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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Changes in coral community structure in Barbados : effects of eutrophication and reduced grazing pressure

Allard, Patrick January 1993 (has links)
No description available.
62

The impacts of harmful algal blooms on a Florida reef fish community

Unknown Date (has links)
Coral reefs worldwide are threatened by many environmental disturbances including harmful algal blooms (HABs) which have been increasing on Florida coasts over the past decade. Research has mainly focused on HAB identification, percent cover and other effects on the benthos but the relationship of HABs with upper trophic levels has received less attention. To study this relationship, a two-year investigation on a 10-m deep reef off of Hallandale Beach, was conducted. Stationary fish census coupled with benthic transect videos were conducted quarterly between April 2005-July 2007. A significant correlation between Lyngbya sp. blooms and alterations in fish assemblages was observed. Lyngbya had a negative interaction with fish species and abundance; additionally, HAB sample periods were significantly different from low algal abundance periods. Blooms of Dictyota sp. had no measurable relationship with the fish assemblage indicating HABs may have variable impacts on fishes depending on family, species and chemistry of the algae. / by Rex E. Baumberger, Jr. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.
63

The importance of detritus and microenvironment nutrient enrichment to the growth of coral reef macroalgae, Halimeda and Dictyota /

Mason, Benjamin M. January 2004 (has links)
Thesis (M.S.)--University of North Carolina at Wilmington, 2004. / Includes bibliographical references (leaves : [35]-41).
64

Eco-physiological performances and reproductive biology of the soft coral Lobophytum sarcophytoides in Hong Kong.

