scholarly journals Widespread loss of Caribbean acroporid corals was underway before coral bleaching and disease outbreaks

2020 ◽  
Vol 6 (17) ◽  
pp. eaax9395 ◽  
Author(s):  
Katie L. Cramer ◽  
Jeremy B. C. Jackson ◽  
Mary K. Donovan ◽  
Benjamin J. Greenstein ◽  
Chelsea A. Korpanty ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Population ◽  
Human Impacts ◽  
Coral Disease ◽  
Disease Outbreaks ◽  
Acropora Palmata ◽  
Acropora Cervicornis ◽  
The Caribbean ◽  
The 1960S ◽  
Agricultural Areas

The mass mortality of acroporid corals has transformed Caribbean reefs from coral- to macroalgal-dominated habitats since systematic monitoring began in the 1970s. Declines have been attributed to overfishing, pollution, sea urchin and coral disease, and climate change, but the mechanisms are unresolved due to the dearth of pre-1970s data. We used paleoecological, historical, and survey data to track Acropora presence and dominance throughout the Caribbean from the prehuman period to present. Declines in dominance from prehuman values first occurred in the 1950s for Acropora palmata and the 1960s for Acropora cervicornis, decades before outbreaks of acroporid disease or bleaching. We compared trends in Acropora dominance since 1950 to potential regional and local drivers. Human population negatively affected and consumption of fertilizer for agriculture positively affected A. palmata dominance, the latter likely due to lower human presence in agricultural areas. The earlier, local roots of Caribbean Acropora declines highlight the urgency of mitigating local human impacts.

scholarly journals Symbiotic immuno-suppression: is disease susceptibility the price of bleaching resistance?

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4494 ◽  
Author(s):  
Daniel G. Merselis ◽  
Diego Lirman ◽  
Mauricio Rodriguez-Lanetty
Keyword(s):  
Climate Change ◽  
Disease Susceptibility ◽  
Disease Outbreaks ◽  
Significant Negative Correlation ◽  
South Florida ◽  
Anthropogenic Climate Change ◽  
Acropora Cervicornis ◽  
Coral Mortality ◽  
The Caribbean ◽  
Immunological Protection

Accelerating anthropogenic climate change threatens to destroy coral reefs worldwide through the processes of bleaching and disease. These major contributors to coral mortality are both closely linked with thermal stress intensified by anthropogenic climate change. Disease outbreaks typically follow bleaching events, but a direct positive linkage between bleaching and disease has been debated. By tracking 152 individual coral ramets through the 2014 mass bleaching in a South Florida coral restoration nursery, we revealed a highly significant negative correlation between bleaching and disease in the Caribbean staghorn coral,Acropora cervicornis. To explain these results, we propose a mechanism for transient immunological protection through coral bleaching: removal ofSymbiodiniumduring bleaching may also temporarily eliminate suppressive symbiont modulation of host immunological function. We contextualize this hypothesis within an ecological perspective in order to generate testable predictions for future investigation.

scholarly journals Experimental antibiotic treatment identifies potential pathogens of white band disease in the endangered Caribbean coral Acropora cervicornis

2014 ◽  
Vol 281 (1788) ◽  
pp. 20140094 ◽  
Author(s):  
M. J. Sweet ◽  
A. Croquer ◽  
J. C. Bythell
Keyword(s):  
Coral Disease ◽  
Causal Agent ◽  
Acropora Palmata ◽  
Acropora Cervicornis ◽  
Coral Diseases ◽  
White Band ◽  
Disease Causation ◽  
Community Shifts ◽  
White Band Disease ◽  
Experimental Treatments

Coral diseases have been increasingly reported over the past few decades and are a major contributor to coral decline worldwide. The Caribbean, in particular, has been noted as a hotspot for coral disease, and the aptly named white syndromes have caused the decline of the dominant reef building corals throughout their range. White band disease (WBD) has been implicated in the dramatic loss of Acropora cervicornis and Acropora palmata since the 1970s, resulting in both species being listed as critically endangered on the International Union for Conservation of Nature Red list. The causal agent of WBD remains unknown, although recent studies based on challenge experiments with filtrate from infected hosts concluded that the disease is probably caused by bacteria. Here, we report an experiment using four different antibiotic treatments, targeting different members of the disease-associated microbial community. Two antibiotics, ampicillin and paromomycin, arrested the disease completely, and by comparing with community shifts brought about by treatments that did not arrest the disease, we have identified the likely candidate causal agent or agents of WBD. Our interpretation of the experimental treatments is that one or a combination of up to three specific bacterial types, detected consistently in diseased corals but not detectable in healthy corals, are likely causal agents of WBD. In addition, a histophagous ciliate ( Philaster lucinda ) identical to that found consistently in association with white syndrome in Indo-Pacific acroporas was also consistently detected in all WBD samples and absent in healthy coral. Treatment with metronidazole reduced it to below detection limits, but did not arrest the disease. However, the microscopic disease signs changed, suggesting a secondary role in disease causation for this ciliate. In future studies to identify a causal agent of WBD via tests of Henle–Koch's postulates, it will be vital to experimentally control for populations of the other potential pathogens identified in this study.

