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Genetic assessment of connectivity in the temperate octocorals Eunicella verrucosa and Alcyonium digitatum in the NE AtlanticHolland, Lyndsey Paula January 2013 (has links)
Elucidating patterns of connectivity for species of conservation concern is crucial in the design of networks of ecologically coherent marine protected areas, and therefore is considered in the design of such a network recently proposed to the UK Government. However, data concerning connectivity are deficient for most invertebrate sessile taxa. Therefore, this study used microsatellite panels developed de novo to assess the population genetic structure and genetic connectivity of two temperate octocorals in the North East Atlantic. Microsatellite panels for both species show evidence of cross-species transferability, and therefore in future may prove to be useful monitoring tools for the target species but also for congenerics further afield in Europe. Eunicella verrucosa (O. Alcyonacea: S.O.Holaxonia: F. Gorgoniidae), a threatened and IUCN red-listed sea fan, was sampled in the northerly extremes of its eastern Atlantic range in southern Portugal, Brittany, the South West UK and western Ireland. In this vicinity, connectivity appears to be defined at regional scales and localised cases of inbreeding and differentiation suggest that the population structure of this species is best described as a metapopulation. Alcyonium digitatum (O. Alcyonacea: S.O. Alcyoniina: F. Alcyoniidae), a soft coral, was sampled in the central portion of its range in Brittany, western Ireland, south west UK and the North Sea. This species exhibited very little population structure and apparent panmixia across the sampled range. However, high levels of heterozygote deficiencies and inbreeding in the majority of populations implies that the genetic structure of some populations of this species may be defined by self-seeding and rarer dispersal events that occur sufficiently often to offset divergence via genetic drift. Coalescent analyses indicate that in both species, migration between regions occurs asymmetrically. The presence of few duplicate genotypes in both datasets implies that sexual reproduction predominates in both species in the sampled area. Eunicella verrucosa is a charismatic species that is often used to promote marine conservation efforts in the UK and A. digitatum is a ubiquitous animal around western European coasts; the two species often occur together and both may suffer the damaging effects of mobile fishing gears. This research represents the first population genetic assessment of both species and the first time microsatellites have been used to assess population structure of octocorals in the North East Atlantic.
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Count or Pointcount: Is Percent Octocoral Cover an Adequate Proxy for Octocoral Abundance?Lybolt, Matthew J 04 April 2003 (has links)
The Florida Keys Coral Reef Monitoring Project (CRMP) began video transect sampling in 1996 and has continuously monitored 107 Florida Keys stations through 2002. The video was downward pointing and produced images from which planar projection data were calculated to determine percent cover of living benthic organisms. An absence of data assessing correlation between octocoral percent cover and octocoral abundance motivated a study to compare octocoral percent cover with abundance data acquired from the same video transects. The methods employed to extract octocoral abundance data from videotape were validated. Temporal changes in octocoral abundance, size and taxonomic group were determined by examination of video transects of 28 randomly selected stations from 1996, 1998, 1999, and 2002. Size classes were defined as40cm (short, medium and tall respectively). Taxonomic groups were Gorgonia ventalina and "other octocorals" in three size classes, and Scleraxonia. An in situ study assessed the accuracy of video-derived counts.
Average densities of G. ventalina and Scleraxonia were consistently about one colony/m2. Other octocoral as a group averaged 7-9 colonies/m2. When summarized by height, short and tall averaged about 1-2 colonies/m2, while colonies between 10 and 40 cm in height consistently averaged about 6 colonies/m2.
Hurricane Georges, in September 1998, impacted the octocoral assemblage. Abundance declined most at stations near the storm center and stations in shallower water. Storm impact was related to octocoral height. Tall octocorals were removed more frequently than medium, short and encrusting forms. A dramatic increase of short individuals in 2002 is indicative of successful post-hurricane recruitment. By 2002, octocoral abundance had recovered to pre-hurricane levels.
This study demonstrated that abundance data can reliably be derived from archived video data, reinforcing the value of standardized video data archives. Octocoral abundance and octocoral percent cover are not strongly correlated because tall individuals disproportionately influence percent cover estimates. Nevertheless, trends in octocoral percent cover are reliable indicators of the trends in octocoral abundance.
