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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.
1

Change of benthic communities at Tiaoshi coral reef, southern Taiwan

Wu, Bing-je 27 August 2005 (has links)
Coral community at Tiaoshi in Nanwan Bay, southern Taiwan was originally dominated by branching Acropora corals which formed some monopolized patches. The community had been changed apparently on a local scale (<2 km) since 1994. Several Acropora patches were almost completely replaced by the solitary sea anemone Condylactis sp. after man-made and typhoon disturbances. However, sea anemones were apparently decreased in 2002. To understand the change of the benthic communities, three areas, including Anemone-dominated, Coral-recovery and Acropora-dominated, at depths of 6 to 10 m were selected and monitored by permanent transects from 2003 to 2005. Each site included three replicate patches. At Anemone-dominated area, the mean cover of sea anemone ranged from 24.6 to 15.3% and that of the hard corals was low with 1.4 to 3.9%. At Coral-recovery area, the mean cover of the hard corals was significantly increased from 21.3 to 38.9%, while macroalgae was significantly decreased from 20.7 to 6.1% and sea anemone was low with 1.4 to 3.0%. At Acropora-dominated area, the cover of the hard corals was ranged from 70.0 to 56.6% while macroalgae and anemone was 1.1 - 3.4% and 3.5 - 4.7%, respectively. In general, the results showed that anemone and macroalgae were decreased and corals were recovery. In addition, the diversity index of coral genera at Anemone-dominated area was higher due to coral recruitment in 2004 and 2005. The new recruits were dominated by Montipora stellata.
2

Tissue Loss Syndromes in Acropora cervicornis off Broward County, Florida: Transmissibility, Rates of Skeletal Extension and Tissue Loss

Smith, Abraham Jeffrey 01 December 2013 (has links)
The high latitude thickets of Acropora cervicornis off Broward County flourish despite the presence of natural and anthropogenic impacts. These populations provided a unique study area in contrast to disease-stricken populations of the Florida Keys. This study used time-sequenced photographs to examine how A. cervicornis was affected by tissue loss attributed to white-band disease during 2007–2008. Variables monitored included healthy colony skeletal extension rates, diseased colony skeletal extension rates, and tissue loss. The transmissibility of the three white-band syndromes found in the Scooter and Oakland thickets was examined through tissue grafting experiments. Skeletal extension rates of healthy and diseased colonies were generally not significantly different. Mean skeletal extension for A. cervicornis colonies in Broward County was observed to be 9.6 cm/y (SD=3.95, Range: 1.02–19.9). Mean linear tissue loss from disease signs was 2.6 mm/d (SD=4.3, Range: 0.023–16.8). Although the majority of active disease lesions caused severe tissue loss upon contact with healthy branches, in 25% of the cases there was no tissue loss. Disease signs were also observed in 10% of the control grafting trials. A. cervicornis thickets in Broward County were growing at rates similar to those observed in this species elsewhere in Florida, but faster than other areas of the Western Atlantic. Tissue loss rate from disease lesions was lower than reported elsewhere. White-band disease and/or other tissue loss syndromes are always present in Broward County, but the low prevalence of affected colonies, inconsistent transmission of a presumptive agent that causes the disease signs, and optimum branch skeletal extension seems to limit effects on the thickets. Results of this research are significant as the current protected status of acroporid corals no longer allows manipulative research such as coral grafting for transmissibility of potential disease pathogens.

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