and reef ecosystem responses to global climate change and anthropogenic stresses in the near future

    NASA Astrophysics Data System (ADS)

    Hongo, Chuki

    2012-03-01

    The geological record of key coral species that contribute to reef formation and maintenance of reef ecosystems is important for understanding the ecosystem response to global-scale climate change and anthropogenic stresses in the near future. Future responses can be predicted from accumulated data on Holocene reef species identified in drillcore and from data on raised reef terraces. The present study analyzes a dataset based on 27 drillcores, raised reef terraces, and 134 radiocarbon and U-Th ages from reefs of the Northwest Pacific, with the aim of examining the role of key coral species in reef growth and maintenance for reef ecosystem during Holocene sea-level change. The results indicate a latitudinal change in key coral species: arborescent Acropora (Acropora intermedia and Acropora muricata) was the dominant reef builder at reef crests in the tropics, whereas Porites (Porites australiensis, Porites lutea, and Porites lobata) was the dominant contributor to reef growth in the subtropics between 10,000 and 7000 cal. years BP (when the rate of sea-level rise was 10 m/ka). Acropora digitifera, Acropora hyacinthus, Acropora robusta/A. abrotanoides, Isopora palifera, Favia stelligera, and Goniastrea retiformis from the corymbose and tabular Acropora facies were the main key coral species at reef crests between 7000 and 5000 cal. years BP (when the rate of sea-level rise was 5 m/ka) and during the following period of stable sea-level. Massive Porites (P. australiensis, P. lutea, and P. lobata) contributed to reef growth in shallow lagoons during the period of stable sea level. Key coral species from the corymbose and tabular Acropora facies have the potential to build reefs and maintain ecosystems in the near future under a global sea-level rise of 2-6 m/ka, as do key coral species from the arborescent Acropora facies and massive Porites facies, which show vigorous growth and are tolerant to relatively deep-water, low-energy environments. However, these species

  12. Probing a Coral Genome for Components of the Photoprotective Scytonemin Biosynthetic Pathway and the 2-Aminoethylphosphonate Pathway

    PubMed Central

    Shoguchi, Eiichi; Tanaka, Makiko; Takeuchi, Takeshi; Shinzato, Chuya; Satoh, Nori

    2013-01-01

    Genome sequences of the reef-building coral, Acropora digitifera, have been decoded. Acropora inhabits an environment with intense ultraviolet exposure and hosts the photosynthetic endosymbiont, Symbiodinium. Acropora homologs of all four genes necessary for biosynthesis of the photoprotective cyanobacterial compound, shinorine, are present. Among metazoans, these genes are found only in anthozoans. To gain further evolutionary insights into biosynthesis of photoprotective compounds and associated coral proteins, we surveyed the Acropora genome for 18 clustered genes involved in cyanobacterial synthesis of the anti-UV compound, scytonemin, even though it had not previously been detected in corals. We identified candidates for only 6 of the 18 genes, including tyrP, scyA, and scyB. Therefore, it does not appear that Acropora digitifera can synthesize scytonemin independently. On the other hand, molecular phylogenetic analysis showed that one tyrosinase gene is an ortholog of vertebrate tyrosinase genes and that the coral homologs, scyA and scyB, are similar to bacterial metabolic genes, phosphonopyruvate (ppyr) decarboxylase and glutamate dehydrogenase (GDH), respectively. Further genomic searches for ppyr gene-related biosynthetic components indicate that the coral possesses a metabolic pathway similar to the bacterial 2-aminoethylphosphonate (AEP) biosynthetic pathway. The results suggest that de novo synthesis of carbon-phosphorus compounds is performed in corals. PMID:23434798

  13. Some Physical, Chemical, and Biological Parameters of Samples of Scleractinium Coral Aquaculture Skeleton Used for Reconstruction/Engineering of the Bone Tissue.

    PubMed

    Popov, A A; Sergeeva, N S; Britaev, T A; Komlev, V S; Sviridova, I K; Kirsanova, V A; Akhmedova, S A; Dgebuadze, P Yu; Teterina, A Yu; Kuvshinova, E A; Schanskii, Ya D

    2015-08-01

    Physical and chemical (phase and chemical composition, dynamics of resorption, and strength properties), and biological (cytological compatibility and scaffold properties of the surface) properties of samples of scleractinium coral skeletons from aquacultures of three types and corresponding samples of natural coral skeletons (Pocillopora verrucosa, Acropora formosa, and Acropora nobilis) were studied. Samples of scleractinium coral aquaculture skeleton of A. nobilis, A. formosa, and P. verrucosa met the requirements (all study parameters) to materials for osteoplasty and 3D-scaffolds for engineering of bone tissue.

  14. Food selection of a corallivorous butterflyfish Chaetodon austriacus in the Red Sea, with particular emphasis on size and fish symbionts of corals.

    PubMed

    Niedermüller, S K; Schiemer, L S; Herler, J

    2009-10-01

    The exquisite butterflyfish Chaetodon austriacus feeds mainly on Acropora, Pocillopora, Montipora and Stylophora in the northern Red Sea. Large colonies of Acropora are preferred over smaller colonies and other coral genera, whereas avoidance is indicated for corals that are occupied by certain coral-associated gobiid fishes of the genus Gobiodon. It is suggested that, apart from coral identity, colony size and potential repellent effects of particular coral symbionts are both important sources of variation in the food selectivity of corallivorous chaetodotids. PMID:20738627

  15. Spatial Patterns of Parrotfish Corallivory in the Caribbean: The Importance of Coral Taxa, Density and Size

    PubMed Central

    Roff, George; Ledlie, Mary H.; Ortiz, Juan C.; Mumby, Peter J.

    2011-01-01

    The past few decades have seen an increase in the frequency and intensity of disturbance on coral reefs, resulting in shifts in size and composition of coral populations. These changes have lead to a renewed focus on processes that influence demographic rates in corals, such as corallivory. While previous research indicates selective corallivory among coral taxa, the importance of coral size and the density of coral colonies in influencing corallivory are unknown. We surveyed the size, taxonomy and number of bites by parrotfish per colony of corals and the abundance of three main corallivorous parrotfish (Sparisoma viride, Sparisoma aurofrenatum, Scarus vetula) at multiple spatial scales (reefs within islands: 1–100 km, and between islands: >100 km) within the Bahamas Archipelago. We used a linear mixed model to determine the influence of coral taxa, colony size, colony density, and parrotfish abundance on the intensity of corallivory (bites per m2 of coral tissue). While the effect of colony density was significant in determining the intensity of corallivory, we found no significant influence of colony size or parrotfish abundance (density, biomass or community structure). Parrotfish bites were most frequently observed on the dominant species of reef building corals (Montastraea annularis, Montastraea faveolata and Porites astreoides), yet our results indicate that when the confounding effects of colony density and size were removed, selective corallivory existed only for the less dominant Porites porites. As changes in disturbance regimes result in the decline of dominant frame-work building corals such as Montastraea spp., the projected success of P. porites on Caribbean reefs through high reproductive output, resistance to disease and rapid growth rates may be attenuated through selective corallivory by parrotfish. PMID:22216184

  16. Discovery of symbiotic nitrogen-fixing cyanobacteria in corals.

    PubMed

    Lesser, Michael P; Mazel, Charles H; Gorbunov, Maxim Y; Falkowski, Paul G

    2004-08-13

    Colonies of the Caribbean coral Montastraea cavernosa exhibit a solar-stimulated orange-red fluorescence that is spectrally similar to a variety of fluorescent proteins expressed by corals. The source of this fluorescence is phycoerythrin in unicellular, nonheterocystis, symbiotic cyanobacteria within the host cells of the coral. The cyanobacteria coexist with the symbiotic dinoflagellates (zooxanthellae) of the coral and express the nitrogen-fixing enzyme nitrogenase. The presence of this prokaryotic symbiont in a nitrogen-limited zooxanthellate coral suggests that nitrogen fixation may be an important source of this limiting element for the symbiotic association.

  17. 77 FR 25116 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-27

    ... protect threatened species of corals. DATES: Written comments must be received on or before June 26, 2012... prudent measures (RPMs), including creation of new or expansion of existing closed areas to protect coral... threatened Acropora species of coral and to require markings on lobster trap lines unique to the...

  18. 78 FR 57835 - Endangered and Threatened Wildlife and Plants; Notice of 6-Month Extension of the Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ... Federal Register (77 FR 73219) in response to a petition from the Center of Biological Diversity to list... Coral as Threatened or Endangered Under the Endangered Species Act and Reclassify Acropora cervicornis... corals (59 in the Pacific and seven in the Caribbean) and to re- classify two species already...

  19. Effects of disturbance on coral communities: bleaching in Moorea, French Polynesia

    NASA Astrophysics Data System (ADS)

    Gleason, M. G.

    1993-11-01

    This study examines patterns of susceptibility and short-term recovery of corals from bleaching. A mass coral bleaching event began in March, 1991 on reefs in Moorea, French Polynesia and affected corals on the shallow barrier reef and to >20 m depth on the outer forereef slope. There were significant differences in the effect of the bleaching among common coral genera, with Acropora, Montastrea, Montipora, and Pocillopora more affected than Porites, Pavona, leptastrea or Millepora. Individual colonies of the common species of Acropora and Pocillopora were marked and their fate assessed on a subsequent survey in August, 1991 to determine rates of recovery and mortality. Ninety-six percent of Acropora spp. showed some degree of bleaching compared to 76% of Pocillopora spp. From March to August mortality of bleached colonies of Pocillopora was 17%, 38% recovered completely, and many suffered some partial mortality of the tissue. In contrast, 63% of the Acropora spp. died, and about 10% recovered completely. Generally, those colonies with less than 50% of the colony area affected by the bleaching recovered at a higher rate than did those with more severe bleaching. Changes in community composition four months after the event began included a significant decrease only in crustose algae and an increase in cover of filamentous algae, much of which occupied plate-like and branching corals that had died in the bleaching event. Total coral cover and cover of susceptible coral genera had declined, but not significantly, after the event.

  20. CHARACTERIZATION OF THE BACTERIUM SUSPECTED IN THE INCIDENCE OF WHITE BAND DISEASE

    EPA Science Inventory

    The common staghorn coral, Acropora cervicomis, has been critically impacted in the U.S. Virgin Islands by a condition described as white band disease, a malady accompanied by the presence of abundant finely granular ovoid basophilic bodies within degenerating tissues of this sto...

  1. Coral recovery in the central Maldives archipelago since the last major mass-bleaching, in 1998

    PubMed Central

    Pisapia, C.; Burn, D.; Yoosuf, R.; Najeeb, A.; Anderson, K. D.; Pratchett, M. S.

    2016-01-01

    Increasing frequency and severity of disturbances is causing global degradation of coral reef ecosystems. This study examined temporal changes in live coral cover and coral composition in the central Maldives from 1997 to 2016, encompassing two bleaching events, a tsunami, and an outbreak of Acanthaster planci. We also examined the contemporary size structure for five dominant coral taxa (tabular Acropora, Acropora muricata, Acropora humilis, Pocillopora spp, and massive Porites). Total coral cover increased throughout the study period, with marked increases following the 1998 mass-bleaching. The relative abundance of key genera has changed through time, where Acropora and Pocillopora (which are highly susceptible to bleaching) were under-represented following 1998 mass-bleaching but increased until outbreaks of A. planci in 2015. The contemporary size-structure for all coral taxa was dominated by larger colonies with peaked distributions suggesting that recent disturbances had a disproportionate impact on smaller colonies, or that recruitment is currently limited. This may suggest that coral resilience has been compromised by recent disturbances, and further bleaching (expected in 2016) could lead to highly protracted recovery times. We showed that Maldivian reefs recovered following the 1998 mass-bleaching event, but it took up to a decade, and ongoing disturbances may be eroding reef resilience. PMID:27694823

  2. [Low water temperature tolerance and responding mode of scleractinian corals in Sanya Bay].

    PubMed

    Li, Shu; Yu, Ke-fu; Shi, Qi; Chen, Tian-ran; Zhao, Mei-xia

    2009-09-01

    In an experimental temperature-regulated mesocosm, the low water temperature tolerance of five dominant scleractinian coral species Pavona decussate, Acropora pulchra, Acropora florida, Acropora valida, and Porites lutea in Sanya Bay was investigated, and their responding modes to the cold water stress were analyzed. The tolerance of test corals to low water temperature was closely related to their morphologies, with the branching corals being the most vulnerable to bleaching and death by separating the symbiotic polyps from their skeletons. The lethal low water temperature for branching Acropora corals was 14 degrees C lasting for 3 days, and that for foliose P. decussate was 12 degrees C lasting for 10 days. Massive P. lutea corals responded to low water temperature by forming mucus membrane, which helped to prevent the further losing of symbiotic algae. The corals showing strong tolerance to high water temperature also had strong tolerance to low water temperature, and had similar responding modes to both high and low water temperature, i.e., the corals didn't extend their tentacle first, followed by the continuous release of mucus and the discharge of symbiotic zooxanthellae, and finally, bleached and died.

  3. The Anti-Inflammatory Effect of Algae-Derived Lipid Extracts on Lipopolysaccharide (LPS)-Stimulated Human THP-1 Macrophages.

    PubMed

    Robertson, Ruairi C; Guihéneuf, Freddy; Bahar, Bojlul; Schmid, Matthias; Stengel, Dagmar B; Fitzgerald, Gerald F; Ross, R Paul; Stanton, Catherine

    2015-08-01

    Algae contain a number of anti-inflammatory bioactive compounds such as omega-3 polyunsaturated fatty acids (n-3 PUFA) and chlorophyll a, hence as dietary ingredients, their extracts may be effective in chronic inflammation-linked metabolic diseases such as cardiovascular disease. In this study, anti-inflammatory potential of lipid extracts from three red seaweeds (Porphyra dioica, Palmaria palmata and Chondrus crispus) and one microalga (Pavlova lutheri) were assessed in lipopolysaccharide (LPS)-stimulated human THP-1 macrophages. Extracts contained 34%-42% total fatty acids as n-3 PUFA and 5%-7% crude extract as pigments, including chlorophyll a, β-carotene and fucoxanthin. Pretreatment of the THP-1 cells with lipid extract from P. palmata inhibited production of the pro-inflammatory cytokines interleukin (IL)-6 (p < 0.05) and IL-8 (p < 0.05) while that of P. lutheri inhibited IL-6 (p < 0.01) production. Quantitative gene expression analysis of a panel of 92 genes linked to inflammatory signaling pathway revealed down-regulation of the expression of 14 pro-inflammatory genes (TLR1, TLR2, TLR4, TLR8, TRAF5, TRAF6, TNFSF18, IL6R, IL23, CCR1, CCR4, CCL17, STAT3, MAP3K1) by the lipid extracts. The lipid extracts effectively inhibited the LPS-induced pro-inflammatory signaling pathways mediated via toll-like receptors, chemokines and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling molecules. These results suggest that lipid extracts from P. lutheri, P. palmata, P. dioica and C. crispus can inhibit LPS-induced inflammatory pathways in human macrophages. Therefore, algal lipid extracts should be further explored as anti-inflammatory ingredients for chronic inflammation-linked metabolic diseases. PMID:26308008

  4. The Anti-Inflammatory Effect of Algae-Derived Lipid Extracts on Lipopolysaccharide (LPS)-Stimulated Human THP-1 Macrophages

    PubMed Central

    Robertson, Ruairi C.; Guihéneuf, Freddy; Bahar, Bojlul; Schmid, Matthias; Stengel, Dagmar B.; Fitzgerald, Gerald F.; Ross, R. Paul; Stanton, Catherine

    2015-01-01

    Algae contain a number of anti-inflammatory bioactive compounds such as omega-3 polyunsaturated fatty acids (n-3 PUFA) and chlorophyll a, hence as dietary ingredients, their extracts may be effective in chronic inflammation-linked metabolic diseases such as cardiovascular disease. In this study, anti-inflammatory potential of lipid extracts from three red seaweeds (Porphyra dioica, Palmaria palmata and Chondrus crispus) and one microalga (Pavlova lutheri) were assessed in lipopolysaccharide (LPS)-stimulated human THP-1 macrophages. Extracts contained 34%–42% total fatty acids as n-3 PUFA and 5%–7% crude extract as pigments, including chlorophyll a, β-carotene and fucoxanthin. Pretreatment of the THP-1 cells with lipid extract from P. palmata inhibited production of the pro-inflammatory cytokines interleukin (IL)-6 (p < 0.05) and IL-8 (p < 0.05) while that of P. lutheri inhibited IL-6 (p < 0.01) production. Quantitative gene expression analysis of a panel of 92 genes linked to inflammatory signaling pathway revealed down-regulation of the expression of 14 pro-inflammatory genes (TLR1, TLR2, TLR4, TLR8, TRAF5, TRAF6, TNFSF18, IL6R, IL23, CCR1, CCR4, CCL17, STAT3, MAP3K1) by the lipid extracts. The lipid extracts effectively inhibited the LPS-induced pro-inflammatory signaling pathways mediated via toll-like receptors, chemokines and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling molecules. These results suggest that lipid extracts from P. lutheri, P. palmata, P. dioica and C. crispus can inhibit LPS-induced inflammatory pathways in human macrophages. Therefore, algal lipid extracts should be further explored as anti-inflammatory ingredients for chronic inflammation-linked metabolic diseases. PMID:26308008

  5. Contrasting evolutionary patterns in two reef-corals and their possible relationship to life history traits

    SciTech Connect

    Foster, A.B.

