The association between coral communities and disease assemblages in the Wakatobi Marine National Park, south-eastern Sulawesi, Indonesia

2015 ◽  
Vol 66 (10) ◽  
pp. 948 ◽  
Author(s):  
J. Haapkylä ◽  
J. Melbourne-Thomas ◽  
M. Flavell

The relationship between coral community structure and disease prevalence is poorly understood, particularly in the Coral Triangle. Improved understanding of this relationship will assist in identifying assemblages that might be particularly vulnerable to disease, and in predicting possible future impacts. Here, we report results from the last 2 years (2010 and 2011) of a 4-year coral disease-monitoring program (2005, 2007, 2010, 2011) in the Wakatobi Marine National Park (Indonesia), and evaluate changes in total disease prevalence and coral cover since 2005. A comparison with previously published results from 2005 and 2007 indicates that the number of coral diseases increased from two to eight and total disease prevalence tripled between 2005 and 2011. We observed a dramatic decline in coral cover and an increase in disease prevalence at a site with a unique community of foliose corals. However, because of the 3-year period between surveys (2007, 2010), it is likely that the peak of the disease event was not observed. While multi-year studies provide useful insights into the relationships between community structure and disease, our results emphasise how determining the drivers of change in remote reef locations is especially challenging if events such as disease outbreaks are missed.

2016 ◽  
Vol 64 (1) ◽  
pp. 79 ◽  
Author(s):  
Hansel Caballero Aragon ◽  
Pedro M Alcolado ◽  
Néstor Rey-Villiers ◽  
Susana Perera Valderrama ◽  
Juliett González Méndez

Wave exposure can influence community structure and distribution of shallow coral reefs, by affecting organisms both directly and indirectly. To assess the current stony coral community condition under different degrees of wave exposure at a marine protected area of the Gulf of Cazones (SW Cuba), two expeditions were carried out in May 2010 and June 2012. Four sampling sites were sampled at reef crests (1.5 m deep), and twelve at fore-reefs, at 10, 15 and 20 m deep in four geographic locations. Live coral cover, species richness and composition, colony density, and maximum diameter were assessed using the AGRRA 2001 methodology. Multivariate and non-parametric statistics were applied to compare sites. The coral community structure within reef crests was not homogenous. The observed variability of indicators apparently was determined by great coral mortality events resulting from natural disturbances that occurred in the past (hurricanes, bleaching and diseases). Fore-reef coral communities displayed better condition and lower coral mortality than reef crests. Species richness and coral composition varied, while multivariate and statistical methods did not reveal site grouping with regard to wave exposure. The remaining biological condition indicators were similar among sites, except in the most exposed one, where coral cover and coral size were slightly lower. Wave exposure in the gulf of Cazones seemed not to have a significant influence on differences in condition and structure of the assessed coral communities.


2011 ◽  
Vol 3 ◽  
pp. 51
Author(s):  
Hansel Caballero ◽  
Pedro M. Alcolado

Se evaluó la condición de la barrera de coral de los Bajos de Sancho Pardo (NW Cuba), área alejada de acciones antrópicas (excepto sobrepesca), pero que ha sufrido un período de frecuencia de huracanes, brotes de enfermedades y eventos de blanqueamiento de corales. En agosto del 2010 se aplicó la metodología de muestreo AGRRA en comunidades de corales de tres estaciones en las crestas, tres en las zonas traseras y 15 en el frente de arrecifes. Se identificaron 32 especies de corales, considerando solo colonias mayores de 10 cm de diámetro máximo. Los indicadores biológicos analizados sugieren cierta heterogeneidad en lascondiciones medioambientales y diferentes grados de resiliencia de los corales ante los disturbios naturales. El cubrimiento vivo medio de coral fue de 23% en las crestas, 27% en las zonas traseras y 9% en los arrecifes frontales. La densidad media lineal de corales fue de 8 colonias/10 m en las crestas, 11 colonias/10 m en las zonas traseras y 5 colonias/10 m en los arrecifes frontales. Se observó mortalidad reciente por enfermedades activas. La mortalidad antigua fue mayor en las zonas traseras y en las crestas, a causa aparentementede la mayor influencia de los huracanes por la menor profundidad. Los arrecifes estuvieron perturbados por cubrimiento importante de algas carnosas supuestamente por un insuficiente nivel de herbivorismo. ABSTRACT The condition of the barrier reef in Bajos de Sancho Pardo (NW Cuba) was assessed. This area is located far from anthropogenic disturbances (except overfishing) and has suffered a period of frequent hurricanes, coral disease outbreaks, and coral bleaching events. In August 2010, the AGRRA sampling methodology was applied to 21 coral communities;three crest stations, three rear zones, and 15 fore reef stations. Thirty-two coral species were identified, considering only colonies larger than 10 cm maximum diameter. The biological indicators analyzed suggest some degree of heterogeneity of environmental conditions and different levels of coral resiliency to natural disturbances. Average live coral cover was 23% on reef crests, 27% on back reefs and 9% on fore reefs. Average coral linear density was 8 colonies/10 m on reef crests, 11 colonies/10 m on back reefs and 5 colonies/10 m on fore reefs. Recent mortality was observed resulting from active diseases. Old mortality was higher in back reefs and reef crests, apparently due to the higher influence of hurricanes due to their shallow depths. Reefs were disturbed by a significant fleshy algae cover provably due to low levels of herbivory.