scholarly journals Twenty years of change in benthic communities across the Belizean Barrier Reef

2021 ◽  
Author(s):  
John F Bruno ◽  
Catherine Alves ◽  
Richard B. Aronson ◽  
Nadia Bood ◽  
Karl D. Castillo ◽  
...  
Keyword(s):  
Community Composition ◽  
Human Impacts ◽  
Coral Cover ◽  
Benthic Communities ◽  
Disease Outbreaks ◽  
Barrier Reef ◽  
Living Coral ◽  
The Caribbean ◽  
And Shifts ◽  
Benthic Composition

Disease, ocean warming, and pollution have caused catastrophic declines in the cover of living coral on reefs across the Caribbean. Subsequently, reef-building corals have been replaced by invertebrates and macroalgae, leading to changes in ecological functioning. We describe changes in benthic community composition and cover at 15 sites across the Belizean Barrier Reef (BBR) following numerous major disturbances—bleaching, storms, and disease outbreaks—over the 20-year period 1997–2016. We tested the role of potential drivers of change on coral reefs, including local human impacts and ocean temperature. From 1997 to 2016, mean coral cover significantly declined from 26.3% to 10.7%, while macroalgal cover significantly increased from 12.9% to 39.7%. We documented a significant decline over time of the reef-building corals Orbicella spp. and described a major shift in benthic composition between early sampling years (1997–2005) and later years (2009¬–2016). The covers of hard-coral taxa, including Acropora spp., M. cavernosa, Orbicella spp., and Porites spp., were negatively related to marine heatwave frequency. Only gorgonian cover was related, negatively, to our metric of the magnitude of local impacts (the Human Influence Index). Changes in benthic composition and cover were not associated with local protection or fishing. This result is concordant with studies throughout the Caribbean that have documented living coral decline and shifts in reef-community composition following disturbances, regardless of local fisheries restrictions. Our results suggest that benthic communities along the BBR have experienced disturbances that are beyond the capacity of the current management structure to mitigate. We recommend that managers devote greater resources and capacity to enforce and expand existing marine protected areas and that government, industry, and the public act to reduce global carbon emissions.

Threats to terrestrial biodiversity

2019 ◽  
pp. 177-212
Author(s):  
Richard T. Corlett
Keyword(s):  
Climate Change ◽  
Human Population ◽  
Human Impacts ◽  
Emerging Infectious Diseases ◽  
Forest Products ◽  
Wildlife Trade ◽  
Infrastructure Development ◽  
Non Timber Forest Products ◽  
Negative Impacts ◽  
Terrestrial Biodiversity

More than a billion people inhabit Tropical East Asia today and negative impacts on ecosystems and wild species are pervasive. Historically, the ultimate driver has been human population growth, but while this is now slowing, there is no prospect of an early reduction in human impacts. Poverty, corruption, weak governance, and globalization are additional underlying drivers. The major proximal threats and their consequences—deforestation, habitat fragmentation, mining, urbanization and infrastructure development, logging and the collection of non-timber forest products, hunting and the wildlife trade, fires, invasive species, emerging infectious diseases, air pollution and nutrient enrichment, and anthropogenic climate change—are described in turn in this chapter. Finally, the problems of assessing and predicting extinctions are discussed.

scholarly journals Extinction in Eden: identifying the role of climate change in the decline of the koala in south-eastern NSW

2014 ◽  
Vol 41 (1) ◽  
pp. 22 ◽  
Author(s):  
Daniel Lunney ◽  
Eleanor Stalenberg ◽  
Truly Santika ◽  
Jonathan R. Rhodes
Keyword(s):  
Climate Change ◽  
Survey Data ◽  
Habitat Loss ◽  
Human Population ◽  
Human Impacts ◽  
Population Analysis ◽  
Community Survey ◽  
South Eastern ◽  
South Wales ◽  
Change Temperature

