Poorly cemented coral reefs of the eastern tropical Pacific: possible insights into reef development in a high-CO2 world.

PubMed

Manzello, Derek P; Kleypas, Joan A; Budd, David A; Eakin, C Mark; Glynn, Peter W; Langdon, Chris

2008-07-29

Ocean acidification describes the progressive, global reduction in seawater pH that is currently underway because of the accelerating oceanic uptake of atmospheric CO(2). Acidification is expected to reduce coral reef calcification and increase reef dissolution. Inorganic cementation in reefs describes the precipitation of CaCO(3) that acts to bind framework components and occlude porosity. Little is known about the effects of ocean acidification on reef cementation and whether changes in cementation rates will affect reef resistance to erosion. Coral reefs of the eastern tropical Pacific (ETP) are poorly developed and subject to rapid bioerosion. Upwelling processes mix cool, subthermocline waters with elevated pCO(2) (the partial pressure of CO(2)) and nutrients into the surface layers throughout the ETP. Concerns about ocean acidification have led to the suggestion that this region of naturally low pH waters may serve as a model of coral reef development in a high-CO(2) world. We analyzed seawater chemistry and reef framework samples from multiple reef sites in the ETP and found that a low carbonate saturation state (Omega) and trace abundances of cement are characteristic of these reefs. These low cement abundances may be a factor in the high bioerosion rates previously reported for ETP reefs, although elevated nutrients in upwelled waters may also be limiting cementation and/or stimulating bioerosion. ETP reefs represent a real-world example of coral reef growth in low-Omega waters that provide insights into how the biological-geological interface of coral reef ecosystems will change in a high-CO(2) world.

50 CFR 622.77 - Adjustment of management measures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ATLANTIC Coral and Coral Reefs of the Gulf of Mexico § 622.77 Adjustment of management measures. In accordance with the framework procedures of the FMP for Coral and Coral Reefs of the Gulf of Mexico, the RA may establish or modify the following: (a) Gulf coral resources. For a species or species group...

50 CFR 622.77 - Adjustment of management measures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ATLANTIC Coral and Coral Reefs of the Gulf of Mexico § 622.77 Adjustment of management measures. In accordance with the framework procedures of the FMP for Coral and Coral Reefs of the Gulf of Mexico, the RA may establish or modify the following: (a) Gulf coral resources. For a species or species group...

Using virtual reality to estimate aesthetic values of coral reefs

PubMed Central

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

2018-01-01

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

Using virtual reality to estimate aesthetic values of coral reefs.

PubMed

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

2018-04-01

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

A Strategic Framework for Responding to Coral Bleaching Events in a Changing Climate

NASA Astrophysics Data System (ADS)

Maynard, J. A.; Johnson, J. E.; Marshall, P. A.; Eakin, C. M.; Goby, G.; Schuttenberg, H.; Spillman, C. M.

2009-07-01

The frequency and severity of mass coral bleaching events are predicted to increase as sea temperatures continue to warm under a global regime of rising ocean temperatures. Bleaching events can be disastrous for coral reef ecosystems and, given the number of other stressors to reefs that result from human activities, there is widespread concern about their future. This article provides a strategic framework from the Great Barrier Reef to prepare for and respond to mass bleaching events. The framework presented has two main inter-related components: an early warning system and assessment and monitoring. Both include the need to proactively and consistently communicate information on environmental conditions and the level of bleaching severity to senior decision-makers, stakeholders, and the public. Managers, being the most timely and credible source of information on bleaching events, can facilitate the implementation of strategies that can give reefs the best chance to recover from bleaching and to withstand future disturbances. The proposed framework is readily transferable to other coral reef regions, and can easily be adapted by managers to local financial, technical, and human resources.

Differential impact of monsoon and large amplitude internal waves on coral reef development in the Andaman Sea.

PubMed

Wall, Marlene; Schmidt, Gertraud Maria; Janjang, Pornpan; Khokiattiwong, Somkiat; Richter, Claudio

2012-01-01

The Andaman Sea and other macrotidal semi-enclosed tropical seas feature large amplitude internal waves (LAIW). Although LAIW induce strong fluctuations i.e. of temperature, pH, and nutrients, their influence on reef development is so far unknown. A better-known source of disturbance is the monsoon affecting corals due to turbulent mixing and sedimentation. Because in the Andaman Sea both, LAIW and monsoon, act from the same westerly direction their relative contribution to reef development is difficult to discern. Here, we explore the framework development in a number of offshore island locations subjected to differential LAIW- and SW-monsoon impact to address this open question. Cumulative negative temperature anomalies - a proxy for LAIW impact - explained a higher percentage of the variability in coral reef framework height, than sedimentation rates which resulted mainly from the monsoon. Temperature anomalies and sediment grain size provided the best correlation with framework height suggesting that so far neglected subsurface processes (LAIW) play a significant role in shaping coral reefs.

Mesophotic bioerosion: Variability and structural impact on U.S. Virgin Island deep reefs

NASA Astrophysics Data System (ADS)

Weinstein, David K.; Smith, Tyler B.; Klaus, James S.

2014-10-01

Mesophotic reef corals, found 30-150 m below sea level, build complex structures that provide habitats for diverse ecosystems. Whereas bioerosion is known to impact the development and persistence of shallow reef structures, little is known regarding the extent of mesophotic bioerosion or how it might affect deeper reef geomorphology and carbonate accretion. Originally pristine experimental coral substrates and collected coral rubble were both used to investigate the variation and significance of mesophotic coral reef bioerosion south of St. Thomas, U.S. Virgin Islands. Bioerosion rates were calculated from experimental coral substrates exposed as framework for 1 and 2 years at four structurally distinct mesophotic coral reef habitats (between 30 and 45 m) as well as at a mid-shelf patch reef (21 m) and a shallow fringing patch reef (9 m). The long-term effects of macroboring were assessed by examining coral rubble collected at all sites. Overall, differences in bioerosional processes were found between shallow and mesophotic reefs. Increases in bioerosion on experimental substrates (amount of weight lost) were related to both decreasing seawater depth and increasing biomass of bioeroding parrotfish. Significant differences in coral skeleton bioerosion rates were also found between the transitional mesophotic reef zone (30-35 m) and the upper mesophotic reef zone (35-50 m) after 2 years of exposure, ranging from - 19.6 to 3.7 g/year. Total coral rubble macroboring was greater at most deep sites compared to shallower sites. Bioerosional grazing was found to dominate initial substrate modification in reefs 30.7 m and shallower, but sponges are believed to act as the main time-averaged long-term substrate bioeroders in reefs between 35 and 50 m. Although initial substrate bioerosion rates of a uniform substrate were relatively homogeneous in the 35-50 m depth zone, comparison of site composition suggests that mesophotic bioerosion will vary depending on the amount, location, and type of available substrate, and the duration both coral rubble and in situ coral framework are exposed on the seafloor. These variations may exaggerate pronounced structural differences in mesophotic reef habitats that experience few other methods of erosion.

Upper Miocene reef complex of Mallorca, Balearic Islands, Spain

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

Pomar, L.

1988-02-01

The late Tortonian-Messinian coral reef platform of south Mallorca onlaps a folded middle late Miocene carbonate platform on which progradation of up to 20 km occurs. Vertical sea cliffs (up to 100 m high) superbly show the last 5 km of this progradation and complement the numerous water-well cores from the island interior. The Mallorca reef presents the most complete facies zonation of the Miocene reefs of the western Mediterranean. The reef wall framework is up to 20 m thick and shows (1) erosional reef flat with reef breccia and small corals; (2) spur-and-grove zone with large, massive corals; (3)more » deep buttresses and pinnacles with terraces of branching corals; and (4) deep reef wall with flat, laminar coral colonies, branching red algae, and Halimeda sands.« less

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

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.

First observations of the structure and megafaunal community of a large Lophelia reef on the Ghanaian shelf (the Gulf of Guinea)

NASA Astrophysics Data System (ADS)

Buhl-Mortensen, L.; Serigstad, B.; Buhl-Mortensen, P.; Olsen, M. N.; Ostrowski, M.; Błażewicz-Paszkowycz, M.; Appoh, E.

2017-03-01

The distribution of cold-water coral reefs is relatively well known in the North-east Atlantic as compared to the Central-east Atlantic, where only a few documentations exist from low latitudes. In 2012 an initial survey was conducted on a reef situated at 400 m depth on the continental shelf off Ghana. The reef corals and fauna were visually documented using a Video Assisted Multi Sampler (VAMS) coupled with an ROV. Here we present the results from three dives on the 1400 m long and 70 m high reef with an ambient temperatures between 9 and 10 °C. The banana shaped reef was oriented perpendicular to the main current, the convex side facing the current and there was no sign of human impact. The great height of the reef is probably a result of undisturbed growth for more than 20,000 years. On the Norwegian continental shelf the largest reefs are around 30 m high and have been aged to 9000 years. The reef morphology resembles that of Northeast Atlantic Lophelia reefs. The main reef building coral was Lophelia pertusa with contribution from Madrepora oculata, Solenosmilia variabilis, and occasional occurrences of Dendrophyllia cf. alternata. The skeleton of Aphrocallistes beatrix (Hexactinellidae) contributed to the reef framework and the reef consisted of 46% coral blocks 22% sediment, 13% coral rubble, 11% sponge skeleton and 8% live corals. A rich megafauna of 31 taxa was recorded and most frequent was Acesta excavate (bivalve), Aphrocallistes beatrix (with an associated Zooanthida on 39% of the colonies), squat lobsters, hydroids and bryozoans. Six fish species were recorded of which the Sebastidae Helicolenus dactylopterus and Nettastoma melanurum were found amongst coral blocks. The reef community showed several similarities with the northern reefs with sponges, Sebastes spp., squat lobsters, and Acesta excavata being common megafauna associates. In contrast the gorgonian corals that are characteristic of the northern reefs seemed to be lacking and Hexactinellidae rather than Demospongia were common on the reef and contributed to the reef framework. Crabs that are uncommon on northern reefs were frequently encountered.

Ecological solutions to reef degradation: optimizing coral reef restoration in the Caribbean and Western Atlantic

PubMed Central

2016-01-01

Reef restoration activities have proliferated in response to the need to mitigate coral declines and recover lost reef structure, function, and ecosystem services. Here, we describe the recent shift from costly and complex engineering solutions to recover degraded reef structure to more economical and efficient ecological approaches that focus on recovering the living components of reef communities. We review the adoption and expansion of the coral gardening framework in the Caribbean and Western Atlantic where practitioners now grow and outplant 10,000’s of corals onto degraded reefs each year. We detail the steps for establishing a gardening program as well as long-term goals and direct and indirect benefits of this approach in our region. With a strong scientific basis, coral gardening activities now contribute significantly to reef and species recovery, provide important scientific, education, and outreach opportunities, and offer alternate livelihoods to local stakeholders. While challenges still remain, the transition from engineering to ecological solutions for reef degradation has opened the field of coral reef restoration to a wider audience poised to contribute to reef conservation and recovery in regions where coral losses and recruitment bottlenecks hinder natural recovery. PMID:27781176

Ecological solutions to reef degradation: optimizing coral reef restoration in the Caribbean and Western Atlantic.

PubMed

Lirman, Diego; Schopmeyer, Stephanie

2016-01-01

Reef restoration activities have proliferated in response to the need to mitigate coral declines and recover lost reef structure, function, and ecosystem services. Here, we describe the recent shift from costly and complex engineering solutions to recover degraded reef structure to more economical and efficient ecological approaches that focus on recovering the living components of reef communities. We review the adoption and expansion of the coral gardening framework in the Caribbean and Western Atlantic where practitioners now grow and outplant 10,000's of corals onto degraded reefs each year. We detail the steps for establishing a gardening program as well as long-term goals and direct and indirect benefits of this approach in our region. With a strong scientific basis, coral gardening activities now contribute significantly to reef and species recovery, provide important scientific, education, and outreach opportunities, and offer alternate livelihoods to local stakeholders. While challenges still remain, the transition from engineering to ecological solutions for reef degradation has opened the field of coral reef restoration to a wider audience poised to contribute to reef conservation and recovery in regions where coral losses and recruitment bottlenecks hinder natural recovery.

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

NASA Astrophysics Data System (ADS)

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

2016-06-01

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

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.

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.

History of Indo-Pacific coral reef systems since the last glaciation: Development patterns and controlling factors

NASA Astrophysics Data System (ADS)

Montaggioni, Lucien F.

2005-06-01

A significant body of new information about the development of coral reefs during the last 23 ka has been generated in the last three decades. In the Indo-Pacific province, structures from a variety of geodynamic settings have been investigated using subsurface drilling and submersible diving. This paper is based principally on the re-examination of the core dataset from the literature, with reconversion of many previously published radiocarbon ages into calendar dates. Seven framework and three detrital facies were identified on the basis of the nature and growth shapes of dominant framework builders, and on that of the texture of sediments, respectively. Framework facies in high-hydrodynamic energy settings were dominated by an association of coralline algae and robust-branching corals ( Acropora robusta group, A. gr. humilis, A. palifera, Pocillopora damicornis) with locally encrusting coral forms (faviids). In moderate energy environments, these were replaced by domal ( Porites), tabular-branching ( Acropora gr. hyacinthus) and arborescent ( Acropora gr. muricata), whereas sheltered areas included an association of arborescent, foliaceous ( Montipora, Pavona) and encrusting coral species. Detrital facies comprise coral rubble, carbonate sand and mud. On compositional and textural bases, four main sand subfacies were recognized: coralgal rudstone to packstone; coral-molluscan grainstone/packstone; molluscan-foraminiferal grainstone/packstone; and green algal ( Halimeda) grainstone/packstone. Despite some overlaps in the sand facies association, each subfacies can provide additional support to reconstruction of paleoreef environments. Three types of framework facies association were identified within entire reef-margin sequences: framework of homogeneous composition reflecting stability of environmental conditions through time; superimposition of two distinct frameworks, usually as deeper water corals overlain by shallower, higher energy ones, and recurrent alternations of shallower and deeper coral assemblages. The two last associations resulted probably from lateral displacements of coral communities in response to rapid changes in accommodation space. Such facies transitions also are described from backreef sediment piles: gravel graded into sand and mud successively as a result of upward shallowing. The degree of reef development seems to be linked to coral community structure. Communities consisting principally of branching and domal coral forms favoured substantial accretion and the formation of well-developed reefs, whereas assemblages comprising foliaceous and encrusting colonies produced only incipient reefs. Within reef systems, the proportions of detritus over framework tend to increase as hydrodynamic energy declines. The Indo-Pacific reef systems are classified into four anatomy types on the basis of dominant depositional patterns: balanced aggrading/onlapping, unbalanced aggrading/downlapping, prograding and backstepping types. Vertical accretion rates of frameworks are highly variable and are not directly dictated by coral growth habits. However, the highest rates recorded (up to 20 mm year -1) relate to tabular- and arborescent-acroporid rich sections. Abrupt variations in the aggradation rates of framework are recorded in sequences at the transitional zone between two distinct coral assemblages. In detritus-dominated sequences, accumulation rates range from 0.2 to about 40 mm year -1, with higher values suggesting intense hurricane-controlled deposition. In addition, accretion rates also seem to depend on water-energy conditions. In high-energy environments, aggradation rates did not exceed 12 mm year -1, but reached 25 mm year -1 in more protected areas. By contrast, lateral accretion operated at an average rate of 90 mm year -1 in agitated waters, while it did not exceed the mean rate of 55 mm year -1 in calm waters. Changes in accretion rates appear to be linked to reef growth modes. In the reef zones driven by a "keep-up" mode, mean vertical accretion rates range at around 6 mm year -1. The reef zones developed through a "catch-up" mode at rates of 3-4 mm year -1. There was little variation in accretion rates according to latitude. At the Last Glacial Maximum, from 23 to about 19 ka BP, reefs (Reef Generation RGO) only developed along what were to become the foreslopes of present reefs, forming accumulations a few metres thick at vertical rates of up to 1 mm year -1. The rapid postglacial rise in sea level, from about 19 to 6.5 ka BP, was accompanied by the settlement of three successive reef generations (the so called RGI, RGII and RGIII), within the periods 17.5-14.7, 13.8-11.5 and 10 ka BP to the Present. During the Postglacial transgression, regional to local differences in gross morphology and internal architecture of the reefs have been determined by differing sea-level histories in combination with neotectonics and typographic factors. Locally, reef colonization seems to have been facilitated or prevented chiefly by small-scale topographic features. Development during subsequent deglaciation was probably largely independent of variations in sea surface temperatures. Water turbidity also seems to have been only a minor determinant of reef settlement and growth, but may locally have controlled the composition of coral communities, resulting in the growth of turbidity-tolerant domal and foliaceous forms. Changes in atmospheric CO 2 levels remained within the tolerance thresholds for reef calcification. The three main reef growth episodes coincide roughly with rapid increases in atmospheric pCO 2. Dust input and variations in sea surface salinities seem to have had a very limited control on reef growth. The LGM was characterized by salinities comparable with those of the present, but by higher dust fluxes. By contrast, nutrient levels, hydrodynamic energy, and to a lesser, extent coral recruitment in relation to substrate availability and ocean circulation, have played major roles in determining reef accretion patterns at both local and regional scales. Two periods of increased upwelling in the western Indian Ocean, at 15.3 and 11.5-10.8 ka BP, coincided with the demise of RGI and RGII. During deglaciation, high-frequency storm events probably led to a scarcity of typical growth framework reefs and favoured the formation of structures composed of reworked and recemented coral framework. Storm control may have been particularly important in the mid-Holocene when water depths over incipient reefs were greater than 5 m. From the LGM to the early Holocene, coral settlement has probably declined due to a lack of suitable nurseries, until the modern patterns of ocean circulation were established and thus favoured larval dispersal from refuges. It is highly desirable to improve analysis of the core database and to increase the number of core-transects, including forereef sites, to enhance our knowledge of Recent reef development.

Macrobioerosion in Porites corals in subtropical northern South China Sea: a limiting factor for high-latitude reef framework development

NASA Astrophysics Data System (ADS)

Chen, Tianran; Li, Shu; Yu, Kefu

2013-03-01

Bioerosion is an important limiting factor in carbonate accretion and reef framework development; however, few studies have quantified the direct impact of macroborers on high-latitude coral communities, which are viewed as potential refuge during a period of global warming. In this study, internal macrobioerosion of Porites corals was examined at Daya Bay, subtropical northern South China Sea. The principal borers were the bivalve Lithophaga spp. and the sponges Cliona spp. and Cliothosa spp. (≥80 %), while sipunculid and polychaete worms and barnacles accounted for small amounts of bioerosion (≤20 %). Porites corals were heavily bioeroded in areas impacted by aquacultural and urban activities (10.34-27.55 %) compared with corals in relatively unpolluted areas (2.18-6.76 %). High levels of bioerosion, especially boring bivalve infestation, significantly weaken the corals and increase their susceptibility to dislodgement and fragmentation in typhoons, limiting accumulation of limestone framework. This study implies that carbonate accretion and reef development for high-latitude coral communities may be limited in future high-CO2 and eutrophication-stressed environments.

Resilience and climate change: lessons from coral reefs and bleaching in the Western Indian Ocean

NASA Astrophysics Data System (ADS)

Obura, David O.

2005-05-01

The impact of climate change through thermal stress-related coral bleaching on coral reefs of the Western Indian Ocean has been well documented and is caused by rising sea water temperatures associated with background warming trends and extreme climate events. Recent studies have identified a number of factors that may reduce the impact of coral bleaching and mortality at a reef or sub-reef level. However, there is little scientific consensus as yet, and it is unclear how well current science supports the immediate needs of management responses to climate change. This paper provides evidence from the Western Indian Ocean in support of recent hypotheses on coral and reef vulnerability to thermal stress that have been loosely termed 'resistance and resilience to bleaching'. The paper argues for a more explicit definition of terms, and identifies three concepts affecting coral-zooxanthellae holobiont and reef vulnerability to thermal stress previously termed 'resistance to bleaching': 'thermal protection', where some reefs are protected from the thermal conditions that induce bleaching and/or where local physical conditions reduce bleaching and mortality levels; 'thermal resistance', where individual corals bleach to differing degrees to the same thermal stress; and 'thermal tolerance', where individual corals suffer differing levels of mortality when exposed to the same thermal stress. 'Resilience to bleaching' is a special case of ecological resilience, where recovery following large-scale bleaching mortality varies according to ecological and other processes. These concepts apply across multiple levels of biological organization and temporal and spatial scales. Thermal resistance and tolerance are genetic properties and may interact with environmental protection properties resulting in phenotypic variation in bleaching and mortality of corals. The presence or absence of human threats and varying levels of reef management may alter the influence of the above factors, particularly through their impacts on resilience, offering the opportunity for management interventions to mitigate the impacts of thermal stress and recovery on coral reefs. These concepts are compiled within an overarching framework of spatial resilience theory. This provides a framework for developing linked scientific and management questions relating to the larger scale impacts of climate change on coral reefs, their management needs and prospects for their future.

Drivers and predictions of coral reef carbonate budget trajectories

PubMed Central

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

2017-01-01

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

Drivers and predictions of coral reef carbonate budget trajectories.

PubMed

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

2017-01-25

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

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

NASA Astrophysics Data System (ADS)

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

2017-03-01

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

50 CFR 665.18 - Framework adjustments to management measures.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... By July 31 of each year, a Council-appointed coral reef ecosystem monitoring team will prepare an annual report on coral reef fisheries of the western Pacific region. The report will contain, among other... may establish a new target number based on the 5-year review. (d) Precious coral measures—(1...

Effects of ocean acidification on the dissolution rates of reef-coral skeletons.

PubMed

van Woesik, Robert; van Woesik, Kelly; van Woesik, Liana; van Woesik, Sandra

2013-01-01

Ocean acidification threatens the foundation of tropical coral reefs. This study investigated three aspects of ocean acidification: (i) the rates at which perforate and imperforate coral-colony skeletons passively dissolve when pH is 7.8, which is predicted to occur globally by 2100, (ii) the rates of passive dissolution of corals with respect to coral-colony surface areas, and (iii) the comparative rates of a vertical reef-growth model, incorporating passive dissolution rates, and predicted sea-level rise. By 2100, when the ocean pH is expected to be 7.8, perforate Montipora coral skeletons will lose on average 15 kg CaCO3 m(-2) y(-1), which is approximately -10.5 mm of vertical reduction of reef framework per year. This rate of passive dissolution is higher than the average rate of reef growth over the last several millennia and suggests that reefs composed of perforate Montipora coral skeletons will have trouble keeping up with sea-level rise under ocean acidification. Reefs composed of primarily imperforate coral skeletons will not likely dissolve as rapidly, but our model shows they will also have trouble keeping up with sea-level rise by 2050.

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

PubMed

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

2016-11-01

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

No Reef Is an Island: Integrating Coral Reef Connectivity Data into the Design of Regional-Scale Marine Protected Area Networks.

PubMed

Schill, Steven R; Raber, George T; Roberts, Jason J; Treml, Eric A; Brenner, Jorge; Halpin, Patrick N

2015-01-01

We integrated coral reef connectivity data for the Caribbean and Gulf of Mexico into a conservation decision-making framework for designing a regional scale marine protected area (MPA) network that provides insight into ecological and political contexts. We used an ocean circulation model and regional coral reef data to simulate eight spawning events from 2008-2011, applying a maximum 30-day pelagic larval duration and 20% mortality rate. Coral larval dispersal patterns were analyzed between coral reefs across jurisdictional marine zones to identify spatial relationships between larval sources and destinations within countries and territories across the region. We applied our results in Marxan, a conservation planning software tool, to identify a regional coral reef MPA network design that meets conservation goals, minimizes underlying threats, and maintains coral reef connectivity. Our results suggest that approximately 77% of coral reefs identified as having a high regional connectivity value are not included in the existing MPA network. This research is unique because we quantify and report coral larval connectivity data by marine ecoregions and Exclusive Economic Zones (EZZ) and use this information to identify gaps in the current Caribbean-wide MPA network by integrating asymmetric connectivity information in Marxan to design a regional MPA network that includes important reef network connections. The identification of important reef connectivity metrics guides the selection of priority conservation areas and supports resilience at the whole system level into the future.

No Reef Is an Island: Integrating Coral Reef Connectivity Data into the Design of Regional-Scale Marine Protected Area Networks

PubMed Central

Schill, Steven R.; Raber, George T.; Roberts, Jason J.; Treml, Eric A.; Brenner, Jorge; Halpin, Patrick N.

2015-01-01

We integrated coral reef connectivity data for the Caribbean and Gulf of Mexico into a conservation decision-making framework for designing a regional scale marine protected area (MPA) network that provides insight into ecological and political contexts. We used an ocean circulation model and regional coral reef data to simulate eight spawning events from 2008–2011, applying a maximum 30-day pelagic larval duration and 20% mortality rate. Coral larval dispersal patterns were analyzed between coral reefs across jurisdictional marine zones to identify spatial relationships between larval sources and destinations within countries and territories across the region. We applied our results in Marxan, a conservation planning software tool, to identify a regional coral reef MPA network design that meets conservation goals, minimizes underlying threats, and maintains coral reef connectivity. Our results suggest that approximately 77% of coral reefs identified as having a high regional connectivity value are not included in the existing MPA network. This research is unique because we quantify and report coral larval connectivity data by marine ecoregions and Exclusive Economic Zones (EZZ) and use this information to identify gaps in the current Caribbean-wide MPA network by integrating asymmetric connectivity information in Marxan to design a regional MPA network that includes important reef network connections. The identification of important reef connectivity metrics guides the selection of priority conservation areas and supports resilience at the whole system level into the future. PMID:26641083

Water quality and coral bleaching thresholds: formalising the linkage for the inshore reefs of the Great Barrier Reef, Australia.

PubMed

Wooldridge, Scott A

2009-05-01

The threats of wide-scale coral bleaching and reef demise associated with anthropogenic climate change are widely known. Here, the additional role of poor water quality in lowering the thermal tolerance (i.e. bleaching 'resistance') of symbiotic reef corals is considered. In particular, a quantitative linkage is established between terrestrially-sourced dissolved inorganic nitrogen (DIN) loading and the upper thermal bleaching thresholds of inshore reefs on the Great Barrier Reef, Australia. Significantly, this biophysical linkage provides concrete evidence for the oft-expressed belief that improved coral reef management will increase the regional-scale survival prospects of corals reefs to global climate change. Indeed, for inshore reef areas with a high runoff exposure risk, it is shown that the potential benefit of this 'local' management imperative is equivalent to approximately 2.0-2.5 degrees C in relation to the upper thermal bleaching limit; though in this case, a potentially cost-prohibitive reduction in end-of-river DIN of >50-80% would be required. An integrated socio-economic modelling framework is outlined that will assist future efforts to understand (optimise) the alternate tradeoffs that the water quality/coral bleaching linkage presents.

A framework for responding to coral disease outbreaks that facilitates adaptive management.

PubMed

Beeden, Roger; Maynard, Jeffrey A; Marshall, Paul A; Heron, Scott F; Willis, Bette L

2012-01-01

Predicted increases in coral disease outbreaks associated with climate change have implications for coral reef ecosystems and the people and industries that depend on them. It is critical that coral reef managers understand these implications and have the ability to assess and reduce risk, detect and contain outbreaks, and monitor and minimise impacts. Here, we present a coral disease response framework that has four core components: (1) an early warning system, (2) a tiered impact assessment program, (3) scaled management actions and (4) a communication plan. The early warning system combines predictive tools that monitor the risk of outbreaks of temperature-dependent coral diseases with in situ observations provided by a network of observers who regularly report on coral health and reef state. Verified reports of an increase in disease prevalence trigger a tiered response of more detailed impact assessment, targeted research and/or management actions. The response is scaled to the risk posed by the outbreak, which is a function of the severity and spatial extent of the impacts. We review potential management actions to mitigate coral disease impacts and facilitate recovery, considering emerging strategies unique to coral disease and more established strategies to support reef resilience. We also describe approaches to communicating about coral disease outbreaks that will address common misperceptions and raise awareness of the coral disease threat. By adopting this framework, managers and researchers can establish a community of practice and can develop response plans for the management of coral disease outbreaks based on local needs. The collaborations between managers and researchers we suggest will enable adaptive management of disease impacts following evaluating the cost-effectiveness of emerging response actions and incrementally improving our understanding of outbreak causation.

A Framework for Responding to Coral Disease Outbreaks that Facilitates Adaptive Management

NASA Astrophysics Data System (ADS)

Beeden, Roger; Maynard, Jeffrey A.; Marshall, Paul A.; Heron, Scott F.; Willis, Bette L.

2012-01-01

Predicted increases in coral disease outbreaks associated with climate change have implications for coral reef ecosystems and the people and industries that depend on them. It is critical that coral reef managers understand these implications and have the ability to assess and reduce risk, detect and contain outbreaks, and monitor and minimise impacts. Here, we present a coral disease response framework that has four core components: (1) an early warning system, (2) a tiered impact assessment program, (3) scaled management actions and (4) a communication plan. The early warning system combines predictive tools that monitor the risk of outbreaks of temperature-dependent coral diseases with in situ observations provided by a network of observers who regularly report on coral health and reef state. Verified reports of an increase in disease prevalence trigger a tiered response of more detailed impact assessment, targeted research and/or management actions. The response is scaled to the risk posed by the outbreak, which is a function of the severity and spatial extent of the impacts. We review potential management actions to mitigate coral disease impacts and facilitate recovery, considering emerging strategies unique to coral disease and more established strategies to support reef resilience. We also describe approaches to communicating about coral disease outbreaks that will address common misperceptions and raise awareness of the coral disease threat. By adopting this framework, managers and researchers can establish a community of practice and can develop response plans for the management of coral disease outbreaks based on local needs. The collaborations between managers and researchers we suggest will enable adaptive management of disease impacts following evaluating the cost-effectiveness of emerging response actions and incrementally improving our understanding of outbreak causation.

Onondage pinnacle reefs in New York State

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

Friedman, G.M.

1995-09-01

Onondaga pinnacle reefs, part of the Onondaga Formation, developed in an epeiric setting of the lowermost Middle Devonian (Eifelian). The reefs were initiated as coral-crinoidal mounds in the Edgecliff Member of the formation. Whereas most Devonian reefs are composed of rugose corals. Coral is the predominant kind of fossil, followed by crinoids, brachiopods, mollusks, undifferentiated skeletal debris, and possible sponges. The initial mineralogy of the corals is inferred to have been calcite. The porosity of these reefs is almost unique among reef reservoirs. most reefs produce from secondary or diagenetic porosity; by contrast Onondaga reefs display primary intracoralline or frameworkmore » porosity. Between framework builders and/or skeletal particles cryptocrystalline/microcrystalline cement fills pores. As observed in modern reefs this kind of cement resembles micrite, but probable formed as high-magnesian calcite in a high-energy setting. Syntaxial or rim cement common lines crinoid particles. Some of these pinnacle reefs, formerly gas producers, are presently under development as gas-storage reservoirs.« less

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.