2021 ◽  
Vol 8 ◽  
Author(s):  
Benjamin Weitzman ◽  
Brenda Konar ◽  
Katrin Iken ◽  
Heather Coletti ◽  
Daniel Monson ◽  
...  

Marine heatwaves are global phenomena that can have major impacts on the structure and function of coastal ecosystems. By mid-2014, the Pacific Marine Heatwave (PMH) was evident in intertidal waters of the northern Gulf of Alaska and persisted for multiple years. While offshore marine ecosystems are known to respond to these warmer waters, the response of rocky intertidal ecosystems to this warming is unclear. Intertidal communities link terrestrial and marine ecosystems and their resources are important to marine and terrestrial predators and to human communities for food and recreation, while simultaneously supporting a growing coastal tourism industry. Given that current climate change projections suggest increased frequency and duration of marine heatwaves, monitoring and understanding the impacts of heatwaves on intertidal habitats is important. As part of the Gulf Watch Alaska Long-Term Monitoring program, we examined rocky intertidal community structure at 21 sites across four regions spanning 1,200 km of coastline: Western Prince William Sound, Kenai Fjords National Park, Kachemak Bay, and Katmai National Park and Preserve. Sites were monitored annually from 2012 to 2019 at mid and low tidal strata. Before-PMH (2012–2014), community structure differed among regions. We found macroalgal foundation species declined during this period mirroring patterns observed elsewhere for subtidal habitat formers during heatwave events. The region-wide shift from an autotroph-macroalgal dominated rocky intertidal to a heterotroph-filter-feeder dominated state concurrent with the changing environmental conditions associated with a marine heatwave event suggests the PMH had Gulf-wide impacts to the structure of rocky intertidal communities. During/after-PMH (2015–2019), similarities in community structure increased across regions, leading to a greater homogenization of these communities, due to declines in macroalgal cover, driven mostly by a decline in the rockweed, Fucus distichus, and other fleshy red algae in 2015, followed by an increase in barnacle cover in 2016, and an increase in mussel cover in 2017. Strong, large-scale oceanographic events, like the PMH, may override local drivers to similarly influence patterns of intertidal community structure.


2014 ◽  
Author(s):  
James R Guest ◽  
Jeffrey Low ◽  
Karenne Tun ◽  
Jani I Tanzil ◽  
Peter A Todd ◽  
...  

Projected increases in the magnitude and frequency of sea surface temperature anomalies present a significant threat to the persistence of tropical coral reefs, however, detailed studies of community level responses to thermal stress are needed if its effect on reef resilience are to be understood. While many studies report on broad, regional scale responses to thermal stress (e.g., proportion of corals bleached), far fewer examine variation in susceptibility among taxa and change in coral community structure, before, during and after bleaching on individual reefs. Furthermore, relatively few studies of bleaching response come from highly urbanised reefs that experience chronic disturbances such as elevated sedimentation and turbidity. Here we report in detail on the bleaching response of corals at a highly urbanised reef site south of mainland Singapore during (June, July) and immediately after (October) a major thermal coral bleaching event in 2010. To estimate the capacity for resistance and resilience to thermal stress, we report on a) the overall bleaching severity during and after the event, b) differences in bleaching susceptibility among taxa during the event and c) the response of the reef in terms of taxonomic community structure before (2009) and after (2012) bleaching. Despite severe bleaching in 2010 (66% of colonies bleached), post-bleaching recovery appeared to be relatively rapid and coral taxa that are usually highly susceptible (e.g., Acropora and Pocillopora) were relatively unaffected, i.e., either they did not bleach or they bleached and recovered. Although there was no significant change in coral taxonomic community structure among years, taxa that bleached most severely tended to have the greatest reductions in relative cover. Several factors may have contributed to the overall high resistance of this site to bleaching including turbidity, symbiont affiliation and heterotrophy. A parsimonious explanation for the reversed pattern of bleaching susceptibility among taxa is that these coral populations have adapted and/or acclimatised to thermal stress. Despite ongoing chronic anthropogenic impacts, we suggest that this site has potential for rapid recovery of coral cover due to the dominant coral taxa and growth forms being capable of rapid regrowth from remnant colonies.


