Coral Bleaching

Background: The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. Conclusions/Significance: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.

Coral reefs support the livelihood of millions of people especially those engaged in marine fisheries activities. Coral reefs are highly vulnerable to climate change induced stresses that have led to substantial coral mortality over large spatial scales. Such climate change impacts have the potential to lead to declines in marine fish production and compromise the livelihoods of fisheries dependent communities. Yet few studies have examined social vulnerability in the context of changes specific to coral reef ecosystems. In this paper, we examine three dimensions of vulnerability (exposure, sensitivity, and adaptive capacity) of 29 coastal communities across five western Indian Ocean countries to the impacts of coral bleaching on fishery returns. A key contribution is the development of a novel, network-based approach to examining sensitivity to changes in the fishery that incorporates linkages between fishery and non-fishery occupations. We find that key sources of vulnerability differ considerably within and between the five countries. Our approach allows the visualization of how these dimensions of vulnerability differ from site to site, providing important insights into the types of nuanced policy interventions that may help to reduce vulnerability at a specific location. To complement this, we develop framework of policy actions thought to reduce different aspects of vulnerability at varying spatial and temporal scales. Although our results are specific to reef fisheries impacts from coral bleaching, this approach provides a framework for other types of threats and different social-ecological systems more broadly.

Degradation and mortality of corals is increasing worldwide and is expected to have significant effects on coral reef fish; hence studies on these effects are essential. In the present study, a field experiment was set up within Mafia Island Marine Park in Tanzania (East Africa) to examine the effects of bleaching and habitat structure on colonisation of coral reef fish assemblages. Live and bleached staghorn coral Acropora formosa was transplanted onto plots in a site dominated by sand and rubble, and the experimental design comprised of three treatments: live coral, bleached coral and eroded coral rubble. There was an immediate increase (within 24 h) in fish abundance and diversity in the two treatments with standing corals. Overall, live and bleached coral plots showed similar effects, but differed from the eroded coral plots which had a much lower abundance and diversity of fish. In general, fish species diversity changed with time over the study period while fish abundance did not. Multivariate analyses showed that while there were differences in fish assemblage structure between standing corals and the eroded coral treatment, there was neither a difference between live and bleached coral treatments nor any temporal effects on fish assemblage structure. Our findings suggest that physical structure and complexity of habitat have stronger effects on colonisation of reef fish assemblages than changes in coral health (such as bleaching) which do not affect coral structure. This may have important implications for appropriate coral reef management.

Vibrio shiloi , the causative agent of bleaching of the coral Oculina patagonica in the Mediterranean Sea, is present in all bleached O. patagonica corals in the summer (25-30 ∞ ∞ ∞ ∞ C), but can be not detected in the coral during the winter (16-20 ∞ ∞ ∞ ∞ C). Furthermore, the pathogen can not survive in O. patagonica at temperatures below 20 ∞ ∞ ∞ ∞ C. Using fluorescence in situ hybridization (FISH) with a V. shiloi -specific oligonucleotide probe, we found that the marine fireworm Hermodice caranculata is a winter reservoir for V. shiloi . Worms taken directly from the sea during the winter contained ~ 10 8 V. shiloi per worm by FISH analysis. However, colony-forming units (cfu) revealed only 4.1-18.3 ¥ ¥ ¥ ¥ 10 4 V. shiloi per worm, indicating that ~ 99.9% of them were in the viable-but-not-culturable (VBNC) state. When worms were infected with V. shiloi , most of the bacteria adhered to the worm within 24 h and then penetrated into epidermal cells. By 48 h, less than 10 ----4 of the intact V. shiloi in the worm gave rise to colonies, suggesting that they differentiated inside the worm into the VBNC state. When worms infected with V. shiloi were placed in aquaria containing O. patagonica , all of the corals showed small patches of bleached tissue in 7-10 days and total bleaching in 17 days. This is the first report of a reservoir and vector for a coral disease.

Large-scale coral bleaching was recorded as early as 1931, but severe bleaching on a regional or global scale was not documented until 1983. We use records from a global database of bleaching records to show that severe bleaching events occurred at a global level on four recent occasions and demonstrate that these events occurred in close temporal proximity to a strong negative deviation in the Southern Oscillation Index. While there was no clear increase in the frequency or intensity of major global bleaching events, the number of bleaching records clearly increased during the past three decades. However, increased vigilance and reporting of mild bleaching by an ever-increasing number of researchers and conservation-minded divers has confounded efforts to definitively separate changes in bleaching frequency from changes in reporting.