    1985-01-01

    Multivariate statistical analyses have been used to redefine species within two genera of reef-corals (Porites and Montastraea) and to trace their evolutionary patterns through a continuous sequence from late Miocene to early Pliocene time. The material studied consists of populations sampled at regular intervals through four stratigraphic sections in the northern Dominican Republic. The results show that species in the first genus (Porites) have relatively short durations, morphologic stability, and narrow spatial distributions. Their overall evolutionary history is characterized by short periods of radiation and widespread extinction, separated by longer periods of stasis. In contrast, species in the second genus (Montastraea) exhibit various different durations and distributions and directional morphologic trends. These differences in patterns may be related to the dissimilar life histories of the two genera. Patterns in the first genus appear more common in organisms having high larval recruitment, high mortality, high genetic variation, and less morphologic distance between species. Patterns in the second genus occur more frequently in slower growing, phenotypically plastic organisms experiencing less recruitment and mortality and showing more morphologic distance between species.

  6. Properties of polysaccharides in several seaweeds from Atlantic Canada and their potential anti-influenza viral activities

    NASA Astrophysics Data System (ADS)

    Jiao, Guangling; Yu, Guangli; Wang, Wei; Zhao, Xiaoliang; Zhang, Junzeng; Ewart, Stephen H.

    2012-06-01

    To explore the polysaccharides from selected seaweeds of Atlantic Canada and to evaluate their potential anti-influenza virus activities, polysaccharides were isolated from several Atlantic Canadian seaweeds, including three red algae ( Polysiphonia lanosa, Furcellaria lumbricalis, and Palmaria palmata), two brown algae ( Ascophyllum nodosum and Fucus vesiculosus), and one green alga ( Ulva lactuca) by sequential extraction with cold water, hot water, and alkali solutions. These polysaccharides were analyzed for monosaccharide composition and other general chemical properties, and they were evaluated for anti-influenza virus activities. Total sugar contents in these polysaccharides ranged from 15.4% (in U. lactuca) to 91.4% (in F. lumbricalis); sulfation level was as high as 17.6% in a polysaccharide from U. lactuca, whereas it could not be detected in an alikali-extract from P. palmaria. For polysaccharides from red seaweeds, the main sugar units were sulfated galactans (agar or carrageenan) for P. lanosa, F. lumbricalis, and xylans for P. palmata. In brown seaweeds, the polysaccharides largely contained sulfated fucans, whereas the polysaccharides in green seaweed were mainly composed of heteroglycuronans. Screening for antiviral activity against influenza A/PR/8/34 (H1N1) virus revealed that brown algal polysaccharides were particularly effective. Seaweeds from Atlantic Canada are a good source of marine polysaccharides with potential antiviral properties.

  7. Quantitative analysis of biomarker rutin in different species of genus Ficus by validated NP and RP-HPTLC methods.

    PubMed

    AlAjmi, Mohamed Fahad; Alam, Perwez; Siddiqui, Nasir Ali; Basudan, Omer Ahmed; Hussain, Afzal

    2015-11-01

    Biomarker rutin was analyzed in methanol extracts of leaves of five different species of genus Ficus (Ficus carica, Ficus nitida, Ficus ingens, Ficus palmata and Ficus vasta) by NP-HPTLC (Method I) and RP- HPTLC methods (Method II). The development and validation for method I was carried out with silica gel 60F254 plates using EA: GAA: FA: H2O (10:1:1:2.5, v/v/v/v) as developing system. Method II was carried out on silica gel 60F254 RP-18 plates using mobile phase ACN: H2O (4:6 v/v). Both analyses were scanned at 305 nm and were found to give well resolved peak of rutin at Rf0.28±0.01 and 0.68±0.03 for Method I and Method II, respectively. The percentage of rutin was found to be 0.51% & 0.66% in F. ingens, 0.24% & 0.54% in F. palmata and 0.14% & 0.17% in F. vasta by Method I & Method II, respectively. Method II (RP-HPTLC) was found to be more accurate, precise and sensitive than Method I. Method II can be used as an important tool for standardization and quality control of bulk drugs and in-process formulations of rutin. PMID:26687740

  8. Evaluation of the contamination of marine algae (seaweed) from the St. Lawrence River and likely to be consumed by humans

    SciTech Connect

    Phaneuf, D.; Cote, I.; Dumas, P.; Ferron, L.A.; LeBlanc, A.

    1999-02-01

    The goal of the study was to assess the contamination of marine algae (seaweeds) growing in the St. Lawrence River estuary and Gulf of St. Lawrence and to evaluate the risks to human health from the consumption of these algae. Algae were collected by hand at low tide. A total of 10 sites on the north and south shores of the St. Lawrence as well as in Baie des Chaleurs were sampled. The most frequently collected species of algae were Fucus vesiculosus, Ascophyllum nodosum, Laminaria Longicruris, Palmaria palmata, Ulva lactuca, and Fucus distichus. Alga samples were analyzed for metals iodine, and organochlorines. A risk assessment was performed using risk factors. In general, concentrations in St. Lawrence algae were not very high. Consequently, health risks associated with these compounds in St. Lawrence algae were very low. Iodine concentration, on the other hand, could be of concern with regard to human health. Regular consumption of algae, especially of Laminaria sp., could result in levels of iodine sufficient to cause thyroid problems. For regular consumers, it would be preferable to choose species with low iodine concentrations, such as U. lactuca and P. palmata, in order to prevent potential problems. Furthermore, it would also be important to assess whether preparation for consumption or cooking affects the iodine content of algae. Algae consumption may also have beneficial health effects. Scientific literature has shown that it is a good source of fiber and vitamins, especially vitamin B{sub 12}.

  9. Estimating Sustainable Live-Coral Harvest at Kamiali Wildlife Management Area, Papua New Guinea

    PubMed Central

    Longenecker, Ken; Bolick, Holly; Langston, Ross

    2015-01-01

    Live coral is harvested throughout the Indo-West Pacific to make lime, used in the consumption of the world’s fourth-most consumed drug, betel nut. Coral harvesting is an environmental concern; however, because lime-making is one of the few sources of income in some areas of Papua New Guinea (PNG), the practice is unlikely to stop. To better manage coral harvest, we used standard fishery-yield methods to generate sustainable-harvest guidelines for corymbose Acropora species found on the reef flat and crest at Lababia, PNG. We constructed a yield curve (weight-specific net annual-dry-weight production) by: 1) describing the allometric relationship between colony size and dry weight, and using that relationship to estimate the dry weight of Acropora colonies in situ; 2) estimating annual growth of Acropora colonies by estimating in situ, and describing the relationship between, colony dry weight at the beginning and end of one year; and 3) conducting belt-transect surveys to describe weight-frequencies and ultimately to predict annual weight change per square meter for each weight class. Reef habitat covers a total 2,467,550 m2 at Lababia and produces an estimated 248,397 kg/y (dry weight) of corymbose Acropora, of which 203,897 kg is produced on the reef flat/crest. We conservatively estimate that 30,706.6 kg of whole, dry, corymbose, Acropora can be sustainably harvested from the reef flat/crest habitat each year provided each culled colony weighs at least 1805 g when dry (or is at least 46 cm along its major axis). Artisanal lime-makers convert 24.8% of whole-colony weight into marketable lime, thus we estimate 7615.2 g of lime can be sustainably produced annually from corymbose Acropora. This value incorporates several safety margins, and should lead to proper management of live coral harvest. Importantly, the guideline recognizes village rights to exploit its marine resources, is consistent with village needs for income, and balances an equally strong village

  10. Staghorn tempestites in the Florida Keys

    USGS Publications Warehouse

    Shinn, E.A.; Reich, C.D.; Hickey, T.D.; Lidz, B.H.

    2003-01-01

    Thirty-one samples of transported Holocene Acropora cervicornis "sticks" sampled from carbonate sand tempestite accumulations at 19 sites along a 180-km-long stretch of the Florida reef tract were dated using the radiocarbon (14C) method. The "modern fossils" collected from just a few centimeters below the surface ranged in age from 0.5 to 6.4 ka. The majority lived between 3.5 and 5.5 ka. The time of transport and deposition is not known. There were no A. cervicornis samples centered around 4.5 ka. Acropora cervicornis is living on many Florida reefs, but the youngest tempestite sample was 500 years old. Two 500-year-long gaps in dated staghorn suggest that the documented decline in living A. cervicornis over the past 25 years may not be without precedent.

  11. Coral choreography

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Viewers clicking onto the Waikiki Aquarium's “Coral Research Cam” any time during daylight hours in Hawaii can catch the latest action of three species of living corals (Acropora sp., Acropora elseyi,and Montipora digitata) and the yellow tang and blue tang fish swimming amongst them in an outdoor aquarium.Waikiki Aquarium Director Bruce Carlson says the camera is part of a new exhibit, “Corals Are Alive!,” which encourages people to view living corals close-up at the aquarium or via the Internet, in order to gain a better appreciation of the corals. “Hopefully through education and awareness, people will be more interested and willing to help with conservation efforts to preserve coral reefs,” says Carlson.

  12. Patterns of recruitment and microhabitat associations for three predatory coral reef fishes on the southern Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    Wen, C. K. C.; Pratchett, M. S.; Almany, G. R.; Jones, G. P.

    2013-06-01

    This study examined recruitment patterns and microhabitat associations for three carnivorous fishes, Plectropomus maculatus, Lutjanus carponotatus and Epinephelus quoyanus, at the Keppel Islands, southern Great Barrier Reef, Australia. Habitat selectivity was highest for recruits that were found mostly with corymbose Acropora, predominantly on patches of live coral located over loose substrates (sand). Adults were more commonly associated with tabular Acropora. The proportion of P. maculatus (72 %) found with live corals was higher than for L. carponotatus (68 %) and E. quoyanus (44 %). Densities of recruits were highly variable among locations, but this was only partly related to availability of preferred microhabitats. Our findings demonstrate that at least some carnivorous reef fishes, especially during early life-history stages, strongly associate with live corals. Such species will be highly sensitive to increasing degradation of coral reef habitats.

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

    PubMed

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

    2016-04-01

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

  14. High precision u/th dating of first Polynesian settlement.

    PubMed

    Burley, David; Weisler, Marshall I; Zhao, Jian-xin

    2012-01-01

    Previous studies document Nukuleka in the Kingdom of Tonga as a founder colony for first settlement of Polynesia by Lapita peoples. A limited number of radiocarbon dates are one line of evidence supporting this claim, but they cannot precisely establish when this event occurred, nor can they afford a detailed chronology for sequent occupation. High precision U/Th dates of Acropora coral files (abraders) from Nukuleka give unprecedented resolution, identifying the founder event by 2838±8 BP and documenting site development over the ensuing 250 years. The potential for dating error due to post depositional diagenetic alteration of ancient corals at Nukuleka also is addressed through sample preparation protocols and paired dates on spatially separated samples for individual specimens. Acropora coral files are widely distributed in Lapita sites across Oceania. U/Th dating of these artifacts provides unparalleled opportunities for greater precision and insight into the speed and timing of this final chapter in human settlement of the globe.

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

    PubMed Central

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

    2016-01-01

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

  16. Past corals and recent reefs in Indonesia

    NASA Astrophysics Data System (ADS)

    Boekschoten, G. J.; Best, Maya Borel; Oosterbaan, A.; Molenkamp, F. M.

    During the Snellius-II Expedition Lower Pilocene coral material was collected near Salayer, and Quaternary reefs were sampled on Ambon and Sumba. Coral collections from the Pliocene of Nias were also available for study. This new material is presented together with earlier data. Preservation potentials of different coral growth forms are reviewed. The absence of Acropora and Montipora from Quaternary coral faunae is striking. This is interpreted with the model of POTTS (1983), on the disturbance by Pleistocene sea level fluctuations in the reef coral fauna. Diversification within both genera is apparently very recent, which may explain their complex taxonomy. Given the dominant role of Acropora and Montipora in many present day Indonesian reefs, these are better described as transitional assemblages of corals than as established coral communities.

  17. Phylogenetic relationships in the coral family acroporidae, reassessed by inference from mitochondrial genes.

    PubMed

    Fukami, H; Omori, M; Hatta, M

    2000-07-01

    Phylogenetic relationships within the dominant reef coral family Acroporidae were inferred from the mitochondrial genes cytochrome b and ATPase 6. The rate of nucleotide substitution in the genes gave proper resolution to deduce genetic relationships between the genera in this family. The molecular phylogeny divided this family into three major lineages: the genera Astreopora, Montipora and Acropora. The genus Anacropora was included in the same clade as the genus Montipora, suggesting its recent speciation from Montipora. The subgenus Isopora was significantly distant from the subgenus Acropora. Taken together with morphological and reproductive differences, we propose that these two subgenera be classified as independent genera. The divergence times deduced from the genetic distances were consistent with the fossil record for the major genera. The results also suggest that the extant reef corals speciated and expanded very recently, probably after the Miocene, from single lineage which survived repeated extinction by climate changes during the Cenozoic era. PMID:18517306

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

    PubMed

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

    2012-10-01

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

  19. High CO2 enhances the competitive strength of seaweeds over corals.

    PubMed

    Diaz-Pulido, Guillermo; Gouezo, Marine; Tilbrook, Bronte; Dove, Sophie; Anthony, Kenneth R N

    2011-02-01

    Space competition between corals and seaweeds is an important ecological process underlying coral-reef dynamics. Processes promoting seaweed growth and survival, such as herbivore overfishing and eutrophication, can lead to local reef degradation. Here, we present the case that increasing concentrations of atmospheric CO(2) may be an additional process driving a shift from corals to seaweeds on reefs. Coral (Acropora intermedia) mortality in contact with a common coral-reef seaweed (Lobophora papenfussii) increased two- to threefold between background CO(2) (400 ppm) and highest level projected for late 21st century (1140 ppm). The strong interaction between CO(2) and seaweeds on coral mortality was most likely attributable to a chemical competitive mechanism, as control corals with algal mimics showed no mortality. Our results suggest that coral (Acropora) reefs may become increasingly susceptible to seaweed proliferation under ocean acidification, and processes regulating algal abundance (e.g. herbivory) will play an increasingly important role in maintaining coral abundance.

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

    PubMed

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

    2016-04-01

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

  1. Corals chemically cue mutualistic fishes to remove competing seaweeds.

    PubMed

    Dixson, Danielle L; Hay, Mark E

    2012-11-01

    Corals in the genus Acropora generate much of the structural complexity upon which coral reefs depend, but they are susceptible to damage from toxic seaweeds. Acropora nasuta minimizes this damage by chemically cuing symbiotic goby fishes (Gobiodon histrio or Paragobiodon echinocephalus) to remove the toxic seaweed Chlorodesmis fastigiata. Within minutes of seaweed contact, or contact from only seaweed chemical extract, the coral releases an odor that recruits gobies to trim the seaweed and dramatically reduce coral damage that would otherwise occur. In turn, chemically defended gobies become more toxic after consumption of this noxious alga. Mutualistic gobies and corals appear to represent a marine parallel to terrestrial ant-plants, in that the host provides shelter and food in return for protection from natural enemies.

  2. Does use of tropical beaches by tourists and island residents result in damage to fringing coral reefs? A case study in Moorea French Polynesia.

    PubMed

    Juhasz, Allison; Ho, Ellen; Bender, Erika; Fong, Peggy

    2010-12-01

    Although coral reefs worldwide are subject to increasing global threats, humans also impact coral reefs directly through localized activities such as snorkeling, kayaking and fishing. We investigated five sites on the northern shore of Moorea, French Polynesia, and quantified the number of visitors on the beach and in shallow water. In field surveys, we measured total coral cover and colony sizes of two common genera, Porites and Acropora, a massive and branching morphology, respectively. One site, which hosted over an order of magnitude more people than the other four, had significantly less total coral cover and supported very little branching Acropora. In addition, size frequency distributions of both the branching and massive genera were skewed toward smaller colony sizes at the high use site. Our results demonstrated that the use of tropical beaches may result in less coral cover, with branching colonies rare and small.

  3. Species-specific responses of corals to bleaching events on anthropogenically turbid reefs on Okinawa Island, Japan, over a 15-year period (1995-2009).

