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Title: The Role Of Disturbance In The Genotypic And Morphological Diversity Of Halodule Wrightii.
Creator: Tiling, Kathryn A., Proffitt, C. Edward, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Seagrasses are important foundation species in coastal ecosystems. Genetic diversity of seagrasses can influence a number of ecological factors including, but not limited to, disturbance resistance and resilience. Seagrasses in the Indian River Lagoon (IRL), Florida are considered to be highly disturbed due to frequent events, like algal blooms, that impair water quality, reducing available light for seagrass growth. Halodule wrightii is a dominant seagrass throughout the IRL, but its genetic...
Show moreSeagrasses are important foundation species in coastal ecosystems. Genetic diversity of seagrasses can influence a number of ecological factors including, but not limited to, disturbance resistance and resilience. Seagrasses in the Indian River Lagoon (IRL), Florida are considered to be highly disturbed due to frequent events, like algal blooms, that impair water quality, reducing available light for seagrass growth. Halodule wrightii is a dominant seagrass throughout the IRL, but its genetic diversity has only been quantified in a few Gulf of Mexico and Florida Bay populations and little is known about its potential ecological consequences. I quantified the genetic variation of H. wrightii using microsatellite markers in the southern IRL to determine: (i) how disturbance history influenced genetic diversity, (ii) if morphology of clones was, in part, genetically controlled and related to disturbance history, and (iii) if genotypes showed phenotypic plasticity in response to disturbances. In the IRL, H. wrightii populations exhibited moderate genetic diversity that varied with disturbance history. The disturbance history of a population was classified by the variance in the percent occurrence of H. wrightii over a 16-year period. Genotypic richness and clonal diversity of H. wrightii increased with increasing disturbance histories. Other genetic diversity measures (e.g., allelic richness, observed heterozygosity) did not change with disturbance history. These findings suggest that impacts to seagrass coverage over time can change the genotypic composition of populations. When different genotypes of H. wrightii were grown in a common garden, differences in leaf characteristics among genotypes provided evidence that morphological trait variation is, in part, explained by genetic variance. The disturbance history of genotypes did not directly affect morphological traits. However, significant genotype x site (within disturbance history) interactions found greater variation in shoot density and below ground traits of H. wrightii genotypes from sites of intermediate disturbance history. Traits of H. wrightii were shown to be phenotypically plastic. Significant genotype x environment interactions for shoot density and height demonstrated that genotypes responded differently by increasing, decreasing, and not changing sizes in response to light reduction. Genetic diversity of H. wrightii has strong implications for ecological function in coastal communities.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004661, http://purl.flvc.org/fau/fd/FA00004661
Subject Headings: Indian River (Fla. : Lagoon) -- Enviornmental conditions, Indian River Lagoon National Estuary Program (Fla.), Marine ecology -- Florida -- Indian River (Lagoon), Restoration ecology, Seagrasses -- Florida -- Indian River (Lagoon), Seagrasses -- Physiology
Format: Document (PDF)

Title: A comparison of primary production rates in Indian River, Florida seagrass systems.
Creator: Heffernan, John J., Gibson, R. A., Harbor Branch Oceanographic Institute
Date Issued: 1983
PURL: http://purl.flvc.org/fau/fd/FA00007477
Subject Headings: Indian River (Fla. : Lagoon), Primary productivity (Biology), Seagrasses--Florida--Indian River (Lagoon)
Format: Document (PDF)

Title: Seagrass beds versus sand bottoms: the trophic importance of their associated benthic invertebrates.
Creator: Virnstein, Robert W., Mikkelsen, Paul S., Cairns, Kalani D., Capone, Mary Ann, Harbor Branch Oceanographic Institute
Date Issued: 1983
PURL: http://purl.flvc.org/fau/fd/FA00007480
Subject Headings: Seagrasses--Florida--Indian River (Lagoon), Meiofauna, Aquatic invertebrates., Food chains (Ecology)
Format: Document (PDF)

Title: Perception and choice of substratum by epifaunal amphipods associated with seagrasses.
Creator: Stoner, Allan W., Harbor Branch Oceanographic Institute
Date Issued: 1980
PURL: http://purl.flvc.org/FCLA/DT/3350838
Subject Headings: Amphipoda, Seagrasses, Biomass, Lagodon rhomboids, Predation (Biology), Indian River (Fla.: Lagoon)
Format: Document (PDF)

Title: Measurements of short-term turnover of epifauna within seagrass beds using an in situ staining method.
Creator: Howard, Robert K., Harbor Branch Oceanographic Institute
Date Issued: 1985
PURL: http://purl.flvc.org/FCLA/DT/3350850
Subject Headings: Seagrasses, Benthic animals, Staining and stains (Microscopy), Crustaceans, Indian River (Fla.: Lagoon)
Format: Document (PDF)

