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Characterization of symbiotic algae, genus Symbiodinium, in corals at St. Lucie reef, Florida
Title
Characterization of symbiotic algae, genus Symbiodinium, in corals at St. Lucie reef, Florida.
Creator
Klepac, Courtney, Voss, Joshua, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
The unique coral reef at St. Lucie Reef (Stuart, FL) persists despite environmental variability from extensive freshwater discharges, summer upwelling, and thermal instability. By examining the symbiotic zooxanthellae, or Symbiodinium, that reside in corals, we can gain insight to coral physiology impacted by local stressors. Two scleractinian corals, Montastraea cavernosa and Pseudodiploria clivosa were sampled over 1.5 years, including both wet and dry seasons. Zooxanthellae were isolated...
Show moreThe unique coral reef at St. Lucie Reef (Stuart, FL) persists despite environmental variability from extensive freshwater discharges, summer upwelling, and thermal instability. By examining the symbiotic zooxanthellae, or Symbiodinium, that reside in corals, we can gain insight to coral physiology impacted by local stressors. Two scleractinian corals, Montastraea cavernosa and Pseudodiploria clivosa were sampled over 1.5 years, including both wet and dry seasons. Zooxanthellae were isolated and quantitatively characterized using standard measurements and molecular techniques. Both coral species varied in zooxanthellae biomass, where Pseudodiploria clivosa had Higher cell densities and chlorophyll concentrations than Montastraea cavernosa. Over time, these parameters varied, but were not significantly altered by fresh water discharge events. Symbiodinium diversity and abundance were identified by ITS2 region amplification and next-generation sequencing .Novel associations between Symbiodinium and each coral explained the observed physiological differences. The symbioses remained stable throughout and could indicate local adaptation for St. Lucie Reef corals.
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Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004211
Subject Headings
Adaptation (Biology), Coral reef biology, Coral reef ecology, Marine chemical ecology, St. Lucie Reef (Stuart, Fla.) -- Environmental aspects, St. Lucie River Estuary (Fla.) -- Environmental aspects
Format
Document (PDF)
Coral-Algal Symbioses in Mesophotic Montastraea cavernosa in the Gulf of Mexico
Title
Coral-Algal Symbioses in Mesophotic Montastraea cavernosa in the Gulf of Mexico.
Creator
Polinski, Jennifer, Voss, Joshua, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Mesophotic reefs represent biodiverse ecosystems that may act as a refuge for depth-generalist coral species threatened in shallow habitats. Despite the importance of coral-algal symbioses, few studies focus on mesophotic zooxanthellae assemblages and their influence on connectivity. This study compared zooxanthellae in Montastraea cavernosa at shallow and mesophotic depths at Flower Garden Banks National Marine Sanctuary and McGrail Bank. Mesophotic corals contained more zooxanthellae and...
Show moreMesophotic reefs represent biodiverse ecosystems that may act as a refuge for depth-generalist coral species threatened in shallow habitats. Despite the importance of coral-algal symbioses, few studies focus on mesophotic zooxanthellae assemblages and their influence on connectivity. This study compared zooxanthellae in Montastraea cavernosa at shallow and mesophotic depths at Flower Garden Banks National Marine Sanctuary and McGrail Bank. Mesophotic corals contained more zooxanthellae and more chlorophyll a and c2 per unit area coral. Increased zooxanthellae within mesophotic corals may represent an adaptive strategy to optimize light capture in low-light environments. Genetic profiles for zooxanthellae assemblages from shallow and mesophotic corals showed similar diversity across banks and between depths. The dominant sequence making up assemblages was identified as Symbiodinium type C1. Similar assemblage diversity suggests that zooxanthellae assemblages will not limit connectivity potential between shallow and mesophotic corals at these reefs.
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Date Issued
2016
PURL
http://purl.flvc.org/fau/fd/FA00004665, http://purl.flvc.org/fau/fd/FA00004665
Subject Headings
Adaptation (Biology), Coral reef biology, Coral reef ecology -- Research, Coral reefs and islands -- Monitoring, Corals -- Habitat, Marine biodiversity, Marine resources conservation
Format
Document (PDF)
Effects of St. Lucie Estuarine Discharge Water and Thermal Stress on the Coral Montastraea cavernosa
Title
Effects of St. Lucie Estuarine Discharge Water and Thermal Stress on the Coral Montastraea cavernosa.