Context Reviews of climate change in Australia have identified that it is imposing additional stresses on biodiversity, which is already under threat from multiple human impacts. Aims The present study aimed to determine the contributions of several factors to the demise of the koala in the Eden region in south-eastern New South Wales and, in particular, to establish to what extent climate change may have exacerbated the decline. Methods The study built on several community-based koala surveys in the Eden region since 1986, verified through interviews with survey respondents. Historical records as far back as the late 19th century, wildlife databases and field-based surveys were used to independently validate the community survey data and form a reliable picture of changes in the Eden koala population. Analysis of the community survey data used a logistic model to assess the contribution of known threats to koalas, including habitat loss measured as changes in foliage projective cover, fire, increases in the human population and climate change in the form of changes in temperature and rainfall, to the regional decline of this species. Key results We found a marked, long-term shrinkage in the distribution of the koala across the Eden region. Our modelling demonstrated that a succession of multiple threats to koalas from land use (human population growth and habitat loss) and environmental change (temperature increase and drought) were significant contributors to this decline. Conclusions Climate change, particularly drought and rising temperatures, has been a hitherto hidden factor that has been a major driver of the decline of the koala in the Eden region. Implications Development of strategies to help fauna adapt to the changing climate is of paramount importance, particularly at a local scale.

scholarly journals High clonality in Acropora palmata and Acropora cervicornis populations of Guadeloupe, French Lesser Antilles

2015 ◽  
Vol 66 (9) ◽  
pp. 847 ◽  
Author(s):  
A. Japaud ◽  
C. Bouchon ◽  
J.-L. Manceau ◽  
C. Fauvelot
Keyword(s):  
Genetic Diversity ◽  
Clonal Growth ◽  
Caribbean Sea ◽  
Lesser Antilles ◽  
Acropora Palmata ◽  
Acropora Cervicornis ◽  
Population Densities ◽  
Genetic Status ◽  
The Caribbean ◽  
Genotypic Richness

Since the 1980s, population densities of Acroporidae have dramatically declined in the Caribbean Sea. Quantitative censuses of Acroporidae provide information on the number of colonies (i.e. ramets), but not on the number of genetically distinct individuals (i.e. genets). In this context, the aim of our study was to provide an overview of the genetic status of Acropora populations in Guadeloupe by examining the genotypic richness of Acropora palmata and Acropora cervicornis. Using 14 microsatellite loci, we found extremely low genotypic richness for both species from Caye-à-Dupont reef (i.e. 0.125 for A. palmata and nearly zero for A. cervicornis). Because genetic diversity contributes to the ability of organisms to evolve and adapt to new environmental conditions, our results are alarming in the context of ongoing global warming as long periods of clonal growth without sexual recruitment may lead to the extinction of these populations.

scholarly journals Growth dynamics in Acropora cervicornis and A. prolifera in southwest Puerto Rico

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8435 ◽  
Author(s):  
Ernesto Weil ◽  
Nicholas M. Hammerman ◽  
Rebecca L. Becicka ◽  
Juan Jose Cruz-Motta
Keyword(s):  
Puerto Rico ◽  
Disease Outbreaks ◽  
Growth Dynamics ◽  
Medium Size ◽  
Acropora Palmata ◽  
Acropora Cervicornis ◽  
Storm Damage ◽  
Quick Recovery ◽  
Natural Reserve ◽  
La Parguera

Natural population recovery of Acropora palmata, A. cervicornis and their hybrid, Acropora prolifera, have fluctuated significantly after their Caribbean-wide, disease-induced mass mortality in the early 1980s. Even though significant recovery has been observed in a few localities, recurrent disease outbreaks, bleaching, storm damage, local environmental deterioration, algae smothering, predation, low sexual recruitment and low survivorship have affected the expected, quick recovery of these weedy species. In this study, the status of three recovering populations of A. cervicornis and two of A. prolifera were assessed over one year using coral growth and mortality metrics, and changes in their associated algae and fish/invertebrate communities in three localities in the La Parguera Natural Reserve (LPNR), southwest coast of Puerto Rico. Five branches were tagged in each of 29, medium size (1–2 m in diameter) A. cervicornis and 18 A. prolifera colonies in the Media Luna, Mario and San Cristobal reefs off LPNR. Branches were measured monthly, together with observations to evaluate associated disease(s), algae accumulation and predation. A. cervicornis grew faster [3.1 ± 0.44 cm/month (= 37.2 cm/y)] compared to A. prolifera [2.6 ± 0.41 cm/month (= 31.2 cm/y)], and growth was significantly higher during Winter-Spring compared to Summer-Fall for both taxa (3.5 ± 0.58 vs. 0.53 ± 0.15 cm/month in A. cervicornis, and 2.43 ± 0.71 vs. 0.27 ± 0.20 cm/month in A. prolifera, respectively). Algal accumulation was only observed in A. cervicornis, and was higher during Spring-Summer compared to Fall-Winter (6.1 ± 0.91 cm/month and 3.8 ± 0.29 cm/month, respectively, (PERMANOVA, df = 2, MS = 10.2, p = 0.37)). Mortality associated with white band disease, algae smothering and fish/invertebrate predation was also higher in A. cervicornis and varied among colonies within sites, across sites and across season. The balance between tissue grow and mortality determines if colonies survive. This balance seems to be pushed to the high mortality side often by increasing frequency of high thermal anomalies, inducing bleaching and disease outbreaks and other factors, which have historically impacted the natural recovery of these taxa in the La Parguera Natural Reserve in Puerto Rico and possibly other areas in the region. Overall, results indicate variability in both growth and mortality rates in both taxa across localities and seasons, with A. cervicornis showing overall higher mortalities compared to A. prolifera.