Title: Diel variation in the abundance of epifauna associated with seagrasses of the Indian River, Florida, USA.
Creator: Howard, Robert K., Harbor Branch Oceanographic Institute
Date Issued: 1987
PURL: http://purl.flvc.org/FCLA/DT/3333098
Subject Headings: Seagrasses--Florida--Indian River (Lagoon), Diel cycles, Benthic animals, Circadian rhythms
Format: Document (PDF)

Title: Leaf growth rate of the seagrass Halodule Wrightii photographically measured in situ.
Creator: Virnstein, Robert W., Harbor Branch Oceanographic Institute
Date Issued: 1982
PURL: http://purl.flvc.org/FCLA/DT/3331831
Subject Headings: Seagrasses--Florida--Indian River (Lagoon), Leaves--Growth, Photographic measurements, Photogrammetry
Format: Document (PDF)

Title: Effects of a decomposing drift algal mat on sediment pore water nutrient concentrations in a Florida seagrass bed.
Creator: Zimmermann, Carl F., Montgomery, John R., Harbor Branch Oceanographic Institute
Date Issued: 1984
PURL: http://purl.flvc.org/FCLA/DT/3350848
Subject Headings: Seagrasses, Pore water --Florida --Indian River, Algae --Ecology, Sediment control, Ammonium, Phosphate deposits
Format: Document (PDF)

Title: Production and nutrient dynamics of a Syringodium filiforme Kütz. seagrass bed in Indian River Lagoon, Florida.
Creator: Short, F. T., Montgomery, John R., Zimmermann, Carl F., Short, C. A., Harbor Branch Oceanographic Institute
Date Issued: 1993
PURL: http://purl.flvc.org/FCLA/DT/3174032
Subject Headings: Seagrasses, Plant nutrients, Aquatic ecology, Sediment transport, Ammonium --Environmental aspects --Measurement
Format: Document (PDF)

Title: Blade abandonment/proliferation: a novel mechanism for rapid epiphyte control in marine macrophytes.
Creator: Littler, Mark M., Littler, Diane S., Harbor Branch Oceanographic Institute
Date Issued: 1999
PURL: http://purl.flvc.org/FCLA/DT/3172820
Subject Headings: Marine algae culture, Plant-water relationships, Plant ecology, Coral reef ecology, Seagrasses --Habitat
Format: Document (PDF)

Title: A 13C/12C comparison of food webs in Caribbean seagrass meadows and coral reefs.
Creator: Fry, B., Lutes, R., Northam, M., Parker, P. L., Harbor Branch Oceanographic Institute
Date Issued: 1982
PURL: http://purl.flvc.org/FCLA/DT/3331838
Subject Headings: Carbon--Isotopes--Analysis, Seagrasses, Coral reefs and islands--Caribbean Area, Food webs
Format: Document (PDF)

Title: Subtropical-tropical seagrass communities of the Southeastern United States: fishes and fishcommunities.
Creator: Gilmore, R. G., Harbor Branch Oceanographic Institute
Date Issued: 1987
PURL: http://purl.flvc.org/fau/fd/FA00007291
Subject Headings: Southeastern United States, Fish communities, Fishes, Seagrasses--Ecology, Fishes--Habitat
Format: Document (PDF)

Title: The seagrass filter: purification of estuarine and coastal waters.
Creator: Short, F. T., Short, C. A., Harbor Branch Oceanographic Institute
Date Issued: 1984
PURL: http://purl.flvc.org/FCLA/DT/3353740
Subject Headings: Seagrasses, Estuaries, Water--Purification--Filtration, Coastal waters, Filters and filtration
Format: Document (PDF)

Title: An illustrated guide to the sea grasses of the Indian River region of Florida.
Creator: Eiseman, N. J.
Date Issued: 1980
PURL: http://purl.flvc.org/fcla/dt/3358738
Subject Headings: Seagrasses--Florida--Indian River (Lagoon), Halophila, Species, Cymodoceaceae, Illustrated guides
Format: Document (PDF)

Title: Community studies in seagrass meadows: A comparison of two methods for sampling macroinvertebrates and fishes.
Creator: Leber, Kenneth M., Greening, Holly S., Harbor Branch Oceanographic Institute
Date Issued: 1986
PURL: http://purl.flvc.org/FCLA/DT/3336787
Subject Headings: Seagrasses--Ecology, Sampling--Technique, Invertebrates, Fishes, Scrapers (Tools), Trawls and trawling
Format: Document (PDF)

