published_or_final_version / Zoology / Master / Master of Philosophy

published_or_final_version / Biological Sciences / Master / Master of Philosophy

A 3-dimensional individual-based model, the ReefModel, was developed to simulate the interaction among six functional groups of coral reef organisms (tabular coral, foliaceous coral, massive coral, macroalga, corallivorous gastropod and herbivorous fish) using an object-oriented technique. The simulation results suggest that (i) fast-growing habit with overtopping competitive mechanism is effective for corals to gain dominance in a stable coral community; (ii) the integration of physical disturbance and the differential responses of corals play an important role in structuring coral communities; (iii) macroalgal influence can cause significant shift in coral community structure, but the influence can be mediated by herbivory; (iv) gastropod predation provides differential effects on different coral groups; (v) alternative stable states can occur in coral reef communities and result from the influence of small random spatial events that occur early on during the interactions among the reef organisms. / A two year (1997--1999) monitoring programme of the coral communities at two sites, A Ma Wan (AMW) and A Ye Wan (AYW), in Tung Ping Chau, Hong Kong was carried out. The study identified a total of 45 scleractinian coral species in the study areas, in which 40 species were recorded in AMW and 32 species were recorded in AYW. Multidimensional Scaling (MDS) ordinations showed that distinct spatial variations occurred in the coral communities within and between sites and were probably due to the differential effects of the repeated severe cyclone impacts on the communities. The seasonal influence of corallivorous gastropods (Drupella rugosa and Cronia margariticola ) and macroalgae also caused substantial decrease in percent cover of various dominant species in the communities. / Another two year (1998--1999) monitoring programme on the reef fish communities in the study areas was also carried out. The study identified a total of 106 species in the study areas, in which 87 species were recorded in AMW and 78 species were recorded in AYW. A seasonal pattern was observed in the abundances and species richness of all fishes and of most of the frequently encountered families/trophic groups in both study areas. This pattern may be related to the seasonal fluctuation of macroalgae, the influence of recruitment and post-settlement of fish larvae, and the seasonal variation in the behaviour of fishes. MDS ordinations demonstrated that spatial variation in fish community structure existed within and between sites and were possibly related to the spatial variation of the coral community structure therein. The ordinations also showed that the fish community structures were not seasonally stable throughout the study period. / Coral reef communities have high ecological and economic values but are under increasing human-induced stress locally and worldwide. Long-term monitoring of the communities is thus essential to understand the natural variation of the communities in order to provide objective assessment on the impacts of human on them. Furthermore, anthropogenic disturbances are known to cause phase shifts of coral reef communities that suggests the potential existence of alternative stable states in these communities. Examining this diagnosis by modelling studies is important for their conservation. / In conclusion, the coral communities in Tung Ping Chau, Hong Kong may have low resilience towards severe disturbances. Preserving the coral resilience should be one of the main goals of any strategy aimed at conserving the coral communities around the island. Precautionary principle should also be adopted in their conservation as the alternative stable states may appear in the communities after exposure to human or naturally induced disturbances. / Tam Tze Wai. / "April 2006." / Adviser: Put O. Ang, Jr. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6168. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 199-211). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Lau, Pui Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 84-94). / Abstracts in English and Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.v / Acknowledgements --- p.ix / Contents --- p.x / List of Figures --- p.xiv / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Regulations of gametogenesis and mass spawning in corals --- p.1 / Chapter 1.1.1 --- Endogenous cues --- p.2 / Chapter 1.1.2 --- Environmental cues --- p.3 / Chapter 1.2 --- Studies on black corals --- p.5 / Chapter 1.2.1 --- Introduction of black corals --- p.5 / Chapter 1.2.2 --- Black corals harvesting --- p.6 / Chapter 1.2.3 --- Biodiversity and distribution of black corals in Chinese and Hong Kong waters --- p.8 / Chapter 1.2.4 --- Threats to black corals --- p.9 / Chapter 1.3 --- Significance and objectives of the present study --- p.11 / Chapter 1.3.1 --- Objectives --- p.12 / Chapter 1.3.2 --- "The targeted species, Antipathes curvata and the study site" --- p.13 / Chapter 1.4 --- Thesis outline --- p.14 / Chapter Chapter 2 --- "Reproductive Biology of Antipatharian Black Coral, Antipathes curvata in Lan Giio Shui, Hong Kong" / Chapter 2.1 --- Introduction --- p.18 / Chapter 2.1.1 --- Coral Reproduction --- p.20 / Chapter 2.1.2 --- Sexual reproduction in black corals --- p.21 / Chapter 2.2 --- Materials and methods --- p.24 / Chapter 2.2.1 --- Sample collections and pre-treatment --- p.24 / Chapter 2.2.2 --- Histological processing --- p.25 / Chapter 2.2.3 --- Light microscopy --- p.26 / Chapter 2.2.4 --- Gametogenesis --- p.27 / Chapter 2.2.5 --- Environmental and statistical analysis --- p.27 / Chapter 2.3 --- Results --- p.28 / Chapter 2.3.1 --- General reproductive mode --- p.28 / Chapter 2.3.2 --- "Sex ratio, size at sexual maturity and density of gamete" --- p.28 / Chapter 2.3.3 --- Characteristics of polyps and gametes of A. curvata --- p.29 / Chapter 2.3.4 --- Changes in geometric diameter of gametes overtime --- p.30 / Chapter 2.3.5 --- Developmental stages of gametogenesis --- p.31 / Chapter 2.3.5.1 --- Oogenesis --- p.31 / Chapter 2.3.5.2 --- Spermatogenesis --- p.32 / Chapter 2.3.6 --- Development of oocytes and spermaries over time --- p.34 / Chapter 2.3.7 --- Correlation of black coral reproduction with seawater temperature --- p.35 / Chapter 2.3.8 --- Gametogenesis in individual colonies --- p.36 / Chapter 2.3.8.1 --- Female colonies --- p.37 / Chapter 2.3.8.2 --- Male colonies --- p.39 / Chapter 2.4 --- Discussion --- p.40 / Chapter 2.4.1 --- Asynchronization of gametogenic cycle --- p.40 / Chapter 2.4.2 --- Possible effect of seawater temperature on reproduction of A. curvata --- p.43 / Chapter Chapter 3 --- Detection of the Sex Steroid 17β-estradiol and its Possible Roles on Gametogenesis in Black Corals Antipathes curvata from Hong Kong / Chapter 3.1 --- Introduction --- p.55 / Chapter 3.1.1 --- "Roles of sex hormone, 17(3-estradiol (E2) in the reproduction of vertebrates" --- p.58 / Chapter 3.1.2 --- Roles of vertebrate-type sex steroids in Cnidaria --- p.59 / Chapter 3.2 --- Materials and methods --- p.63 / Chapter 3.2.1 --- Study site --- p.63 / Chapter 3.2.2 --- 17β-estradiol (E2) extraction --- p.63 / Chapter 3.2.3 --- 17β-estradiol (E2) assay --- p.65 / Chapter 3.2.4 --- Calculation and assay validation --- p.65 / Chapter 3.2.5 --- Gametogenesis of A. curvata --- p.66 / Chapter 3.2.6 --- Seawater temperature and statistical analysis --- p.67 / Chapter 3.3 --- Results --- p.67 / Chapter 3.3.1 --- Seasonal profile of E2 --- p.67 / Chapter 3.3.2 --- Gametogenesis --- p.68 / Chapter 3.3.3 --- Correlation with seawater temperature --- p.69 / Chapter 3.4 --- Discussion --- p.70 / Chapter Chapter 4 --- Summary and Perspectives --- p.78 / References --- p.84

