Mitochondrial and Nuclear Genes Suggest that Stony Corals Are Monophyletic but Most Families of Stony Corals Are Not (Order Scleractinia, Class Anthozoa, Phylum Cnidaria)

PubMed Central

Fukami, Hironobu; Chen, Chaolun Allen; Budd, Ann F.; Collins, Allen; Wallace, Carden; Chuang, Yao-Yang; Chen, Chienhsun; Dai, Chang-Feng; Iwao, Kenji; Sheppard, Charles; Knowlton, Nancy

2008-01-01

Modern hard corals (Class Hexacorallia; Order Scleractinia) are widely studied because of their fundamental role in reef building and their superb fossil record extending back to the Triassic. Nevertheless, interpretations of their evolutionary relationships have been in flux for over a decade. Recent analyses undermine the legitimacy of traditional suborders, families and genera, and suggest that a non-skeletal sister clade (Order Corallimorpharia) might be imbedded within the stony corals. However, these studies either sampled a relatively limited array of taxa or assembled trees from heterogeneous data sets. Here we provide a more comprehensive analysis of Scleractinia (127 species, 75 genera, 17 families) and various outgroups, based on two mitochondrial genes (cytochrome oxidase I, cytochrome b), with analyses of nuclear genes (ß-tubulin, ribosomal DNA) of a subset of taxa to test unexpected relationships. Eleven of 16 families were found to be polyphyletic. Strikingly, over one third of all families as conventionally defined contain representatives from the highly divergent “robust” and “complex” clades. However, the recent suggestion that corallimorpharians are true corals that have lost their skeletons was not upheld. Relationships were supported not only by mitochondrial and nuclear genes, but also often by morphological characters which had been ignored or never noted previously. The concordance of molecular characters and more carefully examined morphological characters suggests a future of greater taxonomic stability, as well as the potential to trace the evolutionary history of this ecologically important group using fossils. PMID:18795098

Mitochondrial and nuclear genes suggest that stony corals are monophyletic but most families of stony corals are not (Order Scleractinia, Class Anthozoa, Phylum Cnidaria).

PubMed

Fukami, Hironobu; Chen, Chaolun Allen; Budd, Ann F; Collins, Allen; Wallace, Carden; Chuang, Yao-Yang; Chen, Chienhsun; Dai, Chang-Feng; Iwao, Kenji; Sheppard, Charles; Knowlton, Nancy

2008-09-16

Modern hard corals (Class Hexacorallia; Order Scleractinia) are widely studied because of their fundamental role in reef building and their superb fossil record extending back to the Triassic. Nevertheless, interpretations of their evolutionary relationships have been in flux for over a decade. Recent analyses undermine the legitimacy of traditional suborders, families and genera, and suggest that a non-skeletal sister clade (Order Corallimorpharia) might be imbedded within the stony corals. However, these studies either sampled a relatively limited array of taxa or assembled trees from heterogeneous data sets. Here we provide a more comprehensive analysis of Scleractinia (127 species, 75 genera, 17 families) and various outgroups, based on two mitochondrial genes (cytochrome oxidase I, cytochrome b), with analyses of nuclear genes (ss-tubulin, ribosomal DNA) of a subset of taxa to test unexpected relationships. Eleven of 16 families were found to be polyphyletic. Strikingly, over one third of all families as conventionally defined contain representatives from the highly divergent "robust" and "complex" clades. However, the recent suggestion that corallimorpharians are true corals that have lost their skeletons was not upheld. Relationships were supported not only by mitochondrial and nuclear genes, but also often by morphological characters which had been ignored or never noted previously. The concordance of molecular characters and more carefully examined morphological characters suggests a future of greater taxonomic stability, as well as the potential to trace the evolutionary history of this ecologically important group using fossils.

Effects of environmental factors on C-type lectin recognition to zooxanthellae in the stony coral Pocillopora damicornis.

PubMed

Zhou, Zhi; Zhao, Shuimiao; Ni, Junyi; Su, Yilu; Wang, Lingui; Xu, Yanlai

2018-08-01

C-type lectin is a superfamily of Ca 2+ -dependent carbohydrate-recognition proteins that play significant roles in nonself-recognition and pathogen clearance. In the present study, a C-type lectin (PdC-Lectin) was chosen from stony coral Pocillopora damicornis to understand its recognition characteristics to zooxanthellae. PdC-Lectin protein contained a signal peptide and a carbohydrate-recognition domain with EPN motif in Ca 2+ -binding site 2. The PdC-Lectin recombinant protein was expressed and purified in vitro. The binding of PdC-Lectin protein to zooxanthellae was determined with western blotting method, and the bound protein to 10-10 5  cell mL -1 zooxanthellae was detectable in a concentration-dependent manner. Less PdC-Lectin protein binding to zooxanthellae was observed for the incubation at 36 °C than that at 26 °C. Furthermore, the PAMP recognition spectrum of PdC-Lectin protein was tested through surface plasmon resonance method, and it bound to LPS and Lipid A, but not to LTA, β-glucan, mannose or Poly (I:C). When PdC-Lectin protein was preincubated with LPS, there was less protein binding to zooxanthellae compared with that in non-preincubation group. These results collectively suggest that PdC-Lectin could recognize zooxanthellae, and the recognition could be repressed by high temperature and pathogenic bacteria, which would help to further understand the molecular mechanism of coral bleaching and the establishment of coral-zooxanthella symbiosis in the stony coral P. damicornis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rapid Assessment of Stony Coral Richness and Condition on Saba Bank, Netherlands Antilles

PubMed Central

McKenna, Sheila A.; Etnoyer, Peter

2010-01-01

The benthic habitats of Saba Bank (17°25′N, 63°30′W) are at risk from maritime traffic, especially oil tankers (e.g., anchoring). To mitigate this risk, information is needed on the biodiversity and location of habitats to develop a zone use plan. A rapid survey to document the biodiversity of macro-algae, sponges, corals and fishes was conducted. Here we report on the richness and condition of stony coral species at 18 select sites, and we test for the effects of bottom type, depth, and distance from platform edge. Species richness was visually assessed by roving scuba diver with voucher specimens of each species collected. Coral tissue was examined for bleaching and diseases. Thirty-three coral species were documented. There were no significant differences in coral composition among bottom types or depth classes (ANOSIM, P>0.05). There was a significant difference between sites (ANOSIM, P<0.05) near and far from the platform edge. The number of coral species observed ranged from zero and one in algal dominated habitats to 23 at a reef habitat on the southern edge of the Bank. Five reef sites had stands of Acropora cervicornis, a critically endangered species on the IUCN redlist. Bleaching was evident at 82% of the sites assessed with 43 colonies bleached. Only three coral colonies were observed to have disease. Combining our findings with that of other studies, a total of 43 species have been documented from Saba Bank. The coral assemblage on the bank is representative and typical of those found elsewhere in the Caribbean. Although our findings will help develop effective protection, more information is needed on Saba Bank to create a comprehensive zone use plan. Nevertheless, immediate action is warranted to protect the diverse coral reef habitats documented here, especially those containing A. cervicornis. PMID:20505771

Evolutionary and biogeographical implications of degraded LAGLIDADG endonuclease functionality and group I intron occurrence in stony corals (Scleractinia) and mushroom corals (Corallimorpharia).

PubMed

Celis, Juan Sebastián; Edgell, David R; Stelbrink, Björn; Wibberg, Daniel; Hauffe, Torsten; Blom, Jochen; Kalinowski, Jörn; Wilke, Thomas

2017-01-01

Group I introns and homing endonuclease genes (HEGs) are mobile genetic elements, capable of invading target sequences in intron-less genomes. LAGLIDADG HEGs are the largest family of endonucleases, playing a key role in the mobility of group I introns in a process known as 'homing'. Group I introns and HEGs are rare in metazoans, and can be mainly found inserted in the COXI gene of some sponges and cnidarians, including stony corals (Scleractinia) and mushroom corals (Corallimorpharia). Vertical and horizontal intron transfer mechanisms have been proposed as explanations for intron occurrence in cnidarians. However, the central role of LAGLIDADG motifs in intron mobility mechanisms remains poorly understood. To resolve questions regarding the evolutionary origin and distribution of group I introns and HEGs in Scleractinia and Corallimorpharia, we examined intron/HEGs sequences within a comprehensive phylogenetic framework. Analyses of LAGLIDADG motif conservation showed a high degree of degradation in complex Scleractinia and Corallimorpharia. Moreover, the two motifs lack the respective acidic residues necessary for metal-ion binding and catalysis, potentially impairing horizontal intron mobility. In contrast, both motifs are highly conserved within robust Scleractinia, indicating a fully functional endonuclease capable of promoting horizontal intron transference. A higher rate of non-synonymous substitutions (Ka) detected in the HEGs of complex Scleractinia and Corallimorpharia suggests degradation of the HEG, whereas lower Ka rates in robust Scleractinia are consistent with a scenario of purifying selection. Molecular-clock analyses and ancestral inference of intron type indicated an earlier intron insertion in complex Scleractinia and Corallimorpharia in comparison to robust Scleractinia. These findings suggest that the lack of horizontal intron transfers in the former two groups is related to an age-dependent degradation of the endonuclease activity. Moreover

STONY CORAL RAPID BIOASSESSMENT PROTOCOL

EPA Science Inventory

At a time when coral reefs worldwide are in the greatest decline of their known existence, and despite the enormous value of coral reef ecosystem services, there are relatively few tools available to resource managers to offset the growing impact of human activities. However, we...

Airborne lidar sensing of massive stony coral colonies on patch reefs in the northern Florida reef tract

USGS Publications Warehouse

Brock, J.C.; Wright, C.W.; Kuffner, I.B.; Hernandez, R.; Thompson, P.

2006-01-01

In this study we examined the ability of the NASA Experimental Advanced Airborne Research Lidar (EAARL) to discriminate cluster zones of massive stony coral colonies on northern Florida reef tract (NFRT) patch reefs based on their topographic complexity (rugosity). Spatially dense EAARL laser submarine topographic soundings acquired in August 2002 were used to create a 1-m resolution digital rugosity map for adjacent NFRT study areas characterized by patch reefs (Region A) and diverse substratums (Region B). In both regions, sites with lidar-sensed rugosities above 1.2 were imaged by an along-track underwater videography system that incorporated the acquisition of instantaneous GPS positions. Subsequent manual interpretation of videotape segments was performed to identify substratum types that caused elevated lidar-sensed rugosity. Our study determined that massive coral colony formation, modified by subsequent physical and biological processes that breakdown patch reef framework, was the primary source of topographic complexity sensed by the EAARL in the NFRT. Sites recognized by lidar scanning to be topographically complex preferentially occurred around the margins of patch reefs, constituted a minor fraction of the reef system, and usually reflected the presence of massive coral colonies in cluster zones, or their derivatives created by mortality, bioerosion, and physical breakdown.

Ecological intereactions of reef building corals

EPA Science Inventory

Coral reefs are very important marine ecosystems because they support tremendous biodiversity and reefs are critical economic resources many coastal nations. Tropical reef structures are largely built by stony corals. This presentation provides background on basic coral biology t...

Yolk formation in a stony coral Euphyllia ancora (Cnidaria, Anthozoa): insight into the evolution of vitellogenesis in nonbilaterian animals.

PubMed

Shikina, Shinya; Chen, Chieh-Jhen; Chung, Yi-Jou; Shao, Zi-Fan; Liou, Jhe-Yu; Tseng, Hua-Pin; Lee, Yan-Horn; Chang, Ching-Fong

2013-09-01

Vitellogenin (Vg) is a major yolk protein precursor in numerous oviparous animals. Numerous studies in bilateral oviparous animals have shown that Vg sequences are conserved across taxa and that Vgs are synthesized by somatic-cell lineages, transported to and accumulated in oocytes, and eventually used for supporting embryogenesis. In nonbilateral animals (Polifera, Cnidaria, and Ctenophora), which are regarded as evolutionarily primitive, although Vg cDNA has been identified in 2 coral species from Cnidaria, relatively little is known about the characteristics of yolk formation in their bodies. To address this issue, we identified and characterized 2 cDNA encoding yolk proteins, Vg and egg protein (Ep), in the stony coral Euphyllia ancora. RT-PCR analysis revealed that expression levels of both Vg and Ep increased in the female colonies as coral approached the spawning season. In addition, high levels of both Vg and Ep transcripts were detected in the putative ovarian tissue, as determined by tissue distribution analysis. Further analyses using mRNA in situ hybridization and immunohistochemistry determined that, within the putative ovarian tissue, these yolk proteins are synthesized in the mesenterial somatic cells but not in oocytes themselves. Furthermore, Vg proteins that accumulated in eggs were most likely consumed during the coral embryonic development, as assessed by immunoblotting. The characteristics of Vg that we identified in corals were somewhat similar to those of Vg in bilaterian oviparous animals, raising the hypothesis that such characteristics were likely present in the oogenesis of some common ancestor prior to divergence of the cnidarian and bilaterian lineages.

The Mediterranean stony coral Cladocora caespitosa (Linnaeus, 1767) as habitat provider for molluscs: colony size effect

NASA Astrophysics Data System (ADS)

Pitacco, Valentina; Crocetta, Fabio; Orlando-Bonaca, Martina; Mavrič, Borut; Lipej, Lovrenc

2017-11-01

The stony coral Cladocora caespitosa (Linnaeus, 1767) is an important Mediterranean habitat builder, whose survival is now being threatened by human activities and possibly natural events such as mass mortality and bleaching. We characterized the mollusc assemblage associated with colonies in the Gulf of Trieste (northern Adriatic Sea) and then tested whether the number of mollusc species increases in relation with colony size, following a Species-Area Relationship (SAR) model. At least 62 taxa were found in association with coral colonies, with bivalves constituting the dominant group. More than half of the 3034 specimens encountered were juveniles. Mollusc taxa richness increased with increasing C. caespitosa colony size according to the power-function model, whilst the analyses of trophic and functional groups supports the hypothesis of at least two factors underlying SAR (area per se and habitat diversity). Our results confirmed the importance of C. caespitosa for benthic communities, indicating that larger colonies support higher biodiversity, and suggesting that C. caespitosa is the most important habit builder among Mediterranean cnidarians, having also an influential function as a natural nursery ground. These results underline the necessity of new investigations aimed at filling gaps in our knowledge and planning new measures to protect the species.

Responses of reef building corals to microplastic exposure.

PubMed

Reichert, Jessica; Schellenberg, Johannes; Schubert, Patrick; Wilke, Thomas

2018-06-01

Pollution of marine environments with microplastic particles (i.e. plastic fragments <5 mm) has increased rapidly during the last decades. As these particles are mainly of terrestrial origin, coastal ecosystems such as coral reefs are particularly threatened. Recent studies revealed that microplastic ingestion can have adverse effects on marine invertebrates. However, little is known about its effects on small-polyp stony corals that are the main framework builders in coral reefs. The goal of this study is to characterise how different coral species I) respond to microplastic particles and whether the exposure might II) lead to health effects. Therefore, six small-polyp stony coral species belonging to the genera Acropora, Pocillopora, and Porites were exposed to microplastics (polyethylene, size 37-163 μm, concentration ca. 4000 particles L -1 ) over four weeks, and responses and effects on health were documented. The study showed that the corals responded differentially to microplastics. Cleaning mechanisms (direct interaction, mucus production) but also feeding interactions (i.e. interaction with mesenterial filaments, ingestion, and egestion) were observed. Additionally, passive contact through overgrowth was documented. In five of the six studied species, negative effects on health (i.e. bleaching and tissue necrosis) were reported. We here provide preliminary knowledge about coral-microplastic-interactions. The results call for further investigations of the effects of realistic microplastic concentrations on growth, reproduction, and survival of stony corals. This might lead to a better understanding of resilience capacities in coral reef ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Key Ecological Interactions of Reef Building Corals - 11-16-2011

EPA Science Inventory

Coral reefs are very important marine ecosystems because they support tremendous biodiversity and reefs are critical economic resources many coastal nations. Tropical reef structures are largely built by stony corals. This presentation provides background on basic coral biology t...

CHARACTERIZING CORAL CONDITION USING ESTIMATES OF THREE-DIMENSIONAL COLONY SURFACE AREA

EPA Science Inventory

Coral reefs provide shoreline protection, biological diversity, fishery harvets, and tourism, all values that stem from the physically-complex coral infrastructure. Stony corals (scleractinianss) construct and maintain the reef through deposition of calcium carbonate. Therefore...

Suppression of NF-κB signal pathway by NLRC3-like protein in stony coral Acropora aculeus under heat stress.

PubMed

Zhou, Zhi; Wu, Yibo; Zhang, Chengkai; Li, Can; Chen, Guangmei; Yu, Xiaopeng; Shi, Xiaowei; Xu, Yanlai; Wang, Lingui; Huang, Bo

2017-08-01

Heat stress is the most common factor for coral bleaching, which has increased both in frequency and severity due to global warming. In the present study, the stony coral Acropora aculeus was subjected to acute heat stress and entire transcriptomes were sequenced via the next generation sequencing platform. Four paired-end libraries were constructed and sequenced in two groups, including a control and a heat stress group. A total of 120,319,751 paired-end reads with lengths of 2 × 100 bp were assembled and 55,021 coral-derived genes were obtained. After read mapping and abundance estimation, 9110 differentially expressed genes were obtained in the comparison between the control and heat stress group, including 4465 significantly upregulated and 4645 significantly downregulated genes. Twenty-three GO terms in the Biological Process category were overrepresented for significantly upregulated genes, and divided into six groups according to their relationship. These three groups were related to the NF-κB signal pathway, and the remaining three groups were relevant for pathogen response, immunocyte activation and protein ubiquitination. Forty-three common genes were found in four GO terms, which were directly related to the NF-κB signal pathway. These included 2 NACHT, LRR, PYD domains-containing protein, 5 nucleotide-binding oligomerization domain-containing protein, 29 NLRC3-like protein, 4 NLRC5-like protein, and 3 uncharacterized protein. For significantly downregulated genes, 27 overrepresented GO terms were found in the Biological Process category, which were relevant to protein ubiquitination and ATP metabolism. Our results indicate that heat stress suppressed the immune response level via the NLRC3-like protein, the fine-tuning of protein turnover activity, and ATP metabolism. This might disrupt the balance of coral-zooxanthellae symbiosis and result in the bleaching of the coral A. aculeus. Copyright © 2017 Elsevier Ltd. All rights reserved.

GENETIC INDICATORS OF ENVIRONMENTAL STRESS IN HERMATYPIC CORALS

EPA Science Inventory

An efficient, low cost method was developed for the detection of rapid changes in coral gene expression at the messenger ribonucleic acid (mRNA) level. Hermatypic (stony) corals were exposed to a variety of organic and inorganic toxicants and physical stressors at several concent...

ROLE OF CORAL DISEASES AND ANTHROPOGENIC STRESSORS ON TROPIC MARINE CORAL REEFS

EPA Science Inventory

Stony (scleractinian) and soft (octocorals) corals throughout the Western Atlantic have been affected by several fatal diseases in the last two decades. In many locations the communities have not recovered from these diseases and the ecosystem has permanently changed. Several hyp...

Estimating 3-dimensional colony surface area of field corals

EPA Science Inventory

Colony surface area is a critical descriptor for biological and physical attributes of reef-building (scleractinian, stony) corals. The three-dimensional (3D) size and structure of corals are directly related to many ecosystem values and functions. Most methods to estimate colony...

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

EPA Pesticide Factsheets

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

Depth and coral cover drive the distribution of a coral macroborer across two reef systems.

PubMed

Maher, Rebecca L; Johnston, Michelle A; Brandt, Marilyn E; Smith, Tyler B; Correa, Adrienne M S

2018-01-01

Bioerosion, the removal of calcium carbonate from coral frameworks by living organisms, influences a variety of reef features, from their topographic complexity to the net balance of carbonate budgets. Little is known, however, about how macroborers, which bore into reef substrates leaving traces greater than 0.1 mm diameter, are distributed across coral reefs, particularly reef systems with high (>50%) stony coral cover or at mesophotic depths (≥30 m). Here, we present an accurate and efficient method for quantifying macroborer densities from stony coral hosts via image analysis, using the bioeroding barnacle, Lithotrya dorsalis, and its host coral, Orbicella franksi, as a case study. We found that in 2014, L. dorsalis densities varied consistently with depth and host percent cover in two Atlantic reef systems: the Flower Garden Banks (FGB, northwest Gulf of Mexico) and the U.S. Virgin Islands (USVI). Although average barnacle density was nearly 4.5 times greater overall in the FGB than in the USVI, barnacle density decreased with depth in both reef regions. Barnacle density also scaled negatively with increasing coral cover in the study areas, suggesting that barnacle populations are not strictly space-limited in their distribution and settlement opportunities. Our findings suggest that depth and host coral cover, and potentially, local factors may strongly influence the abundance of macroborers, and thus the rate of CaCO3 loss, in a given reef system. Our image analysis method for quantifying macroborers can be standardized across historical and modern reef records to better understand how borers impact host growth and reef health.

Benthic community structure on coral reefs exposed to intensive recreational snorkeling.

PubMed

Renfro, Bobbie; Chadwick, Nanette E

2017-01-01

Chronic anthropogenic disturbances on coral reefs in the form of overfishing and pollution can shift benthic community composition away from stony corals and toward macroalgae. The use of reefs for recreational snorkeling and diving potentially can lead to similar ecological impacts if not well-managed, but impacts of snorkeling on benthic organisms are not well understood. We quantified variation in benthic community structure along a gradient of snorkeling frequency in an intensively-visited portion of the Mesoamerican Barrier Reef. We determined rates of snorkeling in 6 water sections and rates of beach visitation in 4 adjacent land sections at Akumal Bay, Mexico. For each in-water section at 1-3 m depth, we also assessed the percent cover of benthic organisms including taxa of stony corals and macroalgae. Rates of recreational snorkeling varied from low in the southwestern to very high (>1000 snorkelers d-1) in the northeastern sections of the bay. Stony coral cover decreased and macroalgal cover increased significantly with levels of snorkeling, while trends varied among taxa for other organisms such as gorgonians, fire corals, and sea urchins. We conclude that benthic organisms appear to exhibit taxon-specific variation with levels of recreational snorkeling. To prevent further degradation, we recommend limitation of snorkeler visitation rates, coupled with visitor education and in-water guides to reduce reef-damaging behaviors by snorkelers in high-use areas. These types of management activities, integrated with reef monitoring and subsequent readjustment of management, have the potential to reverse the damage potentially inflicted on coral reefs by the expansion of reef-based recreational snorkeling.

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

EPA Science Inventory

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

Coral Reef Biological Criteria: Using Clean Water Act to Protect a National Treasure

EPA Science Inventory

A collaborative Environmental Protection Agency effort is underway to elucidate the technical aspects of coral reef biocriteria implementation. A stony coral rapid bioassessment protocol has been introduced and applied in the Florida Keys and U.S. Virgin Islands, where several in...

Benthic community structure on coral reefs exposed to intensive recreational snorkeling

PubMed Central

Renfro, Bobbie

2017-01-01

Chronic anthropogenic disturbances on coral reefs in the form of overfishing and pollution can shift benthic community composition away from stony corals and toward macroalgae. The use of reefs for recreational snorkeling and diving potentially can lead to similar ecological impacts if not well-managed, but impacts of snorkeling on benthic organisms are not well understood. We quantified variation in benthic community structure along a gradient of snorkeling frequency in an intensively-visited portion of the Mesoamerican Barrier Reef. We determined rates of snorkeling in 6 water sections and rates of beach visitation in 4 adjacent land sections at Akumal Bay, Mexico. For each in-water section at 1–3 m depth, we also assessed the percent cover of benthic organisms including taxa of stony corals and macroalgae. Rates of recreational snorkeling varied from low in the southwestern to very high (>1000 snorkelers d-1) in the northeastern sections of the bay. Stony coral cover decreased and macroalgal cover increased significantly with levels of snorkeling, while trends varied among taxa for other organisms such as gorgonians, fire corals, and sea urchins. We conclude that benthic organisms appear to exhibit taxon-specific variation with levels of recreational snorkeling. To prevent further degradation, we recommend limitation of snorkeler visitation rates, coupled with visitor education and in-water guides to reduce reef-damaging behaviors by snorkelers in high-use areas. These types of management activities, integrated with reef monitoring and subsequent readjustment of management, have the potential to reverse the damage potentially inflicted on coral reefs by the expansion of reef-based recreational snorkeling. PMID:28873449

Proteomic analysis of skeletal organic matrix from the stony coral Stylophora pistillata

PubMed Central

Drake, Jeana L.; Mass, Tali; Haramaty, Liti; Zelzion, Ehud; Bhattacharya, Debashish; Falkowski, Paul G.

2013-01-01

It has long been recognized that a suite of proteins exists in coral skeletons that is critical for the oriented precipitation of calcium carbonate crystals, yet these proteins remain poorly characterized. Using liquid chromatography-tandem mass spectrometry analysis of proteins extracted from the cell-free skeleton of the hermatypic coral, Stylophora pistillata, combined with a draft genome assembly from the cnidarian host cells of the same species, we identified 36 coral skeletal organic matrix proteins. The proteome of the coral skeleton contains an assemblage of adhesion and structural proteins as well as two highly acidic proteins that may constitute a unique coral skeletal organic matrix protein subfamily. We compared the 36 skeletal organic matrix protein sequences to genome and transcriptome data from three other corals, three additional invertebrates, one vertebrate, and three single-celled organisms. This work represents a unique extensive proteomic analysis of biomineralization-related proteins in corals from which we identify a biomineralization “toolkit,” an organic scaffold upon which aragonite crystals can be deposited in specific orientations to form a phenotypically identifiable structure. PMID:23431140

Transcriptome of the Caribbean stony coral Porites astreoides from three developmental stages.

PubMed

Mansour, Tamer A; Rosenthal, Joshua J C; Brown, C Titus; Roberson, Loretta M

2016-08-02

Porites astreoides is a ubiquitous species of coral on modern Caribbean reefs that is resistant to increasing temperatures, overfishing, and other anthropogenic impacts that have threatened most other coral species. We assembled and annotated a transcriptome from this coral using Illumina sequences from three different developmental stages collected over several years: free-swimming larvae, newly settled larvae, and adults (>10 cm in diameter). This resource will aid understanding of coral calcification, larval settlement, and host-symbiont interactions. A de novo transcriptome for the P. astreoides holobiont (coral plus algal symbiont) was assembled using 594 Mbp of raw Illumina sequencing data generated from five age-specific cDNA libraries. The new transcriptome consists of 867 255 transcript elements with an average length of 685 bases. The isolated P. astreoides assembly consists of 129 718 transcript elements with an average length of 811 bases, and the isolated Symbiodinium sp. assembly had 186 177 transcript elements with an average length of 1105 bases. This contribution to coral transcriptome data provides a valuable resource for researchers studying the ontogeny of gene expression patterns within both the coral and its dinoflagellate symbiont.

Assessing land use, sedimentation, and water quality stressors as predictors of coral reef condition in St. Thomas, U.S. Virgin Islands.

PubMed

Oliver, L M; Fisher, W S; Fore, L; Smith, A; Bradley, P

2018-03-13

Coral reef condition on the south shore of St. Thomas, U.S. Virgin Islands, was assessed at various distances from Charlotte Amalie, the most densely populated city on the island. Human influence in the area includes industrial activity, wastewater discharge, cruise ship docks, and impervious surfaces throughout the watershed. Anthropogenic activity was characterized using a landscape development intensity (LDI) index, sedimentation threat (ST) estimates, and water quality (WQ) impairments in the near-coastal zone. Total three-dimensional coral cover, reef rugosity, and coral diversity had significant negative coefficients for LDI index, as did densities of dominant species Orbicella annularis, Orbicella franksi, Montastraea cavernosa, Orbicella faveolata, and Porites porites. However, overall stony coral colony density was not significantly correlated with stressors. Positive relationships between reef rugosity and ST, between coral diversity and ST, and between coral diversity and WQ were unexpected because these stressors are generally thought to negatively influence coral growth and health. Sponge density was greater with higher disturbance indicators (ST and WQ), consistent with reports of greater resistance by sponges to degraded water quality compared to stony corals. The highest FoRAM (Foraminifera in Reef Assessment and Monitoring) indices indicating good water quality were found offshore from the main island and outside the harbor. Negative associations between stony coral metrics and LDI index have been reported elsewhere in the Caribbean and highlight LDI index potential as a spatial tool to characterize land-based anthropogenic stressor gradients relevant to coral reefs. Fewer relationships were found with an integrated stressor index but with similar trends in response direction.

Eukarya associated with the stony coral Oculina patagonica from the Mediterranean Sea.

PubMed

Rubio-Portillo, Esther; Souza-Egipsy, Virginia; Ascaso, Carmen; de Los Rios Murillo, Asunción; Ramos-Esplá, Alfonso A; Antón, Josefa

2014-10-01

Oculina patagonica is a putative alien scleractinian coral from the Southwest Atlantic that inhabits across the Mediterranean Sea. Here, we have addressed the diversity of Eukarya associated with this coral and its changes related to the environmental conditions and coral status. A total of 46 colonies of O. patagonica were taken from Alicante coast (Spain) and Pietra Ligure coast (Italy) and analyzed using denaturing gradient gel electrophoresis (DGGE) of the small-subunit 18S rRNA and 16S plastid rRNA genes, internal transcribed spacer region 2 (ITS 2) analyses, and electron microscopy. Our results show that Eukarya and plastid community associated to O. patagonica change with environmental conditions and coral status. Cryptic species, which can be difficult to identify by optical methods, were distinguished by 18S rRNA gene DGGE: the barnacle Megatrema anglicum, which was detected at two locations, and two boring sponges related to Cliona sp. and Siphonodictyon coralliphagum detected in samples from Tabarca and Alicante Harbour, respectively. Eukaryotic phototrophic community from the skeletal matrix of healthy corals was dominated by Ochrosphaera sp. while bleached corals from the Harbour and Tabarca were associated to different uncultured phototrophic organism. Differences in ultrastructural morphologies of the zooxanthellae between healthy and bleached corals were observed. Nevertheless, no differences were found in Symbiodinium community among time, environments, coral status and location, showing that O. patagonica hosted only one genotype of Symbiodinium belonging to clade B2. The fact that this clade has not been previously detected in other Mediterranean corals and is more frequent in the tropical Western Atlantic, is a new evidence that O. patagonica is an alien species in the Mediterranean Sea. Copyright © 2014 Elsevier B.V. All rights reserved.

How does the proliferation of the coral-killing sponge Terpios hoshinota affect benthic community structure on coral reefs?

NASA Astrophysics Data System (ADS)

Elliott, Jennifer; Patterson, Mark; Summers, Natalie; Miternique, Céline; Montocchio, Emma; Vitry, Eugene

2016-09-01

Terpios hoshinota is an encrusting sponge and a fierce space competitor. It kills stony corals by overgrowing them and can impact reefs on the square kilometer scale. We investigated an outbreak of T. hoshinota in 2014 at the island of Mauritius to determine its impacts on coral community structure. Surveys were conducted at the putative outbreak center, an adjacent area, and around the island to determine the extent of spread of the sponge and which organisms it impacted. In addition, quadrats were monitored for 5 months (July-December) to measure the spreading rates of T. hoshinota and Acropora austera in areas both with and without T. hoshinota. The photosynthetic capabilities of T. hoshinota and A. austera were also measured. Terpios hoshinota was well established, covering 13% of an estimated 416 m2 of available hard coral substrate at the putative outbreak center, and 10% of an estimated 588 m2 of available hard coral substrate at the adjacent area. The sponge was observed at only one other site around Mauritius. Terpios hoshinota and A. austera increased their planar areas by 26.9 and 13.9%, respectively, over five months. No new colonies of T. hoshinota were recorded in adjacent sponge-free control areas, suggesting that sponge recruitment is very low during austral winter and spring. The sponge was observed to overgrow five stony corals; however, it showed a preference for branching corals, especially A. austera. This is the first time that a statistically significant coral substrate preference by T. hoshinota has been reported. Terpios hoshinota also had a significantly higher photosynthetic capacity than A. austera at irradiance >500 μmol photons m-2 s-1, a possible explanation for its high spreading rate. We discuss the long-term implications of the proliferation of T. hoshinota on community structure and dynamics of our study site.

Molecular cloning and characterization of a steroidogenic enzyme, 17β-hydroxysteroid dehydrogenase type 14, from the stony coral Euphyllia ancora (Cnidaria, Anthozoa).

PubMed

Shikina, Shinya; Chung, Yi-Jou; Chiu, Yi-Ling; Huang, Yi-Jie; Lee, Yan-Horn; Chang, Ching-Fong

2016-03-01

Sex steroids play a fundamental role not only in reproduction but also in various other biological processes in vertebrates. Although the presence of sex steroids has been confirmed in cnidarians (e.g., coral, sea anemone, jellyfish, and hydra), which are basal metazoans, only a few studies to date have characterized steroidogenesis-related genes in cnidarians. Based on a transcriptomic analysis of the stony coral Euphyllia ancora, we identified the steroidogenic enzyme 17β-hydroxysteroid dehydrogenase type 14 (17beta-hsd 14), an oxidative enzyme that catalyzes the NAD(+)-dependent inactivation of estrogen/androgen (estradiol to estrone and testosterone to androstenedione) in mammals. Phylogenetic analysis showed that E. ancora 17beta-Hsd 14 (Ea17beta-Hsd 14) clusters with other animal 17beta-HSD 14s but not with other members of the 17beta-HSD family. Subsequent quantitative RT-PCR analysis revealed a lack of correlation of Ea17beta-hsd 14 transcript levels with the coral's reproductive cycle. In addition, Ea17beta-hsd 14 transcript and protein were detected in all tissues examined, such as the tentacles, mesenterial filaments, and gonads, at similar levels in both sexes, as determined by quantitative RT-PCR analysis and Western blotting with an anti-Ea17beta-Hsd 14 antibody. Immunohistochemical analysis revealed that Ea17beta-Hsd 14 is mainly distributed in the endodermal regions of the polyps, but the protein was also observed in all tissues examined. These results suggest that Ea17beta-Hsd 14 is involved in important functions that commonly occur in endodermal cells or has multiple functions in different tissues. Our data provide information for comparison with advanced animals as well as insight into the evolution of steroidogenesis-related genes in metazoans. Copyright © 2016 Elsevier Inc. All rights reserved.

Water movement in stony soils: The influence of stoniness on soil water content profiles

NASA Astrophysics Data System (ADS)

Novak, Viliam; Knava, Karol

2010-05-01

WATER MOVEMENT IN STONY SOILS: THE INFLUENCE OF STONINESS ON SOIL WATER CONTENT PROFILES Viliam Novák, Karol Kňava Institute of Hydrology, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3, Slovakia, e-mail: novak@uh.savba.sk Soils containing rock fragments are widespread over the world, on Europe such soil account for 30%, 60% in Mediterranean region. In comparison to fine earth soils (soil particles are less then 2 mm) stony soils contain rock fragments characterized by the low retention capacity and hydraulic conductivity. So, for stony soils -in comparison to the fine-earth soils - is typical lower hydraulic conductivity and retention capacity, which lead to the decrease decrease of infiltration rate and low water retention. So, water movement and its modeling in stony soil would differ from fine earth (usually agricultural) soil. The aim of this contribution is to demonstrate the differences in water movement in homogeneous soil (fine earth) and stony soil. The influence of different stoniness on soil water content and soil water dynamics was studied too. Windthrow at High Tatra mountains in Slovakia (November 2004) cleared nearly 12 000 ha of 80 year conifers and this event initiated complex research of windthrow impact on the ecosystem. The important part of this study was water movement in impacted area. Specific feature of the soil in this area was moraine soil consisting of fine earth, characterized as silty sand, with the relative stone content up to 0.49, increasing with depth. Associated phenomenon to the forest clearing is the decrease of rain interception and higher undercanopy precipitation. Conifers interception capacity can be three times higher than low canopy interception, and can reach up to 40% of annual precipitation in Central Europe. Stones in the soil are decreasing infiltration rate, but paradoxically increased understorey precipitation and followingly the increased cumulative infiltration led to the increase of the soil

Turbulence, cleavage, and the naked embryo: a case for coral clones.

PubMed

Heyward, A J; Negri, A P

2012-03-02

After mass spawning events, coral embryos, lacking the protective capsule of other metazoans, are directly exposed to the environment at the ocean surface. Here, we present evidence that modest turbulence disrupts the integrity of these embryos, which fragment into totipotent cells that develop into proportionately smaller functional larvae. The level of turbulence required to fragment coral embryos can be generated from small wind-generated waves, which occur frequently during coral spawning on the Great Barrier Reef. The formation of planktonic coral clones, through natural embryo fragmentation of broadcast spawn, is a previously unknown mode of reproduction in the animal kingdom.

The “Naked Coral” Hypothesis Revisited – Evidence for and Against Scleractinian Monophyly

PubMed Central

Forêt, Sylvain; Huttley, Gavin; Miller, David J.; Chen, Chaolun Allen

2014-01-01

The relationship between Scleractinia and Corallimorpharia, Orders within Anthozoa distinguished by the presence of an aragonite skeleton in the former, is controversial. Although classically considered distinct groups, some phylogenetic analyses have placed the Corallimorpharia within a larger Scleractinia/Corallimorpharia clade, leading to the suggestion that the Corallimorpharia are “naked corals” that arose via skeleton loss during the Cretaceous from a Scleractinian ancestor. Scleractinian paraphyly is, however, contradicted by a number of recent phylogenetic studies based on mt nucleotide (nt) sequence data. Whereas the “naked coral” hypothesis was based on analysis of the sequences of proteins encoded by a relatively small number of mt genomes, here a much-expanded dataset was used to reinvestigate hexacorallian phylogeny. The initial observation was that, whereas analyses based on nt data support scleractinian monophyly, those based on amino acid (aa) data support the “naked coral” hypothesis, irrespective of the method and with very strong support. To better understand the bases of these contrasting results, the effects of systematic errors were examined. Compared to other hexacorallians, the mt genomes of “Robust” corals have a higher (A+T) content, codon usage is far more constrained, and the proteins that they encode have a markedly higher phenylalanine content, leading us to suggest that mt DNA repair may be impaired in this lineage. Thus the “naked coral” topology could be caused by high levels of saturation in these mitochondrial sequences, long-branch effects or model violations. The equivocal results of these extensive analyses highlight the fundamental problems of basing coral phylogeny on mitochondrial sequence data. PMID:24740380

Bacterial populations and adaptations in the mucus layers on living corals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ducklow, H.W.; Mitchell, R.

1979-07-01

The external mucus layers of the stony coral Porites astreoides and the soft corals Palythoa sp. and Heteroxenia fuscesens are inhabited by communities of marine heterotrophic bacteria. Population levels of bacteria in coral mucus may be regulated by the self-cleaning behavior of the host. Bacterial populations in coral mucus respond to stresses applied to the host coral by growing to higher population levels in the mucus, indicating that these are populations of viable organisms closely attuned to host metabolism. Members of these microbial populations utilize the mucus compounds and may play a role in processing coral mucus for reef detritusmore » feeders. One such species, Vibrio alginolyticus, grows rapidly on Heteroxenia mucus, is attracted to dissolved mucus, and possesses a mechanism to maintain itself on the coral surface.« less

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.

A Trait-Based Approach to Advance Coral Reef Science.

PubMed

Madin, Joshua S; Hoogenboom, Mia O; Connolly, Sean R; Darling, Emily S; Falster, Daniel S; Huang, Danwei; Keith, Sally A; Mizerek, Toni; Pandolfi, John M; Putnam, Hollie M; Baird, Andrew H

2016-06-01

Coral reefs are biologically diverse and ecologically complex ecosystems constructed by stony corals. Despite decades of research, basic coral population biology and community ecology questions remain. Quantifying trait variation among species can help resolve these questions, but progress has been hampered by a paucity of trait data for the many, often rare, species and by a reliance on nonquantitative approaches. Therefore, we propose filling data gaps by prioritizing traits that are easy to measure, estimating key traits for species with missing data, and identifying 'supertraits' that capture a large amount of variation for a range of biological and ecological processes. Such an approach can accelerate our understanding of coral ecology and our ability to protect critically threatened global ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genome-Based Analyses of Six Hexacorallian Species Reject the "Naked Coral" Hypothesis.

PubMed

Wang, Xin; Drillon, Guénola; Ryu, Taewoo; Voolstra, Christian R; Aranda, Manuel

2017-10-01

Scleractinian corals are the foundation species of the coral-reef ecosystem. Their calcium carbonate skeletons form extensive structures that are home to millions of species, making coral reefs one of the most diverse ecosystems of our planet. However, our understanding of how reef-building corals have evolved the ability to calcify and become the ecosystem builders they are today is hampered by uncertain relationships within their subclass Hexacorallia. Corallimorpharians have been proposed to originate from a complex scleractinian ancestor that lost the ability to calcify in response to increasing ocean acidification, suggesting the possibility for corals to lose and gain the ability to calcify in response to increasing ocean acidification. Here, we employed a phylogenomic approach using whole-genome data from six hexacorallian species to resolve the evolutionary relationship between reef-building corals and their noncalcifying relatives. Phylogenetic analysis based on 1,421 single-copy orthologs, as well as gene presence/absence and synteny information, converged on the same topologies, showing strong support for scleractinian monophyly and a corallimorpharian sister clade. Our broad phylogenomic approach using sequence-based and sequence-independent analyses provides unambiguous evidence for the monophyly of scleractinian corals and the rejection of corallimorpharians as descendants of a complex coral ancestor. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

BIOACCUMULATION AND HISTOPATHOLOGICAL EFFECTS OF OIL ON A STONY CORAL

EPA Science Inventory

Colonies of the shallow-water Caribbean coral Manicina areolata incorporated petroleum hydrocarbons into their tissues during exposure to water accommodated fractions of No. 2 fuel oil for three months. This contamination was not removed after depuration periods of up to two week...

Virus-host interactions and their roles in coral reef health and disease.

PubMed

Thurber, Rebecca Vega; Payet, Jérôme P; Thurber, Andrew R; Correa, Adrienne M S

2017-04-01

Coral reefs occur in nutrient-poor shallow waters, constitute biodiversity and productivity hotspots, and are threatened by anthropogenic disturbance. This Review provides an introduction to coral reef virology and emphasizes the links between viruses, coral mortality and reef ecosystem decline. We describe the distinctive benthic-associated and water-column- associated viromes that are unique to coral reefs, which have received less attention than viruses in open-ocean systems. We hypothesize that viruses of bacteria and eukaryotes dynamically interact with their hosts in the water column and with scleractinian (stony) corals to influence microbial community dynamics, coral bleaching and disease, and reef biogeochemical cycling. Last, we outline how marine viruses are an integral part of the reef system and suggest that the influence of viruses on reef function is an essential component of these globally important environments.

Key functional role of the optical properties of coral skeletons in coral ecology and evolution.

PubMed

Enríquez, Susana; Méndez, Eugenio R; Hoegh-Guldberg, Ove; Iglesias-Prieto, Roberto

2017-04-26

Multiple scattering of light on coral skeleton enhances light absorption efficiency of coral symbionts and plays a key role in the regulation of their internal diffuse light field. To understand the dependence of this enhancement on skeleton meso- and macrostructure, we analysed the scattering abilities of naked coral skeletons for 74 Indo-Pacific species. Sensitive morphotypes to thermal and light stress, flat-extraplanate and branching corals, showed the most efficient structures, while massive-robust species were less efficient. The lowest light-enhancing scattering abilities were found for the most primitive colonial growth form: phaceloid. Accordingly, the development of highly efficient light-collecting structures versus the selection of less efficient but more robust holobionts to cope with light stress may constitute a trade-off in the evolution of modern symbiotic scleractinian corals, characterizing two successful adaptive solutions. The coincidence of the most important structural modifications with epitheca decline supports the importance of the enhancement of light transmission across coral skeleton in modern scleractinian diversification, and the central role of these symbioses in the design and optimization of coral skeleton. Furthermore, the same ability that lies at the heart of the success of symbiotic corals as coral-reef-builders can also explain the 'Achilles's heel' of these symbioses in a warming ocean. © 2017 The Author(s).

Long-distance transport of a West Atlantic stony coral on a plastic raft.

PubMed

Hoeksema, Bert W; Pedoja, Kevin; Poprawski, Yohann

2018-05-30

The occurrence of wide-spread coral species around isolated reefs and over long stretches of deep ocean cannot be explained by larval dispersal alone; their larval stage is too short for that, especially in brooding species (Nunes et al. 2011, de Souza et al. 2017). Rafting on natural substrates, such as volcanic pumice fragments, wooden logs and coconut shells has been recognized as an alternative means for transport in reef corals (Fielden 1893, Crossland 1952, Jokiel 1984). Fouling on ship hulls and oil platforms is a relatively new, anthropogenic way for coral migration and because it is fast, it escalates the risk of alien species introductions (Creed et al. 2017). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Dongsha Atoll: A potential thermal refuge for reef-building corals in the South China Sea.

PubMed

Tkachenko, Konstantin S; Soong, Keryea

2017-06-01

Dongsha Atoll (also known as the Pratas Islands), the northernmost atoll in the South China Sea, experiences two contrasting physical phenomena: repetitive anomalies of the sea surface temperature exceeding the coral bleaching threshold and regular effects of the world's strongest internal waves resulting in the rhythmic upwelling of cold deep waters at the outer reef slopes of the atoll. This unique combination may result in significant differences in coral species composition and structure between the lagoon and forereef. Surveys conducted in August-September 2016 at 12 study sites in the 2-15 m depth range at Dongsha Atoll revealed a clear spatial separation between 'thermally-susceptible' stony coral genera, including Acropora, Pocillopora and Montipora, which mainly inhabited the forereef, and 'thermally-resistant' genera, including massive Porites, foliaceous Echinopora, Pavona and Turbinaria, which mainly resided in the lagoon. The mean coral cover and species richness on the forereef were respectively 1.8 and 1.4 times higher than those in the lagoon (61.3% and 98 species on the forereef vs. 34.2% and 69 species in the lagoon). Coral mortality rates, expressed as the ratio of dead to live stony corals, showed the same pattern (0.4 in the lagoon vs. 0.009 on the forereef). Furthermore, in a laboratory experiment, 'thermally-susceptible' taxa from the lagoon, (e.g. Pocillopora verrucosa and P. damicornis), exhibited higher resistance to bleaching than did their counterparts from the forereef. The present findings indicate that Dongsha Atoll is a potential thermal refuge for reef-building corals in the northern South China Sea and reveal the development of resilience and resistance to bleaching in coral communities of the lagoon. Copyright © 2017 Elsevier Ltd. All rights reserved.

The digestive system of the stony coral Stylophora pistillata.

PubMed

Raz-Bahat, M; Douek, J; Moiseeva, E; Peters, E C; Rinkevich, B

2017-05-01

Because hermatypic species use symbiotic algal photosynthesis, most of the literature in this field focuses on this autotrophic mode and very little research has studied the morphology of the coral's digestive system or the digestion process of particulate food. Using histology and histochemestry, our research reveals that Stylophora pistillata's digestive system is concentrated at the corals' peristome, actinopharynx and mesenterial filaments (MF). We used in-situ hybridization (ISH) of the RNA transcript of the gene that codes for the S. pistillata digestive enzyme, chymotrypsinogen, to shed light on the functionality of the digestive system. Both the histochemistry and the ISH pointed to the MF being specialized digestive organs, equipped with large numbers of acidophilic and basophilic granular gland cells, as well as acidophilic non-granular gland cells, some of which produce chymotrypsinogen. We identified two types of MF: short, trilobed MF and unilobed, long and convoluted MF. Each S. pistillata polyp harbors two long convoluted MF and 10 short MF. While the short MF have neither secreting nor stinging cells, each of the convoluted MF display gradual cytological changes along their longitudinal axis, alternating between stinging and secreting cells and three distinctive types of secretory cells. These observations indicate the important digestive role of the long convoluted MF. They also indicate the existence of novel feeding compartments in the gastric cavity of the polyp, primarily in the nutritionally active peristome, in the actinopharynx and in three regions of the MF that differ from each other in their cellular components, general morphology and chymotrypsinogen excretion.

Comparative genomics explains the evolutionary success of reef-forming corals.

PubMed

Bhattacharya, Debashish; Agrawal, Shobhit; Aranda, Manuel; Baumgarten, Sebastian; Belcaid, Mahdi; Drake, Jeana L; Erwin, Douglas; Foret, Sylvian; Gates, Ruth D; Gruber, David F; Kamel, Bishoy; Lesser, Michael P; Levy, Oren; Liew, Yi Jin; MacManes, Matthew; Mass, Tali; Medina, Monica; Mehr, Shaadi; Meyer, Eli; Price, Dana C; Putnam, Hollie M; Qiu, Huan; Shinzato, Chuya; Shoguchi, Eiichi; Stokes, Alexander J; Tambutté, Sylvie; Tchernov, Dan; Voolstra, Christian R; Wagner, Nicole; Walker, Charles W; Weber, Andreas Pm; Weis, Virginia; Zelzion, Ehud; Zoccola, Didier; Falkowski, Paul G

2016-05-24

Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years.

Conservation genetics and the resilience of reef-building corals.

PubMed

van Oppen, Madeleine J H; Gates, Ruth D

2006-11-01

Coral reefs have suffered long-term decline due to a range of anthropogenic disturbances and are now also under threat from climate change. For appropriate management of these vulnerable and valuable ecosystems it is important to understand the factors and processes that determine their resilience and that of the organisms inhabiting them, as well as those that have led to existing patterns of coral reef biodiversity. The scleractinian (stony) corals deposit the structural framework that supports and promotes the maintenance of biological diversity and complexity of coral reefs, and as such, are major components of these ecosystems. The success of reef-building corals is related to their obligate symbiotic association with dinoflagellates of the genus Symbiodinium. These one-celled algal symbionts (zooxanthellae) live in the endodermal tissues of their coral host, provide most of the host's energy budget and promote rapid calcification. Furthermore, zooxanthellae are the main primary producers on coral reefs due to the oligotrophic nature of the surrounding waters. In this review paper, we summarize and critically evaluate studies that have employed genetics and/or molecular biology in examining questions relating to the evolution and ecology of reef-building corals and their algal endosymbionts, and that bear relevance to coral reef conservation. We discuss how these studies can focus future efforts, and examine how these approaches enhance our understanding of the resilience of reef-building corals.

Workshop on Biological Integrity of Coral Reefs August 21-22 ...

EPA Pesticide Factsheets

This report summarizes an EPA-sponsored workshop on coral reef biological integrity held at the Caribbean Coral Reef Institute in La Parguera, Puerto Rico on August 21-22, 2012. The goals of this workshop were to:• Identify key qualitative and quantitative ecological characteristics (reef attributes) that determine the condition of linear coral reefs inhabiting shallow waters (<12 m) in southwestern Puerto Rico.• Use those reef attributes to recommend categorical condition rankings for establishing a biological condition gradient.• Ascertain through expert consensus those reef attributes that characterize biological integrity (a natural, fully-functioning system of organisms and communities) for coral reefs. • Develop a conceptual, narrative model that describes how biological attributes of coral reefs change along a gradient of increasing anthropogenic stress.The workshop brought together scientists with expertise in coral reef taxonomic groups (e.g., stony corals, fishes, sponges, gorgonians, algae, seagrasses and macroinvertebrates), as well as community structure, organism condition, ecosystem function and ecosystem connectivity. The experts evaluated photos and videos from 12 stations collected during EPA Coral Reef surveys (2010 & 2011) from Puerto Rico on coral reefs exhibiting a wide range of conditions. The experts individually rated each station as to observed condition (“good”, “fair” or “poor”) and documented their rationale for

Comparative genomics explains the evolutionary success of reef-forming corals

PubMed Central

Bhattacharya, Debashish; Agrawal, Shobhit; Aranda, Manuel; Baumgarten, Sebastian; Belcaid, Mahdi; Drake, Jeana L; Erwin, Douglas; Foret, Sylvian; Gates, Ruth D; Gruber, David F; Kamel, Bishoy; Lesser, Michael P; Levy, Oren; Liew, Yi Jin; MacManes, Matthew; Mass, Tali; Medina, Monica; Mehr, Shaadi; Meyer, Eli; Price, Dana C; Putnam, Hollie M; Qiu, Huan; Shinzato, Chuya; Shoguchi, Eiichi; Stokes, Alexander J; Tambutté, Sylvie; Tchernov, Dan; Voolstra, Christian R; Wagner, Nicole; Walker, Charles W; Weber, Andreas PM; Weis, Virginia; Zelzion, Ehud; Zoccola, Didier; Falkowski, Paul G

2016-01-01

Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years. DOI: http://dx.doi.org/10.7554/eLife.13288.001 PMID:27218454

The soil water regime of stony soils in a mountain catchment

NASA Astrophysics Data System (ADS)

Hlaváčiková, Hana; Danko, Michal; Holko, Ladislav; Hlavčo, Jozef; Novák, Viliam

2016-04-01

Investigation of processes related to runoff generation is an important topic in catchment hydrology. Observations are usually carried out in small catchments or on hillslopes. Many of such catchments are located in mountain or forested areas. From many studies it is evident that soil conditions and soil characteristics are one of the crucial factors in runoff generation. Mountainous or forest soils have usually high rock fragments content. Nevertheless, the influence of soil stoniness on water flow was not sufficiently studied up to now at catchment and hillslope scales due to flow formation complexity or problems with stony soil properties measurement (installing measuring devices, interpretation of measured data). Results of this work can be divided in two groups: (1) hydrophysical properties of stony soils measurements, and (2) water flow dynamic modelling in stony soils. Properties of stony soils were measured in the Jalovecky creek catchment, the Western Tatra Mts., Slovakia. Altitude of particular study sites varies from 780 to1500 m a.s.l. We measured and analyzed the stoniness of reference soil profiles, as well as retention properties of stony soils (fine soil fraction and rock fragments separately) and hydraulic conductivities of surface and subsurface soil layers. The methodology for determination of the effective hydrophysical properties of a stony soil (later used in modelling) was proposed using results from measurements, calculation, and numerical Darcy experiments. Modelling results show that the presence of rock fragments with low water retention in a stony soil with moderate or high stoniness can cause the soil water storage decrease by 16-31% in compared to the soil without rock fragments. In addition, decreased stony soil retention capacity resulted in faster outflow increase at the bottom of the soil profile during non-ponding infiltration. Furthermore, the presence of rock fragments can increase maximum outflow value. It is not possible to

Benefit of pulsation in soft corals.