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

NASA Astrophysics Data System (ADS)

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

2008-12-01

Since the early 1980s, episodes of coral reef bleaching and mortality, due primarily to climate-induced ocean warming, have occurred almost annually in one or more of the world's tropical or subtropical seas. Bleaching is episodic, with the most severe events typically accompanying coupled ocean-atmosphere phenomena, such as the El Niño-Southern Oscillation (ENSO), which result in sustained regional elevations of ocean temperature. Using this extended dataset (25+ years), we review the short- and long-term ecological impacts of coral bleaching on reef ecosystems, and quantitatively synthesize recovery data worldwide. Bleaching episodes have resulted in catastrophic loss of coral cover in some locations, and have changed coral community structure in many others, with a potentially critical influence on the maintenance of biodiversity in the marine tropics. Bleaching has also set the stage for other declines in reef health, such as increases in coral diseases, the breakdown of reef framework by bioeroders, and the loss of critical habitat for associated reef fishes and other biota. Secondary ecological effects, such as the concentration of predators on remnant surviving coral populations, have also accelerated the pace of decline in some areas. Although bleaching severity and recovery have been variable across all spatial scales, some reefs have experienced relatively rapid recovery from severe bleaching impacts. There has been a significant overall recovery of coral cover in the Indian Ocean, where many reefs were devastated by a single large bleaching event in 1998. In contrast, coral cover on western Atlantic reefs has generally continued to decline in response to multiple smaller bleaching events and a diverse set of chronic secondary stressors. No clear trends are apparent in the eastern Pacific, the central-southern-western Pacific or the Arabian Gulf, where some reefs are recovering and others are not. The majority of survivors and new recruits on regenerating and recovering coral reefs have originated from broadcast spawning taxa with a potential for asexual growth, relatively long distance dispersal, successful settlement, rapid growth and a capacity for framework construction. Whether or not affected reefs can continue to function as before will depend on: (1) how much coral cover is lost, and which species are locally extirpated; (2) the ability of remnant and recovering coral communities to adapt or acclimatize to higher temperatures and other climatic factors such as reductions in aragonite saturation state; (3) the changing balance between reef accumulation and bioerosion; and (4) our ability to maintain ecosystem resilience by restoring healthy levels of herbivory, macroalgal cover, and coral recruitment. Bleaching disturbances are likely to become a chronic stress in many reef areas in the coming decades, and coral communities, if they cannot recover quickly enough, are likely to be reduced to their most hardy or adaptable constituents. Some degraded reefs may already be approaching this ecological asymptote, although to date there have not been any global extinctions of individual coral species as a result of bleaching events. Since human populations inhabiting tropical coastal areas derive great value from coral reefs, the degradation of these ecosystems as a result of coral bleaching and its associated impacts is of considerable societal, as well as biological concern. Coral reef conservation strategies now recognize climate change as a principal threat, and are engaged in efforts to allocate conservation activity according to geographic-, taxonomic-, and habitat-specific priorities to maximize coral reef survival. Efforts to forecast and monitor bleaching, involving both remote sensed observations and coupled ocean-atmosphere climate models, are also underway. In addition to these efforts, attempts to minimize and mitigate bleaching impacts on reefs are immediately required. If significant reductions in greenhouse gas emissions can be achieved within the next two to three decades, maximizing coral survivorship during this time may be critical to ensuring healthy reefs can recover in the long term.

Water Quality Standards for Coral Reef Protection

EPA Science Inventory

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

Enhanced macroboring and depressed calcification drive net dissolution at high-CO2 coral reefs.

PubMed

Enochs, Ian C; Manzello, Derek P; Kolodziej, Graham; Noonan, Sam H C; Valentino, Lauren; Fabricius, Katharina E

2016-11-16

Ocean acidification (OA) impacts the physiology of diverse marine taxa; among them corals that create complex reef framework structures. Biological processes operating on coral reef frameworks remain largely unknown from naturally high-carbon-dioxide (CO 2 ) ecosystems. For the first time, we independently quantified the response of multiple functional groups instrumental in the construction and erosion of these frameworks (accretion, macroboring, microboring, and grazing) along natural OA gradients. We deployed blocks of dead coral skeleton for roughly 2 years at two reefs in Papua New Guinea, each experiencing volcanically enriched CO 2 , and employed high-resolution micro-computed tomography (micro-CT) to create three-dimensional models of changing skeletal structure. OA conditions were correlated with decreased calcification and increased macroboring, primarily by annelids, representing a group of bioeroders not previously known to respond to OA. Incubation of these blocks, using the alkalinity anomaly methodology, revealed a switch from net calcification to net dissolution at a pH of roughly 7.8, within Intergovernmental Panel on Climate Change's (IPCC) predictions for global ocean waters by the end of the century. Together these data represent the first comprehensive experimental study of bioerosion and calcification from a naturally high-CO 2 reef ecosystem, where the processes of accelerated erosion and depressed calcification have combined to alter the permanence of this essential framework habitat. © 2016 The Authors.

Enhanced macroboring and depressed calcification drive net dissolution at high-CO2 coral reefs

PubMed Central

Manzello, Derek P.; Kolodziej, Graham; Noonan, Sam H. C.; Valentino, Lauren; Fabricius, Katharina E.

2016-01-01

Ocean acidification (OA) impacts the physiology of diverse marine taxa; among them corals that create complex reef framework structures. Biological processes operating on coral reef frameworks remain largely unknown from naturally high-carbon-dioxide (CO2) ecosystems. For the first time, we independently quantified the response of multiple functional groups instrumental in the construction and erosion of these frameworks (accretion, macroboring, microboring, and grazing) along natural OA gradients. We deployed blocks of dead coral skeleton for roughly 2 years at two reefs in Papua New Guinea, each experiencing volcanically enriched CO2, and employed high-resolution micro-computed tomography (micro-CT) to create three-dimensional models of changing skeletal structure. OA conditions were correlated with decreased calcification and increased macroboring, primarily by annelids, representing a group of bioeroders not previously known to respond to OA. Incubation of these blocks, using the alkalinity anomaly methodology, revealed a switch from net calcification to net dissolution at a pH of roughly 7.8, within Intergovernmental Panel on Climate Change's (IPCC) predictions for global ocean waters by the end of the century. Together these data represent the first comprehensive experimental study of bioerosion and calcification from a naturally high-CO2 reef ecosystem, where the processes of accelerated erosion and depressed calcification have combined to alter the permanence of this essential framework habitat. PMID:27852802

Morphological plasticity of the depth generalist coral, Montastraea cavernosa, on mesophotic reefs in Bermuda.

PubMed

Goodbody-Gringley, Gretchen; Waletich, Justin

2018-04-02

Scleractinian corals have global ecological, structural, social, and economic importance that is disproportionately large relative to their areal extent. These reef building corals form the architectural framework for shallow water tropical reef systems, supporting the most productive and biologically diverse marine ecosystems on Earth (Veron, 1995). Reef-building scleractinian species are dependent on photosynthetic products supplied by symbiotic zooxanthellae of the genus Symbiodinium, restricting their distribution to the photic zone (Stambler, 2011). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

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.

Fluorescent protein-mediated colour polymorphism in reef corals: multicopy genes extend the adaptation/acclimatization potential to variable light environments.

PubMed

Gittins, John R; D'Angelo, Cecilia; Oswald, Franz; Edwards, Richard J; Wiedenmann, Jörg

2015-01-01

The genomic framework that enables corals to adjust to unfavourable conditions is crucial for coral reef survival in a rapidly changing climate. We have explored the striking intraspecific variability in the expression of coral pigments from the green fluorescent protein (GFP) family to elucidate the genomic basis for the plasticity of stress responses among reef corals. We show that multicopy genes can greatly increase the dynamic range over which corals can modulate transcript levels in response to the light environment. Using the red fluorescent protein amilFP597 in the coral Acropora millepora as a model, we demonstrate that its expression increases with light intensity, but both the minimal and maximal gene transcript levels vary markedly among colour morphs. The pigment concentration in the tissue of different morphs is strongly correlated with the number of gene copies with a particular promoter type. These findings indicate that colour polymorphism in reef corals can be caused by the environmentally regulated expression of multicopy genes. High-level expression of amilFP597 is correlated with reduced photodamage of zooxanthellae under acute light stress, supporting a photoprotective function of this pigment. The cluster of light-regulated pigment genes can enable corals to invest either in expensive high-level pigmentation, offering benefits under light stress, or to rely on low tissue pigment concentrations and use the conserved resources for other purposes, which is preferable in less light-exposed environments. The genomic framework described here allows corals to pursue different strategies to succeed in habitats with highly variable light stress levels. In summary, our results suggest that the intraspecific plasticity of reef corals' stress responses is larger than previously thought. © 2014 The Authors Molecular Ecology Published by John Wiley & Sons Ltd.

Advancing the integration of spatial data to map human and natural drivers on coral reefs

PubMed Central

Gove, Jamison M.; Walecka, Hilary R.; Donovan, Mary K.; Williams, Gareth J.; Jouffray, Jean-Baptiste; Crowder, Larry B.; Erickson, Ashley; Falinski, Kim; Friedlander, Alan M.; Kappel, Carrie V.; Kittinger, John N.; McCoy, Kaylyn; Norström, Albert; Nyström, Magnus; Oleson, Kirsten L. L.; Stamoulis, Kostantinos A.; White, Crow; Selkoe, Kimberly A.

2018-01-01

A major challenge for coral reef conservation and management is understanding how a wide range of interacting human and natural drivers cumulatively impact and shape these ecosystems. Despite the importance of understanding these interactions, a methodological framework to synthesize spatially explicit data of such drivers is lacking. To fill this gap, we established a transferable data synthesis methodology to integrate spatial data on environmental and anthropogenic drivers of coral reefs, and applied this methodology to a case study location–the Main Hawaiian Islands (MHI). Environmental drivers were derived from time series (2002–2013) of climatological ranges and anomalies of remotely sensed sea surface temperature, chlorophyll-a, irradiance, and wave power. Anthropogenic drivers were characterized using empirically derived and modeled datasets of spatial fisheries catch, sedimentation, nutrient input, new development, habitat modification, and invasive species. Within our case study system, resulting driver maps showed high spatial heterogeneity across the MHI, with anthropogenic drivers generally greatest and most widespread on O‘ahu, where 70% of the state’s population resides, while sedimentation and nutrients were dominant in less populated islands. Together, the spatial integration of environmental and anthropogenic driver data described here provides a first-ever synthetic approach to visualize how the drivers of coral reef state vary in space and demonstrates a methodological framework for implementation of this approach in other regions of the world. By quantifying and synthesizing spatial drivers of change on coral reefs, we provide an avenue for further research to understand how drivers determine reef diversity and resilience, which can ultimately inform policies to protect coral reefs. PMID:29494613

Integrating physiological and biomechanical drivers of population growth over environmental gradients on coral reefs.

PubMed

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

2012-03-15

Coral reefs exhibit marked spatial and temporal variability, and coral reef organisms exhibit trade-offs in functional traits that influence demographic performance under different combinations of abiotic environmental conditions. In many systems, trait trade-offs are modelled using an energy and/or nutrient allocation framework. However, on coral reefs, differences in biomechanical vulnerability have major demographic implications, and indeed are believed to play an essential role in mediating species coexistence because highly competitive growth forms are vulnerable to physical dislodgment events that occur with high frequency (e.g. annual summer storms). Therefore, an integrated energy allocation and biomechanics framework is required to understand the effect of physical environmental gradients on species' demographic performance. However, on coral reefs, as in most ecosystems, the effects of environmental conditions on organisms are measured in different currencies (e.g. lipid accumulation, survival and number of gametes), and thus the relative contributions of these effects to overall capacity for population growth are not readily apparent. A comprehensive assessment of links between the environment and the organism, including those mediated by biomechanical processes, must convert environmental effects on individual-level performance (e.g. survival, growth and reproduction) into a common currency that is relevant to the capacity to contribute to population growth. We outline such an approach by considering the population-level performance of scleractinian reef corals over a hydrodynamic gradient, with a focus on the integrating the biomechanical determinants of size-dependent coral colony dislodgment as a function of flow, with the effects of flow on photosynthetic energy acquisition and respiration.

Taphonomy of coral reefs from Southern Lagoon of Belize

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

Westphall, M.J.; Ginsburg, R.N.

1985-02-01

The Southern Lagoon of the Belize barrier complex, an area of some 600 km/sup 2/, contains a tremendous number of lagoon reefs, which range in size from patches several meters across to rhomboidal-shaped structures several kilometers in their long dimension. These lagoon reefs are remarkable because they have Holocene sediment accumulations in excess of 13 m consisting almost entirely of coral debris and lime mud and sand, and rise up to 30 m above the surrounding lagoon floor with steeply sloping sides (50-80/sup 0/), yet are totally uncemented. The reef-building biota and their corresponding deposits were studied at a representativemore » reef, the rhomboidal complex of Channel Cay. As with many of the reefs in this area, the steeply sloping flanks of Channel Cay are covered mainly by the branched staghorn coral Acropora cervicornis and ribbonlike and platy growth of Agaricia spp. The living corals are not cemented to the substrate, but are merely intergrown. Fragmented pieces of corals accumulate with an open framework below the living community; this open framework is subsequently infilled by lime muds and sands produced mainly from bioerosion. Results from probing and coring suggest that the bafflestone fabric of coral debris and sediment extends at least 13 m into the subsurface. Radiocarbon-age estimates indicate these impressive piles of coral rubble and sediment have accumulated in the past 9000 yr (giving a minimum accumulation rate of 1.4 m/1000 yr) and illustrate the potential for significant carbonate buildups without the need for early lithification.« less

Ocean acidification affects coral growth by reducing skeletal density.

PubMed

Mollica, Nathaniel R; Guo, Weifu; Cohen, Anne L; Huang, Kuo-Fang; Foster, Gavin L; Donald, Hannah K; Solow, Andrew R

2018-02-20

Ocean acidification (OA) is considered an important threat to coral reef ecosystems, because it reduces the availability of carbonate ions that reef-building corals need to produce their skeletons. However, while theory predicts that coral calcification rates decline as carbonate ion concentrations decrease, this prediction is not consistently borne out in laboratory manipulation experiments or in studies of corals inhabiting naturally low-pH reefs today. The skeletal growth of corals consists of two distinct processes: extension (upward growth) and densification (lateral thickening). Here, we show that skeletal density is directly sensitive to changes in seawater carbonate ion concentration and thus, to OA, whereas extension is not. We present a numerical model of Porites skeletal growth that links skeletal density with the external seawater environment via its influence on the chemistry of coral calcifying fluid. We validate the model using existing coral skeletal datasets from six Porites species collected across five reef sites and use this framework to project the impact of 21st century OA on Porites skeletal density across the global tropics. Our model predicts that OA alone will drive up to 20.3 ± 5.4% decline in the skeletal density of reef-building Porites corals.

Coral Reef Response to Marine Isotope Stage (MIS) 5e Sea Level Changes in the Granitic Seychelles

NASA Astrophysics Data System (ADS)

Vyverberg, K.; Dechnik, B.; Dutton, A.; Webster, J.; Zwartz, D.

2015-12-01

Sea-level position has a direct control on coral reef morphology and composition. Examining changes in these parameters in fossil reefs can inform reconstructions of past sea-level behavior and, indirectly, ice sheet dynamics. Here we provide a detailed examination of fossil reefs from Marine Isotope Stage (MIS) 5e. These fossil reefs are located in the granitic Seychelles, which is tectonically stable site and far-field from the former margins of Northern Hemisphere ice sheets. To reconstruct relative sea level (RSL), we combine RTK and Total Station elevation surveys with sedimentary and taxonomic evaluations of eight fossil reef sites. Carbonate coralgal reef buildups of the shallowest portion of the reef are preserved in limestone outcrops that are protected by granite boulder overhangs. Two primary outcrop morphologies were observed at these sites: plastering and massive. Plastering outcrops manifest as thin (~ 1 m height x 1 m width x 0.5 m depth) vertical successions of reef framework and detritus, while massive outcrops are larger (~ 2-6 m height x 2-6 m width x 1-2 m depth). The base of these limestone outcrops consistently record a period of reef growth, characterized by corals or coralline algae colonizing the surface or face of a granite boulder and building upwards. This lower reefal unit is capped by a disconformity that is commonly overlain by coral rubble or a ~10 cm thick layer of micrite. Rubble units contain coarse fragments of the coralgal reef buildups while micrite layers consist of a relatively homogeneous fine-grained carbonate, bearing coral-dwelling, Pyrgomatid barnacles. In many of the outcrops, this succession is repeated upsection with another unit of coralgal reef framework capped by a disconformity that is recognized by the sharp transition to coral rubble or micrite with barnacles. We identified four distinct fossil coralgal assemblages in the limestone outcrops. These assemblages are consistent with modern assemblages which constrain the paleo-water depth histories at each site. The combination of reef taxonomy as well as accretion hiatuses provides robust control on the reef, and thus sea-level, history of this region, and by extension, global mean sea level, during MIS 5e.

An overview of Miocene reefs

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

Jordan, C.F. Jr.; Colgan, M.W.; Frost, S.H.

1990-05-01

Miocene reefs lived approximately within the latitudes of 27{degree}S to 48{degree}N compared with 25{degree}S and 32{degree}N for Holocene reefs. This expansion of reef-growing environments was the result of warm Miocene climates, aided by a eustatic sea level rise and tectonic styles that provided numerous foundations for reef development. The majority of Miocene reefs are found in three main areas: (1) Southeast Asia and the western Pacific, (2) the Mediterranean-Middle East, and (3) Middle America and the Caribbean. These regions, with their distinctive suites of coral and foramineral species, formed three biological provinces; respectively, they are the Indo-Pacific, Tethyan, and Westernmore » Atlantic provinces. Miocene reefs in Southeast Asia occur in several foreland basins as patch reef complexes on paleohighs and as barrier reefs in back-arc basins. Those reefs in the Mediterranean occur as fringing reefs, middle-shelf patch reefs, or as barrier reefs on the edges of tectonic blocks associated with Alpine thrust belts. Most reefs in the Caribbean grew on isolated open-ocean highs of volcanic origin. Miocene reefs display a diversity of framework types: (1) coral-encrusting, red algal boundstones with diverse coral faunas, (2) branching coral-encrusting, red algal boundstones with a limited Poritid fauna, (3) encrusting red algal boundstones. Barrier reef systems are especially rich in encrusting red algae and robust corals; grainstones are common as interbedded sediment. Patch reef complexes, however, display muddy carbonate textures, may have less diverse coral faunas, and commonly have larger foraminifera. The global distribution of Miocene reefs is important because (1) it provides insight into a paleoclimatic view of the earth during a major greenhouse stage and (2) Miocene buildups, such as the Arun (EUR of 14 tcf) and Bima fields (EUR of about 100 MMBO), are exploration targets.« less

Defining the biological integrity of coral reefs using a biological condition gradient framework

EPA Science Inventory

Under authority of the Clean Water Act (CWA), the US EPA is committed to protecting the biological integrity of tropical ecosystems, including mangroves, seagrasses and coral reefs that lie within the 3-mile limit of the territorial seas. The biological condition gradient (BCG) w...

A Decision Framework to Protect Coral Reefs in Guánica Bay, Puerto Rico

EPA Science Inventory

A Watershed Management Plan (WMP) for Guánica Bay, Puerto Rico, was introduced in 2008 by a nonprofit organization, the Center for Watershed Protection, with the intent of protecting coral reefs from damage related to watershed discharges. The plan was initially generated with th...

Balance of constructive and destructive carbonate processes on mesophotic coral reefs

NASA Astrophysics Data System (ADS)

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

2013-12-01

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

Symbiotic Dinoflagellate Functional Diversity Mediates Coral Survival under Ecological Crisis.

PubMed

Suggett, David J; Warner, Mark E; Leggat, William

2017-10-01

Coral reefs have entered an era of 'ecological crisis' as climate change drives catastrophic reef loss worldwide. Coral growth and stress susceptibility are regulated by their endosymbiotic dinoflagellates (genus Symbiodinium). The phylogenetic diversity of Symbiodinium frequently corresponds to patterns of coral health and survival, but knowledge of functional diversity is ultimately necessary to reconcile broader ecological success over space and time. We explore here functional traits underpinning the complex biology of Symbiodinium that spans free-living algae to coral endosymbionts. In doing so we propose a mechanistic framework integrating the primary traits of resource acquisition and utilisation as a means to explain Symbiodinium functional diversity and to resolve the role of Symbiodinium in driving the stability of coral reefs under an uncertain future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Miocene reef corals: A review

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

Frost, S.H.

1988-01-01

Tectonic blockage in the Middle East of westward-flowing Tethys surface circulation during the latest Oligocene led to creation in the earliest Miocene of endemic Mediterranean, Western Atlantic-Caribbean, and Indo-Pacific realms. A great reduction in reef coral diversity from 60-80 Oligocene species to 25-35 early Miocene species occurred in the Western Atlantic-Caribbean and Mediterranean areas accompanied by a decrease in reef growth. A slower and less drastic change apparently occurred in the Indo-Pacific area. Early Miocene reef corals of the Western Atlantic-Caribbean comprise a transition between the cosmopolitan Oligocene fauna and its endemic mid-Miocene to modern counterpart. Although early Miocene reefsmore » were dominated by a Porites-Montastrea assemblage, eastward flow of Pacific circulation brought with it ''exotic'' corals such as Coscinaraea and Pseudocolumnastrea. Also, many cosmopolitan genera persisted from the Oligocene. During the middle to late Miocene, most of the species still living on Holocene reefs evolved. As the Mediterranean basin became more restricted, there was a slow decline in reef corals from 20 - 25 species in the Aquitainian to less than five species in the Messinian. Eustatic lowstand led to the extinction of reef-building corals in the late Messinian. In the Indo-Pacific, Neogene evolution of reef corals was conservative. Excluding the Acroporidae and Seriatoporidae, most Holocene framework species had evolved by the middle Miocene. Interplay between regional tectonics and eustatic sea level changes led to extensive development of middle to late Miocene pinnacle reefs over the southwestern Pacific.« less

Self-recognition in corals facilitates deep-sea habitat engineering

USGS Publications Warehouse

Hennige, Sebastian J; Morrison, Cheryl L.; Form, Armin U.; Buscher, Janina; Kamenos, Nicholas A.; Roberts, J. Murray

2014-01-01

The ability of coral reefs to engineer complex three-dimensional habitats is central to their success and the rich biodiversity they support. In tropical reefs, encrusting coralline algae bind together substrates and dead coral framework to make continuous reef structures, but beyond the photic zone, the cold-water coral Lophelia pertusa also forms large biogenic reefs, facilitated by skeletal fusion. Skeletal fusion in tropical corals can occur in closely related or juvenile individuals as a result of non-aggressive skeletal overgrowth or allogeneic tissue fusion, but contact reactions in many species result in mortality if there is no ‘self-recognition’ on a broad species level. This study reveals areas of ‘flawless’ skeletal fusion in Lophelia pertusa, potentially facilitated by allogeneic tissue fusion, are identified as having small aragonitic crystals or low levels of crystal organisation, and strong molecular bonding. Regardless of the mechanism, the recognition of ‘self’ between adjacent L. pertusa colonies leads to no observable mortality, facilitates ecosystem engineering and reduces aggression-related energetic expenditure in an environment where energy conservation is crucial. The potential for self-recognition at a species level, and subsequent skeletal fusion in framework-forming cold-water corals is an important first step in understanding their significance as ecological engineers in deep-seas worldwide.

Systematic mapping of bedrock and habitats along the Florida reef tract: central Key Largo to Halfmoon Shoal (Gulf of Mexico)

USGS Publications Warehouse

Lidz, Barbara H.; Reich, Christopher D.; Shinn, Eugene A.

2007-01-01

The fragile coral reefs of the Florida Keys form the largest living coral reef ecosystem in the continental United States. Lining the shallow outer shelf approximately 5 to 7 km seaward of the keys, the reefs have national aesthetic and resource value. As recently as the 1970s, the coral reefs were the heart of a vibrant ecosystem. Since then, the health of all ecosystem components has declined markedly due to a variety of environmental stressors . Corals are succumbing to bleaching and diseases. Species that are the building blocks of solid reef framework are increasingly being replaced by species that do not construct reef framework. Algal proliferation is increasing competition for space and hard surfaces needed by coral larvae for settlement. Decline of the coral reef ecosystem has significant negative implications for economic vitality of the region, ranging from viability of the tourism industry attracted by the aesthetics to commercial fisheries drawn by the resources. At risk of loss are biologic habitats and reef resources, including interconnected habitats for endangered species in shoreline mangroves, productive nearshore marine and wetland nurseries, and economic offshore fisheries. In 1997, the U.S. Geological Survey's Coastal and Marine Geology Program undertook a comprehensive 7-year-long mission to consolidate, synthesize, and map new (1997) and existing geologic and biologic information into a digitized regional database and one-volume reference source on the geologic history of the Florida Keys reef tract (this report). The project was conducted in cooperation with the National Oceanic and Atmospheric Administration's National Marine Sanctuary Program. The purpose was to examine the natural evolution and demise of several coral reef ecosystems over the past 325,000 years, with an eye toward gaining a better understanding of the cause of the reef decline observed today. Scientific data and datasets presented in this report are intended for use by others in ongoing efforts to delineate which components of reef decline in the Florida Keys may be natural and which may be a result of human activities. Beyond scientific baseline datasets, this report also incorporates environmental, social, and historical aspects of the Florida Keys, including the impact of exploratory oil wells on benthic habitats off Florida.

Fragile Reefs of the Eastern Pacific: Does low Cementation Provide a Model for Reefs in a High CO2 World?

NASA Astrophysics Data System (ADS)

Manzello, D.; Kleypas, J.; Eakin, M.; Budd, D.

2007-05-01

Around the world, reefs will experience high pCO2, low pH, low carbonate concentrations, and low aragonite saturation state as atmospheric CO2 rises. Ocean carbon chemistry measurements show that eastern Pacific waters already exist at high pCO2 and low carbonate concentrations due to natural upwelling in the region. Because of the upwelling, this region may serve as a model for coral reef development under enhanced atmospheric CO2 and oceanic pCO2; that is, low coral growth, low secondary cementation, and high physical, chemical, and biological erosion. Reefs in the eastern Pacific Ocean are characterized by low biological diversity and relatively small size. Both past coring and recent analysis reveal that, while many reefs in the eastern Pacific are several thousand years old, they are fragile and lack significant cementation, even in the innermost, oldest structures. They are also extremely porous with high water throughflow. Without secondary cementation, branching coral frameworks are held together only by organically produced calcium carbonate (e.g. coralline algae), sponges, and other reef infauna, and contain a high proportion of loose sediments. The result is reef frameworks that are more susceptible to destruction from mechanical or biological erosion. The poorly cemented nature of eastern Pacific reefs is thus hypothesized to have been a factor in the severe bioerosion that occurred on these reefs after past bleaching events (1982-3, 1997-8). We will present data that indicate low rates of cementation and high rates of erosion on eastern Pacific coral reefs and will compare current carbonate chemistry in the eastern Pacific to model predictions of what reefs around the globe may experience in coming decades.

Incorporating benthic community changes into hydrochemical-based projections of coral reef calcium carbonate production under ocean acidification

NASA Astrophysics Data System (ADS)

Shaw, Emily C.; Hamylton, Sarah M.; Phinn, Stuart R.

2016-06-01

The existence of coral reefs is dependent on the production and maintenance of calcium carbonate (CaCO3) framework that is produced through calcification. The net production of CaCO3 will likely decline in the future, from both declining net calcification rates (decreasing calcification and increasing dissolution) and shifts in benthic community composition from calcifying organisms to non-calcifying organisms. Here, we present a framework for hydrochemical studies that allows both declining net calcification rates and changes in benthic community composition to be incorporated into projections of coral reef CaCO3 production. The framework involves upscaling net calcification rates for each benthic community type using mapped proportional cover of the benthic communities. This upscaling process was applied to the reef flats at One Tree and Lady Elliot reefs (Great Barrier Reef) and Shiraho Reef (Okinawa), and compared to existing data. Future CaCO3 budgets were projected for Lady Elliot Reef, predicting a decline of 53 % from the present value by end-century (800 ppm CO2) without any changes to benthic community composition. A further 5.7 % decline in net CaCO3 production is expected for each 10 % decline in calcifier cover, and net dissolution is predicted by end-century if calcifier cover drops below 18 % of the present extent. These results show the combined negative effect of both declining net calcification rates and changing benthic community composition on reefs and the importance of considering both processes for determining future reef CaCO3 production.

Evaluation of coral reef carbonate production models at a global scale

NASA Astrophysics Data System (ADS)

Jones, N. S.; Ridgwell, A.; Hendy, E. J.

2014-09-01

Calcification by coral reef communities is estimated to account for half of all carbonate produced in shallow water environments and more than 25% of the total carbonate buried in marine sediments globally. Production of calcium carbonate by coral reefs is therefore an important component of the global carbon cycle. It is also threatened by future global warming and other global change pressures. Numerical models of reefal carbonate production are essential for understanding how carbonate deposition responds to environmental conditions including future atmospheric CO2 concentrations, but these models must first be evaluated in terms of their skill in recreating present day calcification rates. Here we evaluate four published model descriptions of reef carbonate production in terms of their predictive power, at both local and global scales, by comparing carbonate budget outputs with independent estimates. We also compile available global data on reef calcification to produce an observation-based dataset for the model evaluation. The four calcification models are based on functions sensitive to combinations of light availability, aragonite saturation (Ωa) and temperature and were implemented within a specifically-developed global framework, the Global Reef Accretion Model (GRAM). None of the four models correlated with independent rate estimates of whole reef calcification. The temperature-only based approach was the only model output to significantly correlate with coral-calcification rate observations. The absence of any predictive power for whole reef systems, even when consistent at the scale of individual corals, points to the overriding importance of coral cover estimates in the calculations. Our work highlights the need for an ecosystem modeling approach, accounting for population dynamics in terms of mortality and recruitment and hence coral cover, in estimating global reef carbonate budgets. In addition, validation of reef carbonate budgets is severely hampered by limited and inconsistent methodology in reef-scale observations.