2020 ◽  
Vol 12 (21) ◽  
pp. 9052
Author(s):  
Yu-Rong Cheng ◽  
Chi-Hsiang Chin ◽  
Ding-Fa Lin ◽  
Chao-Kang Wang

In recent decades, coral reefs worldwide have been impacted annually by climate change and anthropogenic impacts. Marine parks are utilized to protect coral reef ecosystems and to ensure it is in sustainable use. In the present study, a 15-year change in coverage and composition of a hard coral community at Dongsha Atoll Marine National Park (DAMNP) was examined from 2005 to 2019. The reef has experienced several disturbances, including 11 typhoons and six coral bleaching events. A 34.39% decline in coral coverage had been recorded over the past 15 years in response to multiple and recurrent natural disturbances. The coral communities and functional ecology of the Dongsha Atoll changed during this period. The average dissimilarities in coral communities ranged from 55.38 to 59.02%. The dramatic decrease in the abundance of branching corals in addition to a slight increase in massive and encrusting corals suggest the habitat has simplified. The degraded coral reef communities represent a low resilience ecosystem, even though the DAMNP has been established. Without effective management, the coral reef ecosystem of the Dongsha Atoll may not persist due to repeated impacts from recurrent disturbances.


Author(s):  
Lorenzo Alvarez-Filip ◽  
Nuria Estrada-Saldívar ◽  
Esmeralda Pérez-Cervantes ◽  
Ana Molina-Hernández ◽  
Francisco J. Gonzalez-Barrios

Caribbean reef corals have experienced unprecedented declines from climate change, anthropogenic stressors and infectious diseases in recent decades. Since 2014 a highly lethal, new disease, called stony coral tissue loss disease (SCTLD), has impacted many species in Florida. During the summer of 2018 we noticed an anomalously high disease prevalence affecting different coral species in the northern portion of the Mexican Caribbean. We assessed the severity of this outbreak in 2018/2019 using the AGRRA coral protocol to survey 82 reef sites across the Mexican Caribbean. Then, using a subset of 14 sites we detailed information from before the outbreak (2016/2017) to explore the consequences of the disease on the condition and composition of coral communities. Our findings show that the disease outbreak has already spread across the entire region, affecting similar species (with similar disease patterns) to those previously described for Florida. However, we observed a great variability in prevalence and tissue mortality that was not attributable to any geographical gradient. Using long-term data, we determined that there is no evidence of such high coral disease prevalence anywhere in the region before 2018, which suggests that the entire Mexican Caribbean (~450 km) was afflicted by the disease within a few months. The analysis of sites that contained pre-outbreak information showed that this event considerably increased coral mortality and severely changed the structure of coral communities in the region. Given the high prevalence and lethality of this disease, and the high number of susceptible species, we encourage reef researchers, managers and stakeholders across the Western Atlantic to accord it the highest priority for the near future.


2021 ◽  
Vol 8 ◽  
Author(s):  
Graham Kolodziej ◽  
Michael S. Studivan ◽  
Arthur C. R. Gleason ◽  
Chris Langdon ◽  
Ian C. Enochs ◽  
...  

Since the appearance of stony coral tissue loss disease (SCTLD) on reefs off Miami in 2014, this unprecedented outbreak has spread across the entirety of Florida’s coral reef tract, as well as to many territories throughout the Caribbean. The endemic zone reached the upper Florida Keys by 2016, resulting in partial or complete mortality of coral colonies across numerous species. Disease was first observed at Cheeca Rocks (Islamorada, Florida) in the beginning of 2018, with reports of coral mortality peaking mid-year. The disease was still present at Cheeca Rocks as of March 2020, however, to a lesser degree compared to the initial outbreak. Annual monitoring efforts have been ongoing at Cheeca Rocks since 2012, including repeated benthic photomosaics of a 330 m2 survey zone, spanning six replicate sites. As such, a repository of coral community composition data exists for before and after the disease outbreak that was analyzed to assess the impacts of SCTLD on reef communities at an upper Florida Keys inshore reef. Cheeca Rocks is hypothesized to be a resilient reef due to its persistent high coral cover despite its inshore location, which subjects corals to fluctuating water quality and marginal environmental conditions. Coral populations here have been shown to recover from bleaching events and heat stress with minimal coral mortality. Though colonies of coral species characterized as highly and moderately susceptible to SCTLD (e.g., Colpophyllia natans, Diploria labyrinthiformis, Pseudodiploria strigosa, Orbicella annularis, and O. faveolata) suffered mortality as a result of the outbreak with an average loss of 16.42% relative cover by species, the overall impacts on coral cover and community structure were relatively low, contributing to a loss of total coral cover of only 1.65%. Comparison of photomosaic data to other studies indicate Cheeca Rocks may not have been affected as severely as other sites on Florida’s coral reef tract, underlying this site’s potential role in coral resilience to stressors including bleaching events, land-based pollution, and disease epizootics.


Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 486
Author(s):  
Radonirina Lebely Botosoamananto ◽  
Gildas Todinanahary ◽  
Andriamanjato Razakandrainy ◽  
Mahery Randrianarivo ◽  
Lucie Penin ◽  
...  

The Great Reef of Toliara, on the southwestern coast of Madagascar, has been documented as harbouring flourishing reef communities in the 1960s, but has since been affected by various threats, causing a coral decline last reported in 2008. In 2017, we examined the spatial heterogeneity in coral community structure in the region of Toliara. Coral assemblages were characterized by a marked spatial variability, with significant variation for most of the descriptors among the three major habitats and also among stations within habitats. We recorded high coral cover, with values >40% at six of the 10 stations, which was associated with high abundance of coral colonies. We also documented the return to an Acropora-dominated coral assemblage. While these positive results suggest a recent return to healthier coral assemblages, they must be tempered, as the diversity that we recorded was lower than in the 1960s. Moreover, we found a high cover of algae at several stations, suggesting that the ecosystem is likely close to the tipping point toward a phase shift. Finally, the population size-structure of major coral taxa was positively skewed, with few large colonies to ensure the replenishment of local populations. The marked spatial variation suggests that marine protected areas should integrate a sufficiently large area to capture the scale of this spatial heterogeneity.


2021 ◽  
Vol 8 ◽  
Author(s):  
Erick Barrera-Falcon ◽  
Rodolfo Rioja-Nieto ◽  
Roberto C. Hernández-Landa ◽  
Edgar Torres-Irineo

The precise assessing and monitoring of coral reefs are necessary to address and understand the threats and changes in coral communities. With the development of new technologies and algorithms for image processing, new protocols like underwater photogrammetry are implemented to study these ecosystems. This study compares the main ecological metrics for reef condition assessment, obtained with an underwater digital photogrammetry protocol (UWP) and traditional sampling design simulations in coral reefs of the Cozumel Reefs National Park. Three orthomosaics (380 m2) per reef on six fringing reefs were constructed, and the hard coral community characterized using a Geographic Information System (GIS). The orthomosaics were also used as a basis to simulate transect lines and obtain data on the hard coral community according to the video transect (VT) protocol, point intercept (PIT) protocol, and the Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol. Higher colony abundance, species richness, and lower coral cover estimates (p < 0.05) were obtained with the UWP. This protocol was also sensitive to small sized species. All the sampling designs showed similar capability to identify dominant species in terms of colony abundance and coral cover. The VT, PIT, and AGGRA showed similar coral cover values (p > 0.05), which seems to indicate that these sampling designs overestimate this important metric. Our results will help to understand and integrate the observations obtained with UWP with long-term data obtained with commonly used monitoring protocols in the Caribbean region.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6006 ◽  
Author(s):  
Eric Jordán-Dahlgren ◽  
Adán G. Jordán-Garza ◽  
Rosa E. Rodríguez-Martínez

In the last decades diseases have changed coral communities’ structure and function in reefs worldwide. Studies conducted to evaluate the effect of diseases on corals frequently use modified adaptations of sampling designs that were developed to study ecological aspects of coral reefs. Here we evaluate how efficient these sampling protocols are by generating virtual data for a coral population parameterized with mean coral density and disease prevalence estimates from the Caribbean scleractinian Orbicella faveolata at the Mexican Caribbean. Six scenarios were tested consisting of three patterns of coral colony distribution (random, randomly clustered and randomly over-dispersed) and two disease transmission modes (random and contagious). The virtual populations were sampled with the commonly used method of belt-transects with variable sample-unit sizes (10 × 1, 10 × 2, 25 × 2, 50 × 2 m). Results showed that the probability of obtaining a mean coral disease prevalence estimate of ±5% of the true prevalence value was low (range: 11–48%) and that two-sample comparisons achieved rather low power, unless very large effect sizes existed. Such results imply low statistical confidence to assess differences or changes in coral disease prevalence. The main problem identified was insufficient sample size because local mean colony size, density and spatial distribution of targeted coral species was not taken into consideration to properly adjust the sampling protocols.


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