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Survivorship, Growth, and Fecundity of Eunicea flexuosa (Cnidaria: Octocorallia) TransplantsEspitia, Paola G. 01 December 2013 (has links)
Octocorals are important components of many reef benthic communities, and efforts to restore populations following damage events and relocating colonies preceding permitted activities is becoming part of regulatory processes. Because many octocorals have regenerative capabilities ideal for removing branch clippings (fragments), they may make excellent donors, sources of transplants, for restoration efforts. This study examined the effect of fragment size, fragmentation timing, and transplantation on the survivorship, growth, and fecundity of Eunicea flexuosa clippings and donor colonies. Eunicea flexuosa clippings 20 cm in height were transplanted to a ship grounding site offshore southeast Florida in April 2010 and November 2010. Data collected during the June through September spawning months in 2010 and 2011 revealed high survivorship among all transplants (85%), however partial mortality from encrustation by bio-fouling organisms ensued. Growth rates among donor colonies was high. The fecundity of fragments transplanted in May was not negatively affected in 2010; however the fecundity of all transplants was lower than that of donor colonies in 2011, with oocytes failing to reach reproductive size. Re-allocation of energy resources towards tissue repair may account for the low growth and loss in fecundity. This study highlights the importance of evaluating fragment size and collection time in promoting growth and propagation of transplanted octocorals following damage and prior to marine construction events.
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Characterization of Bacterial Diversity in Cold-Water Anthothelidae CoralsLawler, Stephanie Nichole 18 March 2016 (has links)
Cold-water corals, similar to tropical corals, contain a diverse and complex microbial landscape. Comprised of vital microscopic organisms (i.e. bacteria, viruses, archaea), the coral microbiome is a driving factor in the proliferation and survival of the coral host. Bacteria provide essential biological functions within coral holobionts, facilitating increased nutrient utilization and production of antimicrobial compounds. To date, few cold-water octocoral species have been analyzed to explore the diversity and abundance of their microbial associates. For this study, 23 samples of the family Anthothelidae were collected from Norfolk (n = 12) and Baltimore Canyons (n = 11) from the western Atlantic in August 2012 and May 2013. Genetic testing found that these samples comprised two Anthothela species (Anthothela grandiflora and Anthothela sp.) and a new genus. DNA was extracted and sequenced with primers targeting the V4-V5 variable region of the 16S rRNA gene using 454 pyrosequencing with GS FLX Titanium chemistry.
Results demonstrated that the host genus was the primary driver of bacterial composition. The new coral genus, dominated by Alteromonadales and Pirellulales, had much higher species richness and a distinct bacterial community compared to Anthothela samples. Anthothela species had very similar bacterial communities, dominated by Oceanospirillales and Spirochaetes. Core bacterial diversity present across 90% of the Anthothela samples revealed genus-level conservation. This core included unclassified Oceanospirillales, Kiloniellales, Campylobacterales, and Spirochaeta; the functional abilities of which contribute to a nearly complete nitrogen cycle. Dominant bacterial members of the new coral genus also had functional capabilities in nitrogen cycling. Overall, many of the bacterial associates identified in this study have the potential to contribute to the acquisition and cycling of nutrients within the coral holobiont.
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Variation in Coral Recruitment and Juvenile Distribution Along the Southeast Florida Reef TractHarper, Leah M 01 December 2017 (has links)
Coral recruitment in Southeast Florida is being outpaced by mortality, resulting in population declines in many species. Identifying the coral species most likely to recruit and survive on Southeast Florida reefs and evaluating spatial variation in recruitment and survivorship is crucial for managing decreasing coral populations. This study focuses on 12 sites in Broward and Miami-Dade counties that have served as long-term stations for monitoring adult coral cover and demographics. At each site, thirty-two 225cm2 grooved terracotta settlement tiles were attached to the substrate in winter of 2015 and retrieved in winter of 2016 to evaluate scleractinian and octocoral recruitment rates. Thirty-two corresponding 0.25 m2 quadrats were surveyed in situ for coralsconditions, such as Poritidae, Siderastreidae, and Octocorallia, exhibit signs of recruitment success and/or juvenile survivorship. Scleractinian recruitment was not variable spatially, but juvenile densities varied on site-level spatial scales, suggesting that differential survivorship structures adult scleractinian communities. This study will inform reef management and restoration efforts within Southeast Florida by identifying sites and species with potential to recover from disturbance through natural recruitment processes.