Title: Biomonitoring of hypoxia and sulfide stress in three sub-tropical seagrasses.
Creator: Irwin, Connor., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Hypoxia and sulfide exposure, increased using glucose, are considered major environmental stressors in seagrass communities. Quantum efficiency, total soluble protein and catalase activity were quantified to evaluate the applicability of each of these bioindicators to detect environmental stress in three tropical seagrass species, Thalassia testudinum (Banks ex Kèoenig), Halodule wrightii (Ascherson) and Syringodium filiforme (Kuetz). Hypoxia + sulfide treatments significantly decreased the...
Show moreHypoxia and sulfide exposure, increased using glucose, are considered major environmental stressors in seagrass communities. Quantum efficiency, total soluble protein and catalase activity were quantified to evaluate the applicability of each of these bioindicators to detect environmental stress in three tropical seagrass species, Thalassia testudinum (Banks ex Kèoenig), Halodule wrightii (Ascherson) and Syringodium filiforme (Kuetz). Hypoxia + sulfide treatments significantly decreased the quantum efficiency of all three species, but showed no response in protein and catalase activity. Although no treatment effect was found, catalase activity was enhanced in T. testudinum leaves and H. wrightii roots relative to other tissues, while S. filiforme showed no location-specific catalase activity. These results indicate that quantum efficiency is a more sensitive indicator than protein and catalase activity to hypoxia and sulfide stress in seagrasses.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2976445
Subject Headings: Plant physiology, Environmental management, Seagrasses, Habitat, Environmental aspects, Sulfites, Physiological effect, Marine ecology
Format: Document (PDF)

Title: Epiphyte productivity and community structure in conjunction with HPLC pigment analysis.
Creator: Singh, Alya G., Florida Atlantic University, Louda, J. William
Abstract/Description: Seagrass meadows in Florida Bay have rapidly declined due to synergistic stresses. The microalgal communities present on the leaves of Thalssia testudinum were studied in the Snake Bight and Whipray Basin areas of Florida Bay. These areas have been the sites of recurrent phytoplankton blooms and this study was aimed at exploring similar effects within the microalgal epiphytic communities. Epiphytometers, or surrogate seagrass, were used to provide a time zero (T0) point which is impossible in...
Show moreSeagrass meadows in Florida Bay have rapidly declined due to synergistic stresses. The microalgal communities present on the leaves of Thalssia testudinum were studied in the Snake Bight and Whipray Basin areas of Florida Bay. These areas have been the sites of recurrent phytoplankton blooms and this study was aimed at exploring similar effects within the microalgal epiphytic communities. Epiphytometers, or surrogate seagrass, were used to provide a time zero (T0) point which is impossible in natural samples. Epiphyte samples were analyzed using HPLC/PDA which provided measurements of standing crop and community structure (>90% diatom). Epiphytometers were found to be excellent tool for monitoring epiphyte productivity on Thalassia. The monitoring of productivity, standing crop and community structure should allow insight into positive and negative effects of water supply changes.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/13066
Subject Headings: Epiphytes, High performance liquid chromatography, Seagrasses--Florida--Florida Bay, Thalassia--Florida--Florida Bay
Format: Document (PDF)

Title: Sulfur-35 incorporation in the seagrass Thalassia testudinum under oxic and anoxic conditions.
Creator: Peters, Jasmine Star., Florida Atlantic University, Koch, Marguerite
Abstract/Description: Currently, there is a great deal of interest in the role of sulfur in the seagrass ecosystems and for sulfide, a known phytotoxin, in particular. This research used a 35S tracer technique to examine sulfur metabolism in the seagrass Thalassia testudinum. The uptake of the 35S radiotracer was documented at similar rates under both oxic and anoxic treatments. The highest total radioactivity was in root and rhizome tissue, as compared to the leaves. 35S translocation from roots to leaves was...
Show moreCurrently, there is a great deal of interest in the role of sulfur in the seagrass ecosystems and for sulfide, a known phytotoxin, in particular. This research used a 35S tracer technique to examine sulfur metabolism in the seagrass Thalassia testudinum. The uptake of the 35S radiotracer was documented at similar rates under both oxic and anoxic treatments. The highest total radioactivity was in root and rhizome tissue, as compared to the leaves. 35S translocation from roots to leaves was found to be more efficient in young versus mature leaves. Total sulfur uptake was estimated and found to be significantly different between root and rhizome tissue under oxic conditions. In the anoxic treatment, 1 mM sulfide may have been a threshold, at which the seagrass showed reduced uptake of 35S into the below-ground tissue. While the plants assisted in the production of sulfide in this experiment, sulfide accumulation may inhibit 35S uptake. This is counter to the idea of increased sulfide intrusion under sediment hypoxia. This study represents the first attempt to use 35S to trace sulfur incorporation into seagrass; further research will be required to understand the complex sulfur biochemistry of these important marine plants using this method.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13385
Subject Headings: Seagrasses--Ecology, Sulfates--Physiological effect, Plant morphology, Marine sediments
Format: Document (PDF)