This report summarises the status of coral reefs in the ROPME Sea Area which includes Bahrain, Iran, Kuwait, Oman, Qatar, Saudi Arabia and United Arab Emirates (UAE); there are no coral reefs in Iraq. The region can be split into three parts according to the local marine climate, which strongly influences the nature of the coral communities: the Persian/Arabian Gulf

Background: The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. Conclusions/Significance: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.

This report summarises the status of coral reefs in the ROPME Sea Area which includes Bahrain, Iran, Kuwait, Oman, Qatar, Saudi Arabia and United Arab Emirates (UAE); there are no coral reefs in Iraq. The region can be split into three parts according to the local marine climate, which strongly influences the nature of the coral communities: the Persian/Arabian Gulf

As in the tropical Atlantic, Acropora populations in the southern Persian/Arabian Gulf plummeted within two decades after having been ecosystem engineers on most wave-exposed reefs since the Pleistocene. Since 1996/1998 live coral cover in the Gulf declined by over 90% in many areas, primarily due to bleaching and diseases
caused by rising temperatures. In the formerly dominant table-coral species A. downingi, population dynamics corresponding to disturbance regimes was quantified in three transition matrices (lower disturbance pre-1996; moderate disturbance from 1998 to 2010 and 2013 to 2017, disturbed in 1996/1998, 2010/11/12, 2017). Increased disturbance frequency and severity caused progressive reduction in coral size, cover, and population fecundity. Small size-classes were bolstered more
by partial colony mortality than sexual recruitment. Some large corals had a size refuge and resisted die-back but were also lost with  increasing disturbance. Matrix
and biophysical larval flow models suggested one metapopulation. Southern, Arabian, populations could be connected to northern, Iranian, populations but this connectivity was lost under assumptions of pelagic larval duration at rising temperatures shortened to a third. Then, the metapopulation disintegrated into isolated populations. Connectivity required to avoid extinctions increased exponentially with disturbance frequency and correlation of disturbances across the metapopulation.
Populations became unsustainable at eight disturbances in 15 years, when even highest theoretical recruitment no longer compensated mortality. This lethal disturbance frequency was 3-fold that of the moderately disturbed monitoring period and 4-fold of the preceding low-disturbance period—suggesting ongoing shortening of the disturbance-free period. Observed population collapse and environmental changes in the Gulf suggest that A. downingi is heading toward at least functional extinction mainly due to increasingly frequent temperature-induced mortality events, clearly linked to climate change

SUMMARY Nitric oxide (NO) is a free radical implicated in numerous cell signaling,physiological and pathophysiological processes of eukaryotic cells. Here, we describe the production of NO as part of the cellular stress response of the symbiotic sea anemone Aiptasia pallida, which hosts dinoflagellates from the genus Symbiodinium. We show that exposure to elevated temperatures induces symbiotic anemones to produce high levels of NO, leading to the collapse of the symbiosis. These results shed light on the poorly understood cellular mechanism through which elevated seawater temperature causes the release of symbiotic algae from symbiotic cnidarians, a detrimental process known as coral (cnidarian) bleaching. The results presented here show that the host cell is a major source of NO during exposure to elevated temperatures and that this constitutes a cytotoxic response leading to bleaching. These results have important evolutionary implications as the observed NO production in these b...

Coral reef banks may form an important component of mesophotic coral ecosystems (MCEs) in the Caribbean, but remain poorly explored relative to shallower reefs and mesophotic habitats on slopes and walls. Consequently, the processes structuring mesophotic coral reef communities are not well understood, particularly the role of disturbance. A large and regionally important mesophotic system, the Hind Bank Marine Conservation District (MCD), St. Thomas, USVI, was systematically surveyed. Data were used to construct a comprehensive benthic habitat map for the MCD, describe the abiotic and biotic components of the benthos among habitats, and investigate patterns of coral health among habitats. Two thirds of the MCD (23.6 km2) was found to be dense coral reef (Coral Cover = 24.1%) dominated by the Montastraea annularis species complex. Coral reef ecosystems were topographically complex, but could be classified into distinct habitat types, including high coral banks (35.8% of the MCD) and two large novel coral reef habitat types corresponding to an extremely flat basin (18%) and a highly rugose hillock basin (6.5%), containing thousands of coral knolls (2–10 m high). An extreme disease event with undescribed signs of mortality occurred on 47% of coral reefs and reached a high prevalence in affected areas (42.4% ± 6.3 SE, N = 26). The disease was significantly clustered in the basin habitats of the western MCD (global Moran’s I = 0.32, P\0.01). Observations of the spatial pattern suggested that the driver was specific to the basin habitats and may have been caused by a coherent abiotic event.