PubMed

Kremien, Maya; Shavit, Uri; Mass, Tali; Genin, Amatzia

2013-05-28

Soft corals of the family Xeniidae exhibit a unique, rhythmic pulsation of their tentacles (Movie S1), first noted by Lamarck nearly 200 y ago. However, the adaptive benefit of this perpetual, energetically costly motion is poorly understood. Using in situ underwater particle image velocimetry, we found that the pulsation motions thrust water upward and enhance mixing across the coral-water boundary layer. The induced upward motion effectively prevents refiltration of water by neighboring polyps, while the intensification of mixing, together with the upward flow, greatly enhances the coral's photosynthesis. A series of controlled laboratory experiments with the common xeniid coral Heteroxenia fuscescens showed that the net photosynthesis rate during pulsation was up to an order of magnitude higher than during the coral's resting, nonpulsating state. This enhancement diminished when the concentration of oxygen in the ambient water was artificially raised, indicating that the enhancement of photosynthesis was due to a greater efflux of oxygen from the coral tissues. By lowering the internal oxygen concentration, pulsation alleviates the problem of reduced affinity of ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO) to CO2 under conditions of high oxygen concentrations. The photosynthesis-respiration ratio of the pulsating H. fuscescens was markedly higher than the ratios reported for nonpulsating soft and stony corals. Although pulsation is commonly used for locomotion and filtration in marine mobile animals, its occurrence in sessile (bottom-attached) species is limited to members of the ancient phylum Cnidaria, where it is used to accelerate water and enhance physiological processes.

Evidence for Rhythmicity Pacemaker in the Calcification Process of Scleractinian Coral

NASA Astrophysics Data System (ADS)

Gutner-Hoch, Eldad; Schneider, Kenneth; Stolarski, Jaroslaw; Domart-Coulon, Isabelle; Yam, Ruth; Meibom, Anders; Shemesh, Aldo; Levy, Oren

2016-02-01

Reef-building scleractinian (stony) corals are among the most efficient bio-mineralizing organisms in nature. The calcification rate of scleractinian corals oscillates under ambient light conditions, with a cyclic, diurnal pattern. A fundamental question is whether this cyclic pattern is controlled by exogenous signals or by an endogenous ‘biological-clock’ mechanism, or both. To address this problem, we have studied calcification patterns of the Red Sea scleractinian coral Acropora eurystoma with frequent measurements of total alkalinity (AT) under different light conditions. Additionally, skeletal extension and ultra-structure of newly deposited calcium carbonate were elucidated with 86Sr isotope labeling analysis, combined with NanoSIMS ion microprobe and scanning electron microscope imaging. Our results show that the calcification process persists with its cyclic pattern under constant light conditions while dissolution takes place within one day of constant dark conditions, indicating that an intrinsic, light-entrained mechanism may be involved in controlling the calcification process in photosymbiotic corals.

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).

Transcriptome Analysis of the Scleractinian Coral Stylophora pistillata

PubMed Central

Salmon-Divon, Mali; Katzenellenbogen, Mark; Tambutté, Sylvie; Bertucci, Anthony; Hoegh-Guldberg, Ove; Deleury, Emeline; Allemand, Denis; Levy, Oren

2014-01-01

The principal architects of coral reefs are the scleractinian corals; these species are divided in two major clades referred to as “robust” and “complex” corals. Although the molecular diversity of the “complex” clade has received considerable attention, with several expressed sequence tag (EST) libraries and a complete genome sequence having been constructed, the “robust” corals have received far less attention, despite the fact that robust corals have been prominent focal points for ecological and physiological studies. Filling this gap affords important opportunities to extend these studies and to improve our understanding of the differences between the two major clades. Here, we present an EST library from Stylophora pistillata (Esper 1797) and systematically analyze the assembled transcripts compared to putative homologs from the complete proteomes of six well-characterized metazoans: Nematostella vectensis, Hydra magnipapillata, Caenorhabditis elegans, Drosophila melanogaster, Strongylocentrotus purpuratus, Ciona intestinalis and Homo sapiens. Furthermore, comparative analyses of the Stylophora pistillata ESTs were performed against several Cnidaria from the Scleractinia, Actiniaria and Hydrozoa, as well as against other stony corals separately. Functional characterization of S. pistillata transcripts into KOG/COG categories and further description of Wnt and bone morphogenetic protein (BMP) signaling pathways showed that the assembled EST library provides sufficient data and coverage. These features of this new library suggest considerable opportunities for extending our understanding of the molecular and physiological behavior of “robust” corals. PMID:24551124

Dynamics of lipid and fatty acid composition of shallow-water corals under thermal stress: an experimental approach

NASA Astrophysics Data System (ADS)

Imbs, A. B.; Yakovleva, I. M.

2012-03-01

Coral bleaching induces changes in lipid and fatty acid composition that result in low lipid content, reducing the likelihood of coral survival. Species-specific differences in the metabolism of lipid reserves may contribute to the differential resistance of corals under acute heat exposures. Here, we examined the dynamics of lipids and fatty acid abundance in corals subjected to short-term heat stress. The stony corals Acropora intermedia, Montipora digitata, and the soft coral Sinularia capitalis all showed a 60-75% decline in both storage and structural lipids. However, S. capitalis and M. digitata exhibited no significant change in the percentages of structural lipids (i.e., polar lipids and sterols) until they had lost 90-95% of their endosymbionts, whereas A. intermedia showed a rapid decline in structural lipids after a 50% loss of symbionts. After a 90-95% loss of symbionts under heat stress, all three corals showed a relative depletion of polyunsaturated fatty acids that had symbiont biomarkers, suggesting that polyunsaturated fatty acids were translocated from the symbiont to the coral host tissue.

Caribbean mesophotic coral ecosystems are unlikely climate change refugia.

PubMed

Smith, Tyler B; Gyory, Joanna; Brandt, Marilyn E; Miller, William J; Jossart, Jonathan; Nemeth, Richard S

2016-08-01

Deeper coral reefs experience reduced temperatures and light and are often shielded from localized anthropogenic stressors such as pollution and fishing. The deep reef refugia hypothesis posits that light-dependent stony coral species at deeper depths are buffered from thermal stress and will avoid bleaching-related mass mortalities caused by increasing sea surface temperatures under climate change. This hypothesis has not been tested because data collection on deeper coral reefs is difficult. Here we show that deeper (mesophotic) reefs, 30-75 m depth, in the Caribbean are not refugia because they have lower bleaching threshold temperatures than shallow reefs. Over two thermal stress events, mesophotic reef bleaching was driven by a bleaching threshold that declines 0.26 °C every +10 m depth. Thus, the main premise of the deep reef refugia hypothesis that cooler environments are protective is incorrect; any increase in temperatures above the local mean warmest conditions can lead to thermal stress and bleaching. Thus, relatively cooler temperatures can no longer be considered a de facto refugium for corals and it is likely that many deeper coral reefs are as vulnerable to climate change as shallow water reefs. © 2015 John Wiley & Sons Ltd.

Mitochondrial Genome Rearrangements in the Scleractinia/Corallimorpharia Complex: Implications for Coral Phylogeny

PubMed Central

Lin, Mei-Fang; Kitahara, Marcelo Visentini; Luo, Haiwei; Tracey, Dianne; Geller, Jonathan; Fukami, Hironobu; Miller, David John; Chen, Chaolun Allen

2014-01-01

Corallimorpharia is a small Order of skeleton-less animals that is closely related to the reef-building corals (Scleractinia) and of fundamental interest in the context of understanding the potential impacts of climate change in the future on coral reefs. The relationship between the nominal Orders Corallimorpharia and Scleractinia is controversial—the former is either the closest outgroup to the Scleractinia or alternatively is derived from corals via skeleton loss. This latter scenario, the “naked coral” hypothesis, is strongly supported by analyses based on mitochondrial (mt) protein sequences, whereas the former is equally strongly supported by analyses of mt nucleotide sequences. The “naked coral” hypothesis seeks to link skeleton loss in the putative ancestor of corallimorpharians with a period of elevated oceanic CO2 during the Cretaceous, leading to the idea that these skeleton-less animals may be harbingers for the fate of coral reefs under global climate change. In an attempt to better understand their evolutionary relationships, we examined mt genome organization in a representative range (12 species, representing 3 of the 4 extant families) of corallimorpharians and compared these patterns with other Hexacorallia. The most surprising finding was that mt genome organization in Corallimorphus profundus, a deep-water species that is the most scleractinian-like of all corallimorpharians on the basis of morphology, was much more similar to the common scleractinian pattern than to those of other corallimorpharians. This finding is consistent with the idea that C. profundus represents a key position in the coral <-> corallimorpharian transition. PMID:24769753

MAGNETIC TOPOLOGY OF A NAKED SUNSPOT: IS IT REALLY NAKED?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sainz Dalda, A.; Vargas Dominguez, S.; Tarbell, T. D.

The high spatial, temporal, and spectral resolution achieved by Hinode instruments gives much better understanding of the behavior of some elusive solar features, such as pores and naked sunspots. Their fast evolution and, in some cases, their small sizes have made their study difficult. The moving magnetic features (MMFs) have been studied during the last 40 years. They have been always associated with sunspots, especially with the penumbra. However, a recent observation of a naked sunspot (one with no penumbra) has shown MMF activity. The authors of this reported observation expressed their reservations about the explanation given to the bipolarmore » MMF activity as an extension of the penumbral filaments into the moat. How can this type of MMF exist when a penumbra does not? In this Letter, we study the full magnetic and (horizontal) velocity topology of the same naked sunspot, showing how the existence of a magnetic field topology similar to that observed in sunspots can explain these MMFs, even when the intensity map of the naked sunspot does not show a penumbra.« less

Phylogenetically diverse denitrifying and ammonia-oxidizing bacteria in corals Alcyonium gracillimum and Tubastraea coccinea.

PubMed

Yang, Shan; Sun, Wei; Zhang, Fengli; Li, Zhiyong

2013-10-01

To date, the association of coral-bacteria and the ecological roles of bacterial symbionts in corals remain largely unknown. In particular, little is known about the community components of bacterial symbionts of corals involved in the process of denitrification and ammonia oxidation. In this study, the nitrite reductase (nirS and nirK) and ammonia monooxygenase subunit A (amoA) genes were used as functional markers. Diverse bacteria with the potential to be active as denitrifiers and ammonia-oxidizing bacteria (AOB) were found in two East China Sea corals: stony coral Alcyonium gracillimum and soft coral Tubastraea coccinea. The 16S rRNA gene library analysis demonstrated different communities of bacterial symbionts in these two corals of the same location. Nitrite reductase nirK gene was found only in T. coccinea, while both nirK and nirS genes were detected in A. gracillimum, which might be the result of the presence of different bacterial symbionts in these two corals. AOB rather than ammonia-oxidizing archaea were detected in both corals, suggesting that AOB might play an important role in the ammonia oxidation process of the corals. This study indicates that the coral bacterial symbionts with the potential for nitrite reduction and ammonia oxidation might have multiple ecological roles in the coral holobiont, which promotes our understanding of bacteria-mediated nitrogen cycling in corals. To our knowledge, this study is the first assessment of the community structure and phylogenetic diversity of denitrifying bacteria and AOB in corals based on nirK, nirS, and amoA gene library analysis.

Corallimorpharians are not “naked corals”: insights into relationships between Scleractinia and Corallimorpharia from phylogenomic analyses

PubMed Central

Lin, Mei Fang; Chou, Wen Hwa; Kitahara, Marcelo V.; Chen, Chao Lun Allen

2016-01-01

Calcification is one of the most distinctive traits of scleractinian corals. Their hard skeletons form the substratum of reef ecosystems and confer on corals their remarkable diversity of shapes. Corallimorpharians are non-calcifying, close relatives of scleractinian corals, and the evolutionary relationship between these two groups is key to understanding the evolution of calcification in the coral lineage. One pivotal question is whether scleractinians are a monophyletic group, paraphyly being an alternative possibility if corallimorpharians are corals that have lost their ability to calcify, as is implied by the “naked-coral” hypothesis. Despite major efforts, relationships between scleractinians and corallimorpharians remain equivocal and controversial. Although the complete mitochondrial genomes of a range of scleractinians and corallimorpharians have been obtained, heterogeneity in composition and evolutionary rates means that mitochondrial sequences are insufficient to understand the relationship between these two groups. To overcome these limitations, transcriptome data were generated for three representative corallimorpharians. These were used in combination with sequences available for a representative range of scleractinians to identify 291 orthologous single copy protein-coding nuclear markers. Unlike the mitochondrial sequences, these nuclear markers do not display any distinct compositional bias in their nucleotide or amino-acid sequences. A range of phylogenomic approaches congruently reveal a topology consistent with scleractinian monophyly and corallimorpharians as the sister clade of scleractinians. PMID:27761308

Oxygen isotope variation in stony-iron meteorites.

PubMed

Greenwood, R C; Franchi, I A; Jambon, A; Barrat, J A; Burbine, T H

2006-09-22

Asteroidal material, delivered to Earth as meteorites, preserves a record of the earliest stages of planetary formation. High-precision oxygen isotope analyses for the two major groups of stony-iron meteorites (main-group pallasites and mesosiderites) demonstrate that each group is from a distinct asteroidal source. Mesosiderites are isotopically identical to the howardite-eucrite-diogenite clan and, like them, are probably derived from the asteroid 4 Vesta. Main-group pallasites represent intermixed core-mantle material from a single disrupted asteroid and have no known equivalents among the basaltic meteorites. The stony-iron meteorites demonstrate that intense asteroidal deformation accompanied planetary accretion in the early Solar System.

Stepwise Evolution of Coral Biomineralization Revealed with Genome-Wide Proteomics and Transcriptomics

PubMed Central

Sawada, Hitoshi; Satoh, Noriyuki

2016-01-01

Despite the importance of stony corals in many research fields related to global issues, such as marine ecology, climate change, paleoclimatogy, and metazoan evolution, very little is known about the evolutionary origin of coral skeleton formation. In order to investigate the evolution of coral biomineralization, we have identified skeletal organic matrix proteins (SOMPs) in the skeletal proteome of the scleractinian coral, Acropora digitifera, for which large genomic and transcriptomic datasets are available. Scrupulous gene annotation was conducted based on comparisons of functional domain structures among metazoans. We found that SOMPs include not only coral-specific proteins, but also protein families that are widely conserved among cnidarians and other metazoans. We also identified several conserved transmembrane proteins in the skeletal proteome. Gene expression analysis revealed that expression of these conserved genes continues throughout development. Therefore, these genes are involved not only skeleton formation, but also in basic cellular functions, such as cell-cell interaction and signaling. On the other hand, genes encoding coral-specific proteins, including extracellular matrix domain-containing proteins, galaxins, and acidic proteins, were prominently expressed in post-settlement stages, indicating their role in skeleton formation. Taken together, the process of coral skeleton formation is hypothesized as: 1) formation of initial extracellular matrix between epithelial cells and substrate, employing pre-existing transmembrane proteins; 2) additional extracellular matrix formation using novel proteins that have emerged by domain shuffling and rapid molecular evolution and; 3) calcification controlled by coral-specific SOMPs. PMID:27253604

Farm Education at Stony Kill.

ERIC Educational Resources Information Center

Parisio, Richard

1986-01-01

Describes typical winter farm lessons for students visiting Stony Kill Farm Environmental Education Center located 70 miles north of New York City: butter and corncake making, soil erosion experiments, dissecting and growing seeds. Emphasizes major theme of conservation of farmland from destructive farming practices and careless development. (NEC)

Localization of early germ cells in a stony coral, Euphyllia ancora: potential implications for a germline stem cell system in coral gametogenesis

NASA Astrophysics Data System (ADS)

Shikina, Shinya; Chung, Yi-Jou; Wang, Hsiang-Ming; Chiu, Yi-Ling; Shao, Zih-Fang; Lee, Yan-Horn; Chang, Ching-Fong

2015-06-01

Most corals exhibit annual or multiple gametogenic cycles. Thus far, coral gametogenesis has been studied in many species and locations during the past three decades; however, currently, only a few papers exist that describe the origin of germ cells, such as germline stem cells (GSCs), which support the continuous production of gametes in every reproductive cycle. To address this issue, in this study, we focused on and identified piwi gene, which has been used as a marker of germline cells, including GSCs, in various metazoans, in a scleractinian coral, Euphyllia ancora. Reverse-transcription PCR and Western blotting analyses revealed that E. ancora piwi-like ( Eapiwi) is expressed in mesentery tissues where the sites of gametogenesis are located for both sexes. Immunohistochemistry with a specific antibody against Eapiwi revealed strong immunoreactivity in the spermatogonia in males and in the oogonia and early oocytes in females, demonstrating that Eapiwi could be used as an early germ cell marker in E. ancora. Subsequent immunohistochemical analyses regarding the spatial and temporal distribution patterns of early germ cells in mesentery tissues revealed that early germ cells were present throughout the year in the mesentery tissue we examined, regardless of the sexual reproductive cycle. In particular, small numbers of early germ cells were observed in specific sites of mesentery tissues with fully matured gonads in both sexes. These early germ cells were not released together with mature gametes during the spawning period and remained in the mesentery tissues. These results suggested that these early germ cells most likely serve as a reservoir of germline cells and that some of these cells would produce differentiated germ cells for the upcoming sexual reproduction period; hence, these cells would function as GSCs. Our data provide new information for understanding continuous gamete production in corals.

Benefit of pulsation in soft corals

PubMed Central

Kremien, Maya; Shavit, Uri; Mass, Tali; Genin, Amatzia

2013-01-01

Soft corals of the family Xeniidae exhibit a unique, rhythmic pulsation of their tentacles (Movie S1), first noted by Lamarck nearly 200 y ago. However, the adaptive benefit of this perpetual, energetically costly motion is poorly understood. Using in situ underwater particle image velocimetry, we found that the pulsation motions thrust water upward and enhance mixing across the coral–water boundary layer. The induced upward motion effectively prevents refiltration of water by neighboring polyps, while the intensification of mixing, together with the upward flow, greatly enhances the coral’s photosynthesis. A series of controlled laboratory experiments with the common xeniid coral Heteroxenia fuscescens showed that the net photosynthesis rate during pulsation was up to an order of magnitude higher than during the coral’s resting, nonpulsating state. This enhancement diminished when the concentration of oxygen in the ambient water was artificially raised, indicating that the enhancement of photosynthesis was due to a greater efflux of oxygen from the coral tissues. By lowering the internal oxygen concentration, pulsation alleviates the problem of reduced affinity of ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO) to CO2 under conditions of high oxygen concentrations. The photosynthesis–respiration ratio of the pulsating H. fuscescens was markedly higher than the ratios reported for nonpulsating soft and stony corals. Although pulsation is commonly used for locomotion and filtration in marine mobile animals, its occurrence in sessile (bottom-attached) species is limited to members of the ancient phylum Cnidaria, where it is used to accelerate water and enhance physiological processes. PMID:23610420

Metabarcoding dietary analysis of coral dwelling predatory fish demonstrates the minor contribution of coral mutualists to their highly partitioned, generalist diet

PubMed Central

Meyer, Christopher P.; Mills, Suzanne C.

2015-01-01

Understanding the role of predators in food webs can be challenging in highly diverse predator/prey systems composed of small cryptic species. DNA based dietary analysis can supplement predator removal experiments and provide high resolution for prey identification. Here we use a metabarcoding approach to provide initial insights into the diet and functional role of coral-dwelling predatory fish feeding on small invertebrates. Fish were collected in Moorea (French Polynesia) where the BIOCODE project has generated DNA barcodes for numerous coral associated invertebrate species. Pyrosequencing data revealed a total of 292 Operational Taxonomic Units (OTU) in the gut contents of the arc-eye hawkfish (Paracirrhites arcatus), the flame hawkfish (Neocirrhites armatus) and the coral croucher (Caracanthus maculatus). One hundred forty-nine (51%) of them had species-level matches in reference libraries (>98% similarity) while 76 additional OTUs (26%) could be identified to higher taxonomic levels. Decapods that have a mutualistic relationship with Pocillopora and are typically dominant among coral branches, represent a minor contribution of the predators’ diets. Instead, predators mainly consumed transient species including pelagic taxa such as copepods, chaetognaths and siphonophores suggesting non random feeding behavior. We also identified prey species known to have direct negative interactions with stony corals, such as Hapalocarcinus sp, a gall crab considered a coral parasite, as well as species of vermetid snails known for their deleterious effects on coral growth. Pocillopora DNA accounted for 20.8% and 20.1% of total number of sequences in the guts of the flame hawkfish and coral croucher but it was not detected in the guts of the arc-eye hawkfish. Comparison of diets among the three fishes demonstrates remarkable partitioning with nearly 80% of prey items consumed by only one predator. Overall, the taxonomic resolution provided by the metabarcoding approach

Metabarcoding dietary analysis of coral dwelling predatory fish demonstrates the minor contribution of coral mutualists to their highly partitioned, generalist diet.

PubMed

Leray, Matthieu; Meyer, Christopher P; Mills, Suzanne C

2015-01-01

Understanding the role of predators in food webs can be challenging in highly diverse predator/prey systems composed of small cryptic species. DNA based dietary analysis can supplement predator removal experiments and provide high resolution for prey identification. Here we use a metabarcoding approach to provide initial insights into the diet and functional role of coral-dwelling predatory fish feeding on small invertebrates. Fish were collected in Moorea (French Polynesia) where the BIOCODE project has generated DNA barcodes for numerous coral associated invertebrate species. Pyrosequencing data revealed a total of 292 Operational Taxonomic Units (OTU) in the gut contents of the arc-eye hawkfish (Paracirrhites arcatus), the flame hawkfish (Neocirrhites armatus) and the coral croucher (Caracanthus maculatus). One hundred forty-nine (51%) of them had species-level matches in reference libraries (>98% similarity) while 76 additional OTUs (26%) could be identified to higher taxonomic levels. Decapods that have a mutualistic relationship with Pocillopora and are typically dominant among coral branches, represent a minor contribution of the predators' diets. Instead, predators mainly consumed transient species including pelagic taxa such as copepods, chaetognaths and siphonophores suggesting non random feeding behavior. We also identified prey species known to have direct negative interactions with stony corals, such as Hapalocarcinus sp, a gall crab considered a coral parasite, as well as species of vermetid snails known for their deleterious effects on coral growth. Pocillopora DNA accounted for 20.8% and 20.1% of total number of sequences in the guts of the flame hawkfish and coral croucher but it was not detected in the guts of the arc-eye hawkfish. Comparison of diets among the three fishes demonstrates remarkable partitioning with nearly 80% of prey items consumed by only one predator. Overall, the taxonomic resolution provided by the metabarcoding approach

A snapshot of a coral "holobiont": a transcriptome assembly of the scleractinian coral, porites, captures a wide variety of genes from both the host and symbiotic zooxanthellae.

PubMed

Shinzato, Chuya; Inoue, Mayuri; Kusakabe, Makoto

2014-01-01

Massive scleractinian corals of the genus Porites are important reef builders in the Indo-Pacific, and they are more resistant to thermal stress than other stony corals, such as the genus Acropora. Because coral health and survival largely depend on the interaction between a coral host and its symbionts, it is important to understand the molecular interactions of an entire "coral holobiont". We simultaneously sequenced transcriptomes of Porites australiensis and its symbionts using the Illumina Hiseq2000 platform. We obtained 14.3 Gbp of sequencing data and assembled it into 74,997 contigs (average: 1,263 bp, N50 size: 2,037 bp). We successfully distinguished contigs originating from the host (Porites) and the symbiont (Symbiodinium) by aligning nucleotide sequences with the decoded Acropora digitifera and Symbiodinium minutum genomes. In contrast to previous coral transcriptome studies, at least 35% of the sequences were found to have originated from the symbionts, indicating that it is possible to analyze both host and symbiont transcriptomes simultaneously. Conserved protein domain and KEGG analyses showed that the dataset contains broad gene repertoires of both Porites and Symbiodinium. Effective utilization of sequence reads revealed that the polymorphism rate in P. australiensis is 1.0% and identified the major symbiotic Symbiodinium as Type C15. Analyses of amino acid biosynthetic pathways suggested that this Porites holobiont is probably able to synthesize most of the common amino acids and that Symbiodinium is potentially able to provide essential amino acids to its host. We believe this to be the first molecular evidence of complementarity in amino acid metabolism between coral hosts and their symbionts. We successfully assembled genes originating from both the host coral and the symbiotic Symbiodinium to create a snapshot of the coral holobiont transcriptome. This dataset will facilitate a deeper understanding of molecular mechanisms of coral symbioses

Microarray analysis identifies candidate genes for key roles in coral development

PubMed Central

Grasso, Lauretta C; Maindonald, John; Rudd, Stephen; Hayward, David C; Saint, Robert; Miller, David J; Ball, Eldon E

2008-01-01

Background Anthozoan cnidarians are amongst the simplest animals at the tissue level of organization, but are surprisingly complex and vertebrate-like in terms of gene repertoire. As major components of tropical reef ecosystems, the stony corals are anthozoans of particular ecological significance. To better understand the molecular bases of both cnidarian development in general and coral-specific processes such as skeletogenesis and symbiont acquisition, microarray analysis was carried out through the period of early development – when skeletogenesis is initiated, and symbionts are first acquired. Results Of 5081 unique peptide coding genes, 1084 were differentially expressed (P ≤ 0.05) in comparisons between four different stages of coral development, spanning key developmental transitions. Genes of likely relevance to the processes of settlement, metamorphosis, calcification and interaction with symbionts were characterised further and their spatial expression patterns investigated using whole-mount in situ hybridization. Conclusion This study is the first large-scale investigation of developmental gene expression for any cnidarian, and has provided candidate genes for key roles in many aspects of coral biology, including calcification, metamorphosis and symbiont uptake. One surprising finding is that some of these genes have clear counterparts in higher animals but are not present in the closely-related sea anemone Nematostella. Secondly, coral-specific processes (i.e. traits which distinguish corals from their close relatives) may be analogous to similar processes in distantly related organisms. This first large-scale application of microarray analysis demonstrates the potential of this approach for investigating many aspects of coral biology, including the effects of stress and disease. PMID:19014561

The role of floridoside in osmoadaptation of coral-associated algal endosymbionts to high-salinity conditions

PubMed Central

Ochsenkühn, Michael A.; Röthig, Till; D’Angelo, Cecilia; Wiedenmann, Jörg; Voolstra, Christian R.

2017-01-01

The endosymbiosis between Symbiodinium dinoflagellates and stony corals provides the foundation of coral reef ecosystems. The survival of these ecosystems is under threat at a global scale, and better knowledge is needed to conceive strategies for mitigating future reef loss. Environmental disturbance imposing temperature, salinity, and nutrient stress can lead to the loss of the Symbiodinium partner, causing so-called coral bleaching. Some of the most thermotolerant coral-Symbiodinium associations occur in the Persian/Arabian Gulf and the Red Sea, which also represent the most saline coral habitats. We studied whether Symbiodinium alter their metabolite content in response to high-salinity environments. We found that Symbiodinium cells exposed to high salinity produced high levels of the osmolyte 2-O-glycerol-α-d-galactopyranoside (floridoside), both in vitro and in their coral host animals, thereby increasing their capacity and, putatively, the capacity of the holobiont to cope with the effects of osmotic stress in extreme environments. Given that floridoside has been previously shown to also act as an antioxidant, this osmolyte may serve a dual function: first, to serve as a compatible organic osmolyte accumulated by Symbiodinium in response to elevated salinities and, second, to counter reactive oxygen species produced as a consequence of potential salinity and heat stress. PMID:28835914

A Snapshot of a Coral “Holobiont”: A Transcriptome Assembly of the Scleractinian Coral, Porites, Captures a Wide Variety of Genes from Both the Host and Symbiotic Zooxanthellae

PubMed Central

Shinzato, Chuya; Inoue, Mayuri; Kusakabe, Makoto

2014-01-01

Massive scleractinian corals of the genus Porites are important reef builders in the Indo-Pacific, and they are more resistant to thermal stress than other stony corals, such as the genus Acropora. Because coral health and survival largely depend on the interaction between a coral host and its symbionts, it is important to understand the molecular interactions of an entire “coral holobiont”. We simultaneously sequenced transcriptomes of Porites australiensis and its symbionts using the Illumina Hiseq2000 platform. We obtained 14.3 Gbp of sequencing data and assembled it into 74,997 contigs (average: 1,263 bp, N50 size: 2,037 bp). We successfully distinguished contigs originating from the host (Porites) and the symbiont (Symbiodinium) by aligning nucleotide sequences with the decoded Acropora digitifera and Symbiodinium minutum genomes. In contrast to previous coral transcriptome studies, at least 35% of the sequences were found to have originated from the symbionts, indicating that it is possible to analyze both host and symbiont transcriptomes simultaneously. Conserved protein domain and KEGG analyses showed that the dataset contains broad gene repertoires of both Porites and Symbiodinium. Effective utilization of sequence reads revealed that the polymorphism rate in P. australiensis is 1.0% and identified the major symbiotic Symbiodinium as Type C15. Analyses of amino acid biosynthetic pathways suggested that this Porites holobiont is probably able to synthesize most of the common amino acids and that Symbiodinium is potentially able to provide essential amino acids to its host. We believe this to be the first molecular evidence of complementarity in amino acid metabolism between coral hosts and their symbionts. We successfully assembled genes originating from both the host coral and the symbiotic Symbiodinium to create a snapshot of the coral holobiont transcriptome. This dataset will facilitate a deeper understanding of molecular mechanisms of coral

Naked singularity resolution in cylindrical collapse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurita, Yasunari; Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, 606-8502; Nakao, Ken-ichi

In this paper, we study the gravitational collapse of null dust in cylindrically symmetric spacetime. The naked singularity necessarily forms at the symmetry axis. We consider the situation in which null dust is emitted again from the naked singularity formed by the collapsed null dust and investigate the backreaction by this emission for the naked singularity. We show a very peculiar but physically important case in which the same amount of null dust as that of the collapsed one is emitted from the naked singularity as soon as the ingoing null dust hits the symmetry axis and forms the nakedmore » singularity. In this case, although this naked singularity satisfies the strong curvature condition by Krolak (limiting focusing condition), geodesics which hit the singularity can be extended uniquely across the singularity. Therefore, we may say that the collapsing null dust passes through the singularity formed by itself and then leaves for infinity. Finally, the singularity completely disappears and the flat spacetime remains.« less

Spatial and species variations in bacterial communities associated with corals from the Red Sea as revealed by pyrosequencing.

PubMed

Lee, On On; Yang, Jiangke; Bougouffa, Salim; Wang, Yong; Batang, Zenon; Tian, Renmao; Al-Suwailem, Abdulaziz; Qian, Pei-Yuan

2012-10-01

Microbial associations with corals are common and are most likely symbiotic, although their diversity and relationships with environmental factors and host species remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with three stony Scleractinea and two soft Octocorallia corals from three locations in the Red Sea. Our results revealed highly diverse bacterial communities in the Red Sea corals, with more than 600 ribotypes detected and up to 1,000 species estimated from a single coral species. Altogether, 21 bacterial phyla were recovered from the corals, of which Gammaproteobacteria was the most dominant group, and Chloroflexi, Chlamydiae, and the candidate phylum WS3 were reported in corals for the first time. The associated bacterial communities varied greatly with location, where environmental conditions differed significantly. Corals from disturbed areas appeared to share more similar bacterial communities, but larger variations in community structures were observed between different coral species from pristine waters. Ordination methods identified salinity and depth as the most influential parameters affecting the abundance of Vibrio, Pseudoalteromonas, Serratia, Stenotrophomonas, Pseudomonas, and Achromobacter in the corals. On the other hand, bacteria such as Chloracidobacterium and Endozoicomonas were more sensitive to the coral species, suggesting that the host species type may be influential in the associated bacterial community, as well. The combined influences of the coral host and environmental factors on the associated microbial communities are discussed. This study represents the first comparative study using tag-pyrosequencing technology to investigate the bacterial communities in Red Sea corals.

Spatial and Species Variations in Bacterial Communities Associated with Corals from the Red Sea as Revealed by Pyrosequencing

PubMed Central

Lee, On On; Yang, Jiangke; Bougouffa, Salim; Wang, Yong; Batang, Zenon; Tian, Renmao; Al-Suwailem, Abdulaziz

2012-01-01

Microbial associations with corals are common and are most likely symbiotic, although their diversity and relationships with environmental factors and host species remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with three stony Scleractinea and two soft Octocorallia corals from three locations in the Red Sea. Our results revealed highly diverse bacterial communities in the Red Sea corals, with more than 600 ribotypes detected and up to 1,000 species estimated from a single coral species. Altogether, 21 bacterial phyla were recovered from the corals, of which Gammaproteobacteria was the most dominant group, and Chloroflexi, Chlamydiae, and the candidate phylum WS3 were reported in corals for the first time. The associated bacterial communities varied greatly with location, where environmental conditions differed significantly. Corals from disturbed areas appeared to share more similar bacterial communities, but larger variations in community structures were observed between different coral species from pristine waters. Ordination methods identified salinity and depth as the most influential parameters affecting the abundance of Vibrio, Pseudoalteromonas, Serratia, Stenotrophomonas, Pseudomonas, and Achromobacter in the corals. On the other hand, bacteria such as Chloracidobacterium and Endozoicomonas were more sensitive to the coral species, suggesting that the host species type may be influential in the associated bacterial community, as well. The combined influences of the coral host and environmental factors on the associated microbial communities are discussed. This study represents the first comparative study using tag-pyrosequencing technology to investigate the bacterial communities in Red Sea corals. PMID:22865078

Deep-convection events foster carbonate ion reduction in deep coral reefs

NASA Astrophysics Data System (ADS)

Perez, Fiz F.; Fontela, Marcos; Garcia-Ibañez, Maribel I.; Lherminier, Pascale; Zunino, Patricia; de la Paz, Mercedes; Padín, Xose A.; Alonso-Pérez, Fernando; Velo, Anton; Guallart, Elisa F.; Mercier, Herle

2017-04-01

Since millennial times, water mass circulation and deep-convection events have been transforming warm upper waters at high latitudes into cold and well-oxygenated deep waters. These processes have filled the deep North Atlantic Ocean with waters moderately saturated in calcium carbonate, thus promoting the growth of stony corals, which are hotspots of biodiversity. During the Anthropocene, the meridional circulation has been conveying cumulative amounts of more acidified waters with lower calcium carbonate saturation levels due to the incorporation of anthropogenic carbon dioxide, with very harsh conditions for deep cold-water corals projected by 2100. We evaluate the diminution of calcium carbonate saturation levels (aragonite form) due to the increase in anthropogenic carbon dioxide during the last two decades (2002-2016). We observe a strong decrease in the aragonite saturation levels concomitant with the reduction in the volume transport of aragonite-saturated waters. We estimate a 30-35% reduction in the transport of ion carbonate excess over the saturation levels with respect to the natural carbon cycle for the period 2002-2016. This reduction is associated with an increase in the downward transport of hydrogen ions. We also observe a heaving of the aragonite saturation horizons during the last 25 years, which is estimated at 6 m year-1 for the deep waters and 12-14 m year-1 for the intermediated waters. The harsh winters of 2015 and 2016 have fostered the fast addition of more acidified water into the lower layers of the North Atlantic through deep-convection events. In the future scenario of 2oC warming, the anthropogenic carbon dioxide in the water column would be double than today and the associated transport of hydrogen ions towards the bottom water would reduce the aragonite saturation levels to 60-80% with respect to preindustrial levels. This reduction in the aragonite saturation levels would suppose a strong diminution of the North Atlantic habitats

Naked singularity, firewall, and Hawking radiation.

PubMed

Zhang, Hongsheng

2017-06-21

Spacetime singularity has always been of interest since the proof of the Penrose-Hawking singularity theorem. Naked singularity naturally emerges from reasonable initial conditions in the collapsing process. A recent interesting approach in black hole information problem implies that we need a firewall to break the surplus entanglements among the Hawking photons. Classically, the firewall becomes a naked singularity. We find some vacuum analytical solutions in R n -gravity of the firewall-type and use these solutions as concrete models to study the naked singularities. By using standard quantum theory, we investigate the Hawking radiation emitted from the black holes with naked singularities. Here we show that the singularity itself does not destroy information. A unitary quantum theory works well around a firewall-type singularity. We discuss the validity of our result in general relativity. Further our result demonstrates that the temperature of the Hawking radiation still can be expressed in the form of the surface gravity divided by 2π. This indicates that a naked singularity may not compromise the Hakwing evaporation process.

Reef corals of Johnston Atoll: one of the world's most isolated reefs

NASA Astrophysics Data System (ADS)

Maragos, James E.; Jokiel, Paul L.

1986-01-01

Johnston Atoll lies 800 km southwest of the nearest reefs of Hawaii and over 1,500 km from other shallow reefs to the south and west. Only 33 species and 16 genera and subgenera of shallow water stony corals have been reported from the atoll. Endemic species are absent despite Johnston's great age and favorable environment. With few exceptions, only species with broad geographic distribution are represented. Factors contributing to the low number of species are remoteness, the atoll's small size, lack of favorable currents to transport larvae from the southwest Pacific, lack of reef “stepping stones” in the region since the Cretaceous, possible defaunation during eustatic sea-level rise and fall, and possible drowning from tectonic subsidence or tilting. The species list shows strongest affinity with that of Hawaii, but some unexpected discontinuities occur. Despite low species diversity, coral coverage is extremely high in most environments.

Breakdown of coral colonial form under reduced pH conditions is initiated in polyps and mediated through apoptosis

PubMed Central

Kvitt, Hagit; Kramarsky-Winter, Esti; Maor-Landaw, Keren; Zandbank, Keren; Kushmaro, Ariel; Rosenfeld, Hanna; Fine, Maoz; Tchernov, Dan

2015-01-01

Certain stony corals can alternate between a calcifying colonial form and noncalcifying solitary polyps, supporting the hypothesis that corals have survived through geologic timescale periods of unfavorable calcification conditions. However, the mechanisms enabling this biological plasticity are yet to be identified. Here we show that incubation of two coral species (Pocillopora damicornis and Oculina patagonica) under reduced pH conditions (pH 7.2) simulating past ocean acidification induce tissue-specific apoptosis that leads to the dissociation of polyps from coenosarcs. This in turn leads to the breakdown of the coenosarc and, as a consequence, to loss of coloniality. Our data show that apoptosis is initiated in the polyps and that once dissociation between polyp and coenosarc terminates, apoptosis subsides. After reexposure of the resulting solitary polyps to normal pH (pH 8.2), both coral species regenerated coenosarc tissues and resumed calcification. These results indicate that regulation of coloniality is under the control of the polyp, the basic modular unit of the colony. A mechanistic explanation for several key evolutionarily important phenomena that occurred throughout coral evolution is proposed, including mechanisms that permitted species to survive the third tier of mass extinctions. PMID:25646434

Naked singularities as particle accelerators. II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patil, Mandar; Joshi, Pankaj S.; Malafarina, Daniele

We generalize here our earlier results on particle acceleration by naked singularities. We showed recently [M. Patil and P. S. Joshi, Phys. Rev. D 82, 104049 (2010).] that the naked singularities that form due to the gravitational collapse of massive stars provide a suitable environment where particles could get accelerated and collide at arbitrarily high center-of-mass energies. However, we focused there only on the spherically symmetric gravitational collapse models, which were also assumed to be self-similar. In this paper, we broaden and generalize the result to all gravitational collapse models leading to the formation of a naked singularity as themore » final state of collapse, evolving from a regular initial data, without making any prior restrictive assumptions about the spacetime symmetries such as above. We show that, when the particles interact and collide near the Cauchy horizon, the energy of collision in the center-of-mass frame will be arbitrarily high, thus offering a window to the Planck scale physics. We also consider the issue of various possible physical mechanisms of generation of such very high-energy particles from the vicinity of naked singularity. We then construct a model of gravitational collapse to a timelike naked singularity to demonstrate the working of these ideas, where the pressure is allowed to be negative, but the energy conditions are respected. We show that a finite amount of mass-energy density has to be necessarily radiated away from the vicinity of the naked singularity as the collapse evolves. Therefore, the nature of naked singularities, both at the classical and quantum level, could play an important role in the process of particle acceleration, explaining the occurrence of highly energetic outgoing particles in the vicinity of the Cauchy horizon that participate in extreme high-energy collisions.« less

Gravitational lensing by rotating naked singularities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gyulchev, Galin N.; Yazadjiev, Stoytcho S.; Institut fuer Theoretische Physik, Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen

We model massive compact objects in galactic nuclei as stationary, axially symmetric naked singularities in the Einstein-massless scalar field theory and study the resulting gravitational lensing. In the weak deflection limit we study analytically the position of the two weak field images, the corresponding signed and absolute magnifications as well as the centroid up to post-Newtonian order. We show that there are static post-Newtonian corrections to the signed magnification and their sum as well as to the critical curves, which are functions of the scalar charge. The shift of the critical curves as a function of the lens angular momentummore » is found, and it is shown that they decrease slightly for the weakly naked and vastly for the strongly naked singularities with the increase of the scalar charge. The pointlike caustics drift away from the optical axis and do not depend on the scalar charge. In the strong deflection limit approximation, we compute numerically the position of the relativistic images and their separability for weakly naked singularities. All of the lensing quantities are compared to particular cases as Schwarzschild and Kerr black holes as well as Janis-Newman-Winicour naked singularities.« less

Naked singularities as particle accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patil, Mandar; Joshi, Pankaj S.

We investigate here the particle acceleration by naked singularities to arbitrarily high center of mass energies. Recently it has been suggested that black holes could be used as particle accelerators to probe the Planck scale physics. We show that the naked singularities serve the same purpose and probably would do better than their black hole counterparts. We focus on the scenario of a self-similar gravitational collapse starting from a regular initial data, leading to the formation of a globally naked singularity. It is seen that when particles moving along timelike geodesics interact and collide near the Cauchy horizon, the energymore » of collision in the center of mass frame will be arbitrarily high, thus offering a window to Planck scale physics.« less

Introduction to the Stony Brook Library: A Self-Paced Workbook for INT 150.

ERIC Educational Resources Information Center

Baum, Nathan; And Others

Designed to acquaint Stony Brook students with the facilities and resources of their library, this workbook in library skills is used in conjunction with courses offered at the State University of New York at Stony Brook. It is organized into chapters dealing with types of materials rather than by area of the library. Each chapter has an…

Thermally tolerant corals have limited capacity to acclimatize to future warming.

PubMed

Rodolfo-Metalpa, Riccardo; Hoogenboom, Mia O; Rottier, Cécile; Ramos-Esplá, Alfonso; Baker, Andrew C; Fine, Maoz; Ferrier-Pagès, Christine

2014-10-01

Thermal stress affects organism performance differently depending on the ambient temperature to which they are acclimatized, which varies along latitudinal gradients. This study investigated whether differences in physiological responses to temperature are consistent with regional differences in temperature regimes for the stony coral Oculina patagonica. To resolve this question, we experimentally assessed how colonies originating from four different locations characterized by >3 °C variation in mean maximum annual temperature responded to warming from 20 to 32 °C. We assessed plasticity in symbiont identity, density, and photosynthetic properties, together with changes in host tissue biomass. Results show that, without changes in the type of symbiont hosted by coral colonies, O. patagonica has limited capacity to acclimatize to future warming. We found little evidence of variation in overall thermal tolerance, or in thermal optima, in response to spatial variation in ambient temperature. Given that the invader O. patagonica is a relatively new member of the Mediterranean coral fauna, our results also suggest that coral populations may need to remain isolated for a long period of time for thermal adaptation to potentially take place. Our study indicates that for O. patagonica, mortality associated with thermal stress manifests primarily through tissue breakdown under moderate but prolonged warming (which does not impair symbiont photosynthesis and, therefore, does not lead to bleaching). Consequently, projected global warming is likely to cause repeat incidents of partial and whole colony mortality and might drive a gradual range contraction of Mediterranean corals. © 2014 John Wiley & Sons Ltd.

Distributions and habitat associations of deep-water corals in Norfolk and Baltimore Canyons, Mid-Atlantic Bight, USA

NASA Astrophysics Data System (ADS)

Brooke, S. D.; Watts, M. W.; Heil, A. D.; Rhode, M.; Mienis, F.; Duineveld, G. C. A.; Davies, A. J.; Ross, S. W.

2017-03-01

A multi-disciplinary study of two major submarine canyons, Baltimore Canyon and Norfolk Canyon, off the US mid-Atlantic coast focused on the ecology and biology of canyon habitats, particularly those supporting deep-sea corals. Historical data on deep-sea corals from these canyons were sparse with less than 750 records for the mid-Atlantic region, with most being soft sediment species. This study substantially increased the number of deep-sea coral records for the target canyons and the region. Large gorgonians were the dominant structure-forming coral taxa on exposed hard substrates, but several species of scleractinians were also documented, including first observations of Lophelia pertusa in the mid-Atlantic Bight region. Coral distribution varied within and between the two canyons, with greater abundance of the octocoral Paragorgia arborea in Baltimore Canyon, and higher occurrence of stony corals in Norfolk Canyon; these observations reflect the differences in environmental conditions, particularly turbidity, between the canyons. Some species have a wide distribution (e.g., P. arborea, Primnoa resedaeformis, Anthothela grandiflora), while others are limited to certain habitat types and/or depth zones (e.g., Paramuricea placomus, L. pertusa, Solenosmilia variabilis). The distribution of a species is driven by a combination of factors, which include availability of appropriate physical structure and environmental conditions. Although the diversity of the structure-forming corals (gorgonians, branching scleractinians and large anemones) was low, many areas of both canyons supported high coral abundance and a diverse coral-associated community. The canyons provide suitable habitat for the development of deep-sea coral communities that is not readily available elsewhere on the sedimented shelf and slope of the Mid-Atlantic Bight.

Investigation of trophic ecology in Newfoundland cold-water deep-sea corals using lipid class and fatty acid analyses

NASA Astrophysics Data System (ADS)

Salvo, Flora; Hamoutene, Dounia; Hayes, Vonda E. Wareham; Edinger, Evan N.; Parrish, Christopher C.

2018-03-01

The trophic behavior of some deep-sea Newfoundland cold-water corals was explored using fatty acid (FA) and lipid profiles. No significant effect of geographic location and/or depth was identified in lipid or FA composition. However, differences were detected between and within taxon groups in hexa- or octocoral subclasses. Phospholipids constituted the main lipid class in all groups except black-thorny corals which had less structural lipids likely due to their morphology (stiff axes) and slower growth rates. Within each subclass, major differences in the identity of dominant FAs were detected at the order level, whereas differences between species and taxon groups of the same order were mainly driven by a variation in proportions of the dominant FA. Soft corals and gorgonians (Order Alcyonacea) were close in composition and are likely relying on phytodetritus resulting from algae, macrophytes and/or foraminifera, while sea pens (Order Pennatulacea) seem to consume more diatoms and/or herbivorous zooplankton with the exception of Pennatula sp. In the hexacoral subclass, black-thorny corals ( Stauropathes arctica) differed significantly from the stony-cup corals ( Flabellum alabastrum); S. arctica was seemingly more carnivorous (zooplankton markers) than F. alabastrum, which appears omnivorous (phyto- and zooplankton markers). Our results suggest that deep-sea corals are not as opportunistic as expected but have some selective feeding associated with taxonomy.

Bioassessment Tools for Stony Corals: Monitoring Approaches and Proposed Sampling Plan for the U.S. Virgin Islands

EPA Science Inventory

This document describes three general approaches to the design of a sampling plan for biological monitoring of coral reefs. Status assessment, trend detection and targeted monitoring each require a different approach to site selection and statistical analysis. For status assessm...

Cosmic dust particle densities - Evidence for two populations of stony micrometeorites

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Sutton, S. R.

1991-01-01

The existence of two populations of stony micrometeorites of distinctly different densities would result in significantly different orbital evolution properties for particles from each group. The densities inferred from deceleration of meteors in the earth's atmosphere suggest a substantial amount of the meteoric material has densities of 1 g/cu cm or less (Verniani, 1973). However, measurements of microcraters on lunar rock surfaces led Brownlee et al. (1973) to the conclusion that most micrometeoroids impacting the moon had densities in the 2-4 g/cu cm range, and low-density micrometeoroids were rare. The recovery of stony micrometeorites from the earth's stratosphere after atmospheric deceleration provides the opportunity to resolve the discrepancies. Here, the densities of 12 stony micrometeorites are determined, using synchrotron X-ray fluorescence to infer the particle mass and optical microscope measurements of the volumes. The particles fall into two distinct density groups, with mean values of 0.6 and 1.9 g/cu cm. The factor of 3 difference in the mean densities between the two populations implies differences in the orbital evolution time scales.

Timelike naked singularity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goswami, Rituparno; Joshi, Pankaj S.; Vaz, Cenalo

We construct a class of spherically symmetric collapse models in which a naked singularity may develop as the end state of collapse. The matter distribution considered has negative radial and tangential pressures, but the weak energy condition is obeyed throughout. The singularity forms at the center of the collapsing cloud and continues to be visible for a finite time. The duration of visibility depends on the nature of energy distribution. Hence the causal structure of the resulting singularity depends on the nature of the mass function chosen for the cloud. We present a general model in which the naked singularitymore » formed is timelike, neither pointlike nor null. Our work represents a step toward clarifying the necessary conditions for the validity of the Cosmic Censorship Conjecture.« less

Lack of host specificity of copepod crustaceans associated with mushroom corals in the Red Sea.

PubMed

Ivanenko, Viatcheslav N; Hoeksema, Bert W; Mudrova, Sofya V; Nikitin, Mikhail A; Martínez, Alejandro; Rimskaya-Korsakova, Nadezda N; Berumen, Michael L; Fontaneto, Diego

2018-06-14

The radiation of symbiotic copepods (Crustacea: Copepoda) living in association with stony corals (Cnidaria: Scleractinia) is considered host-specific and linked to the phylogenetic diversification of their hosts. However, symbiotic copepods are poorly investigated, occurrence records are mostly anecdotal, and no explicit analysis exists regarding their relationship with the hosts. Here, we analysed the occurrence of symbiotic copepods on different co-occurring and phylogenetically closely related scleractinian corals. We used an innovative approach of DNA extraction from single microscopic specimens that preserves the shape of the organisms for integrative morphological studies. The rationale of the study involved: (i) sampling of mushroom corals (Fungiidae) belonging to 13 species and eight genera on different reefs along the Saudi coastline in the Red Sea, (ii) extraction of all the associated copepods, (iii) morphological screening and identification of copepod species, (iv) use of DNA taxonomy on mitochondrial and nuclear markers to determine species boundaries for morphologically unknown copepod species, (v) reconstruction of phylogenies to understand their evolutionary relationships, and (vi) analysis of the ecological drivers of the occurrence, diversity and host specificity of the copepods. The seven species of coral-associated copepods, all new to science, did not show any statistically significant evidence of host-specificity or other pattern of ecological association. We thus suggest that, contrary to most assumptions and previous anecdotal evidence on this coral-copepod host-symbiont system, the association between copepods and their host corals is rather labile, not strict, and not phylogenetically constrained, changing our perception on evolutionary patterns and processes in symbiotic copepods. Copyright © 2018. Published by Elsevier Inc.

An evaluation of coral lophelia pertusa mucus as an analytical matrix for environmental monitoring: A preliminary proteomic study.

PubMed

Provan, Fiona; Nilsen, Mari Mæland; Larssen, Eivind; Uleberg, Kai-Erik; Sydnes, Magne O; Lyng, Emily; Øysæd, Kjell Birger; Baussant, Thierry

2016-01-01

For the environmental monitoring of coral, mucus appears to be an appropriate biological matrix due to its array of functions in coral biology and the non-intrusive manner in which it can be collected. The aim of the present study was to evaluate the feasibility of using mucus of the stony coral Lophelia pertusa (L. pertusa) as an analytical matrix for discovery of biomarkers used for environmental monitoring. More specifically, to assess whether a mass-spectrometry-based proteomic approach can be applied to characterize the protein composition of coral mucus and changes related to petroleum discharges at the seafloor. Surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS) screening analyses of orange and white L. pertusa showed that the mucosal protein composition varies significantly with color phenotype, a pattern not reported prior to this study. Hence, to reduce variability from phenotype difference, L. pertusa white individuals only were selected to characterize in more detail the basal protein composition in mucus using liquid chromatography, mass spectrometry, mass spectrometry (LC-MS/MS). In total, 297 proteins were identified in L. pertusa mucus of unexposed coral individuals. Individuals exposed to drill cuttings in the range 2 to 12 mg/L showed modifications in coral mucus protein composition compared to unexposed corals. Although the results were somewhat inconsistent between individuals and require further validation in both the lab and the field, this study demonstrated preliminary encouraging results for discovery of protein markers in coral mucus that might provide more comprehensive insight into potential consequences attributed to anthropogenic stressors and may be used in future monitoring of coral health.

