scholarly journals A comparative baseline of coral disease in three regions along the Saudi Arabian coast of the central Red Sea

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0246854
Author(s):  
Greta Smith Aeby ◽  
Amanda Shore ◽  
Thor Jensen ◽  
Maren Ziegler ◽  
Thierry Work ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Red Sea ◽  
Human Impacts ◽  
Coral Cover ◽  
Coral Disease ◽  
Saudi Arabian ◽  
Disease Prevalence ◽  
Coral Diseases ◽  
White Syndrome ◽  
Growth Anomalies

Coral disease is a growing problem for coral reefs globally and diseases have been linked to thermal stress, excess nutrients, overfishing and other human impacts. The Red Sea is a unique environment for corals with a strong environmental gradient characterized by temperature extremes and high salinities, but minimal terrestrial runoff or riverine input and their associated pollution. Yet, relatively little is known about coral diseases in this region. Disease surveys were conducted at 22 reefs within three regions (Yanbu, Thuwal, Al Lith) in the central Red Sea along the Saudi Arabian coast. Surveys occurred in October 2015, which coincided with a hyperthermal-induced bleaching event. Our objectives were to 1) document types, prevalence, and distribution of coral diseases in a region with minimal terrestrial input, 2) compare regional differences in diseases and bleaching along a latitudinal gradient of environmental conditions, and 3) use histopathology to characterize disease lesions at the cellular level. Coral reefs of the central Red Sea had a widespread but a surprisingly low prevalence of disease (<0.5%), based on the examination of >75,750 colonies. Twenty diseases were recorded affecting 16 coral taxa and included black band disease, white syndromes, endolithic hypermycosis, skeletal eroding band, growth anomalies and focal bleached patches. The three most common diseases were Acropora white syndrome (59.1% of the survey sites), Porites growth anomalies (40.9%), and Porites white syndrome (31.8%). Sixteen out of 30 coral genera within transects had lesions and Acropora, Millepora and Lobophyllia were the most commonly affected. Cell-associated microbial aggregates were found in four coral genera including a first report in Stylophora. Differences in disease prevalence, coral cover, amount of heat stress as measured by degree heating weeks (DHW) and extent of bleaching was evident among sites. Disease prevalence was not explained by coral cover or DHW, and a negative relationship between coral bleaching and disease prevalence was found. The northern-most sites off the coast of Yanbu had the highest average disease prevalence and highest average DHW values but no bleaching. Our study provides a foundation and baseline data for coral disease prevalence in the central Red Sea, which is projected to increase as a consequence of increased frequency and severity of ocean warming.

scholarly journals A comparative baseline of coral disease across the central Red Sea

2021 ◽  
Author(s):  
Greta Smith Aeby ◽  
Amanda Shore ◽  
Thor Jensen ◽  
Maren Ziegler ◽  
Thierry Work ◽  
...  
Keyword(s):  
Red Sea ◽  
Coral Cover ◽  
Coral Disease ◽  
Negative Relationship ◽  
Cellular Level ◽  
Disease Prevalence ◽  
White Syndrome ◽  
Growth Anomalies ◽  
Disease Surveys ◽  
Black Band

