The symbiotic sea anemone Exaiptasia diaphana (Aiptasia) is a model organism used to better understand cnidarian-algal symbiosis and coral bleaching (dysbiosis). Many biological processes are hypothesized to be involved in coral dysbiosis, and the innate immunity is a key area of interest. Rab proteins are small proteins with GTPase domains,...
Corals provide a diversity of ecosystem services, are among the most biologically diverse ecosystems on Earth, and directly support ~500 million people globally; however, corals are increasingly experiencing significant threats and are undergoing severe bleaching events as the result of the warming climate. Using a two-year data set surrounding a...
Many members of the Phylum Cnidaria are mutualistic with unicellular dinoflagellates belonging to the genus Symbiodinium. Corals are the most widely recognized example of these associations due to their key ecological importance in coral reef ecosystems where they serve as the structural and trophic foundation of these rich ecosystems. Coral...
Corals have multiple roles in maintaining ocean health and are some of the world’s most diverse ecosystems. The coral animal is host to a multitude of taxa, including symbiotic dinoflagellate algae, fungi, bacteria, protists, and viruses. Environmental stressors and disease agents can perturb the delicate balance of the coral host...
Coral reefs have become extremely vulnerable to rising ocean temperatures, with mass bleaching events increasing in frequency and severity. If bleaching events persist annually, models predict that more than 90% of reef species will face long-term degradation. However, recent evidence has shown that corals may be able to thermally acclimate...
Cnidarians, such as anemones and corals, engage in an intracellular symbiosis with
photosynthetic dinoflagellates. Corals form both the trophic and structural foundation of
reef ecosystems. Despite their environmental importance, little is known about the
molecular basis of this symbiosis. In this dissertation we explored the cnidariandinoflagellate symbiosis from two perspectives:...
Previous studies of coral viruses have employed either microscopy or metagenomics, but few have attempted to comprehensively link the presence of a virus-like particle (VLP) to a genomic sequence. We conducted transmission electron microscopy imaging and virome analysis in tandem to characterize the most conspicuous viral types found within the...
Rapid assessments are essential to establish baseline information of ecosystems that can
be used to design management plans such as marine protected areas. A rapid ecological
assessment was conducted to determine the conditions of coral reefs and reef fish around barrier islands that occur within the central Belize Barrier Reef...
Experimental manipulation of the symbiosis between cnidarians and photosynthetic dinoflagellates (Symbiodinium spp.) is crucial to advancing the understanding of the cellular mechanisms involved in host-symbiont interactions, and overall coral reef ecology. The anemone Aiptasia sp. is a model for cnidarian-dinoflagellate symbiosis, and notably it can be rendered aposymbiotic (i.e. dinoflagellate-free)...
Understanding the processes that influence the composition of animal communities is a central goal in ecology. Interactions between established residents and colonizing juveniles that affect the subsequent survival of juveniles may influence community composition. In a series of experiments on coral reef fish communities in the Bahamas and Australia, I...
Coral reef ecosystems are the oceanic equivalent of tropical rainforests, in terms of biodiversity. The estimated 1,037,000 square kilometers worldwide of reef provide
habitat for over one million species of plants and animals (Hinrichsen, 1997). Coral reefs are important to the economy of coastal nations because of the fisheries and...
In host-associated microbiomes, the mechanisms that regulate community composition or the principles that govern dynamics remain far from clear. However, understanding how the structure of microbial communities shift as the system moves away from a healthy state is critical to assessing disease progression and to formulate any potential mitigation strategy....
In September of 2010, Brewer's Bay reef, located in St. Thomas (U.S. Virgin Islands), was simultaneously affected by abnormally high temperatures and the passage of a hurricane that resulted in the mass bleaching and fragmentation of its coral community. An outbreak of a rapid tissue loss disease among coral colonies...
Coral reefs are in decline worldwide, and land-derived sources of pollution, including sewage, are a major force driving that deterioration. This review presents evidence that sewage discharge occurs in waters surrounding at least 104 of 112 reef geographies. Studies often refer to sewage as a single stressor. However, we show...
Seagrasses and coral reefs play important roles in nutrient cycling, coastal protection, and maintaining marine biodiversity. However, these coastal marine organisms are declining globally due to anthropogenic stressors, such as rising ocean temperatures, ocean acidification, and eutrophication. These organisms live in close association with their microbiomes, which can be beneficial...
Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental...
Mutualistic associations between cnidarians, such as corals, and photosynthetic
dinoflagellate algae provide the trophic and structural foundation of coral reef
ecosystems. In many cases, this intracellular mutualism is highly specific and must be
established anew for each generation of host corals. The ability to maintain partner
specificity across generations implies...