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Ecological and physiological constraints of deep-sea corals in a changing environmentGomez, Carlos E January 2018 (has links)
Deep-water or cold-water corals are abundant and highly diverse, greatly increase habitat heterogeneity and species richness, thereby forming one of the most significant ecosystems in the deep sea. Despite this remote location, they are not removed from the different anthropogenic disturbances that commonly impact their shallow-water counterparts. The global decrease in seawater pH due to increases in atmospheric CO2 are changing the chemical properties of the seawater, decreasing the concentration of carbonate ions that are important elements for different physiological and ecological processes. Predictive models forecast a shoaling of the carbonate saturation in the water column due to OA, and suggest that cold-water corals are at high risk, since large areas of suitable habitat will experience suboptimal conditions by the end of the century. The main objective of this study was to explore the fate of the deep-water coral community in time of environmental change. To better understand the impact of climate change this study focused in two of the most important elements of deep-sea coral habitat, the reef forming coral Lophelia pertusa and the octocoral community, particularly the gorgonian Callogorgia delta. By means of controlled experiments, I examined the effects of long- and short-term exposures to seawater simulating future scenarios of ocean acidification on calcification and feeding efficiency. Finally In order to understand how the environment influences the community assembly, and ultimately how species cope with particular ecological filters, I integrated different aspects of biology such functional diversity and ecology into a more evolutionary context in the face of changing environment. My results suggest that I) deep-water corals responds negatively to future OA by lowering the calcification rates, II) not all individuals respond in the same way to OA with high intra-specific variability providing a potential for adaptation in the long-term III) there is a disruption in the balance between accretion and dissolution that in the long term can shift from net accretion to net dissolution, and IV) there is an evolutionary implication for certain morphological features in the coral community that can give an advantage under stresfull conditions. Nevertheless, the suboptimal conditions that deep-water corals will experience by the end of the century could potentially threaten their persistence, with potentially negative consequences for the future stability of this already fragile ecosystem. / Biology
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Count or pointcount [electronic resource] : is percent octocoral cover an adequate proxy for octocoral abundance? / by Matthew J. Lybolt.Lybolt, Matthew J. January 2003 (has links)
Title from PDF of title page. / Document formatted into pages; contains 112 pages. / Thesis (M.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The Florida Keys Coral Reef Monitoring Project (CRMP) began video transect sampling in 1996 and has continuously monitored 107 Florida Keys stations through 2002. The video was downward pointing and produced images from which planar projection data were calculated to determine percent cover of living benthic organisms. An absence of data assessing correlation between octocoral percent cover and octocoral abundance motivated a study to compare octocoral percent cover with abundance data acquired from the same video transects. The methods employed to extract octocoral abundance data from videotape were validated. Temporal changes in octocoral abundance, size and taxonomic group were determined by examination of video transects of 28 randomly selected stations from 1996, 1998, 1999, and 2002. Size classes were defined as [10cm, 10-40cm, ]40cm (short, medium and tall respectively). / ABSTRACT: Taxonomic groups were Gorgonia ventalina and "other octocorals" in three size classes, and Scleraxonia. An in situ study assessed the accuracy of video-derived counts. Average densities of G. ventalina and Scleraxonia were consistently about one colony/m2. Other octocoral as a group averaged 7-9 colonies/m2. When summarized by height, short and tall averaged about 1-2 colonies/m2, while colonies between 10 and 40 cm in height consistently averaged about 6 colonies/m2. Hurricane Georges, in September 1998, impacted the octocoral assemblage. Abundance declined most at stations near the storm center and stations in shallower water. Storm impact was related to octocoral height. Tall octocorals were removed more frequently than medium, short and encrusting forms. A dramatic increase of short individuals in 2002 is indicative of successful post-hurricane recruitment. By 2002, octocoral abundance had recovered to pre-hurricane levels. / ABSTRACT: This study demonstrated that abundance data can reliably be derived from archived video data, reinforcing the value of standardized video data archives. Octocoral abundance and octocoral percent cover are not strongly correlated because tall individuals disproportionately influence percent cover estimates. Nevertheless, trends in octocoral percent cover are reliable indicators of the trends in octocoral abundance. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
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Omnifarious octocoral observations : ecology and genetics of octocoral communities from Útila, Bay Islands, HondurasLovenburg, Vanessa January 2016 (has links)
The Oxford English Dictionary defines 'omnifarious' as 'comprising or relating to all sorts or varieties', which quite accurately captures the very nature of octocorals and this thesis. The research reported here, aims to describe undocumented communities of coral reef organisms - the octocorals - which are an emergent dominant component within their threatened ecosystem of the Caribbean. Within the last four decades, coral reefs worldwide have experienced a precipitous plunge in many ecosystem services they provide, and most notably in the Caribbean. The foundation to reef resilience is structured on the ecosystem's ability to repair and restructure itself in the face of environmental shifts. These intricately complex strategies of resilience depend on repair mechanisms provided by a source of biodiversity, much of which remains poorly understood. This work explores many facets of the functioning within this potential future coral reef ecosystem. These reports are one of the most significant contributions to documenting and describing octocoral biodiversity (e.g. species, genetic, and community diversity) of the wider ecoregion of the Mesoamerican Barrier Reef System within the last three decades.
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