Title: INTERNAL OXYGEN DYNAMICS AND RHIZOSPHERE OXIDATION IN TROPICAL SEAGRASS, THALASSIA TESTUDINUM.
Creator: Winn, Nathaniel, Koch-Rose, Marguerite, Florida Atlantic University, Department of Environmental Sciences, Charles E. Schmidt College of Science
Abstract/Description: Large-scale seagrass mortality events have been linked to internal hypoxia and exposure to phytotoxins in the sediment, such as hydrogen sulfide (H2S). Although seagrasses can transport oxygen (O2) to belowground tissues (rhizomes and roots) and into surrounding sediment to prevent H2S intrusion, reoccurring seagrass mortality events from H2S exposure continue. In the present study, I examined the potential of tropical seagrass Thalassia testudinum to transport O2 effectively to belowground...
Show moreLarge-scale seagrass mortality events have been linked to internal hypoxia and exposure to phytotoxins in the sediment, such as hydrogen sulfide (H2S). Although seagrasses can transport oxygen (O2) to belowground tissues (rhizomes and roots) and into surrounding sediment to prevent H2S intrusion, reoccurring seagrass mortality events from H2S exposure continue. In the present study, I examined the potential of tropical seagrass Thalassia testudinum to transport O2 effectively to belowground tissues and diffuse O2 into Florida Bay sediment around the root rhizosphere or sediment-root interface to constrain H2S diffusion into the roots. My approach was to (1) examine the spatial distribution of O2 in the rhizosphere during the light and dark with 2-D planar optode sensors, (2) examine patterns of root O2 loss (ROL) with O2 dye tracing experiments, and (3) measure O2 and H2S dynamics in internal tissues and rhizospheres. My results indicate that T. testudinum effectively sustains oxidation in belowground tissues to constrain H2S, but minimal evidence of ROL into the rhizosphere.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014365
Subject Headings: Turtle grass Seagrasses, Thalassia testudinum, Hydrogen sulfide--Environmental aspects, Rhizosphere
Format: Document (PDF)

Title: Experimental studies of decapod and fish predation on seagrass macrobenthos.
Creator: Nelson, Walter G., Harbor Branch Oceanographic Institute
Date Issued: 1981
PURL: http://purl.flvc.org/FCLA/DT/3350839
Subject Headings: Decapoda (Crustacea), Predation (Biology), Lagodon rhomboids, Blue crab, Palaemonetes, Penaeus duorarum, Seagrasses --Ecology, Indian River (Fla.: Lagoon)
Format: Document (PDF)

HBOI Faculty Contributions (65)	+ -
FAU Theses and Dissertations (13)	+ -
HBOI Technical Reports (5)	+ -
Honors Student Theses (1)	+ -

Seagrasses (44)	+ -
Seagrasses--Florida--Indian River (Lagoon) (14)	+ -
Seagrasses--Ecology (13)	+ -
Indian River (Fla. : Lagoon) (8)	+ -
Predation (Biology) (8)	+ -

Biomass (7)	+ -
Algae (6)	+ -
Seagrasses --Habitat (6)	+ -
Benthic animals (5)	+ -
Epiphytes (5)	+ -
Seagrasses--Habitat (5)	+ -
Amphipoda (4)	+ -
Decapoda (Crustacea) (4)	+ -
Estuaries (4)	+ -
Fishes (4)	+ -
Indian River (Fla.: Lagoon) (4)	+ -
Seagrasses --Ecology (4)	+ -
Seagrasses--Florida (4)	+ -
Species (4)	+ -
Thalassia (4)	+ -
Aquatic plants (3)	+ -
Crustaceans (3)	+ -
Halophila (3)	+ -
Seagrass restoration (3)	+ -
Thalassia testudinum (3)	+ -
Turtle grass (3)	+ -
Eutrophication (2)	+ -
Food webs (2)	+ -
Gastropoda (2)	+ -
Grazing (2)	+ -

article (65)	+ -
Electronic Thesis or Dissertation (13)	+ -
technical report (5)	+ -
thesis (1)	+ -

Harbor Branch Oceanographic Institute (57)	+ -
Virnstein, Robert W. (13)	+ -
Florida Atlantic University (12)	+ -
Stoner, Allan W. (10)	+ -
Howard, Robert K. (7)	+ -

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