As important ecological cornerstones, coral reefs face threats from a myriad of sources, such as global climate change, and importantly, disease, the latter often as a result of microbial pathogens. An understudied group of major corals, fire corals, and their even less understood microbiome present an opportunity to learn more...
Climate change is causing the world’s oceans to increase in temperature, threatening many populations of organisms. Corals are of particular concern, due to both their ecological importance and sensitivity to high temperatures. Coral populations in the Persian Gulf, however, have been surviving in normally-lethal thermal conditions. An analysis of specific...
Stony corals are the ecosystem engineers of the vital, dynamic, and complex marine ecosystem known as coral reefs. Globally, coral reefs are undergoing degradation from multiple anthropogenic stressors. Coral reef organism holobionts, or the host along with its microbial components, are key to reef ecosystem success and functioning. Marine microbes...
Losses of corals worldwide emphasize the need to understand what drives reef decline. Stressors such as overfishing and nutrient pollution may reduce resilience of coral reefs by increasing coral–algal competition and reducing coral recruitment, growth and survivorship. Such effects may themselves develop via several mechanisms, including disruption of coral microbiomes....
With the continued and unprecedented decline of coral reefs worldwide, evaluating the factors that contribute to coral demise is of critical importance. As coral cover declines, macroalgae are becoming more common on tropical reefs. Interactions between these macroalgae and corals may alter the coral microbiome, which is thought to play...
Reproductive timing in corals is associated with environmental variables including temperature, lunar periodicity, and
seasonality. Although it is clear that these variables are interrelated, it remains unknown if one variable in particular acts as
the proximate signaler for gamete and or larval release. Furthermore, in an era of global warming,...
Background: Corals are capable of launching diverse immune defenses at the site of direct contact with pathogens, but the molecular mechanisms of this activity and the colony-wide effects of such stressors remain poorly understood. Here we compared gene expression profiles in eight healthy Acropora hyacinthus colonies against eight colonies exhibiting...
This study compares percent cover of benthic organisms at the species level at Pearl and Hermes
Atoll (PHA), the largest atoll in the Northwestern Hawaiian Islands, in order to determine 1) the
degree of difference among sites, 2) whether wave exposure zones explain observed patterns in
benthic community structure, and...
Biological invasions have been identified as one of the prominent drivers of global environmental change. In particular, invasive predators typically have substantial negative effects on populations of native prey, even driving species to extinction in extreme cases. However, beyond direct predatory effects, little is understood regarding the specific mechanisms by...
On coral reefs, disturbances rarely occur in isolation. Global stressors such as increasing seawater temperature often coincide with local stressors like nutrient pollution. In the face of increasing anthropogenic stress, corals can function as environmental sentinels, although little is known about how multiple stressors interact to disrupt their associated bacterial...
Coral reef ecosystems provide many important services to society. Their importance is not only proved by their beauty but also because they provide food and livelihood for millions of people in communities around the world, especially in developing countries. This paper estimates the economic value of coral ecosystems and potential...
The Pacific red lionfish has recently invaded Western Atlantic and Caribbean coral reefs, and may become one of the most ecologically harmful marine fish introductions to date. Lionfish possess a broad suite of traits that makes them particularly successful invaders and strong negative interactors with native fauna, including defensive venomous...
Tropical coral reef ecosystems are very important from both the ecological and economical
points of view. However, they are also particularly fragile, and have been
declining in recent years in most regions of the world, since they are highly susceptible
to anthropogenic stressors operating at global scales (e.g., global warming...
Coral reef ecosystems continue to be significantly altered by disease epizootics, but why some host populations remain resistant while others succumb to outbreaks remains unknown. Research across diverse animal and plant host systems has revealed that disease severity is strongly influenced by host genetics and by environmental influences on both...
Since the preindustrial era, the average surface ocean pH has declined by 0.1 pH units and is predicted to decline by an additional 0.3 units by the year 2100. Although subtle, this decreasing pH has profound effects on the seawater saturation state of carbonate minerals and is thus predicted to...
Coral reefs are diverse ecosystems and serve many purposes including preventing erosion on coastlines and acting as a source of food, income, and culture. Acropora cervicornis, a staghorn coral, has faced a significant 80-89% decline in the Caribbean, attributed to a poorly-characterized epizootic, White Band Disease (WBD). Previous studies showed...
Nutrients play a large role in sustaining the symbiotic relationship between the algae and host sea anemone. The endosymbiotic algae provides the host with fixed nitrogen, sugars, and inorganic food sources, while the host provides the algae with shelter and nitrogenous waste. If the anemone does not receive the proper...
Coral reefs have become vulnerable to climate change, with mass bleaching events, the loss of symbiotic algae (Symbiodiniaceae), increasing in both frequency and severity. As climate change continues to threaten the persistence and existence of coral reefs around the world, the biggest question posed for coral reefs is “can they...