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

NASA Astrophysics Data System (ADS)

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

2010-06-01

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

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

NASA Astrophysics Data System (ADS)

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

2013-12-01

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

A Decision Support Framework for Science-Based, Multi-Stakeholder Deliberation: A Coral Reef Example

NASA Astrophysics Data System (ADS)

Rehr, Amanda P.; Small, Mitchell J.; Bradley, Patricia; Fisher, William S.; Vega, Ann; Black, Kelly; Stockton, Tom

2012-12-01

We present a decision support framework for science-based assessment and multi-stakeholder deliberation. The framework consists of two parts: a DPSIR (Drivers-Pressures-States-Impacts-Responses) analysis to identify the important causal relationships among anthropogenic environmental stressors, processes, and outcomes; and a Decision Landscape analysis to depict the legal, social, and institutional dimensions of environmental decisions. The Decision Landscape incorporates interactions among government agencies, regulated businesses, non-government organizations, and other stakeholders. It also identifies where scientific information regarding environmental processes is collected and transmitted to improve knowledge about elements of the DPSIR and to improve the scientific basis for decisions. Our application of the decision support framework to coral reef protection and restoration in the Florida Keys focusing on anthropogenic stressors, such as wastewater, proved to be successful and offered several insights. Using information from a management plan, it was possible to capture the current state of the science with a DPSIR analysis as well as important decision options, decision makers and applicable laws with a the Decision Landscape analysis. A structured elicitation of values and beliefs conducted at a coral reef management workshop held in Key West, Florida provided a diversity of opinion and also indicated a prioritization of several environmental stressors affecting coral reef health. The integrated DPSIR/Decision landscape framework for the Florida Keys developed based on the elicited opinion and the DPSIR analysis can be used to inform management decisions, to reveal the role that further scientific information and research might play to populate the framework, and to facilitate better-informed agreement among participants.

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.

Breathing of a coral cay: Tracing tidally driven seawater recirculation in permeable coral reef sediments

NASA Astrophysics Data System (ADS)

Santos, Isaac R.; Erler, Dirk; Tait, Douglas; Eyre, Bradley D.

2010-12-01

Coral reefs are characterized by high gross productivity in spite of low nutrient concentrations. This apparent paradox may be partially reconciled if seawater recirculation in permeable sediments over large (meters) and long (hours to days) scales is an important source of recycled nitrogen and phosphorus to coral reefs. In this paper we use radon (222Rn, a natural tracer) to quantify tidally driven pore water (or groundwater) exchange between (1) an offshore coral cay island and its fringing reef lagoon and (2) a reef lagoon and the surrounding ocean. As seawater infiltrates Heron Island at high tide, it acquires a radon signal that can be detected when pore waters emerge from carbonate sands at low tide. A nonsteady state model indicated that vertical pore water upwelling rates (or saline submarine groundwater discharge) were >40 cm/d within the reef lagoon and >100 cm/d outside the lagoon at low tide. Within the lagoon, tidal pumping and temperature-driven convection were the main driving forces of pore water advection. At low tide, the reef lagoon level is about 1 m higher than the surrounding ocean. As a result, a steep hydraulic gradient develops at the reef edge, driving unidirectional filtration through the reef framework. Groundwaters were highly enriched in nitrate (average of 530 μmol, likely influenced by bird guano) relative to lagoon waters (1.9 μmol). Rough but conservative estimates indicated that groundwater-derived nitrate fluxes (7.9 mmol/m2/d) can replace the entire lagoon nitrate inventory every <19 days. We speculate that as offshore coral islands "breath" (inhale seawater at high tide and exhale groundwater at low tide), they release nutrients that lead to sustained productivity within coral reefs.

A linked land-sea modeling framework to inform ridge-to-reef management in high oceanic islands

EPA Science Inventory

Declining natural resources have led to a cultural renaissance across the Pacific that seeks to revive customary ridge-to-reef management approaches to protect freshwater and restore abundant coral reef fisheries. Effective ridge-to-reef management requires improved understanding...

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

NASA Astrophysics Data System (ADS)

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

2007-12-01

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

CORAL DISEASE & HEALTH CONSORTIUM: FINDING SOLUTIONS

EPA Science Inventory

The National Oceanic Atmospheric Administration (NOAA), the Environmental Protection Agency (EPA), and the Department of Interior (DOI) developed the framework for a Coral Disease and Health Consortium (CDHC) for the United States Coral Reef Task Force (USCRTF) through an interag...

Climate warming, marine protected areas and the ocean-scale integrity of coral reef ecosystems.

PubMed

Graham, Nicholas A J; McClanahan, Tim R; MacNeil, M Aaron; Wilson, Shaun K; Polunin, Nicholas V C; Jennings, Simon; Chabanet, Pascale; Clark, Susan; Spalding, Mark D; Letourneur, Yves; Bigot, Lionel; Galzin, René; Ohman, Marcus C; Garpe, Kajsa C; Edwards, Alasdair J; Sheppard, Charles R C

2008-08-27

Coral reefs have emerged as one of the ecosystems most vulnerable to climate variation and change. While the contribution of a warming climate to the loss of live coral cover has been well documented across large spatial and temporal scales, the associated effects on fish have not. Here, we respond to recent and repeated calls to assess the importance of local management in conserving coral reefs in the context of global climate change. Such information is important, as coral reef fish assemblages are the most species dense vertebrate communities on earth, contributing critical ecosystem functions and providing crucial ecosystem services to human societies in tropical countries. Our assessment of the impacts of the 1998 mass bleaching event on coral cover, reef structural complexity, and reef associated fishes spans 7 countries, 66 sites and 26 degrees of latitude in the Indian Ocean. Using Bayesian meta-analysis we show that changes in the size structure, diversity and trophic composition of the reef fish community have followed coral declines. Although the ocean scale integrity of these coral reef ecosystems has been lost, it is positive to see the effects are spatially variable at multiple scales, with impacts and vulnerability affected by geography but not management regime. Existing no-take marine protected areas still support high biomass of fish, however they had no positive affect on the ecosystem response to large-scale disturbance. This suggests a need for future conservation and management efforts to identify and protect regional refugia, which should be integrated into existing management frameworks and combined with policies to improve system-wide resilience to climate variation and change.

Ocean acidification and warming will lower coral reef resilience

PubMed Central

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

2011-01-01

Ocean warming and acidification from increasing levels of atmospheric CO2 represent major global threats to coral reefs, and are in many regions exacerbated by local-scale disturbances such as overfishing and nutrient enrichment. Our understanding of global threats and local-scale disturbances on reefs is growing, but their relative contribution to reef resilience and vulnerability in the future is unclear. Here, we analyse quantitatively how different combinations of CO2 and fishing pressure on herbivores will affect the ecological resilience of a simplified benthic reef community, as defined by its capacity to maintain and recover to coral-dominated states. We use a dynamic community model integrated with the growth and mortality responses for branching corals (Acropora) and fleshy macroalgae (Lobophora). We operationalize the resilience framework by parameterizing the response function for coral growth (calcification) by ocean acidification and warming, coral bleaching and mortality by warming, macroalgal mortality by herbivore grazing and macroalgal growth via nutrient loading. The model was run for changes in sea surface temperature and water chemistry predicted by the rise in atmospheric CO2 projected from the IPCC's fossil-fuel intensive A1FI scenario during this century. Results demonstrated that severe acidification and warming alone can lower reef resilience (via impairment of coral growth and increased coral mortality) even under high grazing intensity and low nutrients. Further, the threshold at which herbivore overfishing (reduced grazing) leads to a coral–algal phase shift was lowered by acidification and warming. These analyses support two important conclusions: Firstly, reefs already subjected to herbivore overfishing and nutrification are likely to be more vulnerable to increasing CO2. Secondly, under CO2 regimes above 450–500 ppm, management of local-scale disturbances will become critical to keeping reefs within an Acropora-rich domain.

How accessible are coral reefs to people? A global assessment based on travel time.

PubMed

Maire, Eva; Cinner, Joshua; Velez, Laure; Huchery, Cindy; Mora, Camilo; Dagata, Stephanie; Vigliola, Laurent; Wantiez, Laurent; Kulbicki, Michel; Mouillot, David

2016-04-01

The depletion of natural resources has become a major issue in many parts of the world, with the most accessible resources being most at risk. In the terrestrial realm, resource depletion has classically been related to accessibility through road networks. In contrast, in the marine realm, the impact on living resources is often framed into the Malthusian theory of human density around ecosystems. Here, we develop a new framework to estimate the accessibility of global coral reefs using potential travel time from the nearest human settlement or market. We show that 58% of coral reefs are located < 30 min from the nearest human settlement. We use a case study from New Caledonia to demonstrate that travel time from the market is a strong predictor of fish biomass on coral reefs. We also highlight a relative deficit of protection on coral reef areas near people, with disproportional protection on reefs far from people. This suggests that conservation efforts are targeting low-conflict reefs or places that may already be receiving de facto protection due to their isolation. Our global assessment of accessibility in the marine realm is a critical step to better understand the interplay between humans and resources. © 2016 John Wiley & Sons Ltd/CNRS.

Coral seas in fifty years: Need for local policies

NASA Astrophysics Data System (ADS)

Longley, P.; Cheng, N. S.; Fontaine, R. M.; Horton, K.; Bhattacharya, A.

2017-12-01

Arising stressors from both global and local sources threaten coral reefs, with studies indicating that local and global sources might reduce coral resilience. Local sources include sediment stress and nutrient stress from fishing; global sources include increasing sea surface temperature and ocean acidification. Through an in-depth review and re-analysis of published work, conducted under the scope of a course in the spring of 2017 semester and follow up research over the summer of 2017 and fall of 2017, students in Environmental Studies Course, ENVS 4100: Coral reefs, at the University of Colorado Boulder have developed a framework to initiate a discussion of global and local policies focused on protection of coral reefs. The research aims to assess current threats and suggest mitigation efforts. The paper uses secondary research to analyze impact of ocean acidification on aragonite saturation levels, current thermal stress, nutrient stress, and sediment factors that influence the health of coral and its surrounding ecosystem over the Common Era. Case studies in this paper include the Caribbean and Red Sea coral reefs, due to the variation of the atmosphere, temperature, and human activity in these regions. This paper intends to offer sufficient evidence that will lead to appropriate policy decisions that pertain to reef conservation.

A study on the recovery of Tobago's coral reefs following the 2010 mass bleaching event.

PubMed

Buglass, Salome; Donner, Simon D; Alemu I, Jahson B

2016-03-15

In 2010, severe coral bleaching was observed across the southeastern Caribbean, including the island of Tobago, where coral reefs are subject to sedimentation and high nutrient levels from terrestrial runoff. Here we examine changes in corals' colony size distributions over time (2010-2013), juvenile abundances and sedimentation rates for sites across Tobago following the 2010 bleaching event. The results indicated that since pre-bleaching coral cover was already low due to local factors and past disturbance, the 2010 event affected only particular susceptible species' population size structure and increased the proportion of small sized colonies. The low density of juveniles (mean of 5.4±6.3 juveniles/m(-2)) suggests that Tobago's reefs already experienced limited recruitment, especially of large broadcasting species. The juvenile distribution and the response of individual species to the bleaching event support the notion that Caribbean reefs are becoming dominated by weedy non-framework building taxa which are more resilient to disturbances. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Kauffman, E.G.

Throughout the Mesozoic, shallow-water carbonate ramps and platforms of the circumequatorial Tethyan Ocean were characterized by extensive development of reef ecosystems, especially during times of eustatic highstand, expansion of the Tropics, and warm equable global climates. The greatest reef development was north of the paleoequator in the Caribbean and Indo-Mediterranean provinces. These reefs and associated debris facies comprise major petroleum reservoirs, in some cases with remarkable porosity and permeability normally attributed to a combination of sedimentologic, tectonic, and diagenetic factors. The biological evolution of Mesozoic reefs also has had an important, and in some cases dominant, role in determining reservoirmore » quality. Three major biological factors are critical to mesozoic reef-associated reservoir development: (1) the replacement/competitive displacement of coral-algal dominated, highly integrated reef ecosystems by loosely packed rudistid bivalve-dominated reef ecosystems in the Barremian-Albian; (2) the evolution of dominantly aragonitic, highly porous shells among framework-building rudistids in the middle and Late Cretaceous; and (3) competitive strategies among rudistids that effectively prevented widespread biological binding of Cretaceous reefs, leading to the production of large marginal fans that comprise major carbonate reservoirs. Detailed studies of these evolutionary trends in reef/framework development and of the distribution of different groups of bioconstructors on reefs lead to predictive modeling for primary and secondary porosity development in mesozoic carbonate reservoirs. The competitive displacement of coral-algal communities by rudistids on Cretaceous reefs was so effective that, even after Maastrichtian mass extinction of rudistids and other important groups comprising Mesozoic reef/carbonate platform ecosystems, coral-algal reef-building communities did not evolve again until the late Eocene.« less

Translational environmental biology: cell biology informing conservation.

PubMed

Traylor-Knowles, Nikki; Palumbi, Stephen R

2014-05-01

Typically, findings from cell biology have been beneficial for preventing human disease. However, translational applications from cell biology can also be applied to conservation efforts, such as protecting coral reefs. Recent efforts to understand the cell biological mechanisms maintaining coral health such as innate immunity and acclimatization have prompted new developments in conservation. Similar to biomedicine, we urge that future efforts should focus on better frameworks for biomarker development to protect coral reefs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Retrograde accretion of a Caribbean fringing reef controlled by hurricanes and sea-level rise

NASA Astrophysics Data System (ADS)

Blanchon, Paul; Richards, Simon; Bernal, Juan Pablo; Cerdeira-Estrada, Sergio; Ibarra, M. Socrates; Corona-Martínez, Liliana; Martell-Dubois, Raúl

2017-10-01

Predicting the impact of sea-level (SL) rise on coral reefs requires reliable models of reef accretion. Most assume that accretion results from vertical growth of coralgal framework, but recent studies show that reefs exposed to hurricanes consist of layers of coral gravel rather than in-place corals. New models are therefore needed to account for hurricane impact on reef accretion over geological timescales. To investigate this geological impact, we report the configuration and development of a 4-km-long fringing reef at Punta Maroma along the northeast Yucatan Peninsula. Satellite-derived bathymetry shows the crest is set-back a uniform distance of 315 ±15 m from a mid-shelf slope break, and the reef-front decreases 50% in width and depth along its length. A 12-core drill transect constrained by multiple 230Th ages shows the reef is composed of an 2-m thick layer of coral clasts that has retrograded 100 m over its back-reef during the last 5.5 ka. These findings are consistent with a hurricane-control model of reef development where large waves trip and break over the mid-shelf slope break, triggering rapid energy dissipation and thus limiting how far upslope individual waves can fragment corals and redistribute clasts. As SL rises and water depth increases, energy dissipation during wave-breaking is reduced, extending the clast-transport limit, thus leading to reef retrogradation. This hurricane model may be applicable to a large sub-set of fringing reefs in the tropical Western-Atlantic necessitating a reappraisal of their accretion rates and response to future SL rise.

Assessing baseline levels of coral health in a newly established marine protected area in a global scuba diving hotspot.

PubMed

Hein, Margaux Y; Lamb, Joleah B; Scott, Chad; Willis, Bette L

2015-02-01

While coral reefs are increasingly threatened worldwide, they are also increasingly used for recreational activities. Given the environmental and socio-economic significance of coral reefs, understanding the links between human activities and coral health and evaluating the efficacy of marine protected areas (MPAs) as a management regime to prevent further deterioration are critically important. The aim of this study was to quantify indicators of coral health at sites inside and outside a newly rezoned MPA framework in the dive tourism hotspot of Koh Tao, Thailand. We found that patterns in the health and diversity of coral communities one year on did not reflect the protected status conferred by newly zoned MPAs, but instead reflected past history of recreational use around the island. Sites characterised as past high-use sites had lower mean percent cover of hard corals overall and of corals in the typically disease- and disturbance-susceptible family Acroporidae, but higher mean cover of species in the more weedy family Agariciidae. Past high use sites also had higher mean prevalence of infectious diseases and other indicators of compromised health. Sites within the newly established MPAs are currently subjected to higher levels of environmental and anthropogenic pressures, with sedimentation, algal overgrowth, feeding scars from Drupella snails, and breakage particularly prevalent compared to sites in non-MPA areas. Given the greater prevalence of these factors within protected sites, the capacity of the MPA framework to effectively prevent further deterioration of Koh Tao's reefs is unclear. Nevertheless, our study constitutes a strong baseline for future long-term evaluations of the potential of MPAs to maintain coral health and diversity on highly threatened reefs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Budget of coral-derived organic carbon in a fringing coral reef of the Gulf of Aqaba, Red Sea

NASA Astrophysics Data System (ADS)

Naumann, Malik S.; Richter, Claudio; Mott, Claudius; el-Zibdah, Mohammad; Manasrah, Riyad; Wild, Christian

2012-12-01

The continuous release of organic C-rich material by reef-building corals can contribute substantially to biogeochemical processes and concomitant rapid nutrient recycling in coral reef ecosystems. However, our current understanding of these processes is limited to platform reefs exhibiting a high degree of ecosystem closure compared to the globally most common fringing reef type. This study carried out in the northern Gulf of Aqaba (Red Sea) presents the first quantitative budget for coral-derived organic carbon (COC) in a fringing reef and highlights the importance of local hydrodynamics. Diel reef-wide COC release amounted to 1.1 ± 0.2 kmol total organic carbon (TOC) representing 1-3% of gross benthic primary production. Most COC (73%) was released as particulate organic C (POC), the bulk of which (34-63%) rapidly settled as mucus string aggregates accounting for approximately 28% of total POC sedimentation. Sedimentation of mucus strings, but also dilution of suspended and dissolved COC in reef waters retained 82% of diel COC release in the fringing reef, providing a potentially important organic source for a COC-based food web. Pelagic COC degradation represented 0.1-1.6% of pelagic microbial respiration recycling 32% of diel retained COC. Benthic COC degradation contributed substantially (29-47%) to reef-wide microbial respiration in reef sands, including 20-38% by mucus string POC, and consumed approximately 52% of all retained COC. These findings point out the importance of COC as a C carrier for different reef types. COC may further represent a source of organic carbon for faunal communities colonising reef framework cavities complementing the efficient retention and recycling of COC within fringing reef environments.

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

NASA Astrophysics Data System (ADS)

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

2016-07-01

The inner shelf Kimberley Bioregion of Northwest Australia is characterised by a macrotidal setting where prolific coral reefs growth as developed around a complex drowned landscape and is considered a biodiversity "hotspot". High-resolution shallow seismic studies were conducted across various reef settings in the Kimberley (Buccaneer Archipelago, north of Dampier Peninsula, latitude: between 16°40‧S and 16°00‧S) to evaluate stratigraphic evolution, interaction with different substrates, morphological patterns and distribution. Reef sites were chosen to assess most of the reef types present, particularly high intertidal planar reefs and fringing reefs. Reef internal acoustic reflectors were identified according to their shape, stratigraphic position and characteristics. Two main seismic horizons were identified marking the boundaries between Holocene reef (Marine Isotope Stage 1, MIS 1, last 12 ky), commonly 10-20 m thick, and MIS 5 (Last Interglacial, LIG, ~120 ky, up to 12 m thick) and Proterozoic rock foundation over which Quaternary reef growth occurred. Within the Holocene Reef unit, at least three minor internal reflectors, generally discontinuous, subparallel to the reef flat were recognised and interpreted as either growth hiatuses or a change of the coral framework or sediment matrix. The LIG reefs represent a new northernmost occurrence along the Western Australian coast. The research presented here achieved the first regional geophysical study of the Kimberley reefs. Subbottom profiles demonstrated that the surveyed reefs are characterised by a multi-stage reef buildup, indicating that coral growth occurred in the Kimberley during previous sea level highstands. The data show also that antecedent substrate and regional subsidence have contributed, too, in determining the amount of accommodation available for reef growth and controlling the morphology of the successive reef building stages. Moreover, the study showed that in spite of macrotidal conditions, high-turbidity and frequent high-energy cyclonic events, corals have exhibited prolific reef growth during the Holocene developing significant reef accretionary structures. As a result coral reefs have generating habitat complexity and species diversity in what is a biodiversity hotspot.

Tracing carbon flow through coral reef food webs using a compound-specific stable isotope approach.

PubMed

McMahon, Kelton W; Thorrold, Simon R; Houghton, Leah A; Berumen, Michael L

2016-03-01

Coral reefs support spectacularly productive and diverse communities in tropical and sub-tropical waters throughout the world's oceans. Debate continues, however, on the degree to which reef biomass is supported by new water column production, benthic primary production, and recycled detrital carbon (C). We coupled compound-specific stable C isotope ratio (δ(13)C) analyses with Bayesian mixing models to quantify C flow from primary producers to coral reef fishes across multiple feeding guilds and trophic positions in the Red Sea. Analyses of reef fishes with putative diets composed primarily of zooplankton (Amblyglyphidodon indicus), benthic macroalgae (Stegastes nigricans), reef-associated detritus (Ctenochaetus striatus), and coral tissue (Chaetodon trifascialis) confirmed that δ(13)C values of essential amino acids from all baseline C sources were both isotopically diagnostic and accurately recorded in consumer tissues. While all four source end-members contributed to the production of coral reef fishes in our study, a single-source end-member often dominated dietary C assimilation of a given species, even for highly mobile, generalist top predators. Microbially reworked detritus was an important secondary C source for most species. Seascape configuration played an important role in structuring resource utilization patterns. For instance, Lutjanus ehrenbergii showed a significant shift from a benthic macroalgal food web on shelf reefs (71 ± 13 % of dietary C) to a phytoplankton-based food web (72 ± 11 %) on oceanic reefs. Our work provides insights into the roles that diverse C sources play in the structure and function of coral reef ecosystems and illustrates a powerful fingerprinting method to develop and test nutritional frameworks for understanding resource utilization.

Sedimentologic succession of uplifted coral community, Urvina Bay, Isabela Island, Galapagos Archipelago, Ecuador

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

Colgan, M.W.; Hollander, D.

1987-05-01

In March 1954, along the west-central coast of Isabela Island, an upward movement of magma suddenly raised Urvina Bay over 6 m and exposed several square kilometers of carbonate deposits covering a young aa lava flow (around 1000 years old). Results from 6 transect lines across the uplift, 30 cores, and 10 trenches describe the sedimentologic and ecologic transition from barren basalt to diverse carbonate sediments with small coral reefs. Along horizontal transects spanning from 0 to 7 m paleowater depth, there is a seaward progression from beaches, mangroves, and basalt to thick deposits (> 1.6 m) of carbonate sandsmore » and small coral reefs. Variation in water depth, degree of wave exposure, and irregularity of the aa lava topography provided many microhabitats where coral, calcareous algae, and mollusks settled and grew. Eight hermatypic coral species are found throughout the shelf, and three species (i.e., Pavona clavus, Pocillopora damicornis, and Porites lobata) produced five small, isolated, monospecific, coral-reef frameworks. The vertical section seen in cores and trenches shows that calcium carbonate increased upward, whereas volcanic sediments decreased; however, episodic layers occur with high concentrations of basaltic sands. In vertical samples from the central portion of the shelf, the coral population changed from small, isolated colonies of Psammocora (Plesioseris) superficalis near the basalt basement to large reef-forming colonies of Pocillopora damicornis farther upsection. Reefs of the Galapagos Islands are small and less diverse than most Pacific reefs. Nonetheless, understanding their temporal successional development should throw light on the origin and history of larger oceanic reefs in the Pacific.« less

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

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

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

Framework of barrier reefs threatened by ocean acidification.

PubMed

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

2016-03-01

To date, studies of ocean acidification (OA) on coral reefs have focused on organisms rather than communities, and the few community effects that have been addressed have focused on shallow back reef habitats. The effects of OA on outer barrier reefs, which are the most striking of coral reef habitats and are functionally and physically different from back reefs, are unknown. Using 5-m long outdoor flumes to create treatment conditions, we constructed coral reef communities comprised of calcified algae, corals, and reef pavement that were assembled to match the community structure at 17 m depth on the outer barrier reef of Moorea, French Polynesia. Communities were maintained under ambient and 1200 μatm pCO2 for 7 weeks, and net calcification rates were measured at different flow speeds. Community net calcification was significantly affected by OA, especially at night when net calcification was depressed ~78% compared to ambient pCO2 . Flow speed (2-14 cm s(-1) ) enhanced net calcification only at night under elevated pCO2 . Reef pavement also was affected by OA, with dissolution ~86% higher under elevated pCO2 compared to ambient pCO2 . These results suggest that net accretion of outer barrier reef communities will decline under OA conditions predicted within the next 100 years, largely because of increased dissolution of reef pavement. Such extensive dissolution poses a threat to the carbonate foundation of barrier reef communities. © 2015 John Wiley & Sons Ltd.

Extinction vulnerability of coral reef fishes.

PubMed

Graham, Nicholas A J; Chabanet, Pascale; Evans, Richard D; Jennings, Simon; Letourneur, Yves; Aaron Macneil, M; McClanahan, Tim R; Ohman, Marcus C; Polunin, Nicholas V C; Wilson, Shaun K

2011-04-01

With rapidly increasing rates of contemporary extinction, predicting extinction vulnerability and identifying how multiple stressors drive non-random species loss have become key challenges in ecology. These assessments are crucial for avoiding the loss of key functional groups that sustain ecosystem processes and services. We developed a novel predictive framework of species extinction vulnerability and applied it to coral reef fishes. Although relatively few coral reef fishes are at risk of global extinction from climate disturbances, a negative convex relationship between fish species locally vulnerable to climate change vs. fisheries exploitation indicates that the entire community is vulnerable on the many reefs where both stressors co-occur. Fishes involved in maintaining key ecosystem functions are more at risk from fishing than climate disturbances. This finding is encouraging as local and regional commitment to fisheries management action can maintain reef ecosystem functions pending progress towards the more complex global problem of stabilizing the climate. © 2011 Blackwell Publishing Ltd/CNRS.

Extinction vulnerability of coral reef fishes

PubMed Central

Graham, Nicholas A J; Chabanet, Pascale; Evans, Richard D; Jennings, Simon; Letourneur, Yves; Aaron MacNeil, M; McClanahan, Tim R; Öhman, Marcus C; Polunin, Nicholas V C; Wilson, Shaun K

2011-01-01

With rapidly increasing rates of contemporary extinction, predicting extinction vulnerability and identifying how multiple stressors drive non-random species loss have become key challenges in ecology. These assessments are crucial for avoiding the loss of key functional groups that sustain ecosystem processes and services. We developed a novel predictive framework of species extinction vulnerability and applied it to coral reef fishes. Although relatively few coral reef fishes are at risk of global extinction from climate disturbances, a negative convex relationship between fish species locally vulnerable to climate change vs. fisheries exploitation indicates that the entire community is vulnerable on the many reefs where both stressors co-occur. Fishes involved in maintaining key ecosystem functions are more at risk from fishing than climate disturbances. This finding is encouraging as local and regional commitment to fisheries management action can maintain reef ecosystem functions pending progress towards the more complex global problem of stabilizing the climate. PMID:21320260

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

NASA Astrophysics Data System (ADS)

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

2013-05-01

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

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.

Controls on coral-ground development along the northern Mesoamerican Reef tract.

PubMed

Rodríguez-Martínez, Rosa E; Jordán-Garza, Adán G; Maldonado, Miguel A; Blanchon, Paul

2011-01-01

Coral-grounds are reef communities that colonize rocky substratum but do not form framework or three-dimensional reef structures. To investigate why, we used video transects and underwater photography to determine the composition, structure and status of a coral-ground community located on the edge of a rocky terrace in front of a tourist park, Xcaret, in the northern Mesoamerican Reef tract, Mexico. The community has a relatively low coral, gorgonian and sponge cover (<10%) and high algal cover (>40%). We recorded 23 species of Scleractinia, 14 species of Gorgonacea and 30 species of Porifera. The coral community is diverse but lacks large coral colonies, being dominated instead by small, sediment-tolerant, and brooding species. In these small colonies, the abundance of potentially lethal interactions and partial mortality is high but decreases when colonies are larger than 40 cm. Such characteristics are consistent with an environment control whereby storm waves periodically remove larger colonies and elevate sediment flux. The community only survives these storm conditions due to its slope-break location, which ensures lack of burial and continued local recruitment. A comparison with similar coral-ground communities in adjacent areas suggests that the narrow width of the rock terrace hinders sediment stabilization, thereby ensuring that communities cannot escape bottom effects and develop into three-dimensional reef structures on geological time scales.

Enhanced acidification of global coral reefs driven by regional biogeochemical feedbacks

NASA Astrophysics Data System (ADS)

Cyronak, Tyler; Schulz, Kai G.; Santos, Isaac R.; Eyre, Bradley D.

2014-08-01

Physical uptake of anthropogenic CO2 is the dominant driver of ocean acidification (OA) in the open ocean. Due to expected decreases in calcification and increased dissolution of CaCO3 framework, coral reefs are thought to be highly susceptible to OA. However, biogeochemical processes can influence the pCO2 and pH of coastal ecosystems on diel and seasonal time scales, potentially modifying the long-term effects of increasing atmospheric CO2. By compiling data from the literature and removing the effects of short-term variability, we show that the average pCO2 of coral reefs throughout the globe has increased ~3.5-fold faster than in the open ocean over the past 20 years. This rapid increase in pCO2 has the potential to enhance the acidification and predicted effects of OA on coral reef ecosystems. A simple model demonstrates that potential drivers of elevated pCO2 include additional anthropogenic disturbances beyond increasing global atmospheric CO2 such as enhanced nutrient and organic matter inputs.

Fish larval recruitment to reefs is a thyroid hormone-mediated metamorphosis sensitive to the pesticide chlorpyrifos

PubMed Central

Lambert, Anne; François, Loïc; Barth, Paul; Gillet, Benjamin; Hughes, Sandrine; Piganeau, Gwenaël; Leulier, Francois; Viriot, Laurent

2017-01-01

Larval recruitment, the transition of pelagic larvae into reef-associated juveniles, is a critical step for the resilience of marine fish populations but its molecular control is unknown. Here, we investigate whether thyroid-hormones (TH) and their receptors (TR) coordinate the larval recruitment of the coral-reef-fish Acanthurus triostegus. We demonstrate an increase of TH-levels and TR-expressions in pelagic-larvae, followed by a decrease in recruiting juveniles. We generalize these observations in four other coral reef-fish species. Treatments with TH or TR-antagonist, as well as relocation to the open-ocean, disturb A. triostegus larvae transformation and grazing activity. Likewise, chlorpyrifos, a pesticide often encountered in coral-reefs, impairs A. triostegus TH-levels, transformation, and grazing activity, hence diminishing this herbivore’s ability to control the spread of reef-algae. Larval recruitment therefore corresponds to a TH-controlled metamorphosis, sensitive to endocrine disruption. This provides a framework to understand how larval recruitment, critical to reef-ecosystems maintenance, is altered by anthropogenic stressors. PMID:29083300

Expanded Florida reef development during the mid-Pliocene warm period

NASA Astrophysics Data System (ADS)

Klaus, James S.; Meeder, John F.; McNeill, Donald F.; Woodhead, Jon F.; Swart, Peter K.