    PubMed

    Hongo, Chuki; Yamano, Hiroya

    2013-01-01

    Coral bleaching, triggered by elevated sea-surface temperatures (SSTs) has caused a decline in coral cover and changes in the abundances of corals on reefs worldwide. Coral decline can be exacerbated by the effects of local stressors like turbidity, yet some reefs with a natural history of turbidity can support healthy and resilient coral communities. However, little is known about responses of coral communities to bleaching events on anthropogenically turbid reefs as a result of recent (post World War II) terrestrial runoff. Analysis of region-scale coral cover and species abundance at 17-20 sites on the turbid reefs of Okinawa Island (total of 79 species, 30 genera, and 13 families) from 1995 to 2009 indicates that coral cover decreased drastically, from 24.4% to 7.5% (1.1%/year), subsequent to bleaching events in 1998 and 2001. This dramatic decrease in coral cover corresponded to the demise of Acropora species (e.g., A. digitifera) by 2009, when Acropora had mostly disappeared from turbid reefs on Okinawa Island. In contrast, Merulinidae species (e.g., Dipsastraea pallida/speciosa/favus) and Porites species (e.g., P. lutea/australiensis), which are characterized by tolerance to thermal stress, survived on turbid reefs of Okinawa Island throughout the period. Our results suggest that high turbidity, influenced by recent terrestrial runoff, could have caused a reduction in resilience of Acropora species to severe thermal stress events, because the corals could not have adapted to a relatively recent decline in water quality. The coral reef ecosystems of Okinawa Island will be severely impoverished if Acropora species fail to recover.

  4. The Role of Maternal Nutrition on Oocyte Size and Quality, with Respect to Early Larval Development in The Coral-Eating Starfish, Acanthaster planci

    PubMed Central

    Pratchett, Morgan S.; Kerr, Alexander M.; Rivera-Posada, Jairo A.

    2016-01-01

    Variation in local environmental conditions can have pronounced effects on the population structure and dynamics of marine organisms. Previous studies on crown-of-thorns starfish, Acanthaster planci, have primarily focused on effects of water quality and nutrient availability on larval growth and survival, while the role of maternal nutrition on reproduction and larval development has been overlooked. To examine the effects of maternal nutrition on oocyte size and early larval development in A. planci, we pre-conditioned females for 60 days on alternative diets of preferred coral prey (Acropora abrotanoides) versus non-preferred coral prey (Porites rus) and compared resulting gametes and progeny to those produced by females that were starved over the same period. Females fed ad libitum with Acropora increased in weight, produced heavier gonads and produced larger oocytes compared to Porites-fed and starved females. Fed starfish (regardless of whether it was Acropora or Porites) produced bigger larvae with larger stomachs and had a higher frequency of normal larvae that reached the late bipinnaria / early brachiolaria stage compared to starved starfish. Females on Acropora diet also produced a higher proportion of larvae that progressed to more advanced stages faster compared to Porites-fed starfish, which progressed faster than starved starfish. These results suggest that maternal provisioning can have important consequences for the quality and quantity of progeny. Because food quality (coral community structure) and quantity (coral abundance) varies widely among reef locations and habitats, local variation in maternal nutrition of A. planci is likely to moderate reproductive success and may explain temporal and spatial fluctuations in abundance of this species. PMID:27327627

  5. Species-Specific Responses of Corals to Bleaching Events on Anthropogenically Turbid Reefs on Okinawa Island, Japan, over a 15-year Period (1995–2009)

    PubMed Central

    Hongo, Chuki; Yamano, Hiroya

    2013-01-01

    Coral bleaching, triggered by elevated sea-surface temperatures (SSTs) has caused a decline in coral cover and changes in the abundances of corals on reefs worldwide. Coral decline can be exacerbated by the effects of local stressors like turbidity, yet some reefs with a natural history of turbidity can support healthy and resilient coral communities. However, little is known about responses of coral communities to bleaching events on anthropogenically turbid reefs as a result of recent (post World War II) terrestrial runoff. Analysis of region-scale coral cover and species abundance at 17–20 sites on the turbid reefs of Okinawa Island (total of 79 species, 30 genera, and 13 families) from 1995 to 2009 indicates that coral cover decreased drastically, from 24.4% to 7.5% (1.1%/year), subsequent to bleaching events in 1998 and 2001. This dramatic decrease in coral cover corresponded to the demise of Acropora species (e.g., A. digitifera) by 2009, when Acropora had mostly disappeared from turbid reefs on Okinawa Island. In contrast, Merulinidae species (e.g., Dipsastraea pallida/speciosa/favus) and Porites species (e.g., P. lutea/australiensis), which are characterized by tolerance to thermal stress, survived on turbid reefs of Okinawa Island throughout the period. Our results suggest that high turbidity, influenced by recent terrestrial runoff, could have caused a reduction in resilience of Acropora species to severe thermal stress events, because the corals could not have adapted to a relatively recent decline in water quality. The coral reef ecosystems of Okinawa Island will be severely impoverished if Acropora species fail to recover. PMID:23565291

  6. Recent disturbances augment community shifts in coral assemblages in Moorea, French Polynesia

    NASA Astrophysics Data System (ADS)

    Pratchett, M. S.; Trapon, M.; Berumen, M. L.; Chong-Seng, K.

    2011-03-01

    Coral reefs are often subject to disturbances that can cause enduring changes in community structure and abundance of coral reef organisms. In Moorea, French Polynesia, frequent disturbances between 1979 and 2003 caused marked shifts in taxonomic composition of coral assemblages. This study explores recent changes in live cover and taxonomic structure of coral communities on the north coast of Moorea, French Polynesia, to assess whether coral assemblages are recovering (returning to a previous Acropora-dominated state) or continuing to move towards an alternative community structure. Coral cover declined by 29.7% between July 2003 and March 2009, mostly due to loss of Acropora and Montipora spp. Coral mortality varied among habitats, with highest levels of coral loss on the outer reef slope (7-20 m depth). In contrast, there was limited change in coral cover within the lagoon, and coral cover actually increased on the reef crest. Observed changes in coral cover and composition correspond closely with the known feeding preferences and observed spatial patterns of Acanthaster planci L., though observed coral loss also coincided with at least one episode of coral bleaching, as well as persistent populations of the corallivorous starfish Culcita novaeguineae Muller & Troschel. While climate change poses an important and significant threat to the future structure and dynamics coral reef communities, outbreaks of A. planci remain a significant cause of coral loss in Moorea. More importantly, these recent disturbances have followed long-term shifts in the structure of coral assemblages, and the relative abundance of both Pocillopora and Porites continue to increase due to disproportionate losses of Acropora and Montipora. Moreover, Pocillopora and Porites dominate assemblages of juvenile corals, suggesting that there is limited potential for a return to an Acropora-dominated state, last recorded in 1979.

  7. The Role of Maternal Nutrition on Oocyte Size and Quality, with Respect to Early Larval Development in The Coral-Eating Starfish, Acanthaster planci.

    PubMed

    Caballes, Ciemon Frank; Pratchett, Morgan S; Kerr, Alexander M; Rivera-Posada, Jairo A

    2016-01-01

    Variation in local environmental conditions can have pronounced effects on the population structure and dynamics of marine organisms. Previous studies on crown-of-thorns starfish, Acanthaster planci, have primarily focused on effects of water quality and nutrient availability on larval growth and survival, while the role of maternal nutrition on reproduction and larval development has been overlooked. To examine the effects of maternal nutrition on oocyte size and early larval development in A. planci, we pre-conditioned females for 60 days on alternative diets of preferred coral prey (Acropora abrotanoides) versus non-preferred coral prey (Porites rus) and compared resulting gametes and progeny to those produced by females that were starved over the same period. Females fed ad libitum with Acropora increased in weight, produced heavier gonads and produced larger oocytes compared to Porites-fed and starved females. Fed starfish (regardless of whether it was Acropora or Porites) produced bigger larvae with larger stomachs and had a higher frequency of normal larvae that reached the late bipinnaria / early brachiolaria stage compared to starved starfish. Females on Acropora diet also produced a higher proportion of larvae that progressed to more advanced stages faster compared to Porites-fed starfish, which progressed faster than starved starfish. These results suggest that maternal provisioning can have important consequences for the quality and quantity of progeny. Because food quality (coral community structure) and quantity (coral abundance) varies widely among reef locations and habitats, local variation in maternal nutrition of A. planci is likely to moderate reproductive success and may explain temporal and spatial fluctuations in abundance of this species. PMID:27327627

  8. Pulley reef: a deep photosynthetic coral reef on the West Florida Shelf, USA

    USGS Publications Warehouse

    Culter, J.K.; Ritchie, K.B.; Earle, S.A.; Guggenheim, D.E.; Halley, R.B.; Ciembronowicz, K.T.; Hine, A.C.; Jarrett, B.D.; Locker, S.D.; Jaap, W.C.

    2006-01-01

    Pulley Reef (24°50′N, 83°40′W) lies on a submerged late Pleistocene shoreline feature that formed during a sea-level stillstand from 13.8 to 14.5 ka (Jarrett et al. 2005). The reef is currently 60–75 m deep, exhibits 10–60% coral cover, and extends over approximately 160 km2 of the sea floor. Zooxanthellate corals are primarily Agaricia lamarcki, A. fragilis, Leptoseris cucullata, and less common Madracis formosa, M. pharensis, M. decactis, Montastraea cavernosa, Porites divaricata, Scolymia cubensis and Oculina tenella. Coralline algae are comparable in abundance to stony corals. Other macroalgae include Halimeda tuna, Dictyota divaricata, Lobophora variegata, Ventricatri ventricosa, Verdigelas pelas, and Kallymenia sp. Anadyomene menziesii is abundant. The reef provides a habitat for organisms typically observed at much shallower depths, and is the deepest known photosynthetic coral reef on the North America continental shelf (Fig. 1).

  9. Predation on coral settlers by the corallivorous fireworm Hermodice carunculata

    NASA Astrophysics Data System (ADS)

    Wolf, A. T.; Nugues, M. M.

    2013-03-01

    Coral predation by the fireworm Hermodice carunculata was investigated by presenting settlers (<3-week-old) and adults of two species of Caribbean corals, Montastraea faveolata and Agaricia humilis, to three different size classes of fireworms under laboratory conditions. For both coral species, survival rates of settlers were low (<2 % after 4 days), intermediate (42-54 %) and high (>90 %) in the presence of small-, mid- and large-sized fireworms, respectively. In contrast, fireworms hardly preyed on adult corals, irrespective of their sizes. Our results suggest an ontogenic shift in the diet of H. carunculata and in the susceptibility of corals to predation by fireworms. H. carunculata, in particular small-sized individuals, could be an important cause for early post-settlement mortality in corals. The corallivore could reinforce recruitment bottlenecks and reduce coral recovery after disturbances.

  10. Local Stressors Reduce Coral Resilience to Bleaching

    PubMed Central

    Carilli, Jessica E.; Norris, Richard D.; Black, Bryan A.; Walsh, Sheila M.; McField, Melanie

    2009-01-01

    Coral bleaching, during which corals lose their symbiotic dinoflagellates, typically corresponds with periods of intense heat stress, and appears to be increasing in frequency and geographic extent as the climate warms. A fundamental question in coral reef ecology is whether chronic local stress reduces coral resistance and resilience from episodic stress such as bleaching, or alternatively promotes acclimatization, potentially increasing resistance and resilience. Here we show that following a major bleaching event, Montastraea faveolata coral growth rates at sites with higher local anthropogenic stressors remained suppressed for at least 8 years, while coral growth rates at sites with lower stress recovered in 2–3 years. Instead of promoting acclimatization, our data indicate that background stress reduces coral fitness and resilience to episodic events. We also suggest that reducing chronic stress through local coral reef management efforts may increase coral resilience to global climate change. PMID:19623250

  11. Chronic parrotfish grazing impedes coral recovery after bleaching

    NASA Astrophysics Data System (ADS)

    Rotjan, Randi D.; Dimond, James L.; Thornhill, Daniel J.; Leichter, James J.; Helmuth, Brian; Kemp, Dustin W.; Lewis, Sara M.

    2006-08-01

    Coral bleaching, in which corals become visibly pale and typically lose their endosymbiotic zooxanthellae ( Symbiodinium spp.), increasingly threatens coral reefs worldwide. While the proximal environmental triggers of bleaching are reasonably well understood, considerably less is known concerning physiological and ecological factors that might exacerbate coral bleaching or delay recovery. We report a bleaching event in Belize during September 2004 in which Montastraea spp. corals that had been previously grazed by corallivorous parrotfishes showed a persistent reduction in symbiont density compared to intact colonies. Additionally, grazed corals exhibited greater diversity in the genetic composition of their symbiont communities, changing from uniform ITS2 type C7 Symbiodinium prior to bleaching to mixed assemblages of Symbiodinium types post-bleaching. These results suggest that chronic predation may exacerbate the influence of environmental stressors and, by altering the coral-zooxanthellae symbiosis, such abiotic-biotic interactions may contribute to spatial variation in bleaching processes.

  12. Local stressors reduce coral resilience to bleaching.

    PubMed

    Carilli, Jessica E; Norris, Richard D; Black, Bryan A; Walsh, Sheila M; McField, Melanie

    2009-07-22

    Coral bleaching, during which corals lose their symbiotic dinoflagellates, typically corresponds with periods of intense heat stress, and appears to be increasing in frequency and geographic extent as the climate warms. A fundamental question in coral reef ecology is whether chronic local stress reduces coral resistance and resilience from episodic stress such as bleaching, or alternatively promotes acclimatization, potentially increasing resistance and resilience. Here we show that following a major bleaching event, Montastraea faveolata coral growth rates at sites with higher local anthropogenic stressors remained suppressed for at least 8 years, while coral growth rates at sites with lower stress recovered in 2-3 years. Instead of promoting acclimatization, our data indicate that background stress reduces coral fitness and resilience to episodic events. We also suggest that reducing chronic stress through local coral reef management efforts may increase coral resilience to global climate change.

  13. Macroalgae Has No Effect on the Severity and Dynamics of Caribbean Yellow Band Disease

    PubMed Central

    Vu, Ivana; Smelick, Gillian; Harris, Sam; Lee, Sarah C.; Weil, Ernesto; Whitehead, Robert F.; Bruno, John F.

    2009-01-01

    By removing herbivores and promoting increases in macroalgae, overfishing is thought to indirectly cause coral disease and mortality. We performed three field manipulations to test the general hypothesis that overfishing and the subsequent alteration of coral reef trophic dynamics are a cause of coral epizootics. Specifically, we asked whether the presence of macroalgae can influence within- and among-colony spread rates of Caribbean Yellow Band Disease in Montastraea faveolata. Macroalgae were placed next to infected and healthy, adult and small coral colonies to measure effects on disease spread rate, coral growth and coral survival. Surprisingly, the addition of macroalgae did not affect disease severity or coral fitness. Our results indicate that macroalgae have no effect on the severity and dynamics of Caribbean Yellow Band Disease and that fisheries management alone will not mitigate the effects of this important epizootic. PMID:19223986

  14. A microsampling method for genotyping coral symbionts

    NASA Astrophysics Data System (ADS)

    Kemp, D. W.; Fitt, W. K.; Schmidt, G. W.

    2008-06-01

    Genotypic characterization of Symbiodinium symbionts in hard corals has routinely involved coring, or the removal of branches or a piece of the coral colony. These methods can potentially underestimate the complexity of the Symbiodinium community structure and may produce lesions. This study demonstrates that microscale sampling of individual coral polyps provided sufficient DNA for identifying zooxanthellae clades by RFLP analyses, and subclades through the use of PCR amplification of the ITS-2 region of rDNA and denaturing-gradient gel electrophoresis. Using this technique it was possible to detect distinct ITS-2 types of Symbiodinium from two or three adjacent coral polyps. These methods can be used to intensely sample coral-symbiont population/communities while causing minimal damage. The effectiveness and fine scale capabilities of these methods were demonstrated by sampling and identifying phylotypes of Symbiodinium clades A, B, and C that co-reside within a single Montastraea faveolata colony.

  15. A 107-year-old coral from Florida Bay: barometer of natural and man- induced catastrophes?

    USGS Publications Warehouse

    Hudson, J.H.; Powell, G.V.N.; Robblee, M.B.; Smith, T. J.

