Patterns of settlement of larvae and population dynamics of juveniles are poorly known for coral reef fishes. During 1987 to 1989, I studied these phenomena in the domino damselfish (Dascyllus albisella), a species endemic to the Hawaiian Islands. Larvae settle onto branching coral heads as new recruits (10-15 mm in length), usually with conspecific groups, and remain on the coral heads through juvenile life until maturity (70 mm total length). By conducting experiments on natural patch reefs and on an artificially distributed grid of coral heads, I found that most larvae settle at night, and that they settle preferentially on corals supporting large conspecific groups compared to small groups or empty corals. Within a group, juveniles form a linear dominance hierarchy based on fish size; aggressive interactions are mainly directed by larger fish towards smaller fish. Tagging studies demonstrated that growth was retarded in larger groups and for fish of low social status, but that survival, especially of new recruits, was enhanced in larger groups. Therefore, I identified both a growth cost and a survival benefit to group living. I derived a measure of net benefit of group living by combining size-specific growth and survival data into an estimate of the probability of reaching mature size. This estimate increased with group size in 1988 but not in 1987. I developed a simulation model which used my field data on settlement rate, settlement preferences, and juvenile growth and survival to predict demography of juvenile groups. The model successfully predicted seasonal fluctuations in mean group size, and estimated the number of fish maturing in 1987 and 1988, as a function of settlement rate and preferences and of juvenile growth and survival. Numbers maturing were directly related to settlement rate in both years, except at high rates in 1987, suggesting that primary recruitment limitation of adult numbers could be occurring. Settlement preferences also influenced numbers maturing. At all settlement rates, numbers maturing differed between years, suggesting that secondary recruitment limitation of adult numbers may also occur. / Graduation date: 1991

In Hawaii, abundance of the scleractinian Fungia scutaria is thought to have been in decline in recent years due to disturbances to Kaneohe Bay, where an unusually dense population exists. This study examines factors that could limit population growth in this coral. Sexual reproduction occurred throughout the summer. Experimental data from sperm dilution studies suggested that eggs must be released within 2m of a spawning male for successful fertilization to occur. Field surveys indicated that many patch reefs exhibited high enough densities to yield successful fertilization. However, since field surveys found that only a small percentage (1 %) of juvenile corals (5 cm in length) resulted from settled larvae, post-fertilization processes may be limiting successful recruitment. Asexual reproduction appears to be dominant, with 70% of corals occurring in close aggregations, and 93% of these in aggregations made up of a single color-morph. / Thesis (M. A.)--University of Hawaii at Manoa, 2000. Includes bibliographical references (leaves 70-74).

Thesis (M.S.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 43-44). / vi, 44 leaves, bound ill. (some col.) 29 cm

Missing leaves: 170. / Mode of access: World Wide Web. / Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 190-203). / Electronic reproduction. / Also available by subscription via World Wide Web / xvi, 203 leaves, bound ill. (chiefly col.), col. maps 29 cm

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 91-96). / vi, 149 leaves, bound ill., map 29 cm

Thesis (Ph.D.)--University of Hawaii at Manoa, 1994. / Includes bibliographical references (leaves 235-249). / Microfiche. / xx, 249 leaves, bound ill., maps 29 cm

Analysis of the pattern of zonation of reef corals off the Kona coast of Hawaii revealed the existence of four clearly defined zones. This pattern was confirmed at three sites where corals were counted using a series of 45 meter long transects running parallel to shore from depths of 3 to 40 meters. Clustering analysis dendrographs, spatial changes in illumination and rates of water movement, as well as growth and survival of coral transplants also confirmed the zonation pattern. Each of the four zones is characterized by a dominant coral species, substratum type, depth, and range of physical conditions. Each zone also appears to be in a different stage of community succession due to the frequency of large scale environmental disturbances from winter storm waves. The shallowest zone begins at the base of the shoreline cliff, ranges in depth from 2.5 to 8 meters, and has a bottom cover consisting mainly of irregularly shaped basaltic boulders; Pocillopora meandrina dominates coral cover in this zone. This species appears to be the first to colonize new substrata and persists in large numbers only in the near-shore boulder zone where mechanical stress from wave action is great enough to restrict the growth forms of more competitive species. Due to this high wave stress, the P. meandrina bolder zone appears to be in an early successional stage with low coral cover and dominance and relatively hiqh species diversity. Moving into deeper water the Porites lobata reef building zone ranges in depth from 6 to 14 meters and is characterized by a gently sloping solid basalt and limestone bottom. Porites lobata dominates coral cover by growing in massive lobed and encrusting colonies. While succession seems to be in an advanced stage, monopolization of available space does not appear to be complete enough to exclude a variety of less competitive species, resulting in relatively high species diversities. The third zone occurs on the reef slope and ranges in depth from 14 to 30 meters. Solid substrata is scarce and succession may be a late stage due to domination of bottom cover by thickets of Porites compressa. Most of the other species that persist in this zone avoid competitive interactions by growing above the level of P. compressa. Storm wave stress is most devastating to corals in this zone, and breakage of living colonies seems to increase diversity by reducing P. compressa dominance. Transport of living coral fragments appears to extend zonal boundaries and create new colonies. Extensive "rubble channels" occur in this zone, and these channels may get progressively larger due to churning of rubble fragments with each successive storm. The Porites lobata rubble zone occurs below the deep border of the P. compressa thickets and extends to approximately 50 meters, the depth at which coraIs cease to appear. Substrata consists mostly of fine sand and a variety of small encrusting corals are found growing on scattered rubble fragments. Specialized species with narrow physiological tolerances limited to this zone also increase species diversity. While maximum size of corals may be reduced in this zone due to low light intensity, lack of solid substrata probably determines the lower depth limit of coral occurance. Sand and rubble that is carried downslope during storms cause this zone to be physically unstable and succession appears to be constantly interrupted at early stages. This is in contrast to other deep reef areas, such as off Maui and the Red Sea, where substrata is solid to the depth limit of coral growth. These communities appear to be highly stable and diverse, and in late or climax stages. The depauperate nature of Hawaiian coral fauna is probably due to fairly rigorous environmental conditions in combination with difficulties in larval transport from coral evolutionary centers in the western Pacific. However, reef areas off Kona are relatively rich for Hawaii due to complete protection from tradewind generated seas, partial protection from long period north swells, and the steep nearshore slopes that extend below wavebase. / Typescript. Bibliography: leaves 173-181.