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

During the past two decades, coral reefs have experienced extensive degradation worldwide. One etiology for this global degradation is a syndrome known as coral bleaching. Mass coral bleaching events are correlated with increased sea-surface temperatures, however, the cellular mechanism underlying this phenomenon is uncertain. To determine if oxidative stress plays a mechanistic role in the process of sea-surface temperature-related coral bleaching, we examined corals along a depth transect in the Florida Keys over a single season that was characterized by unusually high sea-surface temperatures. We observed strong positive correlations between accumulation of oxidative damage products and bleaching in corals over a year of sampling. High levels of antioxidant enzymes and small heat-shock proteins were negatively correlated with levels of oxidative damage products. Corals that experienced oxidative stress had higher chaperonin levels and protein turnover activity. Our results indicate that coral bleaching is tightly coupled to the antioxidant and cellular stress capacity of the symbiotic coral, supporting the mechanistic model that coral bleaching (zooxanthellae loss) may be a final strategy to defend corals from oxidative stress.

The early effects of heat stress on the photosynthesis of symbiotic dinoflagellates (zooxanthellae) within the tissues of a reef-building coral were examined using pulseamplitude-modulated (PAM) chlorophyll fluorescence and photorespirometry. Exposure of Stylophora pistillata to 33 and 34°C for 4 h resulted in (1) the development of strong non-photochemical quenching (qN) of the chlorophyll fluorescence signal, (2) marked decreases in photosynthetic oxygen evolution, and (3) decreases in optimal quantum yield (F v /F m ) of photosystem II (PSII). Quantum yield decreased to a greater extent on the illuminated surfaces of coral branches than on lower (shaded) surfaces, and also when high irradiance intensities were combined with elevated temperature (33°C as opposed to 28°C). qN collapsed in heat-stressed samples when quenching analysis was conducted in the absence of oxygen. Collectively, these observations are interpreted as the initiation of photoprotective dissipation of excess absorbed energy as heat (qN) and O 2 -dependent electron flow through the Mehler-Ascorbate-Peroxidase cycle (MAP-cycle) following the point at which the rate of light-driven electron transport exceeds the capacity of the Calvin cycle. A model for coral bleaching is proposed whereby the primary site of heat damage in S. pistillata is carboxylation within the Calvin cycle, as has been observed during heat damage in higher plants. Damage to PSII and a reduction in F v /F m (i.e. photoinhibition) are secondary effects following the overwhelming of photoprotective mechanisms by light. This secondary factor increases the effect of the primary variable, temperature. Potential restrictions of electron flow in heat-stressed zooxanthellae are discussed with respect to Calvin cycle enzymes and the unusual status of the dinoflagellate Rubisco. Significant features of our model are that (1) damage to PSII is not the initial step in the sequence of heat stress in zooxanthellae, and (2) light plays a key secondary role in the initiation of the bleaching phenomena.

The first major ethnography of reef scientists, Coral Whisperers, begins with a clear distinction between hope and despair, but Irus Braverman’s ultimate goal is to reveal the ways these positions are “interconnected and even co-dependant” among those working on reef futures in laboratories and lagoons. Moving beyond extremes, she claims, might “show us the way out” of our apocalyptic trajectory. Her ethnography uses a fast-moving set of narratives based on interviews with 100 coral scientists and reef managers to show that these researchers are more than just experts on reefs: they are “spokespeople” and “guides” that might lead other conservationists—and all of us—“through the perils of the Anthropocene.” Part of the reason why that these Charon-like scientists can take leading roles, she claims, is because corals are “good to think with"—a phrase that appears in many multispecies studies, borrowed from the English translation of Levi-Strauss’ Totemism (1962). Braverman uses “good to think with” in a familiar multispecies register, but the coral thinking that she reveals—through a detailed retelling of competing scientific narratives—is neither easy nor good. Corals, it seems, are incredibly difficult to think with. They make trouble for seemingly stable categories of nature, life, death, and law as scientists attempt to speak for and with them.