2017-05-01

The coral fauna of the Tamiami Formation documents a northern expansion of reef development along the Florida Peninsula during the mid-Pliocene warm period (MPWP). Radiometric dating (U-Pb) of Solenastrea bournoni produced an age of 2.99 ± 0.11 Ma, constraining reef development to the MPWP and the peak of Plio-Pleistocene faunal turnover; subsequent to the final closure of the Central American Seaway (CAS) but prior to major Northern Hemisphere Glaciation (NHG). Coral faunal analyses are based on a total of 1614 coral specimens collected along a 165 km stretch of the west Florida coast, and included rarefaction and detrended correspondence analysis (DCA). A total of 60 coral species occur within the Tamiami Formation, with faunal assemblages ranging from 42 to 87% extinct taxa. The Tamiami collections can be split into a southern "reef" assemblage with high diversity of stenotopic taxa and a northern "non-reef" assemblage with lower diversity eurytopic taxa. The southern reef assemblage contains framework buildups of the dominant tropical taxa Stylophora affinis, Orbicella annularis, and Acropora cervicornis. We interpret enhanced west Florida reef development during the middle Pliocene to be a product of more equitable sea surface temperatures, and reduced salinity fluctuations associated with higher sea levels. While mean sea surface temperature estimates based on oxygen isotopic analysis of the coral Solenastrea bournoni (25.3 °C) are similar to present day values (26 °C), a completely flooded southern Florida Platform in the Pliocene would be less prone to salinity fluctuations associated with coastal runoff and extreme cold-water events during winter storms. While higher latitude range shifts of tropical reef corals associated with current global climate change have been documented elsewhere in the world, we do not foresee the West Florida Shelf being conducive to significant range shifts in tropical coral taxa or reef development within the coming century.

Evaluation of coral reef carbonate production models at a global scale

NASA Astrophysics Data System (ADS)

Jones, N. S.; Ridgwell, A.; Hendy, E. J.

2015-03-01

Calcification by coral reef communities is estimated to account for half of all carbonate produced in shallow water environments and more than 25% of the total carbonate buried in marine sediments globally. Production of calcium carbonate by coral reefs is therefore an important component of the global carbon cycle; it is also threatened by future global warming and other global change pressures. Numerical models of reefal carbonate production are needed for understanding how carbonate deposition responds to environmental conditions including atmospheric CO2 concentrations in the past and into the future. However, before any projections can be made, the basic test is to establish model skill in recreating present-day calcification rates. Here we evaluate four published model descriptions of reef carbonate production in terms of their predictive power, at both local and global scales. We also compile available global data on reef calcification to produce an independent observation-based data set for the model evaluation of carbonate budget outputs. The four calcification models are based on functions sensitive to combinations of light availability, aragonite saturation (Ωa) and temperature and were implemented within a specifically developed global framework, the Global Reef Accretion Model (GRAM). No model was able to reproduce independent rate estimates of whole-reef calcification, and the output from the temperature-only based approach was the only model to significantly correlate with coral-calcification rate observations. The absence of any predictive power for whole reef systems, even when consistent at the scale of individual corals, points to the overriding importance of coral cover estimates in the calculations. Our work highlights the need for an ecosystem modelling approach, accounting for population dynamics in terms of mortality and recruitment and hence calcifier abundance, in estimating global reef carbonate budgets. In addition, validation of reef carbonate budgets is severely hampered by limited and inconsistent methodology in reef-scale observations.

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

PubMed Central

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

2017-01-01

Hard coral cover on the Great Barrier Reef (GBR) is on a trajectory of decline. However, little is known about past coral mortality before the advent of long-term monitoring (circa 1980s). Using paleoecological analysis and high-precision uranium-thorium (U-Th) dating, we reveal an extensive loss of branching Acropora corals and changes in coral community structure in the Palm Islands region of the central GBR over the past century. In 2008, dead coral assemblages were dominated by large, branching Acropora and living coral assemblages by genera typically found in turbid inshore environments. The timing of Acropora mortality was found to be occasionally synchronous among reefs and frequently linked to discrete disturbance events, occurring in the 1920s to 1960s and again in the 1980s to 1990s. Surveys conducted in 2014 revealed low Acropora cover (<5%) across all sites, with very little evidence of change for up to 60 y at some sites. Collectively, our results suggest a loss of resilience of this formerly dominant key framework builder at a regional scale, with recovery severely lagging behind predictions. Our study implies that the management of these reefs may be predicated on a shifted baseline. PMID:28893981

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

PubMed

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

2017-09-26

Hard coral cover on the Great Barrier Reef (GBR) is on a trajectory of decline. However, little is known about past coral mortality before the advent of long-term monitoring (circa 1980s). Using paleoecological analysis and high-precision uranium-thorium (U-Th) dating, we reveal an extensive loss of branching Acropora corals and changes in coral community structure in the Palm Islands region of the central GBR over the past century. In 2008, dead coral assemblages were dominated by large, branching Acropora and living coral assemblages by genera typically found in turbid inshore environments. The timing of Acropora mortality was found to be occasionally synchronous among reefs and frequently linked to discrete disturbance events, occurring in the 1920s to 1960s and again in the 1980s to 1990s. Surveys conducted in 2014 revealed low Acropora cover (<5%) across all sites, with very little evidence of change for up to 60 y at some sites. Collectively, our results suggest a loss of resilience of this formerly dominant key framework builder at a regional scale, with recovery severely lagging behind predictions. Our study implies that the management of these reefs may be predicated on a shifted baseline.

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

NASA Astrophysics Data System (ADS)

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

2017-09-01

Hard coral cover on the Great Barrier Reef (GBR) is on a trajectory of decline. However, little is known about past coral mortality before the advent of long-term monitoring (circa 1980s). Using paleoecological analysis and high-precision uranium-thorium (U-Th) dating, we reveal an extensive loss of branching Acropora corals and changes in coral community structure in the Palm Islands region of the central GBR over the past century. In 2008, dead coral assemblages were dominated by large, branching Acropora and living coral assemblages by genera typically found in turbid inshore environments. The timing of Acropora mortality was found to be occasionally synchronous among reefs and frequently linked to discrete disturbance events, occurring in the 1920s to 1960s and again in the 1980s to 1990s. Surveys conducted in 2014 revealed low Acropora cover (<5%) across all sites, with very little evidence of change for up to 60 y at some sites. Collectively, our results suggest a loss of resilience of this formerly dominant key framework builder at a regional scale, with recovery severely lagging behind predictions. Our study implies that the management of these reefs may be predicated on a shifted baseline.

Climate-Smart Design for Ecosystem Management: A Test Application for Coral Reefs.

PubMed

West, Jordan M; Courtney, Catherine A; Hamilton, Anna T; Parker, Britt A; Julius, Susan H; Hoffman, Jennie; Koltes, Karen H; MacGowan, Petra

2017-01-01

The interactive and cumulative impacts of climate change on natural resources such as coral reefs present numerous challenges for conservation planning and management. Climate change adaptation is complex due to climate-stressor interactions across multiple spatial and temporal scales. This leaves decision makers worldwide faced with local, regional, and global-scale threats to ecosystem processes and services, occurring over time frames that require both near-term and long-term planning. Thus there is a need for structured approaches to adaptation planning that integrate existing methods for vulnerability assessment with design and evaluation of effective adaptation responses. The Corals and Climate Adaptation Planning project of the U.S. Coral Reef Task Force seeks to develop guidance for improving coral reef management through tailored application of a climate-smart approach. This approach is based on principles from a recently-published guide which provides a framework for adopting forward-looking goals, based on assessing vulnerabilities to climate change and applying a structured process to design effective adaptation strategies. Work presented in this paper includes: (1) examination of the climate-smart management cycle as it relates to coral reefs; (2) a compilation of adaptation strategies for coral reefs drawn from a comprehensive review of the literature; (3) in-depth demonstration of climate-smart design for place-based crafting of robust adaptation actions; and (4) feedback from stakeholders on the perceived usefulness of the approach. We conclude with a discussion of lessons-learned on integrating climate-smart design into real-world management planning processes and a call from stakeholders for an "adaptation design tool" that is now under development.

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.

Decadal-scale rates of reef erosion following El Niño-related mass coral mortality.

PubMed

Roff, George; Zhao, Jian-Xin; Mumby, Peter J

2015-12-01

As the frequency and intensity of coral mortality events increase under climate change, understanding how declines in coral cover may affect the bioerosion of reef frameworks is of increasing importance. Here, we explore decadal-scale rates of bioerosion of the framework building coral Orbicella annularis by grazing parrotfish following the 1997/1998 El Niño-related mass mortality event at Long Cay, Belize. Using high-precision U-Th dating and CT scan analysis, we quantified in situ rates of external bioerosion over a 13-year period (1998-2011). Based upon the error-weighted average U-Th age of dead O. annularis skeletons, we estimate the average external bioerosion between 1998 and 2011 as 0.92 ± 0.55 cm depth. Empirical observations of herbivore foraging, and a nonlinear numerical response of parrotfish to an increase in food availability, were used to create a model of external bioerosion at Long Cay. Model estimates of external bioerosion were in close agreement with U-Th estimates (0.85 ± 0.09 cm). The model was then used to quantify how rates of external bioerosion changed across a gradient of coral mortality (i.e., from few corals experiencing mortality following coral bleaching to complete mortality). Our results indicate that external bioerosion is remarkably robust to declines in coral cover, with no significant relationship predicted between the rate of external bioerosion and the proportion of O. annularis that died in the 1998 bleaching event. The outcome was robust because the reduction in grazing intensity that follows coral mortality was compensated for by a positive numerical response of parrotfish to an increase in food availability. Our model estimates further indicate that for an O. annularis-dominated reef to maintain a positive state of reef accretion, a necessity for sustained ecosystem function, live cover of O. annularis must not drop below a ~5-10% threshold of cover. © 2015 John Wiley & Sons Ltd.

Influence of Eunice norvegica on feeding and calcification in the coral Lophelia pertusa

NASA Astrophysics Data System (ADS)

Mueller, C. E.; van Oevelen, D.; Middelburg, J. J.; Lundälv, T.

2012-04-01

Lophelia pertusa is the main framework building cold-water coral in the North Atlantic. It forms complex reef structures, extending up to several km in length and several meters in hight. Many species are attracted by the coral frame work, forming a highly diverse community within the reef. Although most work has focused on the corals, the functioning of the system also depends on interactions between corals and associated species. A particular example is the Polychaete Eunice norvegica that lives in close association with the coral host. The Polychaete builds a thin texture-tube between living coral branches and stimulates the coral to calcify the tube. This process strengthens the reef framwork by thickening and connecting coral brances and thereby acts as a positive feedback on the development of large reef structures. This comes however at an metabolic cost for the coral due to the enhanced calcificationrates. Another negative feedback for cold-water coral may be food related, since aquaria observations have shown that Eunice occasionally steels food from its host coral. In this study we investigated the interactions between the coral and polychaete related to calcification and food partitioning for two food types (algae and Artemia). The uptake of 13C and 15N labeled food sources by the worm and the coral was studied in chambers with only corals, only the polychaete and both species present. After 7 days, corals and worms were analyzed for isotope incorporation in bulk tissue and skeleton samples and specific fatty acids (13C) using GC-c-IRMS (gas-chromatography-combustion-isotope ratio mass spectrometry). Corals that were kept in the presence of Eunice indeed showed a higher calcification rates of 7.4 ug C (day* g dw coral)-1, evidencing the stimulation of calcification by Eunice. Interestingly, food uptake of algae and Artemia was higher in the coral-worm treatment for both species as compared to the single species treatments. These results shed new light on trophic and non-trophic interactions in cold-water coral reefs.

A unified framework for modelling sediment fate from source to sink and its interactions with reef systems over geological times.

PubMed

Salles, Tristan; Ding, Xuesong; Webster, Jody M; Vila-Concejo, Ana; Brocard, Gilles; Pall, Jodie

2018-03-27

Understanding the effects of climatic variability on sediment dynamics is hindered by limited ability of current models to simulate long-term evolution of sediment transfer from source to sink and associated morphological changes. We present a new approach based on a reduced-complexity model which computes over geological time: sediment transport from landmasses to coasts, reworking of marine sediments by longshore currents, and development of coral reef systems. Our framework links together the main sedimentary processes driving mixed siliciclastic-carbonate system dynamics. It offers a methodology for objective and quantitative sediment fate estimations over regional and millennial time-scales. A simulation of the Holocene evolution of the Great Barrier Reef shows: (1) how high sediment loads from catchments erosion prevented coral growth during the early transgression phase and favoured sediment gravity-flows in the deepest parts of the northern region basin floor (prior to 8 ka before present (BP)); (2) how the fine balance between climate, sea-level, and margin physiography enabled coral reefs to thrive under limited shelf sedimentation rates after ~6 ka BP; and, (3) how since 3 ka BP, with the decrease of accommodation space, reduced of vertical growth led to the lateral extension of reefs consistent with available observational data.

Resilience in carbonate production despite three coral bleaching events in 5 years on an inshore patch reef in the Florida Keys.

PubMed

Manzello, Derek P; Enochs, Ian C; Kolodziej, Graham; Carlton, Renée; Valentino, Lauren

2018-01-01

The persistence of coral reef frameworks requires that calcium carbonate (CaCO 3 ) production by corals and other calcifiers outpaces CaCO 3 loss via physical, chemical, and biological erosion. Coral bleaching causes declines in CaCO 3 production, but this varies with bleaching severity and the species impacted. We conducted census-based CaCO 3 budget surveys using the established ReefBudget approach at Cheeca Rocks, an inshore patch reef in the Florida Keys, annually from 2012 to 2016. This site experienced warm-water bleaching in 2011, 2014, and 2015. In 2017, we obtained cores of the dominant calcifying coral at this site, Orbicella faveolata , to understand how calcification rates were impacted by bleaching and how they affected the reef-wide CaCO 3 budget. Bleaching depressed O. faveolata growth and the decline of this one species led to an overestimation of mean (± std. error) reef-wide CaCO 3 production by + 0.68 (± 0.167) to + 1.11 (± 0.236) kg m -2  year -1 when using the static ReefBudget coral growth inputs. During non-bleaching years, the ReefBudget inputs slightly underestimated gross production by - 0.10 (± 0.022) to - 0.43 (± 0.100) kg m -2  year -1 . Carbonate production declined after the first year of back-to-back bleaching in 2014, but then increased after 2015 to values greater than the initial surveys in 2012. Cheeca Rocks is an outlier in the Caribbean and Florida Keys in terms of coral cover, carbonate production, and abundance of O. faveolata , which is threatened under the Endangered Species Act. Given the resilience of this site to repeated bleaching events, it may deserve special management attention.

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

PubMed

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

2014-10-01

Coral reef fishes are exploited without the knowledge of their sustainability and their possible effect in altering the community structure of a coral reef ecosystem. Alteration of the community structure could cause a decline in the health of coral reefs and its services. We documented the coral community structure, status of live corals and reef fish assemblages in Palk Bay at the reef fishing hotspots and its nearby reef area with minimum fishing pressure and compared it with a control reef area where reef fishing was banned for more than two decades. The comparison was based on the percent cover of different forms of live corals, their diversity and the density and diversity of reef fishes. The reef fish stock in the reef fishing hotspots and its neighbouring reef was lower by 61 and 38%, respectively compared to the control reef. The herbivore fish Scarus ghobban and Siganus javus were exploited at a rate of 250 and 105 kg month(-1) fishermen(-1), respectively, relatively high comparing the small reef area. Live and dead corals colonized by turf algae were predominant in both the reef fishing hotspots and its nearby coral ecosystems. The percent cover of healthy live corals and live corals colonized by turf algae was <10 and >80%, respectively, in the intensively fished coral ecosystems. The corals were less diverse and the massive Porites and Favia colonies were abundant in the intensive reef fishing sites. Results of this study suggest that the impact of reef fish exploitation was not solely restricted to the intensively fished reefs, but also to the nearby reefs which play a critical role in the resilience of degraded reef ecosystems.

Ten years after the crime: Lasting effects of damage from a cruise ship anchor on a coral reef in St. John, U.S. Virgin Islands

USGS Publications Warehouse

Rogers, C.S.; Garrison, V.H.

2001-01-01

In October 1988, a cruise ship dropped its anchor on a coral reef in Virgin Islands National Park, St. John, creating a distinct scar roughly 128 m long and 3 m wide from a depth of 22 m to a depth of 6 m. The anchor pulverized coral colonies and smashed part of the reef framework. In April 1991, nine permanent quadrats (1 m2) were established inside the scar over a depth range of 9 m to 12.5 m. At that time, average coral cover inside the scar was less than 1%. These quadrats were surveyed again in 1992, 1993, 1994, 1995 and 1998. Recruits of 19 coral species have been observed, with Agaricia agaricites and Porites spp. the most abundant. Quadrats surveyed outside the scar in June 1994 over the same depth range had a higher percent coral cover (mean = 7.4%, SD = 4.5) and greater average size (maximum length) of coral colonies than in quadrats inside the damaged area. Although coral recruits settle into the scar in high densities, live coral cover has not increased significantly in the last 10 yrs, reflecting poor survival and growth of newly settled corals. The relatively planar aspect of the scar may increase the vulnerability of the recruits to abrasion and mortality from shifting sediments. Ten years after the anchor damage occurred, live coral cover in the still-visible scar (mean = 2.6%, SD = 2.7) remains well below the cover found in the adjacent, undamaged reef.

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 study identified bottlenecks to recovery of coral assemblages that varied depending on post-disturbance habitat condition.

Global warming transforms coral reef assemblages.

PubMed

Hughes, Terry P; Kerry, James T; Baird, Andrew H; Connolly, Sean R; Dietzel, Andreas; Eakin, C Mark; Heron, Scott F; Hoey, Andrew S; Hoogenboom, Mia O; Liu, Gang; McWilliam, Michael J; Pears, Rachel J; Pratchett, Morgan S; Skirving, William J; Stella, Jessica S; Torda, Gergely

2018-04-01

Global warming is rapidly emerging as a universal threat to ecological integrity and function, highlighting the urgent need for a better understanding of the impact of heat exposure on the resilience of ecosystems and the people who depend on them 1 . Here we show that in the aftermath of the record-breaking marine heatwave on the Great Barrier Reef in 2016 2 , corals began to die immediately on reefs where the accumulated heat exposure exceeded a critical threshold of degree heating weeks, which was 3-4 °C-weeks. After eight months, an exposure of 6 °C-weeks or more drove an unprecedented, regional-scale shift in the composition of coral assemblages, reflecting markedly divergent responses to heat stress by different taxa. Fast-growing staghorn and tabular corals suffered a catastrophic die-off, transforming the three-dimensionality and ecological functioning of 29% of the 3,863 reefs comprising the world's largest coral reef system. Our study bridges the gap between the theory and practice of assessing the risk of ecosystem collapse, under the emerging framework for the International Union for Conservation of Nature (IUCN) Red List of Ecosystems 3 , by rigorously defining both the initial and collapsed states, identifying the major driver of change, and establishing quantitative collapse thresholds. The increasing prevalence of post-bleaching mass mortality of corals represents a radical shift in the disturbance regimes of tropical reefs, both adding to and far exceeding the influence of recurrent cyclones and other local pulse events, presenting a fundamental challenge to the long-term future of these iconic ecosystems.

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

ERIC Educational Resources Information Center

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

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

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

NASA Astrophysics Data System (ADS)

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

2017-05-01

Coral reefs in the Xisha Islands (also known as the Paracel Islands in English), South China Sea, have experienced dramatic declines in coral cover. However, the current regional scale hard coral distribution of geomorphic and ecological zones, essential for reefs management in the context of global warming and ocean acidification, is not well documented. We analyzed data from field surveys, Landsat-8 and GF-1 images to map the distribution of hard coral within geomorphic zones and reef flat ecological zones. In situ surveys conducted in June 2014 on nine reefs provided a complete picture of reef status with regard to live coral diversity, evenness of coral cover and reef health (live versus dead cover) for the Xisha Islands. Mean coral cover was 12.5% in 2014 and damaged reefs seemed to show signs of recovery. Coral cover in sheltered habitats such as lagoon patch reefs and biotic dense zones of reef flats was higher, but there were large regional differences and low diversity. In contrast, the more exposed reef slopes had high coral diversity, along with high and more equal distributions of coral cover. Mean hard coral cover of other zones was <10%. The total Xisha reef system was estimated to cover 1 060 km2, and the emergent reefs covered 787 m2. Hard corals of emergent reefs were considered to cover 97 km2. The biotic dense zone of the reef flat was a very common zone on all simple atolls, especially the broader northern reef flats. The total cover of live and dead coral can reach above 70% in this zone, showing an equilibrium between live and dead coral as opposed to coral and algae. This information regarding the spatial distribution of hard coral can support and inform the management of Xisha reef ecosystems.

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

ERIC Educational Resources Information Center

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

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

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.

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 that some coral species are crucial in maintaining the structural diversity of coral reefs.

Reef Development on Artificial Patch Reefs in Shallow Water of Panjang Island, Central Java

NASA Astrophysics Data System (ADS)

Munasik; Sugiyanto; Sugianto, Denny N.; Sabdono, Agus

2018-02-01

Reef restoration methods are generally developed by propagation of coral fragments, coral recruits and provide substrate for coral attachment using artificial reefs (ARs). ARs have been widely applied as a tool for reef restoration in degraded natural reefs. Successful of coral restoration is determined by reef development such as increasing coral biomass, natural of coral recruits and fauna associated. Artificial Patch Reefs (APRs) is designed by combined of artificial reefs and coral transplantation and constructed by modular circular structures in shape, were deployed from small boats by scuba divers, and are suitable near natural reefs for shallow water with low visibility of Panjang Island, Central Java. Branching corals of Acropora aspera, Montipora digitata and Porites cylindrica fragments were transplanted on to each module of two units of artificial patch reefs in different periods. Coral fragments of Acropora evolved high survival and high growth, Porites fragments have moderate survival and low growth, while fragment of Montipora show in low survival and moderate growth. Within 19 to 22 months of APRs deployment, scleractinian corals were recruited on the surface of artificial patch reef substrates. The most recruits abundant was Montastrea, followed by Poritids, Pocilloporids, and Acroporids. We conclude that artificial patch reefs with developed by coral fragments and natural coral recruitment is one of an alternative rehabilitation method in shallow reef with low visibility.

75 FR 48934 - Coral Reef Conservation Program Implementation Guidelines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-12

...-01] RIN 0648-ZC19 Coral Reef Conservation Program Implementation Guidelines AGENCY: National Oceanic... Guidelines (Guidelines) for the Coral Reef Conservation Program (CRCP or Program) under the Coral Reef... assistance for coral reef conservation projects under the Act. NOAA revised the Implementation Guidelines for...

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

PubMed

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

2013-09-01

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

Linking Demographic Processes of Juvenile Corals to Benthic Recovery Trajectories in Two Common Reef Habitats

PubMed Central

Doropoulos, Christopher; Ward, Selina; Roff, George; González-Rivero, Manuel; Mumby, Peter J.

2015-01-01

Tropical reefs are dynamic ecosystems that host diverse coral assemblages with different life-history strategies. Here, we quantified how juvenile (<50 mm) coral demographics influenced benthic coral structure in reef flat and reef slope habitats on the southern Great Barrier Reef, Australia. Permanent plots and settlement tiles were monitored every six months for three years in each habitat. These environments exhibited profound differences: the reef slope was characterised by 95% less macroalgal cover, and twice the amount of available settlement substrata and rates of coral settlement than the reef flat. Consequently, post-settlement coral survival in the reef slope was substantially higher than that of the reef flat, and resulted in a rapid increase in coral cover from 7 to 31% in 2.5 years. In contrast, coral cover on the reef flat remained low (~10%), whereas macroalgal cover increased from 23 to 45%. A positive stock-recruitment relationship was found in brooding corals in both habitats; however, brooding corals were not directly responsible for the observed changes in coral cover. Rather, the rapid increase on the reef slope resulted from high abundances of broadcast spawning Acropora recruits. Incorporating our results into transition matrix models demonstrated that most corals escape mortality once they exceed 50 mm, but for smaller corals mortality in brooders was double those of spawners (i.e. acroporids and massive corals). For corals on the reef flat, sensitivity analysis demonstrated that growth and mortality of larger juveniles (21–50 mm) highly influenced population dynamics; whereas the recruitment, growth and mortality of smaller corals (<20 mm) had the highest influence on reef slope population dynamics. Our results provide insight into the population dynamics and recovery trajectories in disparate reef habitats, and highlight the importance of acroporid recruitment in driving rapid increases in coral cover following large-scale perturbation in reef slope environments. PMID:26009892

Linking demographic processes of juvenile corals to benthic recovery trajectories in two common reef habitats.

PubMed

Doropoulos, Christopher; Ward, Selina; Roff, George; González-Rivero, Manuel; Mumby, Peter J

2015-01-01

Tropical reefs are dynamic ecosystems that host diverse coral assemblages with different life-history strategies. Here, we quantified how juvenile (<50 mm) coral demographics influenced benthic coral structure in reef flat and reef slope habitats on the southern Great Barrier Reef, Australia. Permanent plots and settlement tiles were monitored every six months for three years in each habitat. These environments exhibited profound differences: the reef slope was characterised by 95% less macroalgal cover, and twice the amount of available settlement substrata and rates of coral settlement than the reef flat. Consequently, post-settlement coral survival in the reef slope was substantially higher than that of the reef flat, and resulted in a rapid increase in coral cover from 7 to 31% in 2.5 years. In contrast, coral cover on the reef flat remained low (~10%), whereas macroalgal cover increased from 23 to 45%. A positive stock-recruitment relationship was found in brooding corals in both habitats; however, brooding corals were not directly responsible for the observed changes in coral cover. Rather, the rapid increase on the reef slope resulted from high abundances of broadcast spawning Acropora recruits. Incorporating our results into transition matrix models demonstrated that most corals escape mortality once they exceed 50 mm, but for smaller corals mortality in brooders was double those of spawners (i.e. acroporids and massive corals). For corals on the reef flat, sensitivity analysis demonstrated that growth and mortality of larger juveniles (21-50 mm) highly influenced population dynamics; whereas the recruitment, growth and mortality of smaller corals (<20 mm) had the highest influence on reef slope population dynamics. Our results provide insight into the population dynamics and recovery trajectories in disparate reef habitats, and highlight the importance of acroporid recruitment in driving rapid increases in coral cover following large-scale perturbation in reef slope environments.

78 FR 66683 - Fisheries in the Western Pacific; Special Coral Reef Ecosystem Fishing Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-06

... the Western Pacific; Special Coral Reef Ecosystem Fishing Permit AGENCY: National Marine Fisheries... special coral reef ecosystem fishing permit. SUMMARY: NMFS issued a Special Coral Reef Ecosystem Fishing Permit that authorizes Kampachi Farms, LLC, to culture and harvest a coral reef ecosystem management unit...

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 influence of sea level and cyclones on Holocene reef flat development: Middle Island, central Great Barrier Reef

NASA Astrophysics Data System (ADS)

Ryan, E. J.; Smithers, S. G.; Lewis, S. E.; Clark, T. R.; Zhao, J. X.

2016-09-01

The geomorphology and chronostratigraphy of the reef flat (including microatoll ages and elevations) were investigated to better understand the long-term development of the reef at Middle Island, inshore central Great Barrier Reef. Eleven cores across the fringing reef captured reef initiation, framework accretion and matrix sediments, allowing a comprehensive appreciation of reef development. Precise uranium-thorium ages obtained from coral skeletons revealed that the reef initiated ~7873 ± 17 years before present (yBP), and most of the reef was emplaced in the following 1000 yr. Average rates of vertical reef accretion ranged between 3.5 and 7.6 mm yr-1. Reef framework was dominated by branching corals ( Acropora and Montipora). An age hiatus of ~5000 yr between 6439 ± 19 and 1617 ± 10 yBP was observed in the core data and attributed to stripping of the reef structure by intense cyclones during the mid- to late-Holocene. Large shingle ridges deposited onshore and basset edges preserved on the reef flat document the influence of cyclones at Middle Island and represent potential sinks for much of the stripped material. Stripping of the upper reef structure around the outer margin of the reef flat by cyclones created accommodation space for a thin (<1.2 m) veneer of reef growth after 1617 ± 10 yBP that grew over the eroded mid-Holocene reef structure. Although limited fetch and open-water exposure might suggest the reef flat at Middle Island is quite protected, our results show that high-energy waves presumably generated by cyclones have significantly influenced both Holocene reef growth and contemporary reef flat geomorphology.

The big squeeze: ecosystem change and contraction of habitat for newly discovered deep-water reefs off the U.S. West Coast

NASA Astrophysics Data System (ADS)

Wickes, L.; Etnoyer, P. J.; Lauermann, A.; Rosen, D.

2016-02-01

Cold-water reefs are fragile, complex ecosystems that extend into the bathyal depths of the ocean, creating three dimensional structure and habitat for a diversity of deep-water invertebrates and fishes. The cold waters of the California Current support a diverse assemblage of these corals at relatively shallow depths close to shore. At these depths and locations the communities face a multitude of stressors, including low carbonate saturations, hypoxia, changing temperature, and coastal pollution. The current study employed ROV surveys (n=588, 2003-2015) to document the distribution of deep-sea corals in the Southern California Bight, including the first description of a widespread reef-building coral in the naturally acidified waters off the U.S. West Coast. We provide empirical evidence of species survival in the corrosive waters (Ωarag 0.67-1.86), but find loss of reef integrity. Recent publications have implied acclimation, resistance, and resilience of cold-water reef-building corals to ocean acidification, but results of this study indicate a cost to skeletal framework development with a subsequent loss of coral habitat. While ocean acidification and declines in oxygen are expected to further impinge on Lophelia at depth (𝑥̅=190 m), surface warming and coastal polution may affect shallower populations and mesophotic reef assemblages, resulting in a contraction of available coral habitat. Recent observations of die offs of gorgonians and antipatharians from surveys in shallow (50 m) and deep water (500 m) provide compelling evidence of ongoing ecosystem changes. Concurrent losses in habitat quality in deep and mesophotic waters suggest that corals may be "squeezed" into a more restricted depth range. New monitoring efforts aim to characterize the health and condition of deep corals with respect to gradients in carbonate chemistry, coastal pollution and changing temperatures, to assess vulnerability and both current and future habitat suitability.