Can accretion disk properties observationally distinguish black holes from naked singularities?

NASA Astrophysics Data System (ADS)

Kovács, Z.; Harko, T.

2010-12-01

Naked singularities are hypothetical astrophysical objects, characterized by a gravitational singularity without an event horizon. Penrose has proposed a conjecture, according to which there exists a cosmic censor who forbids the occurrence of naked singularities. Distinguishing between astrophysical black holes and naked singularities is a major challenge for present day observational astronomy. In the context of stationary and axially symmetrical geometries, a possibility of differentiating naked singularities from black holes is through the comparative study of thin accretion disks properties around rotating naked singularities and Kerr-type black holes, respectively. In the present paper, we consider accretion disks around axially-symmetric rotating naked singularities, obtained as solutions of the field equations in the Einstein-massless scalar field theory. A first major difference between rotating naked singularities and Kerr black holes is in the frame dragging effect, the angular velocity of a rotating naked singularity being inversely proportional to its spin parameter. Because of the differences in the exterior geometry, the thermodynamic and electromagnetic properties of the disks (energy flux, temperature distribution and equilibrium radiation spectrum) are different for these two classes of compact objects, consequently giving clear observational signatures that could discriminate between black holes and naked singularities. For specific values of the spin parameter and of the scalar charge, the energy flux from the disk around a rotating naked singularity can exceed by several orders of magnitude the flux from the disk of a Kerr black hole. In addition to this, it is also shown that the conversion efficiency of the accreting mass into radiation by rotating naked singularities is always higher than the conversion efficiency for black holes, i.e., naked singularities provide a much more efficient mechanism for converting mass into radiation than black

Association of coral algal symbionts with a diverse viral community responsive to heat shock.

PubMed

Brüwer, Jan D; Agrawal, Shobhit; Liew, Yi Jin; Aranda, Manuel; Voolstra, Christian R

2017-08-17

Stony corals provide the structural foundation of coral reef ecosystems and are termed holobionts given they engage in symbioses, in particular with photosynthetic dinoflagellates of the genus Symbiodinium. Besides Symbiodinium, corals also engage with bacteria affecting metabolism, immunity, and resilience of the coral holobiont, but the role of associated viruses is largely unknown. In this regard, the increase of studies using RNA sequencing (RNA-Seq) to assess gene expression provides an opportunity to elucidate viral signatures encompassed within the data via careful delineation of sequence reads and their source of origin. Here, we re-analyzed an RNA-Seq dataset from a cultured coral symbiont (Symbiodinium microadriaticum, Clade A1) across four experimental treatments (control, cold shock, heat shock, dark shock) to characterize associated viral diversity, abundance, and gene expression. Our approach comprised the filtering and removal of host sequence reads, subsequent phylogenetic assignment of sequence reads of putative viral origin, and the assembly and analysis of differentially expressed viral genes. About 15.46% (123 million) of all sequence reads were non-host-related, of which <1% could be classified as archaea, bacteria, or virus. Of these, 18.78% were annotated as virus and comprised a diverse community consistent across experimental treatments. Further, non-host related sequence reads assembled into 56,064 contigs, including 4856 contigs of putative viral origin that featured 43 differentially expressed genes during heat shock. The differentially expressed genes included viral kinases, ubiquitin, and ankyrin repeat proteins (amongst others), which are suggested to help the virus proliferate and inhibit the algal host's antiviral response. Our results suggest that a diverse viral community is associated with coral algal endosymbionts of the genus Symbiodinium, which prompts further research on their ecological role in coral health and resilience.

Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds

PubMed Central

Zhang, Zhenming; Zhou, Yunchao; Wang, Shijie

2018-01-01

Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS) technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m) were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km2, 4.50 km2, and 1.87 km2, respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content. PMID:29652811

Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds.

PubMed

Zhang, Zhenming; Zhou, Yunchao; Wang, Shijie; Huang, Xianfei

2018-04-13

Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS) technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m) were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km², 4.50 km², and 1.87 km², respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content.

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

NASA Astrophysics Data System (ADS)

Fabricius, K. E.

1997-07-01

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

Naked singularities in higher dimensional Vaidya space-times

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, S. G.; Dadhich, Naresh

We investigate the end state of the gravitational collapse of a null fluid in higher-dimensional space-times. Both naked singularities and black holes are shown to be developing as the final outcome of the collapse. The naked singularity spectrum in a collapsing Vaidya region (4D) gets covered with the increase in dimensions and hence higher dimensions favor a black hole in comparison to a naked singularity. The cosmic censorship conjecture will be fully respected for a space of infinite dimension.

Just Add Water and Stir. Graduate Chemistry Laboratory, Stony Brook

ERIC Educational Resources Information Center

Yee, Roger

1974-01-01

Using traditional building materials and a fast-track recipe, the architects, acting as construction manager, completed the Graduate Chemistry Laboratory at Stony Brook, New York, two full years ahead of schedule. (Author/MF)

76 FR 20957 - Gulf of Mexico Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-14

... Mexico Fishery Management Council's Red Drum, Reef Fish, Shrimp, Coral and Coral Reefs, and Stony Crab... Mexico Fishery Management Council's Red Drum, Reef Fish, Shrimp, Coral and Coral Reefs, and Stone Crab... to protect threatened staghorn and elkhorn corals, and requirements for gear marking of all spiny...

Determining the Extent and Characterizing Coral Reef Habitats of the Northern Latitudes of the Florida Reef Tract (Martin County)

PubMed Central

Walker, Brian K.; Gilliam, David S.

2013-01-01

Climate change has recently been implicated in poleward shifts of many tropical species including corals; thus attention focused on higher-latitude coral communities is warranted to investigate possible range expansions and ecosystem shifts due to global warming. As the northern extension of the Florida Reef Tract (FRT), the third-largest barrier reef ecosystem in the world, southeast Florida (25–27° N latitude) is a prime region to study such effects. Most of the shallow-water FRT benthic habitats have been mapped, however minimal data and limited knowledge exist about the coral reef communities of its northernmost reaches off Martin County. First benthic habitat mapping was conducted using newly acquired high resolution LIDAR bathymetry and aerial photography where possible to map the spatial extent of coral reef habitats. Quantitative data were collected to characterize benthic cover and stony coral demographics and a comprehensive accuracy assessment was performed. The data were then analyzed in a habitat biogeography context to determine if a new coral reef ecosystem region designation was warranted. Of the 374 km2 seafloor mapped, 95.2% was Sand, 4.1% was Coral Reef and Colonized Pavement, and 0.7% was Other Delineations. Map accuracy assessment yielded an overall accuracy of 94.9% once adjusted for known map marginal proportions. Cluster analysis of cross-shelf habitat type and widths indicated that the benthic habitats were different than those further south and warranted designation of a new coral reef ecosystem region. Unlike the FRT further south, coral communities were dominated by cold-water tolerant species and LIDAR morphology indicated no evidence of historic reef growth during warmer climates. Present-day hydrographic conditions may be inhibiting poleward expansion of coral communities along Florida. This study provides new information on the benthic community composition of the northern FRT, serving as a baseline for future community shift and

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

PubMed

Walker, Brian K; Gilliam, David S

2013-01-01

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

Interactive effects of oxygen, carbon dioxide and flow on photosynthesis and respiration in the scleractinian coral Galaxea fascicularis.

PubMed

Osinga, Ronald; Derksen-Hooijberg, Marlous; Wijgerde, Tim; Verreth, Johan A J

2017-06-15

Rates of dark respiration and net photosynthesis were measured for six replicate clonal fragments of the stony coral Galaxea fascicularis (Linnaeus 1767), which were incubated under 12 different combinations of dissolved oxygen (20%, 100% and 150% saturation), dissolved carbon dioxide (9.5 and 19.1 µmol l -1 ) and water flow (1-1.6 versus 4-13 cm s -1 ) in a repeated measures design. Dark respiration was enhanced by increased flow and increased oxygen saturation in an interactive way, which relates to improved oxygen influx into the coral tissue. Oxygen saturation did not influence net photosynthesis: neither hypoxia nor hyperoxia affected net photosynthesis, irrespective of flow and pH, which suggests that hyperoxia does not induce high rates of photorespiration in this coral. Flow and pH had a synergistic effect on net photosynthesis: at high flow, a decrease in pH stimulated net photosynthesis by 14%. These results indicate that for this individual of G. fascicularis , increased uptake of carbon dioxide rather than increased efflux of oxygen explains the beneficial effect of water flow on photosynthesis. Rates of net photosynthesis measured in this study are among the highest ever recorded for scleractinian corals and confirm a strong scope for growth. © 2017. Published by The Company of Biologists Ltd.

A Possible Role for Vitamin C in Coral Calcification

NASA Astrophysics Data System (ADS)

Rosenthal, J. J.; Roberson, L.; Vazquez, N.

2016-02-01

Despite the importance of coral reefs to tropical, marine ecosystems, the biological components of the calcification process are poorly understood. Because calcification must involve the delivery of organic and inorganic components across cell membranes, we postulate that it has similar features to epithelial and neuronal transport mechanisms in vertebrates. Accordingly, we are interested in identifying the specific membrane transporters underlying skeleton formation. As a model, we are using larvae from the ubiquitous Caribbean species Porites astreoides, a rapidly growing stony coral that is resistant to anthropogenic stressors. Using Illumina RNAseq, we assembled a larval transcriptome and compared gene expression between swimming larvae and recently settled ones that had just commenced the process of calcification. As expected, we identified many ion transporter, pump and channel transcripts that were upregulated in settled larvae. It was surprising, however, to find that the most upregulated transcript appeared to encode a Na-dependent Vitamin C transporter (SLC23A). In vertebrates, SLC23A transporters play a vital role in bone morphogenesis where Vitamin C is an essential cofactor for enzymes that condition collagen precursors for assembly into mature molecules. In corals, collagen has been identified as a component of the skeleton's extracellular matrix. Using in situ hybridization, we showed that the P. astreoides SLC23A messages were expressed in regions adjacent to rapid skeleton formation, on the aboral surface and septa of settled larvae. To confirm that the coral clone is indeed a Vitamin C transporter, we expressed it in Xenopus oocytes and studied its activity using voltage-clamp. Preliminary data demonstrate that it induces a current that is activated by Na and Vitamin C. This approach will help us better understand the molecular mechanisms underlying calcification and how they might respond to environmental change.

Fluid inclusions in stony meteorites

NASA Technical Reports Server (NTRS)

Warner, J. L.; Ashwal, L. D.; Bergman, S. C.; Gibson, E. K., Jr.; Henry, D. J.; Lee-Berman, R.; Roedder, E.; Belkin, H. E.

1983-01-01

The fluid inclusions presently described for five stony meteorites brings to seven the number of such meteorites confirmed. Homogenization temperatures are reproducible in each inclusion, and range from 25 C to over 225 C, with some vapor plus liquid inclusions remaining at 225 C, the highest temperature in these microthermometric experiments. Upon cooling, the fluid in some inclusions appears to freeze, as indicated by deformation and immobilization of the vapor bubble at low temperatures. Melting temperatures are by contrast difficult to observe and are not reproducible. Microthermometric data for the fluid in diogenite ALPHA 77256 and inclusions in four chondrites suggest that the fluid is aqueous, with a high solute content.

Dual recognition activity of a rhamnose-binding lectin to pathogenic bacteria and zooxanthellae in stony coral Pocillopora damicornis.

PubMed

Zhou, Zhi; Yu, Xiaopeng; Tang, Jia; Zhu, Yunjie; Chen, Guangmei; Guo, Liping; Huang, Bo

2017-05-01

Rhamnose-binding lectin (RBL) is a type of Ca 2+ -independent lectin with tandem repeat carbohydrate-recognition domain, and is crucial for the innate immunity in many invertebrates. In this study, the cDNA sequence encoding RBL in coral Pocillopora damicornis (PdRBL-1) was cloned. The PdRBL-1 protein shared highest amino acid sequence similarity (55%) with the polyp of Hydra vulgaris, and contained a signal peptide and two tandem carbohydrate-recognition domains in which all cysteine residues were conserved. Surface plasmon resonance method revealed that the recombinant PdRBL-1 protein bound to LPS and Lipid A, but not to LTA, β-glucan, mannose and Poly (I:C). Results also showed that it bonded with zooxanthellae using western blotting method, and that the bound protein was detectable only at concentrations higher than 10 2 zooxanthellae cell mL -1 . When recombinant PdRBL-1 protein was preincubated with LPS, lower amounts of protein bound to zooxanthellae compared to cells not preincubated with LPS. Furthermore, PdRBL-1 mRNA expression increased significantly at 12 h, and declined to the baseline at 24 h after heat stress at 31 °C. These results collectively suggest that PdRBL-1 could recognize not only pathogenic bacteria but also symbiotic zooxanthellae, and that the recognition of zooxanthellae by PdRBL-1 could be repressed by pathogenic bacteria through competitive binding. This information allows us to gain new insights in the mechanisms influencing the establishment and maintenance of coral-zooxanthella symbiosis in coral P. damicornis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Most stony meteorites come from the asteroid belt

NASA Technical Reports Server (NTRS)

Anders, E.

1978-01-01

The presence of trapped solar gas in stony meteorites places their origin in the regoliths of asteroidal-type bodies. The most plausible sources are the C (carbonaceous) and S (siliceous) asteroids, in spite of the differences between the spectra of S asteroids and ordinary chondrites. This problem is a central one for the interpretation of both astronomical observations and dynamical theory.

Particle creation by naked singularities in higher dimensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyamoto, Umpei; Nemoto, Hiroya; Shimano, Masahiro

Recently, the possibility was pointed out by one of the present authors and his collaborators that an effective naked singularity referred to as ''a visible border of spacetime'' is generated by high-energy particle collision in the context of large extra dimensions or TeV-scale gravity. In this paper, we investigate the particle creation by a naked singularity in general dimensions, while adopting a model in which a marginally naked singularity forms in the collapse of a homothetic lightlike pressureless fluid. We find that the spectrum deviates from that of Hawking radiation due to scattering near the singularity but can be recastmore » in quasithermal form. The temperature is always higher than that of Hawking radiation of a same-mass black hole, and can be arbitrarily high depending on a parameter in the model. This implies that, in principle, the naked singularity may be distinguished from a black hole in collider experiments.« less

Seasonal Variability in Calorimetric Energy Content of Two Caribbean Mesophotic Corals

PubMed Central

Brandtneris, Viktor W.; Brandt, Marilyn E.; Glynn, Peter W.; Gyory, Joanna; Smith, Tyler B.

2016-01-01

Energetic responses of zooxanthellate reef corals along depth gradients have relevance to the refugia potential of mesophotic coral ecosystems (MCEs). Previous observations suggested that MCEs in the Caribbean are thermally buffered during the warmest parts of the year and occur within or just below the chlorophyll maximum, suggesting abundant trophic resources. However, it is not known if mesophotic corals can maintain constant energy needs throughout the year with changing environmental and biological conditions. The energetic content of tissues from the stony coral species Orbicella faveolata and Agaricia lamarcki was measured on the southern insular shelf of St. Thomas, US Virgin Islands (USVI), using micro-bomb calorimetry. Three sites for each species, at depths of 6m, 25m, 38m and 63m, were selected to capture energetic differences across the major vertical range extent of both species in the USVI—and sampled over five periods from April 2013 to April 2014. Mesophotic colonies of O. faveolata exhibited a significant reduction in energetic content during the month of September 2013 compared to mid-depth and shallow colonies (p = 0.032), whereas A. lamarcki experienced similar energetic variability, but with a significant reduction in energy content that occurred in July 2013 for colonies at sites deeper than 25m (p = 0.014). The results of calorimetric analyses indicate that O. faveolata may be at risk during late summer stress events, possibly due to the timing of reproductive activities. The low-point of A. lamarcki energy content, which may also coincide with reproduction, occurs prior to seasonal stress events, indicating contrasting, species-specific responses to environmental variability on MCEs. PMID:27050430

Re-evaluating the health of coral reef communities: baselines and evidence for human impacts across the central Pacific.

PubMed

Smith, Jennifer E; Brainard, Rusty; Carter, Amanda; Grillo, Saray; Edwards, Clinton; Harris, Jill; Lewis, Levi; Obura, David; Rohwer, Forest; Sala, Enric; Vroom, Peter S; Sandin, Stuart

2016-01-13

Numerous studies have documented declines in the abundance of reef-building corals over the last several decades and in some but not all cases, phase shifts to dominance by macroalgae have occurred. These assessments, however, often ignore the remainder of the benthos and thus provide limited information on the present-day structure and function of coral reef communities. Here, using an unprecedentedly large dataset collected within the last 10 years across 56 islands spanning five archipelagos in the central Pacific, we examine how benthic reef communities differ in the presence and absence of human populations. Using islands as replicates, we examine whether benthic community structure is associated with human habitation within and among archipelagos and across latitude. While there was no evidence for coral to macroalgal phase shifts across our dataset we did find that the majority of reefs on inhabited islands were dominated by fleshy non-reef-building organisms (turf algae, fleshy macroalgae and non-calcifying invertebrates). By contrast, benthic communities from uninhabited islands were more variable but in general supported more calcifiers and active reef builders (stony corals and crustose coralline algae). Our results suggest that cumulative human impacts across the central Pacific may be causing a reduction in the abundance of reef builders resulting in island scale phase shifts to dominance by fleshy organisms. © 2016 The Author(s).

Preservation at Stony Brook. Preservation Planning Program. Study Report.

ERIC Educational Resources Information Center

Cook, Donald C.; And Others

This final report is a product of a Preservation Planning Program (PPP) self-study conducted by the State University of New York (SUNY), Stony Brook, working with the Association of Research Libraries' (ARL) Office of Management Studies (OMS). The PPP is designed to put self-help tools into the hands of library staff responsible for developing…

Immunolocalization of skeletal matrix proteins in tissue and mineral of the coral Stylophora pistillata

PubMed Central

Mass, Tali; Drake, Jeana L.; Peters, Esther C.; Jiang, Wenge; Falkowski, Paul G.

2014-01-01

The precipitation and assembly of calcium carbonate skeletons by stony corals is a precisely controlled process regulated by the secretion of an ECM. Recently, it has been reported that the proteome of the skeletal organic matrix (SOM) contains a group of coral acid-rich proteins as well as an assemblage of adhesion and structural proteins, which together, create a framework for the precipitation of aragonite. To date, we are aware of no report that has investigated the localization of individual SOM proteins in the skeleton. In particular, no data are available on the ultrastructural mapping of these proteins in the calcification site or the skeleton. This information is crucial to assessing the role of these proteins in biomineralization. Immunological techniques represent a valuable approach to localize a single component within a calcified skeleton. By using immunogold labeling and immunohistochemical assays, here we show the spatial arrangement of key matrix proteins in tissue and skeleton of the common zooxanthellate coral, Stylophora pistillata. To our knowledge, our results reveal for the first time that, at the nanoscale, skeletal proteins are embedded within the aragonite crystals in a highly ordered arrangement consistent with a diel calcification pattern. In the tissue, these proteins are not restricted to the calcifying epithelium, suggesting that they also play other roles in the coral’s metabolic pathways. PMID:25139990

A survey of cellular reactions to environmental stress and disease in Caribbean scleractinian corals

NASA Astrophysics Data System (ADS)

Peters, Esther C.

1984-03-01

Despite growing concern about the demise of coral reefs in many areas of the world, few studies have investigated the possibility that bacteria- or virus-caused diseases may be important agents in the disappearance of living coral tissue from reefs, and that their occurrence and transmission may be influenced by natural or man-made changes in water quality, particularly increased sedimentation and turbidity. One forereef site off St. Croix, U. S. Virgin Islands, and three shallow-water reef sites off Puerto Rico were examined for variations in coral composition, local environmental conditions, and the presence of possible diseases in the stony corals. Visual observations were supplemented with standard histopathological examination under the light microscope of tissues from 257 specimens (representing 9 genera and 13 species), along with additional samples obtained from the Netherlands Antilles, the Grenadines, the Florida Keys and the Smithsonian Coral Reef Microcosm. This procedure proved to be necessary to accurately determine the condition of the colony, to detect the presence of microorganisms, and to correlate tissue health and microparasite infestations with apparent symptoms. These lesions varied with the species and the site. For example, off Guayanilla Bay, three species showed increased or decreased mucosecretory cell development, and another exhibited an unusual microparasite, which may be related to the chronic sedimentation at this site. Although colonies of several species showed signs of “white band disease” at five locations, bacterial colonies composed of Gram-negative rods were present only in acroporid tissues from the relatively pristine St. Croix site and the Netherlands Antilles. The distribution and possible mode of occurrence of these and other diseases and microparasite infestations suggest that acute changes in microhabitat conditions or injuries to individual colonies may be as important to the development of some of these lesions as

Perfect fluid tori orbiting Kehagias-Sfetsos naked singularities

NASA Astrophysics Data System (ADS)

Stuchlík, Z.; Pugliese, D.; Schee, J.; Kučáková, H.

2015-09-01

We construct perfect fluid tori in the field of the Kehagias-Sfetsos (K-S) naked singularities. These are spherically symmetric vacuum solutions of the modified Hořava quantum gravity, characterized by a dimensionless parameter ω M^2, combining the gravitational mass parameter M of the spacetime with the Hořava parameter ω reflecting the role of the quantum corrections. In dependence on the value of ω M^2, the K-S naked singularities demonstrate a variety of qualitatively different behavior of their circular geodesics that is fully reflected in the properties of the toroidal structures, demonstrating clear distinction to the properties of the torii in the Schwarzschild spacetimes. In all of the K-S naked singularity spacetimes the tori are located above an "antigravity" sphere where matter can stay in a stable equilibrium position, which is relevant for the stability of the orbiting fluid toroidal accretion structures. The signature of the K-S naked singularity is given by the properties of marginally stable tori orbiting with the uniform distribution of the specific angular momentum of the fluid, l= const. In the K-S naked singularity spacetimes with ω M^2 > 0.2811, doubled tori with the same l= const can exist; mass transfer between the outer torus and the inner one is possible under appropriate conditions, while only outflow to the outer space is allowed in complementary conditions. In the K-S spacetimes with ω M^2 < 0.2811, accretion from cusped perfect fluid tori is not possible due to the non-existence of unstable circular geodesics.

'Naked' radiopharmaceuticals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallner, Paul E.

The term 'naked' radiopharmaceuticals, more appropriately, 'unbound' radiopharmaceuticals, refers to any radioisotope used for clinical research or clinical purposes that is not attached to a chemical or biological carrier, and that localizes in various tissues because of a physiologic or chemical propensity/affinity, or secondary to focal anatomic placement. Although they remain useful in selected clinical circumstances, the available agents (except for Iodine-131) have been relegated to an unfortunate and somewhat secondary role. The agents remain useful and worthy of consideration for new clinical investigation and clinical use.

Periastron shift for a spinning test particle around naked singularities

NASA Astrophysics Data System (ADS)

Mukherjee, Sajal

2018-06-01

In the present article, we investigate the Periastron precession for a spinning test particle moving in nearly circular orbits around naked singularities. We consider two well-known solutions that can produce a spacetime with naked singularity—(a) first, the Reissner-Nordström metric, which is a static charged solution with spherical symmetry, and (b) second, the stationary, axisymmetric Kerr metric. For simplicity, we only consider the motion confined on the equatorial plane in both these cases and solve exactly the Mathisson-Papapetrou equations. In addition, we analytically compute the Periastron precession within the framework of linear spin approximation. The inclusion of the spin parameter modifies the results with nonspinning particles and also reflects some interesting properties of the naked geometries. Furthermore, we carried out a numerical approach without any assumptions to probe the large order spin values. The implication of the spin-curvature coupling in connection with the naked geometries is also discussed.

The Stony Brook/SMARTS Atlas of (mostly) Southern Novae

NASA Astrophysics Data System (ADS)

Walter, F. M.

2014-12-01

The Stony Brook/SMARTS Atlas of (mostly) Southern Novae is an on-line compendium of data on 69 novae, mostly in the southern hemisphere, observed since 2003 April. The data consist of low resolution spectra (400< R <4000) and optical and near-IR photometry obtained with the SMARTS telescopes. I shall describe the atlas and the data, and then present some examples of the data analyzes being undertaken with this synoptic data set.

Extreme mitochondrial variation in the Atlantic gall crab Opecarcinus hypostegus (Decapoda: Cryptochiridae) reveals adaptive genetic divergence over Agaricia coral hosts

PubMed Central

van Tienderen, Kaj M.; van der Meij, Sancia E. T.

2017-01-01

The effectiveness of migration in marine species exhibiting a pelagic larval stage is determined by various factors, such as ocean currents, pelagic larval stage duration and active habitat selection. Direct measurement of larval movements is difficult and, consequently, factors determining the gene flow patterns remain poorly understood for many species. Patterns of gene flow play a key role in maintaining genetic homogeneity in a species by dampening the effects of local adaptation. Coral-dwelling gall crabs (Cryptochiridae) are obligate symbionts of stony corals (Scleractinia). Preliminary data showed high genetic diversity on the COI gene for 19 Opecarcinus hypostegus specimens collected off Curaçao. In this study, an additional 176 specimens were sequenced and used to characterize the population structure along the leeward side of Curaçao. Extremely high COI genetic variation was observed, with 146 polymorphic sites and 187 unique haplotypes. To determine the cause of this high genetic diversity, various gene flow scenarios (geographical distance along the coast, genetic partitioning over depth, and genetic differentiation by coral host) were examined. Adaptive genetic divergence across Agariciidae host species is suggested to be the main cause for the observed high intra-specific variance, hypothesised as early signs of speciation in O. hypostegus. PMID:28079106

Stony Brook's Graduate Courses in Clear, Vivid, Conversational Communication

NASA Astrophysics Data System (ADS)

Bass, E.

2011-12-01

Graduate students in the sciences at Stony Brook University are taking for-credit courses to learn to communicate more effectively about science with people outside their disciplines, including public officials, the press, students, potential funders and employers, colleagues in other fields, and the general public. Five Communicating Science courses are offered; two more will be added in January, 2012. The courses are offered by the School of Journalism and developed by the Center for Communicating Science (CCS). This interdisciplinary center was founded in 2009, with the participation of Alan Alda, the actor, writer, director and longtime advocate for science, who is a Visiting Professor at Stony Brook. At the core of the program are three 1-credit (14-hour) modules that rely on experiential learning, repeated practice and immediate, interactive feedback. In Distilling Your Message, students practice speaking clearly, vividly and conversationally about their work at different levels of complexity and formality to different audiences, using storytelling techniques where appropriate. In Writing for the Public, they extend these skills into writing. In Improvisation for Scientists, the most unconventional of the courses, students play improvisational theater games to help themselves connect more directly, personally and responsively with their audiences. In their first two semesters, the courses are expected to serve about 90 students, taking a total of about 180 credits. Most of the courses have filled quickly, mixing master's and doctoral students from more than a dozen fields, including marine and atmospheric sciences. Three to six credits of Communicating Science courses are required for students in two programs, an MA in Marine Conservation and Policy and an Advanced Certificate in Health Communications. The content and methods of the courses are based largely on lessons learned from evaluations of all-day workshops that CCS has conducted for more than 250

Cosmic Ray Exposure Ages of Stony Meteorites: Space Erosion or Yarkovsky?

NASA Technical Reports Server (NTRS)

Rubincam, David Parry

2014-01-01

Space erosion from dust impacts may set upper limits on the cosmic ray exposure (CRE) ages of stony meteorites. A meteoroid orbiting within the asteroid belt is bombarded by both cosmic rays and interplanetary dust particles. Galactic cosmic rays penetrate only the first few meters of the meteoroid; deeper regions are shielded. The dust particle impacts create tiny craters on the meteoroid's surface, wearing it away by space erosion (abrasion) at a particular rate. Hence a particular point inside a meteoroid accumulates cosmic ray products only until that point wears away, limiting CRE ages. The results would apply to other regolith-free surfaces in the solar system as well, so that abrasion may set upper CRE age limits which depend on the dusty environment. Calculations based on N. Divine's dust populations and on micrometeoroid cratering indicate that stony meteoroids in circular ecliptic orbits at 2 AU will record 21Ne CRE ages of approx.176 x 10(exp 6) years if dust masses are in the range 10(exp -21) - 10(exp -3) kg. This is in broad agreement with the maximum observed CRE ages of approx. 100 x 10(exp 6) years for stones. High erosion rates in the inner solar system may limit the CRE ages of Near-Earth Asteroids (NEAs) to approx. 120 x 10(exp 6) years. If abrasion should prove to be approx. 6 times quicker than found here, then space erosion may be responsible for many of the measured CRE ages of main belt stony meteorites. In that case the CRE ages may not measure the drift time to the resonances due to the Yarkovsky effects as in the standard scenario, and that for some reason Yarkovsky is ineffective.

Composition and biological activities of the aqueous extracts of three scleractinian corals from the Mexican Caribbean: Pseudodiploria strigosa, Porites astreoides and Siderastrea siderea.

PubMed

García-Arredondo, Alejandro; Rojas-Molina, Alejandra; Ibarra-Alvarado, César; Lazcano-Pérez, Fernando; Arreguín-Espinosa, Roberto; Sánchez-Rodríguez, Judith

2016-01-01

Scleractinian corals (stony corals) are the most abundant reef-forming cnidarians found in coral reefs throughout the world. Despite their abundance and ecological importance, information about the diversity of their toxins and their biological activities is very scarce. In this study, the chemical composition and the biological activities of the aqueous extracts of Pseudodiploria strigosa , Porites astreoides and Siderastrea siderea , three scleractinian corals from the Mexican Caribbean, have been assessed for the first time. Toxicity of the extracts was assessed in crickets; the presence of cytolysins was detected by the hemolysis assay; the vasoconstrictor activity was determined by the isolated rat aortic ring assay; the nociceptive activity was evaluated by the formalin test. The presence of phospholipases A 2 (PLA 2 ), serine proteases, and hyaluronidases was determined by enzymatic methods. Low-molecular-weight fractions were obtained by gel filtration chromatography and ultrafiltration. Extracts from the three species were toxic to crickets, induced hemolysis in human and rat erythrocytes, produced vasoconstriction on isolated rat aortic rings, and presented phospholipase A 2 and serine-protease activity. Despite the fact that these corals are not considered to be harmless to humans, the extracts generated significant nociceptive responses. The matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of the low-molecular-weight fractions revealed the presence of peptides within a mass range of 3000 to 6000 Da. These fractions were toxic to crickets and two of them induced a transitory vasoconstrictor effect on isolated rat aortic rings. This study suggests that scleractinian corals produce low-molecular-weight peptides that are lethal to crickets and induce vasoconstriction.

The 1908 Tunguska explosion - Atmospheric disruption of a stony asteroid

NASA Technical Reports Server (NTRS)

Chyba, Christofer F.; Thomas, Paul J.; Zahnle, Kevin J.

1993-01-01

The explosion over Tunguska, Central Siberia, in 1908 released 10 to 20 megatons (high explosive equivalent) of energy at an altitude of about 10 km. This event represents a typical fate for stony asteroids tens of meters in radius entering the Earth's atmosphere at common hypersonic velocities. Comets and carbonaceous asteroids of the appropriate energy disrupt too high, whereas typical iron objects reach and crater the terrestrial surface.

Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Virbhadra, K. S.; Keeton, C. R.; Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854

We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for Schwarzschild black holes, weakly naked, and marginally strongly naked singularities. However, the lensing characteristics of strongly naked singularities are qualitatively very different from those due to Schwarzschild black holes. The images produced by Schwarzschild black hole lenses and weakly naked and marginallymore » strongly naked singularity lenses always have positive time delays. On the other hand, strongly naked singularity lenses can give rise to images with positive, zero, or negative time delays. In particular, for a large angular source position the direct image (the outermost image on the same side as the source) due to strongly naked singularity lensing always has a negative time delay. We also found that the scalar field decreases the time delay and increases the total magnification of images; this result could have important implications for cosmology. As the Janis-Newman-Winicour metric also describes the exterior gravitational field of a scalar star, naked singularities as well as scalar star lenses, if these exist in nature, will serve as more efficient cosmic telescopes than regular gravitational lenses.« less

Species delimitation of common reef corals in the genus Pocillopora using nucleotide sequence phylogenies, population genetics and symbiosis ecology.

PubMed

Pinzón, Jorge H; LaJeunesse, Todd C

2011-01-01

Stony corals in the genus Pocillopora are among the most common and widely distributed of Indo-Pacific corals and, as such, are often the subject of physiological and ecological research. In the far Tropical Eastern Pacific (TEP), they are major constituents of shallow coral communities, exhibiting considerable variability in colony shape and branch morphology and marked differences in response to thermal stress. Numerous intermediates occur between morphospecies that may relate to extensive hybridization. The diversity of the Pocillopora genus in the TEP was analysed genetically using nuclear ribosomal (ITS2) and mitochondrial (ORF) sequences, and population genetic markers (seven microsatellite loci). The resident dinoflagellate endosymbiont (Symbiodinium sp.) in each sample was also characterized using sequences of the internal transcribed spacer 2 (ITS2) rDNA and the noncoding region of the chloroplast psbA minicircle. From these analyses, three symbiotically distinct, reproductively isolated, nonhybridizing, evolutionarily divergent animal lineages were identified. Designated types 1, 2 and 3, these groupings were incongruent with traditional morphospecies classification. Type 1 was abundant and widespread throughout the TEP; type 2 was restricted to the Clipperton Atoll; and type 3 was found only in Panama and the Galapagos Islands. Each type harboured a different Symbiodinium'species lineage' in Clade C, and only type 1 associated with the 'stress-tolerant'Symbiodinium glynni (D1). The accurate delineation of species and implementation of a proper taxonomy may profoundly improve our assessment of Pocillopora's reproductive biology, biogeographic distributions, and resilience to climate warming, information that must be considered when planning for the conservation of reef corals. © 2010 Blackwell Publishing Ltd.

Virtually Naked: Virtual Environment Reveals Sex-Dependent Nature of Skin Disclosure

PubMed Central

Lomanowska, Anna M.; Guitton, Matthieu J.

2012-01-01

The human tendency to reveal or cover naked skin reflects a competition between the individual propensity for social interactions related to sexual appeal and interpersonal touch versus climatic, environmental, physical, and cultural constraints. However, due to the ubiquitous nature of these constraints, isolating on a large scale the spontaneous human tendency to reveal naked skin has remained impossible. Using the online 3-dimensional virtual world of Second Life, we examined spontaneous human skin-covering behavior unhindered by real-world climatic, environmental, and physical variables. Analysis of hundreds of avatars revealed that virtual females disclose substantially more naked skin than virtual males. This phenomenon was not related to avatar hypersexualization as evaluated by measurement of sexually dimorphic body proportions. Furthermore, analysis of skin-covering behavior of a population of culturally homogeneous avatars indicated that the propensity of female avatars to reveal naked skin persisted despite explicit cultural norms promoting less revealing attire. These findings have implications for further understanding how sex-specific aspects of skin disclosure influence human social interactions in both virtual and real settings. PMID:23300580

Virtually naked: virtual environment reveals sex-dependent nature of skin disclosure.

PubMed

Lomanowska, Anna M; Guitton, Matthieu J

2012-01-01

The human tendency to reveal or cover naked skin reflects a competition between the individual propensity for social interactions related to sexual appeal and interpersonal touch versus climatic, environmental, physical, and cultural constraints. However, due to the ubiquitous nature of these constraints, isolating on a large scale the spontaneous human tendency to reveal naked skin has remained impossible. Using the online 3-dimensional virtual world of Second Life, we examined spontaneous human skin-covering behavior unhindered by real-world climatic, environmental, and physical variables. Analysis of hundreds of avatars revealed that virtual females disclose substantially more naked skin than virtual males. This phenomenon was not related to avatar hypersexualization as evaluated by measurement of sexually dimorphic body proportions. Furthermore, analysis of skin-covering behavior of a population of culturally homogeneous avatars indicated that the propensity of female avatars to reveal naked skin persisted despite explicit cultural norms promoting less revealing attire. These findings have implications for further understanding how sex-specific aspects of skin disclosure influence human social interactions in both virtual and real settings.

Spin precession in a black hole and naked singularity spacetimes

NASA Astrophysics Data System (ADS)

Chakraborty, Chandrachur; Kocherlakota, Prashant; Joshi, Pankaj S.

2017-02-01

We propose here a specific criterion to address the existence or otherwise of Kerr naked singularities, in terms of the precession of the spin of a test gyroscope due to the frame dragging by the central spinning body. We show that there is indeed an important characteristic difference in the behavior of gyro spin precession frequency in the limit of approach to these compact objects, and this can be used, in principle, to differentiate the naked singularity from a black hole. Specifically, if gyroscopes are fixed all along the polar axis up to the horizon of a Kerr black hole, the precession frequency becomes arbitrarily high, blowing up as the event horizon is approached. On the other hand, in the case of naked singularity, this frequency remains always finite and well behaved. Interestingly, this behavior is intimately related to and is governed by the geometry of the ergoregion in each of these cases, which we analyze here. One intriguing behavior that emerges is, in the Kerr naked singularity case, the Lense-Thirring precession frequency (ΩLT ) of the gyroscope due to frame-dragging effect decreases as (ΩLT∝r ) after reaching a maximum, in the limit of r =0 , as opposed to r-3 dependence in all other known astrophysical cases.

The Naked Mole-Rat Response to Oxidative Stress: Just Deal with It

PubMed Central

Lewis, Kaitlyn N.; Andziak, Blazej; Yang, Ting

2013-01-01

Abstract Significance: The oxidative stress theory of aging has been the most widely accepted theory of aging providing insights into why we age and die for over 50 years, despite mounting evidence from a multitude of species indicating that there is no direct relationship between reactive oxygen species (ROS) and longevity. Here we explore how different species, including the longest lived rodent, the naked mole-rat, have defied the most predominant aging theory. Recent Advances: In the case of extremely long-lived naked mole-rat, levels of ROS production are found to be similar to mice, antioxidant defenses unexceptional, and even under constitutive conditions, naked mole-rats combine a pro-oxidant intracellular milieu with high, steady state levels of oxidative damage. Clearly, naked mole-rats can tolerate this level of oxidative stress and must have mechanisms in place to prevent its translation into potentially lethal diseases. Critical Issues: In addition to the naked mole-rat, other species from across the phylogenetic spectrum and even certain mouse strains do not support this theory. Moreover, overexpressing or knocking down antioxidant levels alters levels of oxidative damage and even cancer incidence, but does not modulate lifespan. Future Directions: Perhaps, it is not oxidative stress that modulates healthspan and longevity, but other cytoprotective mechanisms that allow animals to deal with high levels of oxidative damage and stress, and nevertheless live long, relatively healthy lifespans. Studying these mechanisms in uniquely long-lived species, like the naked mole-rat, may help us tease out the key contributors to aging and longevity. Antioxid. Redox Signal. 19, 1388–1399. PMID:23025341

Effects of drill cuttings on larvae of the cold-water coral Lophelia pertusa

NASA Astrophysics Data System (ADS)

Järnegren, Johanna; Brooke, Sandra; Jensen, Henrik

2017-03-01

Fossil fuel consumption is predicted to dominate energy needs until at least 2040. To make up for reduced production from maturing fields, oil and gas exploration activities on the Norwegian continental shelf have greatly increased over the past several years. Strict emission controls have resulted in a substantial reduction in the release of hazardous chemicals. However, because of the increased exploration the discharges of water-based drill cuttings and muds have increased substantially, temporarily increasing water column sediment loads. The stony coral Lophelia pertusa is the most widely distributed and well-studied of the structure forming cold water corals (CWC) and it thrives in Norwegian waters where many reefs are located in the vicinity of oil platforms or exploration areas. This species provides habitat for a diverse and abundant assemblage of invertebrates and fishes, including commercially valuable species. High sediment loads are known to negatively affect adult corals, but impacts on the early life history stages are unknown. We investigated the effects of a range of drill cutting concentrations (0.5-640 ppm) on larvae of L. pertusa at ages five days and 15-20 days. One set of experiments was conducted in static experimental chambers that exposed larvae to decreasing concentrations over time, and the other maintained continuous drill cutting concentrations for the duration of the experiment (24 h). Increased sediment load for a duration of 24 h caused significant larval mortality, but there was an age-dependent difference in sensitivity of larvae. Younger larvae were significantly more susceptible to lower concentrations of drill cuttings than older larvae, while the older larvae were significantly more affected at higher concentrations. Five day old larvae were affected at treatment concentration 40 ppm. The larval cilia became clogged, preventing the larvae from swimming actively and ultimately causing mortality. Larvae of many species use cilia

PpYUC11, a strong candidate gene for the stony hard phenotype in peach (Prunus persica L. Batsch), participates in IAA biosynthesis during fruit ripening

PubMed Central

Pan, Lei; Zeng, Wenfang; Niu, Liang; Lu, Zhenhua; Liu, Hui; Cui, Guochao; Zhu, Yunqin; Chu, Jinfang; Li, Weiping; Fang, Weichao; Cai, Zuguo; Li, Guohuai; Wang, Zhiqiang

2015-01-01

High concentrations of indole-3-acetic acid (IAA) are required for climacteric ethylene biosynthesis to cause fruit softening in melting flesh peaches at the late ripening stage. By contrast, the fruits of stony hard peach cultivars do not soften and produce little ethylene due to the low IAA concentrations. To investigate the regulation of IAA accumulation during peach ripening [the transition from stage S3 to stage S4 III (climacteric)], a digital gene expression (DGE) analysis was performed. The expression patterns of auxin-homeostasis-related genes were compared in fruits of the melting flesh peach ‘Goldhoney 3’ and the stony hard flesh peach ‘Yumyeong’ during the ripening stage. It is revealed here that a YUCCA flavin mono-oxygenase gene (PpYUC11, ppa008176m), a key gene in auxin biosynthesis, displayed an identical differential expression profile to the profiles of IAA accumulation and PpACS1 transcription: the mRNA transcripts increased at the late ripening stage in melting flesh peaches but were below the limit of detection in mature fruits of stony hard peaches. In addition, the strong association between intron TC microsatellite genotypes of PpYUC11 and the flesh texture (normal or stony hard) is described in 43 peach varieties, indicating that this locus may be responsible for the stony hard phenotype in peach. These findings support the hypothesis that PpYUC11 may play an essential role in auxin biosynthesis during peach fruit ripening and is a candidate gene for the control of the stony hard phenotype in peach. PMID:26307136

Large-area imaging reveals biologically driven non-random spatial patterns of corals at a remote reef

NASA Astrophysics Data System (ADS)

Edwards, Clinton B.; Eynaud, Yoan; Williams, Gareth J.; Pedersen, Nicole E.; Zgliczynski, Brian J.; Gleason, Arthur C. R.; Smith, Jennifer E.; Sandin, Stuart A.

2017-12-01

For sessile organisms such as reef-building corals, differences in the degree of dispersion of individuals across a landscape may result from important differences in life-history strategies or may reflect patterns of habitat availability. Descriptions of spatial patterns can thus be useful not only for the identification of key biological and physical mechanisms structuring an ecosystem, but also by providing the data necessary to generate and test ecological theory. Here, we used an in situ imaging technique to create large-area photomosaics of 16 plots at Palmyra Atoll, central Pacific, each covering 100 m2 of benthic habitat. We mapped the location of 44,008 coral colonies and identified each to the lowest taxonomic level possible. Using metrics of spatial dispersion, we tested for departures from spatial randomness. We also used targeted model fitting to explore candidate processes leading to differences in spatial patterns among taxa. Most taxa were clustered and the degree of clustering varied by taxon. A small number of taxa did not significantly depart from randomness and none revealed evidence of spatial uniformity. Importantly, taxa that readily fragment or tolerate stress through partial mortality were more clustered. With little exception, clustering patterns were consistent with models of fragmentation and dispersal limitation. In some taxa, dispersion was linearly related to abundance, suggesting density dependence of spatial patterning. The spatial patterns of stony corals are non-random and reflect fundamental life-history characteristics of the taxa, suggesting that the reef landscape may, in many cases, have important elements of spatial predictability.

Magnetic particles extracted from manganese nodules: Suggested origin from stony and iron meteorites

USGS Publications Warehouse

Finkelman, R.B.

1970-01-01

On the basis of x-ray diffraction and electron microprobe data, spherical and ellipsoidal particles extracted from manganese nodules were divided into three groups. Group I particles are believed to be derived from iron meteorites, and Group II particles from stony meteorites. Group III particles are believed to be volcanic in origin.

Enhancing Inquiry, Evidence-Based Reflection, and Integrative Learning with the Lifelong ePortfolio Process: The Implementation of Integrative ePortfolios at Stony Brook University

ERIC Educational Resources Information Center

Wozniak, Nancy McCoy

2013-01-01

Reflection plays a critical role in moving learning to the next level of inquiry. Stony Brook University has adopted an approach to using ePortfolios within the curriculum that emphasizes reflection. Stony Brook University successfully piloted ePortfolios in the Fall 2010 Semester and discovered their use facilitated the inquiry process for the…

Spectral response of the coral rubble, living corals, and dead corals: study case on the Spermonde Archipelago, Indonesia

NASA Astrophysics Data System (ADS)

Nurdin, Nurjannah; Komatsu, Teruhisa; Yamano, Hiroya; Arafat, Gulam; Rani, Chair; Akbar AS, M.

2012-10-01

Coral reefs play important ecological services such as providing foods, biodiversity, nutrient recycling etc. for human society. On the other hand, they are threatened by human impacts such as illegal fishing and environmental changes such as rises of sea water temperature and sea level due to global warming. Thus, it is very important to monitor dynamic spatial distributions of coral reefs and related habitats such as coral rubble, dead coral, bleached corals, seagrass, etc. Hyperspectral data, in particular, offer high potential for characterizing and mapping coral reefs because of their capability to identify individual reef components based on their detailed spectral response. We studied the optical properties by measuring in situ spectra of living corals, dead coral and coral rubble covered with algae. Study site was selected in Spermonde archipelago, South Sulawesi, Indonesia because this area is included in the highest diversity of corals in the world named as Coral Triangle, which is recognized as the global centre of marine biodiversity and a global priority for conservation. Correlation analysis and cluster analysis support that there are distinct differences in reflectance spectra among categories. Common spectral characteristic of living corals, dead corals and coral rubble covered with algae was a reflectance minimum at 674 nm. Healthy corals, dead coral covered with algae and coral rubble covered with algae showed high similarity of spectral reflectance. It is estimated that this is due to photsynthetic pigments.

Naked-eye 3D imaging employing a modified MIMO micro-ring conjugate mirrors

NASA Astrophysics Data System (ADS)

Youplao, P.; Pornsuwancharoen, N.; Amiri, I. S.; Thieu, V. N.; Yupapin, P.

2018-03-01

In this work, the use of a micro-conjugate mirror that can produce the 3D image incident probe and display is proposed. By using the proposed system together with the concept of naked-eye 3D imaging, a pixel and a large volume pixel of a 3D image can be created and displayed as naked-eye perception, which is valuable for the large volume naked-eye 3D imaging applications. In operation, a naked-eye 3D image that has a large pixel volume will be constructed by using the MIMO micro-ring conjugate mirror system. Thereafter, these 3D images, formed by the first micro-ring conjugate mirror system, can be transmitted through an optical link to a short distance away and reconstructed via the recovery conjugate mirror at the other end of the transmission. The image transmission is performed by the Fourier integral in MATLAB and compares to the Opti-wave program results. The Fourier convolution is also included for the large volume image transmission. The simulation is used for the manipulation, where the array of a micro-conjugate mirror system is designed and simulated for the MIMO system. The naked-eye 3D imaging is confirmed by the concept of the conjugate mirror in both the input and output images, in terms of the four-wave mixing (FWM), which is discussed and interpreted.

Kin discrimination and female mate choice in the naked mole-rat Heterocephalus glaber.

PubMed

Clarke, F M; Faulkes, C G

1999-10-07

Naked mole-rats are fossorial, eusocial rodents that naturally exhibit high levels of inbreeding. Persistent inbreeding in animals often results in a substantial decline in fitness and, thus, dispersal and avoidance of kin as mates are two common inbreeding avoidance mechanisms. In the naked mole-rat evidence for the former has recently been found. Here we address the latter mechanism by investigating kin recognition and female mate choice using a series of choice tests in which the odour, social and mate preferences of females were determined. Discrimination by females appears to be dependent on their reproductive status. Reproductively active females prefer to associate with unfamiliar males, whereas reproductively inactive females do not discriminate. Females do not discriminate between kin and non-kin suggesting that the criterion for recognition is familiarity, not detection of genetic similarity per se. In the wild, naked mole-rats occupy discrete burrow systems and dispersal and mixing with non-kin is thought to be comparatively rare. Thus, recognition by familiarity may function as a highly efficient kin recognition mechanism in the naked mole-rat. A preference by reproductively active females for unfamiliar males is interpreted as inbreeding avoidance. These findings suggest that, despite an evolutionary history of close inbreeding, naked mole-rats may not be exempt from the effects of inbreeding depression and will attempt to outbreed should the opportunity arise.

Evidence of host-associated divergence from coral-eating snails (genus Coralliophila) in the Coral Triangle

NASA Astrophysics Data System (ADS)

Simmonds, Sara E.; Chou, Vincent; Cheng, Samantha H.; Rachmawati, Rita; Calumpong, Hilconida P.; Ngurah Mahardika, G.; Barber, Paul H.

2018-06-01

We studied how host-associations and geography shape the genetic structure of sister species of marine snails Coralliophila radula (A. Adams, 1853) and C. violacea (Kiener, 1836). These obligate ectoparasites prey upon corals and are sympatric throughout much of their ranges in coral reefs of the tropical and subtropical Indo-Pacific. We tested for population genetic structure of snails in relation to geography and their host corals using mtDNA (COI) sequences in minimum spanning trees and AMOVAs. We also examined the evolutionary relationships of their Porites host coral species using maximum likelihood trees of RAD-seq (restriction site-associated DNA sequencing) loci mapped to a reference transcriptome. A maximum likelihood tree of host corals revealed three distinct clades. Coralliophila radula showed a pronounced genetic break across the Sunda Shelf ( Φ CT = 0.735) but exhibited no genetic structure with respect to host. C. violacea exhibited significant geographic structure ( Φ CT = 0.427), with divergence among Hawaiian populations, the Coral Triangle and the Indian Ocean. Notably, C. violacea showed evidence of ecological divergence; two lineages were associated with different groups of host coral species, one widespread found at all sites, and the other restricted to the Coral Triangle. Sympatric populations of C. violacea found on different suites of coral species were highly divergent ( Φ CT = 0.561, d = 5.13%), suggesting that symbiotic relationships may contribute to lineage diversification in the Coral Triangle.

Gravitational radiation from a cylindrical naked singularity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakao, Ken-ichi; Morisawa, Yoshiyuki

We construct an approximate solution which describes the gravitational emission from a naked singularity formed by the gravitational collapse of a cylindrical thick shell composed of dust. The assumed situation is that the collapsing speed of the dust is very large. In this situation, the metric variables are obtained approximately by a kind of linear perturbation analysis in the background Morgan solution which describes the motion of cylindrical null dust. The most important problem in this study is what boundary conditions for metric and matter variables should be imposed at the naked singularity. We find a boundary condition that allmore » the metric and matter variables are everywhere finite at least up to the first order approximation. This implies that the spacetime singularity formed by this high-speed dust collapse is very similar to that formed by the null dust and the final singularity will be a conical one. Weyl curvature is completely released from the collapsed dust.« less

State University of New York at Stony Brook Main Library Circulation Department Procedures Manual.

ERIC Educational Resources Information Center

Kendrick, Curtis L., Comp.; Lange, Robert, Comp.

Designed to train student circulation desk workers at the State University of New York at Stony Brook's Main Library, this guide details specific procedures and outlines administrative policies. Topics covered include: (1) what circulation is; (2) what is expected of graduate students; (3) the library's opening and closing procedures; (4) who may…

Infrared (2.08-14 micron) spectra of powered stony meteorites

NASA Technical Reports Server (NTRS)

Salisbury, J. W.; Daria, D. M.; Jarosewich, E.

1991-01-01

Infrared biconical reflectance spectra of 60 powdered meteorite samples, representing 50 different stony meteorites, were measured as analogues of asteroidal regolith. Representative samples were measured in directional hemispherical reflectance to assure that Kirchhoff's Law can be used to predict relative emissivity from the reflectance spectra. These spectral data confirm that the O-H fundamental absorption band near 2.9 microns is an extremely sensitive indicator of incipient alteration, which often has taken place in powdered meteorite samples exposed only to water vapor in the air. Such non-carbonaceous samples typically contain less than 1 percent water by weight. Likewise, the C-H fundamental absorption bands near 3.4 and 3.5 microns are equally sensitive indicators of contamination with volatile hydrocarbons, which can also be absorbed from the air. The heavy, macromolecular hydrocarbons native to chondrites do not display such heavy bands, making detection of these bands in remote sensing of asteroids unlikely. Despite the spectral artifacts introduced by alteration and hydrocarbon contamination, powdered stony meteorites display a wide variety of real spectral features that can be used for their identification, including residual reststrahlen bands, absorption bands, and the Christiansen feature. Researchers found that the wavelengths of the peaks or troughs of each of these spectral features can be used independently to infer meteorite composition, but the best results are obtained when the entire spectral curve is used, or at least the portion of it encompassed by the 8 to 14 micron atmospheric window, in a digital search library.