One of the main obstacles for biological assessments of coral reefs over large spatial scales is the ability to link data obtained at the laboratory scale to spatially large data sets. This is particularly the case when trying to assess the ecological function of microbial processes following dramatic large-scale events such as mass coral bleaching. To be able to infer ecological function of field corals from laboratory measurement standardised to surface area it is imperative to be able to measure the actual surface area of corals in-situ. There have been several approaches proposed to estimate the three-dimensional surface area of field corals. While these have been shown to be reliable for simple coral growth forms, large degrees of error are introduced when applying them to complex growth forms. This paper refines a technique for calculating the three-dimensional surface area based on the projected surface area, with errors associated with complex growth forms reduced to b 5%. Once developed, the simple mathematical relationship (called the surface index) can be used to estimate the three-dimensional surface area of field corals from photograph or video imagery, allowing physiological parameters of corals determined at the sub-colony scale to whole colony and spatially large data sets of coral reefs. The effectiveness of using laser scanning techniques to derive threedimensional images of corals is also discussed.

Sea surface temperatures were warmer throughout 1998 at Sesoko Island, Japan, than in the 10 preceding years. Temperatures peaked at 2.8 8C above average, resulting in extensive coral bleaching and subsequent coral mortality. Using random quadrat surveys, we quantitatively documented the coral community structure one year before and one year after the bleaching event. The 1998 bleaching event reduced coral species richness by 61% and reduced coral cover by 85%. Colony morphology affected bleaching vulnerability and subsequent coral mortality. Finely branched corals were most susceptible, while massive and encrusting colonies survived. Most heavily impacted were the branched Acropora and pocilloporid corals, some of which showed local extinction. We suggest two hypotheses whose synergistic effect may partially explain observed mortality patterns (i.e. preferential survival of thick-tissued species, and shape-dependent differences in colony mass-transfer efficiency). A community-structural shift occurred on Okinawan reefs, resulting in an increase in the relative abundance of massive and encrusting coral species.

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

Coral reefs support the livelihood of millions of people especially those engaged in marine fisheries activities. Coral reefs are highly vulnerable to climate change induced stresses that have led to substantial coral mortality over large spatial scales. Such climate change impacts have the potential to lead to declines in marine fish production and compromise the livelihoods of fisheries dependent communities. Yet few studies have examined social vulnerability in the context of changes specific to coral reef ecosystems. In this paper, we examine three dimensions of vulnerability (exposure, sensitivity, and adaptive capacity) of 29 coastal communities across five western Indian Ocean countries to the impacts of coral bleaching on fishery returns. A key contribution is the development of a novel, network-based approach to examining sensitivity to changes in the fishery that incorporates linkages between fishery and non-fishery occupations. We find that key sources of vulnerability differ considerably within and between the five countries. Our approach allows the visualization of how these dimensions of vulnerability differ from site to site, providing important insights into the types of nuanced policy interventions that may help to reduce vulnerability at a specific location. To complement this, we develop framework of policy actions thought to reduce different aspects of vulnerability at varying spatial and temporal scales. Although our results are specific to reef fisheries impacts from coral bleaching, this approach provides a framework for other types of threats and different social-ecological systems more broadly.

Coral reefs are formed as a result of symbioses between anthozoan cnidarians and dinoflagellate symbionts of the genus Symbiodinium. In recent years there has been an increase in mass bleaching events. These events are not well understood and more insight is necessary into the physiological and molecular interactions involved in the breakdown and potential recovery of the symbiotic association. This study aims to measure the influence of Symbiodinium type on the autotrophic potential of the symbiosis, as a means of assessing the physiological implications of establishing novel host-symbiont combinations after a bleaching event. Symbiont-free anemones of the genus Aiptasia were used as model organisms for corals and reinfected with different Symbiodinium strains. Over the course of twelve weeks, maximum photosynthetic and dark respiratory oxygen fluxes were measured using a micro-respirometer. The translocation rate of photosynthetically-fixed carbon from the symbionts to the host was estimated. These various fluxes were then used to infer the potential contribution of different strains of zooxanthellae to the host's daily respiratory carbon requirements (CZAR) during symbiosis re-establishment. The photo-physiological patterns observed will be described and compared amongst the various host-symbiont associations. The resultant implications for the recovery of corals from bleaching events will also be discussed.