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 102-127). / ix, 127 leaves, bound ill., maps 29 cm

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 89-96). / ix, 96 leaves, bound ill. 29 cm

The coral reefs of Kane'ohe Bay, on the windward coast of O'ahu, Hawai'i, have changed markedly over the last half century. Some of the most spectacular coral reefs in Hawai'i were reported from Kane'ohe Bay in the late 1800's and early 1900's, but with the beginning of extensive military dredge and fill operations during the World War IT era, conditions in the bay began to change dramatically. After the War, rapid urbanization of the area began and conditions in the bay continued to decline until pressure from the public and scientific community led to the diversion of the large sewage discharges in the southeast lagoon to a newly built deep ocean outfall outside the bay in 1977-1978. Although conditions temporally improved, recent surveys indicate that current conditions in the bay are not as favorable as expected. This study provides a time series analysis of changes in coral and algae cover in Kane'ohe Bay based upon a series of coral reef surveys conducted throughout the bay in 1970171, 1983, and 1990. Beginning in 1970171, conditions in the bay were highly degraded and scientists speculated that eutrophication and sedimentation, as a result of urbanization and construction, were the primary cause of an observed decline in lagoon corals communities in the southeast lagoon and an explosive growth of the green "bubble algae", Dictyosphaeria cavemosa, which was smothering corals in the middle lagoon. In . 1983, six years after major sewage discharges were diverted from the bay, surveys indicated dramatic improvements in water quality and the reefs showed signs of recovery. D. cavemosa algae levels, associated with earlier nutrient pollution, plummeted to less than twenty percent of their former abundance levels and coral cover increased by over two hundred percent. Although it was predicted that the coral reefs of Kane'ohe Bay would continue to recover, surveys in 1990 indicate that coral recovery slowed or ceased and the growth of the green "bubble algae", D. cavemosa, more than doubled compared to 1983 levels. In addition to the failure of the t~o dominant coral species Porites compressa and Montipora capitata to continue to recover, almost all of the less common coral species including Pocillopora damicomis, Fungia scutaria, Cyphastrea ocellina, and some others, showed significant declines in reef cover. Although this study was not able to detennine the exact causes of the observed changes in Kane'ohe Bay, it is suggested that high nutrient inputs provided favorable conditions for the changes in coral and algae cover. High nutrient levels are thought to have been derived from a number of sources including chronic sewage pollution, increased sedimentation from runoff, and reef kills associated with acute but large episodes of freshwater runoff. Some of these nutrient inputs may have been the result of non-point source and point source sewage pollution derived from leaky sewer lines, cesspool and septic tank discharges, commercial tour and recreational boat waste discharges, and periodic sewage bypasses from municipal wastewater treatment plants and sewage pump stations. Other nutrients may have been derived from increased sedimentation following extensive land clearance, land development, and highway construction. Additional factors may include a decrease in herbivorous fish species owing to over fishing and the ability of D. cavemosa algae to concentrate nutrients from underlying substrates and excretion from infaunal organisms. Other factors such as increased nutrient recycling from the sediments, possible increased nitrogen fixation from reefs, and natural fluctuations in relative species abundances may also be responsible for some of the observed changes in coral reef community structure. Although rare, the largest nutrient fluxes followed the catastrophic freshwater reef-kill events caused by severe rainstorms in conjunction with low tides and low wind conditions in 1965 and 1987-1988. Although the cause and effect relationship is still uncertain, the highest levels of Dictyosphaeria cavemosa algae ever recorded in Kane'ohe Bay occurred in the years following these storm events. Results of this study indicate that further research is needed to monitor ongoing conditions in the bay and determine what is preventing the reef ecosystem from returning to its former more pristine condition. Because water quality parameters generally remained the same or improved compared to previous polluted conditions, it is suggested that current measures of water quality are not reliable in forewarning against coral reef degradation in Kane'ohe Bay. Although a reduction in all future development in and around the bay would probably help maintain environmental conditions at the status quo, additional regulations and enforcement may be needed to help reduce disturbances caused by existing land and water use. It is suggested that a reduction in nutrient inputs to the bay would be beneficial to reef corals. Recommendations made by the Kane'ohe Bay Task Force outlined in the Kane'ohe Bay Master Plan should serve as a model and be implemented as soon as possible. Continuing assessment of the Kane'ohe Bay coral reef ecosystem and surrounding watershed will then need to be made on a regular basis to ensure that further degradation of the reefs is not occurring. / Thesis (M. A.)--University of Hawaii at Manoa, 1995. Includes bibliographical references (leaves 166-175).