AbstractThe Red Sea is a unique environment for corals with a strong environmental gradient characterized by temperature extremes and high salinities, but minimal terrestrial runoff or riverine input and their associated pollution. Disease surveys were conducted along 22 reefs in the central Red Sea along the Saudi Arabian coast in October 2015, which coincided with a bleaching event. Our objectives were to 1) document types, prevalence, and distribution of coral diseases in a region with minimal terrestrial input, 2) compare regional differences in diseases and bleaching along a latitudinal gradient of environmental conditions, and 3) use histopathology to characterize disease lesions at the cellular level. Coral reefs of the central Red Sea had a widespread but a surprisingly low prevalence of disease (<0.5%), based on the examination of >75,750 colonies. Twenty diseases were recorded affecting 16 coral taxa and included black band disease, white syndromes, endolithic hypermycosis, skeletal eroding band, growth anomalies and focal bleached patches. The three most common diseases were Acropora white syndrome (59.1% of the survey sites), Porites growth anomalies (40.9%), and Porites white syndrome (31.8%). Over half of the coral genera within transects had lesions and corals from the genera Acropora, Millepora and Lobophyllia were the most commonly affected. Cell-associated microbial aggregates were found in four coral genera resembling patterns found in the Indo-Pacific. Differences in disease prevalence, coral cover, amount of heat stress as measured by degree heating weeks (DHW) and extent of bleaching was evident among sites. Disease prevalence was not explained by coral cover or DHW, and a negative relationship between coral bleaching and disease prevalence was found. The northern-most sites off the coast of Yanbu had the highest average DHW values but absence of bleaching and the highest average disease prevalence was recorded. Our study provides a foundation and baseline data for coral disease prevalence in the Red Sea, which is projected to increase as a consequence of increased frequency and severity of ocean warming.

scholarly journals Status of Coral Health and Disease in Kessilampe Waters, Kendari, South East Sulawesi

2018 ◽  
Vol 23 (3) ◽  
pp. 137
Author(s):  
Ratna Diyah Palupi ◽  
Rahmadani Rahmadani ◽  
Ira Ira
Keyword(s):  
Water Quality ◽  
Coral Reefs ◽  
Coral Disease ◽  
White Spot ◽  
Aquatic Animal ◽  
Coral Diseases ◽  
White Syndrome ◽  
Health And Disease ◽  
Coral Health ◽  
Global Threat

Diseases of coral reef organisms have become a global threat to coral reefs and a major cause of reef deterioration. The presence of coral diseases influence marine resources productivity that interact with coral reefs. The purpose of this research is to identify coral disease types and prevalence which include coral health compromiser. Data collection was done by using 40 m2 belt transects at three observation stations. The result showed that the White Syndrome (WS), Bleaching, Ulcerative White Spot (UWS), Skeleton Eroding Band (SEB), White Patch (WP), and Non Focal Bleaching were found at research sites, while the coral health compromisers were Sediment damage, fish bite, invertebrate galls, flatworm infestation, and pigmentation response. In addition disease of White Syndrome (WS), Bleaching, and Ulcerative White Spot (UWS) were the main disease with prevalence of disease is approximately 4%, while the others were lower than 1%. Overall the prevalence of diseases (14,52%) is higher than compromise health (13,98%). A total of 186 coral colonies observed with 27 colonies were affected by diseases. Meanwhile, the waters quality (salinity, pH, and nitrate) were below the threshold quality standards for marine aquatic animal and not supported of coral organism was presume organisms against pathogens bacterial. Although the prevalence of coral disease is still in normal condition but the decrease of water quality can lead the risk. Good management is required from local government to improve the water quality especially from terrestrial impact.

scholarly journals Baseline coral disease surveys within three marine parks in Sabah, Borneo

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1391 ◽  
Author(s):  
Jennifer Miller ◽  
Michael J. Sweet ◽  
Elizabeth Wood ◽  
John Bythell
Keyword(s):  
National Parks ◽  
Human Impacts ◽  
Coral Cover ◽  
Coral Disease ◽  
Strong Dependence ◽  
The Other ◽  
Coral Diseases ◽  
Disease Surveys ◽  
Different Levels ◽  
Study Offer