Since the IPCC Third Assessment Report (TAR), our understanding of the implications of climate change for coastal systems and low-lying areas (henceforth referred to as 'coasts') has increased substantially and six important policy-relevant messages have emerged. Coasts are experiencing the adverse consequences of hazards related to climate and sea level (very high confidence). Coasts are highly vulnerable to extreme events, such as storms, which impose substantial costs on coastal societies [6.2.1, 6.2.2, 6.5.2]. Annually, about 120 million people are exposed to tropical cyclone hazards, which killed 250,000 people from 1980 to 2000 [6.5.2]. Through the 20th century, global rise of sea level contributed to increased coastal inundation, erosion and ecosystem losses, but with considerable local and regional variation due to other factors [6.2.5, 6.4.1]. Late 20th century effects of rising temperature include loss of sea ice, thawing of permafrost and associated coastal retreat, and more frequent coral bleaching and mortality [6.2.5]. Coasts will be exposed to increasing risks, including coastal erosion, over coming decades due to climate change and sea-level rise (very high confidence). Anticipated climate-related changes include: an accelerated rise in sea level of up to 0.6 m or more by 2100; a further rise in sea surface temperatures by up to 3°C; an intensification of tropical and extratropical cyclones; larger extreme waves and storm surges; altered precipitation/run-off; and ocean acidification [6.3.2]. These phenomena will vary considerably at regional and local scales, but the impacts are virtually certain to be overwhelmingly negative [6.4, 6.5.3].

TABLE OF CONTENTS


Chapter 1: Fishing, turbid runoff, and climate change threaten coral reef fish communities in Puerto Rico (I-1 – I-48)

Edwin A. Hernández-Delgado, Bernard J. Rosado-Matías, &  Alberto M. Sabat


Chapter 2: Post-bleaching characterization of coral reef fish communities in Arrecifes La Cordillera Natural Reserve (II-1 – II-100)

Edwin A. Hernández-Delgado & Alberto M. Sabat


Chapter 3: Impacts of low water transparency and bombing activities on selected coral reef sites in Puerto Rico (III-1 – III-45)

Edwin A. Hernández-Delgado


Chapter 4: Impacts of the 2005 massive coral bleaching event on selected coral reef sites in Puerto Rico (IV-1 – IV-95)

Edwin A. Hernández-Delgado, Héctor J. Claudio, Jean Lassus, Mary Ann Lucking, Jaime Fonseca, Kathy Hall, & José Rafols,


Chapter 5: Increased vulnerability to climate change impacts on remote Mona Island’s coral reefs following the 2005-2006 post-
bleaching mass coral mortality event (V-1 – V-42)

Edwin A. Hernández-Delgado, Héctor Claudio, Jaime Fonseca, & Samuel Suleimán


Chapter 6: Impacts of non-point source sewage pollution on selected coral reef sites in Puerto Rico (VI-1 – VI-54)

Edwin A. Hernández-Delgado, Betzaida Sandoz, Michelle Bonkosky, José Norat-Ramírez, & Hernando Mattei

Vibrio shiloi , the causative agent of bleaching of the coral Oculina patagonica in the Mediterranean Sea, is present in all bleached O. patagonica corals in the summer (25-30 ∞ ∞ ∞ ∞ C), but can be not detected in the coral during the winter (16-20 ∞ ∞ ∞ ∞ C). Furthermore, the pathogen can not survive in O. patagonica at temperatures below 20 ∞ ∞ ∞ ∞ C. Using fluorescence in situ hybridization (FISH) with a V. shiloi -specific oligonucleotide probe, we found that the marine fireworm Hermodice caranculata is a winter reservoir for V. shiloi . Worms taken directly from the sea during the winter contained ~ 10 8 V. shiloi per worm by FISH analysis. However, colony-forming units (cfu) revealed only 4.1-18.3 ¥ ¥ ¥ ¥ 10 4 V. shiloi per worm, indicating that ~ 99.9% of them were in the viable-but-not-culturable (VBNC) state. When worms were infected with V. shiloi , most of the bacteria adhered to the worm within 24 h and then penetrated into epidermal cells. By 48 h, less than 10 ----4 of the intact V. shiloi in the worm gave rise to colonies, suggesting that they differentiated inside the worm into the VBNC state. When worms infected with V. shiloi were placed in aquaria containing O. patagonica , all of the corals showed small patches of bleached tissue in 7-10 days and total bleaching in 17 days. This is the first report of a reservoir and vector for a coral disease.