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

PubMed

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

2014-08-22

Coral reefs are in global decline, converting from dominance by coral to dominance by seaweed. Once seaweeds become abundant, coral recovery is suppressed unless herbivores return to remove seaweeds, and corals then recruit. Variance in the recovery of fishes and corals is not well understood. We show that juveniles of both corals and fishes are repelled by chemical cues from fished, seaweed-dominated reefs but attracted to cues from coral-dominated areas where fishing is prohibited. Chemical cues of specific seaweeds from degraded reefs repulsed recruits, and cues from specific corals that are typical of healthy reefs attracted recruits. Juveniles were present at but behaviorally avoided recruiting to degraded reefs dominated by seaweeds. For recovery, degraded reefs may need to be managed to produce cues that attract, rather than repel, recruiting corals and fishes. Copyright © 2014, American Association for the Advancement of Science.

Impact of sea-level rise and coral mortality on the wave dynamics and wave forces on barrier reefs.

PubMed

Baldock, T E; Golshani, A; Callaghan, D P; Saunders, M I; Mumby, P J

2014-06-15

A one-dimensional wave model was used to investigate the reef top wave dynamics across a large suite of idealized reef-lagoon profiles, representing barrier coral reef systems under different sea-level rise (SLR) scenarios. The modeling shows that the impacts of SLR vary spatially and are strongly influenced by the bathymetry of the reef and coral type. A complex response occurs for the wave orbital velocity and forces on corals, such that the changes in the wave dynamics vary reef by reef. Different wave loading regimes on massive and branching corals also leads to contrasting impacts from SLR. For many reef bathymetries, wave orbital velocities increase with SLR and cyclonic wave forces are reduced for certain coral species. These changes may be beneficial to coral health and colony resilience and imply that predicting SLR impacts on coral reefs requires careful consideration of the reef bathymetry and the mix of coral species. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

Miyazaki, Tadakuni; Harashima, Akira; Nakatani, Yukihiro

Coral reefs are the major sites for photo-synthesis and calcification in the present ocean. Estimating the production rate of calcification by the coral reefs or investigating the sink/source mechanism of CO{sub 2} by the coral reefs in the ocean, the distribution of the coral reefs in the world wide must be identified. Measuring the spectral signatures of underwater coral reefs and mapping of coral reefs by satellite remote sensing are described. The spectral signatures of different species of the coral reefs were measured using a spectroradiometer at off Kuroshima Island, Okinawa, Japan and investigated spectral difference between different species ofmore » the coral reefs. As well as the field experiments, laboratory experiments for measuring the spectral signatures of 9 different species of coral reefs were carried out with the same spectroradiometer. The spectral reflectance of each coral reef showed a significant result that a narrow absorption band exists in the spectral region between 660 and 680 nm, and very strong spectral reflectance from about 700 nm towards the longer wavelength range. On the other hand, absorption and the high reflectance region were not observed from the bottom sands or bare rocks underwater. These experiments suggested that there is a significant spectral difference between coral reefs and bottom sands or bare rocks and so the best spectral range for separating the coral reefs from other underwater objects in the ocean would be between 700 and 800 nm. As well as the basic spectral measurement either in the field or at the laboratory, SPOT satellite imageries were used to classify the underwater coral reefs. Classification methods used here were the principal component analysis, and the maximum likelihood. Finally, the evaluation of classification method for extracting the coral reefs was introduced.« less

Coral identity underpins architectural complexity on Caribbean reefs.

PubMed

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

2011-09-01

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

Historical baselines of coral cover on tropical reefs as estimated by expert opinion

PubMed Central

Cheung, William W.L.; Bruno, John F.

2018-01-01

Coral reefs are important habitats that represent global marine biodiversity hotspots and provide important benefits to people in many tropical regions. However, coral reefs are becoming increasingly threatened by climate change, overfishing, habitat destruction, and pollution. Historical baselines of coral cover are important to understand how much coral cover has been lost, e.g., to avoid the ‘shifting baseline syndrome’. There are few quantitative observations of coral reef cover prior to the industrial revolution, and therefore baselines of coral reef cover are difficult to estimate. Here, we use expert and ocean-user opinion surveys to estimate baselines of global coral reef cover. The overall mean estimated baseline coral cover was 59% (±19% standard deviation), compared to an average of 58% (±18% standard deviation) estimated by professional scientists. We did not find evidence of the shifting baseline syndrome, whereby respondents who first observed coral reefs more recently report lower estimates of baseline coral cover. These estimates of historical coral reef baseline cover are important for scientists, policy makers, and managers to understand the extent to which coral reefs have become depleted and to set appropriate recovery targets. PMID:29379692

Historical baselines of coral cover on tropical reefs as estimated by expert opinion.

PubMed

Eddy, Tyler D; Cheung, William W L; Bruno, John F

2018-01-01

Coral reefs are important habitats that represent global marine biodiversity hotspots and provide important benefits to people in many tropical regions. However, coral reefs are becoming increasingly threatened by climate change, overfishing, habitat destruction, and pollution. Historical baselines of coral cover are important to understand how much coral cover has been lost, e.g., to avoid the 'shifting baseline syndrome'. There are few quantitative observations of coral reef cover prior to the industrial revolution, and therefore baselines of coral reef cover are difficult to estimate. Here, we use expert and ocean-user opinion surveys to estimate baselines of global coral reef cover. The overall mean estimated baseline coral cover was 59% (±19% standard deviation), compared to an average of 58% (±18% standard deviation) estimated by professional scientists. We did not find evidence of the shifting baseline syndrome, whereby respondents who first observed coral reefs more recently report lower estimates of baseline coral cover. These estimates of historical coral reef baseline cover are important for scientists, policy makers, and managers to understand the extent to which coral reefs have become depleted and to set appropriate recovery targets.

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

EPA Science Inventory

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

Measuring, interpreting, and responding to changes in coral reefs: A challenge for biologists, geologist, and managers

USGS Publications Warehouse

Rogers, Caroline S.; Miller, Jeff; Hubbard, Dennis K.; Rogers, Caroline S.; Lipps, Jere H.; Stanley, George D.

2016-01-01

What, exactly, is a coral reef? And how have the world’s reefs changed in the last several decades? What are the stressors undermining reef structure and function? Given the predicted effects of climate change, do reefs have a future? Is it possible to “manage” coral reefs for resilience? What can coral reef scientists contribute to improve protection and management of coral reefs? What insights can biologists and geologists provide regarding the persistence of coral reefs on a human timescale? What is reef change to a biologist… to a geologist?Clearly, there are many challenging questions. In this chapter, we present some of our thoughts on monitoring and management of coral reefs in US national parks in the Caribbean and western Atlantic based on our experience as members of monitoring teams. We reflect on the need to characterize and evaluate reefs, on how to conduct high-quality monitoring programs, and on what we can learn from biological and geological experiments and investigations. We explore the possibility that specific steps can be taken to “manage” coral reefs for greater resilience.

Dynamic regulation of partner abundance mediates response of reef coral symbioses to environmental change.

PubMed

Cunning, R; Vaughan, N; Gillette, P; Capo, T R; Matté, J L; Baker, A C

2015-05-01

Regulating partner abunclance may allow symmotic organisms to mediate interaction outcomes, facilitating adaptive responses to environmental change. To explore the capacity for-adaptive regulation in an ecologically important endosymbiosis, we studied the population dynamics of symbiotic algae in reef-building corals under different abiotic contexts. We found high natural variability in symbiont abundance in corals across reefs, but this variability converged to different symbiont-specific abundances when colonies were maintained under constant conditions. When conditions changed seasonally, symbiont abundance readjusted to new equilibria. We explain these patterns using an a priori model of symbiotic costs and benefits to the coral host, which shows that the observed changes in symbiont abundance are consistent with the maximization of interaction benefit under different environmental conditions. These results indicate that, while regulating symbiont abundance helps hosts sustain maximum benefit in a dynamic environment, spatiotemporal variation in abiotic factors creates a broad range of symbiont abundances (and interaction outcomes) among corals that may account for observed natural variability in performance (e.g., growth rate) and stress tolerance (e.g., bleaching susceptibility). This cost or benefit framework provides a new perspective on the dynamic regulation of reef coral symbioses and illustrates that the dependence of interaction outcomes on biotic and abiotic contexts may be important in understanding how diverse mutualisms respond to environmental change.

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

PubMed

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

2013-12-12

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

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 vulnerability of the Palk Bay reef to species-specific endemic threats.

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

Using coral disease prevalence to assess the effects of concentrating tourism activities on offshore reefs in a tropical marine park.

PubMed

Lamb, Joleah B; Willis, Bette L

2011-10-01

Concentrating tourism activities can be an effective way to closely manage high-use parks and minimize the extent of the effects of visitors on plants and animals, although considerable investment in permanent tourism facilities may be required. On coral reefs, a variety of human-related disturbances have been associated with elevated levels of coral disease, but the effects of reef-based tourist facilities (e.g., permanent offshore visitor platforms) on coral health have not been assessed. In partnership with reef managers and the tourism industry, we tested the effectiveness of concentrating tourism activities as a strategy for managing tourism on coral reefs. We compared prevalence of brown band disease, white syndromes, black band disease, skeletal eroding band, and growth anomalies among reefs with and without permanent tourism platforms within the Great Barrier Reef Marine Park. Coral diseases were 15 times more prevalent at reefs with offshore tourism platforms than at nearby reefs without platforms. The maximum prevalence and maximum number of cases of each disease type were recorded at reefs with permanently moored tourism platforms. Diseases affected 10 coral genera from 7 families at reefs with platforms and 4 coral genera from 3 families at reefs without platforms. The greatest number of disease cases occurred within the spatially dominant acroporid corals, which exhibited 18-fold greater disease prevalence at reefs with platforms than at reefs without platforms. Neither the percent cover of acroporids nor overall coral cover differed significantly between reefs with and without platforms, which suggests that neither factor was responsible for the elevated levels of disease. Identifying how tourism activities and platforms facilitate coral disease in marine parks will help ensure ongoing conservation of coral assemblages and tourism. ©2011 Society for Conservation Biology.

Pattern and intensity of human impact on coral reefs depend on depth along the reef profile and on the descriptor adopted

NASA Astrophysics Data System (ADS)

Nepote, Ettore; Bianchi, Carlo Nike; Chiantore, Mariachiara; Morri, Carla; Montefalcone, Monica

2016-09-01

Coral reefs are threatened by multiple global and local disturbances. The Maldives, already heavily hit by the 1998 mass bleaching event, are currently affected also by growing tourism and coastal development that may add to global impacts. Most of the studies investigating effects of local disturbances on coral reefs assessed the response of communities along a horizontal distance from the impact source. This study investigated the status of a Maldivian coral reef around an island where an international touristic airport has been recently (2009-2011) built, at different depths along the reef profile (5-20 m depth) and considering the change in the percentage of cover of five different non-taxonomic descriptors assessed through underwater visual surveys: hard corals, soft corals, other invertebrates, macroalgae and abiotic attributes. Eight reefs in areas not affected by any coastal development were used as controls and showed a reduction of hard coral cover and an increase of abiotic attributes (i.e. sand, rock, coral rubble) at the impacted reef. However, hard coral cover, the most widely used descriptor of coral reef health, was not sufficient on its own to detect subtle indirect effects that occurred down the reef profile. Selecting an array of descriptors and considering different depths, where corals may find a refuge from climate impacts, could guide the efforts of minimising local human pressures on coral reefs.

Monitoring the impacts of Ocean Acidification on coral reef bioerosion: challenges, methods, recommendations

NASA Astrophysics Data System (ADS)

Enochs, I.; Manzello, D.; Carlton, R.

2013-05-01

Coral reef habitats exist as a dynamic balance between the additive process of calcification and the destructive effects of erosion. A disruption to either the positive or negative side of the coral reef carbonate budget can push a reef system towards rapid collapse. It is well understood that Ocean Acidification (OA) may impair calcification and emerging experimental evidence suggests that it will likely increase the erosive potential of a diverse suite of bioeroding taxa. This may lead to previously unforeseen scenarios where reef framework degradation occurs at a faster pace than that predicted by more simplistic models, resulting from the multifaceted impacts of both slower coral growth and enhanced rates of habitat erosion. As such, it is of paramount importance that monitoring plans tasked with assessing reef resilience to climate change and OA incorporate methods for quantifying bioerosion. This is a complex undertaking as reef ecosystem bioerosion is the result of numerous behaviors, employed by diverse flora and fauna, operating at vastly different scales. Furthermore, these erosive processes are highly variable, dependent on seasonal fluctuations and differing between reef regions, species, individuals, and even the physical characteristics of the substrates acted upon. The strengths and weaknesses of existing bioerosion monitoring methodologies are discussed, ranging from quantification of single species erosion rates to multi-phyletic census-based approaches. Traditional techniques involving the weight change of carbonate blocks are compared alongside more modern methodologies such as micro computed tomography. Finally, recommendations are made for a comprehensive monitoring strategy, incorporating multiple methodologies in a time and cost-effective manner.

A Decision Support Framework For Science-Based, Multi-Stakeholder Deliberation: A Coral Reef Example

EPA Science Inventory

We present a decision support framework for science-based assessment and multi-stakeholder deliberation. The framework consists of two parts: a DPSIR (Drivers-Pressures-States-Impacts-Responses) analysis to identify the important causal relationships among anthropogenic environ...

Chemically mediated behavior of recruiting corals and fishes: A tipping point that may limit reef recovery

PubMed Central

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

2015-01-01

Coral reefs are in global decline, converting from dominance by coral to dominance by seaweed. Once seaweeds become abundant, coral recovery is suppressed unless herbivores return to remove seaweeds, and corals then recruit. Variance in the recovery of fishes and corals is not well understood. We show that juveniles of both corals and fishes are repelled by chemical cues from fished, seaweed-dominated reefs but attracted to cues from coral-dominated areas where fishing is prohibited. Chemical cues of specific seaweeds from degraded reefs repulsed recruits, and cues from specific corals that are typical of healthy reefs attracted recruits. Juveniles were present at but behaviorally avoided recruiting to degraded reefs dominated by seaweeds. For recovery, degraded reefs may need to be managed to produce cues that attract, rather than repel, recruiting corals and fishes. PMID:25146281

Harnessing Natural Recovery Processes to Improve Restoration Outcomes: An Experimental Assessment of Sponge-Mediated Coral Reef Restoration

PubMed Central

Biggs, Brendan C.

2013-01-01

Background Restoration is increasingly implemented to reestablish habitat structure and function following physical anthropogenic disturbance, but scientific knowledge of effectiveness of methods lags behind demand for guidelines. On coral reefs, recovery is largely dependent on coral reestablishment, and substratum stability is critical to the survival of coral fragments and recruits. Concrete is often used to immobilize rubble, but its ecological performance has not been rigorously evaluated, and restoration has generally fallen short of returning degraded habitat to pre-disturbance conditions. Fragments of erect branching sponges mediate reef recovery by facilitating rubble consolidation, yet such natural processes have been largely overlooked in restoring reefs. Methods On two reefs in Curacao, four treatments - coral rubble alone, rubble seeded with sponge fragments, rubble bound by concrete, and concrete “rubble” bound by concrete - were monitored over four years to investigate rubble consolidation with and without sponges and the ecological performance of treatments in terms of the number and diversity of coral recruits. Species specific rates of sponge fragment attachment to rubble, donor sponge growth and tissue replacement, and fragment survival inside rubble piles were also investigated to evaluate sponge species performance and determine rates for sustainably harvesting tissue. Findings/Significance Rubble piles seeded with sponges retained height and shape to a significantly greater degree, lost fewer replicates to water motion, and were significantly more likely to be consolidated over time than rubble alone. Significantly more corals recruited to sponge-seeded rubble than to all other treatments. Coral diversity was also greatest for rubble with sponges and it was the only treatment to which framework building corals recruited. Differences in overall sponge species performance suggest species selection is important to consider. Employing organisms that jump start successional pathways and facilitate recovery can significantly improve restoration outcomes; however, best practices require techniques be tailored to each system. PMID:23750219

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

Individual-based analyses reveal limited functional overlap in a coral reef fish community.

PubMed

Brandl, Simon J; Bellwood, David R

2014-05-01

Detailed knowledge of a species' functional niche is crucial for the study of ecological communities and processes. The extent of niche overlap, functional redundancy and functional complementarity is of particular importance if we are to understand ecosystem processes and their vulnerability to disturbances. Coral reefs are among the most threatened marine systems, and anthropogenic activity is changing the functional composition of reefs. The loss of herbivorous fishes is particularly concerning as the removal of algae is crucial for the growth and survival of corals. Yet, the foraging patterns of the various herbivorous fish species are poorly understood. Using a multidimensional framework, we present novel individual-based analyses of species' realized functional niches, which we apply to a herbivorous coral reef fish community. In calculating niche volumes for 21 species, based on their microhabitat utilization patterns during foraging, and computing functional overlaps, we provide a measurement of functional redundancy or complementarity. Complementarity is the inverse of redundancy and is defined as less than 50% overlap in niche volumes. The analyses reveal extensive complementarity with an average functional overlap of just 15.2%. Furthermore, the analyses divide herbivorous reef fishes into two broad groups. The first group (predominantly surgeonfishes and parrotfishes) comprises species feeding on exposed surfaces and predominantly open reef matrix or sandy substrata, resulting in small niche volumes and extensive complementarity. In contrast, the second group consists of species (predominantly rabbitfishes) that feed over a wider range of microhabitats, penetrating the reef matrix to exploit concealed surfaces of various substratum types. These species show high variation among individuals, leading to large niche volumes, more overlap and less complementarity. These results may have crucial consequences for our understanding of herbivorous processes on coral reefs, as algal removal appears to depend strongly on species-specific microhabitat utilization patterns of herbivores. Furthermore, the results emphasize the capacity of the individual-based analyses to reveal variation in the functional niches of species, even in high-diversity systems such as coral reefs, demonstrating its potential applicability to other high-diversity ecosystems. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Mesopredator trophodynamics on thermally stressed coral reefs

NASA Astrophysics Data System (ADS)

Hempson, Tessa N.; Graham, Nicholas A. J.; MacNeil, M. Aaron; Hoey, Andrew S.; Almany, Glenn R.

2018-03-01

Ecosystems are becoming vastly modified through disturbance. In coral reef ecosystems, the differential susceptibility of coral taxa to climate-driven bleaching is predicted to shift coral assemblages towards reefs with an increased relative abundance of taxa with high thermal tolerance. Many thermally tolerant coral species are characterised by low structural complexity, with reduced habitat niche space for the small-bodied coral reef fishes on which piscivorous mesopredators feed. This study used a patch reef array to investigate the potential impacts of climate-driven shifts in coral assemblages on the trophodynamics of reef mesopredators and their prey communities. The `tolerant' reef treatment consisted only of coral taxa of low susceptibility to bleaching, while `vulnerable' reefs included species of moderate to high thermal vulnerability. `Vulnerable' reefs had higher structural complexity, and the fish assemblages that established on these reefs over 18 months had higher species diversity, abundance and biomass than those on `tolerant' reefs. Fish assemblages on `tolerant' reefs were also more strongly influenced by the introduction of a mesopredator ( Cephalopholis boenak). Mesopredators on `tolerant' reefs had lower lipid content in their muscle tissue by the end of the 6-week experiment. Such sublethal energetic costs can compromise growth, fecundity, and survivorship, resulting in unexpected population declines in long-lived mesopredators. This study provides valuable insight into the altered trophodynamics of future coral reef ecosystems, highlighting the potentially increased vulnerability of reef fish assemblages to predation as reef structure declines, and the cost of changing prey availability on mesopredator condition.

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

PubMed

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

2015-12-01

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

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...

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...

Suitable Environmental Ranges for Potential Coral Reef Habitats in the Tropical Ocean

PubMed Central

Guan, Yi; Hohn, Sönke; Merico, Agostino

2015-01-01

Coral reefs are found within a limited range of environmental conditions or tolerance limits. Estimating these limits is a critical prerequisite for understanding the impacts of climate change on the biogeography of coral reefs. Here we used the diagnostic model ReefHab to determine the current environmental tolerance limits for coral reefs and the global distribution of potential coral reef habitats as a function of six factors: temperature, salinity, nitrate, phosphate, aragonite saturation state, and light. To determine these tolerance limits, we extracted maximum and minimum values of all environmental variables in corresponding locations where coral reefs are present. We found that the global, annually averaged tolerance limits for coral reefs are 21.7—29.6 °C for temperature, 28.7—40.4 psu for salinity, 4.51 μmol L-1 for nitrate, 0.63 μmol L-1 for phosphate, and 2.82 for aragonite saturation state. The averaged minimum light intensity in coral reefs is 450 μmol photons m-2 s-1. The global area of potential reef habitats calculated by the model is 330.5 × 103 km2. Compared with previous studies, the tolerance limits for temperature, salinity, and nutrients have not changed much, whereas the minimum value of aragonite saturation in coral reef waters has decreased from 3.28 to 2.82. The potential reef habitat area calculated with ReefHab is about 121×103 km2 larger than the area estimated from the charted reefs, suggesting that the growth potential of coral reefs is higher than currently observed. PMID:26030287

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

PubMed

Guan, Yi; Hohn, Sönke; Merico, Agostino

2015-01-01

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

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

PubMed

Diaz-Pulido, Guillermo; McCook, Laurence J; Dove, Sophie; Berkelmans, Ray; Roff, George; Kline, David I; Weeks, Scarla; Evans, Richard D; Williamson, David H; Hoegh-Guldberg, Ove

2009-01-01

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

Coral Reef Community Composition in the Context of Disturbance History on the Great Barrier Reef, Australia

PubMed Central

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

2014-01-01

Much research on coral reefs has documented differential declines in coral and associated organisms. In order to contextualise this general degradation, research on community composition is necessary in the context of varied disturbance histories and the biological processes and physical features thought to retard or promote recovery. We conducted a spatial assessment of coral reef communities across five reefs of the central Great Barrier Reef, Australia, with known disturbance histories, and assessed patterns of coral cover and community composition related to a range of other variables thought to be important for reef dynamics. Two of the reefs had not been extensively disturbed for at least 15 years prior to the surveys. Three of the reefs had been severely impacted by crown-of-thorns starfish outbreaks and coral bleaching approximately a decade before the surveys, from which only one of them was showing signs of recovery based on independent surveys. We incorporated wave exposure (sheltered and exposed) and reef zone (slope, crest and flat) into our design, providing a comprehensive assessment of the spatial patterns in community composition on these reefs. Categorising corals into life history groupings, we document major coral community differences in the unrecovered reefs, compared to the composition and covers found on the undisturbed reefs. The recovered reef, despite having similar coral cover, had a different community composition from the undisturbed reefs, which may indicate slow successional processes, or a different natural community dominance pattern due to hydrology and other oceanographic factors. The variables that best correlated with patterns in the coral community among sites included the density of juvenile corals, herbivore fish biomass, fish species richness and the cover of macroalgae. Given increasing impacts to the Great Barrier Reef, efforts to mitigate local stressors will be imperative to encouraging coral communities to persist into the future. PMID:24983747

76 FR 66021 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Generic Annual Catch Limits...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-25

..., Shrimp, and Coral and Coral Reefs Fishery Management Plans for the Gulf of Mexico (FMPs) as prepared and... fisheries for reef fish, red drum, shrimp, and coral and coral reefs of the Gulf of Mexico (Gulf) are... remove octocorals from the Coral and Coral Reefs FMP. Most octocorals are harvested in waters under the...

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...

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.

Predicting climate-driven regime shifts versus rebound potential in coral reefs.

PubMed

Graham, Nicholas A J; Jennings, Simon; MacNeil, M Aaron; Mouillot, David; Wilson, Shaun K

2015-02-05

Climate-induced coral bleaching is among the greatest current threats to coral reefs, causing widespread loss of live coral cover. Conditions under which reefs bounce back from bleaching events or shift from coral to algal dominance are unknown, making it difficult to predict and plan for differing reef responses under climate change. Here we document and predict long-term reef responses to a major climate-induced coral bleaching event that caused unprecedented region-wide mortality of Indo-Pacific corals. Following loss of >90% live coral cover, 12 of 21 reefs recovered towards pre-disturbance live coral states, while nine reefs underwent regime shifts to fleshy macroalgae. Functional diversity of associated reef fish communities shifted substantially following bleaching, returning towards pre-disturbance structure on recovering reefs, while becoming progressively altered on regime shifting reefs. We identified threshold values for a range of factors that accurately predicted ecosystem response to the bleaching event. Recovery was favoured when reefs were structurally complex and in deeper water, when density of juvenile corals and herbivorous fishes was relatively high and when nutrient loads were low. Whether reefs were inside no-take marine reserves had no bearing on ecosystem trajectory. Although conditions governing regime shift or recovery dynamics were diverse, pre-disturbance quantification of simple factors such as structural complexity and water depth accurately predicted ecosystem trajectories. These findings foreshadow the likely divergent but predictable outcomes for reef ecosystems in response to climate change, thus guiding improved management and adaptation.

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

PubMed Central

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

2015-01-01

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

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

PubMed

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

2015-01-01

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

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

PubMed

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

2014-09-01

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

A Global Estimate of the Number of Coral Reef Fishers.

PubMed

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

2013-01-01

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

A Global Estimate of the Number of Coral Reef Fishers

PubMed Central

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

2013-01-01

Overfishing threatens coral reefs worldwide, yet there is no reliable estimate on the number of reef fishers globally. We address this data gap by quantifying the number of reef fishers on a global scale, using two approaches - the first estimates reef fishers as a proportion of the total number of marine fishers in a country, based on the ratio of reef-related to total marine fish landed values. The second estimates reef fishers as a function of coral reef area, rural coastal population, and fishing pressure. In total, we find that there are 6 million reef fishers in 99 reef countries and territories worldwide, of which at least 25% are reef gleaners. Our estimates are an improvement over most existing fisher population statistics, which tend to omit accounting for gleaners and reef fishers. Our results suggest that slightly over a quarter of the world’s small-scale fishers fish on coral reefs, and half of all coral reef fishers are in Southeast Asia. Coral reefs evidently support the socio-economic well-being of numerous coastal communities. By quantifying the number of people who are employed as reef fishers, we provide decision-makers with an important input into planning for sustainable coral reef fisheries at the appropriate scale. PMID:23840327

Carbon Cycle Model of a Hawaiian Barrier Reef under Rising Ocean Acidification and Temperature Conditions of the Anthropocene

NASA Astrophysics Data System (ADS)

Drupp, P. S.; Mackenzie, F. T.; De Carlo, E. H.; Guidry, M.

2015-12-01

A CO2-carbonic acid system biogeochemical box model (CRESCAM, Coral Reef and Sediment Carbonate Model) of the barrier reef flat in Kaneohe Bay, Hawai'i was developed to determine how increasing temperature and dissolved inorganic carbon (DIC) content of open ocean source waters, resulting from rising anthropogenic CO2 emissions and ocean acidification, affect the CaCO3budget of coral reef ecosystems. CRESCAM consists of 17 reservoirs and 59 fluxes, including a surface water column domain, a two-layer permeable sediment domain, and a coral framework domain. Physical, chemical, and biological processes such as advection, carbonate precipitation/dissolution, and net ecosystem production and calcification were modeled. The initial model parameters were constrained by experimental and field data from previous coral reef studies, mostly in Kaneohe Bay over the past 50 years. The field studies include data collected by our research group for both the water column and sediment-porewater system.The model system, initially in a quasi-steady state condition estimated for the early 21st century, was perturbed using future projections to the year 2100 of the Anthropocene of atmospheric CO2 ­concentrations, temperature, and source water DIC. These perturbations were derived from the most recent (2013) IPCC's Representative Concentration Pathway (RCP) scenarios, which predict CO2 atmospheric concentrations and temperature anomalies out to 2100. A series of model case studies were also performed whereby one or more parameters (e.g., coral calcification response to declining surface water pH) were altered to investigate potential future outcomes. Our model simulations predict that although the Kaneohe Bay barrier reef will likely see a significant decline in NEC over the coming century, it is unlikely to reach a state of net erosion - a result contrary to several global coral reef model projections. In addition, we show that depending on the future response of NEP and NEC to OA and rising temperatures, the surface waters could switch from being a present-day source of CO2 to the atmosphere to a future sink. This ecosystem specific model can be applied to any reef system where data are available to constrain the initial model state and is a powerful tool for examining future changes in coral reef carbon budgets.

Experimental studies of rapid bioerosion of coral reefs in the Galápagos Islands

NASA Astrophysics Data System (ADS)

Reaka-Kudla, M. L.; Feingold, J. S.; Glynn, W.

1996-06-01

Experimental carbonate blocks of coral skeleton, Porites lobata (PL), and cathedral limestone (LS) were deployed for 14.8 months at shallow (5 6 m) and deep (11 13m) depths on a severely bioeroded coral reef, Champion Island, Galápagos Islands, Ecuador. Sea urchins ( Eucidaris thouarsii) were significantly more abundant at shallow versus deep sites. Porites lobata blocks lost an average of 25.4 kg m-2yr-1 (23.71 m-2yr-1 or 60.5% decrease yr-1). Losses did not vary significantly at depths tested. Internal bioeroders excavated an average of 2.6 kg m-2 yr-1 (2.41 m-2 yr-1 or 0.6% decrease yr-1), while external bioeroders removed an average of 22.8 kg m-2 yr-1). (21.31 m-2 yr-1). or 59.9% decrease yr-1). few encrusting organisms were observed on the PL blocks. Cathedral limestone blocks lost an average of 4.1 kg m-2 yr-1). (1.81 m-2 yr-1). or 4.6% decrease yr-'), also with no relation to depth. Internal bioeroders excavated an average of 0.6 kg m-2 yr-1). (0.31 m-2 yr-1). or 0.7% decrease yr-1). and external bioeroders removed an average of 3.5 kg m-2 yr-1). (1.51 m-2 yr-1). or 3.9% decrease yr-1). from the LS blocks. Most (57.6%) encrustation occurred on the bottom of LS blocks, and there was more accretion on block bottoms in deep (61.4 mg cm-2 yr-1). versus shallow (35.0 mg cm-2 yr-1) sites. External bioerosion reduced the average height of the reef framework by 0.2 cm yr-1). for hard substrata (represented by LS) and 2.3 cm yr-1). for soft substrata (represented by PL). The results of this study suggest that coral reef frameworks in the Galápagos Islands are in serious jeopardy. If rates of coral recruitment do not increase, and if rates of bioerosion do not decline, coral reefs in the Galápagos Islands could be eliminated entirely.

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.

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...