January 2010 (has links)
Yeung, Chung Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 143-156). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract (English) --- p.iii / Abstract (Chinese) --- p.vi / Contents --- p.vii / List of Tables --- p.xii / List of Figures --- p.xii / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Ecological and economic importance of coral reef habitats --- p.1 / Chapter 1.2 --- D egradation of coral reefs --- p.2 / Chapter 1.2.1 --- Natural recovery --- p.3 / Chapter 1.2.2 --- Restoration of disturbed reefs --- p.3 / Chapter 1.2.2.1 --- Whole colony transplantation --- p.4 / Chapter 1.2.2.2 --- Fragment transplantation --- p.4 / Chapter 1.2.2.3 --- Coral nursery --- p.5 / Chapter 1.3 --- Studies on octocorals --- p.6 / Chapter 1.3.1 --- Functional ecology of octocorals --- p.7 / Chapter 1.3.2 --- Biodiversity of octocorals in Hong Kong --- p.9 / Chapter 1.3.3 --- Threats on octocorals in Hong Kong --- p.10 / Chapter 1.4 --- The focus and significance of the present study --- p.12 / Chapter 1.4.1 --- "Lobophytum sarcophytoides, the study organism" --- p.14 / Chapter 1.4.2 --- Objectives --- p.15 / Chapter 1.5 --- Thesis Outline --- p.16 / Chapter Chapter 2 --- Seasonal Variation and Size-dependent Eco-physiological Performances of the Soft Coral Lobophytum sarcophytoides / Chapter 2.1 --- Introduction --- p.19 / Chapter 2.1.1 --- Damage recovery --- p.20 / Chapter 2.1.2 --- Photosynthetic activity --- p.21 / Chapter 2.1.3 --- Reproductive biology --- p.22 / Chapter 2.1.4 --- Growth rate --- p.23 / Chapter 2.1.5 --- Significance and objectives --- p.23 / Chapter 2.2 --- Study Sites --- p.24 / Chapter 2.2.1 --- Lan Guo Shui (LGS) --- p.24 / Chapter 2.2.2 --- Tolo Harbour (MSL) --- p.25 / Chapter 2.3 --- Methodologies --- p.27 / Chapter 2.3.1 --- Sample collection --- p.27 / Chapter 2.3.2 --- Treatment of samples --- p.27 / Chapter 2.3.3 --- Health condition --- p.28 / Chapter 2.3.4 --- Damage recovery --- p.29 / Chapter 2.3.5 --- Growth rate --- p.29 / Chapter 2.3.6 --- Photosynthetic activity --- p.30 / Chapter 2.3.7 --- Reproductive biology --- p.30 / Chapter 2.3.8 --- Statistical Analysis --- p.31 / Chapter 2.4 --- Results --- p.32 / Chapter 2.4.1 --- Acclimation of transplanted corals --- p.32 / Chapter 2.4.2 --- Health condition --- p.33 / Chapter 2.4.3 --- Growth rate --- p.34 / Chapter 2.4.4 --- Photosynthetic activity --- p.38 / Chapter 2.4.5 --- Damage recovery --- p.39 / Chapter 2.4.6 --- Reproductive biology --- p.40 / Chapter 2.5 --- Discussion --- p.41 / Chapter 2.5.1 --- Diurnal expansion and contraction of colonies --- p.41 / Chapter 2.5.2 --- Size fluctuation of the colonies --- p.42 / Chapter 2.5.3 --- Possible factors for the high initial mortality of corals --- p.43 / Chapter 2.5.4 --- Causes of bleaching and the harmful effects --- p.44 / Chapter 2.5.5 --- Energy allocation between reproduction and growth --- p.47 / Chapter 2.5.6 --- Quick healing of cut fragments and its ecological implication --- p.48 / Chapter 2.5.7 --- Choice of suitable fragment size for nursery use --- p.49 / Chapter 2.5.8 --- Suitable season for conducting the experiment --- p.50 / Chapter 2.6 --- Summary --- p.51 / Chapter Chapter 3 --- Effects of Temperature on the Health Condition and Photosytnthetic Activity of the Soft Coral Lobophytum sarcophytoides / Chapter 3.1 --- Introduction --- p.69 / Chapter 3.2 --- Methodologies --- p.73 / Chapter 3.2.1 --- Sample collection --- p.73 / Chapter 3.2.2 --- Experimental set-up of aquaria for growing corals --- p.73 / Chapter 3.2.2.1 --- Temperature experiment I --- p.74 / Chapter 3.2.2.2 --- Temperature experiment II --- p.74 / Chapter 3.2.2.3 --- Temperature experiment III --- p.76 / Chapter 3.2.3 --- Health condition --- p.76 / Chapter 3.2.4 --- Photosynthetic activity --- p.77 / Chapter 3.2.5 --- Statistical analysis --- p.78 / Chapter 3.3 --- Results --- p.79 / Chapter 3.3.1 --- Temperature experiment I --- p.79 / Chapter 3.3.1.1 --- Health condition --- p.79 / Chapter 3.3.1.2 --- Photosynthetic activity --- p.80 / Chapter 3.3.2 --- Temperature experiment IIA --- p.81 / Chapter 3.3.2.1 --- Health condition --- p.81 / Chapter 3.3.2.2 --- Photosynthetic activity --- p.83 / Chapter 3.3.3 --- Temperature experiment IIB --- p.84 / Chapter 3.3.3.1 --- Health condition --- p.84 / Chapter 3.3.3.2 --- Photosynthetic activity --- p.85 / Chapter 3.3.4 --- Temperature experiment III --- p.85 / Chapter 3.3.4.1 --- Health condition --- p.85 / Chapter 3.3.4.2 --- Photosynthetic activity --- p.86 / Chapter 3.4 --- Discussion --- p.87 / Chapter 3.4.1 --- The effect of acclimation --- p.87 / Chapter 3.4.2 --- Temperature tolerance range of L. sarcophytoides --- p.90 / Chapter 3.4.3 --- Indicators of coral health --- p.92 / Chapter 3.4.3.1 --- Photosynthetic activity --- p.92 / Chapter 3.4.3.2 --- Colony contraction --- p.94 / Chapter 3.4.3.3 --- Bleaching --- p.95 / Chapter 3.4.3.4 --- Algal overgrowth --- p.97 / Chapter 3.4.3.5 --- Attachment of transplanted corals --- p.99 / Chapter 3.5 --- Summary --- p.100 / Chapter Chapter 4 --- Reproductive Biology of Lobophytum sarcophytoides / Chapter 4.1 --- Introduction --- p.114 / Chapter 4.2 --- Methodologies --- p.117 / Chapter 4.2.1 --- Study site --- p.117 / Chapter 4.2.2 --- Sample collection and treatments --- p.117 / Chapter 4.3 --- Results --- p.119 / Chapter 4.3.1 --- Gametogenic development: Size changes --- p.119 / Chapter 4.3.2 --- Gametogenic development: Developmental stages --- p.120 / Chapter 4.3.2.1 --- Oogenesis --- p.120 / Chapter 4.3.2.2 --- Spermatogenesis --- p.121 / Chapter 4.4 --- Discussion --- p.122 / Chapter 4.4.1 --- Unusual oogenic development pattern in L sarcophytoides --- p.122 / Chapter 4.4.2 --- Possible effect of lack of a temperature cue on gametogenic development --- p.123 / Chapter 4.4.3 --- Alternative explanation: Energy allocation --- p.126 / Chapter 4.5 --- Summary --- p.128 / Chapter Chapter 5 --- Summary and Perspectives --- p.137 / References --- p.143
65

Linking marine communities and ecosystems : invertebrates mediate nutrient availability in intertidal communities