Recent large scale climatic events have had a tremendous impact on coral reefs of this region. The isolated, less-developed reefs of the Mexican Pacific suffered 40-50% coral mortality during the La Niña related cold-water events, following the 1998 El Niño bleaching event. The extensive, well-developed reefs on the Atlantic coast experienced unprecedented mass coral bleaching and mortality in 1995 and again in 1998, followed by

The Chagos Archipelago designated as a no-take marine protected area in 2010, lying about 500 km south of the Maldives in the Indian Ocean, has a high conservation priority, particularly because of its fast recovery from the ocean-wide massive coral mortality following the 1998 coral bleaching event. The aims of this study were to examine Symbiodinium diversity and distribution associated with scleractinian corals in five atolls of the Chagos Archipelago, spread over 10,000 km 2. Symbiodinium clade diversity in 262 samples of seven common coral species, Acropora muricata, Isopora palifera, Pocillopora damicornis, P. verrucosa, P. eydouxi, Seriatopora hystrix, and Stylophora pistillata were determined using PCR-SSCP of the ribosomal internal transcribed spacer 1 (ITS1), PCR-DDGE of ITS2, and phylogenetic analyses. The results indicated that Symbiodinium in clade C were the dominant symbiont group in the seven coral species. Our analysis revealed types of Symbiodinium clade C specific...

The deleterious effects of temperature-induced coral bleaching, a process by which corals lose their endosymbiotic algae (zooxanthellae; genus Symbiodinium) primarily at temperatures above mean yearly maximums, has not been well described for alcyonacean soft corals (Coelenterata, Octocorallia). The study of Symbiodinium cells lost from Sarcophyton ehrenbergi, Sinularia sp., and Xenia sp., which have not been compared in bleaching studies, indicate that the soft coral S. ehrenbergi released the greatest number of symbiont cells, however, it was less susceptible to heat stress surviving temperatures of 34 8C for N39 h. Sinularia sp. showed intermediate levels of bleaching tolerance to elevated temperatures, surviving prolonged exposures at 32 8C, but dying within 24 h at 34 8C. Xenia sp., however, was the most vulnerable to high heat stress maximally releasing Symbiodinium at temperatures V30 8C. This evidence indicates that Xenia sp. is even more susceptible to elevated temperatures than Acropora spp., previously reported to be the most vulnerable coral species to elevated temperature-induced bleaching.

TABLE OF CONTENTS


Chapter 1: Thirteen years of climate-related non-linear disturbance and coral reef ecological collapse: Culebra Island, Puerto Rico (4 – 81)

Edwin A. Hernández-Delgado


Chapter 2: Decadal-scale demographics of massive bleaching and mortality in the major Caribbean reef-building star coral,  Montastraea annularis (Ellis & Solander): A modeling approach (82 – 109)

Raisa Hernández-Pacheco, Edwin A. Hernández-Delgado, &
Alberto M. Sabat


Chapter 3: Sediment stress, water turbidity, and sewage pollution associated to rapid degradation of Federal Designated Critical Habitats of the threatened Elkhorn Coral (Acropora palmata) in Vega Baja, P.R. (110 – 247)

Edwin A. Hernández-Delgado, Yahaira Hutchinson-Delgado,
Ricardo Laureano, Raisa Hernández-Pacheco, Tagrid M. Ruiz-
Maldonado, Julio Oms, and Pedro L. Díaz


Chapter 4: Biological characterization of shallow-water coral reef communities across a water quality stress gradient within the
Canal Luis Peña Natural Reserve, Culebra Island, Puerto Rico (248 – 326)

Edwin A. Hernández-Delgado, Jeiger Medina, Vanessa Ortiz, Marilisa Mas, Pablo A. Marrero, H. Mattei, & José Norat-Ramírez


Chapter 5: Baseline biological characterization of coral reefs at Punta Cucharas Natural Reserve, Ponce, PR (327 – 379)