76 FR 18775 - Pacific Remote Islands Marine National Monument; Monument Management Plan, Comprehensive...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-05

... equator. These areas have deep-water corals, coral reefs, corals in near-pristine condition, and predator... will be revised as needed. Kingman Reef and Palmyra Atoll have relatively undisturbed coral reefs, with the highest levels of coral diversity in the central Pacific Ocean. Kingman Reef has the greatest...

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...

Healthy coral reefs may assure coastal protection in face of climate change related sea level rise

NASA Astrophysics Data System (ADS)

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

2016-12-01

Coral reefs are diverse ecosystems that support millions of people worldwide providing crucial services, of which, coastal protection is one of the most relevant. The efficiency of coral reefs in protecting coastlines and dissipating waves is directly linked to the cover of living corals and three dimensional reef structural complexity. Climate change and human impacts are leading to severe global reductions in live coral cover, posing serious concerns regarding the capacity of degraded reef systems in protecting tropical coastal regions. Although it is known that the loss of structurally complex reefs may lead to greater erosion of coastlines, this process has rarely been quantified and it is still unknown whether the maintenance of healthy reefs through conservation will be enough to guarantee coastal protection during rising sea levels. We show that a significant loss of wave dissipation and a subsequent increase in back-reef wave height (up to 5 times present wave height) could occur even at present sea level if living corals are lost and reef structural complexity is reduced. Yet we also show that healthy reefs, measured by structural complexity and efficiency of vertical reef accretion, may maintain their present capacity of wave dissipation even under rising sea levels. Our results indicate that the health of coral reefs and not sea level rise will be the major determinant of the coastal protection services provided by coral reefs and calls for investments into coral reef conservation to ensure the future protection of tropical coastal communities.

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

NASA Astrophysics Data System (ADS)

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

2010-12-01

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

The Coral Reef pH-stat: An Important Defense Against Ocean Acidification? (Invited)

NASA Astrophysics Data System (ADS)

Andersson, A. J.; Yeakel, K.; Bates, N.; de Putron, S.; Collins, A.

2013-12-01

Concerns have been raised on how coral reefs will be affected by ocean acidification (OA), but there are currently no direct predictions on how seawater CO2 chemistry and pH within coral reefs might change in response to OA. Projections of future changes in seawater pH and aragonite saturation state have only been applied to open ocean conditions surrounding coral reef environments rather than the reef systems themselves. The seawater CO2 chemistry within heterogenous coral reef systems can be significantly different from that of the open ocean depending on the residence time, community composition and the major biogeochemical processes occurring on the reef, i.e., net ecosystem organic carbon production and calcification, which combined act to modify the seawater chemistry. We argue that these processes and coral reefs in general could as a pH-stat, partly regulating seawater pH on the reef and offsetting changes in seawater chemistry imposed by ocean acidification. Based on observations from the Bermuda coral reef, we show that a range of anticipated biogeochemical responses of coral reef communities to OA by the end of this century could partially offset changes in seawater pH by an average of 12% to 24%.

The Role of Turtles as Coral Reef Macroherbivores

PubMed Central

Goatley, Christopher H. R.; Hoey, Andrew S.; Bellwood, David R.

2012-01-01

Herbivory is widely accepted as a vital function on coral reefs. To date, the majority of studies examining herbivory in coral reef environments have focused on the roles of fishes and/or urchins, with relatively few studies considering the potential role of macroherbivores in reef processes. Here, we introduce evidence that highlights the potential role of marine turtles as herbivores on coral reefs. While conducting experimental habitat manipulations to assess the roles of herbivorous reef fishes we observed green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) showing responses that were remarkably similar to those of herbivorous fishes. Reducing the sediment load of the epilithic algal matrix on a coral reef resulted in a forty-fold increase in grazing by green turtles. Hawksbill turtles were also observed to browse transplanted thalli of the macroalga Sargassum swartzii in a coral reef environment. These responses not only show strong parallels to herbivorous reef fishes, but also highlight that marine turtles actively, and intentionally, remove algae from coral reefs. When considering the size and potential historical abundance of marine turtles we suggest that these potentially valuable herbivores may have been lost from many coral reefs before their true importance was understood. PMID:22768189

The role of turtles as coral reef macroherbivores.

PubMed

Goatley, Christopher H R; Hoey, Andrew S; Bellwood, David R

2012-01-01

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

Primary production of coral ecosystems in the Vietnamese coastal and adjacent marine waters

NASA Astrophysics Data System (ADS)

Tac-An, Nguyen; Minh-Thu, Phan; Cherbadji, I. I.; Propp, M. V.; Odintsov, V. S.; Propp, L. H.

2013-11-01

Coral reef ecosystems in coastal waters and islands of Vietnam have high primary production. Average gross primary production (GPP) in coral reef waters was 0.39 g C m-2 day-1. GPP of corals ranged from 3.12 to 4.37 g C m-2 day-1. GPP of benthic microalgae in coral reefs ranged from 2 to 10 g C m-2 day-1. GPP of macro-algae was 2.34 g C m-2 day-1. Therefore, the total of GPP of whole coral reef ecosystems could reach 7.85 to 17.10 g C m-2 day-1. Almost all values of the ratio of photosynthesis to respiration in the water bodies are higher than 1, which means these regions are autotrophic systems. Wire variation of GPP in coral reefs was contributed by species abundance of coral and organisms, nutrient supports and environmental characteristics of coral ecosystems. Coral reefs play an important ecological role of biogeochemical cycling of nutrients in waters around the reefs. These results contribute valuable information for the protection, conservation and sustainable exploitation of the natural resources in coral reef ecosystems in Vietnam.

Developing a multi-stressor gradient for coral reefs

EPA Science Inventory

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

Species-area relationships in coral communities: evaluating mechanisms for a commonly observed pattern

NASA Astrophysics Data System (ADS)

Huntington, B. E.; Lirman, D.

2012-12-01

Landscape-scale attributes of patch size, spatial isolation, and topographic complexity are known to influence diversity and abundance in terrestrial and marine systems, but remain collectively untested for reef-building corals. To investigate the relationship between the coral assemblage and seascape variation in reef habitats, we took advantage of the distinct boundaries, spatial configurations, and topographic complexities among artificial reef patches to overcome the difficulties of manipulating natural reefs. Reef size (m2) was found to be the foremost predictor of coral richness in accordance with species-area relationship predictions. Larger reefs were also found to support significantly higher colony densities, enabling us to reject the null hypothesis of random placement (a sampling artifact) in favor of target area predictions that suggest greater rates of immigration on larger reefs. Unlike the pattern previously documented for reef fishes, topographic complexity was not a significant predictor of any coral assemblage response variable, despite the range of complexity values sampled. Lastly, coral colony density was best explained by both increasing reef size and decreasing reef spatial isolation, a pattern found exclusively among brooding species with shorter larval dispersal distances. We conclude that seascape attributes of reef size and spatial configuration within the seascape can influence the species richness and abundance of the coral community at relatively small spatial scales (<1 km). Specifically, we demonstrate how patterns in the coral communities that have naturally established on these manipulated reefs agree with the target area and island biogeography mechanisms to drive species-area relationships in reef-building corals. Based on the patterns documented in artificial reefs, habitat degradation that results in smaller, more isolated natural reefs may compromise coral diversity.

Ocean acidification causes bleaching and productivity loss in coral reef builders.

PubMed

Anthony, K R N; Kline, D I; Diaz-Pulido, G; Dove, S; Hoegh-Guldberg, O

2008-11-11

Ocean acidification represents a key threat to coral reefs by reducing the calcification rate of framework builders. In addition, acidification is likely to affect the relationship between corals and their symbiotic dinoflagellates and the productivity of this association. However, little is known about how acidification impacts on the physiology of reef builders and how acidification interacts with warming. Here, we report on an 8-week study that compared bleaching, productivity, and calcification responses of crustose coralline algae (CCA) and branching (Acropora) and massive (Porites) coral species in response to acidification and warming. Using a 30-tank experimental system, we manipulated CO(2) levels to simulate doubling and three- to fourfold increases [Intergovernmental Panel on Climate Change (IPCC) projection categories IV and VI] relative to present-day levels under cool and warm scenarios. Results indicated that high CO(2) is a bleaching agent for corals and CCA under high irradiance, acting synergistically with warming to lower thermal bleaching thresholds. We propose that CO(2) induces bleaching via its impact on photoprotective mechanisms of the photosystems. Overall, acidification impacted more strongly on bleaching and productivity than on calcification. Interestingly, the intermediate, warm CO(2) scenario led to a 30% increase in productivity in Acropora, whereas high CO(2) lead to zero productivity in both corals. CCA were most sensitive to acidification, with high CO(2) leading to negative productivity and high rates of net dissolution. Our findings suggest that sensitive reef-building species such as CCA may be pushed beyond their thresholds for growth and survival within the next few decades whereas corals will show delayed and mixed responses.

Fine-scale environmental specialization of reef-building corals might be limiting reef recovery in the Florida Keys.

PubMed

Kenkel, Carly D; Almanza, Albert T; Matz, Mikhail V

2015-12-01

Despite decades of monitoring global reef decline, we are still largely unable to explain patterns of reef deterioration at local scales, which precludes the development of effective management strategies. Offshore reefs of the Florida Keys, USA, experience milder temperatures and lower nutrient loads in comparison to inshore reefs yet remain considerably more degraded than nearshore patch reefs. A year-long reciprocal transplant experiment of the mustard hill coral (Porites astreoides) involving four source and eight transplant locations reveals that corals adapt and/or acclimatize to their local habitat on a < 10-km scale. Surprisingly, transplantation to putatively similar environmental types (e.g., offshore corals moved to a novel offshore site, or along-shore transplantation) resulted in greater reductions in fitness proxies, such as coral growth, than cross-channel transplantation between inshore and offshore reefs. The only abiotic factor showing significantly greater differences between along-shore sites was daily temperature range extremes (rather than the absolute high or low temperatures reached), providing a possible explanation for this pattern. Offshore-origin corals exhibited significant growth reductions at sites with greater daily temperature ranges, which explained up to 39% of the variation in their mass gain. In contrast, daily temperature range explained at most 9% of growth variation in inshore-origin corals, suggesting that inshore corals are more tolerant of high-frequency temperature fluctuations. Finally, corals incur trade-offs when specializing to their native reef. Across reef locations the coefficient of selection against coral transplants was 0.07 ± 0.02 (mean ± SE). This selection against immigrants could hinder the ability of corals to recolonize devastated reefs, whether through assisted migration efforts or natural recruitment events, providing a unifying explanation for observed patterns of coral decline in this reef system.

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.

50 CFR 622.1 - Purpose and scope.

Code of Federal Regulations, 2014 CFR

2014-10-01

... for Coral, Coral Reefs, and Live/Hard Bottom Habitats of the South Atlantic Region SAFMC South Atlantic.5 FMP for Coral and Coral reefs of the Gulf of Mexico GMFMC Gulf. FMP for Corals and Reef... CFMC Caribbean. FMP for the Red Drum Fishery of the Gulf of Mexico GMFMC Gulf.1 FMP for the Reef Fish...

50 CFR 622.1 - Purpose and scope.

Code of Federal Regulations, 2013 CFR

2013-10-01

... for Coral, Coral Reefs, and Live/Hard Bottom Habitats of the South Atlantic Region SAFMC South Atlantic.5 FMP for Coral and Coral reefs of the Gulf of Mexico GMFMC Gulf. FMP for Corals and Reef... CFMC Caribbean. FMP for the Red Drum Fishery of the Gulf of Mexico GMFMC Gulf.1 FMP for the Reef Fish...

Persistence and Change in Community Composition of Reef Corals through Present, Past, and Future Climates

PubMed Central

Edmunds, Peter J.; Adjeroud, Mehdi; Baskett, Marissa L.; Baums, Iliana B.; Budd, Ann F.; Carpenter, Robert C.; Fabina, Nicholas S.; Fan, Tung-Yung; Franklin, Erik C.; Gross, Kevin; Han, Xueying; Jacobson, Lianne; Klaus, James S.; McClanahan, Tim R.; O'Leary, Jennifer K.; van Oppen, Madeleine J. H.; Pochon, Xavier; Putnam, Hollie M.; Smith, Tyler B.; Stat, Michael; Sweatman, Hugh; van Woesik, Robert; Gates, Ruth D.

2014-01-01

The reduction in coral cover on many contemporary tropical reefs suggests a different set of coral community assemblages will dominate future reefs. To evaluate the capacity of reef corals to persist over various time scales, we examined coral community dynamics in contemporary, fossil, and simulated future coral reef ecosystems. Based on studies between 1987 and 2012 at two locations in the Caribbean, and between 1981 and 2013 at five locations in the Indo-Pacific, we show that many coral genera declined in abundance, some showed no change in abundance, and a few coral genera increased in abundance. Whether the abundance of a genus declined, increased, or was conserved, was independent of coral family. An analysis of fossil-reef communities in the Caribbean revealed changes in numerical dominance and relative abundances of coral genera, and demonstrated that neither dominance nor taxon was associated with persistence. As coral family was a poor predictor of performance on contemporary reefs, a trait-based, dynamic, multi-patch model was developed to explore the phenotypic basis of ecological performance in a warmer future. Sensitivity analyses revealed that upon exposure to thermal stress, thermal tolerance, growth rate, and longevity were the most important predictors of coral persistence. Together, our results underscore the high variation in the rates and direction of change in coral abundances on contemporary and fossil reefs. Given this variation, it remains possible that coral reefs will be populated by a subset of the present coral fauna in a future that is warmer than the recent past. PMID:25272143

77 FR 46682 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-06

...: National Oceanic and Atmospheric Administration (NOAA). Title: Pacific Islands Region Coral Reef Ecosystems.... Average Hours per Response: Coral Reef Ecosystem permits, 2 hours; appeals, 3 hours; transshipment permits..., taking, or retaining any Potentially Harvested Coral Reef Taxa (PHCRT) in the coral reef ecosystem...

78 FR 67128 - Coral Reef Conservation Program; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-08

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Coral Reef Conservation Program; Meeting AGENCY: Coral Reef Conservation Program, Office of Ocean and Coastal Resource Management... meeting of the U.S. Coral Reef Task Force (USCRTF). The meeting will be held in Christiansted, U.S. Virgin...

Status and conservation of coral reefs in Costa Rica.

PubMed

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

2010-05-01

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

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

PubMed

Wild, Christian; Jantzen, Carin; Kremb, Stephan Georg

2014-01-01

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

Low coral cover in a high-CO2 world

NASA Astrophysics Data System (ADS)

Hoegh-Guldberg, Ove

2005-09-01

Coral reefs generally exist within a relatively narrow band of temperatures, light, and seawater aragonite saturation states. The growth of coral reefs is minimal or nonexistent outside this envelope. Climate change, through its effect on ocean temperature, has already had an impact on the world's coral reefs, with almost 30% of corals having disappeared since the beginning of the 1980s. Abnormally warm temperatures cause corals to bleach (lose their brown dinoflagellate symbionts) and, if elevated for long enough, to die. Increasing atmospheric CO2 is also potentially affecting coral reefs by lowering the aragonite saturation state of seawater, making carbonate ions less available for calcification. The synergistic interaction of elevated temperature and CO2 is likely to produce major changes to coral reefs over the next few decades and centuries. Known tolerances of corals to projected changes to sea temperatures indicate that corals are unlikely to remain abundant on reefs and could be rare by the middle of this century if the atmospheric CO2 concentration doubles or triples. The combination of changes to sea temperature and carbonate ion availability could trigger large-scale changes in the biodiversity and function of coral reefs. The ramifications of these changes for the hundred of millions of coral reef-dependent people and industries living in a high-CO2 world have yet to be properly defined. The weight of evidence suggests, however, that projected changes will cause major shifts in the prospects for industries and societies that depend on having healthy coral reefs along their coastlines.

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.

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

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

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-26

... DEPARTMENT OF THE INTERIOR National Park Service Coral Reef Restoration Plan, Draft Programmatic... Coral Reef Restoration Plan, Biscayne National Park. SUMMARY: Pursuant to the National Environmental... availability of a Draft Programmatic Environmental Impact Statement (DEIS) for the Coral Reef Restoration Plan...

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

EPA Science Inventory

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

How cold-water coral mounds modify their physical environment and therefore influence reef development

NASA Astrophysics Data System (ADS)

Mienis, F.; Duineveld, G.; Lavaleye, M.; van Haren, H.; Mohn, C.; Cyr, F.

2015-12-01

Cold-water coral framework acts as a sediment trap and as a result kilometres long and up to 360m high mound structures have formed on the SE Rockall Bank. Earlier observations showed that most of the mounds have their summits around 550 m water depth and summits have been reported as being covered with living coral. Pelagia cruises in 2012 and 2013 revealed completely new insights in mound development. Video transects across mounds with different morphology showed that summits of the highest and largest mounds are presently not covered by living coral as opposed to smaller and lower mounds which are covered with a thriving living coral framework. Measurements in the water column with CTD and near-bottom with benthic landers and thermistor string showed that turbulence is likely the most important factor influencing nutrient and food supply and thus coral growth. It seems that the large mounds have outgrown themselves and that their relatively large size and flat summits are limiting turbulence, thereby limiting oxygen, nutrient and food replenishment. Redistribution of nutrients, oxygen and food is vital for ecosystem functioning and reef development. The presence of a healthy coral cover on the summits of the small mounds was also shown by the vertical mound growth rate measured in sediment cores. These showed fourfold higher sedimentation rates during the Holocene on small mounds compared to highest mounds.

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.

Satellite Remote Sensing of Coral Reefs: By Learning about Coral Reefs, Students Gain an Understanding of Ecosystems and How Cutting-Edge Technology Can Be Used to Study Ecological Change

ERIC Educational Resources Information Center

Palandro, David; Thoms, Kristin; Kusek, Kristen; Muller-Karger, Frank; Greely, Teresa

2005-01-01

Coral reefs are one of the most important ecosystems on the planet, providing sustenance to both marine organisms and humans. Yet they are also one of the most endangered ecosystems as coral reef coverage has declined dramatically in the past three decades. Researchers continually seek better ways to map coral reef coverage and monitor changes…

77 FR 66 - Western Pacific Fisheries; 2012 Annual Catch Limits and Accountability Measures

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-03

... proposes annual catch limits for western Pacific bottomfish, crustacean, precious coral, and coral reef... specify ACLs for bottomfish, crustacean, precious coral, and coral reef ecosystem fishery MUS in American... bottomfish, crustacean, precious coral, or coral reef ecosystem MUS in the PRIA because commercial fishing is...

78 FR 6798 - Western Pacific Fisheries; 2013 Annual Catch Limits and Accountability Measures

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-31

... proposes annual catch limits for western Pacific bottomfish, crustacean, precious coral, and coral reef... ACLs for bottomfish, crustacean, precious coral, and coral reef ecosystem fishery MUS in American Samoa... to 2012. NMFS is not proposing ACLs for bottomfish, crustacean, precious coral, or coral reef...

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.

Catastrophic impact of typhoon waves on coral communities in the Ryukyu Islands under global warming

NASA Astrophysics Data System (ADS)

Hongo, Chuki; Kawamata, Hideki; Goto, Kazuhisa

2012-06-01

Typhoon-generated storm waves generally cause mechanical damage to coral communities on present-day reefs, and the magnitude and extent of damage is predicted to increase in the near future as a result of global warming. Therefore, a comprehensive understanding of potential future scenarios of reef ecosystems is of prime interest. This study assesses the current status of coral communities on Ibaruma reef, Ryukyu Islands, on the basis of field observations, engineering and fluid dynamic models, and calculations of wave motion, and predicts the potential effects of a super-extreme typhoon (incident wave height,H = 20 m; wave period, T = 20 s) on the reef. On the present-day reef, massive corals occur in shallow lagoons and tabular corals occur from the reef crest to the reef slope. The observed distribution of corals, which is frequently attacked by moderate (H = 10 m, T = 10 s) and extreme (H = 10 m, T = 15 s) typhoons, is consistent with the predictions of engineering models. Moreover, this study indicates that if a super-extreme typhoon attacks the reef in the near future, massive corals will survive in the shallow lagoons but tabular corals on the reef crest and reef slope will be severely impacted. The findings imply that super-extreme typhoons will cause a loss of species diversity, as the tabular corals are important reef builders and are critical to the maintenance of reef ecosystems. Consequently, reef restoration is a key approach to maintaining reef ecosystems in the wake of super-extreme typhoons.

The growth of coral reef science in the Gulf: a historical perspective.

PubMed

Burt, John A

2013-07-30

Coral reef science has grown exponentially in recent decades in the Gulf. Analysis of literature from 1950 to 2012 identified 270 publications on coral reefs in the Gulf, half of which were published in just the past decade. This paper summarizes the growth and evolution of coral reef science in the Gulf by examining when, where and how research has been conducted on Gulf reefs, who conducted that research, and what themes and taxa have dominated scientific interest. The results demonstrate that there has been significant growth in our understanding of the valuable coral reefs of the Gulf, but also highlight the fact that we are documenting an increasingly degraded ecosystem. Reef scientists must make a concerted effort to improve dialogue with regional reef management and decision-makers if we are to stem the tide of decline in coral reefs in the Gulf. Copyright © 2013 Elsevier Ltd. All rights reserved.

Conservation status and spatial patterns of AGRRA vitality indices in Southwestern Atlantic reefs.

PubMed

Kikuchi, Ruy K P; Leão, Zelinda M A N; Oliveira, Marília D M

2010-05-01

Coral reefs along the Eastern Brazilian coast extend for a distance of 800 km from 12 degrees to 18 degrees S. They are the largest and the richest reefs of Brazil coasts, and represent the Southernmost coral reefs of the Southwestern Atlantic Ocean. Few reef surveys were performed in the 90's in reef areas of Bahia State, particularly in the Abrolhos reef complex, in the Southernmost side of the state. A monitoring program applying the Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol was initiated in 2000, in the Abrolhos National Marine Park, after the creation of the South Tropical America (STA) Regional Node of the Global Coral Reef Monitoring Network (GCRMN) by the end of 1999. From that time up to 2005, nine reef surveys were conducted along the coast of the State of Bahia, including 26 reefs, with 95 benthic sites, 280 benthic transects, 2025 quadrats and 3537 stony corals. Eighteen of the 26 investigated reefs were assessed once and eight reefs of Abrolhos were surveyed twice to four times. The MDS ordination, analysis of similarity (ANOSIM, one way and two-way nested layouts) and similarity percentages (SIMPER) tests were applied to investigate the spatial and temporal patterns of reef vitality. Four indicators of the coral vitality: live coral cover, the density of the larger corals (colonics > 20cm per reef site) and of the coral recruits (colonies < 2cm per square meter), and the percentage of macroalgae indicate that the nearshore reefs, which are located less than 5 km from the coast, are in poorer condition than the reefs located more than 5 km off the coast. A higher density of coral colonies, lower macroalgal index, higher relative percent of turf algae and higher density of coral recruits in offshore reefs compared to the nearshore reefs are the conditions that contribute more than 80% to the dissimilarity between them. The offshore reefs are in better vital condition than the nearshore reefs and have a set of vitality indices more closely related to the Northwestern Atlantic reefs than the nearshore reef. These have been most severely impacted by the effects of direct human activities such as cuthrophic waters associated with sewage pollution, higher sedimentation rates and water turbidity, inadequate use of the reefs and over exploitation of their resources. The implementation of a more effective coral reef monitoring program in Bahia is mandatory, in order to improve the strategies for protection and management efforts of the reefs.

Improved water quality can ameliorate effects of climate change on corals.

PubMed

Wooldridge, Scott A; Done, Terence J

2009-09-01

The threats of wide-scale coral bleaching and reef demise associated with anthropogenic climate change are widely known. Moreover, rates of genetic adaptation and/or changes in the coral-zooxanthella partnerships are considered unlikely to be sufficiently fast for corals to acquire increased physiological resistance to increasing sea temperatures and declining pH. However, it has been suggested that coral reef resilience to climate change may be improved by good local management of coral reefs, including management of water quality. Here, using major data sets from the Great Barrier Reef (GBR), Australia, we investigate geographic patterns of coral bleaching in 1998 and 2002 and outline a synergism between heat stress and nutrient flux as a major causative mechanism for those patterns. The study provides the first concrete evidence for the oft-expressed belief that improved coral reef management will increase the regional-scale survival prospects of coral reefs to global climate change.

Predator crown-of-thorns starfish (Acanthaster planci) outbreak, mass mortality of corals, and cascading effects on reef fish and benthic communities.

PubMed

Kayal, Mohsen; Vercelloni, Julie; Lison de Loma, Thierry; Bosserelle, Pauline; Chancerelle, Yannick; Geoffroy, Sylvie; Stievenart, Céline; Michonneau, François; Penin, Lucie; Planes, Serge; Adjeroud, Mehdi

2012-01-01

Outbreaks of the coral-killing seastar Acanthaster planci are intense disturbances that can decimate coral reefs. These events consist of the emergence of large swarms of the predatory seastar that feed on reef-building corals, often leading to widespread devastation of coral populations. While cyclic occurrences of such outbreaks are reported from many tropical reefs throughout the Indo-Pacific, their causes are hotly debated, and the spatio-temporal dynamics of the outbreaks and impacts to reef communities remain unclear. Based on observations of a recent event around the island of Moorea, French Polynesia, we show that Acanthaster outbreaks are methodic, slow-paced, and diffusive biological disturbances. Acanthaster outbreaks on insular reef systems like Moorea's appear to originate from restricted areas confined to the ocean-exposed base of reefs. Elevated Acanthaster densities then progressively spread to adjacent and shallower locations by migrations of seastars in aggregative waves that eventually affect the entire reef system. The directional migration across reefs appears to be a search for prey as reef portions affected by dense seastar aggregations are rapidly depleted of living corals and subsequently left behind. Coral decline on impacted reefs occurs by the sequential consumption of species in the order of Acanthaster feeding preferences. Acanthaster outbreaks thus result in predictable alteration of the coral community structure. The outbreak we report here is among the most intense and devastating ever reported. Using a hierarchical, multi-scale approach, we also show how sessile benthic communities and resident coral-feeding fish assemblages were subsequently affected by the decline of corals. By elucidating the processes involved in an Acanthaster outbreak, our study contributes to comprehending this widespread disturbance and should thus benefit targeted management actions for coral reef ecosystems.

Assessing the spatial distribution of coral bleaching using small unmanned aerial systems

NASA Astrophysics Data System (ADS)

Levy, Joshua; Hunter, Cynthia; Lukacazyk, Trent; Franklin, Erik C.

2018-06-01

Small unmanned aerial systems (sUAS) are an affordable, effective complement to existing coral reef monitoring and assessment tools. sUAS provide repeatable low-altitude, high-resolution photogrammetry to address fundamental questions of spatial ecology and community dynamics for shallow coral reef ecosystems. Here, we qualitatively describe the use of sUAS to survey the spatial characteristics of coral cover and the distribution of coral bleaching across patch reefs in Kānéohe Bay, Hawaii, and address limitations and anticipated technology advancements within the field of UAS. Overlapping sub-decimeter low-altitude aerial reef imagery collected during the 2015 coral bleaching event was used to construct high-resolution reef image mosaics of coral bleaching responses on four Kānéohe Bay patch reefs, totaling 60,000 m2. Using sUAS imagery, we determined that paled, bleached and healthy corals on all four reefs were spatially clustered. Comparative analyses of data from sUAS imagery and in situ diver surveys found as much as 14% difference in coral cover values between survey methods, depending on the size of the reef and area surveyed. When comparing the abundance of unhealthy coral (paled and bleached) between sUAS and in situ diver surveys, we found differences in cover from 1 to 49%, depending on the depth of in situ surveys, the percent of reef area covered with sUAS surveys and patchiness of the bleaching response. This study demonstrates the effective use of sUAS surveys for assessing the spatial dynamics of coral bleaching at colony-scale resolutions across entire patch reefs and evaluates the complementarity of data from both sUAS and in situ diver surveys to more accurately characterize the spatial ecology of coral communities on reef flats and slopes.

50 CFR 665.421 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Definitions. As used in §§ 665.420 through 665.439: Mariana coral reef ecosystem management unit species (Mariana coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.621 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... § 665.621 Definitions. As used in §§ 665.620 through 665.639: PRIA coral reef ecosystem management unit species (PRIA coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic...

50 CFR 665.221 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... As used in §§ 665.220 through 665.239: Hawaii coral reef ecosystem management unit species (Hawaii coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.621 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... § 665.621 Definitions. As used in §§ 665.620 through 665.639: PRIA coral reef ecosystem management unit species (PRIA coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic...

50 CFR 665.221 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... As used in §§ 665.220 through 665.239: Hawaii coral reef ecosystem management unit species (Hawaii coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.221 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... As used in §§ 665.220 through 665.239: Hawaii coral reef ecosystem management unit species (Hawaii coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.421 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Definitions. As used in §§ 665.420 through 665.439: Mariana coral reef ecosystem management unit species (Mariana coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.621 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... § 665.621 Definitions. As used in §§ 665.620 through 665.639: PRIA coral reef ecosystem management unit species (PRIA coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic...

50 CFR 665.421 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Definitions. As used in §§ 665.420 through 665.439: Mariana coral reef ecosystem management unit species (Mariana coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

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

EPA Science Inventory

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

77 FR 12243 - Proposed Information Collection; Comment Request; Pacific Islands Region Coral Reef Ecosystems...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-29

... Collection; Comment Request; Pacific Islands Region Coral Reef Ecosystems Permit Form AGENCY: National... using a vessel to fish for Western Pacific coral reef ecosystem management unit species in the... allowed in the regulations; or (3) fishing for, taking, or retaining any Potentially Harvested Coral Reef...

50 CFR 665.121 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Definitions. As used in §§ 665.120 through 665.139: American Samoa coral reef ecosystem management unit species (American Samoa coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic...

50 CFR 665.421 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Definitions. As used in §§ 665.420 through 665.439: Mariana coral reef ecosystem management unit species (Mariana coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.221 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... As used in §§ 665.220 through 665.239: Hawaii coral reef ecosystem management unit species (Hawaii coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.121 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Definitions. As used in §§ 665.120 through 665.139: American Samoa coral reef ecosystem management unit species (American Samoa coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic...