    1989-01-01

    The 107-yr growth history of a massive coral Solenastrea bournoni from Florida Bay was reconstructed with X-ray imagery from a single 4 in. diameter (10 cm) core that penetrated the exact epicenter of the 95.3 cm high colony. Growth increments totalled 952.9 mm, averaging 8.9 mm/yr over the life of the coral. Growth rate trends in the Florida Bay coral were compared to those in a Montastraea annularis of similar age from a nearby patch reef on the Atlantic Ocean side of the Florida Keys. It was concluded that growth rate, at least in these specimens, is a questionable indicator of past hurricanes and freezes. There does appear to be, however, a possible cause-and-effect relationship between major man-induced environmental perturbations and a prolonged reduction in growth rate in each coral's growth record. -from Authors

  16. Macroalgae has no effect on the severity and dynamics of Caribbean yellow band disease.

    PubMed

    Vu, Ivana; Smelick, Gillian; Harris, Sam; Lee, Sarah C; Weil, Ernesto; Whitehead, Robert F; Bruno, John F

    2009-01-01

    By removing herbivores and promoting increases in macroalgae, overfishing is thought to indirectly cause coral disease and mortality. We performed three field manipulations to test the general hypothesis that overfishing and the subsequent alteration of coral reef trophic dynamics are a cause of coral epizootics. Specifically, we asked whether the presence of macroalgae can influence within- and among-colony spread rates of Caribbean Yellow Band Disease in Montastraea faveolata. Macroalgae were placed next to infected and healthy, adult and small coral colonies to measure effects on disease spread rate, coral growth and coral survival. Surprisingly, the addition of macroalgae did not affect disease severity or coral fitness. Our results indicate that macroalgae have no effect on the severity and dynamics of Caribbean Yellow Band Disease and that fisheries management alone will not mitigate the effects of this important epizootic.

  17. Palaeoecological evidence of a historical collapse of corals at Pelorus Island, inshore Great Barrier Reef, following European settlement

    PubMed Central

    Roff, George; Clark, Tara R.; Reymond, Claire E.; Zhao, Jian-xin; Feng, Yuexing; McCook, Laurence J.; Done, Terence J.; Pandolfi, John M.

    2013-01-01

    The inshore reefs of the Great Barrier Reef (GBR) have undergone significant declines in water quality following European settlement (approx. 1870 AD). However, direct evidence of impacts on coral assemblages is limited by a lack of historical baselines prior to the onset of modern monitoring programmes in the early 1980s. Through palaeoecological reconstructions, we report a previously undocumented historical collapse of Acropora assemblages at Pelorus Island (central GBR). High-precision U-series dating of dead Acropora fragments indicates that this collapse occurred between 1920 and 1955, with few dates obtained after 1980. Prior to this event, our results indicate remarkable long-term stability in coral community structure over centennial scales. We suggest that chronic increases in sediment flux and nutrient loading following European settlement acted as the ultimate cause for the lack of recovery of Acropora assemblages following a series of acute disturbance events (SST anomalies, cyclones and flood events). Evidence for major degradation in reef condition owing to human impacts prior to modern ecological surveys indicates that current monitoring of inshore reefs on the GBR may be predicated on a significantly shifted baseline. PMID:23135672

  18. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago.

    PubMed

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-12-10

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history.

  19. Phylogenetic evidence for recent diversification of obligate coral-dwelling gobies compared with their host corals☆

    PubMed Central

    Duchene, David; Klanten, Selma O.; Munday, Philip L.; Herler, Jürgen; van Herwerden, Lynne

    2013-01-01

    The rich diversity of coral reef organisms is supported, at least in part, by the diversity of coral reef habitat. Some of the most habitat specialised fishes on coral reefs are obligate coral-dwelling gobies of the genus Gobiodon that inhabit a range of coral species, mostly of the genus Acropora. However, the role of this specialised pattern of habitat use in the evolution of coral-dwelling gobies is not well understood. Diversification of coral-dwelling gobies may be driven by the diversification of their host corals (cospeciation), or alternatively, diversification of these fishes may have occurred independently of the diversification of host corals. The cospeciation hypothesis assumes similar timing in evolution of the gobies and their host corals. We used four genes for each group and the available fossil records to reconstruct and date phylogenies for 20 species of Gobiodon from the Indo-Pacific and the Red Sea, and for 28 species of the coral genus Acropora. Our results indicate that Gobiodon diversified mostly in the last ∼5 My, whereas Acropora corals have consistently diversified since the Eocene, making the hypothesis of cospeciation untenable. The fully resolved molecular phylogeny of the genus Gobiodon is in part at odds with previous analyses incorporating morphological data and indicates that some morphological traits form paraphyletic clades within Gobiodon. Our phylogeny supports a hypothesis in which Gobiodon diversified in the Indo-Pacific Ocean and then radiated recently, with multiple new variants found in the Red Sea. PMID:23680856

  20. Changes in coral assemblages during an outbreak of Acanthaster planci at Lizard Island, northern Great Barrier Reef (1995-1999)

    NASA Astrophysics Data System (ADS)

    Pratchett, M. S.

    2010-09-01

    Population outbreaks of crown-of-thorns starfish ( Acanthaster planci L.) represent one of the most significant biological disturbances on tropical coral reefs and have the potential to devastate coral communities, thereby altering the biological and physical structure of reef habitats. This study reports on changes in area cover, species diversity and taxonomic composition of corals during an outbreak of A. planci at Lizard Island, in the northern Great Barrier Reef, Australia. Mean coral cover declined by 28.8% across ten locations studied. However, densities of A. planci, and their effects on local coral assemblages, were very patchy. Declines in coral cover were mostly due to the selective removal of certain coral taxa (mainly Acropora and Pocilloporidae corals); such that the greatest coral loss occurred at locations with highest initial cover of preferred coral prey. Most notably, coral assemblages in back-reef locations were transformed from topographically complex staghorn Acropora-dominated habitats, to relatively depauperate assemblages dominated by alcyonacean soft corals. Although coral loss was greatest among formerly dominant taxa (especially Acropora), effects were sufficiently widespread across different coral taxa, such that overall coral diversity tended to decline. Clearly, moderate outbreaks of A. planci have the potential to greatly alter community structure of coral communities even if they do not devastate live corals. Recovery in this instance is expected to be very rapid given that all coral taxa persisted, and effects were greatest among fast growing corals.

  1. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago

    PubMed Central

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-01-01

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history. PMID:26656261

  2. The effect of structurally complex corals and herbivory on the dynamics of Halimeda

    NASA Astrophysics Data System (ADS)

    Castro-Sanguino, Carolina; Lovelock, Catherine; Mumby, Peter J.

    2016-06-01

    The calcareous green alga Halimeda is a key contributor to carbonate sediment production on coral reefs. As herbivores have a direct negative effect on the abundance of Halimeda, protection from herbivory is critical for Halimeda growth. Branching corals such as Acropora are likely to provide refugia for Halimeda from grazers, yet studies are scarce. Here, we investigated the vulnerability of two Halimeda species to herbivory using fish exclusion cages and assessed the contribution of coral structural complexity to seasonal changes in Halimeda biomass and morphometrics. While up to 50 % Halimeda abundance was depleted outside cages due to herbivory and the exclusion of large herbivores resulted in an increase in net growth up to threefold, Halimeda recruitment was positively affected by herbivory, more than two times greater outside cages. However, these responses differed between species and seasons; only one species was affected in winter but not summer. Coral structural complexity facilitated an increase of total algal biomass particularly in summer. At the individual level, thalli growing inside the Acropora canopy were always significantly larger (thallus biomass, volume and height) than those growing in exposed areas. We estimated that the carbonate production of Halimeda was nearly three times greater inside refuges provided by Acropora. Because Halimeda species differ in growth rates and susceptibility to grazing, we predict that the ongoing degradation of the habitat complexity provided by branching corals will alter Halimeda community structure and its contribution to local sediment budgets.

  3. Reef coralgal assemblages as recorders of paleobathymetry and sea level changes in the Indo-Pacific province

    NASA Astrophysics Data System (ADS)

    Cabioch, G.; Montaggioni, L. F.; Faure, G.; Ribaud-Laurenti, A.

    1999-12-01

    The coralgal framework within the outer reef margin of many Indo-Pacific reefs exhibits three main shallow-water communities, the environmental significance of which can be inferred by comparison with their modern counterparts. A community dominated by tabular Acropora gr. hyacinthus/ cytherea with branching Pocillopora damicornis, P. eydouxi, Montipora digitata, occasional domal faviids and mm-thick crusts of the coralline algae Lithophyllum and Mesophyllum (mainly), typical of the 6 - 15 m paleodepth range; a community including robust-branching Acropora gr. danai/ robusta, A. humilis, A. digitifera and subordinate Favia stelligera, Echinopora gemmacea, associated to vermetid gastropods and thick coralline crusts of Hydrolithon cf. onkodes and Neogoniolithon cf. fosliei flourishing in depths less than 6 m; in medium-to-high water-energy settings, a community composed of domal Porites cf. lutea and P. cf. lobata with occasional Acropora gr. danai/ robusta and cm-thick crusts of coralline algae in sheltered habitats in depths less than 10 m. These biological assemblages allow us to determine relationships between reef growth and paleobathymetry and, consequently, to reconstruct regional relative sea-level curves. High water-energy reefal assemblages provide stronger evidence for reconstructing sea-level curves than low-energy buildups, because they have generally been controlled by a keep-up growth mode. Subsiding reef sites seem to be more reliable indicators of sea-level variations because they usually present expanded reef sequences.

  4. Depth-dependent mortality of reef corals following a severe bleaching event: implications for thermal refuges and population recovery.

    PubMed

    Bridge, Tom C L; Hoey, Andrew S; Campbell, Stuart J; Muttaqin, Efin; Rudi, Edi; Fadli, Nur; Baird, Andrew H

    2013-01-01

    Coral bleaching caused by rising sea temperature is a primary cause of coral reef degradation. However, bleaching patterns often show significant spatial variability, therefore identifying locations where local conditions may provide thermal refuges is a high conservation priority. Coral bleaching mortality often diminishes with increasing depth, but clear depth zonation of coral communities and putative limited overlap in species composition between deep and shallow reef habitats has led to the conclusion that deeper reef habitats will provide limited refuge from bleaching for most species. Here, we show that coral mortality following a severe bleaching event diminished sharply with depth. Bleaching-induced mortality of Acropora was approximately 90% at 0-2m, 60% at 3-4 m, yet at 6-8m there was negligible mortality. Importantly, at least two-thirds of the shallow-water (2-3 m) Acropora assemblage had a depth range that straddled the transition from high to low mortality. Cold-water upwelling may have contributed to the lower mortality observed in all but the shallowest depths. Our results demonstrate that, in this instance, depth provided a refuge for individuals from a high proportion of species in this Acropora-dominated assemblage. The persistence of deeper populations may provide a critical source of propagules to assist recovery of adjacent shallow-water reefs.

  5. Palaeoecological evidence of a historical collapse of corals at Pelorus Island, inshore Great Barrier Reef, following European settlement.

    PubMed

    Roff, George; Clark, Tara R; Reymond, Claire E; Zhao, Jian-xin; Feng, Yuexing; McCook, Laurence J; Done, Terence J; Pandolfi, John M

    2013-01-01

    The inshore reefs of the Great Barrier Reef (GBR) have undergone significant declines in water quality following European settlement (approx. 1870 AD). However, direct evidence of impacts on coral assemblages is limited by a lack of historical baselines prior to the onset of modern monitoring programmes in the early 1980s. Through palaeoecological reconstructions, we report a previously undocumented historical collapse of Acropora assemblages at Pelorus Island (central GBR). High-precision U-series dating of dead Acropora fragments indicates that this collapse occurred between 1920 and 1955, with few dates obtained after 1980. Prior to this event, our results indicate remarkable long-term stability in coral community structure over centennial scales. We suggest that chronic increases in sediment flux and nutrient loading following European settlement acted as the ultimate cause for the lack of recovery of Acropora assemblages following a series of acute disturbance events (SST anomalies, cyclones and flood events). Evidence for major degradation in reef condition owing to human impacts prior to modern ecological surveys indicates that current monitoring of inshore reefs on the GBR may be predicated on a significantly shifted baseline.

  6. Genome-wide SNP analysis explains coral diversity and recovery in the Ryukyu Archipelago.

    PubMed

    Shinzato, Chuya; Mungpakdee, Sutada; Arakaki, Nana; Satoh, Noriyuki

    2015-01-01

    Following a global coral bleaching event in 1998, Acropora corals surrounding most of Okinawa island (OI) were devastated, although they are now gradually recovering. In contrast, the Kerama Islands (KIs) only 30 km west of OI, have continuously hosted a great variety of healthy corals. Taking advantage of the decoded Acropora digitifera genome and using genome-wide SNP analyses, we clarified Acropora population structure in the southern Ryukyu Archipelago (sRA). Despite small genetic distances, we identified distinct clusters corresponding to specific island groups, suggesting infrequent long-distance dispersal within the sRA. Although the KIs were believed to supply coral larvae to OI, admixture analyses showed that such dispersal is much more limited than previously realized, indicating independent recovery of OI coral populations and the necessity of local conservation efforts for each region. We detected strong historical migration from the Yaeyama Islands (YIs) to OI, and suggest that the YIs are the original source of OI corals. In addition, migration edges to the KIs suggest that they are a historical sink population in the sRA, resulting in high diversity. This population genomics study provides the highest resolution data to date regarding coral population structure and history. PMID:26656261

  7. Habitat preferences of a corallivorous reef fish: predation risk versus food quality

    NASA Astrophysics Data System (ADS)

    Brooker, R. M.; Munday, P. L.; Mcleod, I. M.; Jones, G. P.

    2013-09-01

    Many animals preferentially select a habitat from a range of those potentially available. However, the consequences of these preferences for distribution and abundance, and the underlying basis of habitat preferences are often unknown. The present study, conducted at Great Keppel Island, Australia, examined how distribution and abundance of an obligate corallivorous filefish, Oxymonacanthus longirostris, relates to coral architecture and diversity. The main drivers of the distribution and abundance of O. longirostris among reefs were coral species richness and availability of branching coral. Feeding territories had a higher percentage of Acropora coral than surrounding habitat. In addition, feeding territories had a higher percentage of the structurally important branching coral, Acropora nobilis, and a primary prey species, Acropora millepora. A series of pair-wise choice experiments in which both structural complexity and coral tissue quality were independently manipulated showed that habitat choice was primarily based on structural complexity and shelter characteristics. In addition, the choice for the preferred coral ( A. nobilis) was stronger in the presence of a piscivorous fish. These results indicate that species-diverse coral habitats, which provide sufficient structural complexity along with nutritionally important prey, are essential for population persistence of this small, corallivorous reef fish.

  8. Linear extension rates of massive corals from the Dry Tortugas National Park (DRTO), Florida

    USGS Publications Warehouse

    Muslic, Adis; Flannery, Jennifer A.; Reich, Christopher D.; Umberger, Daniel K.; Smoak, Joseph M.; Poore, Richard Z.

    2013-01-01

    Colonies of three coral species, Montastraea faveolata, Diploria strigosa, and Siderastrea siderea, located in the Dry Tortugas National Park (DRTO), Florida, were sampled and analyzed to evaluate annual linear extension rates. Montastraea faveolata had the highest average linear extension and variability in (DRTO: C2 = 0.67 centimeters/year (cm yr-1) ± 0.04, B3 = 0.85 cm yr-1 ± 0.07), followed by D. strigosa (DRTO: C1 = 0.73 cm yr-1 ± 0.04; MK = 0.59 cm yr-1 ± 0.06) and S. siderea (DRTO: A1 = 0.41 cm yr-1 ± 0.03). Intercolony comparison of M. faveolata from DRTO yielded a significant correlation (r = 0.34, df = 67, P = 0.005) and similar long-term patterns. DRTO S. siderea core A1 showed an overall increasing trend (r = 0.61, df = 119, P < 0.0001) in extension rates that correlated significantly with International Comprehensive Ocean/Atmosphere Data Set annual sea-surface temperature (r = 0.42, df = 115, P < 0.0001) and an air temperature record from Key West (r = 0.37, df = 111, P < 0.0001). In conclusion, annual linear extension rates are species specific and potentially influence by long-term variability in sea-surface temperature.

  9. The Importance of Coral Larval Recruitment for the Recovery of Reefs Impacted by Cyclone Yasi in the Central Great Barrier Reef

    PubMed Central

    Lukoschek, Vimoksalehi; Cross, Peter; Torda, Gergely; Zimmerman, Rachel; Willis, Bette L.

    2013-01-01

    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. PMID:23755223

  10. Coral transplantation as an aid to reef rehabilitation: evaluation of a case study in the Maldive Islands

    NASA Astrophysics Data System (ADS)

    Clark, S.; Edwards, A. J.

    1995-11-01

    As part of a study of reef rehabilitation, whole coral colonies (primarily Acropora, Pocillopora, Porites, Favia and Favites) were transplanted and cemented in place onto three approximately 20 m2 areas of Armorflex concrete mats on a 0.8-1.5 m deep reef-flat in the Maldives which had been severely degraded by coral mining. Growth, in situ mortality, and losses from mats due to wave action of a total of 530 transplants were monitored over 28 months. Natural recruitment of corals to both the transplanted Armorflex areas and concrete mats without transplants was also studied. Overall survivorship of corals 28 months after transplantation was 51%. Most losses of transplants due to wave action occurred during the first 7 months when 25% were lost, with only a further 5% of colonies being lost subsequently. Within 16 months most colonies had accreted naturally to the concrete mats. Thirty-two percent of transplants which remained attached died with Acropora hyacinthus and Pocillopora verrucosa having the highest mortality rates (approx. 50% mortality over two years) and Porites lobata and P. lutea the lowest (2.8 and 8.1% mortality respectively over two years). Growth rates were very variable with a quarter to a third of transplants showing negative growth during each inter-survey period. Acropora hyacinthus, A. cytherea and A. divaricata transplants had the highest growth rates (colony mean linear radial extension 4.15-5.81 cm y-1), followed by Pocillopora verrucosa (mean 2.51 cm y-1). Faviids and poritids had lowest growth rates. Favia and Favites showed the poorest response to transplantation whilst Acropora divaricata, which combined a high growth rate with relatively low mortality, appeared particularly amenable to transplantation. Natural recruitment did not differ significantly between concrete mats with and without transplanted corals. `Visible' recruits were first recorded 10 months after emplacement of the mats and were predominantly Acropora and Pocillopora

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

    PubMed

    Lukoschek, Vimoksalehi; Cross, Peter; Torda, Gergely; Zimmerman, Rachel; Willis, Bette L

    2013-01-01

    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.