Edwin A. Hernández-Delgado

Bleaching of corals by loss of symbiotic dinoflagellate algae and/or photosynthetic pigments is commonly triggered by elevated temperatures coupled with high irradiance, and is a first-order threat to coral reef communities. In this study, a high-resolution high-performance liquid chromatography method integrated with mass spectrometry was applied to obtain the first definitive identification of chlorophyll and carotenoid pigments of three clades of symbiotic dinoflagellate algae ( Symbiodinium ) in corals, and their response to experimentally elevated temperature and irradiance. The carotenoids peridinin, dinoxanthin, diadinoxanthin (Dn), diatoxanthin (Dt) and b -carotene were detected, together with chlorophylls a and c 2 , and phaeophytin a , in all three algal clades in unstressed corals. On exposure to elevated temperature and irradiance, three coral species ( Montastrea franksi and Favia fragum with clade B algae, and Montastrea cavernosa with clade C) bleached by loss of 50-80% of their algal cells, with no significant impact to chlorophyll a or c 2 , or peridinin in retained algal cells. One species ( Agaricia sp. with clade C) showed no significant reduction in algal cells at elevated temperature and irradiance, but lost substantial amounts of chlorophyll a and carotenoid pigments, presumably through photo-oxidative processes. Two coral species ( Porites astreoides and Porites porites both bearing clade A algae) did not bleach. The impact of elevated temperature and irradiance on the levels of the photoprotective xanthophylls (Dn + Dt) and b -carotene varied among the corals, both in pool size and xanthophyll cycling, and was not correlated to coral bleaching resistance.

Ascidians can settle and grow on corals and have become one of the main threats to hard corals in some areas of world, covering and smothering live coral tissues. We studied the biology of infestation of a solitary tunicate, Phallusia nigra Savigny, 1816, on hard corals in Chabahar Bay, a subtropical bay in the northern Gulf of Oman. Infested corals were bleached and eroded at epibiont attachment surfaces. The magnitude of infestation by the tunicate differed between Pocillopora and Acropora coral colonies, with more tunicates inhabiting Pocillopora colonies. This preference of P. nigra for Pocillopora may be attributed to differences in morphology (e.g. narrower branch spaces in Pocillopora) of the coral genera. Outbreaks of ascidians on coral reefs are usually associated with anthropogenic activities. P. nigra may have more localized damaging effects on hosts, in contrast to colonial ascidians that can kill entire coral colonies. These effects may be exaggerated by non-contact effects (e.g. decreased pH).

Climate change and global warming have severe consequences for the survival of scleractinian (reefbuilding) corals and their associated ecosystems. This review summarizes recent literature on the influence of temperature on coral growth, coral bleaching, and modelling the effects of high temperature on corals. Satellite-based sea surface temperature (SST) and coral bleaching information available on the internet is an important tool in monitoring and modelling coral responses to temperature. Within the narrow temperature range for coral growth, corals can respond to rate of temperature change as well as to temperature per se. We need to continue to develop models of how non-steady-state processes such as global warming and climate change will affect coral reefs.

Degraded coral reef ecosystems yield limited goods and services, which is expected to have significant socio-economic impacts on isolated tropical island communities with strong reliance on coral reefs. This study investigates socio-economic changes, specifically in fresh fish consumption and fishing activities, associated with environmental degradation at five fishing grounds (qoliqoli) in the Lau Islands (Fiji). Semi-structured interviews with fishers and senior household members revealed that the importance of fishing was low relative to other occupations, and consumption of fresh fish has declined over the last decade. Reduced fishing and choice of fresh fish is largely attributable to an increased need to derive income as well as new income-generating opportunities. A possible consequence of reduced reliance on marine resources was limited awareness of recent environmental degradation caused by climate-induced coral bleaching and outbreaks of coral-feeding crown-of-thorns starfish. Limited use and reduced awareness of the local marine environment in the short term may erode social memory and local ecological knowledge, reducing opportunities to fall back on marine resources. This may also compromise long-term economic and social stability. Conversely, low reliance on marine resources may confer greater flexibility to adapt to future ecological change in the marine environment. Importantly, changes in fish consumption and exploitation of marine resources were linked to socio-economic factors rather than a consequence of recent degradation of marine environments. Greater knowledge of the dynamics driving change in marine resource use is necessary to understand how societies respond to ecological and socio-economic change, and to identify opportunities for adaptive sustainable ecosystem management.