50 CFR 665.421 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Definitions. As used in §§ 665.420 through 665.439: Mariana coral reef ecosystem management unit species (Mariana coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.621 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... § 665.621 Definitions. As used in §§ 665.620 through 665.639: PRIA coral reef ecosystem management unit species (PRIA coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-01

... Collection; Comment Request; Pacific Islands Region Coral Reef Ecosystems Logbook and Reporting AGENCY... with, or any U.S. citizen issued with, a Special Coral Reef Ecosystem Fishing Permit (authorized under the Fishery Management Plan for Coral Reef Ecosystems of the Western Pacific Region), to complete...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... the Western Pacific; Special Coral Reef Ecosystem Fishing Permit AGENCY: National Marine Fisheries... Reef Ecosystem Fishing Permit that would authorize Kampachi Farms, LLC, to culture and harvest a coral...: NMFS proposes to issue a Special Coral Reef Ecosystem Fishing Permit to Kampachi Farms, LLC, consistent...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-29

... DEPARTMENT OF THE INTERIOR National Park Service [2310-0003-422] Coral Reef Restoration Plan... for the Coral Reef Restoration Plan, Biscayne National Park. SUMMARY: Pursuant to the National... availability of a Final Programmatic Environmental Impact Statement for the Coral Reef Restoration Plan (Plan...

50 CFR 665.221 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... As used in §§ 665.220 through 665.239: Hawaii coral reef ecosystem management unit species (Hawaii coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic (post...

50 CFR 665.621 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... § 665.621 Definitions. As used in §§ 665.620 through 665.639: PRIA coral reef ecosystem management unit species (PRIA coral reef ecosystem MUS) means all of the Currently Harvested Coral Reef Taxa and Potentially Harvested Coral Reef Taxa listed in this section and which spend the majority of their non-pelagic...

Webinar on PTM with CMS

DTIC Science & Technology

2013-12-04

Coral Reef Dredging Project SAV Migrating Fish Coral Reef Dredging Project SAV Migrating Fish... Coral Reef Dredging Project SAV Migrating Fish Coral Reef Dredging Project Coastal and Hydraulics Laboratory 22 Dredging Materials and...Introduction to CMS Coastal and Hydraulics Laboratory Integrated waves , current, and sediment transport model in the Surface-water Modeling

Developing the Biological Condition Gradient (BCG), as a Tool for Describing the Condition of US Coral Reefs

EPA Science Inventory

Understanding effects of human activity on coral reefs requires knowing what characteristics constitute a high quality coral reef and identifying measurable criteria. The BCG is a conceptual model that describes how biological attributes of coral reefs change along a gradient of ...

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.

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

PubMed

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

2015-01-01

One striking feature of coral reef ecosystems is the complex benthic architecture which supports diverse and abundant fauna, particularly of reef fish. Reef-building corals are in decline worldwide, with a corresponding loss of live coral cover resulting in a loss of architectural complexity. Understanding the dynamics of the reef architecture is therefore important to envision the ability of corals to maintain functional habitats in an era of climate change. Here, we develop a mechanistic model of reef topographical complexity for contemporary Caribbean reefs. The model describes the dynamics of corals and other benthic taxa under climate-driven disturbances (hurricanes and coral bleaching). Corals have a simplified shape with explicit diameter and height, allowing species-specific calculation of their colony surface and volume. Growth and the mechanical (hurricanes) and biological erosion (parrotfish) of carbonate skeletons are important in driving the pace of extension/reduction in the upper reef surface, the net outcome being quantified by a simple surface roughness index (reef rugosity). The model accurately simulated the decadal changes of coral cover observed in Cozumel (Mexico) between 1984 and 2008, and provided a realistic hindcast of coral colony-scale (1-10 m) changing rugosity over the same period. We then projected future changes of Caribbean reef rugosity in response to global warming. Under severe and frequent thermal stress, the model predicted a dramatic loss of rugosity over the next two or three decades. Critically, reefs with managed parrotfish populations were able to delay the general loss of architectural complexity, as the benefits of grazing in maintaining living coral outweighed the bioerosion of dead coral skeletons. Overall, this model provides the first explicit projections of reef rugosity in a warming climate, and highlights the need of combining local (protecting and restoring high grazing) to global (mitigation of greenhouse gas emissions) interventions for the persistence of functional reef habitats. © 2014 John Wiley & Sons Ltd.

Geochemical partitioning of lead in biogenic carbonate sediments in a coral reef depositional environment.

PubMed

Horta-Puga, Guillermo

2017-03-15

The fate of trace elements in reef depositional environments has not been extensively investigated. The aim of this study was to determine the partitioning of Pb in sediments of the Veracruz Reef System, and its relation to local environmental sources. Lead was determined in four geochemical fractions: exchangeable (3.8±0.4μgg -1 ), carbonate (57.0±13.6μgg -1 ), organic matter (2.0±0.9μgg -1 ), and mineral (17.5±5.4μgg -1 ). For the mineral fraction, lead concentrations were higher in those reefs influenced by river discharge or by long-distance transport of terrigenous sediments. The bioavailable concentration of lead (range: 21.9-85.6μgg -1 ) indicates that the Veracruz Reef System is a moderately polluted area. As expected, the carbonate fraction contained the highest proportion of Pb (70%), and because the reef framework is largely made up of by biogenic carbonate sediments, hence, it is therefore the most important repository of Pb in coral reef depositional environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluating the attractiveness and effectiveness of artificial coral reefs as a recreational ecosystem service.

PubMed

Belhassen, Yaniv; Rousseau, Meghan; Tynyakov, Jenny; Shashar, Nadav

2017-12-01

Artificial reefs are increasingly being used around the globe to attract recreational divers, for both environmental and commercial reasons. This paper examines artificial coral reefs as recreational ecosystem services (RES) by evaluating their attractiveness and effectiveness and by examining divers' attitudes toward them. An online survey targeted at divers in Israel (n = 263) indicated that 35% of the dives in Eilat (a resort city on the shore of the Red Sea) take place at artificial reefs. A second study monitored divers' behavior around the Tamar artificial reef, one of the most popular submerged artificial reefs in Eilat, and juxtaposed it with divers' activities around two adjacent natural reefs. Findings show that the average diver density at the artificial reef was higher than at the two nearby natural knolls and that the artificial reef effectively diverts divers from natural knolls. A third study that examined the attitudes towards natural vs. artificial reefs found that the artificial reefs are considered more appropriate for training, but that divers feel less relaxed around them. By utilizing the RES approach as a framework, the study offers a comprehensive methodology that brings together the aesthetic, behavioral, and attitudinal aspects in terms of which artificial reefs can be evaluated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preliminary numerical simulation for shallow strata stability of coral reef in South China Sea

NASA Astrophysics Data System (ADS)

Tang, Qinqin; Zhan, Wenhuan; Zhang, Jinchang

2017-04-01

Coral reefs are the geologic material and special rock and soil, which live in shallow water of the tropic ocean and are formed through biological and geological action. Since infrastructure construction is being increasingly developed on coral reefs during recent years, it is necessary to evaluate the shallow strata stability of coral reefs in the South China Sea. The paper is to study the borehole profiles for shallow strata of coral reefs in the South China Sea, especially in the hydrodynamic marine environment?, and to establish a geological model for numerical simulation with Geo-Studio software. Five drilling holes show a six-layer shallow structure of South China Sea, including filling layer, mid-coarse sand, coral sand gravel, fine sand, limestone debris and reef limestone. The shallow coral reef profile next to lagoon is similar to "layers cake", in which the right side close to the sea is analogous to "block cake". The simulation results show that coral reef stability depends on wave loads and earthquake strength, as well as the physical properties of coral reefs themselves. The safety factor of the outer reef is greater than 10.0 in the static condition, indicating that outer reefs are less affected by the wave and earthquake. However, the safety factor next to lagoon is ranging from 0.1 to 4.9. The main reason for the variations that the strata of coral reefs close to the sea are thick. For example, the thickness of reef limestone is more than 10 m and equivalent to the block. When the thickness of inside strata is less than 10 m, they show weak engineering geological characteristics. These findings can provide useful information for coral reef constructions in future. This work was funded by National Basic Research Program of China (contract: 2013CB956104) and National Natural Science Foundation of China (contract: 41376063).

Consequences of a government-controlled agricultural price increase on fishing and the coral reef ecosystem in the republic of kiribati.

PubMed

Reddy, Sheila M W; Groves, Theodore; Nagavarapu, Sriniketh

2014-01-01

Economic development policies may have important economic and ecological consequences beyond the sector they target. Understanding these consequences is important to improving these policies and finding opportunities to align economic development with natural resource conservation. These issues are of particular interest to governments and non-governmental organizations that have new mandates to pursue multiple benefits. In this case study, we examined the direct and indirect economic and ecological effects of an increase in the government-controlled price for the primary agricultural product in the Republic of Kiribati, Central Pacific. We conducted household surveys and underwater visual surveys of the coral reef to examine how the government increase in the price of copra directly affected copra labor and indirectly affected fishing and the coral reef ecosystem. The islands of Kiribati are coral reef atolls and the majority of households participate in copra agriculture and fishing on the coral reefs. Our household survey data suggest that the 30% increase in the price of copra resulted in a 32% increase in copra labor and a 38% increase in fishing labor. Households with the largest amount of land in coconut production increased copra labor the most and households with the smallest amount of land in coconut production increased fishing the most. Our ecological data suggests that increased fishing labor may result in a 20% decrease in fish stocks and 4% decrease in coral reef-builders. We provide empirical evidence to suggest that the government increase in the copra price in Kiribati had unexpected and indirect economic and ecological consequences. In this case, the economic development policy was not in alignment with conservation. These results emphasize the importance of accounting for differences in household capital and taking a systems approach to policy design and evaluation, as advocated by sustainable livelihood and ecosystem-based management frameworks.

Consequences of a Government-Controlled Agricultural Price Increase on Fishing and the Coral Reef Ecosystem in the Republic of Kiribati

PubMed Central

Reddy, Sheila M. W.; Groves, Theodore; Nagavarapu, Sriniketh

2014-01-01

Background Economic development policies may have important economic and ecological consequences beyond the sector they target. Understanding these consequences is important to improving these policies and finding opportunities to align economic development with natural resource conservation. These issues are of particular interest to governments and non-governmental organizations that have new mandates to pursue multiple benefits. In this case study, we examined the direct and indirect economic and ecological effects of an increase in the government-controlled price for the primary agricultural product in the Republic of Kiribati, Central Pacific. Methods/Principal Findings We conducted household surveys and underwater visual surveys of the coral reef to examine how the government increase in the price of copra directly affected copra labor and indirectly affected fishing and the coral reef ecosystem. The islands of Kiribati are coral reef atolls and the majority of households participate in copra agriculture and fishing on the coral reefs. Our household survey data suggest that the 30% increase in the price of copra resulted in a 32% increase in copra labor and a 38% increase in fishing labor. Households with the largest amount of land in coconut production increased copra labor the most and households with the smallest amount of land in coconut production increased fishing the most. Our ecological data suggests that increased fishing labor may result in a 20% decrease in fish stocks and 4% decrease in coral reef-builders. Conclusions/Significance We provide empirical evidence to suggest that the government increase in the copra price in Kiribati had unexpected and indirect economic and ecological consequences. In this case, the economic development policy was not in alignment with conservation. These results emphasize the importance of accounting for differences in household capital and taking a systems approach to policy design and evaluation, as advocated by sustainable livelihood and ecosystem-based management frameworks. PMID:24820734

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

USGS Publications Warehouse

Lidz, Barbara H.

2001-01-01

Introduction In recent years, the health of the entire coral reef ecosystem that lines the outer shelf off the Florida Keys has declined markedly. In particular, loss of those coral species that are the building blocks of solid reef framework has significant negative implications for economic vitality of the region. What are the reasons for this decline? Is it due to natural change, or are human activities (recreational diving, ship groundings, farmland runoff, nutrient influx, air-borne contaminants, groundwater pollutants) a contributing factor and if so, to what extent? At risk of loss are biologic resources of the reefs, including habitats for endangered species in shoreline mangroves, productive marine and wetland nurseries, and economic fisheries. A healthy reef ecosystem builds a protective offshore barrier to catastrophic wave action and storm surges generated by tropical storms and hurricanes. In turn, a healthy reef protects the homes, marinas, and infrastructure on the Florida Keys that have been designed to capture a lucrative tourism industry. A healthy reef ecosystem also protects inland agricultural and livestock areas of South Florida whose produce and meat feed much of the United States and other parts of the world. In cooperation with the National Oceanic and Atmospheric Administration's (NOAA) National Marine Sanctuary Program, the U.S. Geological Survey (USGS) continues longterm investigations of factors that may affect Florida's reefs. One of the first steps in distinguishing between natural change and the effects of human activities, however, is to determine how coral reefs have responded to past environmental change, before the advent of man. By so doing, accurate scientific information becomes available for Marine Sanctuary management to understand natural change and thus to assess and regulate potential human impact better. The USGS studies described here evaluate the distribution (location) and historic vitality (thickness) of Holocene reefs in South Florida, relative to type of underlying bedrock morphology, and their varied natural response to rising sea level. These studies also assess movement and accumulation of sands, relative to direction of prevailing energy, and origin of the component sand grains. Geophysical data collected with highresolution sound-wave instruments that provide pictures of the sediment and bedrock are used to interpret sediment thickness. Reef thickness is determined by collecting limestone rock cores by drilling. Drill cores through reefs are used to identify the coral species that built them and to determine how reefs reacted to rising sea level. These data are supplemented by using isotope-dating techniques to derive the carbon-14 (C14) age of the corals and mangrove peat in the cores. Mangrove peat forms in very shallow water and at the shoreline but is found today buried beneath offshore reefs.

77 FR 19230 - Western Pacific Fishery Management Council; Public Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

.... Precious corals fishery and coral reef habitat status. iv. Update on Bio-Sampling Program data summary. v... precious coral fisheries. iv. Coral reef habitat status. v. Update on Bio-Sampling Program and Spearfishing... fisheries. iv. Precious corals fishery and coral reef habitat status. v. Update on Bio-Sampling Program Data...

A Synthesis and Comparison of Approaches for Quantifying Coral Reef Structure

NASA Astrophysics Data System (ADS)

Duvall, M. S.; Hench, J. L.

2016-02-01

The complex physical structures of coral reefs provide substrate for benthic organisms, surface area for material fluxes, and have been used as a predictor of reef-fish biomass and biodiversity. Coral reef topography has a first order effect on reef hydrodynamics by imposing drag forces and increasing momentum and scalar dispersion. Despite its importance, quantifying reef topography remains a challenge, as it is patchy and discontinuous while also varying over orders of magnitude in spatial scale. Previous studies have quantified reef structure using a range of 1D and 2D metrics that estimate vertical roughness, which is the departure from a flat geometric profile or surface. However, there is no general mathematical or conceptual framework by which to apply or compare these roughness metrics. While the specific calculations of different metrics vary, we propose that they can be classified into four categories based on: 1) vertical relief relative to a reference height; 2) gradients in vertical relief; 3) surface contour distance; or 4) variations in roughness with scale. We apply metrics from these four classes to idealized reef topography as well as natural reef topography data from Moorea, French Polynesia. Through the use of idealized profiles, we demonstrate the potential for reefs with different morphologies to possess the same value for some scale-dependent metrics (i.e. classes 1-3). Due to the superposition of variable-scale roughness elements in reef topography, we find that multi-scale metrics (i.e. class 4) can better characterize structural complexity by capturing surface roughness across a range of spatial scales. In particular, we provide evidence of the ability of 1D continuous wavelet transforms to detect changes in dominant roughness scales on idealized topography as well as within real reef systems.

75 FR 14571 - Western Pacific Fishery Management Council; Public Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-26

... for bottomfish, coral reef, precious coral and crustacean fisheries. Reports will be provided on... Archipelago Fishery Ecosystem Plan Annual Report Modules for bottomfish, coral reef, precious coral and..., sea turtle interaction mitigation in the American Samoa longline Fishery, DMWR coral reef ecosystem...

A deep reef in deep trouble

USGS Publications Warehouse

Menza, Charles; Kendall, M.; Rogers, C.; Miller, J.

2007-01-01

The well-documented degradation of shallower reefs which are often closer to land and more vulnerable to pollution, sewage and other human-related stressors has led to the suggestion that deeper, more remote offshore reefs could possibly serve as sources of coral and fish larvae to replenish the shallower reefs. Yet, the distribution, status, and ecological roles of deep (>30 m) Caribbean reefs are not well known. In this report, an observation of a deep reef which has undergone a recent extensive loss of coral cover is presented. In stark contrast to the typical pattern of coral loss in shallow reefs, the deeper corals were most affected. This report is the first description of such a pattern of coral loss on a deep reef.

The Ecological Role of Sharks on Coral Reefs.

PubMed

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

2016-05-01

Sharks are considered the apex predator of coral reefs, but the consequences of their global depletion are uncertain. Here we explore the ecological roles of sharks on coral reefs and, conversely, the importance of reefs for sharks. We find that most reef-associated shark species do not act as apex predators but instead function as mesopredators along with a diverse group of reef fish. While sharks perform important direct and indirect ecological roles, the evidence to support hypothesised shark-driven trophic cascades that benefit corals is weak and equivocal. Coral reefs provide some functional benefits to sharks, but sharks do not appear to favour healthier reef environments. Restoring populations of sharks is important and can yet deliver ecological surprise. Copyright © 2016 Elsevier Ltd. All rights reserved.

50 CFR 665.124 - Permits and fees.

Code of Federal Regulations, 2014 CFR

2014-10-01

... retaining American Samoa coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) American Samoa coral reef ecosystem MUS in low-use MPAs as defined in § 665.99; (ii) American Samoa Potentially Harvested Coral Reef Taxa in the coral reef ecosystem...

50 CFR 665.124 - Permits and fees.

Code of Federal Regulations, 2013 CFR

2013-10-01

... retaining American Samoa coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) American Samoa coral reef ecosystem MUS in low-use MPAs as defined in § 665.99; (ii) American Samoa Potentially Harvested Coral Reef Taxa in the coral reef ecosystem...

50 CFR 665.424 - Permits and fees.

Code of Federal Regulations, 2012 CFR

2012-10-01

... retaining Mariana coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Mariana coral reef ecosystem MUS in low-use MPAs as defined in § 665.399; (ii) Mariana Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area...

50 CFR 665.124 - Permits and fees.

Code of Federal Regulations, 2012 CFR

2012-10-01

... retaining American Samoa coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) American Samoa coral reef ecosystem MUS in low-use MPAs as defined in § 665.99; (ii) American Samoa Potentially Harvested Coral Reef Taxa in the coral reef ecosystem...

50 CFR 665.424 - Permits and fees.

Code of Federal Regulations, 2014 CFR

2014-10-01

... retaining Mariana coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Mariana coral reef ecosystem MUS in low-use MPAs as defined in § 665.399; (ii) Mariana Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area...

50 CFR 665.424 - Permits and fees.

Code of Federal Regulations, 2013 CFR

2013-10-01

... retaining Mariana coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Mariana coral reef ecosystem MUS in low-use MPAs as defined in § 665.399; (ii) Mariana Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area...

50 CFR 665.124 - Permits and fees.

Code of Federal Regulations, 2011 CFR

2011-10-01

... retaining American Samoa coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) American Samoa coral reef ecosystem MUS in low-use MPAs as defined in § 665.99; (ii) American Samoa Potentially Harvested Coral Reef Taxa in the coral reef ecosystem...

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

ERIC Educational Resources Information Center

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

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

50 CFR 665.424 - Permits and fees.

Code of Federal Regulations, 2010 CFR

2010-10-01

... retaining Mariana coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Mariana coral reef ecosystem MUS in low-use MPAs as defined in § 665.399; (ii) Mariana Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area...

50 CFR 665.424 - Permits and fees.

Code of Federal Regulations, 2011 CFR

2011-10-01

... retaining Mariana coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Mariana coral reef ecosystem MUS in low-use MPAs as defined in § 665.399; (ii) Mariana Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area...

78 FR 16296 - Record of Decision for the Coral Reef Restoration Plan, Biscayne National Park, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-14

...] Record of Decision for the Coral Reef Restoration Plan, Biscayne National Park, FL AGENCY: National Park... Record of Decision (ROD) for the Coral Reef Restoration Plan (Plan) for Biscayne National Park, Florida... Biscayne National Park, causing injuries to submerged resources. The goal of coral reef restoration actions...

50 CFR 665.124 - Permits and fees.

Code of Federal Regulations, 2010 CFR

2010-10-01

... retaining American Samoa coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) American Samoa coral reef ecosystem MUS in low-use MPAs as defined in § 665.99; (ii) American Samoa Potentially Harvested Coral Reef Taxa in the coral reef ecosystem...

Mass coral bleaching in 2010 in the southern Caribbean.

PubMed

Alemu I, Jahson Berhane; Clement, Ysharda

2014-01-01

Ocean temperatures are increasing globally and the Caribbean is no exception. An extreme ocean warming event in 2010 placed Tobago's coral reefs under severe stress resulting in widespread coral bleaching and threatening the livelihoods that rely on them. The bleaching response of four reef building taxa was monitored over a six month period across three major reefs systems in Tobago. By identifying taxa resilient to bleaching we propose to assist local coral reef managers in the decision making process to cope with mass bleaching events. The bleaching signal (length of exposure to high ocean temperatures) varied widely between the Atlantic and Caribbean reefs, but regardless of this variation most taxa bleached. Colpophyllia natans, Montastraea faveolata and Siderastrea siderea were considered the most bleaching vulnerable taxa. Interestingly, reefs with the highest coral cover showed the greatest decline reef building taxa, and conversely, reefs with the lowest coral cover showed the most bleaching but lowest change in coral cover with little algal overgrowth post-bleaching.

Mass Coral Bleaching in 2010 in the Southern Caribbean

PubMed Central

Alemu I, Jahson Berhane; Clement, Ysharda

2014-01-01

Ocean temperatures are increasing globally and the Caribbean is no exception. An extreme ocean warming event in 2010 placed Tobago's coral reefs under severe stress resulting in widespread coral bleaching and threatening the livelihoods that rely on them. The bleaching response of four reef building taxa was monitored over a six month period across three major reefs systems in Tobago. By identifying taxa resilient to bleaching we propose to assist local coral reef managers in the decision making process to cope with mass bleaching events. The bleaching signal (length of exposure to high ocean temperatures) varied widely between the Atlantic and Caribbean reefs, but regardless of this variation most taxa bleached. Colpophyllia natans, Montastraea faveolata and Siderastrea siderea were considered the most bleaching vulnerable taxa. Interestingly, reefs with the highest coral cover showed the greatest decline reef building taxa, and conversely, reefs with the lowest coral cover showed the most bleaching but lowest change in coral cover with little algal overgrowth post-bleaching. PMID:24400078

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

NASA Astrophysics Data System (ADS)

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

2015-02-01

Predicted increases in seawater temperatures accelerate coral reef decline due to mortality by heat-driven coral bleaching. Alteration of the natural nutrient environment of reef corals reduces tolerance of corals to heat and light stress and thus will exacerbate impacts of global warming on reefs. Still, many reefs demonstrate remarkable regeneration from past stress events. This paper investigates the effects of sea surface temperature (SST) and water column productivity on recovery of coral reefs. In 71 Indo-Pacific sites, coral cover changes over the past 1-3 decades correlated negative-exponentially with mean SST, chlorophyll a, and SST rise. At six monitoring sites (Persian/Arabian Gulf, Red Sea, northern and southern Galápagos, Easter Island, Panama), over half of all corals were <31 years, implying that measured environmental variables indeed shaped populations and community. An Indo-Pacific-wide model suggests reefs in the northwest and central Indian Ocean, as well as the central west Pacific, are at highest risk of degradation, and those at high latitudes the least. The model pinpoints regions where coral reefs presently have the best chances for survival. However, reefs best buffered against temperature and nutrient effects are those that current studies suggest to be most at peril from future ocean acidification.

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

PubMed

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

2015-02-05

Predicted increases in seawater temperatures accelerate coral reef decline due to mortality by heat-driven coral bleaching. Alteration of the natural nutrient environment of reef corals reduces tolerance of corals to heat and light stress and thus will exacerbate impacts of global warming on reefs. Still, many reefs demonstrate remarkable regeneration from past stress events. This paper investigates the effects of sea surface temperature (SST) and water column productivity on recovery of coral reefs. In 71 Indo-Pacific sites, coral cover changes over the past 1-3 decades correlated negative-exponentially with mean SST, chlorophyll a, and SST rise. At six monitoring sites (Persian/Arabian Gulf, Red Sea, northern and southern Galápagos, Easter Island, Panama), over half of all corals were <31 years, implying that measured environmental variables indeed shaped populations and community. An Indo-Pacific-wide model suggests reefs in the northwest and central Indian Ocean, as well as the central west Pacific, are at highest risk of degradation, and those at high latitudes the least. The model pinpoints regions where coral reefs presently have the best chances for survival. However, reefs best buffered against temperature and nutrient effects are those that current studies suggest to be most at peril from future ocean acidification.

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

NASA Technical Reports Server (NTRS)

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

2008-01-01

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

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

PubMed

Wild, Christian; Huettel, Markus; Klueter, Anke; Kremb, Stephan G; Rasheed, Mohammed Y M; Jørgensen, Bo B

2004-03-04

Zooxanthellae, endosymbiotic algae of reef-building corals, substantially contribute to the high gross primary production of coral reefs, but corals exude up to half of the carbon assimilated by their zooxanthellae as mucus. Here we show that released coral mucus efficiently traps organic matter from the water column and rapidly carries energy and nutrients to the reef lagoon sediment, which acts as a biocatalytic mineralizing filter. In the Great Barrier Reef, the dominant genus of hard corals, Acropora, exudes up to 4.8 litres of mucus per square metre of reef area per day. Between 56% and 80% of this mucus dissolves in the reef water, which is filtered through the lagoon sands. Here, coral mucus is degraded at a turnover rate of at least 7% per hour. Detached undissolved mucus traps suspended particles, increasing its initial organic carbon and nitrogen content by three orders of magnitude within 2 h. Tidal currents concentrate these mucus aggregates into the lagoon, where they rapidly settle. Coral mucus provides light energy harvested by the zooxanthellae and trapped particles to the heterotrophic reef community, thereby establishing a recycling loop that supports benthic life, while reducing loss of energy and nutrients from the reef ecosystem.

Small change, big difference: Sea surface temperature distributions for tropical coral reef ecosystems, 1950-2011

NASA Astrophysics Data System (ADS)

Lough, J. M.

2012-09-01

Changes in tropical sea surface temperature (SST) are examined over the period 1950-2011 during which global average temperature warmed by 0.4°C. Average tropical SST is warming about 70% of the global average rate. Spatially, significant warming between the two time periods, 1950-1980 and 1981-2011, has occurred across 65% of the tropical oceans. Coral reef ecosystems occupy 10% of the tropical oceans, typically in regions of warmer (+1.8°C) and less variable SST (80% of months within 3.3°C range) compared to non-reef areas (80% of months within 7.0°C range). SST is a primary controlling factor of coral reef distribution and coral reef organisms have already shown their sensitivity to the relatively small amount of warming observed so far through, for example, more frequent coral bleaching events and outbreaks of coral disease. Experimental evidence is also emerging of possible thermal thresholds in the range 30°C-32°C for some physiological processes of coral reef organisms. Relatively small changes in SST have already resulted in quite large differences in SST distribution with a maximum ‘hot spot’ of change in the near-equatorial Indo-Pacific which encompasses both the Indo-Pacific warm pools and the center of coral reef biodiversity. Identification of this hot spot of SST change is not new but this study highlights its significance with respect to tropical coral reef ecosystems. Given the modest amount of warming to date, changes in SST distribution are of particular concern for coral reefs given additional local anthropogenic stresses on many reefs and ongoing ocean acidification likely to increasingly compromise coral reef processes.

Coral reefs promote the evolution of morphological diversity and ecological novelty in labrid fishes.

PubMed

Price, S A; Holzman, R; Near, T J; Wainwright, P C

2011-05-01

Although coral reefs are renowned biodiversity hotspots it is not known whether they also promote the evolution of exceptional ecomorphological diversity. We investigated this question by analysing a large functional morphological dataset of trophic characters within Labridae, a highly diverse group of fishes. Using an analysis that accounts for species relationships, the time available for diversification and model uncertainty we show that coral reef species have evolved functional morphological diversity twice as fast as non-reef species. In addition, coral reef species occupy 68.6% more trophic morphospace than non-reef species. Our results suggest that coral reef habitats promote the evolution of both trophic novelty and morphological diversity within fishes. Thus, the preservation of coral reefs is necessary, not only to safeguard current biological diversity but also to conserve the underlying mechanisms that can produce functional diversity in future. © 2011 Blackwell Publishing Ltd/CNRS.

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

EPA Pesticide Factsheets

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

Skeletal Strength and Skeletogenetic Mechanisms Over Phanerozoic Time

NASA Astrophysics Data System (ADS)

Constantz, B. R.

2004-12-01

Mineralized skeletons have a remarkable range of mechanical properties with respect to strength and durability. Measurements of skeletal mechanical properties show that taxonomic groups with relatively simple, `physiochemically-dominated' modes of mineralization possess skeletal strengths and durabilities that are among the lowest of any known mineralized skeletons. Organisms with relatively sophisticated, `biologically-dominated' modes of mineralization have mechanical properties among the highest values known for any materials. These extraordinarily strong and durable skeletal materials are found in mollusks, echinoderms, vertebrates, and arthropods, which are groups with primarily mobile ecological habits. These skeletons are frequently lightweight, non-massive skeletons with little phenotypic variation. By contrast, dominant reef framework builders and reef sediment formers, with physiochemically-dominated modes of mineralization, have non-mobile ecological habits and construct massive, phenotypically plastic skeletons, possessing extremely poor mechanical properties. Endolithic organisms that further degrade the mechanical properties of the mineralized skeletons of reef builders frequently ravage their massive skeletons. As a result, the skeletons of these groups commonly fragment, and play a central role in reef establishment and maintenance, as they are incorporated in reefal, wave-resistant carbonate buildups. Scleractinian corals have a physiochemically-dominated mode of mineralization and are the dominant modern reef framework builders. Mechanical properties of modern aragonitic scleractinian coral skeletons, tested alive, demonstrate skeletal strengths that are orders of magnitude lower than those seen in mollusks, echinoderms, vertebrates, and arthropods. Rudist bivalves, the dominant reef framework-building group of the Cretaceous, show prolific, massive, highly variable, calcific skeletal elements with structures similar to some reef-forming modern, non-mobile mollusks and the skeletons of other organisms with physiochemically-dominated modes of mineralization. Many aspects of the ecological habits of reef-framework building scleractinians and rudsits are similar, including relatively high skeletal growth rates, which produce massive skeletons and wave-resistant structures with entrapped bioclastic sediments. The principal adaptive role of mineralization in reef framework building groups appears to be the rapid production of massive, brittle, wave-resistant mineralized skeletons. The physiochemically-dominated mode of mineralization of these reef framework builders appears to have made them susceptible to secular variations in Phanerozoic seawater during `calcite' and `aragonite' seas, favoring scleractinians in aragonite seas and rudists during the Cretaceous calcite episode. By contrast, most mobile mollusks, echinoderms, vertebrates, and arthropods appear relatively unaffected by secular variations in seawater chemistry over the Phanerozoic

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

NASA Astrophysics Data System (ADS)

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

2003-12-01

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

76 FR 16618 - Western Pacific Fishery Management Council; Public Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-24

... Programs and Research Projects A. Coral Reef Fisheries B. Crustacean Fisheries C. Precious Coral Fisheries... Offshore Aquaculture 7. Coral Reef Funded Projects A. Kona Crab Stock Assessment B. Black Coral Mapping C. Deepwater Chorusing Phenomenon D. Report on Tournament Sampling E. Upcoming Coral Reef Projects Schedule and...