Two of the most significant threats to coral reefs worldwide are bleaching and disease. However, there has been a scarcity of research on coral disease in South-East Asia, despite the high biodiversity and the strong dependence of local communities on the reefs in the region. This study provides baseline data on coral disease frequencies within three national parks in Sabah, Borneo, which exhibit different levels of human impacts and management histories. High mean coral cover (55%) and variable disease frequency (mean 0.25 diseased colonies m−2) were found across the three sites. Highest disease frequency (0.44 diseased colonies per m2) was seen at the site closest to coastal population centres. Bleaching and pigmentation responses were actually higher at Sipadan, the more remote, offshore site, whereas none of the other coral diseases detected in the other two parks were detected in Sipadan. Results of this study offer a baseline dataset of disease in these parks and indicate the need for continued monitoring, and suggest that coral colonies in parks under higher anthropogenic stressors and with lower coral cover may be more susceptible to contracting disease.

scholarly journals Coral Disease and the Environment in the  Pacific Ocean

2021 ◽  
Author(s):  
◽  
Gareth John Williams
Keyword(s):  
Environmental Conditions ◽  
Human Population ◽  
Coral Cover ◽  
Spatial Scales ◽  
Coral Disease ◽  
Host Density ◽  
Tissue Loss ◽  
Coral Diseases ◽  
Growth Anomalies ◽  
Growth Anomaly

<p>Coral diseases are a major threat to coral reef health and functioning worldwide. Little is known about how coral disease prevalence relates to multiple interacting changes in host densities, abiotic stressors, and levels of human impact. In particular, almost nothing is known about coral disease dynamics under changing abiotic conditions in the absence of direct anthropogenic stressors. Understanding how disease dynamics change relative to shifts in environmental conditions is crucial for the successful management and future survival of coral reefs. With the use of existing and novel field data and statistical modeling I examined the associations (abiotic and biotic) of multiple coral disease states across a variety of spatial scales encompassing a wide range of environmental conditions. Biomedical techniques were then used to relate these environmental associations to potential disease etiology. Study sites included areas with high levels of anthropogenic impact (e.g. Oahu, main Hawaiian Islands); to extremely remote quasi-pristine reefs removed from direct human influence (e.g. Palmyra Atoll National Wildlife Refuge). Over small spatial scales (100s m) at a marine reserve in the main Hawaiian Islands I modelled the spatial patterns of four coral diseases (Porites growth anomalies, Porites tissue loss, Porites trematodiasis and Montipora white syndrome). While Porites tissue loss and Montipora white syndrome were positively associated with poor environmental conditions (poor water quality, low coral cover), Porites growth anomalies and Porites trematodiasis were more prevalent in areas considered to be of superior quality (clearer water, increased host abundance, higher numbers of fish). At Palmyra Atoll, fatal tissue loss diseases were largely absent and although coral growth anomalies were present their prevalence was extremely low. Patterns of growth anomaly prevalence at Palmyra were positively associated with host abundance across four coral genera (Acropora, Astreopora, Montipora and Porites) and generally negatively associated with algal cover. Growth anomalies, although progressive and detrimental to the hosts, were most prevalent in the "healthiest" regions (the highest coral cover regions) of Palmyra. I hypothesised that differences seen in the types and prevalence of coral diseases between heavily populated parts of Hawaii and remote uninhabited locations such as Palmyra Atoll, could be a result of differing levels of either direct (e.g. pollution) or indirect (e.g. pollution leading to loss of key hosts) human stressors, in addition to natural changes in the environment. To begin disentangling the confounding effects of natural variability and human stressors on coral disease prevalence patterns I modelled two diseases (Acropora and Porites growth anomalies) across hundreds of sites throughout the Indo-Pacific Ocean (1000s km). Predictors included host densities, human population numbers, frequency of sea surface temperature anomalies, and input of ultra-violet radiation. Porites growth anomaly prevalence was positively associated with human population density (and to a lesser extent host density), while the prevalence of Acropora growth anomalies was strongly host density dependent. The positive association between the prevalence of Porites growth anomalies and human density suggests the presence and prevalence of the disease are related, directly or indirectly, to some environmental co-factor associated with increased human density at regional spatial scales. Although this association has been widely posited, this is one of the first wide scale studies unambiguously linking a coral disease with human population size. In summary, the types of coral diseases observed, their prevalence, and spatial patterns of distribution within reef systems are the result of multiple abiotic and biotic factors and stressors interacting, in some cases synergistically. Statistical modelling, in conjunction with biomedical techniques and field observations, proved essential to the understanding of coral disease ecology within single reefs and atolls to patterns across entire oceans.</p>