A long-term study of coral reef ecology in the Gulf of Thailand provides a good opportunity to examine the temporal variation on the impact of mass coral bleaching at those reef sites. We compared the bleaching and mortality of corals between the mass bleaching events in 1998 and 2010 at a coral community in the Western Gulf of Thailand. The aim was to identify the coral species which were most likely to suffer from (and to be able to tolerate) changes in seawater temperature. Significant differences in the susceptibility of the coral taxa to bleaching events between the years 1998 and 2010 and among coral species were documented. Bleaching was significantly different between the most dominant corals. Diploastrea heliopora was the most resistant coral to bleaching in both years. Some coral species showed more resistance to bleaching in 2010. The coral mortality following the mass bleaching events in 1998 and 2010 varied significantly between the years and the coral taxa. Mortality of some dominant coral taxa was also lower in 2010. Seven coral species, i.e. Astreopora myriophthalma, Pachyseris rugosa, Turbinaria mesenterina, Goniastrea pectinata, Favia pallida, F. maritima, Favites halicora, Platygyra daedalea and Galaxea fascicularis, were tolerant to the coral bleaching events. An ecosystem-based approach to managing coral reefs in the Gulf of Thailand is needed to identify appropriate marine protected area networks and to strengthen marine and coastal resource policies in order to build coral reef resilience.

In its most basic definition, Skin Lightening products are the use of chemical substances to lighten one's skin tone. From laser treatments to bleaching creams, there are a number of different products and methods that can be used to lighten your skin color. Before you choose a particular product, it is recommended that you first consult your dermatologist to choose a product that will not inadvertently harm your skin. So why do people choose to lighten their skin? Here is a look at the top six reasons why: 1) To Lighten Dark Skin Patches On the Elbows and Underarms-These areas of the skin tend to be darker than the skin on the rest of the body, especially in individuals with light and fair complexions. A high quality skin cream can assist in lightening these patches of skin. 2) To Remove Acne Scars-Those who suffer from acne know that it can be a traumatizing experience. One of the side effects of suffering from acne is that it discolors the skin, and it can make a person feel self-conscious. The proper Skin Lightening cream can reduce the appearance of discoloration. 3) To Reduce the Appearance of Sun Spots-Many people, but especially women, suffer from sunspots or freckles from prior exposure to the sun. Your dermatologist can recommend a natural skin lightener that will assist in reducing their appearance. 4) Even out Your Skin Tone and Brighten Your Complexion-Everyone desires to have bright, healthy and glowing skin. The use of a safe Skin Lightening cream can reveal a brighter complexion and even one's skin tone. A better complexion will increase your self-confidence and give you a reason to smile more often. 5) Affordability-Skin Lightening products, such as creams, are more affordable than traditional laser treatments that are used to lighten skin. Because laser treatments must be performed in a doctor's office, they can be quite expensive, and in most instances, your insurance will not cover their cost. 6) Safety-In the past, women have used homemade products and dangerous skin bleaches to lighten their skin tones. Often times, these bleaching creams contain dangerous ingredients, such as mercury. Therefore, it is important for to choose products that are only recommended by your dermatologist. These are just some reasons a person may choose to use skin-lightening products whether it be a cream or an ointment. The choice is a personal one and any person choosing this route should be sure of their decision before starting the process. Are you looking for more information regarding skin lightening cream Click Here.

Coral bleaching involves the loss of symbiotic algae (zooxanthellae) from reef corals and other cnidarians during periods of environmental stress, particularly elevated temperature. In this study we compared the thermal bleaching responses of the zoanthid Palythoa caribaeorum from three populations along the southeast coast of Florida. Winter (2002–2003) and summer (2003) samples from three geographically separate sites were experimentally exposed to increased temperatures and the loss of zooxanthellae was measured. Population densities of zooxanthellae were analyzed and their genetic identity determined using PCR-DGGE analysis of the internal transcribed spacer region 2. The results showed that samples of P. caribaeorum from reefs that experienced the smallest range in annual seawater temperature released the most zooxanthellae. Seasonal comparisons revealed that winter samples lost more zooxanthellae than summer samples. P. caribaeorum harbored two genetic types of zooxanthellae, C1 and D1a. Individual colonies contained populations of only C1 or D1a, or combinations of C1 and D1a. However, these genotypic patterns did not relate latitudinal distribution nor to differences in experimental thermal tolerance.