Coral microbiology

USGS Publications Warehouse

Rosenberg, Eugene; Kellogg, Christina A.; Rohwer, Forest

2007-01-01

In the last 30 years, there has been approximately a 30% loss of corals worldwide, largely due to emerging diseases (Harvell et al., 2002, 2007; Hughes et al., 2003). Coral microbiology is a new field, driven largely by a desire to understand the interactions between corals and their symbiotic microorganisms and to use this knowledge to eventually prevent the spread of coral diseases.

Beneficial Microorganisms for Corals (BMC): Proposed Mechanisms for Coral Health and Resilience.

PubMed

Peixoto, Raquel S; Rosado, Phillipe M; Leite, Deborah Catharine de Assis; Rosado, Alexandre S; Bourne, David G

2017-01-01

The symbiotic association between the coral animal and its endosymbiotic dinoflagellate partner Symbiodinium is central to the success of corals. However, an array of other microorganisms associated with coral (i.e., Bacteria, Archaea, Fungi, and viruses) have a complex and intricate role in maintaining homeostasis between corals and Symbiodinium . Corals are sensitive to shifts in the surrounding environmental conditions. One of the most widely reported responses of coral to stressful environmental conditions is bleaching. During this event, corals expel Symbiodinium cells from their gastrodermal tissues upon experiencing extended seawater temperatures above their thermal threshold. An array of other environmental stressors can also destabilize the coral microbiome, resulting in compromised health of the host, which may include disease and mortality in the worst scenario. However, the exact mechanisms by which the coral microbiome supports coral health and increases resilience are poorly understood. Earlier studies of coral microbiology proposed a coral probiotic hypothesis, wherein a dynamic relationship exists between corals and their symbiotic microorganisms, selecting for the coral holobiont that is best suited for the prevailing environmental conditions. Here, we discuss the microbial-host relationships within the coral holobiont, along with their potential roles in maintaining coral health. We propose the term BMC (Beneficial Microorganisms for Corals) to define (specific) symbionts that promote coral health. This term and concept are analogous to the term Plant Growth Promoting Rhizosphere (PGPR), which has been widely explored and manipulated in the agricultural industry for microorganisms that inhabit the rhizosphere and directly or indirectly promote plant growth and development through the production of regulatory signals, antibiotics and nutrients. Additionally, we propose and discuss the potential mechanisms of the effects of BMC on corals, suggesting

Beneficial Microorganisms for Corals (BMC): Proposed Mechanisms for Coral Health and Resilience

PubMed Central

Peixoto, Raquel S.; Rosado, Phillipe M.; Leite, Deborah Catharine de Assis; Rosado, Alexandre S.; Bourne, David G.

2017-01-01

The symbiotic association between the coral animal and its endosymbiotic dinoflagellate partner Symbiodinium is central to the success of corals. However, an array of other microorganisms associated with coral (i.e., Bacteria, Archaea, Fungi, and viruses) have a complex and intricate role in maintaining homeostasis between corals and Symbiodinium. Corals are sensitive to shifts in the surrounding environmental conditions. One of the most widely reported responses of coral to stressful environmental conditions is bleaching. During this event, corals expel Symbiodinium cells from their gastrodermal tissues upon experiencing extended seawater temperatures above their thermal threshold. An array of other environmental stressors can also destabilize the coral microbiome, resulting in compromised health of the host, which may include disease and mortality in the worst scenario. However, the exact mechanisms by which the coral microbiome supports coral health and increases resilience are poorly understood. Earlier studies of coral microbiology proposed a coral probiotic hypothesis, wherein a dynamic relationship exists between corals and their symbiotic microorganisms, selecting for the coral holobiont that is best suited for the prevailing environmental conditions. Here, we discuss the microbial-host relationships within the coral holobiont, along with their potential roles in maintaining coral health. We propose the term BMC (Beneficial Microorganisms for Corals) to define (specific) symbionts that promote coral health. This term and concept are analogous to the term Plant Growth Promoting Rhizosphere (PGPR), which has been widely explored and manipulated in the agricultural industry for microorganisms that inhabit the rhizosphere and directly or indirectly promote plant growth and development through the production of regulatory signals, antibiotics and nutrients. Additionally, we propose and discuss the potential mechanisms of the effects of BMC on corals, suggesting

To understand coral disease, look at coral cells

USGS Publications Warehouse

Work, Thierry M.; Meteyer, Carol U.

2014-01-01

Diseases threaten corals globally, but 40 years on their causes remain mostly unknown. We hypothesize that inconsistent application of a complete diagnostic approach to coral disease has contributed to this slow progress. We quantified methods used to investigate coral disease in 492 papers published between 1965 and 2013. Field surveys were used in 65% of the papers, followed by biodetection (43%), laboratory trials (20%), microscopic pathology (21%), and field trials (9%). Of the microscopic pathology efforts, 57% involved standard histopathology at the light microscopic level (12% of the total investigations), with the remainder dedicated to electron or fluorescence microscopy. Most (74%) biodetection efforts focused on culture or molecular characterization of bacteria or fungi from corals. Molecular and immunological tools have been used to incriminate infectious agents (mainly bacteria) as the cause of coral diseases without relating the agent to specific changes in cell and tissue pathology. Of 19 papers that declared an infectious agent as a cause of disease in corals, only one (5%) used microscopic pathology, and none fulfilled all of the criteria required to satisfy Koch’s postulates as applied to animal diseases currently. Vertebrate diseases of skin and mucosal surfaces present challenges similar to corals when trying to identify a pathogen from a vast array of environmental microbes, and diagnostic approaches regularly used in these cases might provide a model for investigating coral diseases. We hope this review will encourage specialists of disease in domestic animals, wildlife, fish, shellfish, and humans to contribute to the emerging field of coral disease.

Learning to Communicate Science: Stony Brook University's Approach

NASA Astrophysics Data System (ADS)

Bass, E.

2012-12-01

Stony Brook University offers an unusual series of short courses to help science graduate students learn to communicate more effectively about science with people outside their disciplines, including the public, public officials, potential funders and employers, students, the press, and colleagues in other fields. The courses include six 1-credit (14-hour) modules in oral and written communication that rely on practice and interactive feedback. More than 120 master's and PhD students, from more than 16 departments, have taken at least one of the courses since spring 2011. Most students who try one module end up taking two or three. An additional course for medical and nursing students was added in fall 2012. The courses are offered in the School of Journalism and were developed by the Center for Communicating Science (CCS). CCS was founded in 2009, with the participation of Alan Alda, the actor, writer, and longtime advocate for science, who is a Visiting Professor at Stony Brook. The Communicating Science courses have received strong institutional support and enthusiastic reviews. They are required by two programs, an MA in Marine Conservation and Policy and an Advanced Certificate in Health Communications. Two successive Provosts have subsidized course costs for PhD students, and Graduate School leaders are working to establish a steady funding stream to allow expansion of the program. Our aspiration at CCS is for every science graduate student to receive some training in communicating about science to the public. Several factors have helped in establishing the program: --CCS' multidisciplinary nature helped build support, with participation by faculty from across the campus, including not only the natural sciences, engineering, and medicine, but journalism, theatre arts, and the Writing Program, as well as nearby Brookhaven National Laboratory and Cold Spring Harbor Laboratory. --Before offering courses, CCS conducted all-day workshops and high

The fields of a naked singularity and a black hole in mutual equilibrium

NASA Astrophysics Data System (ADS)

Paolino, Armando; Pizzi, Marco

2008-01-01

Recently Alekseev and Belinski have presented a new exact solution of the Einstein-Maxwell equation which describes two Reissner-Nordstrom (RN) sources in reciprocal equilibrium (no struts nor strings) one source is a naked singularity, the other is a black hole. In this paper we use the Alekseev-Belinki solution in the special case in which the charge of the black hole is zero-therefore we have a naked singularity near a neutral black hole. We give the plots of the electric force lines in both the cases in which the naked singularity has a mass comparable with the black hole and in which it is much smaller. The analysis of this latter case confirm the goodness of the Hanni-Ruffini approximation.

Orbiting naked singularities in large-ω Brans-Dicke gravity

NASA Astrophysics Data System (ADS)

Chauvineau, Bertrand

2017-11-01

Brans-Dicke gravity admits spherical solutions describing naked singularities rather than black holes. Depending on some parameters entering such a solution, stable circular orbits exist for all radii. One shows that, despite the fact a naked singularity is an infinite redshift location, the far observed orbital motion frequency is unbounded for an adiabatically decreasing radius. We then argue that this feature remains true in a wide set of scalar(s)-tensor theories if gravity. This is a salient difference with general relativity, and the repercussion on the gravitational radiation by EMRI systems is stressed. Since this behaviour survives the ω \\longrightarrow ∞ limit, the possibility of such solutions is of utmost interest in the new gravitational wave astronomy context, despite the current constraints on scalar-tensor gravity.

Naked Black Hole Firewalls.

PubMed

Chen, Pisin; Ong, Yen Chin; Page, Don N; Sasaki, Misao; Yeom, Dong-Han

2016-04-22

In the firewall proposal, it is assumed that the firewall lies near the event horizon and should not be observable except by infalling observers, who are presumably terminated at the firewall. However, if the firewall is located near where the horizon would have been, based on the spacetime evolution up to that time, later quantum fluctuations of the Hawking emission rate can cause the "teleological" event horizon to have migrated to the inside of the firewall location, rendering the firewall naked. In principle, the firewall can be arbitrarily far outside the horizon. This casts doubt about the notion that firewalls are the "most conservative" solution to the information loss paradox.

Naked Black Hole Firewalls

NASA Astrophysics Data System (ADS)

Chen, Pisin; Ong, Yen Chin; Page, Don N.; Sasaki, Misao; Yeom, Dong-han

2016-04-01

In the firewall proposal, it is assumed that the firewall lies near the event horizon and should not be observable except by infalling observers, who are presumably terminated at the firewall. However, if the firewall is located near where the horizon would have been, based on the spacetime evolution up to that time, later quantum fluctuations of the Hawking emission rate can cause the "teleological" event horizon to have migrated to the inside of the firewall location, rendering the firewall naked. In principle, the firewall can be arbitrarily far outside the horizon. This casts doubt about the notion that firewalls are the "most conservative" solution to the information loss paradox.

Characterization of Fluorescence in the Marine Environment

DTIC Science & Technology

2007-06-14

fluorescence data. RESULTS We made the first in situ observations of fluorescence in deepwater organisms, including corals, anemones , crinoids...project, they resulted in the discovery of fluorescence in a shark, a greeneye fish (Chlorophthalmus agassizi) (Figure 2), an anemone , a starfish, a sea...Scyphozoa), and the box jellies (Class Cubozoa). The Class Anthozoa includes the stony corals, anemones , and zoanthids (Subclass Zooantharia

Improved thermal stability of oxide-supported naked gold nanoparticles by ligand-assisted pinning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, C; Divins, N. J.; Gazquez, Jaume

We report a method to improve the thermal stability, up to 900 C, of bare-metal (naked) gold nanoparticles supported on top of SiO{sub 2} and SrTiO{sub 3} substrates via ligand-assisted pinning. This approach leads to monodisperse naked gold nanoparticles without significant sintering after thermal annealing in air at 900 C. The ligand-assisted pinning mechanism is described.

Optimizing the Hydrological and Biogeochemical Simulations on a Hillslope with Stony Soil

NASA Astrophysics Data System (ADS)

Zhu, Q.

2017-12-01

Stony soils are widely distributed in the hilly area. However, traditional pedotransfer functions are not reliable in predicting the soil hydraulic parameters for these soils due to the impacts of rock fragments. Therefore, large uncertainties and errors may exist in the hillslope hydrological and biogeochemical simulations in stony soils due to poor estimations of soil hydraulic parameters. In addition, homogenous soil hydraulic parameters are usually used in traditional hillslope simulations. However, soil hydraulic parameters are spatially heterogeneous on the hillslope. This may also cause the unreliable simulations. In this study, we obtained soil hydraulic parameters using five different approaches on a tea hillslope in Taihu Lake basin, China. These five approaches included (1) Rossetta predicted and spatially homogenous, (2) Rossetta predicted and spatially heterogeneous), (3) Rossetta predicted, rock fragment corrected and spatially homogenous, (4) Rossetta predicted, rock fragment corrected and spatially heterogeneous, and (5) extracted from observed soil-water retention curves fitted by dual-pore function and spatially heterogeneous (observed). These five sets of soil hydraulic properties were then input into Hydrus-3D and DNDC to simulate the soil hydrological and biogeochemical processes. The aim of this study is testing two hypotheses. First, considering the spatial heterogeneity of soil hydraulic parameters will improve the simulations. Second, considering the impact of rock fragment on soil hydraulic parameters will improve the simulations.

Discoveries and Conservation Efforts of Extensive Deep-Sea Coral Habitat off the Southeastern U.S.

NASA Astrophysics Data System (ADS)

Reed, J. K.; Messing, C. G.; Walker, B. K.; Farrington, S.; Brooke, S.; Correa, T.; Brouwer, M.

2012-12-01

The deep-sea floor of the Western Atlantic off the southeastern U.S. supports a variety of deep-sea coral ecosystem (DSCE) habitats, including: coral mounds, rock terraces (Miami and Pourtalès Terraces), canyons (Agassiz and Tortugas Valleys), and island slopes (western Bahamas and northern Cuba). We used NOAA bathymetric contour maps and digital elevation models to identify and delineate the areal extent of potential DSCE habitat (50-1000 m) from northeastern Florida through the Straits of Florida. Recently, shipboard and AUV side-scan and multibeam sonar have further documented portions of the region. The resulting maps have been ground-truthed with over 250 submersible and remotely operated vehicle (ROV) dives, revealing that high-relief topographic features, including steep escarpments and rocky terraces, are good predictors of DSCE habitat in this region. The benthic biota is diverse but locally variable; for example, Lophelia and Enallopsammia stony corals dominate the deep-water mounds, whereas stylasterid corals dominate the rocky terraces where Lophelia is sporadic. Octocorals, black corals, and sponges are common at most sites but different species exhibit site-specific distributional variability. In 2011, the first of two NOAA-sponsored cruises using sonar mapping and an ROV discovered the southernmost Lophelia coral mound in the continental United States, south of the Florida Keys, offering the possibility that more Lophelia mounds may exist in this region where they were previously thought to be absent. The second cruise discovered that deep-water Oculina varicosa coral reefs extend over 70 nmi north of the current boundaries of the Oculina Habitat Area of Particular Concern (OHAPC), which was first designated as a marine protected area in 1984. These studies indicate that cold-water coral mounds are significantly more diverse and abundant in this region than previously thought. These research results were presented to NOAA and the South Atlantic

Optical effects related to Keplerian discs orbiting Kehagias-Sfetsos naked singularities

NASA Astrophysics Data System (ADS)

Stuchlík, Zdeněk; Schee, Jan

2014-10-01

We demonstrate possible optical signatures of the Kehagias-Sfetsos (KS) naked singularity spacetimes representing a spherically symmetric vacuum solution of the modified Hořava gravity. In such spacetimes, accretion structures significantly different from those present in standard black hole spacetimes occur due to the ‘antigravity’ effect, which causes an internal static sphere surrounded by Keplerian discs. We focus our attention on the optical effects related to the Keplerian accretion discs, constructing the optical appearance of the Keplerian discs, the spectral continuum due to their thermal radiation, and the spectral profiled lines generated in the innermost parts of such discs. The KS naked singularity signature is strongly encoded in the characteristics of predicted optical effects, especially in cases where the spectral continuum and spectral lines are profiled by the strong gravity of the spacetimes due to the vanishing region of the angular velocity gradient influencing the effectiveness of the viscosity mechanism. We can conclude that optical signatures of KS naked singularities can be well distinguished from the signatures of standard black holes.

Corals diseases are a major cause of coral death

EPA Science Inventory

Corals, like humans, are susceptible to diseases. Some coral diseases are associated with pathogenic bacteria; however, the causes of most remain unknown. Some diseases trigger rapid and extensive mortality, while others slowly cause localized color changes or injure coral tiss...

Back to Basics: Naked-Eye Astronomical Observation

ERIC Educational Resources Information Center

Barclay, Charles

2003-01-01

For pupils of both sexes and all ages from about six upwards, the subject of Astronomy holds many fascinations--the rapid changes in knowledge, the large resource of available IT packages and above all the beautiful pictures from Hubble and the large Earth-based telescopes. This article, however, stresses the excitement and importance of naked-eye…

Vibrio Zinc-Metalloprotease Causes Photoinactivation of Coral Endosymbionts and Coral Tissue Lesions

PubMed Central

Sussman, Meir; Mieog, Jos C.; Doyle, Jason; Victor, Steven; Willis, Bette L.; Bourne, David G.

2009-01-01

Background Coral diseases are emerging as a serious threat to coral reefs worldwide. Of nine coral infectious diseases, whose pathogens have been characterized, six are caused by agents from the family Vibrionacae, raising questions as to their origin and role in coral disease aetiology. Methodology/Principal Findings Here we report on a Vibrio zinc-metalloprotease causing rapid photoinactivation of susceptible Symbiodinium endosymbionts followed by lesions in coral tissue. Symbiodinium photosystem II inactivation was diagnosed by an imaging pulse amplitude modulation fluorometer in two bioassays, performed by exposing Symbiodinium cells and coral juveniles to non-inhibited and EDTA-inhibited supernatants derived from coral white syndrome pathogens. Conclusion/Significance These findings demonstrate a common virulence factor from four phylogenetically related coral pathogens, suggesting that zinc-metalloproteases may play an important role in Vibrio pathogenicity in scleractinian corals. PMID:19225559

Immuno Nanosensor for the Ultrasensitive Naked Eye Detection of Tuberculosis.

PubMed

Mohd Bakhori, Noremylia; Yusof, Nor Azah; Abdullah, Jaafar; Wasoh, Helmi; Md Noor, Siti Suraiya; Ahmad Raston, Nurul Hanun; Mohammad, Faruq

2018-06-14

In the present study, a beneficial approach for the ultrasensitive and affordable naked eye detection and diagnosis of tuberculosis (TB) by utilizing plasmonic enzyme-linked immunosorbent assay (ELISA) via antibody-antigen interaction was studied. Here, the biocatalytic cycle of the intracellular enzymes links to the formation and successive growth of the gold nanoparticles (GNPs) for ultrasensitive detection. The formation of different colored solutions by the plasmonic nanoparticles in the presence of enzyme labels links directly to the existence or non-existence of the TB analytes in the sample solutions. For disease detection, the adapted protocol is based mainly on the conventional ELISA procedure that involves catalase-labeled antibodies, i.e., the enzymes consume hydrogen peroxide and further produce GNPs with the addition of gold (III) chloride. The amount of hydrogen peroxide remaining in the solution determines whether the GNPs solution is to be formed in the color blue or the color red, as it serves as a confirmation for the naked eye detection of TB analytes. However, the conventional ELISA method only shows tonal colors that need a high concentration of analyte to achieve high confidence levels for naked eye detection. Also, in this research, we proposed the incorporation of protein biomarker, Mycobacterium tuberculosis ESAT-6-like protein esxB (CFP-10), as a means of TB detection using plasmonic ELISA. With the use of this technique, the CFP-10 detection limit can be lowered to 0.01 µg/mL by the naked eye. Further, our developed technique was successfully tested and confirmed with sputum samples from patients diagnosed with positive TB, thereby providing enough evidence for the utilization of our technique in the early diagnosis of TB disease.

Coral transplantation triggers shift in microbiome and promotion of coral disease associated potential pathogens

PubMed Central

Casey, Jordan M.; Connolly, Sean R.; Ainsworth, Tracy D.

2015-01-01

By cultivating turf algae and aggressively defending their territories, territorial damselfishes in the genus Stegastes play a major role in shaping coral-algal dynamics on coral reefs. The epilithic algal matrix (EAM) inside Stegastes’ territories is known to harbor high abundances of potential coral disease pathogens. To determine the impact of territorial grazers on coral microbial assemblages, we established a coral transplant inside and outside of Stegastes’ territories. Over the course of one year, the percent mortality of transplanted corals was monitored and coral samples were collected for microbial analysis. As compared to outside damselfish territories, Stegastes were associated with a higher rate of mortality of transplanted corals. However, 16S rDNA sequencing revealed that territorial grazers do not differentially impact the microbial assemblage of corals exposed to the EAM. Regardless of Stegastes presence or absence, coral transplantation resulted in a shift in the coral-associated microbial community and an increase in coral disease associated potential pathogens. Further, transplanted corals that suffer low to high mortality undergo a microbial transition from a microbiome similar to that of healthy corals to that resembling the EAM. These findings demonstrate that coral transplantation significantly impacts coral microbial communities, and transplantation may increase susceptibility to coral disease. PMID:26144865

Erosion on very stony forest soil during phenomenal rain in Webster County, West Virginia

Treesearch

J. H. Patric; W. E., Jr. Kidd

1982-01-01

On July 15 and 16, 1979, at least 6 inches of rain fell in central West Virginia during 3 hours, a storm of return period longer than 1,000 years. More than 6 miles of logging roads were examined for evidences of soil erosion and sediment delivery to streams. Erosion was negligible on very stony soils where (a) logging roads were litter covered, (b) road grades were...

Loss of live coral compromises predator-avoidance behaviour in coral reef damselfish.

PubMed

Boström-Einarsson, Lisa; Bonin, Mary C; Munday, Philip L; Jones, Geoffrey P

2018-05-17

Tropical reefs have experienced an unprecedented loss of live coral in the past few decades and the biodiversity of coral-dependent species is under threat. Many reef fish species decline in abundance as coral cover is lost, yet the mechanisms responsible for these losses are largely unknown. A commonly hypothesised cause of fish decline is the loss of shelter space between branches as dead corals become overgrown by algae. Here we tested this hypothesis by quantifying changes in predator-avoidance behaviour of a common damselfish, Pomacentrus moluccensis, before and after the death of their coral colony. Groups of P. moluccensis were placed on either healthy or degraded coral colonies, startled using a visual stimulus and their sheltering responses compared over a 7-week period. P. moluccensis stopped sheltering amongst the coral branches immediately following the death of the coral, despite the presence of ample shelter space. Instead, most individuals swam away from the dead coral, potentially increasing their exposure to predators. It appears that the presence of live coral rather than shelter per se is the necessary cue that elicits the appropriate behavioural response to potential predators. The disruption of this link poses an immediate threat to coral-associated fishes on degrading reefs.

Growth of a Science Center: The Center for Science and Mathematics Education (CESAME) at Stony Brook University

ERIC Educational Resources Information Center

Gafney, Leo; Bynum, R. David; Sheppard, Keith

2015-01-01

This report describes the origin and development of CESAME (The Center for Science and Mathematics Education) at Stony Brook University. The analysis identifies key ingredients in areas of personnel, funding, organizational structures, educational priorities, collaboration, and institutionalization. After a discussion of relevant issues in…

Effects of coral bleaching on the obligate coral-dwelling crab Trapezia cymodoce

NASA Astrophysics Data System (ADS)

Stella, J. S.; Munday, P. L.; Jones, G. P.

2011-09-01

Corals are an essential and threatened habitat for a diverse range of reef-associated animals. Episodes of coral bleaching are predicted to increase in frequency and intensity over coming decades, yet the effects of coral-host bleaching on the associated animal communities remain poorly understood. The present study investigated the effects of host-colony bleaching on the obligate coral-dwelling crab, Trapezia cymodoce, during a natural bleaching event in the lagoon of Lizard Island, Australia. Branching corals, which harbour the highest diversity of coral associates, comprised 13% of live coral cover at the study site, with 83% affected by bleaching. Crabs on healthy and bleached colonies of Pocillopora damicornis were monitored over a 5-week period to determine whether coral bleaching affected crab density and movement patterns. All coral colonies initially contained one breeding pair of crabs. There was a significant decline in crab density on bleached corals after 5 weeks, with many corals losing one or both crabs, yet all healthy colonies retained a mating pair. Fecundity of crabs collected from bleached and healthy colonies of P. damicornis was also compared. The size of egg clutches of crabs collected from bleached hosts was 40% smaller than those from healthy hosts, indicating a significant reduction in fecundity. A laboratory experiment on movement patterns found that host-colony bleaching also prompted crabs to emigrate in search of more suitable colonies. Emigrant crabs engaged in aggressive interactions with occupants of healthy hosts, with larger crabs always usurping occupants of a smaller size. Decreased densities and clutch sizes, along with increased competitive interactions, could potentially result in a population decline of these important coral associates with cascading effects on coral health.

Density-associated recruitment mediates coral population dynamics on a coral reef

NASA Astrophysics Data System (ADS)

Bramanti, Lorenzo; Edmunds, Peter J.

2016-06-01

Theory suggests that density-associated processes can modulate community resilience following declines in population size. Here, we demonstrate density-associated processes in two scleractinian populations on the outer reef of Moorea, French Polynesia, that are rapidly increasing in size following the effects of two catastrophic disturbances. Between 2006 and 2010, predation by the corallivorous crown-of-thorns sea star reduced coral cover by 93 %; in 2010, the dead coral skeletons were removed by a cyclone, and in 2011 and 2012, high coral recruitment initiated population recovery. Coral recruitment was associated with coral cover, but the relationship differed between two coral genera that are almost exclusively broadcast spawners in Moorea. Acroporids recruited at low densities, and the density of recruits was positively associated with cover of Acropora, whereas pocilloporids recruited at high densities, and densities of their recruits were negatively associated with cover of Pocillopora. Together, our results suggest that associations between adult cover and density of both juveniles and recruits can mediate rapid coral community recovery after large disturbances. The difference between taxa in sign of the relationships between recruit density and coral cover indicate that they reflect contrasting mechanisms with the potential to mediate temporal shifts in taxonomic composition of coral communities.

Competitive interactions between corals and turf algae depend on coral colony form.

PubMed

Swierts, Thomas; Vermeij, Mark Ja

2016-01-01

Turf algae are becoming more abundant on coral reefs worldwide, but their effects on other benthic organisms remain poorly described. To describe the general characteristics of competitive interactions between corals and turf algae, we determined the occurrence and outcomes of coral-turf algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary) on a shallow reef in Vietnam. In total, the amount of turf algal interaction, i.e., the proportion of the coral boundary directly bordering turf algae, was quantified for 1,276 coral colonies belonging to 27 genera and the putative outcome of each interaction was noted. The amount of turf algal interaction and the outcome of these interactions differed predictably among the six growth forms. Encrusting corals interacted most often with turf algae, but also competed most successfully against turf algae. The opposite was observed for branching corals, which rarely interacted with turf algae and rarely won these competitive interactions. Including all other growth forms, a positive relationship was found between the amount of competitive interactions with neighboring turf algae and the percentage of such interaction won by the coral. This growth form dependent ability to outcompete turf algae was not only observed among coral species, but also among different growth forms in morphologically plastic coral genera (Acropora, Favia, Favites, Montastrea, Montipora, Porites) illustrating the general nature of this relationship.

Accessing the genomic effects of naked nanoceria in murine neuronal cells.

PubMed

Lee, Tin-Lap; Raitano, Joan M; Rennert, Owen M; Chan, Siu-Wai; Chan, Wai-Yee

2012-07-01

Cerium oxide nanoparticles (nanoceria) are engineered nanoparticles whose versatility is due to their unique redox properties. We and others have demonstrated that naked nanoceria can act as antioxidants to protect cells against oxidative damage. Although the redox properties may be beneficial, the genome-wide effects of nanoceria on gene transcription and associated biological processes remain elusive. Here we applied a functional genomic approach to examine the genome-wide effects of nanoceria on global gene transcription and cellular functions in mouse neuronal cells. Importantly, we demonstrated that nanoceria induced chemical- and size-specific changes in the murine neuronal cell transcriptome. The nanoceria contributed more than 83% of the population of uniquely altered genes and were associated with a unique spectrum of genes related to neurological disease, cell cycle control, and growth. These observations suggest that an in-depth assessment of potential health effects of naked nanoceria and other naked nanoparticles is both necessary and imminent. Cerium oxide nanoparticles are important antioxidants, with potential applications in neurodegenerative conditions. This team of investigators demonstrated the genomic effects of nanoceria, showing that it induced chemical- and size-specific changes in the murine neuronal cell transcriptome. Published by Elsevier Inc.

State University of New York Stony Brook University Hospital: Selected Expenditure Controls. Report 92-S-66.

ERIC Educational Resources Information Center

New York State Office of the Comptroller, Albany. Div. of Management Audit.

An audit was done of selected expenditure controls at the State University of New York (SUNY) at Stony Brook University Hospital particularly payroll costs and procurement practices. The Hospital reported an operating loss of $24 million in 1992. The audit reviewed Hospital management and staff and applicable policies and procedures as well as…

Spatial refugia mediate juvenile coral survival during coral-predator interactions

NASA Astrophysics Data System (ADS)

Gallagher, Clare; Doropoulos, Christopher

2017-03-01

Coral recruitment and juvenile growth are essential processes for coral population maintenance and recovery. A growing body of research has evaluated the influence of reef microstructure on coral settlement and post-settlement survival, showing that physical refugia enhance recruitment. These studies have evaluated coral recruit morality from competition with macroalgae and indirect predation by grazing organisms, but the impact of direct predation by corallivorous piscine species on juvenile corals and how this interacts with reef microstructure is relatively unknown. This study examined whether refugia provided by micro-crevices enhance juvenile coral survival from corallivory. Juvenile corals from two different functional groups, the slow-growing massive Porites lobata and fast-growing branching Pocillopora damicornis, with average nubbin sizes of 1.4 cm × 0.3 cm and 0.5 cm × 1.0 cm (diameter × height), respectively, were attached to experimental tiles using small (1.44 cm3) and large (8.0 cm3) crevice sizes and were monitored for 29 d on a forereef in Palau. Full crevices (four sided) enhanced coral survival compared to exposed microhabitats in both coral taxa, but crevice size did not alter survival rates. Corallivores targeted recruits within crevices regardless of crevice size; dominant predators included small triggerfish (Balistidae), butterflyfish ( Chaetodon), and wrasse ( Cheilinus). Overall, Pocillopora suffered much higher rates of mortality than Porites. All Pocillopora were consumed by day 8 of the experiment, but mortality was significantly delayed in full crevices compared to exposed and partial crevice (three sided) microhabitats. In contrast, Por. lobata located in all microhabitats survived the entire experiment up to 29 d, with high survival in full (>90%) and partial crevices (70%), but only 28% survival in exposed microhabitats. These findings show the importance of crevices as spatial refugia from predators for juvenile corals and

Two-Laser Interference Visible to the Naked Eye

ERIC Educational Resources Information Center

Kawalec, Tomasz; Bartoszek-Bober, Dobroslawa

2012-01-01

An experimental setup allowing the observation of two-laser interference by the naked eye is described. The key concept is the use of an electronic phase lock between two external cavity diode lasers. The experiment is suitable both for undergraduate and graduate students, mainly in atomic physics laboratories. It gives an opportunity for…

The Laser Teaching Center at Stony Brook

NASA Astrophysics Data System (ADS)

Metcalf, Harold

2010-03-01

Stony Brook's Laser Teaching Center was built more than ten years ago to serve a clientele ranging from high school (HS) students to graduate students. Its construction in a formerly open hallway area was financed by donations from private corporations and foundations, and it was equipped with similar contributions. It provides a working area for laser and optics-related projects, both individual and group. Its daily operations are overseen by a highly-dedicated Ph.D. who is a department employee. It is populated by HS students doing science fair related research, including the major national contests (in which we have many finalists and semifinalists), undergraduates doing extra-credit course projects and other kinds of research activities, graduate students in a special course called ``Optics Rotation,'' and many others who come to use its facilities. All of its denizens benefit enormously by occasional prestigious visitors. Students are drawn from among our undergraduates and graduate students, NSF's WISE program, special HS summer programs, and direct application from the outside. We have an excellent record of placing our HS students in the highest ranking colleges.

NOAA Coral Reef Watch: Decision Support Tools for Coral Reef Managers

NASA Astrophysics Data System (ADS)

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

2010-12-01

A multitude of natural and anthropogenic stressors exert substantial influence on coral reef ecosystems and contribute to bleaching events, slower coral growth, infectious disease outbreaks, and mortality. Satellite-based observations can monitor, at a global scale, environmental conditions that influence both short-term and long-term coral reef ecosystem health. From research to operations, NOAA Coral Reef Watch (CRW) incorporates paleoclimatic, in situ, and satellite-based biogeophysical data to provide near-real-time and forecast information and tools to help managers, researchers, and other stakeholders interpret coral health and stress. CRW has developed an operational, near-real-time product suite that includes sea surface temperature (SST), SST time series data, SST anomaly charts, coral bleaching HotSpots, and Degree Heating Weeks (DHW). Bi-weekly global SST analyses are based on operational nighttime-only SST at 50-km resolution. CRW is working to develop high-resolution products to better address thermal stress on finer scales and is applying climate models to develop seasonal outlooks of coral bleaching. Automated Satellite Bleaching Alerts (SBAs), available at Virtual Stations worldwide, provide the only global early-warning system to notify managers of changing reef environmental conditions. Currently, CRW is collaborating with numerous domestic and international partners to develop new tools to address ocean acidification, infectious diseases of corals, combining light and temperature to detect coral photosystem stress, and other parameters.

Using the Stylophora pistillata genome and cell cultures to understand the mechanism of aragonite precipitation in corals

NASA Astrophysics Data System (ADS)

Mass, T.; Drake, J.; Haramaty, L.; Zelzion, U.; Bhattacharya, D.; Rosenthal, Y.; Falkowski, P. G.

2012-12-01

Atmospheric CO 2 levels are rising rapidly, resulting in a decrease in both oceanic pH, and the carbonate saturation state (Ω). It has been hypothesized that calcifying marine organisms, including reef-building corals, will be affected by the decline of the carbonate saturation state. However, it is still unclear how corals will respond to these changes, as their skeletal formation is biologically mediated and occurs in isolated space rather than directly from seawater. In corals new skeletal material is precipitated in the subcalicoblastic space between the skeleton and the calicoblastic epithelium which, does not exceed a few nanometers and contains the ''calcifying fluid''. The goal of our project is to understand how these fluids respond to changes in the surrounding seawater and in turn affects the biologically mediated calcification mechanisms at the molecular, cellular and tissue levels. While it is generally thought that an organic matrix, which contain a suite of proteins, lipids and poly-saccharides, take part in calcification process, the specific mechanism by which the mineral is precipitated is unknown. The organic matrix composed of two fractions: the soluble organic matrix (SOM) and the insoluble organic matrix (IOM). It is suggested that the IOM plays a role as structural proteins forming a framework for crystal growth whereas the SOM plays a role in nucleation and crystal growth. To address this question we have investigated both the structural framework proteins (Drake et al abstract submitted to the AGU fall meeting) the role of proteins in nucleation and crystal growth (this work). Here, we established cell cultures and sequenced the 458-megabase genome of the stony coral, Stylophora pistillata, using next-generation sequencing technology. This genome contains 21,678 predicted protein-coding genes. Many of the known protein components of invertebrate skeletal matrices are acidic and/or contain repeated sequences. We searched for genes encoding

Competitive interactions between corals and turf algae depend on coral colony form

PubMed Central

Vermeij, Mark JA

2016-01-01

Turf algae are becoming more abundant on coral reefs worldwide, but their effects on other benthic organisms remain poorly described. To describe the general characteristics of competitive interactions between corals and turf algae, we determined the occurrence and outcomes of coral–turf algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary) on a shallow reef in Vietnam. In total, the amount of turf algal interaction, i.e., the proportion of the coral boundary directly bordering turf algae, was quantified for 1,276 coral colonies belonging to 27 genera and the putative outcome of each interaction was noted. The amount of turf algal interaction and the outcome of these interactions differed predictably among the six growth forms. Encrusting corals interacted most often with turf algae, but also competed most successfully against turf algae. The opposite was observed for branching corals, which rarely interacted with turf algae and rarely won these competitive interactions. Including all other growth forms, a positive relationship was found between the amount of competitive interactions with neighboring turf algae and the percentage of such interaction won by the coral. This growth form dependent ability to outcompete turf algae was not only observed among coral species, but also among different growth forms in morphologically plastic coral genera (Acropora, Favia, Favites, Montastrea, Montipora, Porites) illustrating the general nature of this relationship. PMID:27190707

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

NASA Astrophysics Data System (ADS)

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

2016-06-01

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

Naked mole-rat mortality rates defy Gompertzian laws by not increasing with age

PubMed Central

Ruby, J Graham; Smith, Megan

2018-01-01

The longest-lived rodent, the naked mole-rat (Heterocephalus glaber), has a reported maximum lifespan of >30 years and exhibits delayed and/or attenuated age-associated physiological declines. We questioned whether these mouse-sized, eusocial rodents conform to Gompertzian mortality laws by experiencing an exponentially increasing risk of death as they get older. We compiled and analyzed a large compendium of historical naked mole-rat lifespan data with >3000 data points. Kaplan-Meier analyses revealed a substantial portion of the population to have survived at 30 years of age. Moreover, unlike all other mammals studied to date, and regardless of sex or breeding-status, the age-specific hazard of mortality did not increase with age, even at ages 25-fold past their time to reproductive maturity. This absence of hazard increase with age, in defiance of Gompertz’s law, uniquely identifies the naked mole-rat as a non-aging mammal, confirming its status as an exceptional model for biogerontology. PMID:29364116

A coral-on-a-chip microfluidic platform enabling live-imaging microscopy of reef-building corals.

PubMed

Shapiro, Orr H; Kramarsky-Winter, Esti; Gavish, Assaf R; Stocker, Roman; Vardi, Assaf

2016-03-04

Coral reefs, and the unique ecosystems they support, are facing severe threats by human activities and climate change. Our understanding of these threats is hampered by the lack of robust approaches for studying the micro-scale interactions between corals and their environment. Here we present an experimental platform, coral-on-a-chip, combining micropropagation and microfluidics to allow direct microscopic study of live coral polyps. The small and transparent coral micropropagates are ideally suited for live-imaging microscopy, while the microfluidic platform facilitates long-term visualization under controlled environmental conditions. We demonstrate the usefulness of this approach by imaging coral micropropagates at previously unattainable spatio-temporal resolutions, providing new insights into several micro-scale processes including coral calcification, coral-pathogen interaction and the loss of algal symbionts (coral bleaching). Coral-on-a-chip thus provides a powerful method for studying coral physiology in vivo at the micro-scale, opening new vistas in coral biology.

A new rhodamine-based colorimetric chemosensor for naked-eye detection of Cu2 + in aqueous solution

NASA Astrophysics Data System (ADS)

Hu, Yang; Zhang, Jing; Lv, Yuan-Zheng; Huang, Xiao-Huan; Hu, Sheng-li

2016-03-01

A new colorimetric probe 1 based on rhodamine B lactam was developed for naked-eye detection of Cu2 +. The optical feature of 1 for Cu2 + was investigated by UV-vis absorption spectroscopy. Upon the addition of Cu2 +, the 1 displayed a distinct color change from colorless to pink, which can be directly detected by the naked eye. The stoichiometry of 1 to Cu2 + complex was found to be 1:1 and the naked-eye detection limit was determined as low as 2 μM. The results suggest that the probe 1 may provide a convenient method for visual detection of Cu2 + with high sensitivity.

Coral diseases and bleaching on Colombian Caribbean coral reefs.

PubMed

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

2010-05-01

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

Investigation of Effective Material Properties of Stony Meteorites

NASA Technical Reports Server (NTRS)

Agrawal, Parul; Carlozzi, Alex; Bryson, Kathryn

2016-01-01

To assess the threat posed by an asteroid entering Earth's atmosphere, one must predict if, when, and how it fragments during entry. A comprehensive understanding of the Asteroid material properties is needed to achieve this objective. At present, the meteorite material found on Earth are the only objects from an entering asteroid that can be used as representative material and be tested inside a laboratory setting. Therefore, unit cell models are developed to determine the effective material properties of stony meteorites and in turn deduce the properties of asteroids. The unit cell is representative volume that accounts for diverse minerals, porosity, and matrix composition inside a meteorite. The various classes under investigation includes H-class, L-class, and LL-class chondrites. The effective mechanical properties such as Young's Modulus and Poisson's Ratio of the unit cell are calculated by performing several hundreds of Monte-Carlo simulations. Terrestrial analogs such as Basalt and Gabbro are being used to validate the unit cell methodology.

What Do Facts Have to Do with It? Exploring Instructional Emphasis in Stony Brook News Literacy Curriculum

ERIC Educational Resources Information Center

Fleming, Jennifer

2015-01-01

An analytic matrix comprised of multiple media literacy teaching and learning principles is conceptualized to examine a model of news literacy developed by journalism educators at Stony Brook University. The multidimensional analysis indicates that news literacy instructors focus on teaching students how to question and assess the veracity of news…

A coral-on-a-chip microfluidic platform enabling live-imaging microscopy of reef-building corals

PubMed Central

Shapiro, Orr H.; Kramarsky-Winter, Esti; Gavish, Assaf R.; Stocker, Roman; Vardi, Assaf

2016-01-01

Coral reefs, and the unique ecosystems they support, are facing severe threats by human activities and climate change. Our understanding of these threats is hampered by the lack of robust approaches for studying the micro-scale interactions between corals and their environment. Here we present an experimental platform, coral-on-a-chip, combining micropropagation and microfluidics to allow direct microscopic study of live coral polyps. The small and transparent coral micropropagates are ideally suited for live-imaging microscopy, while the microfluidic platform facilitates long-term visualization under controlled environmental conditions. We demonstrate the usefulness of this approach by imaging coral micropropagates at previously unattainable spatio-temporal resolutions, providing new insights into several micro-scale processes including coral calcification, coral–pathogen interaction and the loss of algal symbionts (coral bleaching). Coral-on-a-chip thus provides a powerful method for studying coral physiology in vivo at the micro-scale, opening new vistas in coral biology. PMID:26940983

The cumulative impact of annual coral bleaching can turn some coral species winners into losers.

PubMed

Grottoli, Andréa G; Warner, Mark E; Levas, Stephen J; Aschaffenburg, Matthew D; Schoepf, Verena; McGinley, Michael; Baumann, Justin; Matsui, Yohei

2014-12-01

Mass coral bleaching events caused by elevated seawater temperatures result in extensive coral loss throughout the tropics, and are projected to increase in frequency and severity. If bleaching becomes an annual event later in this century, more than 90% of coral reefs worldwide may be at risk of long-term degradation. While corals can recover from single isolated bleaching and can acclimate to recurring bleaching events that are separated by multiple years, it is currently unknown if and how they will survive and possibly acclimatize to annual coral bleaching. Here, we demonstrate for the first time that annual coral bleaching can dramatically alter thermal tolerance in Caribbean corals. We found that high coral energy reserves and changes in the dominant algal endosymbiont type (Symbiodinium spp.) facilitated rapid acclimation in Porites divaricata, whereas low energy reserves and a lack of algal phenotypic plasticity significantly increased susceptibility in Porites astreoides to bleaching the following year. Phenotypic plasticity in the dominant endosymbiont type of Orbicella faveolata did not prevent repeat bleaching, but may have facilitated rapid recovery. Thus, coral holobiont response to an isolated single bleaching event is not an accurate predictor of its response to bleaching the following year. Rather, the cumulative impact of annual coral bleaching can turn some coral species 'winners' into 'losers', and can also facilitate acclimation and turn some coral species 'losers' into 'winners'. Overall, these findings indicate that cumulative impact of annual coral bleaching could result in some species becoming increasingly susceptible to bleaching and face a long-term decline, while phenotypically plastic coral species will acclimatize and persist. Thus, annual coral bleaching and recovery could contribute to the selective loss of coral diversity as well as the overall decline of coral reefs in the Caribbean. © 2014 John Wiley & Sons Ltd.

A new rhodamine-based colorimetric chemosensor for naked-eye detection of Cu(2+) in aqueous solution.

PubMed

Hu, Yang; Zhang, Jing; Lv, Yuan-Zheng; Huang, Xiao-Huan; Hu, Sheng-Li

2016-03-15

A new colorimetric probe 1 based on rhodamine B lactam was developed for naked-eye detection of Cu(2+). The optical feature of 1 for Cu(2+) was investigated by UV-vis absorption spectroscopy. Upon the addition of Cu(2+), the 1 displayed a distinct color change from colorless to pink, which can be directly detected by the naked eye. The stoichiometry of 1 to Cu(2+) complex was found to be 1:1 and the naked-eye detection limit was determined as low as 2 μM. The results suggest that the probe 1 may provide a convenient method for visual detection of Cu(2+) with high sensitivity. Copyright © 2015 Elsevier B.V. All rights reserved.

A Cyanine Dye Encapsulated Porous Fibrous Mat for Naked-Eye Ammonia Sensing.

PubMed

Ji, Chendong; Ma, Lijing; Yin, Meizhen; Yang, Wantai; Pan, Kai

2016-08-19

Electrospun ultrathin fiber-based sensors are desirable because of their practicality and sensitivity. Ammonia-detection systems are in high demand in different areas, including the industrial and agricultural fields. However, current technologies rely on large and complex instruments that restrict their actual utilization. Herein, we report a flexible naked-eye ammonia sensor, the polylactic acid-cyanine (PLA-Cy) fibrous mat, which was fabricated by blending a carboxyl-functionalized cyanine dye (D1) into electospun PLA porous fibers. The sensing mat was shown to undergo a naked-eye-detectable color change from white to blue upon exposure to ammonia vapor. The mat showed high selectivity to ammonia gas with a detection limit of 3.3 ppm. Aggregated D1 was first encapsulated by PLA and was then ionized by NH3 . These mechanisms were examined by photophysical studies and scanning electron microscopy. The aggregation-deaggregation process of D1 in the PLA-Cy fibrous mat led to the color change. This work provides a facile method for the naked-eye detection of ammonia and a novel strategy for the use of organic dyes in ammonia sensing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Four Cases of Spontaneous Neoplasia in the Naked Mole-Rat (Heterocephalus glaber), A Putative Cancer-Resistant Species.

PubMed

Taylor, Kyle R; Milone, Nicholas A; Rodriguez, Carlos E

2017-01-01

The naked mole-rat (Heterocephalus glaber) is widely acclaimed to be cancer-resistant and of considerable research interest based on a paucity of reports of neoplasia in this species. We have, however, encountered four spontaneous cases of neoplasia and one presumptive case of neoplasia through routine necropsy and biopsy of individuals in a zoo collection of nonhybrid naked mole-rats bred from a single pair. One case each of metastasizing hepatocellular carcinoma, nephroblastoma (Wilms' tumor), and multicentric lymphosarcoma, as well as presumptive esophageal adenocarcinoma (Barrett's esophagus-like) was identified postmortem among 37 nonautolyzed necropsy submissions of naked mole-rats over 1-year-old that were submitted for necropsy between 1998 and August 2015. One incidental case of cutaneous hemangioma was also identified antemortem by skin biopsy from one naked mole-rat examined for trauma. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Micro-topography mediates interactions between corals, algae, and herbivorous fishes on coral reefs

NASA Astrophysics Data System (ADS)

Brandl, S. J.; Hoey, A. S.; Bellwood, D. R.

2014-06-01

Processes occurring during the early life stages of corals are important for the replenishment of coral assemblages and the resilience of coral reefs. However, the factors influencing early life stages of corals are not well understood, and the role of micro-topographic complexity for habitat associations of juvenile corals is largely unexplored. This study investigated the microhabitat distribution patterns of early life stages of corals and a potential macroalgal competitor ( Turbinaria ornata) across two reef zones (reef crest and outer reef flat) on Lizard Island, Great Barrier Reef. In both reef zones, both corals and T. ornata were significantly more abundant in concealed microhabitats than in semi-concealed or open microhabitats (GLMM: P < 0.001). The prevalence of juvenile corals and T. ornata within concealed environments suggests that they might be effective refuges from grazing by herbivorous fishes. The density of juvenile corals was positively related, and density of T. ornata negatively related to the abundance of two groups of herbivorous fishes, pairing rabbitfishes, and surgeonfishes in the genus Zebrasoma (BEST ENV-BIO: r s = 0.72, P < 0.01), which feed in concealed microhabitats. This correlative evidence suggests that crevices may be important for early life stages of both coral and macroalgae, and that a specific suite of crevice-feeding fishes may influence benthic community dynamics in these microhabitats.

Coral lipids and environmental stress.

PubMed

Harriott, V J

1993-04-01

Environmental monitoring of coral reefs is presently limited by difficulties in recognising coral stress, other than by monitoring coral mortality over time. A recent report described an experiment demonstrating that a measured lipid index declined in shaded corals. The technique described might have application in monitoring coral health, with a decline in coral lipid index as an indicator of coral stress. The application of the technique as a practical monitoring tool was tested for two coral species from the Great Barrier Reef. Consistent with the previous results, lipid index for Pocillopora damicornis initially declined over a period of three weeks in corals maintained in filtered seawater in the dark, indicating possible utilization of lipid stored as energy reserves. However, lipid index subsequently rose to near normal levels. In contrast, lipid index of Acropora formosa increased after four weeks in the dark in filtered seawater. The results showed considerable variability in lipid content between samples from the same colony. Results were also found to be dependent on fixation times and sample weight, introducing potential error into the practical application of the technique. The method as described would be unsuitable for monitoring environmental stress in corals, but the search for a practical method to monitor coral health should continue, given its importance in coral reef management.

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

PubMed

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

2017-05-01

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

Brief Report: Stony Brook Guidelines on the Ethics of the Care of People with Autism and Their Families

ERIC Educational Resources Information Center

Post, Stephen G.; Pomeroy, John; Keirns, Carla C.; Cover, Virginia Isaacs; Dorn, Michael Leverett; Boroson, Louis; Boroson, Florence; Coulehan, Anne; Coulehan, Jack; Covell, Kim; Kubasek, Kim; Luchsinger, Elizabeth; Nichols, Shana; Parles, James; Schreiber, Linda; Tetenbaum, Samara P.; Walsh, Rose Ann

2013-01-01

The increased prevalence of autism spectrum disorders (ASD), with associated societal and clinical impacts, calls for a broad community-based dialogue on treatment related ethical and social issues. The Stony Brook Guidelines, based on a community dialogue process with affected individuals, families and professionals, identify and discuss the…

Predicting soil water content at - 33 kPa by pedotransfer functions in stoniness 1 soils in northeast Venezuela.

PubMed

Pineda, M C; Viloria, J; Martínez-Casasnovas, J A; Valera, A; Lobo, D; Timm, L C; Pires, L F; Gabriels, D

2018-02-22

Soil water content is a key property in the study of water available for plants, infiltration, drainage, hydraulic conductivity, irrigation, plant water stress and solute movement. However, its measurement consumes time and, in the case of stony soils, the presence of stones difficult to determinate the water content. An alternative is the use of pedotransfer functions (PTFs), as models to predict these properties from readily available data. The present work shows a comparison of different widely used PTFs to estimate water content at-33 kPa (WR -33kPa ) in high stoniness soils. The work was carried out in the Caramacate River, an area of high interest because the frequent landslides worsen the quality of drinking water. The performance of all evaluated PTFs was compared with a PTF generated for the study area. Results showed that the Urach's PTF presented the best performance in relation to the others and could be used to estimate WR -33kPa in soils of Caramacate River basin. The calculated PTFs had a R 2 of 0.65. This was slightly higher than the R 2 of the Urach's PTF. The inclusion of the rock fragment volume could have the better results. The weak performance of the other PTFs could be related to the fact that the mountain soils of the basin are rich in 2:1 clay and high stoniness, which were not used as independent variables for PTFs to estimate the WR -33kPa .

Registration of a tufted-naked seed upland cotton germplasm

USDA-ARS?s Scientific Manuscript database

A tufted-naked cotton (Gossypium hirsutum L.) mutant, 9023n4t (Reg. No. GP-971, PI 667553) was developed from the cultivar SC 9023 (9023) (PI 590933) through chemical mutagenesis. Germplasm line 9023n4t was developed by the Department of Plant and Soil Science, Texas Tech University, and released in...

The value of naked eye examination of biopsied lymph nodes in the diagnosis of tuberculous lymphadenitis.

PubMed

Bem, C

1996-01-01

Tuberculous lymphadenitis is common in Central Africa, where diagnosis by histological examination of a biopsied node is often delayed. In the present study, the naked eye appearance of the cut surface of 306 consecutive biopsied lymph nodes was compared with the histological diagnosis. One hundred and eight-eight nodes showed tuberculosis on histology (including two with coexisting second pathology). One hundred and forty-eight (79%) cases of tuberculous lymphadenitis (including both with coexisting second pathology) showed noncaseating tuberculomata or caseation visible on naked eye examination. Such signs were not seen in other nodes. Other signs were seen in another 18 (10%) tuberculous nodes. It is concluded that naked eye examination of nodes provides useful information for the diagnosis of tuberculous lymphadenitis, pending confirmation by histology.

Cryobiology of coral fragments.