Corals form the foundation for coral reef ecosystems and contain symbiotic dinoflagellates which greatly contribute to reef primary productivity. Loss of dinoflagellates from animal (host) cells results in cnidarian bleaching which leads to decreased coral fitness, and reef deterioration. Elevated temperature, caused by global warming, is the primary environmental stressor...
The symbiotic relationship between cnidarians and algae is important to the marine ecosystem due to the photosynthesis produced by the algae and the coral reefs that cnidarians provide. Corals provide their algal partner with a safe home and the algae supply the cnidarians with inorganic materials as a food source....
The modern world has presented many threats to the health and stability of ecosystems worldwide. One of the most biodiverse ecosystems, coral reefs, faces particularly strong pressures, and is already declining rapidly in complexity and area. Although the stressors that affect reefs are diverse, ranging from nutrient pollution to overfishing,...
Predatory lionfishes (Pterois volitans and P. miles) were introduced to Florida waters during the mid to late 1980s, and eventually established self-sustaining breeding populations in the tropical western Atlantic. These invasive species are now widespread along the southeastern seaboard of the United States, across the Caribbean Sea, and in the...
Full Text:
the Invasive Pacific Red Lionfish Pterois volitans on Native Atlantic
Coral-reef Fish Communities
Mutualistic associations between corals and symbiotic microalgae of the genus Symbiodium power tropical reef ecosystems, hotspots of marine biodiversity that buffer coastlines, support tourism- and fisheries-based economies, and offer untapped potential for discovery of novel pharmaceutical compounds. However, reef ecosystems are declining at an alarming rate, in large part due...
Biodiversity loss in highly diverse systems such as coral reefs has been linked to significant declines in the ecosystem functions and services provided by marine species. Ecological functioning of coral reefs and the resistance of coral reef fish communities to disturbance depend on the functional traits of species that promotes...
Caribbean coral reefs have deteriorated substantially over the past 30 years, which
is broadly attributable to the effects of global climate change. In the same time,
Indo-Pacific reefs maintain higher coral cover and typically recover rapidly after
disturbances. This difference in reef resilience is largely due to much higher
coral...
Full Text:
acidification
causes bleaching and productivity loss in coral reef builders. Proceedings of the National
Academy
Coral reefs, found in tropical regions, are renowned for their rich biodiversity and their contributions to ecological, cultural, and economic aspects worldwide. The success of coral reefs hinges on the symbiotic partnership between corals and their dinoflagellate algae, from the family Symbiodiniaceae. The algae reside within the coral host’s gastrodermal...
The Mesoamerican Barrier Reef System has considerably changed after a series of natural disturbances, especially hurricanes and extreme coral bleaching, and is further impacted by anthropogenic threats. Located at a tri-national border between Belize, Guatemala and Honduras, the Sapodilla Cayes Range is specifically impacted by tourism, commercial fishing and other...
Coral reproduction is vital to the persistence of coral reefs. Decades of ecological studies have correlated environmental variables, such as temperature and light, to the timing of reproduction in anthozoan cnidarians, including corals and sea anemones. However, elevated temperatures associated with climate change impair reproductive success and threaten the resilience...
Symbiotic relationships between cnidarians and dinoflagellates within the genus
Symbiodinium are critically important for the success of coral reefs. These symbionts
provide their hosts with photosynthetically-fixed carbon in exchange for nutrients
and shelter. Symbiodinium is a phylogenetically diverse genus that is often typed by
sequencing the ribosomal internal transcribed spacer...
Full Text:
(naFve)
Aiptasia
sp.
Florida
B1
2
Hard
Coral
Florida
B1
3
So
Symbiotic relationships between cnidarians and dinoflagellates within the genus
Symbiodinium are critically important for the success of coral reefs. These symbionts
provide their hosts with photosynthetically-fixed carbon in exchange for nutrients
and shelter. Symbiodinium is a phylogenetically diverse genus that is often typed by
sequencing the ribosomal internal transcribed spacer...
Full Text:
tropical reefs
Coral reefs provide a habitat for a disproportionate number of species in comparison to
The symbiosis between cnidarians (e.g., corals or sea anemones) and intracellular dinoflagellate algae of the genus Symbiodinium is of immense ecological importance. In particular, this symbiosis promotes the growth and survival of reef corals in nutrient-poor tropical waters; indeed, coral reefs could not exist without this symbiosis. However, our fundamental...
Biogeochemical mechanisms employed by key organisms, or symbiotic associations of organisms, transform the function and structure of their environment through processes recognized as ecosystem engineering. This dissertation seeks to investigate organism-ecosystem interactions that serve globally significant ecological functions in marine systems and impact how systems respond to environmental change. Using...