  12. Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2010-31 January 2011.

    PubMed

    Agata, Kiyokazu; Alasaad, Samer; Almeida-Val, Vera Maria Fonseca; Alvarez-Dios, J A; Barbisan, F; Beadell, Jon S; Beltrán, J F; Benítez, M; Bino, G; Bleay, Colin; Bloor, P; Bohlmann, Jörg; Booth, Warren; Boscari, E; Caccone, Adalgisa; Campos, Tatiana; Carvalho, B M; Climaco, Gisele Torres; Clobert, Jean; Congiu, L; Cowger, Christina; Dias, G; Doadrio, I; Farias, Izeni Pires; Ferrand, N; Freitas, Patrícia D; Fusco, G; Galetti, Pedro M; Gallardo-Escárate, Cristian; Gaunt, Michael W; Ocampo, Zaneli Gomez; Gonçalves, H; Gonzalez, E G; Haye, Pilar; Honnay, O; Hyseni, Chaz; Jacquemyn, H; Jowers, Michael J; Kakezawa, Akihiro; Kawaguchi, Eri; Keeling, Christopher I; Kwan, Ye-Seul; La Spina, Michelangelo; Lee, Wan-Ok; Leśniewska, M; Li, Yang; Liu, Haixia; Liu, Xiaolin; Lopes, S; Martínez, P; Meeus, S; Murray, Brent W; Nunes, Aline G; Okedi, Loyce M; Ouma, Johnson O; Pardo, B G; Parks, Ryan; Paula-Silva, Maria Nazaré; Pedraza-Lara, C; Perera, Omaththage P; Pino-Querido, A; Richard, Murielle; Rossini, Bruno C; Samarasekera, N Gayathri; Sánchez, Antonio; Sanchez, Juan A; Santos, Carlos Henrique Dos Anjos; Shinohara, Wataru; Soriguer, Ramón C; Sousa, Adna Cristina Barbosa; Sousa, Carolina Fernandes Da Silva; Stevens, Virginie M; Tejedo, M; Valenzuela-Bustamante, Myriam; Van de Vliet, M S; Vandepitte, K; Vera, M; Wandeler, Peter; Wang, Weimin; Won, Yong-Jin; Yamashiro, A; Yamashiro, T; Zhu, Changcheng

    2011-05-01

    This article documents the addition of 238 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alytes dickhilleni, Arapaima gigas, Austropotamobius italicus, Blumeria graminis f. sp. tritici, Cobitis lutheri, Dendroctonus ponderosae, Glossina morsitans morsitans, Haplophilus subterraneus, Kirengeshoma palmata, Lysimachia japonica, Macrolophus pygmaeus, Microtus cabrerae, Mytilus galloprovincialis, Pallisentis (Neosentis) celatus, Pulmonaria officinalis, Salminus franciscanus, Thais chocolata and Zootoca vivipara. These loci were cross-tested on the following species: Acanthina monodon, Alytes cisternasii, Alytes maurus, Alytes muletensis, Alytes obstetricans almogavarii, Alytes obstetricans boscai, Alytes obstetricans obstetricans, Alytes obstetricans pertinax, Cambarellus montezumae, Cambarellus zempoalensis, Chorus giganteus, Cobitis tetralineata, Glossina fuscipes fuscipes, Glossina pallidipes, Lysimachia japonica var. japonica, Lysimachia japonica var. minutissima, Orconectes virilis, Pacifastacus leniusculus, Procambarus clarkii, Salminus brasiliensis and Salminus hilarii. PMID:21457476

  13. Ctenostomatous Bryozoa from São Paulo, Brazil, with descriptions of twelve new species.

    PubMed

    Vieira, Leandro M; Migotto, Alvaro E; Winston, Judith E

    2014-12-02

    This paper describes 21 ctenostomatous bryozoans from the state of São Paulo, Brazil, based on specimens observed in vivo. A new family, Jebramellidae n. fam., is erected for a newly described genus and species, Jebramella angusta n. gen. et sp. Eleven other species are described as new: Alcyonidium exiguum n. sp., Alcyonidium pulvinatum n. sp., Alcyonidium torquatum n. sp., Alcyonidium vitreum n. sp., Bowerbankia ernsti n. sp., Bowerbankia evelinae n. sp., Bowerbankia mobilis n. sp., Nolella elizae n. sp., Panolicella brasiliensis n. sp., Sundanella rosea n. sp., Victorella araceae n. sp. Taxonomic and ecological notes are also included for nine previously described species: Aeverrillia setigera (Hincks, 1887), Alcyonidium hauffi Marcus, 1939, Alcyonidium polypylum Marcus, 1941, Anguinella palmata van Beneden, 1845, Arachnoidella evelinae (Marcus, 1937), Bantariella firmata (Marcus, 1938) n. comb., Nolella sawayai Marcus, 1938, Nolella stipata Gosse, 1855 and Zoobotryon verticillatum (delle Chiaje, 1822).

  14. Nutraceutical potential of selected wild edible fruits of the Indian Himalayan region.

    PubMed

    Bhatt, Indra D; Rawat, Sandeep; Badhani, Amit; Rawal, Ranbeer S

    2017-01-15

    Wild edible fruits contribute significantly to the nutritional security of mankind across the globe. However, detailed analyses of health promoting bioactive compounds and antioxidants are lacking, especially in Himalayan wild edible fruits. Bioactive compounds and antioxidant potential of 10 wild edible fruits reveal that Terminalia chebula, Phyllanthus emblica and Myrica esculenta are the richest source of total phenolics; Pyaracantha crenulata, Terminalia chebula and Berberis asiatica for flavonoids; Phyllanthus emblica, Morus alba and Ficus palmata for ascorbic acid, anthocyanins, and Morus alba for β-carotene. Phenolic compounds, i.e. Gallic acid, catechin, chlorogenic acid, caffeic acid and p-coumaric acid varied among species and found the maximum in Terminalia chebula and Phyllanthus emblica. Antioxidant activity showed the significant relation with total phenolics, flavonoids and phenolic compounds. Results indicated that these species should be promoted as a natural source of antioxidant/nutraceuticals so that these antioxidants can be used for supplementing dietary foods of mountain people. PMID:27542453

  15. Phenolic content and antioxidant capacity in algal food products.

    PubMed

    Machu, Ludmila; Misurcova, Ladislava; Ambrozova, Jarmila Vavra; Orsavova, Jana; Mlcek, Jiri; Sochor, Jiri; Jurikova, Tunde

    2015-01-01

    The study objective was to investigate total phenolic content using Folin-Ciocalteu's method, to assess nine phenols by HPLC, to determine antioxidant capacity of the water soluble compounds (ACW) by a photochemiluminescence method, and to calculate the correlation coefficients in commercial algal food products from brown (Laminaria japonica, Eisenia bicyclis, Hizikia fusiformis, Undaria pinnatifida) and red (Porphyra tenera, Palmaria palmata) seaweed, green freshwater algae (Chlorella pyrenoidosa), and cyanobacteria (Spirulina platensis). HPLC analysis showed that the most abundant phenolic compound was epicatechin. From spectrophotometry and ACW determination it was evident that brown seaweed Eisenia bicyclis was the sample with the highest phenolic and ACW values (193 mg·g-1 GAE; 7.53 µmol AA·g-1, respectively). A linear relationship existed between ACW and phenolic contents (r = 0.99). Some algal products seem to be promising functional foods rich in polyphenols. PMID:25587787

  16. Non-starch polysaccharides extracted from seaweed can modulate intestinal absorption of glucose and insulin response in the pig.

    PubMed

    Vaugelade, P; Hoebler, C; Bernard, F; Guillon, F; Lahaye, M; Duee, P H; Darcy-Vrillon, B

    2000-01-01

    We have investigated the possible effects of algal polysaccharides on postprandial blood glucose and insulin responses in an animal model, the pig. Three seaweed fibres of different viscosities, extracted from Palmaria palmata (PP), Eucheuma cottonii (EC), or Laminaria digitata (LD), were compared to purified cellulose (CEL). Blood glucose and plasma insulin levels were monitored and intestinal absorption quantified for 8 h following a high carbohydrate test-meal supplemented with 5% fibre. Digestive contents were also sampled, 5 h postprandial. As compared to CEL, PP had no effect on glucose and insulin responses. The latter decreased with EC, but glucose absorption balance was not modified. LD addition resulted in a dramatically reduced glucose absorption balance, accompanied by a higher amount of starch left in the small intestine. Among polysaccharides tested, only the highly viscous alginates could affect intestinal absorption of glucose and insulin response. PMID:10737549

  17. Ctenostomatous Bryozoa from São Paulo, Brazil, with descriptions of twelve new species.

    PubMed

    Vieira, Leandro M; Migotto, Alvaro E; Winston, Judith E

    2014-01-01

    This paper describes 21 ctenostomatous bryozoans from the state of São Paulo, Brazil, based on specimens observed in vivo. A new family, Jebramellidae n. fam., is erected for a newly described genus and species, Jebramella angusta n. gen. et sp. Eleven other species are described as new: Alcyonidium exiguum n. sp., Alcyonidium pulvinatum n. sp., Alcyonidium torquatum n. sp., Alcyonidium vitreum n. sp., Bowerbankia ernsti n. sp., Bowerbankia evelinae n. sp., Bowerbankia mobilis n. sp., Nolella elizae n. sp., Panolicella brasiliensis n. sp., Sundanella rosea n. sp., Victorella araceae n. sp. Taxonomic and ecological notes are also included for nine previously described species: Aeverrillia setigera (Hincks, 1887), Alcyonidium hauffi Marcus, 1939, Alcyonidium polypylum Marcus, 1941, Anguinella palmata van Beneden, 1845, Arachnoidella evelinae (Marcus, 1937), Bantariella firmata (Marcus, 1938) n. comb., Nolella sawayai Marcus, 1938, Nolella stipata Gosse, 1855 and Zoobotryon verticillatum (delle Chiaje, 1822). PMID:25544281

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

    PubMed Central

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

    2011-01-01

    Outbreaks of coral disease have increased worldwide over the last few decades. Despite this, remarkably little is known about the ecology of disease in the Indo-Pacific Region. Here we report the spatiotemporal dynamics of a coral disease termed ‘Acroporid white syndrome’ observed to affect tabular corals of the genus Acropora on the southern Great Barrier Reef. The syndrome is characterised by rapid tissue loss initiating in the basal margins of colonies, and manifests as a distinct lesion 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. PMID:22163267

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

    PubMed

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

    2016-07-01

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

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

    PubMed

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

    2016-07-01

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

  1. First record of multi-species synchronous coral spawning from Malaysia.

    PubMed

    Chelliah, Alvin; Amar, Halimi Bin; Hyde, Julian; Yewdall, Katie; Steinberg, Peter D; Guest, James R

    2015-01-01

    Knowledge about the timing and synchrony of coral spawning has important implications for both the ecology and management of coral reef ecosystems. Data on the timing of spawning and extent of synchrony, however, are still lacking for many coral reefs, particularly from equatorial regions and from locations within the coral triangle. Here we present the first documentation of a multi-species coral spawning event from reefs around Pulau Tioman, Peninsular Malaysia, a popular diving and tourist destination located on the edge of the coral triangle. At least 8 coral species from 3 genera (Acropora, Montipora and Porites) participated in multi-species spawning over five nights in April 2014, between two nights before and two nights after the full moon. In addition, two Acropora species were witnessed spawning one night prior to the full moon in October 2014. While two of the Acropora species that reproduced in April (A. millepora and A. nasuta) exhibited highly synchronous spawning (100% of sampled colonies), two other common species (A. hyacinthus and A. digitifera) did not contain visible eggs in the majority of colonies sampled (i.e., <15% of colonies) in either April or October, suggesting that these species spawn at other times of the year. To the best of our knowledge, this is the first detailed documented observation of multi-species coral spawning from reefs in Malaysia. These data provide further support for the contention that this phenomenon is a feature of all speciose coral assemblages, including equatorial reefs. More research is needed, however, to determine the seasonal cycles and extent of spawning synchrony on these reefs and elsewhere in Malaysia. PMID:25737817

  2. Influence of corallivory, competition, and habitat structure on coral community shifts.

    PubMed

    Lenihan, Hunter S; Holbrook, Sally J; Schmitt, Russell J; Brooks, Andrew J

    2011-10-01

    The species composition of coral communities has shifted in many areas worldwide through the relative loss of important ecosystem engineers such as highly branched corals, which are integral in maintaining reef biodiversity. We assessed the degree to which the performance of recently recruited branching corals was influenced by corallivory, competition, sedimentation, and the interactions between these factors. We also explored whether the species-specific influence of these biotic and abiotic constraints helps to explain recent shifts in the coral community in lagoons of Moorea, French Polynesia. Population surveys revealed evidence of a community shift away from a historically acroporid-dominated community to a pocilloporid- and poritid-dominated community, but also showed that the distribution and abundance of coral taxa varied predictably with location in the lagoon. At the microhabitat scale, branching corals grew mainly on dead or partially dead massive Porites ("bommies"), promontories with enhanced current velocities and reduced sedimentation. A demographic study revealed that growth and survival of juvenile Pocillopora verrucosa and Acropora retusa, the two most common branching species of each taxon, were affected by predation and competition with vermetid gastropods. By 24 months of age, 20-60% of juvenile corals suffered partial predation by corallivorous fishes, and injured corals experienced reduced growth and survival. A field experiment confirmed that partial predation by corallivorous fishes is an important, but habitat-modulated, constraint for branching corals. Competition with vermetid gastropods reduced growth of both branching species but unexpectedly also provided an associational defense against corallivory. Overall, the impact of abiotic constraints was habitat-specific and similar for Acropora and Pocillopora, but biotic interactions, especially corallivory, had a greater negative effect on Acropora than Pocillopora, which may explain the

  3. Influence of sperm dilution and gamete contact time on the fertilization rate of scleractinian corals

    NASA Astrophysics Data System (ADS)

    Nozawa, Yoko; Isomura, Naoko; Fukami, Hironobu

    2015-12-01

    This study presents new information on the influence of sperm dilution on the fertilization rates of eight broadcast-spawning scleractinian coral species [three Acropora species and five merulinid species (three genera)]. The presented information nearly doubled the existing information, now totaling 17 species comprising eight acroporid species and nine merulinid species. No obvious differences in the fertilization rates were observed at the family and genus levels; furthermore, the fertilization curve estimated uniquely for Favites pentagona exhibited a strong sigmoid shape, indicating the existence of species-specific variation. In addition, a general fertilization response against sperm dilution was observed for the first time in broadcast-spawning scleractinian corals. The fertilization rate peaked (>75 %) at a sperm concentration of approximately 106 sperm mL-1 (optimal concentration) and rapidly declined to <50 % at a concentration of 104 sperm mL-1. The influence of gamete contact time (10, 30, and 60 min) on fertilization rates was also examined in two Acropora and four merulinid species, at the optimal sperm concentration. No influence of gamete contact time on fertilization rates was observed in two of the examined species ( Acropora papillare and Platygyra ryukyuensis), whereas reduced fertilization rates occurred mostly in the 10-min treatment for the other species. These results suggested that broadcast-spawning scleractinian corals can rapidly fertilize, indicating that these corals have a fair chance of achieving high fertilization success in the field under optimal conditions. The sperm concentration values (e.g., 104 sperm mL-1, indicating <50 % fertilization rates) may be useful in estimating the success of in situ fertilization of broadcast-spawning scleractinian corals, particularly in degraded, low-density populations where the degree of fertilization success is of management concern. Information on the fertilization ecology of scleractinian

  4. The effect of temperature stress on coral- Symbiodinium associations containing distinct symbiont types

    NASA Astrophysics Data System (ADS)

    Fisher, P. L.; Malme, M. K.; Dove, S.