PubMed

Hagedorn, Mary; Farrell, Ann; Carter, Virginia L

2013-02-01

Around the world, coral reefs are dying due to human influences, and saving habitat alone may not stop this destruction. This investigation focused on the biological processes that will provide the first steps in understanding the cryobiology of whole coral fragments. Coral fragments are a partnership of coral tissue and endosymbiotic algae, Symbiodinium sp., commonly called zooxanthellae. These data reflected their separate sensitivities to chilling and a cryoprotectant (dimethyl sulfoxide) for the coral Pocillopora damicornis, as measured by tissue loss and Pulse Amplitude Modulated fluorometry 3weeks post-treatment. Five cryoprotectant treatments maintained the viability of the coral tissue and zooxanthellae at control values (1M dimethyl sulfoxide at 1.0, 1.5 and 2.0h exposures, and 1.5M dimethyl sulfoxide at 1.0 and 1.5h exposures, P>0.05, ANOVA), whereas 2M concentrations did not (P<0.05, ANOVA). A seasonal response to chilling was observed in the coral tissue, but not in the zooxanthellae. During the winter when the fragments were chilled, the coral tissue remained relatively intact (∼25% loss) post-treatment, but the zooxanthellae numbers in the tissue declined after 5min of chilling (P<0.05, ANOVA). However, in the late spring, coral tissue (∼75% loss) and zooxanthellae numbers declined in response to chilling alone (P<0.05, ANOVA). When a cryoprotectant (1M dimethyl sulfoxide) was used in concert with chilling it protected the coral against tissue loss after 45min of cryoprotectant exposure (P>0.05, ANOVA), but it did not protect against the loss of zooxanthellae (P<0.05, ANOVA). The zooxanthellae are the most sensitive element in the coral fragment complex and future cryopreservation protocols must be guided by their greater sensitivity. Copyright © 2012 Elsevier Inc. All rights reserved.

Quantum Backreaction on Three-Dimensional Black Holes and Naked Singularities.

PubMed

Casals, Marc; Fabbri, Alessandro; Martínez, Cristián; Zanelli, Jorge

2017-03-31

We analytically investigate backreaction by a quantum scalar field on two rotating Bañados-Teitelboim-Zanelli (BTZ) geometries: that of a black hole and that of a naked singularity. In the former case, we explore the quantum effects on various regions of relevance for a rotating black hole space-time. We find that the quantum effects lead to a growth of both the event horizon and the radius of the ergosphere, and to a reduction of the angular velocity, compared to the unperturbed values. Furthermore, they give rise to the formation of a curvature singularity at the Cauchy horizon and show no evidence of the appearance of a superradiant instability. In the case of a naked singularity, we find that quantum effects lead to the formation of a horizon that shields it, thus supporting evidence for the rôle of quantum mechanics as a cosmic censor in nature.

Enrichment Programs and Professional Development in the Geosciences: Best Practices and Models (OEDG Research Report, Stony Brook University)

ERIC Educational Resources Information Center

Gafney, Leo

2017-01-01

This report is based on several evaluations of NSF-funded geoscience projects at Stony Brook University on Long Island, NY. The report reviews the status of K-12 geoscience education, identifying challenges posed by the Next Generation Science Standards (NGSS), the experiences of university faculty engaged in teacher preparation, state…

Sex-specific but not sexually explicit: pupillary responses to dressed and naked adults.

PubMed

Attard-Johnson, Janice; Bindemann, Markus

2017-05-01

Dilation of the pupils is an indicator of an observer's sexual interest in other people, but it remains unresolved whether this response is strengthened or diminished by sexually explicit material. To address this question, this study compared pupillary responses of heterosexual men and women to naked and dressed portraits of male and female adult film actors. Pupillary responses corresponded with observers' self-reported sexual orientation, such that dilation occurred during the viewing of opposite-sex people, but were comparable for naked and dressed targets. These findings indicate that pupillary responses provide a sex-specific measure, but are not sensitive to sexually explicit content.

RNA Sequencing Reveals Differential Expression of Mitochondrial and Oxidation Reduction Genes in the Long-Lived Naked Mole-Rat When Compared to Mice

PubMed Central

Holmes, Andrew; Szafranski, Karol; Faulkes, Chris G.; Coen, Clive W.; Buffenstein, Rochelle; Platzer, Matthias; de Magalhães, João Pedro; Church, George M.

2011-01-01

The naked mole-rat (Heterocephalus glaber) is a long-lived, cancer resistant rodent and there is a great interest in identifying the adaptations responsible for these and other of its unique traits. We employed RNA sequencing to compare liver gene expression profiles between naked mole-rats and wild-derived mice. Our results indicate that genes associated with oxidoreduction and mitochondria were expressed at higher relative levels in naked mole-rats. The largest effect is nearly 300-fold higher expression of epithelial cell adhesion molecule (Epcam), a tumour-associated protein. Also of interest are the protease inhibitor, alpha2-macroglobulin (A2m), and the mitochondrial complex II subunit Sdhc, both ageing-related genes found strongly over-expressed in the naked mole-rat. These results hint at possible candidates for specifying species differences in ageing and cancer, and in particular suggest complex alterations in mitochondrial and oxidation reduction pathways in the naked mole-rat. Our differential gene expression analysis obviated the need for a reference naked mole-rat genome by employing a combination of Illumina/Solexa and 454 platforms for transcriptome sequencing and assembling transcriptome contigs of the non-sequenced species. Overall, our work provides new research foci and methods for studying the naked mole-rat's fascinating characteristics. PMID:22073188

The Keeling Curve and The Coral Reef Mosaic Project - Introducing the Realities of Climate Change to Educators and Scholars using Mosaic Arts.

NASA Astrophysics Data System (ADS)

Lueker, T.; Chinn, P. W. U.

2014-12-01

In May 2013, The, record of atmospheric CO2 at Mauna Loa, popularly known as "The Keeling Curve" reached 400 ppm for the first time in human history. Among the most sobering consequences of rising CO2 is Ocean Acidification, caused when the excess CO2 emitted from the burning of fossil fuels is absorbed by the surface oceans. The resulting reduction in pH harms stony corals (Scleractinia), and many other calcareous organisms. If civilization continues along the current trajectory of fossil fuel emissions, most coral reef ecosystems are expected to suffer extreme stress or mortality within the lifetime of the next generation. "If we do not reverse current trends in carbon dioxide emissions soon, we will cause the biggest and most rapid change in ocean chemistry since the extinction of the dinosaurs." (www.seaweb.org/getinvolved/oceanvoices/KenCaldeira.php). This looming tragedy is topical among marine scientists, but less appreciated or unknown to the general public, particularly among communities in the tropics where impacts to coral reef ecosystems will be severe. The Coral Reef Mosaic Project grew from my experiences leading education outreach in local schools. Making mosaics is an engaging way to enlighten educators and scholars on the pressing issues of climate change. When taking part in a mural project, students find mosaic art is a fun and rewarding experience that results in a beautiful depiction of a coral reef. Students explore the ecosystem diversity of coral reef inhabitants as they design the mural and piece together a representative environment. They work together as a team to learn the mosaic techniques and then build their own chosen creatures to inhabit the reef. The result is a beautiful and lasting mural for their school or community that provides an important message for the future. In a cooperative project with Dr. Pauline Chin at UH Manoa we traveled to Hawaii to train teachers on the Big Island in the art of mosaic and to convey the

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

NASA Astrophysics Data System (ADS)

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

2015-12-01

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

Examination of the cervix with the naked eye using acetic acid test.

PubMed

Ottaviano, M; La Torre, P

1982-05-15

Examination of the cervix was carried out on 2,400 patients, by use of acetic acid test with the naked eye and the colposcope. The physiologic transformation zone was clearly identified both with the naked eye and the colposcope in 1,568 of 1,594 (99%) cases. Colposcopic examination was unsatisfactory in 108 of the 264 (41%) patients in whom the cervix was completely covered by normal squamous epithelium. An atypical transformation zone (ATZ) was identified with the naked eye as white epithelium in 98.4% and as "suspicious" in 1.6% of 312 colposcopically controlled cases. An unsatisfactory colposcopic examination occurred in 39 of the 312 (12.5%) patients with an ATZ. Final histologic diagnosis for 312 ATZs was benign lesion in 169 of 312 (54.2%), cervical intraepithelial neoplasia (CIN) grades 1 and 2 in 81 of 312 (26%), grade 3 CIN in 56 of 312 (17.9%), and preclinical invasive carcinoma in 6 of 312 (1.9%). The detection of intraepithelial or preclinical invasive cervical neoplasias should not depend on the possession of a colposcope. On the other hand, the use of a colposcope is essential for the selection of CIN that can be treated with ultraconservative therapy or with colposcopically directed conization.

Gis-Based Crop Support System For Common Oatand Naked Oat in China

NASA Astrophysics Data System (ADS)

Wan, Fan; Wang, Zhen; Li, Fengmin; Cao, Huhua; Sun, Guojun

The identification of the suitable areas for common oat (Avena sativa L.) and naked oat (Avena nuda L.) in China using Multi-Criteria Evaluation (MCE) approach based on GIS is presented in the current article. Climate, topography, soil, land use and oat variety databases were created. Relevant criteria,suitability levels and their weights for each factor were defined. Then the criteria maps were obtained and turned into the MCE process, and suitability maps for common oat and naked oat were created. The land use and the suitability maps were crossed to identify the suitable areas for each crop. The results identified 397,720 km2 of suitable areas for common oats of forage purpose distributed in 744 counties in 17 provinces, and 556,232 km2 of suitable areas for naked oats of grain purpose distributed in 779 counties in 19 provinces. This result is in accordance with the distribution of farmingpastoral ecozones located in semi-arid regions of northern China. The mapped areas can help define the working limits and serve as indicative zones for oat in China. The created databases, mapped results, interface of expert system and relevant hardware facilities could construct a complete crop support system for oats.

Lipoxygenase-allene oxide synthase pathway in octocoral thermal stress response

NASA Astrophysics Data System (ADS)

Lõhelaid, H.; Teder, T.; Samel, N.

2015-03-01

Marine ecosystems are sensitive to elevated seawater temperature, with stony corals serving as model organisms for temperature-imposed declines in population viability and diversity. Several stress markers, including heat shock proteins, have been used for the detection and prediction of stress responses in stony corals. However, the stress indicators in soft corals remain elusive. In higher animals and plants, oxylipins synthesized by fatty acid di- and monooxygenases contribute to stress-induced signaling; however, the role of eicosanoid pathways in corals remains unclear. The eicosanoid gene specific to corals encodes for a natural fusion protein of allene oxide synthase and lipoxygenase ( AOS- LOX). In this work, using the easily cultivated soft coral Capnella imbricata as the stress response model, we monitored the expression of the AOS-LOX and the formation of arachidonic acid metabolites in response to an acute rise in water temperature. Gene expression profiles of two 70 kDa heat shock proteins ( Hsps: Hsp70 and Grp78) were used as a positive control for the stress response. In comparison with normal seawater temperature (23 °C), AOS- LOXa and Hsps were all up-regulated after modest (28 °C) and severe (31 °C) temperature elevation. While the up-regulation of AOS- LOXa and Grp78 was more sensitive to moderate temperature changes, Hsp70s were more responsive to severe heat shock. Concurrently, endogenous and exogenous AOS-LOXa-derived eicosanoids were up-regulated. Thus, together with the up-regulation of AOS- LOX by other abiotic and biotic stress stimuli, these data implicate AOS-LOX as part of the general stress response pathway in corals.

Phage therapy for Florida corals?

USGS Publications Warehouse

Kellogg, Christina A.

2007-01-01

Coral disease is a major cause of reef decline in the Florida Keys. Bacterium has been defined as the most common pathogen (disease-causing organism). Although much is being done to catalog coral diseases, map their locations, determine the causes of disease, or measure the rates of coral demise, very little research has been directed toward actually preventing or eliminating the diseases affecting coral and coral reef decline.

Cryptic effects of habitat declines: coral-associated fishes avoid coral-seaweed interactions due to visual and chemical cues

PubMed Central

Brooker, Rohan M.; Brandl, Simon J.; Dixson, Danielle L.

2016-01-01

Seaweed-dominated coral reefs are becoming increasingly common as environmental conditions shift away from those required by corals and toward those ideal for rampant seaweed growth. How coral-associated organisms respond to seaweed will not only impact their fate following environmental change but potentially also the trajectories of the coral communities on which they rely. However, behavioral responses by coral-associated organisms to seaweeds are poorly understood. This study examined interactions between a guild of obligate and opportunistic coral-feeding butterflyfishes (Chaetodontidae) and scleractinian corals to determine whether fishes continue to interact with corals in contact with seaweed or if they are avoided. Under natural conditions, all species interacted almost exclusively with seaweed-free corals. In a controlled patch reef experiment, fishes avoided corals in physical contact with seaweed, irrespective of dietary preferences. When visual seaweed cues were removed, butterflyfish continued to avoid corals that had been in contact with the allelopathic Galaxaura filamentosa, suggesting that chemical cues produced by coral-seaweed interactions are repellent. These findings suggest that, due to deleterious visual and chemical cues produced by coral-seaweed interactions, coral-associated organisms may struggle to locate resources as seaweed-free corals decline in abundance. PMID:26725835

Cryptic effects of habitat declines: coral-associated fishes avoid coral-seaweed interactions due to visual and chemical cues.

PubMed

Brooker, Rohan M; Brandl, Simon J; Dixson, Danielle L

2016-01-04

Seaweed-dominated coral reefs are becoming increasingly common as environmental conditions shift away from those required by corals and toward those ideal for rampant seaweed growth. How coral-associated organisms respond to seaweed will not only impact their fate following environmental change but potentially also the trajectories of the coral communities on which they rely. However, behavioral responses by coral-associated organisms to seaweeds are poorly understood. This study examined interactions between a guild of obligate and opportunistic coral-feeding butterflyfishes (Chaetodontidae) and scleractinian corals to determine whether fishes continue to interact with corals in contact with seaweed or if they are avoided. Under natural conditions, all species interacted almost exclusively with seaweed-free corals. In a controlled patch reef experiment, fishes avoided corals in physical contact with seaweed, irrespective of dietary preferences. When visual seaweed cues were removed, butterflyfish continued to avoid corals that had been in contact with the allelopathic Galaxaura filamentosa, suggesting that chemical cues produced by coral-seaweed interactions are repellent. These findings suggest that, due to deleterious visual and chemical cues produced by coral-seaweed interactions, coral-associated organisms may struggle to locate resources as seaweed-free corals decline in abundance.

Sex-specific but not sexually explicit: pupillary responses to dressed and naked adults

PubMed Central

Bindemann, Markus

2017-01-01

Dilation of the pupils is an indicator of an observer's sexual interest in other people, but it remains unresolved whether this response is strengthened or diminished by sexually explicit material. To address this question, this study compared pupillary responses of heterosexual men and women to naked and dressed portraits of male and female adult film actors. Pupillary responses corresponded with observers' self-reported sexual orientation, such that dilation occurred during the viewing of opposite-sex people, but were comparable for naked and dressed targets. These findings indicate that pupillary responses provide a sex-specific measure, but are not sensitive to sexually explicit content. PMID:28572991

Elemental composition analysis of stony meteorites discovered in Phitsanulok, Thailand

NASA Astrophysics Data System (ADS)

Loylip, T.; Wannawichian, S.

2017-09-01

A meteorite is a fragment of pure stone, iron or the mixture of stony-iron. The falling of meteorites into Earth’s surface is part of Earth’s accretion process from dust and rocks in our solar system. When these fragments come close enough to the Earth to be attracted by its gravity, they may fall into the Earth. Following the detection of objects that fall from the sky onto a home in Phitsanulok in June 27, the meteorites were analyzed by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS) instruments. The results from SEM/EDS analysis show that the meteorites are mainly composed of Fe-Ni and Fe-s. The meteorite is Achondrite, a class of meteorite which does not contain Chondrule. The meteorites in this work are thought to be part of a large asteroid.

Hurricanes and coral bleaching linked to changes in coral recruitment in Tobago.

PubMed

Mallela, J; Crabbe, M J C

2009-10-01

Knowledge of coral recruitment patterns helps us understand how reefs react following major disturbances and provides us with an early warning system for predicting future reef health problems. We have reconstructed and interpreted historical and modern-day recruitment patterns, using a combination of growth modelling and in situ recruitment experiments, in order to understand how hurricanes, storms and bleaching events have influenced coral recruitment on the Caribbean coastline of Tobago. Whilst Tobago does not lie within the main hurricane belt results indicate that regional hurricane events negatively impact coral recruitment patterns in the Southern Caribbean. In years following hurricanes, tropical storms and bleaching events, coral recruitment was reduced when compared to normal years (p=0.016). Following Hurricane Ivan in 2004 and the 2005-2006 bleaching event, coral recruitment was markedly limited with only 2% (n=6) of colonies estimated to have recruited during 2006 and 2007. Our experimental results indicate that despite multiple large-scale disturbances corals are still recruiting on Tobago's marginal reef systems, albeit in low numbers.

Spectral classifying base on color of live corals and dead corals covered with algae

NASA Astrophysics Data System (ADS)

Nurdin, Nurjannah; Komatsu, Teruhisa; Barille, Laurent; Akbar, A. S. M.; Sawayama, Shuhei; Fitrah, Muh. Nur; Prasyad, Hermansyah

2016-05-01

Pigments in the host tissues of corals can make a significant contribution to their spectral signature and can affect their apparent color as perceived by a human observer. The aim of this study is classifying the spectral reflectance of corals base on different color. It is expected that they can be used as references in discriminating between live corals, dead coral covered with algae Spectral reflectance data was collected in three small islands, Spermonde Archipelago, Indonesia by using a hyperspectral radiometer underwater. First and second derivative analysis resolved the wavelength locations of dominant features contributing to reflectance in corals and support the distinct differences in spectra among colour existed. Spectral derivative analysis was used to determine the specific wavelength regions ideal for remote identification of substrate type. The analysis results shown that yellow, green, brown and violet live corals are spectrally separable from each other, but they are similar with dead coral covered with algae spectral.

Effect of hypoxia on metabolic rate, core body temperature, and c-fos expression in the naked mole rat.

PubMed

Nathaniel, Thomas I; Otukonyong, Effiong; Abdellatif, Ahmed; Soyinka, Julius O

2012-10-01

Recent investigations of hypoxia physiology in the naked mole rat have opened up an interesting line of research into the basic physiological and genomic alterations that accompany hypoxia survival. The extent to which such findings connect the effect of hypoxia to metabolic rate (O₂ consumption), core body temperature (Tb), and transcripts encoding the immediate early gene product (such as c-fos) under a constant ambient temperature (Ta) is not well known. We investigated this issue in the current study. Our first sets of experiments measured Tb and metabolic rates during exposure of naked mole rats to hypoxia over a constant Ta. Hypoxia significantly decreased metabolic rates in the naked mole rat. Although core Tb also decreased during hypoxia, the effect of hypoxia in suppressing core Tb was not significant. The second series of experiments revealed that c-fos protein and mRNA expression in the hippocampus neurons (CA1) increased in naked mole rats that were repeatedly exposed to 3% O₂ for 60 min per day for 5 days when compared to normoxia. Our findings provide evidence for the up-regulation of c-fos and suppression of metabolic rate in hypoxia tolerating naked mole rats under constant ambient temperature. Metabolic suppression and c-fos upregulation constitute part of the physiological complex associated with adaptation to hypoxia. Published by Elsevier Ltd.

Ecological Complexity of Coral Recruitment Processes: Effects of Invertebrate Herbivores on Coral Recruitment and Growth Depends Upon Substratum Properties and Coral Species

PubMed Central

Davies, Sarah W.; Matz, Mikhail V.; Vize, Peter D.

2013-01-01

Background The transition from planktonic planula to sessile adult corals occurs at low frequencies and post settlement mortality is extremely high. Herbivores promote settlement by reducing algal competition. This study investigates whether invertebrate herbivory might be modulated by other ecological factors such as substrata variations and coral species identity. Methodology/Principal Findings The experiment was conducted at the Flower Garden Banks, one of the few Atlantic reefs not experiencing considerable degradation. Tiles of differing texture and orientation were kept in bins surrounded by reef (24 m). Controls contained no herbivores while treatment bins contained urchins (Diadema antillarum) or herbivorous gastropods (Cerithium litteratum). Juvenile corals settling naturally were monitored by photography for 14 months to evaluate the effects of invertebrate herbivory and substratum properties. Herbivory reduced algae cover in urchin treatments. Two genera of brooding coral juveniles were observed, Agaricia and Porites, both of which are common but not dominant on adjacent reef. No broadcast spawning corals were observed on tiles. Overall, juveniles were more abundant in urchin treatments and on vertical, rough textured surfaces. Although more abundant, Agaricia juveniles were smaller in urchin treatments, presumably due to destructive overgrazing. Still, Agaricia growth increased with herbivory and substrata texture-orientation interactions were observed with reduced growth on rough tiles in control treatments and increased growth on vertical tiles in herbivore treatments. In contrast to Agaricia, Porites juveniles were larger on horizontal tiles, irrespective of herbivore treatment. Mortality was affected by substrata orientation with vertical surfaces increasing coral survival. Conclusions/Significance We further substantiate that invertebrate herbivores play major roles in early settlement processes of corals and highlight the need for deeper

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.

CORAL Server and CORAL Server Proxy: Scalable Access to Relational Databases from CORAL Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valassi, A.; /CERN; Bartoldus, R.

The CORAL software is widely used at CERN by the LHC experiments to access the data they store on relational databases, such as Oracle. Two new components have recently been added to implement a model involving a middle tier 'CORAL server' deployed close to the database and a tree of 'CORAL server proxies', providing data caching and multiplexing, deployed close to the client. A first implementation of the two new components, released in the summer 2009, is now deployed in the ATLAS online system to read the data needed by the High Level Trigger, allowing the configuration of a farmmore » of several thousand processes. This paper reviews the architecture of the software, its development status and its usage in ATLAS.« less

Big Data Approaches To Coral-Microbe Symbiosis

NASA Astrophysics Data System (ADS)

Zaneveld, J.; Pollock, F. J.; McMinds, R.; Smith, S.; Payet, J.; Hanna, B.; Welsh, R.; Foster, A.; Ohdera, A.; Shantz, A. A.; Burkepile, D. E.; Maynard, J. A.; Medina, M.; Vega Thurber, R.

2016-02-01

Coral reefs face increasing challenges worldwide, threatened by overfishing and nutrient pollution, which drive growth of algal competitors of corals, and periods of extreme temperature, which drive mass coral bleaching. I will discuss two projects that examine how coral's complex relationships with microorganisms affect the response of coral colonies and coral species to environmental challenge. Microbiological studies have documented key roles for coral's microbial symbionts in energy harvest and defense against pathogens. However, the evolutionary history of corals and their microbes is little studied. As part of the Global Coral Microbiome Project, we are characterizing bacterial, archaeal, fungal, and Symbiodinium diversity across >1400 DNA samples from all major groups of corals, collected from 15 locations worldwide. This collection will allow us to ask how coral- microbe associations evolved over evolutionary time, and to determine whether microbial symbiosis helps predict the relative vulnerability of certain coral species to environmental stress. In the second project, we experimentally characterized how the long-term effects of human impacts such as overfishing and nutrient pollution influence coral-microbe symbiosis. We conducted a three-year field experiment in the Florida Keys applying nutrient pollution or simulated overfishing to reef plots, and traced the effects on reef communities, coral microbiomes, and coral health. The results show that extremes of temperature and algal competition destabilize coral microbiomes, increasing pathogen blooms, coral disease, and coral death. Surprisingly, these local stressors interacted strongly with thermal stress: the greatest microbiome disruption, and >80% of coral mortality happened in the hottest periods. Thus, overfishing and nutrient pollution may interact with increased climate-driven episodes of sub-bleaching thermal stress to increase coral mortality by disrupt reef communities down to microbial scales.

Media Literacy, News Literacy, or News Appreciation? A Case Study of the News Literacy Program at Stony Brook University

ERIC Educational Resources Information Center

Fleming, Jennifer

2014-01-01

This case study provides practical and theoretical insights into the Stony Brook news literacy program, which is one of the most ambitious and well-funded curricular experiments in modern journalism education and media literacy. Analysis of document, interview, and observation data indicates that news literacy educators sought to teach students…

Use of a fluorescent membrane probe to identify zooxanthellae in hospite among dissociated endoderm cell culture from coral.

PubMed

Chen, C-S; Lin, H-P; Yeh, C-C; Fang, L-S

2005-12-01

Preparation of homogeneous endoderm cells and culture is a prerequisite to understanding the cellular and molecular mechanism of endosymbiosis in the cnidarian-dinoflagellate association. During the cell isolation from the stony coral Euphyllia glabrescens, various amounts of symbiotic endoderm cells were found to release their symbionts (Symbiodinium spp., or zooxanthellae in generic usage) into the culture. Due to the bulky occupation by zooxanthellae inside the endoderm cell, the symbiotic endoderm cells, or zooxanthellae in hospite, are difficult to be distinguished from released zooxanthellae by microscopic examination. We now report a method for this identification using a fluorescent analogue of sphingomyelin, N-[5-(5,7-dimethyl boron dipyrromethene difluoride)-1-pentanoyl]-D-erythro-sphingosylphosphorylcholine (C(5)-DMB-SM). Incubation of symbiotic endoderm cells with C(5)-DMB-SM-defatted bovine serum albumin (DF-BSA) complex results in bright fluorescent membrane staining. Nevertheless, the membrane staining of free-living or released zooxanthellae by this complex is significantly decreased or even diminished. This method has provided a fast and reliable assay to identify symbiotic endoderm cells and will greatly accelerate the progress of endosymbiosis research.

Back to basics: naked-eye astronomical observation

NASA Astrophysics Data System (ADS)

Barclay, Charles

2003-09-01

For pupils of both sexes and all ages from about six upwards, the subject of Astronomy holds many fascinations - the rapid changes in knowledge, the large resource of available IT packages and above all the beautiful pictures from Hubble and the large Earth-based telescopes. This article, however, stresses the excitement and importance of naked-eye (unaided) first-hand observation, where light pollution allows, and suggests some techniques that may be used to enthuse and introduce youngsters to the glory of the night sky without recourse to computer screens.

The secret lives of corals: Climate records from coral chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beck, J.W.; Smoker, M.; Burr, G.

1995-12-01

Corals can provide archives of a diverse suite of information about the ocean surface mixed layer, including records of ocean surface temperature (via coral Sr/Ca or U/Ca measurements), salinity (via {gamma}{sup 18}O measurements), biologic activity (via {gamma}{sup 13}C measurements), and ocean/atmosphere CO{sub 2} exchange rates (via {sup 14}C/{sup 12}C measurements). Recently, it has been shown that corals record evidence of large seasonal oscillations in {sup 14}C concentration of the ocean surface mixed layer, and that such oscillations are modulated by ENSO. These oscillations are related to seasonal changes in the surface wind velocity field, changes in the patterns of regionalmore » upwelling, as well as seasonal changes in the strength of the thermocline. High frequency AMS {sup 14}C analyses of corals shows that ENSO events can dramatically diminish the annual range in ocean mixed layer {sup 14}C concentration in this region. Our work on a coral from Vanuatu in the western equatorial Pacific also documents large seasonal changes in {sup 14}C concentration (3-5%) as well as ENSO modulation of these variations during the 82-83 ENSO event.« less

Corals from Space

NASA Technical Reports Server (NTRS)

Patzert, William C.

1999-01-01

The goal of this research is to monitor the health and vigor of coral reef ecosystems, and their sensitivity to natural and anthropogenic climate changes. To achieve these lofty goals, this research is investigating the feasibility of using spaceborne high-resolution spectrometers (on the US Landsat, French Systeme Probatoire pour l'Observation de la Terre [SPOT] and/or the Indian Resources Satellite [IRS 1C & 1D] spacecraft) to first map the aerial extent of coral reef systems, and second separate the amount of particular corals. If this is successful, we could potentially provide a quantum leap in our understanding of coral reef systems, as well as provide much needed baseline data to measure future changes in global coral reef ecosystems. In collaboration with Tomas Tomascik, Yann Morel, and other colleagues, a series of experiments were planned to coordinate in situ coral observations, high-resolution spaceborne imagery (from Landsat, SPOT, and, possibly, IRS IC spacecraft), and NASA Space Shuttle photographs and digital images. Our eventual goal is to develop "coral health algorithms" that can be used to assess time series of imagery collected from satellite sensors (Landsat since 1972, SPOT since 1986) in concert with in situ observations. The bad news from last year was that from 1997 to mid- 1998, the extreme cloudiness over southeast Asia due to prolonged smoke from El Nino-related fires and the economic chaos in this region frustrated both our space and reef-based data collection activities. When this volatile situation stabilizes, we will restart these activities. The good news was that in collaboration with Al Strong at the National Oceanic and Atmospheric Administration (NOAA) we had an exciting year operationally using the NOAA's Advanced Very High Resolution Radiometer sensor derived sea surface temperature products to warn of coral "bleaching" at many locations throughout the tropics. Data from NOAA's satellites showed that during the El Nino of

Polyphyly and hidden species among Hawaiʻi’s dominant mesophotic coral genera, Leptoseris and Pavona (Scleractinia: Agariciidae)

PubMed Central

Forsman, Zac H.; Toonen, Robert J.; Leicht, Sarah J.; Kahng, Samuel E.

2013-01-01

Widespread polyphyly in stony corals (order Scleractinia) has prompted efforts to revise their systematics through approaches that integrate molecular and micromorphological evidence. To date, these approaches have not been comprehensively applied to the dominant genera in mesophotic coral ecosystems (MCEs) because several species in these genera occur primarily at depths that are poorly explored and from which sample collections are limited. This study is the first integrated morphological and molecular systematic analysis of the genera Leptoseris and Pavona to examine material both from shallow-water reefs (<30 m) and from mid- to lower-MCEs (>60 m). Skeletal and tissue samples were collected throughout the Hawaiian Archipelago between 2–127 m. A novel mitochondrial marker (cox1-1-rRNA intron) was sequenced for 70 colonies, and the micromorphologies of 94 skeletons, plus selected type material, were analyzed. The cox1-1-rRNA intron resolved 8 clades, yet Leptoseris and Pavona were polyphyletic. Skeletal micromorphology, especially costal ornamentation, showed strong correspondence and discrete differences between mitochondrial groups. One putative new Leptoseris species was identified and the global depth range of the genus Pavona was extended to 89 m, suggesting that the diversity of mesophotic scleractinians has been underestimated. Examination of species’ depth distributions revealed a pattern of depth zonation: Species common in shallow-water were absent or rare >40 m, whereas others occurred only >60 m. These patterns emphasize the importance of integrated systematic analyses and more comprehensive sampling by depth in assessing the connectivity and diversity of MCEs. PMID:24032091

The perception of (naked only) bodies and faceless heads relies on holistic processing: Evidence from the inversion effect.

PubMed

Bonemei, Rob; Costantino, Andrea I; Battistel, Ilenia; Rivolta, Davide

2018-05-01

Faces and bodies are more difficult to perceive when presented inverted than when presented upright (i.e., stimulus inversion effect), an effect that has been attributed to the disruption of holistic processing. The features that can trigger holistic processing in faces and bodies, however, still remain elusive. In this study, using a sequential matching task, we tested whether stimulus inversion affects various categories of visual stimuli: faces, faceless heads, faceless heads in body context, headless bodies naked, whole bodies naked, headless bodies clothed, and whole bodies clothed. Both accuracy and inversion efficiency score results show inversion effects for all categories but for clothed bodies (with and without heads). In addition, the magnitude of the inversion effect for face, naked body, and faceless heads was similar. Our findings demonstrate that the perception of faces, faceless heads, and naked bodies relies on holistic processing. Clothed bodies (with and without heads), on the other side, may trigger clothes-sensitive rather than body-sensitive perceptual mechanisms. © 2017 The British Psychological Society.

Phage-mediated counting by the naked eye of miRNA molecules at attomolar concentrations in a Petri dish.

PubMed

Zhou, Xin; Cao, Peng; Zhu, Ye; Lu, Wuguang; Gu, Ning; Mao, Chuanbin

2015-10-01

The ability to count biomolecules such as cancer-biomarker miRNAs with the naked eye is seemingly impossible in molecular diagnostics. Here, we show an ultrasensitive naked-eye-counting strategy for quantifying miRNAs by employing T7 phage-a bacteria-specific virus nanoparticle-as a surrogate. The phage is genetically engineered to become fluorescent and capable of binding a miRNA-capturing gold nanoparticle (GNP) in a one-to-one manner. Target miRNAs crosslink the resultant phage-GNP couple and miRNA-capturing magnetic microparticles, forming a sandwich complex containing equimolar phage and miRNA. The phage is then released from the complex and developed into one macroscopic fluorescent plaque in a Petri dish by plating it in a host bacterial medium. Counting the plaques by the naked eye enables the quantification of miRNAs with detection limits of ∼3 and ∼5 aM for single-target and two-target miRNAs, respectively. This approach offers ultrasensitive and convenient quantification of disease biomarkers by the naked eye.

Phage-mediated counting by the naked eye of miRNA molecules at attomolar concentrations in a Petri dish

NASA Astrophysics Data System (ADS)

Zhou, Xin; Cao, Peng; Zhu, Ye; Lu, Wuguang; Gu, Ning; Mao, Chuanbin

2015-10-01

The ability to count biomolecules such as cancer-biomarker miRNAs with the naked eye is seemingly impossible in molecular diagnostics. Here, we show an ultrasensitive naked-eye-counting strategy for quantifying miRNAs by employing T7 phage--a bacteria-specific virus nanoparticle--as a surrogate. The phage is genetically engineered to become fluorescent and capable of binding a miRNA-capturing gold nanoparticle (GNP) in a one-to-one manner. Target miRNAs crosslink the resultant phage-GNP couple and miRNA-capturing magnetic microparticles, forming a sandwich complex containing equimolar phage and miRNA. The phage is then released from the complex and developed into one macroscopic fluorescent plaque in a Petri dish by plating it in a host bacterial medium. Counting the plaques by the naked eye enables the quantification of miRNAs with detection limits of ~3 and ~5 aM for single-target and two-target miRNAs, respectively. This approach offers ultrasensitive and convenient quantification of disease biomarkers by the naked eye.

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

EPA Science Inventory

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

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

PubMed

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

2016-01-07

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

Identification and prevalence of coral diseases on three Western Indian Ocean coral reefs.

PubMed

Séré, Mathieu G; Chabanet, Pascale; Turquet, Jean; Quod, Jean-Pascal; Schleyer, Michael H

2015-06-03

Coral diseases have caused a substantial decline in the biodiversity and abundance of reef-building corals. To date, more than 30 distinct diseases of scleractinian corals have been reported, which cause progressive tissue loss and/or affect coral growth, reproductive capacity, recruitment, species diversity and the abundance of reef-associated organisms. While coral disease research has increased over the last 4 decades, very little is known about coral diseases in the Western Indian Ocean. Surveys conducted at multiple sites in Reunion, South Africa and Mayotte between August 2010 and June 2012 revealed the presence of 6 main coral diseases: black band disease (BBD), white syndrome (WS), pink line syndrome (PLS), growth anomalies (GA), skeleton eroding band (SEB) and Porites white patch syndrome (PWPS). Overall, disease prevalence was higher in Reunion (7.5 ± 2.2%; mean ± SE) compared to South Africa (3.9 ± 0.8%) and Mayotte (2.7 ± 0.3%). Across locations, Acropora and Porites were the genera most susceptible to disease. Spatial variability was detected in both Reunion and South Africa, with BBD and WS more prevalent on shallow than deep reefs. There was also evidence of seasonality in 2 diseases: the prevalence of BBD and WS was higher in summer than winter. This was the first study to investigate the ecology of coral diseases, providing both qualitative and quantitative data, on Western Indian Ocean reefs, and surveys should be expanded to confirm these patterns.

[Progress of heterotrophic studies on symbiotic corals].

PubMed

Yang, Yang-Chu-Qiao; Hong, Wen Ting; Wang, Shu Hong

2017-12-01

Heterotrophy of zooxanthellae symbiotic corals refers to the nutrition directly coming from food absorption, not the nutrition obtained from photosynthesis. Most ex situ propagation of symbiotic corals focused on the effects of irradiation, flow rate and water quality on corals, few of them involved in the demand and supply of coral heterotrophic nutrition. This paper reviewed the significance of heterotrophic nutrient supply to symbiotic corals from the sources of coral heterotrophic nutrition, the factors affecting the supply of coral heterotrophic nutrient, and the methods of how to study the coral heterotrophy. In general, the research of coral heterotrophy is just at the beginning stage, and future studies should focus on the inherent mechanism of coral feeding selection and developing more effective research methods.

Learning of nature: The curious case of the naked mole rat.

PubMed

Lagunas-Rangel, Francisco Alejandro; Chávez-Valencia, Venice

2017-06-01

Naked mole rats (NMRs) are the longest-living rodents known, living up to approximately 30 years and showing sustained good health. Nowadays, NMRs are considered excellent models for aging and, additionally, for cancer research, due to the evidence of a remarkable cancer resistance demonstrated through thousands of necropsies performed with very few cases that describe this pathology, which is believed to be a disease that unavoidably accompanies aging. Since some years ago, several studies have tried to explain the possible mechanisms underlying longevity and cancer resistance in NMRs through different perspectives and directions, creating new knowledge that subsequently could be used for cancer prevention and delaying aging in humans. Thus, the purpose of this review is to summarize the recent knowledge on naked mole rats with a particular emphasis on the molecular mechanisms associated with their longevity and cancer resistance. Copyright © 2017 Elsevier B.V. All rights reserved.

A naked eye refractive index sensor with a visible multiple peak metamaterial absorber.

PubMed

Ma, Heli; Song, Kun; Zhou, Liang; Zhao, Xiaopeng

2015-03-26

We report a naked eye refractive index sensor with a visible metamaterial absorber. The visible metamaterial absorber consisting of a silver dendritic/dielectric/metal structure shows multiple absorption peaks. By incorporating a gain material (rhodamine B) into the dielectric layer, the maximal magnitude of the absorption peak can be improved by about 30%. As the metamaterial absorber is sensitive to the refractive index of glucose solutions, it can function as a sensor that quickly responds to variations of the refractive index of the liquid. Meanwhile, since the response is presented via color changes, it can be clearly observed by the naked eyes. Further experiments have confirmed that the sensor can be used repeatedly.

A paper-based cantilever array sensor: Monitoring volatile organic compounds with naked eye.

PubMed

Fraiwan, Arwa; Lee, Hankeun; Choi, Seokheun

2016-09-01

Volatile organic compound (VOC) detection is critical for controlling industrial and commercial emissions, environmental monitoring, and public health. Simple, portable, rapid and low-cost VOC sensing platforms offer the benefits of on-site and real-time monitoring anytime and anywhere. The best and most practically useful approaches to monitoring would include equipment-free and power-free detection by the naked eye. In this work, we created a novel, paper-based cantilever sensor array that allows simple and rapid naked-eye VOC detection without the need for power, electronics or readout interface/equipment. This simple VOC detection method was achieved using (i) low-cost paper materials as a substrate and (ii) swellable thin polymers adhered to the paper. Upon exposure to VOCs, the polymer swelling adhered to the paper-based cantilever, inducing mechanical deflection that generated a distinctive composite pattern of the deflection angles for a specific VOC. The angle is directly measured by the naked eye on a 3-D protractor printed on a paper facing the cantilevers. The generated angle patterns are subjected to statistical algorithms (linear discriminant analysis (LDA)) to classify each VOC sample and selectively detect a VOC. We classified four VOC samples with 100% accuracy using LDA. Copyright © 2016 Elsevier B.V. All rights reserved.

A Physical Model of Cosmogenic Nuclide Production in Stony and Iron Meteoroids on the Basis of Simulation Experiments

NASA Astrophysics Data System (ADS)

Leya, I.; Lange, H.-J.; Michel, R.; Meltzow, B.; Herpers, U.; Busemann, H.; Wieler, R.; Dittrich-Hannen, B.; Suter, M.; Kubik, P. W.

1995-09-01

By extending and improving earlier model calculations [1-4] of cosmogenic nuclide production by GCR particles in extraterrestrial matter, we can now present a physical model without free parameters for a consistent description of GCR production rates in stony and iron meteoroids. The model takes explicitely into account p and n-induced reactions. GCR 4He particles are considered only approximately. It is based on depth-size and bulk-chemistry-dependent spectra of primary and secondary protons and of secondary neutrons calculated by HET and MORSE codes within the HERMES code system [5] and on the cross sections of the underlying reactions. Comprehensive and reliable sets of proton cross sections from thresholds up to 2.6 GeV exist now for many cosmogenic nuclides (see [6] for a review). For n-induced reactions the situation is not so good. Only a few data at low energies and practically no data at higher energies exist. GCR production of cosmogenic nuclides in stony meteoroids is already dominated by neutron-induced reactions for most meteoroid radii. In iron meteoroids neutrons are even more important because of the high mass numbers of the bulk and of consequently higher multiplicities for production of secondary neutrons. In order to overcome this problem, the necessary excitation functions of neutron-induced reactions were determined from experimental thick-target production rates by least-squares unfolding procedures using the code STAYS'L [7]. The data were produced in laboratory experiments under completely controlled conditions [8-11]. The unfolding procedure starts from guess functions (from threshold up to 900 MeV) based on all available experimental neutron cross sections and on theoretical ones calculated by the AREL [12] code which is a relativistic version of the hybrid model of pre-equilibrium reactions [13]. With the new neutron cross sections it is possible to describe simultanously all data from the simulation experiments with an accuracy of better

Advancing Ocean Monitoring Near Coral Reefs

NASA Astrophysics Data System (ADS)

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

2010-10-01

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

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

PubMed Central

Englebert, Norbert; Bongaerts, Pim; Muir, Paul R.; Hay, Kyra B.; Pichon, Michel; Hoegh-Guldberg, Ove

2017-01-01

Mesophotic coral ecosystems in the Indo-Pacific remain relatively unexplored, particularly at lower mesophotic depths (≥60 m), despite their potentially large spatial extent. Here, we used a remotely operated vehicle to conduct a qualitative assessment of the zooxanthellate coral community at lower mesophotic depths (60–125 m) at 10 different locations in the Great Barrier Reef Marine Park and the Coral Sea Commonwealth Marine Reserve. Lower mesophotic coral communities were present at all 10 locations, with zooxanthellate scleractinian corals extending down to ~100 metres on walls and ~125 m on steep slopes. Lower mesophotic coral communities were most diverse in the 60–80 m zone, while at depths of ≥100 m the coral community consisted almost exclusively of the genus Leptoseris. Collections of coral specimens (n = 213) between 60 and 125 m depth confirmed the presence of at least 29 different species belonging to 18 genera, including several potential new species and geographic/depth range extensions. Overall, this study highlights that lower mesophotic coral ecosystems are likely to be ubiquitous features on the outer reefs of the Great Barrier Reef and atolls of the Coral Sea, and harbour a generic and species richness of corals that is much higher than thus far reported. Further research efforts are urgently required to better understand and manage these ecosystems as part of the Great Barrier Reef Marine Park and Coral Sea Commonwealth Marine Reserve. PMID:28146574

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

PubMed

Englebert, Norbert; Bongaerts, Pim; Muir, Paul R; Hay, Kyra B; Pichon, Michel; Hoegh-Guldberg, Ove

2017-01-01

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

Anti-Pathogenic Activity of Coral Bacteria Againts White Plaque Disease of Coral Dipsastraea from Tengah Island, Karimunjawa

NASA Astrophysics Data System (ADS)

Imam Muchlissin, Sakti; Sabdono, Agus; Permata W, Diah

2018-02-01

Coral disease is main factor of degrading coral reefs, such as White Plaque (WP) disease that cause loss of epidermal tissue of corals. The purposes of this research were to identify the bacteria associated with White Plaque Disease of coral Dipsastraea and to investigate coral bacteria that have antipathogenic potency against White Plaque Disease by Coral Dipsastraea. Sampling was carried out by purposive method in Tengah Island, Karimunjawa on March 2015. Streak method was used to isolate and purify coral bacteria, while overlay and agar diffusion method were used to test antibacterial activity. Identification of selected bacteria was conducted by biochemical and molecular methods. Polyphasic identification of bacteria associated with diseased coral White Plague of Dipsastraea. It is found that TFWP1, TFWP2, TFWP3 and TFWP4 were closely related to Bacillus antracis, Virgibacillus olivae, Virgibacillus salarius and Bacillus mojavensis, respectively. While antipathogen activity bacterial isolates, NM1.3, NM1.8 and NM2.3 were closely related to Pseudoalteromonas flavipulchra, Pseudoalteromonas piscicida, and Vibrio azureus, respectively. Phylogenetic data on microbial community composition in coral will help with the knowledge in the biological control of coral diseases.

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

PubMed Central

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

2016-01-01

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

Circadian clocks in symbiotic corals: the duet between Symbiodinium algae and their coral host.

PubMed

Sorek, Michal; Díaz-Almeyda, Erika M; Medina, Mónica; Levy, Oren

2014-04-01

To date, the association and synchronization between two organismal circadian clocks ticking in parallel as part of a meta-organism (termed a symbiotic association), have rarely been investigated. Reef-building corals exhibit complex rhythmic responses to diurnal, lunar, and annual changes. Understanding circadian, circatidal, and annual regulation in reef-building corals is complicated by the presence of photosynthetic endosymbionts, which have a profound physiochemical influence on the intracellular environment. How corals tune their animal-based clock machinery to respond to external cues while simultaneously responding to internal physiological changes imposed by the symbiont, is not clear. There is insufficient molecular or physiological evidence of the existence of a circadian pacemaker that controls the metabolism, photosynthesis, synchronized mass spawning, and calcification processes in symbiotic corals. In this review, we present current knowledge regarding the animal pacemaker and the symbiotic-algal pacemaker. We examine the evidence from behavioral, physiological, molecular, and evolutionary perspectives. We explain why symbiotic corals are an interesting model with which to study the complexities and evolution of the metazoan circadian clock. We also provide evidence of why the chronobiology of corals is fundamental and extremely important for explaining the biology, physiology, and metabolism of coral reefs. A deeper understanding of these complex issues can help explain coral mass spawning, one of the earth's greatest and most mysterious behavioral phenomena. Copyright © 2014 Elsevier B.V. All rights reserved.

In vivo silencing of alpha-synuclein using naked siRNA

PubMed Central

Lewis, Jada; Melrose, Heather; Bumcrot, David; Hope, Andrew; Zehr, Cynthia; Lincoln, Sarah; Braithwaite, Adam; He, Zhen; Ogholikhan, Sina; Hinkle, Kelly; Kent, Caroline; Toudjarska, Ivanka; Charisse, Klaus; Braich, Ravi; Pandey, Rajendra K; Heckman, Michael; Maraganore, Demetrius M; Crook, Julia; Farrer, Matthew J

2008-01-01

Background Overexpression of α-synuclein (SNCA) in families with multiplication mutations causes parkinsonism and subsequent dementia, characterized by diffuse Lewy Body disease post-mortem. Genetic variability in SNCA contributes to risk of idiopathic Parkinson's disease (PD), possibly as a result of overexpression. SNCA downregulation is therefore a valid therapeutic target for PD. Results We have identified human and murine-specific siRNA molecules which reduce SNCA in vitro. As a proof of concept, we demonstrate that direct infusion of chemically modified (naked), murine-specific siRNA into the hippocampus significantly reduces SNCA levels. Reduction of SNCA in the hippocampus and cortex persists for a minimum of 1 week post-infusion with recovery nearing control levels by 3 weeks post-infusion. Conclusion We have developed naked gene-specific siRNAs that silence expression of SNCA in vivo. This approach may prove beneficial toward our understanding of the endogenous functional equilibrium of SNCA, its role in disease, and eventually as a therapeutic strategy for α-synucleinopathies resulting from SNCA overexpression. PMID:18976489

Circular geodesics of naked singularities in the Kehagias-Sfetsos metric of Hořava's gravity

NASA Astrophysics Data System (ADS)

Vieira, Ronaldo S. S.; Schee, Jan; Kluźniak, Włodek; Stuchlík, Zdeněk; Abramowicz, Marek

2014-07-01

We discuss photon and test-particle orbits in the Kehagias-Sfetsos (KS) metric of Hořava's gravity. For any value of the Hořava parameter ω, there are values of the gravitational mass M for which the metric describes a naked singularity, and this is always accompanied by a vacuum "antigravity sphere" on whose surface a test particle can remain at rest (in a zero angular momentum geodesic), and inside which no circular geodesics exist. The observational appearance of an accreting KS naked singularity in a binary system would be that of a quasistatic spherical fluid shell surrounded by an accretion disk, whose properties depend on the value of M, but are always very different from accretion disks familiar from the Kerr-metric solutions. The properties of the corresponding circular orbits are qualitatively similar to those of the Reissner-Nordström naked singularities. When event horizons are present, the orbits outside the Kehagias-Sfetsos black hole are qualitatively similar to those of the Schwarzschild metric.

Naked at Our Age: Talking out Loud about Senior Sex

ERIC Educational Resources Information Center

Davis, Melanie

2012-01-01

"Naked at Our Age" is an excellent resource for sexually interested and/or active adults over the age of 60. The book combines the author's personal reflections, questions and stories shared by older adults, and advice from sex therapists, sexuality educators, the author, and health care providers. The breadth of topics makes the book useful to…

Living with marginal coral communities: Diversity and host-specificity in coral-associated barnacles in the northern coral distribution limit of the East China Sea.

PubMed

Chan, Benny K K; Xu, Guang; Kim, Hyun Kyong; Park, Jin-Ho; Kim, Won

2018-01-01

Corals and their associated fauna are extremely diverse in tropical waters and form major reefs. In the high-latitude temperate zone, corals living near their distribution limit are considered marginal communities because they are particularly extremely sensitive to environmental and climatic changes. In this study, we examined the diversity and host usage of coral-associated barnacles on Jeju Island, Korea, the northern coral distribution limit in the East China Sea. In this study, only three coral-associated barnacles-from two genera in two subfamilies-were collected. The Pyrgomatinid barnacles Cantellius arcuatus and Cantellius cf. euspinulosum were found only on the corals Montipora millepora and Alveopora japonica, respectively. The Megatrematinid barnacle Pyrgomina oulastreae, relatively a generalist, was found on Psammocora spp. (both profundacella and albopicta) and Oulastrea crispata corals. The host usage of these three barnacles does not overlap. DNA barcode sequences of the C. arcuatus specimens collected in the present study matched those collected in Kochi in Japan, Taiwan, Malaysia and Papua New Guinea, suggesting that this species has a wide geographical distribution. C. arcuatus covers a wider host range in Taiwan waters, inhabiting Montipora spp. and Porites spp., which suggests that the host specificity of coral-associated barnacles varies with host availability. C. cf. euspinulosum probably has a very narrow distribution and host usage. The sequences of C. cf. euspinulosum on Jeju Island do not match those of any known sequences of Cantellius barnacles in the Indo-Pacific region. P. oulastreae probably prefers cold water because it has been reported in temperate regions. Coral-associated barnacles in marginal communities have considerably lower diversity than their subtropical and tropical counterparts. When host availability is limited, marginal coral-associated barnacles exhibit higher host specificity than those in subtropical and tropical

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

PubMed

Hoey, Andrew S; Pratchett, Morgan S; Cvitanovic, Christopher

2011-01-01

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

High Macroalgal Cover and Low Coral Recruitment Undermines the Potential Resilience of the World's Southernmost Coral Reef Assemblages

PubMed Central

Hoey, Andrew S.; Pratchett, Morgan S.; Cvitanovic, Christopher

2011-01-01

Coral reefs are under increasing pressure from anthropogenic and climate-induced stressors. The ability of reefs to reassemble and regenerate after disturbances (i.e., resilience) is largely dependent on the capacity of herbivores to prevent macroalgal expansion, and the replenishment of coral populations through larval recruitment. Currently there is a paucity of this information for higher latitude, subtropical reefs. To assess the potential resilience of the benthic reef assemblages of Lord Howe Island (31°32′S, 159°04′E), the worlds' southernmost coral reef, we quantified the benthic composition, densities of juvenile corals (as a proxy for coral recruitment), and herbivorous fish communities. Despite some variation among habitats and sites, benthic communities were dominated by live scleractinian corals (mean cover 37.4%) and fleshy macroalgae (20.9%). Live coral cover was higher than in most other subtropical reefs and directly comparable to lower latitude tropical reefs. Juvenile coral densities (0.8 ind.m−2), however, were 5–200 times lower than those reported for tropical reefs. Overall, macroalgal cover was negatively related to the cover of live coral and the density of juvenile corals, but displayed no relationship with herbivorous fish biomass. The biomass of herbivorous fishes was relatively low (204 kg.ha−1), and in marked contrast to tropical reefs was dominated by macroalgal browsing species (84.1%) with relatively few grazing species. Despite their extremely low biomass, grazing fishes were positively related to both the density of juvenile corals and the cover of bare substrata, suggesting that they may enhance the recruitment of corals through the provision of suitable settlement sites. Although Lord Howe Islands' reefs are currently coral-dominated, the high macroalgal cover, coupled with limited coral recruitment and low coral growth rates suggest these reefs may be extremely susceptible to future disturbances. PMID:21991366

How can "Super Corals" facilitate global coral reef survival under rapid environmental and climatic change?

PubMed

Camp, Emma F; Schoepf, Verena; Suggett, David J

2018-03-26

Coral reefs are in a state of rapid global decline via environmental and climate change, and efforts have intensified to identify or engineer coral populations with increased resilience. Concurrent with these efforts has been increasing use of the popularized term "Super Coral" in both popular media and scientific literature without a unifying definition. However, how this subjective term is currently applied has the potential to mislead inference over factors contributing to coral survivorship, and the future trajectory of coral reef form and functioning. Here, we discuss that the information required to support a single definition does not exist, and in fact may never be appropriate, i.e. "How Super is Super"? Instead, we advocate caution of this term, and suggest a workflow that enables contextualization and clarification of superiority to ensure that inferred or asserted survivorship is appropriate into future reef projections. This is crucial to robustly unlock how "Super Corals" can be integrated into the suite of management options required to facilitate coral survival under rapid environmental and climate change. © 2018 John Wiley & Sons Ltd.