Choi Mei Mei. / Thesis submitted in: December 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 214-236). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.vi / Table of Contents --- p.viii / List of Tables --- p.xi / List of Figures --- p.xii / Chapter Chapter One: --- General Introduction --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- Coral bleaching --- p.2 / Chapter 1.1.2 --- Predation of corals by corallivorous gastropods --- p.20 / Chapter 1.2 --- Introduction of Study Sites- Tung Ping Chau --- p.33 / Chapter 1.3 --- Objectives of the Study --- p.35 / Chapter 1.4 --- Structure of this Thesis --- p.36 / Chapter Chapter Two: --- "Coral Bleaching and Predation by Corallivorous Gastropods in the Coral Communities of A Ye Wan and A Ma Wan, Tung Ping Chau" --- p.40 / Chapter 2.1 --- Introduction --- p.40 / Chapter 2.2 --- Materials and Methods --- p.45 / Chapter 2.2.1 --- Quantitative surveys --- p.45 / Chapter 2.2.2 --- "Quantifying the colour of corals, Porites lobata, in Tung Ping Chau" --- p.47 / Chapter 2.2.3 --- Physical parameters --- p.49 / Chapter 2.2.4 --- Data and statistical analysis --- p.49 / Chapter 2.3 --- Results --- p.50 / Chapter 2.3.1 --- Live coral coverage in A Ye Wan and A Ma Wan --- p.50 / Chapter 2.3.2 --- Proportion of Porites lobata paled --- p.52 / Chapter 2.3.3 --- Changes in colour intensity of Porites lobata between seasons --- p.54 / Chapter 2.3.4 --- Density of corallivorous gastropods --- p.55 / Chapter 2.3.5 --- Percentage coverage of live and dead Acropora tumida --- p.55 / Chapter 2.3.6 --- Physical parameters --- p.57 / Chapter 2.4 --- Discussion --- p.59 / Chapter 2.4.1 --- Live coral cover in A Ye Wan and A Ma Wan --- p.59 / Chapter 2.4.2 --- Bleaching of Porites lobata in summer and winter --- p.61 / Chapter 2.4.3 --- Colour intensity of Porites lobata in different seasons --- p.67 / Chapter 2.4.4 --- Predation on corals by corallivorous gastropods --- p.69 / Chapter Chapter Three: --- "Study on Coral Bleaching, Pontes bbata, in Tung Ping Chau by using Permanent Quadrats" --- p.103 / Chapter 3.1 --- Introduction --- p.103 / Chapter 3.2 --- Materials and Methods --- p.104 / Chapter 3.2.1 --- Study sites --- p.104 / Chapter 3.2.2 --- Permanent quadrat monitoring --- p.105 / Chapter 3.2.3 --- Corals sampling for zooxanthellae density and chlorophyll a concentration analysis --- p.106 / Chapter 3.2.3.1 --- Tissus collection --- p.106 / Chapter 3.2.3.2 --- Zooxanthellae counting --- p.107 / Chapter 3.2.3.3 --- Chlorophyll a determination --- p.107 / Chapter 3.2.3.4 --- Determination of coral surface area --- p.108 / Chapter 3.2.4 --- Data analysis --- p.108 / Chapter 3.3 --- Results --- p.109 / Chapter 3.3.1 --- Monitoring of bleaching of porties lobata in permanent quadrat --- p.109 / Chapter 3.3.2 --- Density of Zooxanthellae in Porites lobata --- p.111 / Chapter 3.3.3 --- Concentration of Chlorophyll a in Porites lobata --- p.112 / Chapter 3.3.4 --- Chlorophyll a per zooxanthellae --- p.113 / Chapter 3.4 --- Discussion --- p.114 / Chapter Chapter Four --- Study of Predation on coral Acropora tumida by Corallivorous Gastropods in Tung Ping Chau --- p.138 / Chapter 4.1 --- General Introduction --- p.138 / Chapter 4.2 --- Materials and Methods --- p.140 / Chapter 4.2.1 --- Study sites --- p.140 / Chapter 4.2.2 --- Preliminary evaluation of corallivorous gastropods as the coal predator --- p.141 / Chapter 4.2.3 --- Monthly monitoring of permanent quadrat --- p.142 / Chapter 4.2.4 --- Data and statistical analysis --- p.144 / Chapter 4.3 --- Results --- p.145 / Chapter 4.3.1 --- Species of corallivorous gastropods in Tung Ping Chau --- p.145 / Chapter 4.3.2 --- Feeding behavior of corallivorous gastropods in Tung Ping Chau --- p.146 / Chapter 4.3.3 --- Density of corallivorous gastropods --- p.147 / Chapter 4.3.3.1 --- Monthly change in density of corallivorous gastropods --- p.147 / Chapter 4.3.3.2 --- Correlation between gastropod density and temperature --- p.149 / Chapter 4.3.4 --- Cumulative percentage of area of feeding scar over time --- p.149 / Chapter 4.3.5 --- Monthly percentage change in the areas of feeding scar --- p.152 / Chapter 4.3.5.1 --- Monthly percentage change in the areas of feedling scar due to predation by Cronia margariticola and Drupella rugosa --- p.152 / Chapter 4.3.5.2 --- Correlation between gastropod density and monthly percentage change in area of scar --- p.153 / Chapter 4.3.5.3 --- Correlation between temperature and monthly percentage in area of the feeding scar --- p.154 / Chapter 4.3.6 --- Rate of predation --- p.154 / Chapter 4.3.6.1 --- Rate of predation by the corallivorous gastropods --- p.154 / Chapter 4.3.6.2 --- "Correlation between rate of predation, gastropod density and seawater temperature" --- p.155 / Chapter 4.3.7 --- Population size structure of the corallivorous gastropods --- p.156 / Chapter 4.3.7.1 --- Population size structure of Cronia margariticola --- p.156 / Chapter 4.3.7.2 --- Population size structure of Drupella rugosa --- p.158 / Chapter 4.4 --- Discussion --- p.159 / Chapter 4.4.1 --- Feeding behaviours of corallivorous gastropods --- p.159 / Chapter 4.4.2 --- Density of corallivorous gastropods --- p.162 / Chapter 4.4.3 --- Cumulative percentage of area of feeding scar --- p.170 / Chapter 4.4.4 --- Monthly percentage change of area of feeding scar --- p.173 / Chapter 4.4.5 --- Rate of predation --- p.175 / Chapter 4.4.6 --- Size structure of population size --- p.178 / Chapter 4.4.7 --- Predatory pressure from corallivorous gastropods in Tung Ping Chau --- p.185 / Chapter Chapter Five --- Summary and Perspectives --- p.207 / References --- p.214

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Tsang, Yu Man. / "November 2009." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 268-277). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.iii / Content --- p.vii / List of Tables --- p.ix / List of Figures --- p.xx / Chapter Chapter One --- General Introduction --- p.1 / Introduction --- p.1 / Coral Reefs --- p.1 / Coral-Algal Symbiosis --- p.2 / The Dinoflagellate Symbiodinium --- p.11 / Coral Communities in Hong Kong --- p.18 / Objectives --- p.21 / Study Sites - Tung Ping Chau Marine Park --- p.21 / Coral Species chosen for the Experiment --- p.23 / Platygyra acuta --- p.23 / Porites lutea --- p.23 / Thesis Outline --- p.24 / Chapter Chapter Two --- Temporal variation in photophysiological parameters of Hong Kong corals and their relationship with the environmental factors --- p.28 / Introduction --- p.28 / Methods and Materials --- p.33 / Study Sites --- p.33 / Coral Sampling for zooxanthellae density and chlorophyll concentration analysis --- p.34 / Measurement of changes in the photosynthtic activity of the corals --- p.38 / Environmental Factors --- p.38 / Data analysis --- p.39 / Results --- p.41 / Density of Zooxanthellae --- p.41 / Concentrations of Chlorophyll a and c2 (per zooxanthella) --- p.43 / Concentrations of Chlorophyll a and c2 (per surface area) --- p.46 / Chlorophyll ratio --- p.49 / Effective quantum yield --- p.51 / Photosynthetically active radiation (PAR) --- p.54 / Intra-colony variation for Platygyra acuta --- p.56 / Comparison between Platygyra acuta and Porites lutea --- p.64 / Environmental factors and their correlations with photophysiological parameters in corals --- p.68 / Discussion --- p.73 / Density of zooxanthellae --- p.74 / Concentrations of Chlorophyll a and c2 --- p.80 / Chlorophyll ratio --- p.85 / Effective quantum yield --- p.88 / Intra-colony variation --- p.94 / Between species comparison --- p.98 / Summary --- p.107 / Chapter Chapter Three --- PCR-RFLP Analysis on Symbiodinium in Platygyra acuta --- p.241 / Introduction --- p.241 / Methods and Materials --- p.244 / Sample collection --- p.244 / Molecular phylotyping --- p.245 / Results --- p.247 / Discussion --- p.249 / Summary --- p.257 / Chapter Chapter Four --- Summary and Conclusion --- p.262 / References --- p.268