    2012-06-01

    Several studies have demonstrated that the temperature tolerance of scleractinian reef-building corals is controlled, in part, by hosting physiologically distinct symbiotic algae. We investigated the thermal tolerance of coral-algal associations within seven common species of reef-building corals hosting distinct Symbiodinium sub-clades collected from Heron Island during experimentally induced bleaching conditions. During experimental heating, photosynthetic fitness was assessed by the dark-adapted yield of PSII ( F v/ F m), and excitation pressure across PSII ( Q m) of each coral-algal association using pulse amplitude modulation fluorometry. The onset of bleaching was determined by the measurement of Symbiodinium cell density. Using the ribosomal internal transcribed spacer 2 (ITS-2) region, we showed that Symbiodinium type-coral host associations were temporally and spatially conserved in a high proportion of the colonies sampled within each species. Generally, the species Acropora millepora, Platygyra daedalea, Acropora aspera and Acropora formosa contained Symbiodinium ITS-2 type C3, whereas the species Montipora digitata, Porites cylindrica and Porites lutea contained Symbiodinium type C15. Bleaching susceptibility showed some association with Symbiodinium type, but further research is required to confirm this. Corals hosting C3 Symbiodinium displayed higher reductions in F v/ F m during heating compared to their C15 counterparts, irrespective of host species. However, a corresponding reduction in Symbiodinium density was not observed. Nonetheless, A. aspera and A. formosa showed significant reductions in Symbiodinium density relative to controls. This correlated with large increases in Q m and decreases in F v/ F m in heated explants. Our results suggest a range of bleaching susceptibilities for the coral species investigated, with A. aspera and A. formosa showing the greatest susceptibility to bleaching and M. digitata showing the lowest bleaching

  5. Multi-species spawning synchrony within scleractinian coral assemblages in the Red Sea

    NASA Astrophysics Data System (ADS)

    Bouwmeester, J.; Baird, A. H.; Chen, C. J.; Guest, J. R.; Vicentuan, K. C.; Berumen, M. L.

    2015-03-01

    Early work on coral reproduction in the far northern Red Sea suggested that the spawning times of ecologically abundant species did not overlap, unlike on the Great Barrier Reef where many species spawn with high synchrony. In contrast, recent work in the northern and central Red Sea indicates a high degree of synchrony in the reproductive condition of Acropora species: over 90 % of species sampled in April/May contain mature gametes. However, it has yet to be determined when most Acropora release their gametes. In addition, there is a lack of data for other ecologically important scleractinian species such as merulinids and poritids. Here, we document the date and time of spawning for 51 species in the central Red Sea over three consecutive years, and the month of spawning for an additional 17 species inferred from the presence of mature gametes. Spawning occurs on nights around the full moon, the spawning season lasts at least 4 months from April until July, and observations are consistent with the few other records from the Red Sea. The number of Acropora species spawning was highest in April with 13 species spawning two nights before the full moon in 2011, 13 species spawning on the night of the full moon in 2012, and eight species spawning four nights after the full moon in 2013. The total number of species spawning was high in April, May, and June and involved 15-19 species per month in 2012. Only four species spawned in July 2012. Few regions worldwide have been similarly sampled and include the Philippines, Okinawa in Japan, and Palau, where spawning patterns are very similar to those in the central Red Sea and where corals spawn on nights around the full moon over a period of 3-4 months. In particular, in all four locations, Acropora are among the first species to spawn. Our results add to a growing body of evidence indicating that multi-species spawning synchrony is a feature of all speciose coral assemblages.

  6. Does light explain damselfish Chromis viridis abundances observed over coral colonies?

    PubMed

    Ponton, D; Loiseau, N; Chabanet, P

    2012-06-01

    A single autonomous video camera was used to record the abundances of Chromis viridis over a branching Acropora sp. colony eight times per day over a period of 50 days. The poor explanatory power of global radiation suggests the need for recording the light really available to the fish, especially in the UV range. The increasing number of C. viridis observed with increasing wind along shore and water level may correspond to individuals swimming further from their shelter in order to get closer to the food carried by the water currents.

  7. Abundance, composition and growth rate of coral recruits on dead corals following the 2010 bleaching event at Mu Ko Surin, the Andaman Sea

    NASA Astrophysics Data System (ADS)

    Yucharoen, Mathinee; Yeemin, Thamasak; Casareto, Beatriz E.; Suzuki, Yoshimi; Samsuvan, Watchara; Sangmanee, Kanwara; Klinthong, Wanlaya; Pengsakun, Sittiporn; Sutthacheep, Makamas

    2015-06-01

    Elevated seawater temperatures in the summer months of 2010 were associated with widespread coral mortality in Thailand. A large number of corals at Mu Ko Surin died following the bleaching event. Understanding of the recruitment of corals would improve our ability to predict the potential for coral recovery from the impacts of bleaching events, as well as the interpretation of spatio-temporal variability in coral community structure. This study aims to examine the composition, abundance and growth rate of juvenile corals and the potential of reef recovery at Mu Ko Surin in order to help to understand how reefs react to major disturbances. We found that the densities of coral recruits varied among years and study sites. In the year 2011, coral recruitments ranged between 0.18 ± 0.02 to 1.67 ± 0.07 recruits per m2 for 10 study sites. While in 2012, the monitoring revealed a range between 0.96 ± 0.16 and 2.19 ± 0.21 recruits per m2 from 5 study sites. Fungia, Acropora, Porites and Favites were the dominant groups of coral recruits. In terms substrate forms, they were significant differences between sampling years but the preferential dominant substrate forms did not differ. The Acropora recruits at Ko Torinla showed normal distributions of size class during the two periods. Their ranges in 2011 and 2012 were 4-30 and 13-54 mm, respectively. Six species of Acropora recruits, i.e. Acropora intermedia, A. nasuta, A. cerealis, A. subulata, A. muricata and A. latistella were found. They showed diverse growth rates due to the spatial distribution of 2.11 ± 0.59 to 7.47 ± 1.37 cm per year. This study provides useful data in terms of coral recruitment and recovery from degradation and disturbance, especially from temperature changes induced by coral bleaching. The findings suggest that there is the possibility for coral recovery around Mu Ko Surin following the 2010 bleaching event.

  8. A first endeavour in restoring denuded, post-bleached reefs in Tanzania

    NASA Astrophysics Data System (ADS)

    Mbije, Nsajigwa E.; Spanier, Ehud; Rinkevich, Baruch

    2013-08-01

    The worldwide decline in coral reefs has prompted a search for effective restoration protocols. We transplanted 6912 and 7110 corals (Acropora muricata, Acropora nasuta, Acropora hemprichi, Pocillopora verrucosa, Porites cylindrica, Millepora sp.) in Changuu, Zanzibar and Kitutia, Mafia, Tanzanian reefs that suffered in 1998 from a massive coral bleaching incident, causing a wide spread coral death. No sign for natural recovery has been recorded thereafter. In each site, we randomly set up 12 plots (36 m2 each), of which three were transplanted with a mix of three Acropora spp. (Treatment 1, T1), three with a mix of all six scleractinian species (T2), and six served as controls. Within one month of transplantation, an outbreak of Acanthaster planci in Changuu caused mortality at 50%. One year survival of transplants in T1 and T2 at Kitutia reached 66.4% and 62.5% respectively, significantly higher than at Changuu; an outcome recorded through species-by-species comparisons on four species only (P. verrucosa, P. cylindrica, A. muricata, A. nasuta). After one year no significant difference was documented in ecological volumes (EV) between T1 and T2 in stark contrast to the among species comparisons in T1, at each site. A within treatment one-way ANOSIM comparison for fish assemblage structures performed between the first and last three months of the transplantation year (Kitutia reef) revealed strong separation (T1, Global R = 0.743, P < 0.001; T2, R = 0.445, P < 0.001 and T3, R = 0.694, P < 0.001) while the same treatment revealed weak separation at Changuu site T1 (R = 0.035, P > 0.262) and T2 plots (R = 0.119, P < 0.043). Similarly, one-way ANOSIM done on the initial and last 3-month periods on invertebrates' community composition (at all sites, except T1 of Changuu reef), showed no significant difference between community composition at both ends of the sampling period. Altogether, transplantation cost (US$0.19/colony) suggested that large scale transplantation is

  9. Tropical coastal habitats as surrogates of fish community structure, grazing, and fisheries value.

    PubMed

    Harborne, Alastair R; Mumby, Peter J; Kappel, Carrie V; Dahlgren, Craig P; Micheli, Fiorenza; Holmes, Katherine E; Brumbaugh, Daniel R

    2008-10-01

    Habitat maps are frequently invoked as surrogates of biodiversity to aid the design of networks of marine reserves. Maps are used to maximize habitat heterogeneity in reserves because this is likely to maximize the number of species protected. However, the technique's efficacy is limited by intra-habitat variability in the species present and their abundances. Although communities are expected to vary among patches of the same habitat, this variability is poorly documented and rarely incorporated into reserve planning. To examine intra-habitat variability in coral-reef fishes, we generated a data set from eight tropical coastal habitats and six islands in the Bahamian archipelago using underwater visual censuses. Firstly, we provide further support for habitat heterogeneity as a surrogate of biodiversity as each predefined habitat type supported a distinct assemblage of fishes. Intra-habitat variability in fish community structure at scales of hundreds of kilometers (among islands) was significant in at least 75% of the habitats studied, depending on whether presence/absence, density, or biomass data were used. Intra-habitat variability was positively correlated with the mean number of species in that habitat when density and biomass data were used. Such relationships provide a proxy for the assessment of intra-habitat variability when detailed quantitative data are scarce. Intra-habitat variability was examined in more detail for one habitat (forereefs visually dominated by Montastraea corals). Variability in community structure among islands was driven by small, demersal families (e.g., territorial pomacentrid and labrid fishes). Finally, we examined the ecological and economic significance of intra-habitat variability in fish assemblages on Montastraea reefs by identifying how this variability affects the composition and abundances of fishes in different functional groups, the key ecosystem process of parrotfish grazing, and the ecosystem service of value of

  10. Coral Skeleton Density Banding: Biotic Response to Changes in Sea Surface Temperature

    NASA Astrophysics Data System (ADS)

    Hill, C. A.; Sivaguru, M.; Fried, G. A.; Fouke, B. W.

    2010-12-01

    Density bands in the CaCO3 (aragonite) skeleton of scleractinian corals are commonly used as chronometers, where crystalline couplets of high and low density bands represent the span of one year. Isotopic analysis of these density bands provides a sensitive reconstructive tool for paleoclimatology and paleoecology. However, the detailed biotic mechanisms controlling coral skeleton aragonite nucleation and crystallization events and resulting skeletal growth rate remain uncertain. The coral tissue organic matrix, composed of macromolecules secreted by the calicoblastic ectoderm, is closely associated with skeletal precipitation and is itself incorporated into the skeleton. We postulate that density banding is primarily controlled by changes in the rate of aragonite crystal precipitation mediated by the coral holobiont response to changes in sea surface temperature (SST). To test this hypothesis, data were collected from coral skeleton-tissue biopsies (2.5 cm in diameter) extracted from four species of Montastraea growing on the fringing reef tract of Curacao, Netherlands Antilles. Annual mean variation in SST on Curacao range from 29o in mid-September to 26o C in late February. Samples were collected at strategic time periods spanning the 3o C annual variations in SST. Our nanometer-scale optical analyses of skeletal morphology have revealed consistent changes between high- and low-skeletal density bands, resulting in an 11% increase in the volume of aragonite precipitated in high-density skeletal bands. The re-localization and/or change in abundance of mucus, carbonic anhydrase (a molecule that catalyzes the hydration of carbon dioxide), calmodulin (a calcium-binding protein) and the change in density of gastrodermal symbiotic dinoflagellates has permitted estimates of seasonally-fluctuating carbon allocation by the coral holobiont in response to changing environmental conditions. This digital reconstruction of over 2000 images of one-micron-thick histological

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  12. Species–specific interactions between algal endosymbionts and coral hosts define their bleaching response to heat and light stress

    PubMed Central

    Abrego, David; Ulstrup, Karin E; Willis, Bette L; van Oppen, Madeleine J.H

    2008-01-01

    The impacts of warming seas on the frequency and severity of bleaching events are well documented, but the potential for different Symbiodinium types to enhance the physiological tolerance of reef corals is not well understood. Here we compare the functionality and physiological properties of juvenile corals when experimentally infected with one of two homologous Symbiodinium types and exposed to combined heat and light stress. A suite of physiological indicators including chlorophyll a fluorescence, oxygen production and respiration, as well as pigment concentration consistently demonstrated lower metabolic costs and enhanced physiological tolerance of Acropora tenuis juveniles when hosting Symbiodinium type C1 compared with type D. In other studies, the same D-type has been shown to confer higher thermal tolerance than both C2 in adults and C1 in juveniles of the closely related species Acropora millepora. Our results challenge speculations that associations with type D are universally most robust to thermal stress. Although the heat tolerance of corals may be contingent on the Symbiodinium strain in hospite, our results highlight the complexity of interactions between symbiotic partners and a potential role for host factors in determining the physiological performance of reef corals. PMID:18577506

  13. Remote coral reefs can sustain high growth potential and may match future sea-level trends

    PubMed Central

    Perry, Chris T.; Murphy, Gary N.; Graham, Nicholas A. J.; Wilson, Shaun K.; Januchowski-Hartley, Fraser A.; East, Holly K.

    2015-01-01

    Climate-induced disturbances are contributing to rapid, global-scale changes in coral reef ecology. As a consequence, reef carbonate budgets are declining, threatening reef growth potential and thus capacity to track rising sea-levels. Whether disturbed reefs can recover their growth potential and how rapidly, are thus critical research questions. Here we address these questions by measuring the carbonate budgets of 28 reefs across the Chagos Archipelago (Indian Ocean) which, while geographically remote and largely isolated from compounding human impacts, experienced severe (>90%) coral mortality during the 1998 warming event. Coral communities on most reefs recovered rapidly and we show that carbonate budgets in 2015 average +3.7 G (G = kg CaCO3 m−2 yr−1). Most significantly the production rates on Acropora-dominated reefs, the corals most severely impacted in 1998, averaged +8.4 G by 2015, comparable with estimates under pre-human (Holocene) disturbance conditions. These positive budgets are reflected in high reef growth rates (4.2 mm yr−1) on Acropora-dominated reefs, demonstrating that carbonate budgets on these remote reefs have recovered rapidly from major climate-driven disturbances. Critically, these reefs retain the capacity to grow at rates exceeding measured regional mid-late Holocene and 20th century sea-level rise, and close to IPCC sea-level rise projections through to 2100. PMID:26669758

  14. Species-specific interactions between algal endosymbionts and coral hosts define their bleaching response to heat and light stress.

    PubMed

    Abrego, David; Ulstrup, Karin E; Willis, Bette L; van Oppen, Madeleine J H

    2008-10-01

    The impacts of warming seas on the frequency and severity of bleaching events are well documented, but the potential for different Symbiodinium types to enhance the physiological tolerance of reef corals is not well understood. Here we compare the functionality and physiological properties of juvenile corals when experimentally infected with one of two homologous Symbiodinium types and exposed to combined heat and light stress. A suite of physiological indicators including chlorophyll a fluorescence, oxygen production and respiration, as well as pigment concentration consistently demonstrated lower metabolic costs and enhanced physiological tolerance of Acropora tenuis juveniles when hosting Symbiodinium type C1 compared with type D. In other studies, the same D-type has been shown to confer higher thermal tolerance than both C2 in adults and C1 in juveniles of the closely related species Acropora millepora. Our results challenge speculations that associations with type D are universally most robust to thermal stress. Although the heat tolerance of corals may be contingent on the Symbiodinium strain in hospite, our results highlight the complexity of interactions between symbiotic partners and a potential role for host factors in determining the physiological performance of reef corals.

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

    PubMed

    Browne, N K

    2012-06-01

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

  16. DMSP in Corals and Benthic Algae from the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Broadbent, A. D.; Jones, G. B.; Jones, R. J.

    2002-10-01

    In this study the first measurements of DMSP in six species of corals and ten species of benthic algae collected from four coral reefs in the Great Barrier Reef are reported, together with DMSP measurements made on cultured zooxanthellae. Concentrations ranged from 21 to 3831 (mean=743) fmol DMSP zooxanthellae -1 in corals, 0·16 to 2·96 nmol DMSP cm -2 (mean=90) for benthic macroalgae, and 48-285 fmol DMSP zooxanthellae -1 (mean=153) for cultured zooxanthellae. The highest concentrations of DMSP in corals occurred in Acropora formosa (mean=371 fmol DMSP zooxanthellae -1) and Acropora palifera (mean=3341 fmol DMSP zooxanthellae -1) with concentrations in A. palifera the highest DMSP concentrations reported in corals examined to date. As well as inter-specific differences in DMSP, intra-specific variation was also observed. Adjacent colonies of A. formosa that are known to have different thermal bleaching thresholds and morphologically distinct zooxanthellae, were also observed to have different DMSP concentrations, with the zooxanthellae in the colony that bleached containing DMSP at an average concentration of 436 fmol zooxanthellae -1, whilst the non-bleaching colony contained DMSP at an average concentration of 171 fmol zooxanthellae -1. The results of the present study have been used to calculate the area normalized DMSP concentrations in benthic algae (mean=0·015 mmol m -2) and corals (mean=2·22 mmol m -2) from the GBR. This data indicates that benthic algae and corals are a significant reservoir of DMSP in GBR waters.