Bracken, Matthew E. 12 May 2003 (has links)
While community ecologists have traditionally focused on local-scale processes, it has become apparent that a broader perspective, which explores the community-level ramifications of material fluxes within and between ecosystems, is necessary to effectively evaluate bottom-up influences on community structure and dynamics. In this dissertation, I employed ecosystem principles to understand these processes in rocky intertidal communities. I specifically examined the roles of sessile invertebrates in mediating the transfers and transformations of carbon and nitrogen in intertidal ecosystems. First, I quantified the links between nearshore pelagic and rocky intertidal systems. By assimilating suspended particulate organic material (seston), mussels and other sessile invertebrates serve as mediators of material exchange from pelagic to benthic ecosystems. I evaluated these trophic linkages along productivity gradients on the coasts of New Zealand and Oregon, which allowed me to address the influences of seston quality and quantity on the growth and ammonium excretion rates of mussels. My results highlight the necessity of simultaneously considering both seston quantity (total organic particulates) and quality (phytoplankton availability) in evaluating benthic-pelagic coupling. Second, I assessed the utilization of invertebrate-excreted ammonium by macroalgae in high-intertidal pools. Sessile invertebrates not only serve as mediators of material transfer into intertidal ecosystems, they also chemically transform that material, converting particulate organic nitrogen, which is unusable by macroalgae, into ammonium, which algae readily assimilate. l showed that especially in high-zone pools, which are isolated from the ocean for 80% of the time, invertebrate-excreted ammonium is an important nitrogen source for macroalgae. Ammonium accumulated in tide pools and was subsequently taken up by algae. This novel positive interaction influenced community structure: macroalgal species richness increased with the rate of invertebrate-mediated ammonium loading in pools. Finally, by experimentally manipulating macroalgae and invertebrates in laboratory mesocosms, I quantified the effect of ammonium loading on algal growth. I demonstrated that algal nitrogen assimilation rates increased with the rate of ammonium accumulation in tide pools, which resulted in enhanced growth when invertebrates were present. Together, these studies suggest that by merging community and ecosystem perspectives we can gain unique and important insights into the bottom-up processes influencing intertidal systems. / Graduation date: 2004
66

Snapping shrimp protect host anemones from predators

Unknown Date (has links)
The sea anemone Bartholomea annulata, is an ecologically important member of Caribbean coral reefs. This anemone serves as symbiotic host to crustacean associates, some of which may control parasite loads by "cleaning" reef fishes. Associates may gain protection from predation by dwelling with anemones. B. annulata was the most abundant anemone documented on three reefs, with 52% host to crustacean symbionts. Of those occupied by multi-species groups, 92% included Alpheus armatus shrimp. A. armatus is an important anemone associate providing protection to the anemone from predators such as Hermodice carunculata, in laboratory and field trials. H. carunculata can completely devour or severely damage prey anemones. Here I show that anemones hosting symbiotic alpheid shrimp are extremely less likely to sustain damage by predators than solitary anemones. The role of protector may be reciprocally provided by anemone and decapod associates. / by Amber McCammon. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
67

The chemistry of Briareum asbestinum

Unknown Date (has links)
Briareum asbestinum, a soft coral, is a rich source of diterpenoid natural products. The secondary metabolites of B. asbestinum fall into four classes : asbestinins, briarellins, briareolate esters, and briaranes. Briareolate esters have been shown to possess biological activity and were previously only reported from Tobago. Our group recently isolated briareolate esters from a specimen collected off the coast of Boca Raton, Florida. To determine whether location has an impact on the chemistry produced by the organism, a method to discern between chemotypes was sought. Several techniques including thin layer chromatography (TLC), high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and sclerite analysis were employed, with NMR being the most successful method. By utilizing both 1H and COSY NMR experiments, it is possible to differentiate between the chemotypes of B. asbestinum. Application of this method allowed analysis of chemical variability with respect to location. / by Melody D. Rondeau. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / System requirements: Adobe Reader. / Mode of access: World Wide Web.
68

Isolation of briareolate esters from Briareum asbestinum

Unknown Date (has links)
by Rian J. Meginley. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader. / The gorgonian Briareum asbestinum is widely studied because it possesses highly oxygenated novel structures, many of which exhibit useful biological activities. Recently, two new briarane diterpenoids, briareolate esters J and K, together with two known briareolate esters have been isolated from a specimen of Briareum asbestinum collected off the coast of Boca Raton, Florida. The method used was a 96-well plate real-time cell electronic sensing (RT-CES) system to discover compounds that impact human embryonic stem cell growth. The compounds were isolated using reversed phase polystyrene divinylbenzene chromatographic support HP20ss followed by normal phased HPLC using a luna silica column. The structures of the compounds were established though the interpretation of spectroscopic data. Activity testing was conducted against hESCs (BG02) with briareolate ester J showing no inhibition activity and briareolate ester K showing mild activity with an EC50 value of 25 (So(BM. These results confirm that the exact confirmation and existence of the (E,Z)-dienone is related to the activity that was observed with the previously isolated briareolate esters L and M.
69

Free Swimming Soft Robotic Jellyfish with Adaptive Depth Control

Unknown Date (has links)
This thesis is encompasses the design, construction, control and testing of an improvement upon the novel soft robotic Jennifish platform. The advancement of this platform includes the addition of light and depth sensors as well increasing the separation of tentacle groups from two to three sets. The final vehicle model consists nine PneuNetstyle actuators divided into three groups of three, molded around a machined Delrin pressure vessel. With a 12V submersible impellor pump connected to each actuator grouping, propulsion is created by the filling and emptying of these tentacles with surrounding ambient water. The Jellyfish2.0 is capable of omnidirectional lateral movement as well as upward driven motion. The vehicle also has a temperature sensor and IMU as did the previous of this platform. Qualitative free-swimming testing was conducted, recorded and analyzed as well as quantitative inline load cell testing, to create a benchmark for comparison with other jellyfish like robots. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection
70

Population Structure and Gene Expression of the Coral Montastraea cavernosa in the Northern Florida Reef Tract

Unknown Date (has links)
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. 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. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

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