Electromagnetic radiation due to naked singularity formation in self-similar gravitational collapse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitsuda, Eiji; Yoshino, Hirotaka; Tomimatsu, Akira

Dynamical evolution of test fields in background geometry with a naked singularity is an important problem relevant to the Cauchy horizon instability and the observational signatures different from black hole formation. In this paper we study electromagnetic perturbations generated by a given current distribution in collapsing matter under a spherically symmetric self-similar background. Using the Green's function method, we construct the formula to evaluate the outgoing energy flux observed at the future null infinity. The contributions from 'quasinormal' modes of the self-similar system as well as 'high-frequency' waves are clarified. We find a characteristic power-law time evolution of the outgoingmore » energy flux which appears just before naked singularity formation and give the criteria as to whether or not the outgoing energy flux diverges at the future Cauchy horizon.« less

Expression pattern of cadherins in the naked mole rat (Heterocephalus glaber) suggests innate cortical diversification of the cerebrum.

PubMed

Matsunaga, Eiji; Nambu, Sanae; Iriki, Atsushi; Okanoya, Kazuo

2011-06-15

The cerebral cortex is an indispensable region for higher cognitive function that is remarkably diverse among mammalian species. Although previous research has shown that the cortical area map in the mammalian cerebral cortex is formed by innate and activity-dependent mechanisms, it remains unknown how these mechanisms contribute to the evolution and diversification of the functional cortical areas in various species. The naked mole rat (Heterocephalus glaber) is a subterranean, eusocial rodent. Physiological and anatomical studies have revealed that the visual system is regressed and the somatosensory system is enlarged. To examine whether species differences in cortical area development are caused by intrinsic factors or environmental factors, we performed comparative gene expression analysis of neonatal naked mole rat and mouse brains. The expression domain of cadherin-6, a somatosensory marker, was expanded caudally and shifted dorsally in the cortex, whereas the expression domain of cadherin-8, a visual marker, was reduced caudally in the neonatal naked mole rat cortex. The expression domain of cadherin-8 was also reduced in other visual areas, such as the lateral geniculate nucleus and superior colliculus. Immunohistochemical analysis of thalamocortical fibers further suggested that somatosensory input did not affect cortical gene expression in the neonatal naked mole rat brain. These results suggest that the development of the somatosensory system and the regression of the visual system in the naked mole rat cortex are due to intrinsic genetic mechanisms as well as sensory input-dependent mechanisms. Intrinsic genetic mechanisms thus appear to contribute to species diversity in cortical area formation. Copyright © 2011 Wiley-Liss, Inc.

Coral Mortality and Bleaching Output

EPA Science Inventory

COMBO is a spreadsheet-based model for the use of managers, conservationists, and biologists for projecting the effects of climate change on coral reefs at local-to-regional scales. The COMBO (Coral Mortality and Bleaching Output) model calculates the impacts to coral reefs from...

Suspended-sediment and turbidity responses to sediment and turbidity reduction projects in the Beaver Kill, Stony Clove Creek, and Warner Creek, Watersheds, New York, 2010–14

USGS Publications Warehouse

Siemion, Jason; McHale, Michael R.; Davis, Wae Danyelle

2016-12-05

Suspended-sediment concentrations (SSCs) and turbidity were monitored within the Beaver Kill, Stony Clove Creek, and Warner Creek tributaries to the upper Esopus Creek in New York, the main source of water to the Ashokan Reservoir, from October 1, 2010, through September 30, 2014. The purpose of the monitoring was to determine the effects of suspended-sediment and turbidity reduction projects (STRPs) on SSC and turbidity in two of the three streams; no STRPs were constructed in the Beaver Kill watershed. During the study period, four STRPs were completed in the Stony Clove Creek and Warner Creek watersheds. Daily mean SSCs decreased significantly for a given streamflow after the STRPs were completed. The most substantial decreases in daily mean SSCs were measured at the highest streamflows. Background SSCs, as measured in water samples collected in upstream reference stream reaches, in all three streams in this study were less than 5 milligrams per liter during low and high streamflows. Longitudinal stream sampling identified stream reaches with failing hillslopes in contact with the stream channel as the primary sediment sources in the Beaver Kill and Stony Clove Creek watersheds.

Bottlenecks to coral recovery in the Seychelles

NASA Astrophysics Data System (ADS)

Chong-Seng, K. M.; Graham, N. A. J.; Pratchett, M. S.

2014-06-01

Processes that affect recovery of coral assemblages require investigation because coral reefs are experiencing a diverse array of more frequent disturbances. Potential bottlenecks to coral recovery include limited larval supply, low rates of settlement, and high mortality of new recruits or juvenile corals. We investigated spatial variation in local abundance of scleractinian corals in the Seychelles at three distinct life history stages (recruits, juveniles, and adults) on reefs with differing benthic conditions. Following widespread coral loss due to the 1998 bleaching event, some reefs are recovering (i.e., relatively high scleractinian coral cover: `coral-dominated'), some reefs have low cover of living macrobenthos and unconsolidated rubble substrates (`rubble-dominated'), and some reefs have high cover of macroalgae (`macroalgal-dominated'). Rates of coral recruitment to artificial settlement tiles were similar across all reef conditions, suggesting that larval supply does not explain differential coral recovery across the three reef types. However, acroporid recruits were absent on macroalgal-dominated reefs (0.0 ± 0.0 recruits tile-1) in comparison to coral-dominated reefs (5.2 ± 1.6 recruits tile-1). Juvenile coral colony density was significantly lower on macroalgal-dominated reefs (2.4 ± 1.1 colonies m-2), compared to coral-dominated reefs (16.8 ± 2.4 m-2) and rubble-dominated reefs (33.1 ± 7.3 m-2), suggesting that macroalgal-dominated reefs have either a bottleneck to successful settlement on the natural substrates or a high post-settlement mortality bottleneck. Rubble-dominated reefs had very low cover of adult corals (10.0 ± 1.7 %) compared to coral-dominated reefs (33.4 ± 3.6 %) despite no statistical difference in their juvenile coral densities. A bottleneck caused by low juvenile colony survivorship on unconsolidated rubble-dominated reefs is possible, or alternatively, recruitment to rubble-dominated reefs has only recently begun. This

The biology and economics of coral growth.

PubMed

Osinga, Ronald; Schutter, Miriam; Griffioen, Ben; Wijffels, René H; Verreth, Johan A J; Shafir, Shai; Henard, Stéphane; Taruffi, Maura; Gili, Claudia; Lavorano, Silvia

2011-08-01

To protect natural coral reefs, it is of utmost importance to understand how the growth of the main reef-building organisms-the zooxanthellate scleractinian corals-is controlled. Understanding coral growth is also relevant for coral aquaculture, which is a rapidly developing business. This review paper provides a comprehensive overview of factors that can influence the growth of zooxanthellate scleractinian corals, with particular emphasis on interactions between these factors. Furthermore, the kinetic principles underlying coral growth are discussed. The reviewed information is put into an economic perspective by making an estimation of the costs of coral aquaculture.

Hurricanes benefit bleached corals

PubMed Central

Manzello, Derek P.; Brandt, Marilyn; Smith, Tyler B.; Lirman, Diego; Hendee, James C.; Nemeth, Richard S.

2007-01-01

Recent, global mass-mortalities of reef corals due to record warm sea temperatures have led researchers to consider global warming as one of the most significant threats to the persistence of coral reef ecosystems. The passage of a hurricane can alleviate thermal stress on coral reefs, highlighting the potential for hurricane-associated cooling to mitigate climate change impacts. We provide evidence that hurricane-induced cooling was responsible for the documented differences in the extent and recovery time of coral bleaching between the Florida Reef Tract and the U.S. Virgin Islands during the Caribbean-wide 2005 bleaching event. These results are the only known scenario where the effects of a hurricane can benefit a stressed marine community. PMID:17606914

Hurricanes benefit bleached corals.

PubMed

Manzello, Derek P; Brandt, Marilyn; Smith, Tyler B; Lirman, Diego; Hendee, James C; Nemeth, Richard S

2007-07-17

Recent, global mass-mortalities of reef corals due to record warm sea temperatures have led researchers to consider global warming as one of the most significant threats to the persistence of coral reef ecosystems. The passage of a hurricane can alleviate thermal stress on coral reefs, highlighting the potential for hurricane-associated cooling to mitigate climate change impacts. We provide evidence that hurricane-induced cooling was responsible for the documented differences in the extent and recovery time of coral bleaching between the Florida Reef Tract and the U.S. Virgin Islands during the Caribbean-wide 2005 bleaching event. These results are the only known scenario where the effects of a hurricane can benefit a stressed marine community.

String loops in the field of braneworld spherically symmetric black holes and naked singularities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stuchlík, Z.; Kološ, M., E-mail: zdenek.stuchlik@fpf.slu.cz, E-mail: martin.kolos@fpf.slu.cz

We study motion of current-carrying string loops in the field of braneworld spherically symmetric black holes and naked singularities. The spacetime is described by the Reissner-Nordström geometry with tidal charge b reflecting the non-local tidal effects coming from the external dimension; both positive and negative values of the spacetime parameter b are considered. We restrict attention to the axisymmetric motion of string loops when the motion can be fully governed by an appropriately defined effective potential related to the energy and angular momentum of the string loops. In dependence on these two constants of the motion, the string loops canmore » be captured, trapped, or can escape to infinity. In close vicinity of stable equilibrium points at the centre of trapped states the motion is regular. We describe how it is transformed to chaotic motion with growing energy of the string loop. In the field of naked singularities the trapped states located off the equatorial plane of the system exist and trajectories unable to cross the equatorial plane occur, contrary to the trajectories in the field of black holes where crossing the equatorial plane is always admitted. We concentrate our attention to the so called transmutation effect when the string loops are accelerated in the deep gravitational field near the black hole or naked singularity by transforming the oscillatory energy to the energy of the transitional motion. We demonstrate that the influence of the tidal charge can be substantial especially in the naked singularity spacetimes with b > 1 where the acceleration to ultrarelativistic velocities with Lorentz factor γ ∼ 100 can be reached, being more than one order higher in comparison with those obtained in the black hole spacetimes.« less

Microbial disease and the coral holobiont

USGS Publications Warehouse

Bourne, David G.; Garren, Melissa; Work, Thierry M.; Rosenberg, Eugene; Smith, Garriet W.; Harvell, C. Drew

2009-01-01

Tropical coral reefs harbour a reservoir of enormous biodiversity that is increasingly threatened by direct human activities and indirect global climate shifts. Emerging coral diseases are one serious threat implicated in extensive reef deterioration through disruption of the integrity of the coral holobiont – a complex symbiosis between the coral animal, endobiotic alga and an array of microorganisms. In this article, we review our current understanding of the role of microorganisms in coral health and disease, and highlight the pressing interdisciplinary research priorities required to elucidate the mechanisms of disease. We advocate an approach that applies knowledge gained from experiences in human and veterinary medicine, integrated into multidisciplinary studies that investigate the interactions between host, agent and environment of a given coral disease. These approaches include robust and precise disease diagnosis, standardised ecological methods and application of rapidly developing DNA, RNA and protein technologies, alongside established histological, microbial ecology and ecological expertise. Such approaches will allow a better understanding of the causes of coral mortality and coral reef declines and help assess potential management options to mitigate their effects in the longer term.

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.

Expression of acid-sensing ion channels and selection of reference genes in mouse and naked mole rat.

PubMed

Schuhmacher, Laura-Nadine; Smith, Ewan St John

2016-12-13

Acid-sensing ion channels (ASICs) are a family of ion channels comprised of six subunits encoded by four genes and they are expressed throughout the peripheral and central nervous systems. ASICs have been implicated in a wide range of physiological and pathophysiological processes: pain, breathing, synaptic plasticity and excitotoxicity. Unlike mice and humans, naked mole-rats do not perceive acid as a noxious stimulus, even though their sensory neurons express functional ASICs, likely an adaptation to living in a hypercapnic subterranean environment. Previous studies of ASIC expression in the mammalian nervous system have often not examined all subunits, or have failed to adequately quantify expression between tissues; to date there has been no attempt to determine ASIC expression in the central nervous system of the naked mole-rat. Here we perform a geNorm study to identify reliable housekeeping genes in both mouse and naked mole-rat and then use quantitative real-time PCR to estimate the relative amounts of ASIC transcripts in different tissues of both species. We identify RPL13A (ribosomal protein L13A) and CANX (calnexin), and β-ACTIN and EIF4A (eukaryotic initiation factor 4a) as being the most stably expressed housekeeping genes in mouse and naked mole-rat, respectively. In both species, ASIC3 was most highly expressed in dorsal root ganglia (DRG), and ASIC1a, ASIC2b and ASIC3 were more highly expressed across all brain regions compared to the other subunits. We also show that ASIC4, a proton-insensitive subunit of relatively unknown function, was highly expressed in all mouse tissues apart from DRG and hippocampus, but was by contrast the lowliest expressed ASIC in all naked mole-rat tissues.

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

PubMed

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

2012-06-01

Caribbean reef corals have declined precipitously since the 1980s due to regional episodes of bleaching, disease and algal overgrowth, but the extent of earlier degradation due to localised historical disturbances such as land clearing and overfishing remains unresolved. We analysed coral and molluscan fossil assemblages from reefs near Bocas del Toro, Panama to construct a timeline of ecological change from the 19th century-present. We report large changes before 1960 in coastal lagoons coincident with extensive deforestation, and after 1960 on offshore reefs. Striking changes include the demise of previously dominant staghorn coral Acropora cervicornis and oyster Dendrostrea frons that lives attached to gorgonians and staghorn corals. Reductions in bivalve size and simplification of gastropod trophic structure further implicate increasing environmental stress on reefs. Our paleoecological data strongly support the hypothesis, from extensive qualitative data, that Caribbean reef degradation predates coral bleaching and disease outbreaks linked to anthropogenic climate change. © 2012 Blackwell Publishing Ltd/CNRS.

The CORALS Connection

ERIC Educational Resources Information Center

Plankis, Brian; Klein, Carolyn

2010-01-01

The Ocean, Reefs, Aquariums, Literacy, and Stewardship (CORALS) research program helps students connect global environmental issues to local concerns and personal choices. During the 18-week program, students strengthen their understanding of coral reef decline through a classroom aquarium activity, communicate with science experts, and create…

Coral bleaching--capacity for acclimatization and adaptation.

PubMed

Coles, S L; Brown, Barbara E

2003-01-01

Coral bleaching, i.e., loss of most of the symbiotic zooxanthellae normally found within coral tissue, has occurred with increasing frequency on coral reefs throughout the world in the last 20 years, mostly during periods of El Nino Southern Oscillation (ENSO). Experiments and observations indicate that coral bleaching results primarily from elevated seawater temperatures under high light conditions, which increases rates of biochemical reactions associated with zooxanthellar photosynthesis, producing toxic forms of oxygen that interfere with cellular processes. Published projections of a baseline of increasing ocean temperature resulting from global warming have suggested that annual temperature maxima within 30 years may be at levels that will cause frequent coral bleaching and widespread mortality leading to decline of corals as dominant organisms on reefs. However, these projections have not considered the high variability in bleaching response that occurs among corals both within and among species. There is information that corals and their symbionts may be capable of acclimatization and selective adaptation to elevated temperatures that have already resulted in bleaching resistant coral populations, both locally and regionally, in various areas of the world. There are possible mechanisms that might provide resistance and protection to increased temperature and light. These include inducible heat shock proteins that act in refolding denatured cellular and structural proteins, production of oxidative enzymes that inactivate harmful oxygen radicals, fluorescent coral pigments that both reflect and dissipate light energy, and phenotypic adaptations of zooxanthellae and adaptive shifts in their populations at higher temperatures. Such mechanisms, when considered in conjunction with experimental and observational evidence for coral recovery in areas that have undergone coral bleaching, suggest an as yet undefined capacity in corals and zooxanthellae to adapt to

Modeling coral calcification accounting for the impacts of coral bleaching and ocean acidification

NASA Astrophysics Data System (ADS)

Evenhuis, C.; Lenton, A.; Cantin, N. E.; Lough, J. M.

2014-01-01

Coral reefs are diverse ecosystems threatened by rising CO2 levels that are driving the observed increases in sea surface temperature and ocean acidification. Here we present a new unified model that links changes in temperature and carbonate chemistry to coral health. Changes in coral health and population are able to explicitly modelled by linking the rates of growth, recovery and calcification to the rates of bleaching and temperature stress induced mortality. The model is underpinned by four key principles: the Arrhenius equation, thermal specialisation, resource allocation trade-offs, and adaption to local environments. These general relationships allow this model to be constructed from a range of experimental and observational data. The different characteristics of this model are also assessed against independent data to show that the model captures the observed response of corals. We also provide new insights into the factors that determine calcification rates and provide a framework based on well-known biological principles for understanding the observed global distribution of calcification rates. Our results suggest that, despite the implicit complexity of the coral reef environment, a simple model based on temperature, carbonate chemistry and different species can reproduce much of the observed response of corals to changes in temperature and ocean acidification.

Modelling coral calcification accounting for the impacts of coral bleaching and ocean acidification

NASA Astrophysics Data System (ADS)

Evenhuis, C.; Lenton, A.; Cantin, N. E.; Lough, J. M.

2015-05-01

Coral reefs are diverse ecosystems that are threatened by rising CO2 levels through increases in sea surface temperature and ocean acidification. Here we present a new unified model that links changes in temperature and carbonate chemistry to coral health. Changes in coral health and population are explicitly modelled by linking rates of growth, recovery and calcification to rates of bleaching and temperature-stress-induced mortality. The model is underpinned by four key principles: the Arrhenius equation, thermal specialisation, correlated up- and down-regulation of traits that are consistent with resource allocation trade-offs, and adaption to local environments. These general relationships allow this model to be constructed from a range of experimental and observational data. The performance of the model is assessed against independent data to demonstrate how it can capture the observed response of corals to stress. We also provide new insights into the factors that determine calcification rates and provide a framework based on well-known biological principles to help understand the observed global distribution of calcification rates. Our results suggest that, despite the implicit complexity of the coral reef environment, a simple model based on temperature, carbonate chemistry and different species can give insights into how corals respond to changes in temperature and ocean acidification.

Monitoring Growth of Hard Corals as Performance Indicators for Coral Reefs

ERIC Educational Resources Information Center

Crabbe, M. James; Karaviotis, Sarah; Smith, David J.

2004-01-01

Digital videophotography, computer image analysis and physical measurements have been used to monitor sedimentation rates, coral cover, genera richness, rugosity, and estimated recruitment dates of massive corals at three different sites in the Wakatobi Marine National Park, Indonesia, and on the reefs around Discovery Bay, Jamaica.…

Live coral repels a common reef fish ectoparasite

NASA Astrophysics Data System (ADS)

Artim, J. M.; Sikkel, P. C.

2013-06-01

Coral reefs are undergoing rapid changes as living corals give way to dead coral on which other benthic organisms grow. This decline in live coral could influence habitat availability for fish parasites with benthic life stages. Gnathiid isopod larvae live in the substratum and are common blood-feeding parasites of reef fishes. We examined substrate associations and preferences of a common Caribbean gnathiid, Gnathia marleyi. Emergence traps set over predominantly live coral substrata captured significantly fewer gnathiids than traps set over dead coral substrata. In laboratory experiments, gnathiids preferred dead coral and sponge and tended to avoid contact with live coral. When live gnathiids were added to containers with dead or live coral, significantly fewer were recovered from the latter after 24 h. Our data therefore suggest that live coral is not suitable microhabitat for parasitic gnathiid isopods and that a decrease in live coral cover increases available habitat for gnathiids.

Dietary shift in juvenile coral trout ( Plectropomus maculatus) following coral reef degradation from a flood plume disturbance

NASA Astrophysics Data System (ADS)

Wen, Colin K. C.; Bonin, Mary C.; Harrison, Hugo B.; Williamson, David H.; Jones, Geoffrey P.

2016-06-01

Acute environmental disturbances impact on habitat quality and resource availability, which can reverberate through trophic levels and become apparent in species' dietary composition. In this study, we observed a distinct dietary shift of newly settled and juvenile coral trout ( Plectropomus maculatus) following severe coral reef habitat degradation after a river flood plume affected the Keppel Islands, Australia. Hard coral cover declined by ~28 % in the 2 yr following the 2010-2011 floods, as did the abundance of young coral trout. Gut contents analysis revealed that diets had shifted from largely crustacean-based to non-preferred prey fishes following the disturbances. These results suggest that newly settled and juvenile coral trout modify their diet and foraging strategy in response to coral habitat degradation. This bottom-up effect of habitat degradation on the diet of a top coral reef predator may incur a metabolic cost, with subsequent effects on growth and survival.

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

NASA Astrophysics Data System (ADS)

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

2016-09-01

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

Warm waters, bleached corals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, L.

1990-10-12

Two researchers, Tom Goreau of the Discovery Laboratory in Jamaica and Raymond Hayes of Howard University, claim that they have evidence that nearly clinches the temperature connection to the bleached corals in the Caribbean and that the coral bleaching is an indication of Greenhouse warming. The incidents of scattered bleaching of corals, which have been reported for decades, are increasing in both intensity and frequency. The researchers based their theory on increased temperature of the seas measured by satellites. However, some other scientists feel that the satellites measure the temperature of only the top few millimeters of the water andmore » that since corals lie on reefs perhaps 60 to 100 feet below the ocean surface, the elevated temperatures are not significant.« less

Coral reef fish predator maintains olfactory acuity in degraded coral habitats.

PubMed

Natt, Michael; Lönnstedt, Oona M; McCormick, Mark I

2017-01-01

Coral reefs around the world are rapidly degrading due to a range of environmental stressors. Habitat degradation modifies the sensory landscape within which predator-prey interactions occur, with implications for olfactory-mediated behaviours. Predator naïve settlement-stage damselfish rely on conspecific damage-released odours (i.e., alarm odours) to inform risk assessments. Yet, species such as the Ambon damselfish, Pomacentrus amboinensis, become unable to respond appropriately to these cues when living in dead-degraded coral habitats, leading to increased mortality through loss of vigilance. Reef fish predators also rely on odours from damaged prey to locate, assess prey quality and engage in prey-stealing, but it is unknown whether their responses are also modified by the change to dead-degraded coral habitats. Implications for prey clearly depend on how their predatory counterparts are affected, therefore the present study tested whether olfactory-mediated foraging responses in the dusky dottyback, Pseudochromis fuscus, a common predator of P. amboinensis, were similarly affected by coral degradation. A y-maze was used to measure the ability of Ps. fuscus to detect and move towards odours, against different background water sources. Ps. fuscus were exposed to damage-released odours from juvenile P. amboinensis, or a control cue of seawater, against a background of seawater treated with either healthy or dead-degraded hard coral. Predators exhibited an increased time allocation to the chambers of y-mazes injected with damage-released odours, with comparable levels of response in both healthy and dead-degraded coral treated waters. In control treatments, where damage-released odours were replaced with a control seawater cue, fish showed no increased preference for either chamber of the y-maze. Our results suggest that olfactory-mediated foraging behaviours may persist in Ps. fuscus within dead-degraded coral habitats. Ps. fuscus may consequently gain a

Naked singularities are not singular in distorted gravity

NASA Astrophysics Data System (ADS)

Garattini, Remo; Majumder, Barun

2014-07-01

We compute the Zero Point Energy (ZPE) induced by a naked singularity with the help of a reformulation of the Wheele-DeWitt equation. A variational approach is used for the calculation with Gaussian Trial Wave Functionals. The one loop contribution of the graviton to the ZPE is extracted keeping under control the UltraViolet divergences by means of a distorted gravitational field. Two examples of distortion are taken under consideration: Gravity's Rainbow and Noncommutative Geometry. Surprisingly, we find that the ZPE is no more singular when we approach the singularity.

Role of endosymbiotic zooxanthellae and coral mucus in the adhesion of the coral-bleaching pathogen Vibrio shiloi to its host.

PubMed

Banin, E; Israely, T; Fine, M; Loya, Y; Rosenberg, E

2001-05-15

Vibrio shiloi, the causative agent of bleaching the coral Oculina patagonica in the Mediterranean Sea, adheres to its coral host by a beta-D-galactopyranoside-containing receptor on the coral surface. The receptor is present in the coral mucus, since V. shiloi adhered avidly to mucus-coated ELISA plates. Adhesion was inhibited by methyl-beta-D-galactopyranoside. Removal of the mucus from O. patagonica resulted in a delay in adhesion of V. shiloi to the coral, corresponding to regeneration of the mucus. DCMU inhibited the recovery of adhesion of the bacteria to the mucus-depleted corals, indicating that active photosynthesis by the endosymbiotic zooxanthellae was necessary for the synthesis or secretion of the receptor. Further evidence of the role of the zooxanthellae in producing the receptor came from a study of adhesion of V. shiloi to different species of corals. The bacteria failed to adhere to bleached corals and white (azooxanthellate) O. patagonica cave corals, both of which lacked the algae. In addition, V. shiloi adhered to two Mediterranean corals (Madracis and Cladocora) that contained zooxanthellae and did not adhere to two azooxanthellate Mediterranean corals (Phyllangia and Polycyathus). V. shiloi demonstrated positive chemotaxis towards the mucus of O. patagonica. The data demonstrate that endosymbiotic zooxanthellae contribute to the production of coral mucus and that V. shiloi infects only mucus-containing, zooxanthellate corals.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 fallmore » 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.« less

Abundance and composition of juvenile corals reveals divergent trajectories for coral assemblages across the United Arab Emirates.

PubMed

Pratchett, Morgan S; Baird, Andrew H; Bauman, Andrew G; Burt, John A

2017-01-30

Marked shifts in the composition of coral assemblages are occurring at many locations, but it is unknown whether these are permanent shifts reinforced by patterns of population replenishment. This study examined the composition of juvenile coral assemblages across the United Arab Emirates (UAE). Densities of juvenile corals varied significantly among locations, but were highest where coral cover was highest. Juvenile coral assemblages within the Persian Gulf were dominated by Porites, while no Acropora were recorded. We expect therefore, continued declines in Acropora abundance, while observed dominance of Porites is likely to persist. In the Oman Sea, Pocillopora was the dominant juvenile coral, with Acropora and Stylophora also recorded. This study shows that taxonomic differences in replenishment are reinforcing temporal shifts in coral composition within the southern Persian Gulf, but not in the Oman Sea. Differences in environmental conditions and disturbance regimes likely explain the divergent responses between regions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Does seaweed-coral competition make seaweeds more palatable?

NASA Astrophysics Data System (ADS)

Longo, G. O.; Hay, M. E.

2015-03-01

Seaweed-coral interactions are increasingly common on modern coral reefs, but the dynamics, processes, and mechanisms affecting these interactions are inadequately understood. We investigated the frequency and effect of seaweed-coral contacts for common seaweeds and corals in Belize. Effects on corals were evaluated by measuring the frequency and extent of bleaching when contacted by various seaweeds, and effects on a common seaweed were evaluated by assessing whether contact with coral made the seaweed more palatable to the sea urchin Diadema antillarum. Coral-seaweed contacts were particularly frequent between Agaricia corals and the seaweed Halimeda opuntia, with this interaction being associated with coral bleaching in 95 % of contacts. Pooling across all coral species, H. opuntia was the seaweed most commonly contacting corals and most frequently associated with localized bleaching at the point of contact. Articulated coralline algae, Halimeda tuna and Lobophora variegata also frequently contacted corals and were commonly associated with bleaching. The common corals Agaricia and Porites bleached with similar frequency when contacted by H. opuntia (95 and 90 %, respectively), but Agaricia experienced more damage than Porites when contacted by articulated coralline algae or H. tuna. When spatially paired individuals of H. opuntia that had been in contact with Agaricia and not in contact with any coral were collected from the reefs and offered to D. antillarum, urchins consumed about 150 % more of thalli that had been competing with Agaricia. Contact and non-contact thalli did not differ in nutritional traits (ash-free-dry-mass, C or N concentrations), suggesting that Halimeda chemical defenses may have been compromised by coral-algal contact. If competition with corals commonly enhances seaweed palatability, then the dynamics and nuances of small-scale seaweed-coral-herbivore interactions at coral edges are deserving of greater attention in that such

The Urgent Need for Robust Coral Disease Diagnostics

PubMed Central

Pollock, F. Joseph; Morris, Pamela J.; Willis, Bette L.; Bourne, David G.

2011-01-01

Coral disease has emerged over recent decades as a significant threat to coral reef ecosystems, with declines in coral cover and diversity of Caribbean reefs providing an example of the potential impacts of disease at regional scales. If similar trends are to be mitigated or avoided on reefs worldwide, a deeper understanding of the factors underlying the origin and spread of coral diseases and the steps that can be taken to prevent, control, or reduce their impacts is required. In recent years, an increased focus on coral microbiology and the application of classic culture techniques and emerging molecular technologies has revealed several coral pathogens that could serve as targets for novel coral disease diagnostic tools. The ability to detect and quantify microbial agents identified as indicators of coral disease will aid in the elucidation of disease causation and facilitate coral disease detection and diagnosis, pathogen monitoring in individuals and ecosystems, and identification of pathogen sources, vectors, and reservoirs. This information will advance the field of coral disease research and contribute knowledge necessary for effective coral reef management. This paper establishes the need for sensitive and specific molecular-based coral pathogen detection, outlines the emerging technologies that could serve as the basis of a new generation of coral disease diagnostic assays, and addresses the unique challenges inherent to the application of these techniques to environmentally derived coral samples. PMID:22028646

Reef scent: How brooded coral larvae from a tough coral smell their way to a new home

NASA Astrophysics Data System (ADS)

Spies, N.; Richmond, R. H.; Seneca, F.; Murphy, J.; Martinez, J.; Lyman, A.

2016-02-01

Coral reefs are highly diverse marine ecosystems of ecological, economic, and cultural value. With the expected negative effects on reefs from global climate change including rising sea temperatures and ocean acidification, the identification of resilient coral species has become increasingly important. Leptastrea purpurea is an encrusting coral that is found throughout the Indo-Pacific and Red Sea. While most corals are broadcast spawners, releasing sperm and eggs to be fertilized in the water column, some corals brood embryos within their tissues after internal fertilization. L. purpurea appears to release planula larvae on a continuous basis from the parent colony as observed during two years of monitoring. The planula larvae show remarkable resilience under a wide range of stressful conditions including temperature, sediment, and chemical stressors, as well as the ability to successfully settle and metamorphose after 180 days in controlled laboratory conditions. Various smells were tested to identify a settlement cue for L. purpurea larvae, and our results suggest that the smell associated with other coral colonies induce larval settlement and metamorphosis. Knowledge of the settlement cues and reproductive biology of this coral is important to our understanding of coral resilience in the face of anthropogenic perturbation.

50 CFR 223.208 - Corals.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Sanctuaries Act 16 U.S.C. 1431 et seq. NOAA, NOS Coral Reef Conservation Act 16 U.S.C. 6406 Commandant, U.S... Management; Coral Reef RestorationFL Statute § 390.0558 Florida Fish and Wildlife Conservation Commission... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Corals. 223.208 Section 223.208 Wildlife...

50 CFR 223.208 - Corals.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Sanctuaries Act 16 U.S.C. 1431 et seq. NOAA, NOS Coral Reef Conservation Act 16 U.S.C. 6406 Commandant, U.S... Management; Coral Reef RestorationFL Statute § 390.0558 Florida Fish and Wildlife Conservation Commission... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Corals. 223.208 Section 223.208 Wildlife...

50 CFR 223.208 - Corals.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Sanctuaries Act 16 U.S.C. 1431 et seq. NOAA, NOS Coral Reef Conservation Act 16 U.S.C. 6406 Commandant, U.S... Management; Coral Reef RestorationFL Statute § 390.0558 Florida Fish and Wildlife Conservation Commission... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Corals. 223.208 Section 223.208 Wildlife...

50 CFR 223.208 - Corals.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Act 16 U.S.C. 1431 et seq. NOAA, NOS Coral Reef Conservation Act 16 U.S.C. 6406 Commandant, U.S. Coast...; Coral Reef RestorationFL Statute § 390.0558 Florida Fish and Wildlife Conservation Commission Fish and... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Corals. 223.208 Section 223.208 Wildlife...

50 CFR 223.208 - Corals.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Sanctuaries Act 16 U.S.C. 1431 et seq. NOAA, NOS Coral Reef Conservation Act 16 U.S.C. 6406 Commandant, U.S... Management; Coral Reef RestorationFL Statute § 390.0558 Florida Fish and Wildlife Conservation Commission... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Corals. 223.208 Section 223.208 Wildlife...

The future of coral reefs

NASA Astrophysics Data System (ADS)

Knowlton, Nancy

2001-05-01

Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived "weedy" corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1°C, a likely result of global climate change, can cause coral "bleaching" (the breakdown of coral-algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent.

Coral reproduction in Western Australia

PubMed Central

Speed, Conrad W.; Babcock, Russ

2016-01-01

Larval production and recruitment underpin the maintenance of coral populations, but these early life history stages are vulnerable to extreme variation in physical conditions. Environmental managers aim to minimise human impacts during significant periods of larval production and recruitment on reefs, but doing so requires knowledge of the modes and timing of coral reproduction. Most corals are hermaphroditic or gonochoric, with a brooding or broadcast spawning mode of reproduction. Brooding corals are a significant component of some reefs and produce larvae over consecutive months. Broadcast spawning corals are more common and display considerable variation in their patterns of spawning among reefs. Highly synchronous spawning can occur on reefs around Australia, particularly on the Great Barrier Reef. On Australia’s remote north-west coast there have been fewer studies of coral reproduction. The recent industrial expansion into these regions has facilitated research, but the associated data are often contained within confidential reports. Here we combine information in this grey-literature with that available publicly to update our knowledge of coral reproduction in WA, for tens of thousands of corals and hundreds of species from over a dozen reefs spanning 20° of latitude. We identified broad patterns in coral reproduction, but more detailed insights were hindered by biased sampling; most studies focused on species of Acropora sampled over a few months at several reefs. Within the existing data, there was a latitudinal gradient in spawning activity among seasons, with mass spawning during autumn occurring on all reefs (but the temperate south-west). Participation in a smaller, multi-specific spawning during spring decreased from approximately one quarter of corals on the Kimberley Oceanic reefs to little participation at Ningaloo. Within these seasons, spawning was concentrated in March and/or April, and October and/or November, depending on the timing of

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

NASA Astrophysics Data System (ADS)

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

2011-06-01

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

Asymptotic behavior of dynamical variables and naked singularity formation in spherically symmetric gravitational collapse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawakami, Hayato; Mitsuda, Eiji; Nambu, Yasusada

In considering the gravitational collapse of matter, it is an important problem to clarify what kind of conditions leads to the formation of naked singularity. For this purpose, we apply the 1+3 orthonormal frame formalism introduced by Uggla et al. to the spherically symmetric gravitational collapse of a perfect fluid. This formalism allows us to construct an autonomous system of evolution and constraint equations for scale-invariant dynamical variables normalized by the volume expansion rate of the timelike orthonormal frame vector. We investigate the asymptotic evolution of such dynamical variables towards the formation of a central singularity and present a conjecturemore » that the steep spatial gradient for the normalized density function is a characteristic of the naked singularity formation.« less

Characterizing lesions in corals from American Samoa

NASA Astrophysics Data System (ADS)

Work, T. M.; Rameyer, R. A.

2005-11-01

The study of coral disease has suffered from an absence of systematic approaches that are commonly used to determine causes of diseases in animals. There is a critical need to develop a standardized and portable nomenclature for coral lesions in the field and to incorporate more commonly available biomedical tools in coral disease surveys to determine the potential causes of lesions in corals. We characterized lesions in corals from American Samoa based on gross and microscopic morphology and classified them as discoloration, growth anomalies, or tissue loss. The most common microscopic finding in corals manifesting discoloration was the depletion of zooxanthellae, followed by necrosis, sometimes associated with invasive algae or fungi. The most common microscopic lesion in corals manifesting tissue loss was cell necrosis often associated with algae, fungi, or protozoa. Corals with growth anomaly had microscopic evidence of hyperplasia of gastrovascular canals, followed by necrosis associated with algae or metazoa (polychaete worms). Several species of apparently normal corals also had microscopic changes, including the presence of bacterial aggregates or crustacea in tissues. A single type of gross lesion (e.g., discoloration) could have different microscopic manifestations. This phenomenon underlines the importance of using microscopy to provide a more systematic description of coral lesions and to detect potential pathogens associated with these lesions.

Characterizing lesions in corals from American Samoa

USGS Publications Warehouse

Work, Thierry M.; Rameyer, Robert A.

2005-01-01

The study of coral disease has suffered from an absence of systematic approaches that are commonly used to determine causes of diseases in animals. There is a critical need to develop a standardized and portable nomenclature for coral lesions in the field and to incorporate more commonly available biomedical tools in coral disease surveys to determine the potential causes of lesions in corals. We characterized lesions in corals from American Samoa based on gross and microscopic morphology and classified them as discoloration, growth anomalies, or tissue loss. The most common microscopic finding in corals manifesting discoloration was the depletion of zooxanthellae, followed by necrosis, sometimes associated with invasive algae or fungi. The most common microscopic lesion in corals manifesting tissue loss was cell necrosis often associated with algae, fungi, or protozoa. Corals with growth anomaly had microscopic evidence of hyperplasia of gastrovascular canals, followed by necrosis associated with algae or metazoa (polychaete worms). Several species of apparently normal corals also had microscopic changes, including the presence of bacterial aggregates or crustacea in tissues. A single type of gross lesion (e.g., discoloration) could have different microscopic manifestations. This phenomenon underlines the importance of using microscopy to provide a more systematic description of coral lesions and to detect potential pathogens associated with these lesions.

Evaluating coral reef health in American Samoa

USGS Publications Warehouse

Work, Thierry M.; Rameyer, Robert A.

2005-01-01

The study of coral disease has suffered from an absence of systematic approaches that are commonly used to determine causes of diseases in animals. There is a critical need to develop a standardized and portable nomenclature for coral lesions in the field and to incorporate more commonly available biomedical tools in coral disease surveys to determine the potential causes of lesions in corals. We characterized lesions in corals from American Samoa based on gross and microscopic morphology and classified them as discoloration, growth anomalies, or tissue loss. The most common microscopic finding in corals manifesting discoloration was the depletion of zooxanthellae, followed by necrosis, sometimes associated with invasive algae or fungi. The most common microscopic lesion in corals manifesting tissue loss was cell necrosis often associated with algae, fungi, or protozoa. Corals with growth anomaly had microscopic evidence of hyperplasia of gastrovascular canals, followed by necrosis associated with algae or metazoa (polychaete worms). Several species of apparently normal corals also had microscopic changes, including the presence of bacterial aggregates or crustacea in tissues. A single type of gross lesion (e.g., discoloration) could have different microscopic manifestations. This phenomenon underlines the importance of using microscopy to provide a more systematic description of coral lesions and to detect potential pathogens associated with these lesions.

Coral calcification and ocean acidification

USGS Publications Warehouse

Jokiel, Paul L.; Jury, Christopher P.; Kuffner, Ilsa B.

2016-01-01

Over 60 years ago, the discovery that light increased calcification in the coral plant-animal symbiosis triggered interest in explaining the phenomenon and understanding the mechanisms involved. Major findings along the way include the observation that carbon fixed by photosynthesis in the zooxanthellae is translocated to animal cells throughout the colony and that corals can therefore live as autotrophs in many situations. Recent research has focused on explaining the observed reduction in calcification rate with increasing ocean acidification (OA). Experiments have shown a direct correlation between declining ocean pH, declining aragonite saturation state (Ωarag), declining [CO32_] and coral calcification. Nearly all previous reports on OA identify Ωarag or its surrogate [CO32] as the factor driving coral calcification. However, the alternate “Proton Flux Hypothesis” stated that coral calcification is controlled by diffusion limitation of net H+ transport through the boundary layer in relation to availability of dissolved inorganic carbon (DIC). The “Two Compartment Proton Flux Model” expanded this explanation and synthesized diverse observations into a universal model that explains many paradoxes of coral metabolism, morphology and plasticity of growth form in addition to observed coral skeletal growth response to OA. It is now clear that irradiance is the main driver of net photosynthesis (Pnet), which in turn drives net calcification (Gnet), and alters pH in the bulk water surrounding the coral. Pnet controls [CO32] and thus Ωarag of the bulk water over the diel cycle. Changes in Ωarag and pH lag behind Gnet throughout the daily cycle by two or more hours. The flux rate Pnet, rather than concentration-based parameters (e.g., Ωarag, [CO3 2], pH and [DIC]:[H+] ratio) is the primary driver of Gnet. Daytime coral metabolism rapidly removes DIC from the bulk seawater. Photosynthesis increases the bulk seawater pH while providing the energy that drives

Response of coral reefs to climate change: Expansion and demise of the southernmost Pacific coral reef

NASA Astrophysics Data System (ADS)

Woodroffe, Colin D.; Brooke, Brendan P.; Linklater, Michelle; Kennedy, David M.; Jones, Brian G.; Buchanan, Cameron; Mleczko, Richard; Hua, Quan; Zhao, Jian-xin

2010-08-01

Coral reefs track sea level and are particularly sensitive to changes in climate. Reefs are threatened by global warming, with many experiencing increased coral bleaching. Warmer sea surface temperatures might enable reef expansion into mid latitudes. Here we report multibeam sonar and coring that reveal an extensive relict coral reef around Lord Howe Island, which is fringed by the southernmost reef in the Pacific Ocean. The relict reef, in water depths of 25-50 m, flourished in early Holocene and covered an area more than 20 times larger than the modern reef. Radiocarbon and uranium-series dating indicates that corals grew between 9000 and 7000 years ago. The reef was subsequently drowned, and backstepped to its modern limited extent. This relict reef, with localised re-establishment of corals in the past three millennia, could become a substrate for reef expansion in response to warmer temperatures, anticipated later this century and beyond, if corals are able to recolonise its surface.

The effect of no naked pancreatic surface in the cavity of jejunum on pancreaticojejunostomy in 132 consecutive cases.

PubMed

Zhang, Fumin; Jin, Jichun; Jiang, Hao; Wang, Shiyang; Gu, Hanbao; Jin, Xinglin

2015-01-01

To prevent the pancreatic fistulas, we designed a technique termed "no naked pancreatic surface in the cavity of jejunum" on pancreaticojejunostomy. We adopted pancreatic exocrine secretions following the pancreatic duct by drainage; there was no naked pancreatic surface in the cavity of jejunum, and entail 2-3 cm sheath of the jejunum to the pancreatic stump. Only 3 (2.27%) cases developed pancreatic fistulas, 1 patient had a grade A leak, and 2 patients had grade B leakage. The overall morbidity was 25.76%. There was no dilatation of pancreatic duct or pancreatic enzyme deficiency shown during followed-up. The duration for accomplishing the anastomosis was 20 minutes averagely. The technique of no naked pancreatic surface in the cavity of jejunum can be routinely used in any case with pancreaticojejunostomy. It is a safe, simple, and effective technique that avoids the primary complication of anastomotic leakage.

The northernmost coral frontier of the Maldives: The coral reefs of Ihavandippolu Atoll under long-term environmental change.

PubMed

Tkachenko, Konstantin S

2012-12-01

Ihavandippolu, the northernmost atoll of the Maldives, experienced severe coral bleaching and mortality in 1998 followed by several bleaching episodes in the last decade. Coral cover in the 11 study sites surveyed in July-December of 2011 in the 3-5 m depth range varied from 1.7 to 51%. Reefs of the islands located in the center of Ihavandippolu lagoon have exhibited a very low coral recovery since 1998 and remain mostly degraded 12 years after the impact. At the same time, some reefs, especially in the inner part of the eastern ring of the atoll, demonstrate a high coral cover (>40%) with a dominance of branching Acropora that is known to be one of the coral genera that is most susceptible to thermal stress. The last severe bleaching event in 2010 resulted in high coral mortality in some sites of the atoll. Differences in coral mortality rates and proportion between "susceptible" and "resistant" taxa in study sites are apparently related to long-term adaptation and local hydrological features that can mitigate thermal impacts. Abundant herbivorous fish observed in the atoll prevent coral overgrowth by macroalgae even on degraded reefs. Despite the frequent influence of temperature anomalies and having less geomorphologic refuges for coral survivals than other larger Maldivian atolls, a major part of observed coral communities in Ihavandippolu Atoll exhibits high resilience and potential for further acclimatization to a changing environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Coral-associated micro-organisms and their roles in promoting coral health and thwarting diseases

PubMed Central

Krediet, Cory J.; Ritchie, Kim B.; Paul, Valerie J.; Teplitski, Max

2013-01-01

Over the last decade, significant advances have been made in characterization of the coral microbiota. Shifts in its composition often correlate with the appearance of signs of diseases and/or bleaching, thus suggesting a link between microbes, coral health and stability of reef ecosystems. The understanding of interactions in coral-associated microbiota is informed by the on-going characterization of other microbiomes, which suggest that metabolic pathways and functional capabilities define the ‘core’ microbiota more accurately than the taxonomic diversity of its members. Consistent with this hypothesis, there does not appear to be a consensus on the specificity in the interactions of corals with microbial commensals, even though recent studies report potentially beneficial functions of the coral-associated bacteria. They cycle sulphur, fix nitrogen, produce antimicrobial compounds, inhibit cell-to-cell signalling and disrupt virulence in opportunistic pathogens. While their beneficial functions have been documented, it is not certain whether or how these microbes are selected by the hosts. Therefore, understanding the role of innate immunity, signal and nutrient exchange in the establishment of coral microbiota and in controlling its functions will probably reveal ancient, evolutionarily conserved mechanisms that dictate the outcomes of host–microbial interactions, and impact the resilience of the host. PMID:23363627

Benthic metabolic feedbacks to carbonate chemistry on coral reefs:implications for ocean acidification

NASA Astrophysics Data System (ADS)

Price, N.; Rohwer, F. L.; Stuart, S. A.; Andersson, A.; Smith, J.

2012-12-01

The metabolic activity of resident organisms can cause spatio-temporal variability in carbonate chemistry within the benthic boundary layer, and thus potentially buffer the global impacts of ocean acidification. But, little is known about the capacity for particular species assemblages to contribute to natural daily variability in carbonate chemistry. We encapsulated replicate areas (~3m2) of reef across six Northern Line Islands in the central Pacific for 24 hrs to quantify feedbacks to carbonate chemistry within the benthic boundary layer from community metabolism. Underneath each 'tent', we quantified relative abundance and biomass of each species of corals and algae. We coupled high temporal resolution time series data on the natural diurnal variability in pH, dissolved oxygen, salinity, and temperature (using autonomous sensors) with resident organisms' net community calcification and productivity rates (using change in total dissolved carbon and total alkalinity over time) to examine feedbacks from reef metabolism to boundary layer carbonate chemistry. These reefs experienced large ranges in pH (> 0.2 amplitude) each day, similar to the magnitude of 'acidification' expected over the next century. Daily benthic pH, pCO2, and aragonite saturation state (Ωaragonite) were contrasted with seasonal threshold values estimated from open ocean climatological data extrapolated at each island to determine relative inter-island feedbacks. Diurnal amplitude in pH, pCO2, and Ωaragonite at each island was dependent upon the resident species assemblage of the benthos and was particularly reliant upon the biomass, productivity, and calcification rate of Halimeda. Net primary productivity of fleshy algae (algal turfs and Lobophora spp.) predominated on degraded, inhabited islands where net community calcification was negligible. In contrast, the chemistry over reefs on 'pristine', uninhabited islands was driven largely by net calcification of calcareous algae and stony

Unprecedented Disease-Related Coral Mortality in Southeastern Florida.

PubMed

Precht, William F; Gintert, Brooke E; Robbart, Martha L; Fura, Ryan; van Woesik, Robert

2016-08-10

Anomalously high water temperatures, associated with climate change, are increasing the global prevalence of coral bleaching, coral diseases, and coral-mortality events. Coral bleaching and disease outbreaks are often inter-related phenomena, since many coral diseases are a consequence of opportunistic pathogens that further compromise thermally stressed colonies. Yet, most coral diseases have low prevalence (<5%), and are not considered contagious. By contrast, we document the impact of an extremely high-prevalence outbreak (61%) of white-plague disease at 14 sites off southeastern Florida. White-plague disease was observed near Virginia Key, Florida, in September 2014, and after 12 months had spread 100 km north and 30 km south. The disease outbreak directly followed a high temperature coral-bleaching event and affected at least 13 coral species. Eusmilia fastigiata, Meandrina meandrites, and Dichocoenia stokesi were the most heavily impacted coral species, and were reduced to <3% of their initial population densities. A number of other coral species, including Colpophyllia natans, Pseudodiploria strigosa, Diploria labyrinthiformis, and Orbicella annularis were reduced to <25% of their initial densities. The high prevalence of disease, the number of susceptible species, and the high mortality of corals affected suggests this disease outbreak is arguably one of the most lethal ever recorded on a contemporary coral reef.

Unprecedented Disease-Related Coral Mortality in Southeastern Florida

NASA Astrophysics Data System (ADS)

Precht, William F.; Gintert, Brooke E.; Robbart, Martha L.; Fura, Ryan; van Woesik, Robert

2016-08-01

Anomalously high water temperatures, associated with climate change, are increasing the global prevalence of coral bleaching, coral diseases, and coral-mortality events. Coral bleaching and disease outbreaks are often inter-related phenomena, since many coral diseases are a consequence of opportunistic pathogens that further compromise thermally stressed colonies. Yet, most coral diseases have low prevalence (<5%), and are not considered contagious. By contrast, we document the impact of an extremely high-prevalence outbreak (61%) of white-plague disease at 14 sites off southeastern Florida. White-plague disease was observed near Virginia Key, Florida, in September 2014, and after 12 months had spread 100 km north and 30 km south. The disease outbreak directly followed a high temperature coral-bleaching event and affected at least 13 coral species. Eusmilia fastigiata, Meandrina meandrites, and Dichocoenia stokesi were the most heavily impacted coral species, and were reduced to <3% of their initial population densities. A number of other coral species, including Colpophyllia natans, Pseudodiploria strigosa, Diploria labyrinthiformis, and Orbicella annularis were reduced to <25% of their initial densities. The high prevalence of disease, the number of susceptible species, and the high mortality of corals affected suggests this disease outbreak is arguably one of the most lethal ever recorded on a contemporary coral reef.

Why do naked singularities form in gravitational collapse? II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joshi, Pankaj S.; Goswami, Rituparno; Dadhich, Naresh

We examine physical features that could lead to formation of a naked singularity rather than black hole, as end state of spherical collapse. Generalizing earlier results on dust collapse to general type I matter fields, it is shown that collapse always creates black hole if shear vanishes or density is homogeneous. It follows that nonzero shear is a necessary condition for singularity to be visible to external observers, when trapped surface formation is delayed by shearing forces or inhomogeneity within the collapsing cloud.

Mine waste disposal leads to lower coral cover, reduced species richness and a predominance of simple coral growth forms on a fringing coral reef in Papua New Guinea.

PubMed

Haywood, M D E; Dennis, D; Thomson, D P; Pillans, R D

2016-04-01

A large gold mine has been operating at the Lihir Island Group, Papua New Guinea since 1997. The mine disposes of waste rock in nearshore waters, impacting nearby coral communities. During 2010, 2012 we conducted photographic surveys at 73 sites within 40 km of the mine to document impacts of mining operations on the hard coral communities. Coral communities close to the mine (∼2 km to the north and south of the mine) were depaurperate, but surprisingly, coral cover and community composition beyond this range appeared to be relatively similar, suggesting that the mine impacts were limited spatially. In particular, we found mining operations have resulted in a significant decrease in coral cover (4.4% 1.48 km from the disposal site c.f. 66.9% 10.36 km from the disposal site), decreased species richness and a predominance of less complex growth forms within ∼2 km to the north and south of the mine waste disposal site. In contrast to the two 'snapshot' surveys of corals performed in 2010 and 2012, long term data (1999-2012) based on visual estimates of coral cover suggested that impacts on coral communities may have been more extensive than this. With global pressures on the world's coral reefs increasing, it is vital that local, direct anthropogenic pressures are reduced, in order to help offset the impacts of climate change, disease and predation. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

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

PubMed

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

2015-06-26

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

Distinct Bacterial Communities Associated with Massive and Branching Scleractinian Corals and Potential Linkages to Coral Susceptibility to Thermal or Cold Stress

PubMed Central

Liang, Jiayuan; Yu, Kefu; Wang, Yinghui; Huang, Xueyong; Huang, Wen; Qin, Zhenjun; Pan, Ziliang; Yao, Qiucui; Wang, Wenhuan; Wu, Zhengchao

2017-01-01

It is well known that different coral species have different tolerances to thermal or cold stress, which is presumed to be related to the density of Symbiodinium. However, the intrinsic factors between stress-tolerant characteristics and coral-associated bacteria are rarely studied. In this study, 16 massive coral and 9 branching coral colonies from 6 families, 10 genera, and 18 species were collected at the same time and location (Xinyi Reef) in the South China Sea to investigate the bacterial communities. The results of an alpha diversity analysis showed that bacterial diversities associated with massive corals were generally higher than those with branching corals at different taxonomic levels (phylum, class, order, and so on). In addition, hierarchical clustering tree and PCoA analyses showed that coral species were clustered into two large groups according to the similarity of bacterial communities. Group I consisted of massive Goniastrea, Plesiastrea, Leptastrea, Platygyra, Echinopora, Porites, and Leptoria, and group II consisted of branching Acropora and Pocillopora. These findings suggested that both massive corals and branching corals have their own preference for the choice of associated bacteria, which may be involved in observed differences in thermal/cold tolerances. Further analysis found that 55 bacterial phyla, including 43 formally described phyla and 12 candidate phyla, were detected in these coral species. Among them, 52 phyla were recovered from the massive coral group, and 46 phyla were recovered from the branching coral group. Formally described coral pathogens have not been detected in these coral species, suggesting that they are less likely to be threatened by disease in this geographic area. This study highlights a clear relationship between the high complexity of bacterial community associated with coral, skeletal morphology of coral and potentially tolerances to thermal or cold stress. PMID:28642738

ASSESSMENT OF CORAL CONDITION

EPA Science Inventory

Complex reef structures formed by calcified coral skeletons provide a physical habitat that produces highly-valued ecosystem services, including shoreline protection and a high diversity and abundance of marine organisms that support lucrative fishing and tourism. Yet, coral reef...