  17. A unique coral biomineralization pattern has resisted 40 million years of major ocean chemistry change.

    PubMed

    Stolarski, Jarosław; Bosellini, Francesca R; Wallace, Carden C; Gothmann, Anne M; Mazur, Maciej; Domart-Coulon, Isabelle; Gutner-Hoch, Eldad; Neuser, Rolf D; Levy, Oren; Shemesh, Aldo; Meibom, Anders

    2016-01-01

    Today coral reefs are threatened by changes to seawater conditions associated with rapid anthropogenic global climate change. Yet, since the Cenozoic, these organisms have experienced major fluctuations in atmospheric CO2 levels (from greenhouse conditions of high pCO2 in the Eocene to low pCO2 ice-house conditions in the Oligocene-Miocene) and a dramatically changing ocean Mg/Ca ratio. Here we show that the most diverse, widespread, and abundant reef-building coral genus Acropora (20 morphological groups and 150 living species) has not only survived these environmental changes, but has maintained its distinct skeletal biomineralization pattern for at least 40 My: Well-preserved fossil Acropora skeletons from the Eocene, Oligocene, and Miocene show ultra-structures indistinguishable from those of extant representatives of the genus and their aragonitic skeleton Mg/Ca ratios trace the inferred ocean Mg/Ca ratio precisely since the Eocene. Therefore, among marine biogenic carbonate fossils, well-preserved acroporid skeletons represent material with very high potential for reconstruction of ancient ocean chemistry. PMID:27302371

  18. A unique coral biomineralization pattern has resisted 40 million years of major ocean chemistry change

    NASA Astrophysics Data System (ADS)

    Stolarski, Jarosław; Bosellini, Francesca R.; Wallace, Carden C.; Gothmann, Anne M.; Mazur, Maciej; Domart-Coulon, Isabelle; Gutner-Hoch, Eldad; Neuser, Rolf D.; Levy, Oren; Shemesh, Aldo; Meibom, Anders

    2016-06-01

    Today coral reefs are threatened by changes to seawater conditions associated with rapid anthropogenic global climate change. Yet, since the Cenozoic, these organisms have experienced major fluctuations in atmospheric CO2 levels (from greenhouse conditions of high pCO2 in the Eocene to low pCO2 ice-house conditions in the Oligocene-Miocene) and a dramatically changing ocean Mg/Ca ratio. Here we show that the most diverse, widespread, and abundant reef-building coral genus Acropora (20 morphological groups and 150 living species) has not only survived these environmental changes, but has maintained its distinct skeletal biomineralization pattern for at least 40 My: Well-preserved fossil Acropora skeletons from the Eocene, Oligocene, and Miocene show ultra-structures indistinguishable from those of extant representatives of the genus and their aragonitic skeleton Mg/Ca ratios trace the inferred ocean Mg/Ca ratio precisely since the Eocene. Therefore, among marine biogenic carbonate fossils, well-preserved acroporid skeletons represent material with very high potential for reconstruction of ancient ocean chemistry.

  19. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    PubMed Central

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-01-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events. PMID:26627576

  20. Stable and sporadic symbiotic communities of coral and algal holobionts

    PubMed Central

    Hester, Eric R; Barott, Katie L; Nulton, Jim; Vermeij, Mark JA; Rohwer, Forest L

    2016-01-01

    Coral and algal holobionts are assemblages of macroorganisms and microorganisms, including viruses, Bacteria, Archaea, protists and fungi. Despite a decade of research, it remains unclear whether these associations are spatial–temporally stable or species-specific. We hypothesized that conflicting interpretations of the data arise from high noise associated with sporadic microbial symbionts overwhelming signatures of stable holobiont members. To test this hypothesis, the bacterial communities associated with three coral species (Acropora rosaria, Acropora hyacinthus and Porites lutea) and two algal guilds (crustose coralline algae and turf algae) from 131 samples were analyzed using a novel statistical approach termed the Abundance-Ubiquity (AU) test. The AU test determines whether a given bacterial species would be present given additional sampling effort (that is, stable) versus those species that are sporadically associated with a sample. Using the AU test, we show that coral and algal holobionts have a high-diversity group of stable symbionts. Stable symbionts are not exclusive to one species of coral or algae. No single bacterial species was ubiquitously associated with one host, showing that there is not strict heredity of the microbiome. In addition to the stable symbionts, there was a low-diversity community of sporadic symbionts whose abundance varied widely across individual holobionts of the same species. Identification of these two symbiont communities supports the holobiont model and calls into question the hologenome theory of evolution. PMID:26555246

  1. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    NASA Astrophysics Data System (ADS)

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-12-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  2. Remote coral reefs can sustain high growth potential and may match future sea-level trends.

    PubMed

    Perry, Chris T; Murphy, Gary N; Graham, Nicholas A J; Wilson, Shaun K; Januchowski-Hartley, Fraser A; East, Holly K

    2015-12-16

    Climate-induced disturbances are contributing to rapid, global-scale changes in coral reef ecology. As a consequence, reef carbonate budgets are declining, threatening reef growth potential and thus capacity to track rising sea-levels. Whether disturbed reefs can recover their growth potential and how rapidly, are thus critical research questions. Here we address these questions by measuring the carbonate budgets of 28 reefs across the Chagos Archipelago (Indian Ocean) which, while geographically remote and largely isolated from compounding human impacts, experienced severe (>90%) coral mortality during the 1998 warming event. Coral communities on most reefs recovered rapidly and we show that carbonate budgets in 2015 average +3.7 G (G = kg CaCO3 m(-2) yr(-1)). Most significantly the production rates on Acropora-dominated reefs, the corals most severely impacted in 1998, averaged +8.4 G by 2015, comparable with estimates under pre-human (Holocene) disturbance conditions. These positive budgets are reflected in high reef growth rates (4.2 mm yr(-1)) on Acropora-dominated reefs, demonstrating that carbonate budgets on these remote reefs have recovered rapidly from major climate-driven disturbances. Critically, these reefs retain the capacity to grow at rates exceeding measured regional mid-late Holocene and 20th century sea-level rise, and close to IPCC sea-level rise projections through to 2100.

  3. 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

    NASA Astrophysics Data System (ADS)

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

    2007-09-01

    Reef corals form associations with an array of genetically and physiologically distinct endosymbionts from the genus Symbiodinium. Some corals harbor different clades of symbionts simultaneously, and over time the relative abundances of these clades may change through a process called symbiont shuffling. It is hypothesized that this process provides a mechanism for corals to respond to environmental threats such as global warming. However, only a minority of coral species have been found to harbor more than one symbiont clade simultaneously and the current view is that the potential for symbiont shuffling is limited. Using a newly developed real-time PCR assay, this paper demonstrates that previous studies have underestimated the presence of background symbionts because of the low sensitivity of the techniques used. The assay used here targets the multi-copy rDNA ITS1 region and is able to detect Symbiodinium clades C and D with >100-fold higher sensitivity compared to conventional techniques. Technical considerations relating to intragenomic variation, estimating copy number and non-symbiotic contamination are discussed. Eighty-two colonies from four common scleractinian species ( Acropora millepora, Acropora tenuis, Stylophora pistillata and Turbinaria reniformis) and 11 locations on the Great Barrier Reef were tested for background Symbiodinium clades. Although these colonies had been previously identified as harboring only a single clade based on SSCP analyses, background clades were detected in 78% of the samples, indicating that the potential for symbiont shuffling may be much larger than currently thought.

  4. Coral diseases are major contributors to coral mortality in Shingle Island, Gulf of Mannar, southeastern India.

    PubMed

    Thinesh, T; Diraviya Raj, K; Mathews, G; Patterson Edward, J K

    2013-09-24

    The present study reports coral mortality, driven primarily by coral diseases, around Shingle Island, Gulf of Mannar (GOM), Indian Ocean. In total, 2910 colonies were permanently monitored to assess the incidence of coral diseases and consequent mortality for 2 yr. Four types of lesions consistent with white band disease (WBD), black disease (BD), white plaque disease (WPD), and pink spot disease (PSD) were recorded from 4 coral genera: Montipora, Pocillopora, Acropora, and Porites. Porites were affected by 2 disease types, while the other 3 genera were affected by only 1 disease type. Overall disease prevalence increased from 8% (n = 233 colonies) to 41.9% (n = 1219) over the 2 yr study period. BD caused an unprecedented 100% mortality in Pocillopora, followed by 20.4 and 13.1% mortality from WBD in Montipora and Acropora, respectively. Mean disease progression rates of 0.8 ± 1.0 and 0.6 ± 0.5 cm mo-1 over live coral colonies were observed for BD and WBD. Significant correlations between temperature and disease progression were observed for BD (r = 0.86, R2 = 0.75, p < 0.001) and WBD (R2 = 0.76, p < 0.001). This study revealed the increasing trend of disease prevalence and progression of disease over live coral in a relatively limited study area; further study should investigate the status of the entire coral reef in the GOM and the role of diseases in reef dynamics. PMID:24062554

  5. Metal levels associated with tin dredging and smelting and their effect upon intertidal reef flats at ko phuket, Thailand

    NASA Astrophysics Data System (ADS)

    Brown, B. E.; Holley, M. C.

    1982-10-01

    Reef flats in the vicinity of tin dredging and smelting activities around the Laem Pan Wah peninsula, Phuket, and been quantitatively surveyed. the diversity of corals on all intertidal reefs was low (≏10 genera), the dominant genera being Porites, Montipora, Acropora and Platygyra. Two basic types of reef can be discerned, one dominated by Porites lutea and faviid species and the other by Montipora ramosa and Acropora aspera, reef type apparently being governed by the degree of exposure to water movement. Other natural factors affecting coral cover included freshwater run off, considerable sedimentation, and aerial exposure for 2 3 h each day. Heavy metal concentrations in invertebrate species such as the oyster Saccostrea, the bivalve Isognomon, and in the alga Padina reflected elevated metal levels at all sites when compared with controls (Figs. 8 and 9). In particular, levels of metals were considerably elevated in molluscs taken from the reef below the tin smelter. Interestingly, dead coral cover on this reef, although high, was not significantly different from values observed on reefs several kilometres away from the smelter, which were not apparently under the influence of such increased metal loads (Fig. 2). No elevation in metal concentrations in coral tissue or skeleton was evident at any site. It would appear, then, that these intertidal coral species are not obviously affected by the levels of metals discharged at the smelter site.

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

    PubMed

    Browne, N K

    2012-06-01

    Coral growth rates (linear extension, density, calcification rates) of three fast-growing corals (Acropora, Montipora, Turbinaria) were studied in situ on Middle Reef, an inshore reef located on the central Great Barrier Reef (GBR), to assess the influence of changing environmental conditions on coral condition and reef growth. Middle Reef is subjected to both local (e.g. high sediment loads) and global (e.g. coral bleaching) disturbance events, usually associated with reduced coral growth. Results indicated, however, that Acropora growth rates (mean linear extension = 6.3 cm/year) were comparable to those measured at similar depths on offshore reefs on the GBR. Montipora linear extension (2.9 cm/year) was greater than estimates available from both clear-water and turbid reefs, and Turbinaria's dense skeleton (1.3 g/cm(3)) may be more resilient to physical damage as ocean pH falls. Coral growth was found to vary between reef habitats due to spatial differences in water motion and sediment dynamics, and temporally with lower calcification rates during the summer months when SSTs (monthly average 29 °C) and rainfall (monthly total >500 mm) were high. In summary, corals on Middle Reef are robust and resilient to their marginal environmental conditions, but are susceptible to anthropogenic disturbances during the summer months. PMID:22391236

  7. Variability in microbial community composition and function between different niches within a coral reef.

    PubMed

    Tout, Jessica; Jeffries, Thomas C; Webster, Nicole S; Stocker, Roman; Ralph, Peter J; Seymour, Justin R

    2014-04-01

    To explore how microbial community composition and function varies within a coral reef ecosystem, we performed metagenomic sequencing of seawater from four niches across Heron Island Reef, within the Great Barrier Reef. Metagenomes were sequenced from seawater samples associated with (1) the surface of the coral species Acropora palifera, (2) the surface of the coral species Acropora aspera, (3) the sandy substrate within the reef lagoon and (4) open water, outside of the reef crest. Microbial composition and metabolic function differed substantially between the four niches. The taxonomic profile showed a clear shift from an oligotroph-dominated community (e.g. SAR11, Prochlorococcus, Synechococcus) in the open water and sandy substrate niches, to a community characterised by an increased frequency of copiotrophic bacteria (e.g. Vibrio, Pseudoalteromonas, Alteromonas) in the coral seawater niches. The metabolic potential of the four microbial assemblages also displayed significant differences, with the open water and sandy substrate niches dominated by genes associated with core house-keeping processes such as amino acid, carbohydrate and protein metabolism as well as DNA and RNA synthesis and metabolism. In contrast, the coral surface seawater metagenomes had an enhanced frequency of genes associated with dynamic processes including motility and chemotaxis, regulation and cell signalling. These findings demonstrate that the composition and function of microbial communities are highly variable between niches within coral reef ecosystems and that coral reefs host heterogeneous microbial communities that are likely shaped by habitat structure, presence of animal hosts and local biogeochemical conditions.

  8. Holocene initiation and development of New Caledonian fringing reefs, SW Pacific

    NASA Astrophysics Data System (ADS)

    Cabioch, G.; Montaggioni, L. F.; Faure, G.

    1995-09-01

    The analysis of 8 selected cores through fringing reefs in New Caledonia reveals that accretion in the Holocene has been less than 6 m. The cores exhibit three main facies: branching coral ( Acropora, dominantly), massive coral heads ( Porites, mainly) and coral sand/ rubble, principally made up of acroporid fragments. Subordinate facies are composed of coralline algae and alcyonarian spiculite. The initiation of growth varies according to location. The southern reefs (i.e. early settled reefs) generally began to grow first, prior to 5000 y BP. The northern structures (i.e. more recently settled reefs) are younger, occurring after 4200 y BP. This retardation could be ascribed to differences in local physical conditions (nature of substrate, wave energy). Vertical accretion rates were generally higher in areas of lower energy (3.25 6.4 mm·y-1) versus those exposed to higher energy conditions (1.4 3.1 mm·y-1). Vertical development through time was accompanied by changes in composition of biological assemblages which reflect changes in hydrodynamics. The basal Acropora-dominated facies was replaced upwards by a Porites-dominated framework. The New Caledonian fringing reefs reached the sea surface generally between 5000 and 2500 y BP after the stabilization of sea level. Hence all of these reefs can be classified as catch-up reefs.

  9. Microbial aggregates within tissues infect a diversity of corals throughout the Indo-Pacific

    USGS Publications Warehouse

    Work, Thierry M.; Aeby, Greta S.

    2014-01-01

    Coral reefs are highly diverse ecosystems where symbioses play a pivotal role. Corals contain cell-associated microbial aggregates (CAMA), yet little is known about how widespread they are among coral species or the nature of the symbiotic relationship. Using histology, we found CAMA within 24 species of corals from 6 genera from Hawaii, American Samoa, Palmyra, Johnston Atoll, Guam, and Australia. Prevalence (%) of infection varied among coral genera: Acropora, Porites, and Pocillopora were commonly infected whereas Montipora were not. Acropora from the Western Pacific were significantly more likely to be infected with CAMA than those from the Central Pacific, whereas the reverse was true for Porites. Compared with apparently healthy colonies, tissues from diseased colonies were significantly more likely to have both surface and basal body walls infected. The close association of CAMA with host cells in numerous species of apparently healthy corals and lack of associated cell pathology reveals an intimate agent-host association. Furthermore, CAMA are Gram negative and in some corals may be related to chlamydia or rickettsia. We propose that CAMA in adult corals are facultative secondary symbionts that could play an important ecological role in some dominant coral genera in the Indo-Pacific. CAMA are important in the life histories of other animals, and more work is needed to understand their role in the distribution, evolution, physiology, and immunology of reef corals.

  10. Screening by coral green fluorescent protein (GFP)-like chromoproteins supports a role in photoprotection of zooxanthellae

    NASA Astrophysics Data System (ADS)

    Smith, E. G.; D'Angelo, C.; Salih, A.; Wiedenmann, J.