scholarly journals A standard field protocol for testing relative disease resistance in Acropora palmata and Acropora cervicornis

2016 ◽  
Author(s):  
Margaret W Miller ◽  
Dana E Williams
Keyword(s):  
Disease Resistance ◽  
Coral Species ◽  
Coral Disease ◽  
Acropora Palmata ◽  
Acropora Cervicornis ◽  
Nursery Culture ◽  
Standard Field ◽  
Resistance Traits

Coral disease has been identified as an ongoing threat to the recovery of sustainable coral populations. This document provides a standard field protocol for screening disease resistance traits in the imperiled coral species, Acropora palmata and Acropora cervicornis, particularly genotypes under nursery culture for population enhancement. It is intended to be implemented by practitioners and researchers in coral restoration and provide standardized information on disease resistance that can aid in the design and success of population enhancement efforts.

scholarly journals A standard field protocol for testing relative disease resistance in Acropora palmata and Acropora cervicornis

2016 ◽  
Author(s):  
Margaret W Miller ◽  
Dana E Williams
Keyword(s):  
Disease Resistance ◽  
Coral Species ◽  
Coral Disease ◽  
Acropora Palmata ◽  
Acropora Cervicornis ◽  
Nursery Culture ◽  
Standard Field ◽  
Resistance Traits

Coral disease has been identified as an ongoing threat to the recovery of sustainable coral populations. This document provides a standard field protocol for screening disease resistance traits in the imperiled coral species, Acropora palmata and Acropora cervicornis, particularly genotypes under nursery culture for population enhancement. It is intended to be implemented by practitioners and researchers in coral restoration and provide standardized information on disease resistance that can aid in the design and success of population enhancement efforts.

scholarly journals Shifting white pox aetiologies affecting Acropora palmata in the Florida Keys, 1994–2014

2016 ◽  
Vol 371 (1689) ◽  
pp. 20150205 ◽  
Author(s):  
Kathryn P. Sutherland ◽  
Brett Berry ◽  
Andrew Park ◽  
Dustin W. Kemp ◽  
Keri M. Kemp ◽  
...  
Keyword(s):  
Coral Disease ◽  
Bacterial Pathogen ◽  
Florida Keys ◽  
Disease State ◽  
Moving Target ◽  
Acropora Palmata ◽  
Coral Diseases ◽  
Disease Aetiology ◽  
The Caribbean

We propose ‘the moving target hypothesis’ to describe the aetiology of a contemporary coral disease that differs from that of its historical disease state. Hitting the target with coral disease aetiology is a complex pursuit that requires understanding of host and environment, and may lack a single pathogen solution. White pox disease (WPX) affects the Caribbean coral Acropora palmata . Acroporid serratiosis is a form of WPX for which the bacterial pathogen ( Serratia marcescens ) has been established. We used long-term (1994–2014) photographic monitoring to evaluate historical and contemporary epizootiology and aetiology of WPX affecting A. palmata at eight reefs in the Florida Keys. Ranges of WPX prevalence over time (0–71.4%) were comparable for the duration of the 20-year study. Whole colony mortality and disease severity were high in historical (1994–2004), and low in contemporary (2008–2014), outbreaks of WPX. Acroporid serratiosis was diagnosed for some historical (1999, 2003) and contemporary (2012, 2013) outbreaks, but this form of WPX was not confirmed for all WPX cases. Our results serve as a context for considering aetiology as a moving target for WPX and other coral diseases for which pathogens are established and/or candidate pathogens are identified. Coral aetiology investigations completed to date suggest that changes in pathogen, host and/or environment alter the disease state and complicate diagnosis.

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