Allometric growth in reef-building corals.

PubMed

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

2017-03-29

Predicting demographic rates is a critical part of forecasting the future of ecosystems under global change. Here, we test if growth rates can be predicted from morphological traits for a highly diverse group of colonial symbiotic organisms: scleractinian corals. We ask whether growth is isometric or allometric among corals, and whether most variation in coral growth rates occurs at the level of the species or morphological group. We estimate growth as change in planar area for 11 species, across five morphological groups and over 5 years. We show that coral growth rates are best predicted from colony size and morphology rather than species. Coral size follows a power scaling law with a constant exponent of 0.91. Despite being colonial organisms, corals have consistent allometric scaling in growth. This consistency simplifies the task of projecting community responses to disturbance and climate change. © 2017 The Author(s).

The influence of fire-coral colony size and agonistic behaviour of territorial damselfish on associated coral reef fish communities.

PubMed

Leal, Isabela Carolina Silva; de Araújo, Maria Elisabeth; da Cunha, Simone Rabelo; Pereira, Pedro Henrique Cipresso

2015-07-01

Branching hydrocorals from the genus Millepora play an important ecological role in South Atlantic reefs, where branching scleractinian corals are absent. Previous studies have shown a high proportion of reef fish species using branching fire-coral colonies as shelter, breeding, and feeding sites. However, the effects of Millepora spp. colony size and how the agonistic behaviour of a competitive damselfish affect the associated reef fish community are still unknown. The present study examined how fire-coral colony volume and the presence of a highly territorial and aggressive damselfish (Brazilian endemic Stegastes fuscus) affects the reef fish community associated with the fire-coral Millepora alcicornis. M. alcicornis colonies were surveyed from September 2012 to April 2013 at Tamandaré Reefs off Northeast Brazil. Our results show that the abundance and richness of coral associated fish was positively correlated with M. alcicornis coral colony volume. Additionally, behaviour of S. fuscus, the most abundant reef fish species found associated with fire-coral colonies (almost 57% of the fish community), was also influenced by fire-coral colony volume. There was a clear trend of increased agonistic behaviour and feeding on coral polyps as colony volume increased. This trend was reversed for the non-occupational swimming category, which decreased as M. alcicornis colony volume increased. Behavioural ontogenetic changes were also detected for S. fuscus individuals. Juveniles mainly showed two distinct behaviours: sheltered on coral branches and feeding on coral polyps. In contrast, adults presented greater equitability among the behavioural categories, mostly non-occupational swimming around coral colonies and agonistic behaviour. Lastly, S. fuscus individuals actively defended fire-coral colonies from intruders. A large number of agonistic interactions occurred against potential food competitors, which were mainly roving herbivores, omnivores, and sessile

Mid-term coral-algal dynamics and conservation status of a Gorgona Island (Tropical Eastern Pacific) coral reef.

PubMed

Zapata, Fernando A; Rodríguez-Ramírez, Alberto; Caro-Zambrano, Carlos; Garzón-Ferreira, Jaime

2010-05-01

Colombian coral reefs, as other reefs worldwide, have deteriorated significantly during the last few decades due to both natural and anthropogenic disturbances. The National Monitoring System for Coral Reefs in Colombia (SIMAC) was established in 1998 to provide long-term data bases to assess the changes of Colombian coral reefs against perturbations and to identify the factors responsible for their decline or recovery. On the Pacific coast, data on coral and algal cover have been collected yearly during seven consecutive years (1998-2004) from 20 permanent transects in two sites at La Azufrada reef, Gorgona Island. Overall, coral cover was high (55.1%-65.7%) and algal cover low (28.8%-37.5%) and both exhibited significant changes among years, most notably on shallow areas. Differences between sites in both coral and algal cover were present since the study began and may be explained by differences in sedimentation stress derived from soil runoff. Differences between depths most likely stem from the effects of low tidal sub-aerial exposures. Particularly intense sub-aerial exposures occurred repeatedly during January-March, 2001 and accounted for a decrease in coral and an increase in algal cover on shallow depths observed later that year. Additionally, the shallow area on the Northern site seems to be negatively affected by the combined effect of sedimentation and low tidal exposure. However, a decrease in coral cover and an increase of algal cover since 2001 on deep areas at both sites remain unexplained. Comparisons with previous studies suggest that the reef at La Azufrada has been more resilient than other reefs in the Tropical Eastern Pacific (TEP), recovering pre-disturbance (1979) levels of coral cover within a 10 year period after the 1982-83 El Niño, which caused 85% mortality. Furthermore, the effects of the 1997-98 El Niño, indicated by the difference in overall live coral cover between 1998 and 1999, were minor (< 6% reduction). Despite recurrent

Discordant coral-symbiont structuring: factors shaping geographical variation of Symbiodinium communities in a facultative zooxanthellate coral genus, Oculina

NASA Astrophysics Data System (ADS)

Leydet, Karine Posbic; Hellberg, Michael E.

2016-06-01

Understanding the factors that help shape the association between corals and their algal symbionts, zooxanthellae ( Symbiodinium), is necessary to better understand the functional diversity and acclimatization potential of the coral host. However, most studies focus on tropical zooxanthellate corals and their obligate algal symbionts, thus limiting our full comprehension of coral-algal symbiont associations. Here, we examine algal associations in a facultative zooxanthellate coral. We survey the Symbiodinium communities associated with Oculina corals in the western North Atlantic and the Mediterranean using one clade-level marker ( psbA coding region) and three fine-scale markers ( cp23S- rDNA, b7sym15 flanking region, and b2sym17). We ask whether Oculina spp. harbor geographically different Symbiodinium communities across their geographic range and, if so, whether the host's genetics or habitat differences are correlated with this geographical variation. We found that Oculina corals harbor different Symbiodinium communities across their geographical range. Of the habitat differences (including chlorophyll a concentration and depth), sea surface temperature is better correlated with this geographical variation than the host's genetics, a pattern most evident in the Mediterranean. Our results suggest that although facultative zooxanthellate corals may be less dependent on their algal partners compared to obligate zooxanthellate corals, the Symbiodinium communities that they harbor may nevertheless reflect acclimatization to environmental variation among habitats.

Evidence of photosymbiosis in Palaeozoic tabulate corals.

PubMed

Zapalski, Mikolaj K

2014-01-22

Coral reefs form the most diverse of all marine ecosystems on the Earth. Corals are among their main components and owe their bioconstructing abilities to a symbiosis with algae (Symbiodinium). The coral-algae symbiosis had been traced back to the Triassic (ca 240 Ma). Modern reef-building corals (Scleractinia) appeared after the Permian-Triassic crisis; in the Palaeozoic, some of the main reef constructors were extinct tabulate corals. The calcium carbonate secreted by extant photosymbiotic corals bears characteristic isotope (C and O) signatures. The analysis of tabulate corals belonging to four orders (Favositida, Heliolitida, Syringoporida and Auloporida) from Silurian to Permian strata of Europe and Africa shows these characteristic carbon and oxygen stable isotope signatures. The δ(18)O to δ(13)C ratios in recent photosymbiotic scleractinians are very similar to those of Palaeozoic tabulates, thus providing strong evidence of such symbioses as early as the Middle Silurian (ca 430 Ma). Corals in Palaeozoic reefs used the same cellular mechanisms for carbonate secretion as recent reefs, and thus contributed to reef formation.

Monitoring the coral disease, plague type II, on coral reefs in St. John, U.S. Virgin Islands

USGS Publications Warehouse

Miller, J.; Rogers, C.; Waara, R.

2003-01-01

In July 1997, conspicuous white patches of necrotic tissue and bare skeleton began to appear on scleractinian corals in several bays around St. John, US Virgin Islands. Analysis of diseased coral tissue from five different species confirmed the presence of a Sphingomonas-like bacterium, the pathogen for plague type II. To date, 14 species of hard corals have been affected by plague type II around St. John. This disease was monitored at Haulover and Tektite Reefs at depths of 7-12 meters. The study site at Tektite Reef has >50% cover by scleractinian corals with 90% of hard corals being composed of Montastraea annular is. Monthly surveys at Tektite Reef from December 1997 to May 2001 documented new incidence of disease (bare white patches of skeleton) every month with associated loss of living coral and 90.5% of all disease patches occurred on M. annularis. The frequency of disease within transects ranged from 3 to 58%, and the area of disease patches ranged from 0.25 to 9000 cm2. The average percent cover by the disease within 1 m2 ranged from 0.01% (?? 0.04 SD) to 1.74% (?? 9.08 SD). Photo-monitoring of 28 diseased corals of 9 species begun in September 1997 at Haulover Reef revealed no recovery of diseased portions with all necrotic tissue being overgrown rapidly by turf algae, usually within less than one month. Most coral colonies suffered partial mortality. Very limited recruitment (e.g., of Agaricia spp., Favia spp. and sponges) has been noted on the diseased areas. This coral disease has the potential to cause more loss of live coral on St. John reefs than any other stress to date because it targets the dominant reef building species, M. annularis.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

...-Grouper Fishery Off the Southern Atlantic States and Coral and Coral Reefs Fishery in the South Atlantic... the South Atlantic Region and the FMP for Coral, Coral Reefs, and Live/Hard Bottom Habitats of the... Aquariums to collect, with certain conditions, various species of reef fish and live rock in Federal waters...

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

How do corals make rocks?

NASA Astrophysics Data System (ADS)

Falkowski, P. G.; Mass, T.; Drake, J.; Schaller, M. F.; Rosenthal, Y.; Schofield, O.; Sherrell, R. M.

2014-12-01

We have developed a three pronged approach to understanding how corals precipitate aragonite crystals and contain proxy biogeochemical information. Using proteomic and genomic approaches, we have identified 35 proteins in coral skeletons. Among these are a series of coral acidic proteins (CARPs). Based on their gene sequences, we cloned a subset of these proteins and purified them. Each of the proteins precipitate aragonite in vitro in unamended seawater. Antibodies raised against these proteins react with individual crystals of the native coral, clearly revealing that they are part of a biomineral structure. Based on the primary structure of the proteins we have developed a model of the precipitation reaction that focuses on a Lewis acid displacement of protons from bicarbonate anions by calcium ligated to the carboxyl groups on the CARPs. The reactions are highly acidic and are not manifestly influenced by pH above ca. 6. These results suggest that corals will maintain the ability to calcify in the coming centuries, despite acidification of the oceans.

RESISTANCE AND RESILIENCE TO CORAL BLEACHING: IMPLICATIONS FOR CORAL REEF CONSERVATION AND MANAGEMENT

EPA Science Inventory

The massive scale of the 1997–1998 El Nino–associated coral bleaching event underscores the need for strategies to mitigate biodiversity losses resulting from temperature-induced coral mortality. As baseline sea surface temperatures continue to rise, climate change may represent ...

RESISTANCE AND RESILIENCE TO CORAL BLEACHING: IMPLICATIONS FOR CORAL REEF CONSERVATION AND MANAGEMENT

EPA Science Inventory

The massive scale of the 1997-1998 El Nino-associated coral bleaching event underscores the need for strategies to mitigate biodiversity losses resulting from temperature-induced coral mortality. As baseline sea surface temperatures continue to rise, climate change may represent ...

Discovery of naked charm particles and lifetime differences among charm species using nuclear emulsion techniques innovated in Japan

PubMed Central

NIU, Kiyoshi

2008-01-01

This is a historical review of the discovery of naked charm particles and lifetime differences among charm species. These discoveries in the field of cosmic-ray physics were made by the innovation of nuclear emulsion techniques in Japan. A pair of naked charm particles was discovered in 1971 in a cosmic-ray interaction, three years prior to the discovery of the hidden charm particle, J/Ψ, in western countries. Lifetime differences between charged and neutral charm particles were pointed out in 1975, which were later re-confirmed by the collaborative Experiment E531 at Fermilab. Japanese physicists led by K.Niu made essential contributions to it with improved emulsion techniques, complemented by electronic detectors. This review also discusses the discovery of artificially produced naked charm particles by us in an accelerator experiment at Fermilab in 1975 and of multiple-pair productions of charm particles in a single interaction in 1987 by the collaborative Experiment WA75 at CERN. PMID:18941283

Fluctuations in coral health of four common inshore reef corals in response to seasonal and anthropogenic changes in water quality.

PubMed

Browne, Nicola K; Tay, Jason K L; Low, Jeffrey; Larson, Ole; Todd, Peter A

2015-04-01

Environmental drivers of coral condition (maximum quantum yield, symbiont density, chlorophyll a content and coral skeletal growth rates) were assessed in the equatorial inshore coastal waters of Singapore, where the amplitude of seasonal variation is low, but anthropogenic influence is relatively high. Water quality variables (sediments, nutrients, trace metals, temperature, light) explained between 52 and 83% of the variation in coral condition, with sediments and light availability as key drivers of foliose corals (Merulina ampliata, Pachyseris speciosa), and temperature exerting a greater influence on a branching coral (Pocillopora damicornis). Seasonal reductions in water quality led to high chlorophyll a concentrations and maximum quantum yields in corals, but low growth rates. These marginal coral communities are potentially vulnerable to climate change, hence, we propose water quality thresholds for coral growth with the aim of mitigating both local and global environmental impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Temperature and Light Effects on Extracellular Superoxide Production by Algal and Bacterial Symbionts in Corals: Implications for Coral Bleaching

NASA Astrophysics Data System (ADS)

Brighi, C.; Diaz, J. M.; Apprill, A.; Hansel, C. M.

2014-12-01

Increased surface seawater temperature due to global warming is one of the main causes of coral bleaching, a phenomenon in which corals lose their photosynthetic algae. Light and temperature induced production of superoxide and other reactive oxygen species (ROS) by these symbiotic algae has been implicated in the breakdown of their symbiotic association with the coral host and subsequent coral bleaching. Nevertheless, a direct link between Symbiodinium ROS production and coral bleaching has not been demonstrated. In fact, given the abundance and diversity of microorganisms within the coral holobiont, the concentration and fluxes of ROS within corals may involve several microbial sources and sinks. Here, we explore the role of increased light and temperature on superoxide production by coral-derived cultures of Symbiodinium algae and Oceanospirillales bacteria of the genus Endozoicomonas, which are globally common and abundant associates of corals. Using a high sensitivity chemiluminescent technique, we find that heat stress (exposure to 34°C vs. 23°C for 2hr or 24hr) has no significant effect on extracellular superoxide production by Symbiodinium isolates within clades B and C, regardless of the level of light exposure. Exposure to high light, however, increased superoxide production by these organisms at both 34°C and 23°C. On the other hand, extracellular superoxide production by Endozoicomonas bacteria tested under the same conditions was stimulated by the combined effects of thermal and light stress. The results of this research suggest that the sources and physical triggers for biological superoxide production within corals are more complex than currently assumed. Thus, further investigations into the biological processes controlling ROS dynamics within corals are required to improve our understanding of the mechanisms underpinning coral bleaching and to aid in the development of mitigation strategies.

River discharge reduces reef coral diversity in Palau.

PubMed

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

2011-04-01

Coral community structure is often governed by a suite of processes that are becoming increasingly influenced by land-use changes and related terrestrial discharges. We studied sites along a watershed gradient to examine both the physical environment and the associated biological communities. Transplanted corals showed no differences in growth rates and mortality along the watershed gradient. However, coral cover, coral richness, and coral colony density increased with increasing distance from the mouth of the bay. There was a negative relationship between coral cover and mean suspended solids concentration. Negative relationships were also found between terrigenous sedimentation rates and the richness of adult and juvenile corals. These results have major implications not only for Pacific islands but for all countries with reef systems downstream of rivers. Land development very often leads to increases in river runoff and suspended solids concentrations that reduce coral cover and coral diversity on adjacent reefs. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effects of temperature and salinity on survival rate of cultured corals and photosynthetic efficiency of zooxanthellae in coral tissues

NASA Astrophysics Data System (ADS)

Kuanui, Pataporn; Chavanich, Suchana; Viyakarn, Voranop; Omori, Makoto; Lin, Chiahsin

2015-06-01

This study investigated the effects of temperature and salinity on growth, survival, and photosynthetic efficiency of three coral species, namely, Pocillopora damicornis, Acropora millepora and Platygyra sinensis of different ages (6 and 18 months old). The experimental corals were cultivated via sexual propagation. Colonies were exposed to 5 different temperatures (18, 23, 28, 33, and 38°C) and 5 different salinities (22, 27, 32, 37, and 42 psu). Results showed that temperature significantly affected photosynthetic efficiency (Fv/Fm) (p < 0.05) compared to salinity. The maximum quantum yield of corals decreased ranging from 5% to 100% when these corals were exposed to different temperatures and salinities. Temperature also significantly affected coral growth and survival. However, corals exposed to changes in salinity showed higher survivorship than those exposed to changes in temperature. Results in this study also showed that corals of different ages and of different species did not display the same physiological responses to changes in environmental conditions. Thus, the ability of corals to tolerate salinity and temperature stresses depends on several factors.

Chemotaxis by natural populations of coral reef bacteria.

PubMed

Tout, Jessica; Jeffries, Thomas C; Petrou, Katherina; Tyson, Gene W; Webster, Nicole S; Garren, Melissa; Stocker, Roman; Ralph, Peter J; Seymour, Justin R

2015-08-01

Corals experience intimate associations with distinct populations of marine microorganisms, but the microbial behaviours underpinning these relationships are poorly understood. There is evidence that chemotaxis is pivotal to the infection process of corals by pathogenic bacteria, but this evidence is limited to experiments using cultured isolates under laboratory conditions. We measured the chemotactic capabilities of natural populations of coral-associated bacteria towards chemicals released by corals and their symbionts, including amino acids, carbohydrates, ammonium and dimethylsulfoniopropionate (DMSP). Laboratory experiments, using a modified capillary assay, and in situ measurements, using a novel microfabricated in situ chemotaxis assay, were employed to quantify the chemotactic responses of natural microbial assemblages on the Great Barrier Reef. Both approaches showed that bacteria associated with the surface of the coral species Pocillopora damicornis and Acropora aspera exhibited significant levels of chemotaxis, particularly towards DMSP and amino acids, and that these levels of chemotaxis were significantly higher than that of bacteria inhabiting nearby, non-coral-associated waters. This pattern was supported by a significantly higher abundance of chemotaxis and motility genes in metagenomes within coral-associated water types. The phylogenetic composition of the coral-associated chemotactic microorganisms, determined using 16S rRNA amplicon pyrosequencing, differed from the community in the seawater surrounding the coral and comprised known coral associates, including potentially pathogenic Vibrio species. These findings indicate that motility and chemotaxis are prevalent phenotypes among coral-associated bacteria, and we propose that chemotaxis has an important role in the establishment and maintenance of specific coral-microbe associations, which may ultimately influence the health and stability of the coral holobiont.

Mesophotic coral-reef environments depress the reproduction of the coral Paramontastraea peresi in the Red Sea

NASA Astrophysics Data System (ADS)

Feldman, Bar; Shlesinger, Tom; Loya, Yossi

2018-03-01

With more than 450 studied species, coral reproduction is a well-known research field. However, the vast majority of coral reproduction research has focused exclusively on shallow reefs. The incentive for the present study was: (1) the recent accelerated global degradation of coral reefs; (2) the growing interest in mesophotic coral ecosystems (MCEs; 30-120 m depth) and their potential to serve as a larval source for shallow reefs; and (3) the lack of information on MCE coral reproduction. Here, we compare the reproduction and ecology of the depth-generalist coral Paramontastraea peresi between shallow (5-10 m) and mesophotic (40-45 m) habitats in the Gulf of Eilat/Aqaba, Red Sea. Field surveys were conducted to assess the living cover, abundance, and size frequency distribution of P. peresi. Four to six colonies from each habitat were sampled monthly between April 2015 and January 2017, and the gametogenesis cycles, fecundity, and oocyte sizes were measured. The reproductive cycle in the MCEs was shorter than in the shallow reef. Despite having larger polyps, the mesophotic colonies contained significantly smaller and fewer oocytes per polyp. In spite of the relatively stable environmental conditions of the MCEs, which may contribute to coral survival, scarcity of sunlight is probably a major energetic impediment to investment in reproduction by P. peresi at mesophotic depths. Further intensive reproductive studies in mesophotic reefs are thus required to assess the ability of corals in this environment to reproduce and constitute a larval source for depleted shallow-water reefs.

Coral reef resilience through biodiversity

USGS Publications Warehouse

Rogers, Caroline S.

2013-01-01

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

Corals Form Characteristic Associations with Symbiotic Nitrogen-Fixing Bacteria

PubMed Central

Lema, Kimberley A.; Willis, Bette L.

2012-01-01

The complex symbiotic relationship between corals and their dinoflagellate partner Symbiodinium is believed to be sustained through close associations with mutualistic bacterial communities, though little is known about coral associations with bacterial groups able to fix nitrogen (diazotrophs). In this study, we investigated the diversity of diazotrophic bacterial communities associated with three common coral species (Acropora millepora, Acropora muricata, and Pocillopora damicormis) from three midshelf locations of the Great Barrier Reef (GBR) by profiling the conserved subunit of the nifH gene, which encodes the dinitrogenase iron protein. Comparisons of diazotrophic community diversity among coral tissue and mucus microenvironments and the surrounding seawater revealed that corals harbor diverse nifH phylotypes that differ between tissue and mucus microhabitats. Coral mucus nifH sequences displayed high heterogeneity, and many bacterial groups overlapped with those found in seawater. Moreover, coral mucus diazotrophs were specific neither to coral species nor to reef location, reflecting the ephemeral nature of coral mucus. In contrast, the dominant diazotrophic bacteria in tissue samples differed among coral species, with differences remaining consistent at all three reefs, indicating that coral-diazotroph associations are species specific. Notably, dominant diazotrophs for all coral species were closely related to the bacterial group rhizobia, which represented 71% of the total sequences retrieved from tissue samples. The species specificity of coral-diazotroph associations further supports the coral holobiont model that bacterial groups associated with corals are conserved. Our results suggest that, as in terrestrial plants, rhizobia have developed a mutualistic relationship with corals and may contribute fixed nitrogen to Symbiodinium. PMID:22344646

Light gradients and optical microniches in coral tissues.

PubMed

Wangpraseurt, Daniel; Larkum, Anthony W D; Ralph, Peter J; Kühl, Michael

2012-01-01

Light quantity and quality are among the most important factors determining the physiology and stress response of zooxanthellate corals. Yet, almost nothing is known about the light field that Symbiodinium experiences within their coral host, and the basic optical properties of coral tissue are unknown. We used scalar irradiance microprobes to characterize vertical and lateral light gradients within and across tissues of several coral species. Our results revealed the presence of steep light gradients with photosynthetically available radiation decreasing by about one order of magnitude from the tissue surface to the coral skeleton. Surface scalar irradiance was consistently higher over polyp tissue than over coenosarc tissue in faviid corals. Coral bleaching increased surface scalar irradiance by ~150% (between 500 and 700 nm) relative to a healthy coral. Photosynthesis peaked around 300 μm within the tissue, which corresponded to a zone exhibiting strongest depletion of scalar irradiance. Deeper coral tissue layers, e.g., ~1000 μm into aboral polyp tissues, harbor optical microniches, where only ~10% of the incident irradiance remains. We conclude that the optical microenvironment of corals exhibits strong lateral and vertical gradients of scalar irradiance, which are affected by both tissue and skeleton optical properties. Our results imply that zooxanthellae populations inhabit a strongly heterogeneous light environment and highlight the presence of different optical microniches in corals; an important finding for understanding the photobiology, stress response, as well as the phenotypic and genotypic plasticity of coral symbionts.

Light gradients and optical microniches in coral tissues

PubMed Central

Wangpraseurt, Daniel; Larkum, Anthony W. D.; Ralph, Peter J.; Kühl, Michael

2012-01-01

Light quantity and quality are among the most important factors determining the physiology and stress response of zooxanthellate corals. Yet, almost nothing is known about the light field that Symbiodinium experiences within their coral host, and the basic optical properties of coral tissue are unknown. We used scalar irradiance microprobes to characterize vertical and lateral light gradients within and across tissues of several coral species. Our results revealed the presence of steep light gradients with photosynthetically available radiation decreasing by about one order of magnitude from the tissue surface to the coral skeleton. Surface scalar irradiance was consistently higher over polyp tissue than over coenosarc tissue in faviid corals. Coral bleaching increased surface scalar irradiance by ~150% (between 500 and 700 nm) relative to a healthy coral. Photosynthesis peaked around 300 μm within the tissue, which corresponded to a zone exhibiting strongest depletion of scalar irradiance. Deeper coral tissue layers, e.g., ~1000 μm into aboral polyp tissues, harbor optical microniches, where only ~10% of the incident irradiance remains. We conclude that the optical microenvironment of corals exhibits strong lateral and vertical gradients of scalar irradiance, which are affected by both tissue and skeleton optical properties. Our results imply that zooxanthellae populations inhabit a strongly heterogeneous light environment and highlight the presence of different optical microniches in corals; an important finding for understanding the photobiology, stress response, as well as the phenotypic and genotypic plasticity of coral symbionts. PMID:22969755

Island Formation: Constructing a Coral Island

ERIC Educational Resources Information Center

Austin, Heather; Edd, Amelia

2009-01-01

The process of coral island formation is often difficult for middle school students to comprehend. Coral island formation is a dynamic process, and students should have the opportunity to experience this process in a synergistic context. The authors provide instructional guidelines for constructing a coral island. Students play an interactive role…

A Chemical Approach to Mitigate Coral Bleaching

NASA Astrophysics Data System (ADS)

Marty-Rivera, M.; Yudowski, G.

2016-02-01

Changes in sea surface temperature and irradiance can induce bleaching and increase mortality in corals. Coral bleaching occurs when symbiotic algae living inside the coral is degraded or expelled, reducing the availability of energetic resources. Oxidative stress has been suggested as a possible molecular mechanism triggering bleaching. We hypothesized that reduction of reactive oxygen species (ROS) during stress could mitigate or prevent coral bleaching. We utilized the coral Porites Astreoides as our model to test the effects of two natural antioxidants, catechin and Resveratrol, on thermally induced bleaching. Coral fragments were exposed to four treatments: high temperature (32°C), high temperature plus antioxidants (1μM), ambient temperature (25°C), or ambient temperature (25°C) plus antioxidant for four days. A total of 8 corals were used per treatment. We measured several photobiological parameters, such as maximum quantum yield and light curves to assess the viability of symbiodinium spp. after thermal stress in the presence of antioxidants. Preliminary experiments on a model species, the sea anemone Aiptasia pallida and corals, showed that exposure to antioxidants reduced intracellular levels of ROS. Additionally, antioxidant-treated anemones showed higher photosynthetic efficiency (67%) than those exposed to high-temperature alone.

Carbon and nitrogen isotopic analysis of coral-associated nitrogen in rugose corals of the Middle Devonian, implications for paleoecology and paleoceanography.

NASA Astrophysics Data System (ADS)

Hickey, A. N.; Junium, C. K.; Uveges, B. T.; Ivany, L. C.; Martindale, R. C.

2017-12-01

The Middle Devonian Appalachian Basin of Central New York hosts an extraordinary diversity of well-studied fossil invertebrates within the shallow marine sequences of the Givetian Age, Hamilton Group. Of particular interest are a series of aerially expansive coral beds with diverse assemblages of rugose corals. These well-preserved specimens provide an excellent opportunity to test the feasibility of δ15N and δ13C analyses in rugose corals in an effort to resolve outstanding issues regarding their paleoecology and ontogeny as well environmental dynamics within the Devonian Appalachian Basin. Here we present carbon and nitrogen isotope analyses of the rugose corals Heliophyllum and Siphonophrentis from the Joshua Coral Bed. Corals were cleaned of the host calcareous shale and sonicated sequentially in deionized water and methanol, and then oxidatively cleaned. Cleaned corals were sectioned into 0.5cm billets to obtain enough residual organic material for analysis. The organic content of the corals is low, but nanoEA allows for serial sampling of 5-10 samples per coral. Coral sections were decarbonated and the residual organic material is filtered and dried prior to analysis. Coral organic matter is analyzed in triplicate using nanoEA, which is a cryo-trapping, capillary focusing technique for δ15N and δ13C. The δ15N of organic matter extracted from rugose corals is, on average, enriched by 2-4‰ relative to the bulk nitrogen in the host rock. As well, the δ13C of organic carbon from the corals is 13C-enriched relative to the bulk rock, but to a lesser degree (no more than 1.5‰). Assuming that the bulk rock carbon and nitrogen are largely representative of the long-term primary production background, the modest enrichment is consistent with a trophic effect, and that rugose corals are likely planktivores. In an individual coral, δ15N ranges by 3-4‰ over its length, and when adjusted for trophic enrichment varies around the average δ15N of bulk

Naked-eye sensor for rapid determination of mercury ion.

PubMed

Liu, Jing; Wu, Dapeng; Yan, Xiaohui; Guan, Yafeng

2013-11-15

A naked-eye paper sensor for rapid determination of trace mercury ion in water samples was designed and demonstrated. The mercury-sensing rhodamine B thiolactone was immobilized in silica matrices and the silica matrices were impregnated firmly and uniformly in the filter paper. As water samples flow through the filter paper, the membrane color will change from white to purple red, which could be observed obviously with naked eye, when concentration of mercury ions equals to or exceeds 10nM, the maximum residue level in drinking water recommended by U.S. EPA. The color change can also be recorded by a flatbed scanner and then digitized, reducing the detection limit of Hg(2+) down to 1.2 nM. Moreover, this method is extremely specific for Hg(2+) and shows a high tolerance ratio of interferent coexisting ions. The presence of Na(+) (2 mM), K(+) (2 mM), Fe(3+) (0.1 mM), Zn(2+) (0.1 mM), Mg(2+) (0.1 mM), Ni(2+) (50 μM), Co(2+) (50 μM), Cd(2+) (50 μM), Pb(2+) (50 μM), Cu(2+) (50 μM) and Ag(+) (3.5 μM) did not interfere with the detection of Hg(2+) (25 nM). Finally, the present method was applied in the detection of Hg(2+) in mineral water, tap water and pond water. Copyright © 2013 Elsevier B.V. All rights reserved.

Amorphous calcium carbonate particles form coral skeletons

DOE PAGES

Mass, Tali; Giuffre, Anthony J.; Sun, Chang -Yu; ...

2017-08-28

Do corals form their skeletons by precipitation from solution or by attachment of amorphous precursor particles as observed in other minerals and biominerals? The classical model assumes precipitation in contrast with observed “vital effects,” that is, deviations from elemental and isotopic compositions at thermodynamic equilibrium. Here, we show direct spectromicroscopy evidence in Stylophora pistillata corals that two amorphous precursors exist, one hydrated and one anhydrous amorphous calcium carbonate (ACC); that these are formed in the tissue as 400-nm particles; and that they attach to the surface of coral skeletons, remain amorphous for hours, and finally, crystallize into aragonite (CaCO 3).more » We show in both coral and synthetic aragonite spherulites that crystal growth by attachment of ACC particles is more than 100 times faster than ion-by-ion growth from solution. Fast growth provides a distinct physiological advantage to corals in the rigors of the reef, a crowded and fiercely competitive ecosystem. Corals are affected by warming-induced bleaching and postmortem dissolution, but the finding here that ACC particles are formed inside tissue may make coral skeleton formation less susceptible to ocean acidification than previously assumed. If this is how other corals form their skeletons, perhaps this is how a few corals survived past CO 2 increases, such as the Paleocene–Eocene Thermal Maximum that occurred 56 Mya.« less

Amorphous calcium carbonate particles form coral skeletons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mass, Tali; Giuffre, Anthony J.; Sun, Chang -Yu

Do corals form their skeletons by precipitation from solution or by attachment of amorphous precursor particles as observed in other minerals and biominerals? The classical model assumes precipitation in contrast with observed “vital effects,” that is, deviations from elemental and isotopic compositions at thermodynamic equilibrium. Here, we show direct spectromicroscopy evidence in Stylophora pistillata corals that two amorphous precursors exist, one hydrated and one anhydrous amorphous calcium carbonate (ACC); that these are formed in the tissue as 400-nm particles; and that they attach to the surface of coral skeletons, remain amorphous for hours, and finally, crystallize into aragonite (CaCO 3).more » We show in both coral and synthetic aragonite spherulites that crystal growth by attachment of ACC particles is more than 100 times faster than ion-by-ion growth from solution. Fast growth provides a distinct physiological advantage to corals in the rigors of the reef, a crowded and fiercely competitive ecosystem. Corals are affected by warming-induced bleaching and postmortem dissolution, but the finding here that ACC particles are formed inside tissue may make coral skeleton formation less susceptible to ocean acidification than previously assumed. If this is how other corals form their skeletons, perhaps this is how a few corals survived past CO 2 increases, such as the Paleocene–Eocene Thermal Maximum that occurred 56 Mya.« less

Amorphous calcium carbonate particles form coral skeletons

NASA Astrophysics Data System (ADS)

Mass, Tali; Giuffre, Anthony J.; Sun, Chang-Yu; Stifler, Cayla A.; Frazier, Matthew J.; Neder, Maayan; Tamura, Nobumichi; Stan, Camelia V.; Marcus, Matthew A.; Gilbert, Pupa U. P. A.

2017-09-01

Do corals form their skeletons by precipitation from solution or by attachment of amorphous precursor particles as observed in other minerals and biominerals? The classical model assumes precipitation in contrast with observed “vital effects,” that is, deviations from elemental and isotopic compositions at thermodynamic equilibrium. Here, we show direct spectromicroscopy evidence in Stylophora pistillata corals that two amorphous precursors exist, one hydrated and one anhydrous amorphous calcium carbonate (ACC); that these are formed in the tissue as 400-nm particles; and that they attach to the surface of coral skeletons, remain amorphous for hours, and finally, crystallize into aragonite (CaCO3). We show in both coral and synthetic aragonite spherulites that crystal growth by attachment of ACC particles is more than 100 times faster than ion-by-ion growth from solution. Fast growth provides a distinct physiological advantage to corals in the rigors of the reef, a crowded and fiercely competitive ecosystem. Corals are affected by warming-induced bleaching and postmortem dissolution, but the finding here that ACC particles are formed inside tissue may make coral skeleton formation less susceptible to ocean acidification than previously assumed. If this is how other corals form their skeletons, perhaps this is how a few corals survived past CO2 increases, such as the Paleocene-Eocene Thermal Maximum that occurred 56 Mya.

Amorphous calcium carbonate particles form coral skeletons.

PubMed

Mass, Tali; Giuffre, Anthony J; Sun, Chang-Yu; Stifler, Cayla A; Frazier, Matthew J; Neder, Maayan; Tamura, Nobumichi; Stan, Camelia V; Marcus, Matthew A; Gilbert, Pupa U P A

2017-09-12

Do corals form their skeletons by precipitation from solution or by attachment of amorphous precursor particles as observed in other minerals and biominerals? The classical model assumes precipitation in contrast with observed "vital effects," that is, deviations from elemental and isotopic compositions at thermodynamic equilibrium. Here, we show direct spectromicroscopy evidence in Stylophora pistillata corals that two amorphous precursors exist, one hydrated and one anhydrous amorphous calcium carbonate (ACC); that these are formed in the tissue as 400-nm particles; and that they attach to the surface of coral skeletons, remain amorphous for hours, and finally, crystallize into aragonite (CaCO 3 ). We show in both coral and synthetic aragonite spherulites that crystal growth by attachment of ACC particles is more than 100 times faster than ion-by-ion growth from solution. Fast growth provides a distinct physiological advantage to corals in the rigors of the reef, a crowded and fiercely competitive ecosystem. Corals are affected by warming-induced bleaching and postmortem dissolution, but the finding here that ACC particles are formed inside tissue may make coral skeleton formation less susceptible to ocean acidification than previously assumed. If this is how other corals form their skeletons, perhaps this is how a few corals survived past CO 2 increases, such as the Paleocene-Eocene Thermal Maximum that occurred 56 Mya.

Amorphous calcium carbonate particles form coral skeletons

PubMed Central

Mass, Tali; Giuffre, Anthony J.; Sun, Chang-Yu; Stifler, Cayla A.; Frazier, Matthew J.; Neder, Maayan; Tamura, Nobumichi; Stan, Camelia V.; Marcus, Matthew A.

2017-01-01

Do corals form their skeletons by precipitation from solution or by attachment of amorphous precursor particles as observed in other minerals and biominerals? The classical model assumes precipitation in contrast with observed “vital effects,” that is, deviations from elemental and isotopic compositions at thermodynamic equilibrium. Here, we show direct spectromicroscopy evidence in Stylophora pistillata corals that two amorphous precursors exist, one hydrated and one anhydrous amorphous calcium carbonate (ACC); that these are formed in the tissue as 400-nm particles; and that they attach to the surface of coral skeletons, remain amorphous for hours, and finally, crystallize into aragonite (CaCO3). We show in both coral and synthetic aragonite spherulites that crystal growth by attachment of ACC particles is more than 100 times faster than ion-by-ion growth from solution. Fast growth provides a distinct physiological advantage to corals in the rigors of the reef, a crowded and fiercely competitive ecosystem. Corals are affected by warming-induced bleaching and postmortem dissolution, but the finding here that ACC particles are formed inside tissue may make coral skeleton formation less susceptible to ocean acidification than previously assumed. If this is how other corals form their skeletons, perhaps this is how a few corals survived past CO2 increases, such as the Paleocene–Eocene Thermal Maximum that occurred 56 Mya. PMID:28847944

The efficacy of methylene blue encapsulated in silica nanoparticles compared to naked methylene blue for photodynamic applications.

PubMed

Makhadmeh, Ghaseb Naser; Abdul Aziz, Azlan; Abdul Razak, Khairunisak

2016-05-01

This study analyzed the physical effects of methylene blue (MB) encapsulated within silica nanoparticles (SiNPs) in photodynamic therapy. The optimum concentration of MB needed to destroy red blood cells (RBCs) was determined, and the efficacy of encapsulated MB-SiNPs compared to that of naked MB was verified. The results confirmed the applicability of MB encapsulated in SiNPs on RBCs, and established a relationship between the concentration of the SiNP-encapsulated MB and the time required to rupture 50% of the RBCs (t50). The MB encapsulated in SiNPs exhibited higher efficacy compared to that of naked MB.

Status and progress in coral reef disease research.

PubMed

Weil, Ernesto; Smith, Garriet; Gil-Agudelo, Diego L

2006-03-23

Recent findings on the ecology, etiology and pathology of coral pathogens, host resistance mechanisms, previously unknown disease/syndromes and the global nature of coral reef diseases have increased our concern about the health and future of coral reef communities. Much of what has been discovered in the past 4 years is presented in this special issue. Among the significant findings, the role that various Vibrio species play in coral disease and health, the composition of the 'normal microbiota' of corals, and the possible role of viruses in the disease process are important additions to our knowledge. New information concerning disease resistance and vectors, variation in pathogen composition for both fungal diseases of gorgonians and black band disease across oceans, environmental effects on disease susceptibility and resistance, and temporal and spatial disease variations among different coral species is presented in a number of papers. While the Caribbean may still be the 'disease hot spot' for coral reefs, it is now clear that diseases of coral reef organisms have become a global threat to coral reefs and a major cause of reef deterioration.

Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber)

PubMed Central

Sarko, Diana K.; Leitch, Duncan B.; Catania, Kenneth C.

2013-01-01

The naked mole-rat (Heterocephalus glaber) is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats’ behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors). These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment. PMID:24302898

40 CFR 230.44 - Coral reefs.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or...

40 CFR 230.44 - Coral reefs.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or...

40 CFR 230.44 - Coral reefs.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or...

40 CFR 230.44 - Coral reefs.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or...

40 CFR 230.44 - Coral reefs.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or...

Improved zircon iron corals for the 1990s

DOE Office of Scientific and Technical Information (OSTI.GOV)

Decker, C.

1992-03-01

CIBA-GEIGY/Drakenfeld Colors is dedicated to the research and development of consistent and cost-effective ceramic stains for the whitewares industry. After identifying the trends in color for the 1990s. CIBA-GEIGY/Drakenfeld Colors initiated an extensive R D project to improve zircon ion corals for the whitewares industry. These color trends indicated a need for stronger and cleaner zircon iron corals. This paper discusses the chemistry and crystal structure of zircon iron corals. A historical review of Drakenfeld corals will also be presented. The most recent development in Drakenfeld corals will then be compared to other commercially available zircon iron corals. Taking intomore » consideration these comparisons, conclusions will be drawn suggesting the coral of choice for the 1990s.« less

Nitrogen and photosynthetic function of hermatypic corals. Oxygen exchange of Stylophora pistillata coral under artificial feeding.

PubMed

Leletkin, V A

2005-01-01

The change of Stylophora pistillata coral photosynthetic function (oxygen exchange and biomass of symbionts) under starvation and food enrichment was studied to understand the role of heterotrophy in nitrogen supplements of zooxanthellae. The starvation caused the decrease of frequency of zooxanthellae cells division in 7-10 times. The number of degraded algae cells increased in same proportion and, as a result, the density of zooxanthellae in corals decreased about two times during one-two weeks. Under starvation corals kept their photosynthetic capacity at the level of corals in situ by means of enhancing the zooxanthellae gross photosynthesis. The respiration rate of coral had tendency to increase and the dry mass of polyp tissue to decrease. Under artificial feeding which was following starvation the zooxanthellae density increased in 1.5-2 times, and particular food caused more intensive accumulation of zooxanthellae comparing to dissolved inorganic ammonium. The feeding regime did not affect dry mass of polyp tissue and chlorophyll content as well as respiration and gross productivity of the corals. The conclusion about high effectiveness of particular feeding for supplying symbiotic algae with nitrogen was made and trophic status of zooxanthellae in hospite was determined as unlimited by nitrogen.

Plasmonic ELISA for the ultrasensitive detection of disease biomarkers with the naked eye

NASA Astrophysics Data System (ADS)

de La Rica, Roberto; Stevens, Molly M.

2012-12-01

In resource-constrained countries, affordable methodologies for the detection of disease biomarkers at ultralow concentrations can potentially improve the standard of living. However, current strategies for ultrasensitive detection often require sophisticated instruments that may not be available in laboratories with fewer resources. Here, we circumvent this problem by introducing a signal generation mechanism for biosensing that enables the detection of a few molecules of analyte with the naked eye. The enzyme label of an enzyme-linked immunosorbent assay (ELISA) controls the growth of gold nanoparticles and generates coloured solutions with distinct tonality when the analyte is present. Prostate specific antigen (PSA) and HIV-1 capsid antigen p24 were detected in whole serum at the ultralow concentration of 1 × 10-18 g ml-1. p24 was also detected with the naked eye in the sera of HIV-infected patients showing viral loads undetectable by a gold standard nucleic acid-based test.

Mapping Prevalence and Incidence of Coral Disease in reef-building corals at two Natural Reserves of the Southwest Puerto Rico

NASA Astrophysics Data System (ADS)

Sanchez Viruet, I.; Irizarry-Soto, E.; Ruiz-Valentín, I.

2016-02-01

Coral diseases seems to be the main cause of coral reef decline in the Caribbean. Before the bleaching event of 2005, coral reefs in Puerto Rico were dominated by the reef-building taxa: Orbicella annularis, Porites astreoides, Montastrea cavernosa, Agaricia agaracites and Colpophyllia natans. After the event, live-coral cover significantly declined and more than 90% of the scleractinian corals in the U.S. Virgin Islands and Puerto Rico showed signals of thermal stressors. The prevalence of coral diseases in five reef-building coral (Orbicella annularis, Orbicella franksi, Orbicella faveolata, Porites porites and Pseudiploria strigosa) species was assessed by tagging, photographing, and mapping all diseased and healthy colonies within 10 permanent 40m2 band transects at each inshore and mid-shelf reefs of Belvedere and Punta Guaniquilla Natural Reserves using a random stratified sampling method. Maximum and perpendicular diameter was used to assess coral size using Coral Point Count with Excel Extension. Corals were classified into three size class populations (class I: 0-50cm, class II: 50-100cm and class III: >100 cm). Data was used to develop a GIS-based map containing coral species, size and disease presence. Preliminary results of the inshore area showed a higher disease prevalence in Belvedere natural reserve and for P. strigosa (17.1%) and O. annularis (9.3%). Frequency distribution analysis showed a dominance of O. faveolata at Punta Guaniquilla and Belvedere (127 and 88 individuals respectively). Size class I dominates the distribution of each species within the natural reserves with a higher disease prevalence. Future work include continue prevalence surveys of the outer reef shelf on both natural reserves, monitoring and GIS-based mapping of incidence and resilience through time. This study will help in the assessment of the status of the coral reef of the southwest insular platform.

In situ observations of coral bleaching in the central Saudi Arabian Red Sea during the 2015/2016 global coral bleaching event.

PubMed

Monroe, Alison A; Ziegler, Maren; Roik, Anna; Röthig, Till; Hardenstine, Royale S; Emms, Madeleine A; Jensen, Thor; Voolstra, Christian R; Berumen, Michael L

2018-01-01

Coral bleaching continues to be one of the most devastating and immediate impacts of climate change on coral reef ecosystems worldwide. In 2015, a major bleaching event was declared as the "3rd global coral bleaching event" by the United States National Oceanic and Atmospheric Administration, impacting a large number of reefs in every major ocean. The Red Sea was no exception, and we present herein in situ observations of the status of coral reefs in the central Saudi Arabian Red Sea from September 2015, following extended periods of high temperatures reaching upwards of 32.5°C in our study area. We examined eleven reefs using line-intercept transects at three different depths, including all reefs that were surveyed during a previous bleaching event in 2010. Bleaching was most prevalent on inshore reefs (55.6% ± 14.6% of live coral cover exhibited bleaching) and on shallower transects (41% ± 10.2% of live corals surveyed at 5m depth) within reefs. Similar taxonomic groups (e.g., Agariciidae) were affected in 2015 and in 2010. Most interestingly, Acropora and Porites had similar bleaching rates (~30% each) and similar relative coral cover (~7% each) across all reefs in 2015. Coral genera with the highest levels of bleaching (>60%) were also among the rarest (<1% of coral cover) in 2015. While this bodes well for the relative retention of coral cover, it may ultimately lead to decreased species richness, often considered an important component of a healthy coral reef. The resultant long-term changes in these coral reef communities remain to be seen.

50 CFR 665.169 - Gold coral harvest moratorium.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gold coral harvest moratorium. 665.169... Fisheries § 665.169 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.169 - Gold coral harvest moratorium.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gold coral harvest moratorium. 665.169... Fisheries § 665.169 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.469 - Gold coral harvest moratorium.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gold coral harvest moratorium. 665.469... Archipelago Fisheries § 665.469 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.270 - Gold coral harvest moratorium.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gold coral harvest moratorium. 665.270... Fisheries § 665.270 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.169 - Gold coral harvest moratorium.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gold coral harvest moratorium. 665.169... Fisheries § 665.169 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.469 - Gold coral harvest moratorium.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gold coral harvest moratorium. 665.469... Archipelago Fisheries § 665.469 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.270 - Gold coral harvest moratorium.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gold coral harvest moratorium. 665.270... Fisheries § 665.270 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.469 - Gold coral harvest moratorium.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gold coral harvest moratorium. 665.469... Archipelago Fisheries § 665.469 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.270 - Gold coral harvest moratorium.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gold coral harvest moratorium. 665.270... Fisheries § 665.270 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

Unseen players shape benthic competition on coral reefs.

PubMed

Barott, Katie L; Rohwer, Forest L

2012-12-01

Recent work has shown that hydrophilic and hydrophobic organic matter (OM) from algae disrupts the function of the coral holobiont and promotes the invasion of opportunistic pathogens, leading to coral morbidity and mortality. Here we refer to these dynamics as the (3)DAM [dissolved organic matter (DOM), direct contact, disease, algae and microbes] model. There is considerable complexity in coral-algae interactions; turf algae and macroalgae promote heterotrophic microbial overgrowth of coral, macroalgae also directly harm the corals via hydrophobic OM, whereas crustose coralline algae generally encourage benign microbial communities. In addition, complex flow patterns transport OM and pathogens from algae to downstream corals, and direct algal contact enhances their delivery. These invisible players (microbes, viruses, and OM) are important drivers of coral reefs because they have non-linear responses to disturbances and are the first to change in response to perturbations, providing near real-time trajectories for a coral reef, a vital metric for conservation and restoration. Copyright © 2012 Elsevier Ltd. All rights reserved.

Coral Reef Ecosystems

NASA Astrophysics Data System (ADS)

Yap, Helen T.

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

A change in coral extension rates and stable isotopes after El Niño-induced coral bleaching and regional stress events

NASA Astrophysics Data System (ADS)

Hetzinger, S.; Pfeiffer, M.; Dullo, W.-Chr.; Zinke, J.; Garbe-Schönberg, D.

2016-09-01

Coral reefs are biologically diverse ecosystems threatened with effective collapse under rapid climate change, in particular by recent increases in ocean temperatures. Coral bleaching has occurred during major El Niño warming events, at times leading to the die-off of entire coral reefs. Here we present records of stable isotopic composition, Sr/Ca ratios and extension rate (1940-2004) in coral aragonite from a northern Venezuelan site, where reefs were strongly impacted by bleaching following the 1997-98 El Niño. We assess the impact of past warming events on coral extension rates and geochemical proxies. A marked decrease in coral (Pseudodiploria strigosa) extension rates coincides with a baseline shift to more negative values in oxygen and carbon isotopic composition after 1997-98, while a neighboring coral (Siderastrea siderea) recovered to pre-bleaching extension rates simultaneously. However, other stressors, besides high temperature, might also have influenced coral physiology and geochemistry. Coastal Venezuelan reefs were exposed to a series of extreme environmental fluctuations since the mid-1990s, i.e. upwelling, extreme rainfall and sediment input from landslides. This work provides important new data on the potential impacts of multiple regional stress events on coral isotopic compositions and raises questions about the long-term influence on coral-based paleoclimate reconstructions.

A change in coral extension rates and stable isotopes after El Niño-induced coral bleaching and regional stress events.

PubMed

Hetzinger, S; Pfeiffer, M; Dullo, W-Chr; Zinke, J; Garbe-Schönberg, D

2016-09-13

Coral reefs are biologically diverse ecosystems threatened with effective collapse under rapid climate change, in particular by recent increases in ocean temperatures. Coral bleaching has occurred during major El Niño warming events, at times leading to the die-off of entire coral reefs. Here we present records of stable isotopic composition, Sr/Ca ratios and extension rate (1940-2004) in coral aragonite from a northern Venezuelan site, where reefs were strongly impacted by bleaching following the 1997-98 El Niño. We assess the impact of past warming events on coral extension rates and geochemical proxies. A marked decrease in coral (Pseudodiploria strigosa) extension rates coincides with a baseline shift to more negative values in oxygen and carbon isotopic composition after 1997-98, while a neighboring coral (Siderastrea siderea) recovered to pre-bleaching extension rates simultaneously. However, other stressors, besides high temperature, might also have influenced coral physiology and geochemistry. Coastal Venezuelan reefs were exposed to a series of extreme environmental fluctuations since the mid-1990s, i.e. upwelling, extreme rainfall and sediment input from landslides. This work provides important new data on the potential impacts of multiple regional stress events on coral isotopic compositions and raises questions about the long-term influence on coral-based paleoclimate reconstructions.

Exploring coral microbiome assemblages in the South China Sea.

PubMed

Cai, Lin; Tian, Ren-Mao; Zhou, Guowei; Tong, Haoya; Wong, Yue Him; Zhang, Weipeng; Chui, Apple Pui Yi; Xie, James Y; Qiu, Jian-Wen; Ang, Put O; Liu, Sheng; Huang, Hui; Qian, Pei-Yuan

2018-02-05

Coral reefs are significant ecosystems. The ecological success of coral reefs relies on not only coral-algal symbiosis but also coral-microbial partnership. However, microbiome assemblages in the South China Sea corals remain largely unexplored. Here, we compared the microbiome assemblages of reef-building corals Galaxea (G. fascicularis) and Montipora (M. venosa, M. peltiformis, M. monasteriata) collected from five different locations in the South China Sea using massively-parallel sequencing of 16S rRNA gene and multivariate analysis. The results indicated that microbiome assemblages for each coral species were unique regardless of location and were different from the corresponding seawater. Host type appeared to drive the coral microbiome assemblages rather than location and seawater. Network analysis was employed to explore coral microbiome co-occurrence patterns, which revealed 61 and 80 co-occurring microbial species assembling the Galaxea and Montipora microbiomes, respectively. Most of these co-occurring microbial species were commonly found in corals and were inferred to play potential roles in host nutrient metabolism; carbon, nitrogen, sulfur cycles; host detoxification; and climate change. These findings suggest that the co-occurring microbial species explored might be essential to maintain the critical coral-microbial partnership. The present study provides new insights into coral microbiome assemblages in the South China Sea.