Coral cover and partial mortality on anthropogenically impacted coral reefs at Eilat, northern Red Sea

2004 ◽  
Vol 48 (3-4) ◽  
pp. 248-253 ◽  
Author(s):  
Jeffrey Wielgus ◽  
Nanette E. Chadwick-Furman ◽  
Zvy Dubinsky
Keyword(s):  
Coral Reefs ◽  
Red Sea ◽  
Coral Cover ◽  
Partial Mortality ◽  
Northern Red Sea

scholarly journals Coral Disease Time Series Highlight Size-Dependent Risk and Other Drivers of White Syndrome in a Multi-Species Model

2020 ◽  
Vol 7 ◽  
Author(s):  
Austin Greene ◽  
Megan J. Donahue ◽  
Jamie M. Caldwell ◽  
Scott F. Heron ◽  
Erick Geiger ◽  
...  
Keyword(s):  
Coral Disease ◽  
Negative Relationship ◽  
Coral Diseases ◽  
White Syndrome ◽  
Size Dependent ◽  
Multiple Species ◽  
Term Monitoring ◽  
Past Conditions

Coral diseases contribute to the decline of reef communities, but factors that lead to disease are difficult to detect. In the present study, we develop a multi-species model of colony-scale risk for the class of coral diseases referred to as White Syndromes, investigating the role of current or past conditions, including both environmental stressors and biological drivers at the colony and community scales. Investigating 7 years of coral survey data at five sites in Guam we identify multiple environmental and ecological associations with White Syndrome, including a negative relationship between short-term heat stress and White Syndrome occurrence, and strong evidence of increasing size-dependent White Syndrome risk across coral species. Our findings result in a generalized model used to predict colony-scale White Syndrome risk for multiple species, highlighting the value of long-term monitoring efforts to detect drivers of coral disease.

scholarly journals Characterization of the Coral Disease 'Porites Bleaching with Tissue Loss' (PBTL) From Hawaii

2021 ◽  
Author(s):  
◽  
Mareike Sudek
Keyword(s):  
Coral Reefs ◽  
Coral Disease ◽  
Seawater Temperature ◽  
Temporal Variations ◽  
Disease Prevalence ◽  
Tissue Loss ◽  
Disease Dynamics ◽  
Kaneohe Bay ◽  
Coral Colony ◽  
Bleaching Response