Creator
Shatters, Alycia, Voss, Joshua, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Coral reef declines, particularly in coastal zones, have been linked to thermal stress and anthropogenic impacts on water quality. St. Lucie Reef near Stuart, Florida receives increased estuarine efflux as a result of watershed changes and management policies that have substantially altered historic, natural flows. This research used ambient and elevated temperatures (25°C and 30°C, respectively), and offshore versus St. Lucie Estuarine discharge water to investigate the individual and...
Show moreCoral reef declines, particularly in coastal zones, have been linked to thermal stress and anthropogenic impacts on water quality. St. Lucie Reef near Stuart, Florida receives increased estuarine efflux as a result of watershed changes and management policies that have substantially altered historic, natural flows. This research used ambient and elevated temperatures (25°C and 30°C, respectively), and offshore versus St. Lucie Estuarine discharge water to investigate the individual and interactive effects of thermal and water quality stress on Montastraea cavernosa, a dominant scleractinian coral species at St. Lucie Reef. These goals were accomplished using ex-situ, factorial, experimental design that was supplemented with existing in-situ monitoring on St. Lucie Reef. Zooxanthellae density and chlorophyll content were evaluated to determine effects on the corals and their symbionts. Zooxanthellae populations were significantly affected by thermal stress. Significant interactions between temperature and water treatment were observed, suggesting that the impacts of discharge water may be supplanted when corals are exposed to thermal stress. In a supplement to the experiment, M. cavernosa colonies transplanted from Palm Beach to St. Lucie Reef demonstrated resilience despite exposure to more variable environmental conditions. Collaborative partnerships with multiple state agencies and local government offices facilitated data sharing to inform decision making for South Florida’s resource management strategies. Creating effective resource management is crucial for the conservation of coastal ecosystems impacted by land-based sources of pollution both locally and globally.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004843, http://purl.flvc.org/fau/fd/FA00004843
Subject Headings
Coral declines., Coral reef management., Estuarine pollution., Water--Pollution.
Format
Document (PDF)
Genetic Connectivity and Phenotypic Plasticity of Shallow and Mesophotic Coral Ecosystems in the Gulf of Mexico
Title
Genetic Connectivity and Phenotypic Plasticity of Shallow and Mesophotic Coral Ecosystems in the Gulf of Mexico.
Creator
Studivan, Michael, Voss, Joshua, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Coral reef ecosystems worldwide are facing increasing degradation due to disease, anthropogenic damage, and climate change, particularly in the Tropical Western Atlantic. Mesophotic coral ecosystems (MCEs) have been recently gaining attention through increased characterization as continuations of shallow reefs below traditional SCUBA depths (>30 m). As MCEs appear to be sheltered from many stressors affecting shallow reefs, MCEs may act as a coral refuge and provide larvae to nearby shallow...
Show moreCoral reef ecosystems worldwide are facing increasing degradation due to disease, anthropogenic damage, and climate change, particularly in the Tropical Western Atlantic. Mesophotic coral ecosystems (MCEs) have been recently gaining attention through increased characterization as continuations of shallow reefs below traditional SCUBA depths (>30 m). As MCEs appear to be sheltered from many stressors affecting shallow reefs, MCEs may act as a coral refuge and provide larvae to nearby shallow reefs. The Deep Reef Refugia Hypothesis (DRRH) posits that shallow and mesophotic reefs may be genetically connected and that some coral species are equally compatible in both habitats. The research presented here addresses key questions that underlie this theory and advances our knowledge of coral connectivity and MCE ecology using the depth-generalist coral Montastraea cavernosa. Chapter 1 presents an overview of the DRRH, a description of MCEs in the Gulf of Mexico (GOM), and the framework of research questions within existing reef management infrastructure in the GOM. Through microsatellite genotyping, Chapter 2 identifies high connectivity among shallow and mesophotic reefs in the northwest GOM and evidence for relative isolation between depth zones in Belize and the southeast GOM. Historical migration and vertical connectivity models estimate Gulf-wide population panmixia. Chapter 3 focuses on population structure within the northwest GOM, identifying a lack of significant population structure. Dominant migration patterns estimate population panmixia, suggesting mesophotic populations currently considered for National Marine Sanctuary protection benefit the Flower Garden Banks. Chapter 4 quantifies the level of morphological variation between shallow and mesophotic M. cavernosa, revealing two distinct morphotypes possibly representing adaptive tradeoffs. Chapter 5 examines the transcriptomic mechanisms behind coral plasticity between depth zones, discovering a consistent response to mesophotic conditions across regions. Additionally, variable plasticity of mesophotic corals resulting from transplantation to shallow depths and potential differences in bleaching resilience between shallow and mesophotic corals are identified. The dissertation concludes with a synthesis of the results as they pertain to connectivity of shallow and mesophotic corals in the Gulf of Mexico and suggests future research that will aid in further understanding of MCE ecology and connectivity.