Collection methods and descriptions of coral cores extracted from massive corals in Dry Tortugas National Park, Florida, U.S.A.

USGS Publications Warehouse

Weinzierl, Michael S.; Reich, Christopher D.; Hickey, T. Donald; Bartlett, Lucy A.; Kuffner, Ilsa B.

2016-11-29

Cores from living coral colonies were collected from Dry Tortugas National Park, Florida, U.S.A., to obtain skeletal records of past coral growth and allow geochemical reconstruction of environmental variables during the corals’ centuries-long lifespans. The samples were collected as part of the U.S. Geological Survey Coral Reef Ecosystems Studies project (http:/coastal.er.usgs.gov/crest) that provides science to assist resource managers tasked with the stewardship of coral reef resources. Three colonies each of the coral species Orbicella faveolata and Siderastrea siderea were collected in May 2012 using the methods described herein and as approved under National Park Service scientific collecting permit number DRTO-2012-SCI-0001 and are cataloged under accession number DRTO-353. These coral samples can be used to retroactively construct environmental parameters, including sea-surface temperature, by measuring the elemental composition of the coral skeleton. The cores described here, and others (see http://olga.er.usgs.gov/coreviewer/), can be requested, on loan, for scientific study. Photographic images for each coral in its ocean environment, the coral cores as curated and slabbed, and the X-rays of the slabs can be found in an associated U.S. Geological Survey Data Release.

50 CFR 665.669 - Gold coral harvest moratorium.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gold coral harvest moratorium. 665.669... Island Area Fisheries § 665.669 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.669 - Gold coral harvest moratorium.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gold coral harvest moratorium. 665.669... Island Area Fisheries § 665.669 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

50 CFR 665.669 - Gold coral harvest moratorium.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gold coral harvest moratorium. 665.669... Island Area Fisheries § 665.669 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2013. ...

Petroleum hydrocarbon toxicity to corals: A review.

PubMed

Turner, Nicholas R; Renegar, D Abigail

2017-06-30

The proximity of coral reefs to coastal urban areas and shipping lanes predisposes corals to petroleum pollution from multiple sources. Previous research has evaluated petroleum toxicity to coral using a variety of methodology, including monitoring effects of acute and chronic spills, in situ exposures, and ex situ exposures with both adult and larval stage corals. Variability in toxicant, bioassay conditions, species and other methodological disparities between studies prevents comprehensive conclusions regarding the toxicity of hydrocarbons to corals. Following standardized protocols and quantifying the concentration and composition of toxicant will aid in comparison of results between studies and extrapolation to actual spills. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reef corals bleach to resist stress.

PubMed

Obura, David O

2009-02-01

A rationale is presented here for a primary role of bleaching in regulation of the coral-zooxanthellae symbiosis under conditions of stress. Corals and zooxanthellae have fundamentally different metabolic rates, requiring active homeostasis to limit zooxanthellae production and manage translocated products to maintain the symbiosis. The control processes for homeostasis are compromised by environmental stress, resulting in metabolic imbalance between the symbionts. For the coral-zooxanthella symbiosis the most direct way to minimize metabolic imbalance under stress is to reduce photosynthetic production by zooxanthellae. Two mechanisms have been demonstrated that do this: reduction of the chlorophyll concentration in individual zooxanthellae and reduction of the relative biomass of zooxanthellae. Both mechanisms result in visual whitening of the coral, termed bleaching. Arguments are presented here that bleaching provides the final control to minimize physiological damage from stress as an adversity response to metabolic imbalance. As such, bleaching meets the requirements of a stress response syndrome/general adaptive mechanism that is sensitive to internal states rather than external parameters. Variation in bleaching responses among holobionts reflects genotypic and phenotypic differentiation, allowing evolutionary change by natural selection. Thus, reef corals bleach to resist stress, and thereby have some capacity to adapt to and survive change. The extreme thermal anomalies causing mass coral bleaching worldwide lie outside the reaction norms for most coral-zooxanthellae holobionts, revealing the limitations of bleaching as a control mechanism.

Naked shell singularities on the brane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seahra, Sanjeev S.

By utilizing nonstandard slicings of 5-dimensional Schwarzschild and Schwarzschild-AdS manifolds based on isotropic coordinates, we generate static and spherically-symmetric braneworld spacetimes containing shell-like naked null singularities. For planar slicings, we find that the brane-matter sourcing the solution is a perfect fluid with an exotic equation of state and a pressure singularity where the brane crosses the bulk horizon. From a relativistic point of view, such a singularity is required to maintain matter infinitesimally above the surface of a black hole. From the point of view of the AdS/CFT conjecture, the singular horizon can be seen as one possible quantum correctionmore » to a classical black hole geometry. Various generalizations of planar slicings are also considered for a Ricci-flat bulk, and we find that singular horizons and exotic matter distributions are common features.« less

Applying New Methods to Diagnose Coral Diseases

USGS Publications Warehouse

Kellogg, Christina A.; Zawada, David G.

2009-01-01

Coral disease, one of the major causes of reef degradation and coral death, has been increasing worldwide since the 1970s, particularly in the Caribbean. Despite increased scientific study, simple questions about the extent of disease outbreaks and the causative agents remain unanswered. A component of the U.S. Geological Survey Coral Reef Ecosystem STudies (USGS CREST) project is focused on developing and using new methods to approach the complex problem of coral disease.

Shifting paradigms in restoration of the world's coral reefs.

PubMed

van Oppen, Madeleine J H; Gates, Ruth D; Blackall, Linda L; Cantin, Neal; Chakravarti, Leela J; Chan, Wing Y; Cormick, Craig; Crean, Angela; Damjanovic, Katarina; Epstein, Hannah; Harrison, Peter L; Jones, Thomas A; Miller, Margaret; Pears, Rachel J; Peplow, Lesa M; Raftos, David A; Schaffelke, Britta; Stewart, Kristen; Torda, Gergely; Wachenfeld, David; Weeks, Andrew R; Putnam, Hollie M

2017-09-01

Many ecosystems around the world are rapidly deteriorating due to both local and global pressures, and perhaps none so precipitously as coral reefs. Management of coral reefs through maintenance (e.g., marine-protected areas, catchment management to improve water quality), restoration, as well as global and national governmental agreements to reduce greenhouse gas emissions (e.g., the 2015 Paris Agreement) is critical for the persistence of coral reefs. Despite these initiatives, the health and abundance of corals reefs are rapidly declining and other solutions will soon be required. We have recently discussed options for using assisted evolution (i.e., selective breeding, assisted gene flow, conditioning or epigenetic programming, and the manipulation of the coral microbiome) as a means to enhance environmental stress tolerance of corals and the success of coral reef restoration efforts. The 2014-2016 global coral bleaching event has sharpened the focus on such interventionist approaches. We highlight the necessity for consideration of alternative (e.g., hybrid) ecosystem states, discuss traits of resilient corals and coral reef ecosystems, and propose a decision tree for incorporating assisted evolution into restoration initiatives to enhance climate resilience of coral reefs. © 2017 John Wiley & Sons Ltd.

Re-analysis of previous laboratory phase curves: 2. Connections between opposition effect morphology and spectral features of stony meteorites

NASA Astrophysics Data System (ADS)

Déau, Estelle; Spilker, Linda J.; Flandes, Alberto

2016-07-01

We investigate connections between the opposition phase curves and the spectra from ultraviolet to near infrared wavelengths of stony meteorites. We use two datasets: the reflectance dataset of Capaccioni et al. ([1990] Icarus, 83, 325), which consists of optical phase curves (from 2° to 45°) of 17 stony meteorites (three carbonaceous chondrites, 11 ordinary chondrites, and three achondrites), and the spectral dataset from the RELAB database consisting of near-ultraviolet to near-infrared spectra of the same meteorites. We re-analyzed the first dataset and fit it with two morphological models to derive the amplitude A, the angular width HWHM of the surge and the slope S of the linear part. Our re-analysis confirms that stony meteorites have a non-monotonic behavior of the surge amplitude with albedo, which is also observed in planetary surfaces (Déau et al. [2013] Icarus, 226, 1465), laboratory samples (Nelson et al. [2004] Proc. Lunar Sci. Conf., 35, p. 1089) and asteroids (Belskaya and Shevchenko [2000] Icarus, 147, 94). We find a very strong correlation between the opposition effect morphological parameters and the slope of the spectra between 0.75 μm and 0.95 μm. In particular, we found that meteorites with a positive amplitude-albedo correlation have a positive spectral slope between 0.75 μm and 0.95 μm, while meteorites with a negative amplitude-albedo correlation have a negative spectral slope between 0.75 μm and 0.95 μm. We have ruled out the role of the meteorite samples' macro-properties (grain size, porosity and macroscopic roughness) in the correlations found because these properties were constant during the preparation of the samples. If this hypothesis is correct, this implies that other properties like the composition or the micro-properties (grain inclusions, grain shape or microscopic roughness) could have a preponderant role in the non-monotonic behavior of the surge morphology with albedo at small and moderate phase angles. Further

Coral reefs: Turning back time

NASA Astrophysics Data System (ADS)

Lough, Janice M.

2016-03-01

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

Naked mole-rats maintain healthy skeletal muscle and Complex IV mitochondrial enzyme function into old age

PubMed Central

Stoll, Elizabeth A; Karapavlovic, Nevena; Rosa, Hannah; Woodmass, Michael; Rygiel, Karolina; White, Kathryn; Turnbull, Douglass M; Faulkes, Chris G

2016-01-01

The naked mole-rat (NMR) Heterocephalus glaber is an exceptionally long-lived rodent, living up to 32 years in captivity. This extended lifespan is accompanied by a phenotype of negligible senescence, a phenomenon of very slow changes in the expected physiological characteristics with age. One of the many consequences of normal aging in mammals is the devastating and progressive loss of skeletal muscle, termed sarcopenia, caused in part by respiratory enzyme dysfunction within the mitochondria of skeletal muscle fibers. Here we report that NMRs avoid sarcopenia for decades. Muscle fiber integrity and mitochondrial ultrastructure are largely maintained in aged animals. While mitochondrial Complex IV expression and activity remains stable, Complex I expression is significantly decreased. We show that aged naked mole-rat skeletal muscle tissue contains some mitochondrial DNA rearrangements, although the common mitochondrial DNA deletions associated with aging in human and other rodent skeletal muscles are not present. Interestingly, NMR skeletal muscle fibers demonstrate a significant increase in mitochondrial DNA copy number. These results have intriguing implications for the role of mitochondria in aging, suggesting Complex IV, but not Complex I, function is maintained in the long-lived naked mole rat, where sarcopenia is avoided and healthy muscle function is maintained for decades. PMID:27997359

Deep-sea coral research and technology program: Alaska deep-sea coral and sponge initiative final report

USGS Publications Warehouse

Rooper, Chris; Stone, Robert P.; Etnoyer, Peter; Conrath, Christina; Reynolds, Jennifer; Greene, H. Gary; Williams, Branwen; Salgado, Enrique; Morrison, Cheryl L.; Waller, Rhian G.; Demopoulos, Amanda W.J.

2017-01-01

Deep-sea coral and sponge ecosystems are widespread throughout most of Alaska’s marine waters. In some places, such as the central and western Aleutian Islands, deep-sea coral and sponge resources can be extremely diverse and may rank among the most abundant deep-sea coral and sponge communities in the world. Many different species of fishes and invertebrates are associated with deep-sea coral and sponge communities in Alaska. Because of their biology, these benthic invertebrates are potentially impacted by climate change and ocean acidification. Deepsea coral and sponge ecosystems are also vulnerable to the effects of commercial fishing activities. Because of the size and scope of Alaska’s continental shelf and slope, the vast majority of the area has not been visually surveyed for deep-sea corals and sponges. NOAA’s Deep Sea Coral Research and Technology Program (DSCRTP) sponsored a field research program in the Alaska region between 2012–2015, referred to hereafter as the Alaska Initiative. The priorities for Alaska were derived from ongoing data needs and objectives identified by the DSCRTP, the North Pacific Fishery Management Council (NPFMC), and Essential Fish Habitat-Environmental Impact Statement (EFH-EIS) process.This report presents the results of 15 projects conducted using DSCRTP funds from 2012-2015. Three of the projects conducted as part of the Alaska deep-sea coral and sponge initiative included dedicated at-sea cruises and fieldwork spread across multiple years. These projects were the eastern Gulf of Alaska Primnoa pacifica study, the Aleutian Islands mapping study, and the Gulf of Alaska fish productivity study. In all, there were nine separate research cruises carried out with a total of 109 at-sea days conducting research. The remaining projects either used data and samples collected by the three major fieldwork projects or were piggy-backed onto existing research programs at the Alaska Fisheries Science Center (AFSC).

In situ observations of coral bleaching in the central Saudi Arabian Red Sea during the 2015/2016 global coral bleaching event

PubMed Central

Ziegler, Maren; Roik, Anna; Röthig, Till; Hardenstine, Royale S.; Emms, Madeleine A.; Jensen, Thor; Voolstra, Christian R.; Berumen, Michael L.

2018-01-01

Coral bleaching continues to be one of the most devastating and immediate impacts of climate change on coral reef ecosystems worldwide. In 2015, a major bleaching event was declared as the “3rd global coral bleaching event” by the United States National Oceanic and Atmospheric Administration, impacting a large number of reefs in every major ocean. The Red Sea was no exception, and we present herein in situ observations of the status of coral reefs in the central Saudi Arabian Red Sea from September 2015, following extended periods of high temperatures reaching upwards of 32.5°C in our study area. We examined eleven reefs using line-intercept transects at three different depths, including all reefs that were surveyed during a previous bleaching event in 2010. Bleaching was most prevalent on inshore reefs (55.6% ± 14.6% of live coral cover exhibited bleaching) and on shallower transects (41% ± 10.2% of live corals surveyed at 5m depth) within reefs. Similar taxonomic groups (e.g., Agariciidae) were affected in 2015 and in 2010. Most interestingly, Acropora and Porites had similar bleaching rates (~30% each) and similar relative coral cover (~7% each) across all reefs in 2015. Coral genera with the highest levels of bleaching (>60%) were also among the rarest (<1% of coral cover) in 2015. While this bodes well for the relative retention of coral cover, it may ultimately lead to decreased species richness, often considered an important component of a healthy coral reef. The resultant long-term changes in these coral reef communities remain to be seen. PMID:29672556

Gene expression of corals in response to macroalgal competitors.

PubMed

Shearer, Tonya L; Snell, Terry W; Hay, Mark E

2014-01-01

As corals decline and macroalgae proliferate on coral reefs, coral-macroalgal competition becomes more frequent and ecologically important. Whether corals are damaged by these interactions depends on susceptibility of the coral and traits of macroalgal competitors. Investigating changes in gene expression of corals and their intracellular symbiotic algae, Symbiodinium, in response to contact with different macroalgae provides insight into the biological processes and cellular pathways affected by competition with macroalgae. We evaluated the gene expression profiles of coral and Symbiodinium genes from two confamilial corals, Acropora millepora and Montipora digitata, after 6 h and 48 h of contact with four common macroalgae that differ in their allelopathic potency to corals. Contacts with macroalgae affected different biological pathways in the more susceptible (A. millepora) versus the more resistant (M. digitata) coral. Genes of coral hosts and of their associated Symbiodinium also responded in species-specific and time-specific ways to each macroalga. Changes in number and expression intensity of affected genes were greater after 6 h compared to 48 h of contact and were greater following contact with Chlorodesmis fastigiata and Amphiroa crassa than following contact with Galaxaura filamentosa or Turbinaria conoides. We documented a divergence in transcriptional responses between two confamilial corals and their associated Symbiodinium, as well as a diversity of dynamic responses within each coral species with respect to the species of macroalgal competitor and the duration of exposure to that competitor. These responses included early initiation of immune processes by Montipora, which is more resistant to damage after long-term macroalgal contact. Activation of the immune response by corals that better resist algal competition is consistent with the hypothesis that some macroalgal effects on corals may be mediated by microbial pathogens.

50 CFR 665.469 - Gold coral harvest moratorium.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gold coral harvest moratorium. 665.469... Archipelago Fisheries § 665.469 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2018. [78 FR 32182, May 29, 2013] ...

50 CFR 665.270 - Gold coral harvest moratorium.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gold coral harvest moratorium. 665.270... Fisheries § 665.270 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2018. [78 FR 32182, May 29, 2013] ...

50 CFR 665.469 - Gold coral harvest moratorium.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gold coral harvest moratorium. 665.469... Archipelago Fisheries § 665.469 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2018. [78 FR 32182, May 29, 2013] ...

50 CFR 665.270 - Gold coral harvest moratorium.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gold coral harvest moratorium. 665.270... Fisheries § 665.270 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2018. [78 FR 32182, May 29, 2013] ...

50 CFR 665.169 - Gold coral harvest moratorium.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gold coral harvest moratorium. 665.169... Fisheries § 665.169 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2018. [78 FR 32182, May 29, 2013] ...

50 CFR 665.169 - Gold coral harvest moratorium.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gold coral harvest moratorium. 665.169... Fisheries § 665.169 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2018. [78 FR 32182, May 29, 2013] ...

Snake bite: coral snakes.

PubMed

Peterson, Michael E

2006-11-01

North American coral snakes are distinctively colored beginning with a black snout and an alternating pattern of black, yellow, and red. They have fixed front fangs and a poorly developed system for venom delivery, requiring a chewing action to inject the venom. The severity of a coral snake bite is related to the volume of venom injected and the size of the victim. The length of the snake correlates positively with the snakes venom yield. Coral snake venom is primarily neurotoxic with little local tissue reaction or pain at the bite site. The net effect of the neurotoxins is a curare like syndrome. In canine victims there have been reports of marked hemolysis with severe anemia and hemoglobinuria. The onset of clinical signs may be delayed for as much as 10 to 18 hours. The victim begins to have alterations in mental status and develops generalized weakness and muscle fasciculations. Progression to paralysis of the limbs and respiratory muscles then follows. The best flied response to coral snake envenomation is rapid transport to a veterinary medical facility capable of 24 hour critical care and assisted ventilation. First aid treatment advocated in Australia for Elapid bites is the immediate use of a compression bandage. The victim should be hospitalized for a minimum of 48 hours for continuous monitoring. The only definitive treatment for coral snake envenomation is the administration of antivenin (M. fulvius). Once clinical signs of coral snake envenomation become manifest they progress with alarming rapidity and are difficult to reverse. If antivenin is not available or if its administration is delayed, supportive care includes respiratory support. Assisted mechanical ventilation can be used but may have to be employed for up to 48 to 72 hours.

Delayed coral recovery in a warming ocean.

PubMed

Osborne, Kate; Thompson, Angus A; Cheal, Alistair J; Emslie, Michael J; Johns, Kerryn A; Jonker, Michelle J; Logan, Murray; Miller, Ian R; Sweatman, Hugh P A

2017-09-01

Climate change threatens coral reefs across the world. Intense bleaching has caused dramatic coral mortality in many tropical regions in recent decades, but less obvious chronic effects of temperature and other stressors can be equally threatening to the long-term persistence of diverse coral-dominated reef systems. Coral reefs persist if coral recovery rates equal or exceed average rates of mortality. While mortality from acute destructive events is often obvious and easy to measure, estimating recovery rates and investigating the factors that influence them requires long-term commitment. Coastal development is increasing in many regions, and sea surface temperatures are also rising. The resulting chronic stresses have predictable, adverse effects on coral recovery, but the lack of consistent long-term data sets has prevented measurement of how much coral recovery rates are actually changing. Using long-term monitoring data from 47 reefs spread over 10 degrees of latitude on Australia's Great Barrier Reef (GBR), we used a modified Gompertz equation to estimate coral recovery rates following disturbance. We compared coral recovery rates in two periods: 7 years before and 7 years after an acute and widespread heat stress event on the GBR in 2002. From 2003 to 2009, there were few acute disturbances in the region, allowing us to attribute the observed shortfall in coral recovery rates to residual effects of acute heat stress plus other chronic stressors. Compared with the period before 2002, the recovery of fast-growing Acroporidae and of "Other" slower growing hard corals slowed after 2002, doubling the time taken for modest levels of recovery. If this persists, recovery times will be increasing at a time when acute disturbances are predicted to become more frequent and intense. Our study supports the need for management actions to protect reefs from locally generated stresses, as well as urgent global action to mitigate climate change. © 2017 John Wiley & Sons

Diversity and Evolution of Coral Fluorescent Proteins

PubMed Central

Alieva, Naila O.; Konzen, Karen A.; Field, Steven F.; Meleshkevitch, Ella A.; Hunt, Marguerite E.; Beltran-Ramirez, Victor; Miller, David J.; Wiedenmann, Jörg; Salih, Anya; Matz, Mikhail V.

2008-01-01

GFP-like fluorescent proteins (FPs) are the key color determinants in reef-building corals (class Anthozoa, order Scleractinia) and are of considerable interest as potential genetically encoded fluorescent labels. Here we report 40 additional members of the GFP family from corals. There are three major paralogous lineages of coral FPs. One of them is retained in all sampled coral families and is responsible for the non-fluorescent purple-blue color, while each of the other two evolved a full complement of typical coral fluorescent colors (cyan, green, and red) and underwent sorting between coral groups. Among the newly cloned proteins are a “chromo-red” color type from Echinopora forskaliana (family Faviidae) and pink chromoprotein from Stylophora pistillata (Pocilloporidae), both evolving independently from the rest of coral chromoproteins. There are several cyan FPs that possess a novel kind of excitation spectrum indicating a neutral chromophore ground state, for which the residue E167 is responsible (numeration according to GFP from A. victoria). The chromoprotein from Acropora millepora is an unusual blue instead of purple, which is due to two mutations: S64C and S183T. We applied a novel probabilistic sampling approach to recreate the common ancestor of all coral FPs as well as the more derived common ancestor of three main fluorescent colors of the Faviina suborder. Both proteins were green such as found elsewhere outside class Anthozoa. Interestingly, a substantial fraction of the all-coral ancestral protein had a chromohore apparently locked in a non-fluorescent neutral state, which may reflect the transitional stage that enabled rapid color diversification early in the history of coral FPs. Our results highlight the extent of convergent or parallel evolution of the color diversity in corals, provide the foundation for experimental studies of evolutionary processes that led to color diversification, and enable a comparative analysis of structural

Thermal tolerances of reef corals in the Gulf: a review of the potential for increasing coral survival and adaptation to climate change through assisted translocation.

PubMed

Coles, Steve L; Riegl, Bernhard M

2013-07-30

Corals in the Gulf withstand summer temperatures up to 10 °C higher than corals elsewhere and have recovered from extreme temperature events in 10 years or less. This heat-tolerance of Gulf corals has positive implications for the world's coral populations to adapt to increasing water temperatures. However, survival of Gulf corals has been severely tested by 35-37 °C temperatures five times in the last 15 years, each time causing extensive coral bleaching and mortality. Anticipated future temperature increases may therefore challenge survival of already highly stressed Gulf corals. Previously proposed translocation of Gulf corals to introduce temperature-adapted corals outside of the Gulf is assessed and determined to be problematical, and to be considered a tool of last resort. Coral culture and transplantation within the Gulf is feasible for helping maintain coral species populations and preserving genomes and adaptive capacities of Gulf corals that are endangered by future thermal stress events. Copyright © 2012 Elsevier Ltd. All rights reserved.

The giant Mauritanian cold-water coral mound province: Oxygen control on coral mound formation

NASA Astrophysics Data System (ADS)

Wienberg, Claudia; Titschack, Jürgen; Freiwald, André; Frank, Norbert; Lundälv, Tomas; Taviani, Marco; Beuck, Lydia; Schröder-Ritzrau, Andrea; Krengel, Thomas; Hebbeln, Dierk

2018-04-01

The largest coherent cold-water coral (CWC) mound province in the Atlantic Ocean exists along the Mauritanian margin, where up to 100 m high mounds extend over a distance of ∼400 km, arranged in two slope-parallel chains in 400-550 m water depth. Additionally, CWCs are present in the numerous submarine canyons with isolated coral mounds being developed on some canyon flanks. Seventy-seven Uranium-series coral ages were assessed to elucidate the timing of CWC colonisation and coral mound development along the Mauritanian margin for the last ∼120,000 years. Our results show that CWCs were present on the mounds during the Last Interglacial, though in low numbers corresponding to coral mound aggradation rates of 16 cm kyr-1. Most prolific periods for CWC growth are identified for the last glacial and deglaciation, resulting in enhanced mound aggradation (>1000 cm kyr-1), before mound formation stagnated along the entire margin with the onset of the Holocene. Until today, the Mauritanian mounds are in a dormant state with only scarce CWC growth. In the canyons, live CWCs are abundant since the Late Holocene at least. Thus, the canyons may serve as a refuge to CWCs potentially enabling the observed modest re-colonisation pulse on the mounds along the open slope. The timing and rate of the pre-Holocene coral mound aggradation, and the cessation of mound formation varied between the individual mounds, which was likely the consequence of vertical/lateral changes in water mass structure that placed the mounds near or out of oxygen-depleted waters, respectively.

Antibacterial Activity of Hawaiian Corals: Possible Protection from Disease?

NASA Astrophysics Data System (ADS)

Gochfeld, D. J.; Aeby, G. S.; Miller, J. D.

2006-12-01

Reports of coral diseases in the Caribbean have appeared with increasing frequency over the past two decades; however, records of coral diseases in the Pacific have lagged far behind. Recent surveys of coral disease in the Hawaiian Islands indicate relatively low, but consistent, levels of disease throughout the inhabited Main and uninhabited Northwestern Hawaiian Islands, and demonstrate variation in levels of disease among the major genera of Hawaiian corals. Although little is known about immune defense to disease in corals, one potential mechanism of defense is the production of antimicrobial compounds that protect corals from pathogens. A preliminary survey of antibacterial chemical defenses among three dominant species of Hawaiian corals was undertaken. Crude aqueous extracts of Porites lobata, Pocillopora meandrina and Montipora capitata were tested against nine strains of bacteria in a growth inhibition assay. Inhibitory extracts were further tested to determine whether their effects were cytostatic or cytotoxic. The bacteria selected included known coral pathogens, potential marine pathogens found in human waste and strains previously identified from the surfaces of Hawaiian corals. Extracts from all three species of coral exhibited a high degree of antibacterial activity, but also a high degree of selectivity against different bacterial strains. In addition, some extracts were stimulatory to some bacteria. In addition to interspecific variability, extracts also exhibited intraspecific variability, both within and between sites. Hawaiian corals have significant antibacterial activity, which may explain the relatively low prevalence of disease in these corals; however, further characterization of pathogens specifically responsible for disease in Hawaiian corals is necessary before we can conclude that antibacterial activity protects Hawaiian corals from disease.

Large-amplitude internal waves sustain coral health during thermal stress

NASA Astrophysics Data System (ADS)

Schmidt, Gertraud M.; Wall, Marlene; Taylor, Marc; Jantzen, Carin; Richter, Claudio

2016-09-01

Ocean warming is a major threat for coral reefs causing widespread coral bleaching and mortality. Potential refugia are thus crucial for coral survival. Exposure to large-amplitude internal waves (LAIW) mitigated heat stress and ensured coral survival and recovery during and after an extreme heat anomaly. The physiological status of two common corals, Porites lutea and Pocillopora meandrina, was monitored in host and symbiont traits, in response to LAIW-exposure throughout the unprecedented 2010 heat anomaly in the Andaman Sea. LAIW-exposed corals of both species survived and recovered, while LAIW-sheltered corals suffered partial and total mortality in P. lutea and P. meandrina, respectively. LAIW are ubiquitous in the tropics and potentially generate coral refuge areas. As thermal stress to corals is expected to increase in a warming ocean, the mechanisms linking coral bleaching to ocean dynamics will be crucial to predict coral survival on a warming planet.

Coral-the world's most diverse symbiotic ecosystem.

PubMed

Blackall, Linda L; Wilson, Bryan; van Oppen, Madeleine J H

2015-11-01

Zooxanthellate corals (i.e. those harbouring Symbiodinium) are the main builders of the world's shallow-water marine coral reefs. They represent intimate diverse symbioses between coral animals, single-celled photosynthetic dinoflagellates (Symbiodinium spp.), other microscopic eukaryotes, prokaryotes and viruses. Crabs and other crustaceans, worms, sponges, bivalves and hydrozoans, fishes, sea urchins, octopuses and sea stars are itinerant members of these 'rainforests of the sea'. This review focuses on the biodiversity of scleractinian coral animals and their best studied microscopic epi- and endosymbionts. In relation to coral-associated species diversity, Symbiodinium internal transcribed spacer region sequence types tally 10(2) -10(3) or up to ~15 different operational taxonomic units (OTUs, or putative species at the 97% sequence identity level; this cut-off was chosen based on intragenomic sequence diversity observed in monoclonal cultures) and prokaryotes (mostly bacterial) total 10(2) -10(4) OTUs. We analysed all publically accessible 16S rRNA gene sequence data and found Gammaproteobacteria were extremely abundant, followed by Alphaproteobacteria. Notably, Archaea were poorly represented and 'unassigned OTUs' were abundant in data generated by high-throughput DNA sequencing studies of corals. We outline and compare model systems that could be used in future studies of the coral holobiont. In our future directions, we recommend a global coral sampling effort including substantial attention being paid to method of coral tissue acquisition, which compartments (mucus, tissue, skeleton) to explore, broadening the holobiont members considered and linking biodiversity with functional investigations. © 2015 John Wiley & Sons Ltd.

50 CFR 665.669 - Gold coral harvest moratorium.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gold coral harvest moratorium. 665.669... Island Area Fisheries § 665.669 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2018. [78 FR 32182, May 29, 2013] ...

50 CFR 665.669 - Gold coral harvest moratorium.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gold coral harvest moratorium. 665.669... Island Area Fisheries § 665.669 Gold coral harvest moratorium. Fishing for, taking, or retaining any gold coral in any precious coral permit area is prohibited through June 30, 2018. [78 FR 32182, May 29, 2013] ...

Registration of tufted-naked seed in upland cotton germplasm 9023n4t

USDA-ARS?s Scientific Manuscript database

A naked-tufted mutant called 9023n4t (PI 667553) was developed from the cultivar SC 9023 (Gossypium hirsutum L.) through chemical mutagenesis. This germplasm was developed by the Department of Plant and Soil Science, Texas Tech University and released in April, 2013. This mutant is quite unique sinc...

INDICATORS OF UV EXPOSURE IN CORALS: RELEVANCE TO GLOBAL CLIMATE CHANGE AND CORAL BLEACHING

EPA Science Inventory

Increased exposure to solar UV radiation and elevated water temperatures are believed to play a role in the bleaching of corals. To provide additional tools for evaluating the role of UV radiation, we have examined UV-specific effects in coral and have characterized factors that ...

Viruses: agents of coral disease?

PubMed

Davy, S K; Burchett, S G; Dale, A L; Davies, P; Davy, J E; Muncke, C; Hoegh-Guldberg, O; Wilson, W H

2006-03-23

The potential role of viruses in coral disease has only recently begun to receive attention. Here we describe our attempts to determine whether viruses are present in thermally stressed corals Pavona danai, Acropora formosa and Stylophora pistillata and zoanthids Zoanthus sp., and their zooxanthellae. Heat-shocked P. danai, A. formosa and Zoanthus sp. all produced numerous virus-like particles (VLPs) that were evident in the animal tissue, zooxanthellae and the surrounding seawater; VLPs were also seen around heat-shocked freshly isolated zooxanthellae (FIZ) from P. danai and S. pistillata. The most commonly seen VLPs were tail-less, hexagonal and about 40 to 50 nm in diameter, though a diverse range of other VLP morphotypes (e.g. rounded, rod-shaped, droplet-shaped, filamentous) were also present around corals. When VLPs around heat-shocked FIZ from S. pistillata were added to non-stressed FIZ from this coral, they resulted in cell lysis, suggesting that an infectious agent was present; however, analysis with transmission electron microscopy provided no clear evidence of viral infection. The release of diverse VLPs was again apparent when flow cytometry was used to enumerate release by heat-stressed A. formosa nubbins. Our data support the infection of reef corals by viruses, though we cannot yet determine the precise origin (i.e. coral, zooxanthellae and/or surface microbes) of the VLPs seen. Furthermore, genome sequence data are required to establish the presence of viruses unequivocally.

COral Mortality and Bleaching Output (COMBO) Model

EPA Science Inventory

COMBO estimates the effects of climate change and ocean acidification on coral reefs at local-to-regional scales. The COMBO model calculates the impacts to coral reefs (change in coral cover) from changes in average SST and CO2 concentrations, and from high temperature mortality ...

CORAL REEF BIOLOGICAL CRITERIA: USING THE CLEAN ...

EPA Pesticide Factsheets

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

Lipid biomarkers of thermal stress in scleractinian corals

NASA Astrophysics Data System (ADS)

Kneeland, J. M.; Hughen, K.; Cervino, J.; Eglinton, T. I.; Bartels, E.

2007-12-01

Lipid content and fatty acid profiles of corals and their symbiotic dinoflagellates are known to vary in response to heat stress and bleaching. To develop lipid biomarkers of heat stress and bleaching response in scleractinian corals, clones of Symbiodinium algae of clade subtypes C1 and D1 were cultured under a range of temperatures. The predominant lipids produced are palmitic (C16) and stearic (C18) saturated fatty acids and their unsaturated analogs. Other important compounds included a C22 penta-unsaturated fatty acid, which is thought to be a specific dinoflagellate marker, and a variety of sterols. Analysis of lipids extracted from coral skeleton indicated that palmitic and stearic acids were the most abundant compounds. The amount of unsaturated C16 and C18 fatty acids in coral skeleton relative to the saturated versions of those acids was much lower in coral skeleton than in the zooxanthellae tissue. This could indicate the incorporation of lipids from outside the coral host-symbiont system into the coral aragonite, or it could reflect diagenesis. A comparison between the lipids found in cloned zooxanthellae, coral tissue, and aragonitic skeleton will be presented to assess the usefulness of lipid biomarkers as indicators of temperature stress on corals.

Analysis of the coral associated bacterial community structures in healthy and diseased corals from off-shore of southern Taiwan.

PubMed

Chiou, Shu-Fen; Kuo, Jimmy; Wong, Tit-Yee; Fan, Tung-Yung; Tew, Kwee Siong; Liu, Jong-Kang

2010-07-01

The methods of denaturing gradient gel electrophoresis (DGGE) and DNA sequencing were used to analyze the ribotypes of microbial communities associated with corals. Both healthy and diseased coral of different species were collected at three locations off the southern coast of Taiwan. Ribotyping results suggested that the microbial communities were diverse. The microbial community profiles, even among the same species of corals from different geographical locations, differ significantly. The coral-associated bacterial communities contain many bacteria common to the habitants of various invertebrates. However, some bacteria were unexpected. The presence of some unusual species, such as Staphylococcus, Clostridium and Legionella, associated with corals that were likely the results of human activities. Human activities, such as thermal pollution from the nearby nuclear plant, active fishing and tourism industries in the region might have all contributed to the change in bacterial communities and the death of coral colonies around the region.

The versatile nature of coral-associated viruses.

PubMed

Bettarel, Yvan; Bouvier, Thierry; Nguyen, Hanh Kim; Thu, Pham The

2015-10-01

A recent hypothesis considers that many coral pathologies are the result of a sudden structural alteration of the epibiotic bacterial communities in response to environmental disturbances. However, the ecological mechanisms that lead to shifts in their composition are still unclear. In the ocean, viruses represent a major bactericidal agent but little is known on their occurrence within the coral holobiont. Recent reports have revealed that viruses are abundant and diversified within the coral mucus and therefore could be decisive for coral health. However, their mode of action is still unknown, and there is now an urgent need to shed light on the nature of the relationships they might have with the other prokaryotic and eukaryotic members of the holobiont. In this opinion letter, we are putting forward the hypothesis that coral-associated viruses (mostly bacterial and algal viruses), depending on the environmental conditions might either reinforce coral stability or conversely fasten their decline. We propose that these processes are presumably based on an environmentally driven shift in infection strategies allowing viruses to regulate, circumstantially, both coral symbionts (bacteria or Symbiodinium) and surrounding pathogens. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

Three methods for isolating viable anthozoan endoderm cells with their intracellular symbiotic dinoflagellates

NASA Astrophysics Data System (ADS)

Gates, R. D.; Muscatine, L.

1992-09-01

Three maceration methods are described for the isolation of single endoderm cells from marine cnidarians. Two are enzymatic treatments suitable for fleshy anthozoans such as sea anemones and zoanthids. The third employs calcium free sea water and is suitable for stony corals. The viability and morphology of the endoderm cells is described using fluorogenic dyes and scanning and transmission electron microscopy.

CORAL DISEASE & HEALTH CONSORTIUM; PARTNERS FOR PRESERVATION

EPA Science Inventory

Presented at EMAP Symposium 2001: Coastal Monitoring Through Partnerships, 24-27 April 2001, Pensacola Beach, FL.

The Coral Disease and Health Consortium (CDHC) was one recommendation to the U.S. Coral Reef Task Force (CRTF), to conserve the coral reef ecosystems of the U...

Permanent 'phase shifts' or reversible declines in coral cover? Lack of recovery of two coral reefs in St. John, US Virgin Islands

USGS Publications Warehouse

Rogers, C.S.; Miller, J.

2006-01-01

Caribbean coral reefs have changed dramatically in the last 3 to 4 decades, with significant loss of coral cover and increases in algae. Here we present trends in benthic cover from 1989 to 2003 at 2 reefs (Lameshur Reef and Newfound Reef) off St. John, US Virgin Islands (USVI). Coral cover has declined in the fore-reef zones at both sites, and no recovery is evident. At Lameshur Reef, Hurricane Hugo (1989) caused significant physical damage and loss of coral. We suggest that macroalgae rapidly colonized new substrate made available by this storm and have hindered or prevented growth of adult corals, as well as settlement and survival of new coral recruits. Overfishing of herbivorous fishes in the USVI and loss of shelter for these fishes because of major storms has presumably reduced the levels of herbivory that formerly controlled algal abundance. Coral cover declined at Newfound Reef from 1999 to 2000, most likely because of coral diseases. The trends that we have documented, loss of coral followed by no evidence of recovery, appear similar to findings from other studies in the Caribbean. We need to focus on functional shifts in the resilience of coral reefs that result in their inability to recover from natural and human-caused stressors. ?? Inter-Research 2006.

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

NASA Astrophysics Data System (ADS)

Li, Angang; Reidenbach, Matthew A.

2014-09-01

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

Coral Settlement on a Highly Disturbed Equatorial Reef System

PubMed Central

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

2015-01-01

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

Coral settlement on a highly disturbed equatorial reef system.

PubMed

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

2015-01-01

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

Bacterial community dynamics are linked to patterns of coral heat tolerance

NASA Astrophysics Data System (ADS)

Ziegler, Maren; Seneca, Francois O.; Yum, Lauren K.; Palumbi, Stephen R.; Voolstra, Christian R.

2017-02-01

Ocean warming threatens corals and the coral reef ecosystem. Nevertheless, corals can be adapted to their thermal environment and inherit heat tolerance across generations. In addition, the diverse microbes that associate with corals have the capacity for more rapid change, potentially aiding the adaptation of long-lived corals. Here, we show that the microbiome of reef corals is different across thermally variable habitats and changes over time when corals are reciprocally transplanted. Exposing these corals to thermal bleaching conditions changes the microbiome for heat-sensitive corals, but not for heat-tolerant corals growing in habitats with natural high heat extremes. Importantly, particular bacterial taxa predict the coral host response in a short-term heat stress experiment. Such associations could result from parallel responses of the coral and the microbial community to living at high natural temperatures. A competing hypothesis is that the microbial community and coral heat tolerance are causally linked.

Vortical ciliary flows actively enhance mass transport in reef corals.

PubMed

Shapiro, Orr H; Fernandez, Vicente I; Garren, Melissa; Guasto, Jeffrey S; Debaillon-Vesque, François P; Kramarsky-Winter, Esti; Vardi, Assaf; Stocker, Roman

2014-09-16

The exchange of nutrients and dissolved gasses between corals and their environment is a critical determinant of the growth of coral colonies and the productivity of coral reefs. To date, this exchange has been assumed to be limited by molecular diffusion through an unstirred boundary layer extending 1-2 mm from the coral surface, with corals relying solely on external flow to overcome this limitation. Here, we present direct microscopic evidence that, instead, corals can actively enhance mass transport through strong vortical flows driven by motile epidermal cilia covering their entire surface. Ciliary beating produces quasi-steady arrays of counterrotating vortices that vigorously stir a layer of water extending up to 2 mm from the coral surface. We show that, under low ambient flow velocities, these vortices, rather than molecular diffusion, control the exchange of nutrients and oxygen between the coral and its environment, enhancing mass transfer rates by up to 400%. This ability of corals to stir their boundary layer changes the way that we perceive the microenvironment of coral surfaces, revealing an active mechanism complementing the passive enhancement of transport by ambient flow. These findings extend our understanding of mass transport processes in reef corals and may shed new light on the evolutionary success of corals and coral reefs.

Chemically rich seaweeds poison corals when not controlled by herbivores

PubMed Central

Rasher, Douglas B.; Hay, Mark E.

2010-01-01

Coral reefs are in dramatic global decline, with seaweeds commonly replacing corals. It is unclear, however, whether seaweeds harm corals directly or colonize opportunistically following their decline and then suppress coral recruitment. In the Caribbean and tropical Pacific, we show that, when protected from herbivores, ~40 to 70% of common seaweeds cause bleaching and death of coral tissue when in direct contact. For seaweeds that harmed coral tissues, their lipid-soluble extracts also produced rapid bleaching. Coral bleaching and mortality was limited to areas of direct contact with seaweeds or their extracts. These patterns suggest that allelopathic seaweed-coral interactions can be important on reefs lacking herbivore control of seaweeds, and that these interactions involve lipid-soluble metabolites transferred via direct contact. Seaweeds were rapidly consumed when placed on a Pacific reef protected from fishing but were left intact or consumed at slower rates on an adjacent fished reef, indicating that herbivory will suppress seaweeds and lower frequency of allelopathic damage to corals if reefs retain intact food webs. With continued removal of herbivores from coral reefs, seaweeds are becoming more common. This occurrence will lead to increasing frequency of seaweed-coral contacts, increasing allelopathic suppression of remaining corals, and continuing decline of reef corals. PMID:20457927

Chemically rich seaweeds poison corals when not controlled by herbivores.

PubMed

Rasher, Douglas B; Hay, Mark E

2010-05-25

Coral reefs are in dramatic global decline, with seaweeds commonly replacing corals. It is unclear, however, whether seaweeds harm corals directly or colonize opportunistically following their decline and then suppress coral recruitment. In the Caribbean and tropical Pacific, we show that, when protected from herbivores, approximately 40 to 70% of common seaweeds cause bleaching and death of coral tissue when in direct contact. For seaweeds that harmed coral tissues, their lipid-soluble extracts also produced rapid bleaching. Coral bleaching and mortality was limited to areas of direct contact with seaweeds or their extracts. These patterns suggest that allelopathic seaweed-coral interactions can be important on reefs lacking herbivore control of seaweeds, and that these interactions involve lipid-soluble metabolites transferred via direct contact. Seaweeds were rapidly consumed when placed on a Pacific reef protected from fishing but were left intact or consumed at slower rates on an adjacent fished reef, indicating that herbivory will suppress seaweeds and lower frequency of allelopathic damage to corals if reefs retain intact food webs. With continued removal of herbivores from coral reefs, seaweeds are becoming more common. This occurrence will lead to increasing frequency of seaweed-coral contacts, increasing allelopathic suppression of remaining corals, and continuing decline of reef corals.

Resilience potential of an Indian Ocean reef: an assessment through coral recruitment pattern and survivability of juvenile corals to recurrent stress events.

PubMed

Manikandan, Balakrishnan; Ravindran, Jeyaraman; Vidya, Pottekkatt Jayabalan; Shrinivasu, Selvaraju; Manimurali, Rajagopal; Paramasivam, Kaliyaperumal

2017-05-01

Coral reefs are degraded by the synergistic action of climate and anthropogenic stressors. Coral cover in the Palk Bay reef at the northern Indian Ocean largely declined in the past decade due to frequent bleaching events, tsunami and increased fishing activities. In this study, we carried out a comparative assessment to assess the differences in the recovery and resilience of three spatially distant reefs viz. Vedhalai, Mandapam and Pamban along Palk Bay affected by moderate, severe and low fishing pressure respectively. The assessment was based on the juvenile coral recruitment pattern and its survivability combined with availability of hard substratum, live coral cover and herbivore reef fish stock. The Vedhalai reef has the highest coral cover (14.6 ± 6.3%), and ≥90% of the live corals in Vedhalai and Mandapam were affected by turf algal overgrowth. The density of herbivore reef fish was low in Vedhalai and Mandapam reefs compared to the Pamban reef with relatively few grazing species. The juvenile coral diversity and density were high in the Pamban reef and low in Vedhalai and Mandapam reefs despite high hard substratum cover. In total, 22 species of juvenile corals of 10 genera were recorded in Palk Bay. Comparison of the species diversity of juvenile corals with adult ones suggested that the Pamban reef is connected with other distant reefs whereas Vedhalai and Mandapam reefs were self-seeded. There was no statistically significant difference in the survivability of juvenile corals between the study sites, and in total, ≥90% of the juvenile corals survived the high sedimentation stress triggered by the northeast monsoon and bleaching stress that occurred recurrently. Our results indicated that the human activities indirectly affected the juvenile coral recruitment by degrading the live coral cover and contributed to the spatial variation in the recovery and resilience of the Palk Bay reef. Low species diversity of the juvenile corals will increase the

Transcriptomes and expression profiling of deep-sea corals from the Red Sea provide insight into the biology of azooxanthellate corals.

PubMed

Yum, Lauren K; Baumgarten, Sebastian; Röthig, Till; Roder, Cornelia; Roik, Anna; Michell, Craig; Voolstra, Christian R

2017-07-25

Despite the importance of deep-sea corals, our current understanding of their ecology and evolution is limited due to difficulties in sampling and studying deep-sea environments. Moreover, a recent re-evaluation of habitat limitations has been suggested after characterization of deep-sea corals in the Red Sea, where they live at temperatures of above 20 °C at low oxygen concentrations. To gain further insight into the biology of deep-sea corals, we produced reference transcriptomes and studied gene expression of three deep-sea coral species from the Red Sea, i.e. Dendrophyllia sp., Eguchipsammia fistula, and Rhizotrochus typus. Our analyses suggest that deep-sea coral employ mitochondrial hypometabolism and anaerobic glycolysis to manage low oxygen conditions present in the Red Sea. Notably, we found expression of genes related to surface cilia motion that presumably enhance small particle transport rates in the oligotrophic deep-sea environment. This is the first study to characterize transcriptomes and in situ gene expression for deep-sea corals. Our work offers several mechanisms by which deep-sea corals might cope with the distinct environmental conditions present in the Red Sea As such, our data provide direction for future research and further insight to organismal response of deep-sea coral to environmental change and ocean warming.

Life histories predict coral community disassembly under multiple stressors.

PubMed

Darling, Emily S; McClanahan, Timothy R; Côté, Isabelle M

2013-06-01

Climate change is reshaping biological communities against a background of existing human pressure. Evaluating the impacts of multiple stressors on community dynamics can be particularly challenging in species-rich ecosystems, such as coral reefs. Here, we investigate whether life-history strategies and cotolerance to different stressors can predict community responses to fishing and temperature-driven bleaching using a 20-year time series of coral assemblages in Kenya. We found that the initial life-history composition of coral taxa largely determined the impacts of bleaching and coral loss. Prior to the 1998 bleaching event, coral assemblages within no-take marine reserves were composed of three distinct life histories - competitive, stress-tolerant and weedy- and exhibited strong declines following bleaching with limited subsequent recovery. In contrast, fished reefs had lower coral cover, fewer genera and were composed of stress-tolerant and weedy corals that were less affected by bleaching over the long term. Despite these general patterns, we found limited evidence for cotolerance as coral genera and life histories were variable in their sensitivities to fishing and bleaching. Overall, fishing and bleaching have reduced coral diversity and led to altered coral communities of 'survivor' species with stress-tolerant and weedy life histories. Our findings are consistent with expectations that climate change interacting with existing human pressure will result in the loss of coral diversity and critical reef habitat. © 2013 Blackwell Publishing Ltd.

A dynamic bioenergetic model for coral-Symbiodinium symbioses and coral bleaching as an alternate stable state.

PubMed

Cunning, Ross; Muller, Erik B; Gates, Ruth D; Nisbet, Roger M

2017-10-27

Coral reef ecosystems owe their ecological success - and vulnerability to climate change - to the symbiotic metabolism of corals and Symbiodinium spp. The urgency to understand and predict the stability and breakdown of these symbioses (i.e., coral 'bleaching') demands the development and application of theoretical tools. Here, we develop a dynamic bioenergetic model of coral-Symbiodinium symbioses that demonstrates realistic steady-state patterns in coral growth and symbiont abundance across gradients of light, nutrients, and feeding. Furthermore, by including a mechanistic treatment of photo-oxidative stress, the model displays dynamics of bleaching and recovery that can be explained as transitions between alternate stable states. These dynamics reveal that "healthy" and "bleached" states correspond broadly to nitrogen- and carbon-limitation in the system, with transitions between them occurring as integrated responses to multiple environmental factors. Indeed, a suite of complex emergent behaviors reproduced by the model (e.g., bleaching is exacerbated by nutrients and attenuated by feeding) suggests it captures many important attributes of the system; meanwhile, its modular framework and open source R code are designed to facilitate further problem-specific development. We see significant potential for this modeling framework to generate testable hypotheses and predict integrated, mechanistic responses of corals to environmental change, with important implications for understanding the performance and maintenance of symbiotic systems. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Inhibition of coral recruitment by macroalgae and cyanobacteria

USGS Publications Warehouse

Kuffner, I.B.; Walters, L.J.; Becerro, M.A.; Paul, V.J.; Ritson-Williams, R.; Beach, K.S.

2006-01-01

Coral recruitment is a key process in the maintenance and recovery of coral reef ecosystems. While intense competition between coral and algae is often assumed on reefs that have undergone phase shifts from coral to algal dominance, data examining the competitive interactions involved, particularly during the larval and immediate post-settlement stage, are scarce. Using a series of field and outdoor seawater table experiments, we tested the hypothesis that common species of macroalgae and cyanobacteria inhibit coral recruitment. We examined the effects of Lyngbya spp., Dictyota spp., Lobophora variegata (J. V. Lamouroux) Womersley, and Chondrophycus poiteaui (J. V. Lamouroux) Nam (formerly Laurencia poiteaui) on the recruitment success of Porites astreoides larvae. All species but C. poiteaui caused either recruitment inhibition or avoidance behavior in P. astreoides larvae, while L. confervoides and D. menstrualis significantly increased mortality rates of P. astreoides recruits. We also tested the effect of some of these macrophytes on larvae of the gorgonian octocoral Briareum asbestinum. Exposure to Lyngbya majuscula reduced survival and recruitment in the octocoral larvae. Our results provide evidence that algae and cyanobacteria use tactics beyond space occupation to inhibit coral recruitment. On reefs experiencing phase shifts or temporary algal blooms, the restocking of adult coral populations may be slowed due to recruitment inhibition, thereby perpetuating reduced coral cover and limiting coral community recovery. ?? Inter-Research 2006.

Biodiversity of Spongosorites coralliophaga (Stephens, 1915) on coral rubble at two contrasting cold-water coral reef settings

NASA Astrophysics Data System (ADS)

Kazanidis, Georgios; Henry, Lea-Anne; Roberts, J. Murray; Witte, Ursula F. M.

2016-03-01

Cold-water coral reefs (CWRs) in the northeast Atlantic harbor diverse sponge communities. Knowledge of deep-sea sponge ecology is limited and this leaves us with a fragmented understanding of the ecological roles that sponges play in CWR ecosystems. We present the first study of faunal biodiversity associated with the massive demosponge Spongosorites coralliophaga (Stephens, 1915) that typically colonizes coral debris fields of CWRs. Our study focused on the sessile fauna inhabiting sponges mixed with coral rubble at two contrasting settings in the northeast Atlantic: the shallow inshore (120-190 m water depth) Mingulay Reef Complex (MRC) and the deep offshore (500-1200 m) Logachev Mound (LM) coral province. MRC is dominated by the scleractinian Lophelia pertusa, while LM is dominated by L. pertusa and Madrepora oculata. Nine sponge-coral rubble associations were collected from MRC and four from LM. Measurements of abundance, species richness, diversity, evenness, dry biomass, and composition of sessile fauna on sponge and coral rubble microhabitats were undertaken. Differences in community composition between the two regions were mainly a response to changes in fauna with depth. Fauna composition was also different between sponge and coral rubble within each region. Infauna constituted a minor component of the sponge-associated fauna in MRC but had a higher contribution in LM. Sponge and coral rubble sessile fauna in both regions was mainly composed of cnidarians and molluscs, similarly to some previous studies. Sponges' outer surfaces at MRC were colonized by a species-rich community with high abundance and biomass suggesting that S. coralliophaga at MRC acts as a settlement surface for various organisms but such a role is not the case at LM. This difference in the role of S. coralliophaga as a biological structure is probably related to differences in fauna composition with depth, bottom current speed, and the quantity/quality of food supplied to the benthos.