<p>Coral reefs around the world are facing many threats and have sustained severe losses in coral cover over the past few decades. Coral bleaching and disease outbreaks have contributed substantially to this reef decline, however our understanding of factors contributing to the increase in coral disease prevalence are poorly understood. Information on the disease dynamics of different diseases affecting a reef system is essential for the development of effective management strategies.  The aim of this research was to characterise and build a case study of a bleaching response affecting Porites compressa in Kaneohoe Bay, Oahu, Hawaii. It manifests as a localised, discrete area on the coral colony with a bleached coenenchyme and pigmented polyps, giving the affected area a “speckled” appearance. A disease by definition is any interruption, cessation or disorder of body functions, systems or organs. Results of this study showed that this localised bleaching causes tissue loss and a reduction in the number of gametes, and hence harm to the host. It was therefore classified as a disease and named Porites bleaching with tissue loss (PBTL). In addition, PBTL does not appear to represent a common thermal bleaching response as it was present throughout the year during times when seawater temperature was well within the coral’s thermal threshold.  Symbiodinium cell density in PBTL-affected areas of the coral colony was reduced by 65%, and examination of affected host tissue using light microscopy showed fragmentation and necrosis. However, no potential pathogen was observed. Transmission electron microscopy (TEM) revealed a high occurrence of potential apoptotic Symbiodinium cells and a potential increase in the abundance of virus-like particles (VLPs) in PBTL-affected tissue. However a causal relationship remains to be established. Long-term monitoring showed spatio-temporal variations in PBTL prevalence. Temporal variations in prevalence reflected a seasonal trend with a peak during the summer months, linked to increasing seawater temperature. Spatial variations in disease prevalence were correlated with parrotfish density, turbidity and water motion. Of these, a negative correlation with variability (SD) in turbidity explained most of the variability in PBTL prevalence (12.8%). A positive correlation with water motion explained 9% and a positive correlation with the variability in parrotfish density explained 4.4%. Overall, only a relatively small proportion of variability in PBTL prevalence could be explained by these three factors (26.2%), suggesting that other factors, not investigated in this study, play a more important role in explaining PBTL patterns or that temporal variation in temperature is the overall major driving force.  Monitoring of individually tagged P. compressa colonies showed that >80% of affected colonies sustained partial colony mortality (tissue loss) within two months; on average, one third of the colony is lost. The amount of tissue loss sustained was correlated to lesion size but not colony size. Case fatality (total mortality) was low (2.6%), however this disease can affect the same colonies repeatedly, suggesting a potential for progressive damage which could cause increased tissue loss over time. PBTL was not transmissible through direct contact or the water column in controlled aquaria experiments, suggesting that this disease might not be caused by a pathogen, is not highly infectious, or perhaps requires a vector for transmission. At present, PBTL has only been observed within Kaneohe Bay. An investigation of the potential role of host and Symbiodinium genetics in disease susceptibility revealed the same Symbiodinium sub-clade (C15) in healthy and PBTL-affected colonies, suggesting no involvement of Symbiodinium type in disease etiology. Results regarding host genetics remained inconclusive; however a difference in allele frequency at one microsatellite locus was observed between healthy and diseased samples. This difference could, however, be due to a lower amplification of PBTL-affected samples at this locus and needs to be regarded with some caution.  The results of this study provide a case definition of PBTL which can be used as a baseline in further studies. P. compressa is the main framework building species in Kaneohe Bay, and the information gathered here on disease dynamics and virulence suggests that PBTL has the potential to negatively impact the resilience of reefs within the bay. Further research into the etiology of PBTL is necessary to fully understand the impact that this disease could have on coral reefs in Hawaii.</p>

scholarly journals ­Inshore, turbid coral reefs from northwest Borneo exhibiting low diversity, but high cover show evidence of resilience to various environmental stressors

2018 ◽  
Author(s):  
Christina Brown ◽  
Nicola Browne ◽  
Jennifer L McIlwain ◽  
Jens Zinke
Keyword(s):  
Coral Reefs ◽  
Coral Cover ◽  
Synergistic Effects ◽  
Coral Disease ◽  
Sediment Accumulation ◽  
Land Development ◽  
Direct Result ◽  
Wet Season ◽  
Mucus Production ◽  
Hard Coral Cover