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Date Issued
2018
PURL
http://purl.flvc.org/fau/fd/FA00005961
Subject Headings
Coral reef ecology--Mexico, Gulf of, Phenotypic plasticity, Montastraea, Ecological genetics
Format
Document (PDF)
HYPOSALINITY STRESS TOLERANCES OF THE CORALS MONTASTRAEA CAVERNOSA AND PORITES ASTREOIDES IN SOUTHEAST FLORIDA AND IMPLICATIONS FOR COASTAL FRESHWATER MANAGEMENT
Title
HYPOSALINITY STRESS TOLERANCES OF THE CORALS MONTASTRAEA CAVERNOSA AND PORITES ASTREOIDES IN SOUTHEAST FLORIDA AND IMPLICATIONS FOR COASTAL FRESHWATER MANAGEMENT.
Creator
Davis, Haley A., Voss, Joshua, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
Abstract/Description
Coastal development shifts natural hydrology through water redirection, increased impervious surfaces, and increased connectivity to the coastal ocean through inlets. In Southeast Florida, watershed alterations can cause flash-freshening in nearshore coastal habitats, threatening coral reef ecosystems. This study assessed the hyposalinity tolerance threshold of two prominent scleractinian corals in Southeast Florida. In a series of experiments, we determined that Montastraea cavernosa corals...
Show moreCoastal development shifts natural hydrology through water redirection, increased impervious surfaces, and increased connectivity to the coastal ocean through inlets. In Southeast Florida, watershed alterations can cause flash-freshening in nearshore coastal habitats, threatening coral reef ecosystems. This study assessed the hyposalinity tolerance threshold of two prominent scleractinian corals in Southeast Florida. In a series of experiments, we determined that Montastraea cavernosa corals have an LC50 of 19 PSU but can survive for at least 21 days at an intermediately stressful salinity of 25 PSU. Porites astreoides corals demonstrated an LC50 of 19 PSU, but experienced mortality when exposed to 25 PSU for 17–18 days. Prior to mortality, corals displayed decreased polyp activity, altered coloration, and decreased tissue integrity. These data suggest that lower-volume, longer-duration releases of freshwater from reservoirs may preserve coral health in Southeast Florida.
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Date Issued
2023
PURL
http://purl.flvc.org/fau/fd/FA00014207
Subject Headings
Montastraea, Porites, Coral reef ecology--Florida, Hydrology
Format
Document (PDF)
Population Structure and Gene Expression of the Coral Montastraea cavernosa in the Northern Florida Reef Tract
Title
Population Structure and Gene Expression of the Coral Montastraea cavernosa in the Northern Florida Reef Tract.
Creator
Dodge, Danielle, Voss, Joshua, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Coral reefs on Florida’s Reef Tract (FRT) are susceptible to many anthropogenic influences including controlled freshwater discharges and agricultural runoff as well as high natural environmental variability from seasonal rainfall, runoff and upwelling. To better understand coral population structure and responses to sublethal stressors, populations of the scleractinian coral Montastraea cavernosa in the northern FRT were examined using a combination of genomic and transcriptomic techniques....
Show moreCoral reefs on Florida’s Reef Tract (FRT) are susceptible to many anthropogenic influences including controlled freshwater discharges and agricultural runoff as well as high natural environmental variability from seasonal rainfall, runoff and upwelling. To better understand coral population structure and responses to sublethal stressors, populations of the scleractinian coral Montastraea cavernosa in the northern FRT were examined using a combination of genomic and transcriptomic techniques. Microsatellite genetic markers identified high local retention among sites and a slight southward gene flow. An in-situ temporal gene expression analysis utilizing a tag-based sequencing transcriptomic approach was used to analyze baseline coral health at St. Lucie Reef (SLR), off Stuart, FL. Temporal variation had the greatest influence of differential gene expression among M. cavernosa at SLR. Results will be shared with local resource managers and coupled with a complementary ex-situ experimental trial.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00005920
Subject Headings
Dissertations, Academic -- Florida Atlantic University, Montastraea, Coral reef ecology--Florida., Corals--Effect of stress on, Gene expression--Analysis.
Format
Document (PDF)