Ocean acidification causes bleaching and productivity loss in coral reef builders

PubMed Central

Anthony, K. R. N.; Kline, D. I.; Diaz-Pulido, G.; Dove, S.; Hoegh-Guldberg, O.

2008-01-01

Ocean acidification represents a key threat to coral reefs by reducing the calcification rate of framework builders. In addition, acidification is likely to affect the relationship between corals and their symbiotic dinoflagellates and the productivity of this association. However, little is known about how acidification impacts on the physiology of reef builders and how acidification interacts with warming. Here, we report on an 8-week study that compared bleaching, productivity, and calcification responses of crustose coralline algae (CCA) and branching (Acropora) and massive (Porites) coral species in response to acidification and warming. Using a 30-tank experimental system, we manipulated CO2 levels to simulate doubling and three- to fourfold increases [Intergovernmental Panel on Climate Change (IPCC) projection categories IV and VI] relative to present-day levels under cool and warm scenarios. Results indicated that high CO2 is a bleaching agent for corals and CCA under high irradiance, acting synergistically with warming to lower thermal bleaching thresholds. We propose that CO2 induces bleaching via its impact on photoprotective mechanisms of the photosystems. Overall, acidification impacted more strongly on bleaching and productivity than on calcification. Interestingly, the intermediate, warm CO2 scenario led to a 30% increase in productivity in Acropora, whereas high CO2 lead to zero productivity in both corals. CCA were most sensitive to acidification, with high CO2 leading to negative productivity and high rates of net dissolution. Our findings suggest that sensitive reef-building species such as CCA may be pushed beyond their thresholds for growth and survival within the next few decades whereas corals will show delayed and mixed responses. PMID:18988740

Forecasted coral reef decline in marine biodiversity hotspots under climate change.

PubMed

Descombes, Patrice; Wisz, Mary S; Leprieur, Fabien; Parravicini, Valerianio; Heine, Christian; Olsen, Steffen M; Swingedouw, Didier; Kulbicki, Michel; Mouillot, David; Pellissier, Loïc

2015-01-21

Coral bleaching events threaten coral reef habitats globally and cause severe declines of local biodiversity and productivity. Related to high sea surface temperatures (SST), bleaching events are expected to increase as a consequence of future global warming. However, response to climate change is still uncertain as future low-latitude climatic conditions have no present-day analogue. Sea surface temperatures during the Eocene epoch were warmer than forecasted changes for the coming century, and distributions of corals during the Eocene may help to inform models forecasting the future of coral reefs. We coupled contemporary and Eocene coral occurrences with information on their respective climatic conditions to model the thermal niche of coral reefs and its potential response to projected climate change. We found that under the RCP8.5 climate change scenario, the global suitability for coral reefs may increase up to 16% by 2100, mostly due to improved suitability of higher latitudes. In contrast, in its current range, coral reef suitability may decrease up to 46% by 2100. Reduction in thermal suitability will be most severe in biodiversity hotspots, especially in the Indo-Australian Archipelago. Our results suggest that many contemporary hotspots for coral reefs, including those that have been refugia in the past, spatially mismatch with future suitable areas for coral reefs posing challenges to conservation actions under climate change. © 2015 John Wiley & Sons Ltd.

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

NASA Astrophysics Data System (ADS)

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

2017-06-01

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

Closing the circle: is it feasible to rehabilitate reefs with sexually propagated corals?

NASA Astrophysics Data System (ADS)

Guest, J. R.; Baria, M. V.; Gomez, E. D.; Heyward, A. J.; Edwards, A. J.

2014-03-01

Sexual propagation of corals specifically for reef rehabilitation remains largely experimental. In this study, we refined low technology culture and transplantation approaches and assessed the role of colony size and age, at time of transfer from nursery to reef, on subsequent survival. Larvae from Acropora millepora were reared from gametes and settled on engineered substrates, called coral plug-ins, that were designed to simplify transplantation to areas of degraded reef. Plug-ins, with laboratory spawned and settled coral recruits attached, were maintained in nurseries until they were at least 7 months old before being transplanted to replicate coral limestone outcrops within a marine protected area until they were 31 months old. Survival rates of transplanted corals that remained at the protected in situ nursery the longest were 3.9-5.6 times higher than corals transplanted to the reef earlier, demonstrating that an intermediate ocean nursery stage is critical in the sexual propagation of corals for reef rehabilitation. 3 years post-settlement, colonies were reproductively mature, making this one of few published studies to date to rear a broadcasting scleractinian from eggs to spawning adults. While our data show that it is technically feasible to transplant sexually propagated corals and rear them until maturity, producing a single 2.5-year-old coral on the reef cost at least US60. `What if' scenarios indicate that the cost per transplantable coral could be reduced by almost 80 %, nevertheless, it is likely that the high cost per coral using sexual propagation methods would constrain delivery of new corals to relatively small scales in many countries with coral reefs.

50 CFR 665.224 - Permits and fees.

Code of Federal Regulations, 2012 CFR

2012-10-01

... retaining Hawaii coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Hawaii coral reef ecosystem MUS in low-use MPAs as defined in § 665.199; (ii) Hawaii Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area; or (iii...

50 CFR 665.224 - Permits and fees.

Code of Federal Regulations, 2014 CFR

2014-10-01

... retaining Hawaii coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Hawaii coral reef ecosystem MUS in low-use MPAs as defined in § 665.199; (ii) Hawaii Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area; or (iii...

50 CFR 665.224 - Permits and fees.

Code of Federal Regulations, 2013 CFR

2013-10-01

... retaining Hawaii coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Hawaii coral reef ecosystem MUS in low-use MPAs as defined in § 665.199; (ii) Hawaii Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area; or (iii...

76 FR 52318 - U.S. Coral Reef Task Force Public Meeting and Public Comment

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-22

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration U.S. Coral Reef Task Force... of the U.S. Coral Reef Task Force. The meeting will be held in Ft. Lauderdale, Florida. This meeting, the 26th bi-annual meeting of the U.S. Coral Reef Task Force, provides a forum for coordinated...

76 FR 59373 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Generic Annual Catch Limits...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-26

... Fishery Management Plans (FMPs) for Reef Fish Resources, Red Drum, Shrimp, and Coral and Coral Reefs for... Coral and Coral Reefs FMP. The majority of harvest of octocorals occurs in waters under the jurisdiction... commercial and recreational sectors within the reef fish fishery in the Gulf. Finally, the Generic ACL...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-05

...-DS61200000] U.S. Coral Reef Task Force Public Meeting and Public Comment AGENCY: Fish and Wildlife Service... Wildlife Service (Service), announce a public meeting of the U.S. Coral Reef Task Force (USCRTF) and a... strengthen U.S. government actions to better preserve and protect coral reef ecosystems. The Departments of...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-10

.... Coral Reef Task Force Public Meeting and Public Comment AGENCY: Fish and Wildlife Service, Interior... Service (Service), announce a public business meeting of the U.S. Coral Reef Task Force (USCRTF) [email protected] ); or Liza Johnson, U.S. Coral Reef Task Force Department of the Interior Liaison, U.S...

50 CFR 665.224 - Permits and fees.

Code of Federal Regulations, 2010 CFR

2010-10-01

... retaining Hawaii coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Hawaii coral reef ecosystem MUS in low-use MPAs as defined in § 665.199; (ii) Hawaii Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area; or (iii...

50 CFR 665.224 - Permits and fees.

Code of Federal Regulations, 2011 CFR

2011-10-01

... retaining Hawaii coral reef ecosystem MUS must have a special permit if they, or a vessel which they operate, is used to fish for any: (i) Hawaii coral reef ecosystem MUS in low-use MPAs as defined in § 665.199; (ii) Hawaii Potentially Harvested Coral Reef Taxa in the coral reef ecosystem management area; or (iii...

Workshop on Biological Integrity of Coral Reefs August 21-22, 2012, Caribbean Coral Reef Institute, Isla Magueyes, La Parguera, Puerto Rico.

EPA Science Inventory

This report summarizes an EPA-sponsored workshop on coral reef biological integrity held at the Caribbean Coral Reef Institute in La Parguera, Puerto Rico on August 21-22, 2012. The goals of this workshop were to:• Identify key qualitative and quantitative ecological characterist...

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.

A New Perspective: Assessing the Spatial Distribution of Coral Bleaching with Unmanned Low Altitude Remote Sensing Systems

NASA Astrophysics Data System (ADS)

Levy, J.; Franklin, E. C.; Hunter, C. L.

2016-12-01

Coral reefs are biodiversity hotspots that are vital to the function of global economic and biological processes. Coral bleaching is a significant contributor to the global decline of reefs and can impact an expansive reef area over short timescales. In order to understand the dynamics of coral bleaching and how these stress events impact reef ecosystems, it is important to conduct rapid bleaching surveys at functionally important spatial scales. Due to the inherent heterogeneity, size, and in some cases, remoteness of coral reefs, it is difficult to routinely monitor coral bleaching dynamics before, during, and after bleaching. Additionally, current in situ survey methods only collect snippets of discrete reef data over small reef areas, which are unable to accurately represent the reef as a whole. We present a new technique using small unmanned aerial systems (sUAS) as cost effective, efficient monitoring tools that target small to intermediate-scale reef dynamics to understand the spatial distribution of bleached coral colonies during the 2015 bleaching event on patch reefs in Kaneohe Bay, Oahu. Overlapping low altitude aerial images were collected at four reefs during the bleaching period and processed using Structure-from-Motion techniques to produce georeferenced and spatially accurate orthomosaics of complete reef areas. Mosaics were analyzed using manual and heuristic neural network classification schemes to identify comprehensive populations of bleached and live coral on each patch reef. We found that bleached colonies had random and clumped distributions on patch reefs in Kaneohe Bay depending on local environmental conditions. Our work demonstrates that sUAS provide a low cost, efficient platform that can rapidly and repeatedly collect high-resolution imagery (1 cm/pixel) and map large areas of shallow reef ecosystems (5 hectares). This study proves the feasibility of utilizing sUAS as a tool to collect spatially rich reef data that will provide reef scientists a new perspective on meso-scale coral reef dynamics. We envision that similar low altitude aerial surveys will be incorporated as a standard component of shallow-water reef studies, especially on reefs too dangerous or remote for in situ surveys.

Possible Evidence of Multiple Sea Level Oscillations in the Seychelles During the Last Interglacial

NASA Astrophysics Data System (ADS)

Dutton, A. L.; Vyverberg, K.; Webster, J.; Dechnik, B.; Zwartz, D.; Lambeck, K.

2013-12-01

In search of a eustatic sea level signal on glacial-interglacial timescales, the Seychelles ranks as one of the best places on the planet to study. Owing to its far-field location with respect to the former margins of Northern Hemisphere ice sheets, glacio-hydro-isostatic models predict that relative sea level in the Seychelles should lie within a few meters of the globally averaged eustatic signal during interglacial periods. We have surveyed and dated fossil coral reefs from the last interglacial period to determine the magnitude of peak sea level and to assess sedimentologic evidence of potential sea level oscillations. Numerous outcrops we studied in detail exhibit a stratigraphic sequence comprised of in situ coralgal framework at the base, capped by thick coralline algae crusts, and overlain by coral rubble deposits. We also observed a succession of three stacked coralgal reefs within a single outcrop, separated by hardgrounds that have been bored by molluscs. In general, the succession within each reef unit consists of interlayered corals and crusts of coralline algae-vermetid gastropods-encrusting foraminifera. The lower two reef units are capped by a well-cemented 5 to 10 cm thick carbonate mud layer that is heavily bored by molluscs. These two surfaces may represent exposure surfaces during brief sea level oscillations, where sea level fell and exposed the top of the reef sequence, which was subsequently bored when sea level rose again and reef growth resumed. The elevations of the corals in each reef unit provide minimum elevations of sea level during each of the three pulses of sea level highstands during the last interglacial period. Significantly, since many of these corals are capped by thick coralline algae layers that contain vermetid gastropods and encrusting foraminifera that are indicative of the intertidal zone, there is strong evidence that these corals grew in extremely shallow water, providing a robust indication of sea level position. These observations ostensibly support the notion that the last interglacial period was characterized by ice sheet instability, causing multiple sea level oscillations.

Are coral reefs victims of their own past success?

PubMed

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

2016-04-01

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

Effect of Phase Shift from Corals to Zoantharia on Reef Fish Assemblages

PubMed Central

Cruz, Igor C. S.; Loiola, Miguel; Albuquerque, Tiago; Reis, Rodrigo; de Anchieta C. C. Nunes, José; Reimer, James D.; Mizuyama, Masaru; Kikuchi, Ruy K. P.; Creed, Joel C.

2015-01-01

Consequences of reef phase shifts on fish communities remain poorly understood. Studies on the causes, effects and consequences of phase shifts on reef fish communities have only been considered for coral-to-macroalgae shifts. Therefore, there is a large information gap regarding the consequences of novel phase shifts and how these kinds of phase shifts impact on fish assemblages. This study aimed to compare the fish assemblages on reefs under normal conditions (relatively high cover of corals) to those which have shifted to a dominance of the zoantharian Palythoa cf. variabilis on coral reefs in Todos os Santos Bay (TSB), Brazilian eastern coast. We examined eight reefs, where we estimated cover of corals and P. cf. variabilis and coral reef fish richness, abundance and body size. Fish richness differed significantly between normal reefs (48 species) and phase-shift reefs (38 species), a 20% reduction in species. However there was no difference in fish abundance between normal and phase shift reefs. One fish species, Chaetodon striatus, was significantly less abundant on normal reefs. The differences in fish assemblages between different reef phases was due to differences in trophic groups of fish; on normal reefs carnivorous fishes were more abundant, while on phase shift reefs mobile invertivores dominated. PMID:25629532

Calcification, Storm Damage and Population Resilience of Tabular Corals under Climate Change

PubMed Central

Madin, Joshua S.; Hughes, Terry P.; Connolly, Sean R.

2012-01-01

Two facets of climate change–increased tropical storm intensity and ocean acidification–are expected to detrimentally affect reef-building organisms by increasing their mortality rates and decreasing their calcification rates. Our current understanding of these effects is largely based on individual organisms’ short-term responses to experimental manipulations. However, predicting the ecologically-relevant effects of climate change requires understanding the long-term demographic implications of these organism-level responses. In this study, we investigate how storm intensity and calcification rate interact to affect population dynamics of the table coral Acropora hyacinthus, a dominant and geographically widespread ecosystem engineer on wave-exposed Indo-Pacific reefs. We develop a mechanistic framework based on the responses of individual-level demographic rates to changes in the physical and chemical environment, using a size-structured population model that enables us to rigorously incorporate uncertainty. We find that table coral populations are vulnerable to future collapse, placing in jeopardy many other reef organisms that are dependent upon them for shelter and food. Resistance to collapse is largely insensitive to predicted changes in storm intensity, but is highly dependent on the extent to which calcification influences both the mechanical properties of reef substrate and the colony-level trade-off between growth rate and skeletal strength. This study provides the first rigorous quantitative accounting of the demographic implications of the effects of ocean acidification and changes in storm intensity, and provides a template for further studies of climate-induced shifts in ecosystems, including coral reefs. PMID:23056379

Towards an integrated network of coral immune mechanisms

PubMed Central

Palmer, C. V.; Traylor-Knowles, N.

2012-01-01

Reef-building corals form bio-diverse marine ecosystems of high societal and economic value, but are in significant decline globally due, in part, to rapid climatic changes. As immunity is a predictor of coral disease and thermal stress susceptibility, a comprehensive understanding of this new field will likely provide a mechanistic explanation for ecological-scale trends in reef declines. Recently, several strides within coral immunology document defence mechanisms that are consistent with those of both invertebrates and vertebrates, and which span the recognition, signalling and effector response phases of innate immunity. However, many of these studies remain discrete and unincorporated into the wider fields of invertebrate immunology or coral biology. To encourage the rapid development of coral immunology, we comprehensively synthesize the current understanding of the field in the context of general invertebrate immunology, and highlight fundamental gaps in our knowledge. We propose a framework for future research that we hope will stimulate directional studies in this emerging field and lead to the elucidation of an integrated network of coral immune mechanisms. Once established, we are optimistic that coral immunology can be effectively applied to pertinent ecological questions, improve current prediction tools and aid conservation efforts. PMID:22896649

Global inequities between polluters and the polluted: climate change impacts on coral reefs.

PubMed

Wolff, Nicholas H; Donner, Simon D; Cao, Long; Iglesias-Prieto, Roberto; Sale, Peter F; Mumby, Peter J

2015-11-01

For many ecosystem services, it remains uncertain whether the impacts of climate change will be mostly negative or positive and how these changes will be geographically distributed. These unknowns hamper the identification of regional winners and losers, which can influence debate over climate policy. Here, we use coral reefs to explore the spatial variability of climate stress by modelling the ecological impacts of rising sea temperatures and ocean acidification, two important coral stressors associated with increasing greenhouse gas (GHG) emissions. We then combine these results with national per capita emissions to quantify inequities arising from the distribution of cause (CO2 emissions) and effect (stress upon reefs) among coral reef countries. We find pollution and coral stress are spatially decoupled, creating substantial inequity of impacts as a function of emissions. We then consider the implications of such inequity for international climate policy. Targets for GHG reductions are likely to be tied to a country's emissions. Yet within a given level of GHG emissions, our analysis reveals that some countries experience relatively high levels of impact and will likely experience greater financial cost in terms of lost ecosystem productivity and more extensive adaptation measures. We suggest countries so disadvantaged be given access to international adaptation funds proportionate with impacts to their ecosystem. We raise the idea that funds could be more equitably allocated by formally including a metric of equity within a vulnerability framework. © 2015 John Wiley & Sons Ltd.

Impact of warming events on reef-scale temperature variability as captured in two Little Cayman coral Sr/Ca records

NASA Astrophysics Data System (ADS)

von Reumont, J.; Hetzinger, S.; Garbe-Schönberg, D.; Manfrino, C.; Dullo, W.-Chr.

2016-03-01

The rising temperature of the world's oceans is affecting coral reef ecosystems by increasing the frequency and severity of bleaching and mortality events. The susceptibility of corals to temperature stress varies on local and regional scales. Insights into potential controlling parameters are hampered by a lack of long term in situ data in most coral reef environments and sea surface temperature (SST) products often do not resolve reef-scale variations. Here we use 42 years (1970-2012) of coral Sr/Ca data to reconstruct seasonal- to decadal-scale SST variations in two adjacent but distinct reef environments at Little Cayman, Cayman Islands. Our results indicate that two massive Diploria strigosa corals growing in the lagoon and in the fore reef responded differently to past warming events. Coral Sr/Ca data from the shallow lagoon successfully record high summer temperatures confirmed by in situ observations (>33°C). Surprisingly, coral Sr/Ca from the deeper fore reef is strongly affected by thermal stress events, although seasonal temperature extremes and mean SSTs at this site are reduced compared to the lagoon. The shallow lagoon coral showed decadal variations in Sr/Ca, supposedly related to the modulation of lagoonal temperature through varying tidal water exchange, influenced by the 18.6 year lunar nodal cycle. Our results show that reef-scale SST variability can be much larger than suggested by satellite SST measurements. Thus, using coral SST proxy records from different reef zones combined with in situ observations will improve conservation programs that are developed to monitor and predict potential thermal stress on coral reefs.

Coral Calcification Across a Natural Gradient in Ocean Acidification

NASA Astrophysics Data System (ADS)

Cohen, A. L.; Brainard, R. E.; Young, C.; Shamberger, K. E.; McCorkle, D. C.; Feely, R. A.; Mcleod, E.; Cantin, N.; Rose, K.; Lohmann, G. P.

2011-12-01

Much of our understanding of the impact of ocean acidification on coral calcification comes from laboratory manipulation experiments in which corals are reared under a range of seawater pH and aragonite saturation states (μar) equivalent to those projected for the next hundred years. In general, experiments show a consistently negative impact of acidification on coral calcification, leading to predictions of mass coral reef extinctions by dissolution as natural rates of carbonate erosion exceed the rates at which corals and other reef calcifiers can replace it. The tropical oceans provide a natural laboratory within which to test hypotheses about the longer term impact and adaptive potential of corals to acidification of the reef environment. Here we report results of a study in which 3-D CT scan and imaging techniques were used to quantify annual rates of calcification by conspecifics at 12 reefs sites spanning a natural gradient in ocean acidification. In situ μar calculated from alkalinity and DIC measurements of reef seawater ranged from less than 2.7 on an eastern Pacific Reef to greater than 4.0 in the central Red Sea. No correlation between μar and calcification was observed across this range. Corals living on low μar reefs appear to be calcifying as fast, sometimes faster than conspecifics living on high μar reefs. We used total lipid and tissue thickness to index the energetic status of colonies collected at each of our study sites. Our results support the hypothesis that energetics plays a key role in the coral calcification response to ocean acidification. Indeed, the true impact of acidification on coral reefs will likely be felt as temperatures rise and the ocean becomes more stratified, depleting coral energetic reserves through bleaching and reduced nutrient delivery to oceanic reefs.

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

PubMed

Lough, Janice M

2008-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2014-03-01

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

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

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-06

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service U.S. Coral Reef Task Force Public Meeting and... (Service), announce a public meeting of the U.S. Coral Reef Task Force (USCRTF) and a request for written.... Coral Reef Task Force Department of the Interior Liaison, U.S. Department of the Interior, MS-3530-MIB...

Ocean acidification accelerates dissolution of experimental coral reef communities

NASA Astrophysics Data System (ADS)

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

2015-01-01

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

Ocean acidification accelerates dissolution of experimental coral reef communities

NASA Astrophysics Data System (ADS)

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

2014-08-01

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

Synergistic impacts of global warming on the resilience of coral reefs

PubMed Central

Bozec, Yves-Marie; Mumby, Peter J.

2015-01-01

Recent epizootics have removed important functional species from Caribbean coral reefs and left communities vulnerable to alternative attractors. Global warming will impact reefs further through two mechanisms. A chronic mechanism reduces coral calcification, which can result in depressed somatic growth. An acute mechanism, coral bleaching, causes extreme mortality when sea temperatures become anomalously high. We ask how these two mechanisms interact in driving future reef state (coral cover) and resilience (the probability of a reef remaining within a coral attractor). We find that acute mechanisms have the greatest impact overall, but the nature of the interaction with chronic stress depends on the metric considered. Chronic and acute stress act additively on reef state but form a strong synergy when influencing resilience by intensifying a regime shift. Chronic stress increases the size of the algal basin of attraction (at the expense of the coral basin), whereas coral bleaching pushes the system closer to the algal attractor. Resilience can change faster—and earlier—than a change in reef state. Therefore, we caution against basing management solely on measures of reef state because a loss of resilience can go unnoticed for many years and then become disproportionately more difficult to restore.

Relative Importance of Coral Cover, Habitat Complexity and Diversity in Determining the Structure of Reef Fish Communities

PubMed Central

Komyakova, Valeriya; Munday, Philip L.; Jones, Geoffrey P.

2013-01-01

The structure of coral reef habitat has a pronounced influence on the diversity, composition and abundance of reef-associated fishes. However, the particular features of the habitat that are most critical are not always known. Coral habitats can vary in many characteristics, notably live coral cover, topographic complexity and coral diversity, but the relative effects of these habitat characteristics are often not distinguished. Here, we investigate the strength of the relationships between these habitat features and local fish diversity, abundance and community structure in the lagoon of Lizard Island, Great Barrier Reef. In a spatial comparison using sixty-six 2m2 quadrats, fish species richness, total abundance and community structure were examined in relation to a wide range of habitat variables, including topographic complexity, habitat diversity, coral diversity, coral species richness, hard coral cover, branching coral cover and the cover of corymbose corals. Fish species richness and total abundance were strongly associated with coral species richness and cover, but only weakly associated with topographic complexity. Regression tree analysis showed that coral species richness accounted for most of the variation in fish species richness (63.6%), while hard coral cover explained more variation in total fish abundance (17.4%), than any other variable. In contrast, topographic complexity accounted for little spatial variation in reef fish assemblages. In degrading coral reef environments, the potential effects of loss of coral cover and topographic complexity are often emphasized, but these findings suggest that reduced coral biodiversity may ultimately have an equal, or greater, impact on reef-associated fish communities. PMID:24349455

Relative importance of coral cover, habitat complexity and diversity in determining the structure of reef fish communities.

PubMed

Komyakova, Valeriya; Munday, Philip L; Jones, Geoffrey P

2013-01-01

The structure of coral reef habitat has a pronounced influence on the diversity, composition and abundance of reef-associated fishes. However, the particular features of the habitat that are most critical are not always known. Coral habitats can vary in many characteristics, notably live coral cover, topographic complexity and coral diversity, but the relative effects of these habitat characteristics are often not distinguished. Here, we investigate the strength of the relationships between these habitat features and local fish diversity, abundance and community structure in the lagoon of Lizard Island, Great Barrier Reef. In a spatial comparison using sixty-six 2m(2) quadrats, fish species richness, total abundance and community structure were examined in relation to a wide range of habitat variables, including topographic complexity, habitat diversity, coral diversity, coral species richness, hard coral cover, branching coral cover and the cover of corymbose corals. Fish species richness and total abundance were strongly associated with coral species richness and cover, but only weakly associated with topographic complexity. Regression tree analysis showed that coral species richness accounted for most of the variation in fish species richness (63.6%), while hard coral cover explained more variation in total fish abundance (17.4%), than any other variable. In contrast, topographic complexity accounted for little spatial variation in reef fish assemblages. In degrading coral reef environments, the potential effects of loss of coral cover and topographic complexity are often emphasized, but these findings suggest that reduced coral biodiversity may ultimately have an equal, or greater, impact on reef-associated fish communities.

Exploring the nature of ecological specialization in a coral reef fish community: morphology, diet and foraging microhabitat use

PubMed Central

Brandl, Simon J.; Robbins, William D.; Bellwood, David R.

2015-01-01

Patterns of ecological specialization offer invaluable information about ecosystems. Yet, specialization is rarely quantified across several ecological niche axes and variables beyond the link between morphological and dietary specialization have received little attention. Here, we provide a quantitative evaluation of ecological specialization in a coral reef fish assemblage (f. Acanthuridae) along one fundamental and two realized niche axes. Specifically, we examined ecological specialization in 10 surgeonfish species with regards to morphology and two realized niche axes associated with diet and foraging microhabitat utilization using a recently developed multidimensional framework. We then investigated the potential relationships between morphological and behavioural specialization. These relationships differed markedly from the traditional ecomorphological paradigm. While morphological specialization showed no relationship with dietary specialization, it exhibited a strong relationship with foraging microhabitat specialization. However, this relationship was inverted: species with specialized morphologies were microhabitat generalists, whereas generalized morphotypes were microhabitat specialists. Interestingly, this mirrors relationships found in plant–pollinator communities and may also be applicable to other ecosystems, highlighting the potential importance of including niche axes beyond dietary specialization into ecomorphological frameworks. On coral reefs, it appears that morphotypes commonly perceived as most generalized may, in fact, be specialized in exploiting flat and easily accessible microhabitats. PMID:26354935

Exploring the nature of ecological specialization in a coral reef fish community: morphology, diet and foraging microhabitat use.

PubMed

Brandl, Simon J; Robbins, William D; Bellwood, David R

2015-09-22

Patterns of ecological specialization offer invaluable information about ecosystems. Yet, specialization is rarely quantified across several ecological niche axes and variables beyond the link between morphological and dietary specialization have received little attention. Here, we provide a quantitative evaluation of ecological specialization in a coral reef fish assemblage (f. Acanthuridae) along one fundamental and two realized niche axes. Specifically, we examined ecological specialization in 10 surgeonfish species with regards to morphology and two realized niche axes associated with diet and foraging microhabitat utilization using a recently developed multidimensional framework. We then investigated the potential relationships between morphological and behavioural specialization. These relationships differed markedly from the traditional ecomorphological paradigm. While morphological specialization showed no relationship with dietary specialization, it exhibited a strong relationship with foraging microhabitat specialization. However, this relationship was inverted: species with specialized morphologies were microhabitat generalists, whereas generalized morphotypes were microhabitat specialists. Interestingly, this mirrors relationships found in plant-pollinator communities and may also be applicable to other ecosystems, highlighting the potential importance of including niche axes beyond dietary specialization into ecomorphological frameworks. On coral reefs, it appears that morphotypes commonly perceived as most generalized may, in fact, be specialized in exploiting flat and easily accessible microhabitats. © 2015 The Author(s).

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

USGS Publications Warehouse

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

2016-05-18

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

Vulnerability of Coral Reefs to Bioerosion From Land-Based Sources of Pollution

NASA Astrophysics Data System (ADS)

Prouty, Nancy G.; Cohen, Anne; Yates, Kimberly K.; Storlazzi, Curt D.; Swarzenski, Peter W.; White, Darla

2017-12-01

Ocean acidification (OA), the gradual decline in ocean pH and [CO32-] caused by rising levels of atmospheric CO2, poses a significant threat to coral reef ecosystems, depressing rates of calcium carbonate (CaCO3) production, and enhancing rates of bioerosion and dissolution. As ocean pH and [CO32-] decline globally, there is increasing emphasis on managing local stressors that can exacerbate the vulnerability of coral reefs to the effects of OA. We show that sustained, nutrient rich, lower pH submarine groundwater discharging onto nearshore coral reefs off west Maui lowers the pH of seawater and exposes corals to nitrate concentrations 50 times higher than ambient. Rates of coral calcification are substantially decreased, and rates of bioerosion are orders of magnitude higher than those observed in coral cores collected in the Pacific under equivalent low pH conditions but living in oligotrophic waters. Heavier coral nitrogen isotope (δ15N) values pinpoint not only site-specific eutrophication, but also a sewage nitrogen source enriched in 15N. Our results show that eutrophication of reef seawater by land-based sources of pollution can magnify the effects of OA through nutrient driven-bioerosion. These conditions could contribute to the collapse of coastal coral reef ecosystems sooner than current projections predict based only on ocean acidification.