For reefs in SE Asia the synergistic effects of rapid land-development, insufficient environmental policies and a lack of enforcement has led to poor water quality and compromised coral health from increased sediment and pollution. Those inshore turbid coral reefs, subject to significant sediment inputs, may also inherit some resilience to the effects of thermal stress and coral bleaching. We studied the inshore turbid reefs near Miri, in northwest Borneo, through a comprehensive assessment of coral cover, health and function in addition to quantifying sediment-related parameters. Although Miri Reefs had comparatively low coral species diversity, dominated by massive and encrusting forms of Diploastrea, Porites, Montipora, Favites, Dipsastrea and Pachyseris, they were characterised by a healthy cover ranging from 22-39%. We found a strong inshore to offshore gradient in hard coral cover, diversity and community composition as a direct result of spatial differences in sediment but over scales of <10 km. As well as distance to shore, we included other environmental variables like reef depth and sediment accumulation/size that explained 62.5% of variation in benthic composition among sites. None of the reefs showed evidence of coral disease and relatively low prevalence of compromised health signs including bleaching (6.7%), bioerosion (6.6%), pigmentation (2.2%), scars (1.1%) and mucus production (0.5%). There were, however, seasonal differences in bioerosion rates which increased five-fold after the 2017 wet season. Tagged colonies of Diploastrea and Pachyseries showing partial bleaching in 2016, had fully recovered by 90-100% the following year. Differences in measures of coral function like that of symbiont density and chlorophyll a for Montipora, Pachyseris and Acropora were not detected among sites. This study provides further evidence that turbid coral reefs exposed to seasonally elevated sediment loads can exhibit relatively high coral cover and be resilient to disease and elevated sea surface temperatures.

scholarly journals Spatial variation in coral reef fish and benthic communities in the central Saudi Arabian Red Sea

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3410 ◽  
Author(s):  
Maha T. Khalil ◽  
Jessica Bouwmeester ◽  
Michael L. Berumen
Keyword(s):  
Spatial Variation ◽  
Red Sea ◽  
Marine Protected Area ◽  
Coral Cover ◽  
Benthic Communities ◽  
Saudi Arabian ◽  
Ongoing Research ◽  
Turf Algae ◽  
Top Predators ◽  
Thermal Bleaching

Local-scale ecological information is critical as a sound basis for spatial management and conservation and as support for ongoing research in relatively unstudied areas. We conducted visual surveys of fish and benthic communities on nine reefs (3–24 km from shore) in the Thuwal area of the central Saudi Arabian Red Sea. Fish biomass increased with increasing distance from shore, but was generally low compared to reefs experiencing minimal human influence around the world. All reefs had a herbivore-dominated trophic structure and few top predators, such as sharks, jacks, or large groupers. Coral cover was considerably lower on inshore reefs, likely due to a 2010 bleaching event. Community analyses showed inshore reefs to be characterized by turf algae, slower-growing corals, lower herbivore diversity, and highly abundant turf-farming damselfishes. Offshore reefs had more planktivorous fishes, a more diverse herbivore assemblage, and faster-growing corals. All reefs appear to be impacted by overfishing, and inshore reefs seem more vulnerable to thermal bleaching. The study provides a description of the spatial variation in biomass and community structure in the central Saudi Arabian Red Sea and provides a basis for spatial prioritization and subsequent marine protected area design in Thuwal.

scholarly journals Analisis Genus dan Penyakit Karang di Perairan Pulau Tuan Kecamatan Peukan Bada Kabupaten Aceh Besar

2017 ◽  
Vol 3 (2) ◽  
pp. 107 ◽  
Author(s):  
Nadia Aldyza ◽  
Afkar ,
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Survey Method ◽  
Coral Reef Ecosystem ◽  
Coral Diseases ◽  
Growth Anomalies ◽  
White Spots ◽  
Reef Ecosystem

This study aims to determine the genus of coral and coral diseases in the coral reef ecosystem of Tuan Island Peukan Bada, Aceh Besar District. The data of coral genera were gathered by using point intercept transect method, whereas, the data of coral diseases were gathered by using survey method. The data were identified by using handbook and then analyzed descriptively. The results showed that there were 5 coral genera found in Tuan Island Pekan Bada namely: Acropora, Montipora, Pocillopora, Porites, and Goniastrea. Meanwhile, coral diseases that are found in Tuan Island were ulcerative white spots, growth anomalies of an unknown cause, sediment damage, alga overgrowth, pink line disease dan pigmentation responses. The conclusion of this study were (1) the coral reefs that were found in Tuan Island Peukan Bada, Aceh Besar District consisted of 5 genera, and (2) coral diseases in Tuan Island consisted of 6 types of diseases.

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