    2013-06-01

    Green fluorescent protein (GFP)-like pigments are responsible for the vivid colouration of many reef-building corals and have been proposed to act as photoprotectants. Their role remains controversial because the functional mechanism has not been elucidated. We provide direct evidence to support a photoprotective role of the non-fluorescent chromoproteins (CPs) that form a biochemically and photophysically distinct group of GFP-like proteins. Based on observations of Acropora nobilis from the Great Barrier Reef, we explored the photoprotective role of CPs by analysing five coral species under controlled conditions. In vitro and in hospite analyses of chlorophyll excitation demonstrate that screening by CPs leads to a reduction in chlorophyll excitation corresponding to the spectral properties of the specific CPs present in the coral tissues. Between 562 and 586 nm, the CPs maximal absorption range, there was an up to 50 % reduction of chlorophyll excitation. The screening was consistent for established and regenerating tissue and amongst symbiont clades A, C and D. Moreover, among two differently pigmented morphs of Acropora valida grown under identical light conditions and hosting subclade type C3 symbionts, high CP expression correlated with reduced photodamage under acute light stress.

  11. The promiscuous larvae: flexibility in the establishment of symbiosis in corals

    NASA Astrophysics Data System (ADS)

    Cumbo, V. R.; Baird, A. H.; van Oppen, M. J. H.

    2013-03-01

    Coral reefs thrive in part because of the symbiotic partnership between corals and Symbiodinium. While this partnership is one of the keys to the success of coral reef ecosystems, surprisingly little is known about many aspects of coral symbiosis, in particular the establishment and development of symbiosis in host species that acquire symbionts anew in each generation. More specifically, the point at which symbiosis is established (i.e., larva vs. juvenile) remains uncertain, as does the source of free-living Symbiodinium in the environment. In addition, the capacity of host and symbiont to form novel combinations is unknown. To explore patterns of initial association between host and symbiont, larvae of two species of Acropora were exposed to sediment collected from three locations on the Great Barrier Reef. A high proportion of larvae established symbiosis shortly after contact with sediments, and Acropora larvae were promiscuous, taking up multiple types of Symbiodinium. The Symbiodinium types acquired from the sediments reflected the symbiont assemblage within a wide range of cnidarian hosts at each of the three sites, suggesting potential regional differences in the free-living Symbiodinium assemblage. Coral larvae clearly have the capacity to take up Symbiodinium prior to settlement, and sediment is a likely source. Promiscuous larvae allow species to associate with Symbiodinium appropriate for potentially novel environments that may be experienced following dispersal.

  12. Biotic Control of Skeletal Growth by Scleractinian Corals in Aragonite–Calcite Seas

    PubMed Central

    Higuchi, Tomihiko; Fujimura, Hiroyuki; Yuyama, Ikuko; Harii, Saki; Agostini, Sylvain; Oomori, Tamotsu

    2014-01-01

    Modern scleractinian coral skeletons are commonly composed of aragonite, the orthorhombic form of CaCO3. Under certain conditions, modern corals produce calcite as a secondary precipitate to fill pore space. However, coral construction of primary skeletons from calcite has yet to be demonstrated. We report a calcitic primary skeleton produced by the modern scleractinian coral Acropora tenuis. When uncalcified juveniles were incubated from the larval stage in seawater with low mMg/Ca levels, the juveniles constructed calcitic crystals in parts of the primary skeleton such as the septa; the deposits were observable under Raman microscopy. Using scanning electron microscopy, we observed different crystal morphologies of aragonite and calcite in a single juvenile skeleton. Quantitative analysis using X-ray diffraction showed that the majority of the skeleton was composed of aragonite even though we had exposed the juveniles to manipulated seawater before their initial crystal nucleation and growth processes. Our results indicate that the modern scleractinian coral Acropora mainly produces aragonite skeletons in both aragonite and calcite seas, but also has the ability to use calcite for part of its skeletal growth when incubated in calcite seas. PMID:24609012

  13. Stable and sporadic symbiotic communities of coral and algal holobionts.

    PubMed

    Hester, Eric R; Barott, Katie L; Nulton, Jim; Vermeij, Mark Ja; Rohwer, Forest L

    2016-05-01

    Coral and algal holobionts are assemblages of macroorganisms and microorganisms, including viruses, Bacteria, Archaea, protists and fungi. Despite a decade of research, it remains unclear whether these associations are spatial-temporally stable or species-specific. We hypothesized that conflicting interpretations of the data arise from high noise associated with sporadic microbial symbionts overwhelming signatures of stable holobiont members. To test this hypothesis, the bacterial communities associated with three coral species (Acropora rosaria, Acropora hyacinthus and Porites lutea) and two algal guilds (crustose coralline algae and turf algae) from 131 samples were analyzed using a novel statistical approach termed the Abundance-Ubiquity (AU) test. The AU test determines whether a given bacterial species would be present given additional sampling effort (that is, stable) versus those species that are sporadically associated with a sample. Using the AU test, we show that coral and algal holobionts have a high-diversity group of stable symbionts. Stable symbionts are not exclusive to one species of coral or algae. No single bacterial species was ubiquitously associated with one host, showing that there is not strict heredity of the microbiome. In addition to the stable symbionts, there was a low-diversity community of sporadic symbionts whose abundance varied widely across individual holobionts of the same species. Identification of these two symbiont communities supports the holobiont model and calls into question the hologenome theory of evolution.

  14. Recruitment patterns of scleractinian corals in an isolated sub-tropical reef system

    NASA Astrophysics Data System (ADS)

    Harriott, V. J.

    1992-12-01

    The density of recruits of scleractinian corals on settlement plates at Lord Howe Island, a small isolated sub-tropical island 630 km off the Australian coastline, was within the range of values reported for comparable studies on the Great Barrier Reef. However, there was a difference in the relative abundance of taxonomic groups, with recruitment at Lord Howe Island during the summer of 1990/91 dominated by corals from the Family Pocilloporidae, Family Poritidae, and sub-genus Acropora (Isopora) (in order of abundance). By contrast, on the Great Barrier Reef, recruits are generally predominantly species from the Family Acroporidae (other than the Acropora (Isopora) group). Both the recruits and the established coral communities at Lord Howe Island are dominanted by corals which release brooded planulae, as opposed to the pattern of mass-spawning with external fertilisation more typical of Great Barrier Reef corals. I hypothesise that the release of brooded planulae would be advantageous in an isolated reef community because (a) brooded larvae can travel large distances and survive the journey to the isolated reef and/or (b) brooded larvae have a shorter period before they are competent to settle and are therefore more likely to be retained on the parental reef once a population has been established.

  15. Associational refuges among corals mediate impacts of a crown-of-thorns starfish Acanthaster planci outbreak. Indirect positive interactions in communities

    NASA Astrophysics Data System (ADS)

    Kayal, Mohsen; Lenihan, Hunter S.; Pau, Cédric; Penin, Lucie; Adjeroud, Mehdi

    2011-09-01

    Interactions among coral populations can moderate the impact of coral predator outbreaks, enhancing community resilience and recovery. This study used predator-exclusion cages and neighbour removals in a field experiment to test how indirect interactions between populations of three coral taxa, Acropora, Pocillopora, and Porites, influenced their survival during an outbreak of the crown-of-thorns starfish, Acanthaster planci, in Moorea, French Polynesia. High densities of corals enhanced survival by generating associational refuges: physical structures that impeded Acanthaster and protected corals, and by simple density-dependent prey dilution that reduced predation rates. Acanthaster showed feeding preferences, resulting in varying intensities of predation on corals, which (1) influenced the type and strength of the associational refuge among corals and (2) resulted in significant loss of the competitive dominants to the benefit of the competitive inferiors. The result was a set of indirect positive interactions (IPIs) that prevented Acanthaster from eradicating Acropora and may have enhanced Porites, a relatively weak competitor among corals. IPIs probably play a key role in many ecosystems, especially in coral reefs in which corals act as engineer species, to reduce impacts of perturbations and enhance community resilience. This study illustrates the importance of IPIs in community regulation with a new conceptual model.

  16. Seasonal monitoring of coral-algae interactions in fringing reefs of the Gulf of Aqaba, Northern Red Sea

    NASA Astrophysics Data System (ADS)

    Haas, A.; El-Zibdah, M.; Wild, C.

    2010-03-01

    This paper presents seasonal in situ monitoring data on benthic coverage and coral -algae interactions in high-latitude fringing reefs of the Northern Red Sea over a period of 19 months. More than 30% of all hermatypic corals were involved in interaction with benthic reef algae during winter compared to 17% during summer, but significant correlation between the occurrence of coral -algae interactions and monitored environmental factors such as temperature and inorganic nutrient availability was not detected. Between 5 and 10-m water depth, the macroalgae Caulerpa serrulata, Peyssonnelia capensis and filamentous turf algae represented almost 100% of the benthic algae involved in interaction with corals. Turf algae were most frequently (between 77 and 90% of all interactions) involved in interactions with hermatypic corals and caused most tissue damage to them. Maximum coral tissue loss of 0.75% day-1 was observed for Acropora-turf algae interaction during fall, while an equilibrium between both groups of organisms appeared during summer. Slow-growing massive corals were more resistant against negative algal influence than fast-growing branching corals. Branching corals of the genus Acropora partly exhibited a newly observed phenotypic plasticity mechanism, by development of a bulge towards the competing organism, when in interaction with algae. These findings may contribute to understand the dynamics of phase shifts in coral reefs by providing seasonally resolved in situ monitoring data on the abundance and the competitive dynamic of coral -algae interactions.

  17. Remote coral reefs can sustain high growth potential and may match future sea-level trends.

    PubMed

    Perry, Chris T; Murphy, Gary N; Graham, Nicholas A J; Wilson, Shaun K; Januchowski-Hartley, Fraser A; East, Holly K

    2015-01-01

    Climate-induced disturbances are contributing to rapid, global-scale changes in coral reef ecology. As a consequence, reef carbonate budgets are declining, threatening reef growth potential and thus capacity to track rising sea-levels. Whether disturbed reefs can recover their growth potential and how rapidly, are thus critical research questions. Here we address these questions by measuring the carbonate budgets of 28 reefs across the Chagos Archipelago (Indian Ocean) which, while geographically remote and largely isolated from compounding human impacts, experienced severe (>90%) coral mortality during the 1998 warming event. Coral communities on most reefs recovered rapidly and we show that carbonate budgets in 2015 average +3.7 G (G = kg CaCO3 m(-2) yr(-1)). Most significantly the production rates on Acropora-dominated reefs, the corals most severely impacted in 1998, averaged +8.4 G by 2015, comparable with estimates under pre-human (Holocene) disturbance conditions. These positive budgets are reflected in high reef growth rates (4.2 mm yr(-1)) on Acropora-dominated reefs, demonstrating that carbonate budgets on these remote reefs have recovered rapidly from major climate-driven disturbances. Critically, these reefs retain the capacity to grow at rates exceeding measured regional mid-late Holocene and 20th century sea-level rise, and close to IPCC sea-level rise projections through to 2100. PMID:26669758

  18. Highly infectious symbiont dominates initial uptake in coral juveniles.

    PubMed

    Abrego, David; VAN Oppen, Madeleine J H; Willis, Bette L

    2009-08-01

    The majority of reef-building corals acquire their obligate algal symbionts (Symbiodinium) from the environment. However, factors shaping the initial establishment of coral-algal symbioses, including parental effects, local environmental conditions and local availability of symbionts, are not well understood. This study monitored the uptake and maintenance of Symbiodinium in juveniles of two common corals, Acropora tenuis and Acropora millepora, that were reciprocally explanted between sites where adult colonies host different types of Symbiodinium. We found that coral juveniles were rapidly dominated by type D Symbiodinium, even though this type is not found in adult colonies (including the parental colonies) in four out of the five study populations. Furthermore, type D Symbiodinium was found in less than one-third of a wide range of coral species (n > 50) sampled at the two main study sites, suggesting that its dominance in the acroporid juveniles is not because it is the most abundant local endosymbiotic type. Moreover, dominance by type D was observed irrespective of the light intensity to which juveniles were exposed in a field study. In summary, despite its relatively low abundance in coral assemblages at the study sites and irrespective of the surrounding light environment, type D Symbiodinium is the main symbiont type initially acquired by juveniles of A. millepora and A. tenuis. We conclude that during early ontogeny in these corals, there are few barriers to the uptake of Symbiodinium types which differ from those found in parental colonies, resulting in dominance by a highly infectious and potentially opportunistic symbiont.

  19. A unique coral biomineralization pattern has resisted 40 million years of major ocean chemistry change

    PubMed Central

    Stolarski, Jarosław; Bosellini, Francesca R.; Wallace, Carden C.; Gothmann, Anne M.; Mazur, Maciej; Domart-Coulon, Isabelle; Gutner-Hoch, Eldad; Neuser, Rolf D.; Levy, Oren; Shemesh, Aldo; Meibom, Anders

    2016-01-01

    Today coral reefs are threatened by changes to seawater conditions associated with rapid anthropogenic global climate change. Yet, since the Cenozoic, these organisms have experienced major fluctuations in atmospheric CO2 levels (from greenhouse conditions of high pCO2 in the Eocene to low pCO2 ice-house conditions in the Oligocene-Miocene) and a dramatically changing ocean Mg/Ca ratio. Here we show that the most diverse, widespread, and abundant reef-building coral genus Acropora (20 morphological groups and 150 living species) has not only survived these environmental changes, but has maintained its distinct skeletal biomineralization pattern for at least 40 My: Well-preserved fossil Acropora skeletons from the Eocene, Oligocene, and Miocene show ultra-structures indistinguishable from those of extant representatives of the genus and their aragonitic skeleton Mg/Ca ratios trace the inferred ocean Mg/Ca ratio precisely since the Eocene. Therefore, among marine biogenic carbonate fossils, well-preserved acroporid skeletons represent material with very high potential for reconstruction of ancient ocean chemistry. PMID:27302371

  20. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment.

    PubMed

    Schoepf, Verena; Stat, Michael; Falter, James L; McCulloch, Malcolm T

    2015-01-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events. PMID:26627576

  1. Polyunsaturated fatty acids in various macroalgal species from north Atlantic and tropical seas

    PubMed Central

    2011-01-01

    Background In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. Methods The fatty acid (FA) composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum) and two from tropical seas (Caulerpa taxifolia, Sargassum natans) was determined using GCMS. Four independent replicates were taken from each seaweed species. Results Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs), were in the concentration range of 2-14 mg/g dry matter (DM), while total lipid content ranged from 7-45 mg/g DM. The n-9 FAs of the selected seaweeds accounted for 3%-56% of total FAs, n-6 FAs for 3%-32% and n-3 FAs for 8%-63%. Red and brown seaweeds contain arachidonic (C20:4, n-6) and/or eicosapentaenoic acids (EPA, C20:5, n-3), the latter being an important "fish" FA, as major PUFAs while in green seaweeds these values are low and mainly C16 FAs were found. A unique observation is the presence of another typical "fish" fatty acid, docosahexaenoic acid (DHA, C22:6, n-3) at ≈ 1 mg/g DM in S. natans. The n-6: n-3 ratio is in the range of 0.05-2.75 and in most cases below 1.0. Environmental effects on lipid-bound FA composition in seaweed species are discussed. Conclusion Marine macroalgae form a good, durable and virtually inexhaustible source for polyunsaturated fatty acids with an (n-6) FA: (n-3) FA ratio of about 1.0. This ratio is recommended by the World Health Organization to be less than 10 in order to prevent inflammatory, cardiovascular and nervous system disorders. Some marine macroalgal species, like P. palmata, contain high proportions of the "fish fatty acid" eicosapentaenoic acid (EPA, C20:5, n-3), while in S. natans also docosahexaenoic acid (DHA, C22:6, n-3) was

  2. Reef Endemism, Host Specificity and Temporal Stability in Populations of Symbiotic Dinoflagellates from Two Ecologically Dominant Caribbean Corals

    PubMed Central

    Thornhill, Daniel J.; Xiang, Yu; Fitt, William K.; Santos, Scott R.

    2009-01-01

    Background The dinoflagellate genus Symbiodinium forms symbioses with numerous protistan and invertebrate metazoan hosts. However, few data on symbiont genetic structure are available, hindering predictions of how these populations and their host associations will fair in the face of global climate change. Methodology/Principal Findings Here, Symbiodinium population structure from two of the Caribbean's ecologically dominant scleractinian corals, Montastraea faveolata and M. annularis, was examined. Tagged colonies on Florida Keys and Bahamian (i.e., Exuma Cays) reefs were sampled from 2003–2005 and their Symbiodinium diversity assessed via internal transcribed spacer 2 (ITS2) rDNA and three Symbiodinium Clade B-specific microsatellite loci. Generally, the majority of host individuals at a site harbored an identical Symbiodinium ITS2 “type” B1 microsatellite genotype. Notably, symbiont genotypes were largely reef endemic, suggesting a near absence of dispersal between populations. Relative to the Bahamas, sympatric M. faveolata and M. annularis in the Florida Keys harbored unique Symbiodinium populations, implying regional host specificity in these relationships. Furthermore, within-colony Symbiodinium population structure remained stable through time and environmental perturbation, including a prolonged bleaching event in 2005. Conclusions/Significance Taken together, the population-level endemism, specificity and stability exhibited by Symbiodinium raises concerns about the long-term adaptive capacity and persistence of these symbioses in an uncertain future of climate change. PMID:19603078