Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 92-93). / ix, 93 leaves, bound col. ill. 29 cm

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 117-134). / x, 134 leaves, bound 29 cm

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 28-33). / 50 leaves, bound ill. 29 cm

Thesis (M.A.)--University of Hawaii at Manoa, 1993 / Pacific Islands Studies

Seventeen electromagnetic transient soundings were done on the lower east flank of Kilauea volcano, Hawaii. Each sounding is based on the response or the earth as a function of time to a step function of current in a horizontal linear source. Interpretation of these response measurements is usually done by matching the data to standard model curves or asymptotic expressions; however, these methods presuppose that each datum has been measured with a relative precision (e.g. a precision of 5%) whereas, sounding, each datum is commonly measured with an absolute precision (e.g. a precision of 10µv). Therefore, a general inversion technique based on linear comparisons between the data and model values was used for the interpretations of the data in this study. The resulting geoelectric model shows that the structure is uniform vertically to a depth of 1000 m below sea level. There are broad, but distinct, lateral variations in the interpreted conductivity values ranging from 0.10 to 0.16 -mho/m in most of east Puna to anomalous values of 0.30 to 0.50 mho/m in a particular area south of the rift at Puu Honuaula (see Figure 7). Based on these conductivity estimates, groundwater temperatures in the anomalous area are not expected to exceed 1500 C to depths of 1000 m below sea level. / ill / maps

Understanding gene flow, diversity, and dispersal patterns is important for predicting effects of natural events and anthropogenic activities on dolphin populations. With the very recent exceptions of false killer whales (Pseudorca crassidens), spinner dolphins (Stenella longirostris), and common bottlenose dolphins (Tursiops truncatus), Hawaiian odontocete species are managed as single stocks within the U.S. Hawaiian Exclusive Economic Zone. These exceptions are a result of recent studies that have indicated that some species have populations that show fidelity to individual islands or groups of islands, resulting in genetic differentiation, often with management implications. The first part of my study (following the introductory chapter) focused on population structure of pantropical spotted dolphins (Stenella attenuata) near the Hawaiian Islands. Because of the level of human interaction, pantropical spotted dolphin populations need to be defined accurately to be managed in a way that will avoid local population losses, especially given that the commercial and recreational troll fisheries near the islands "fish on dolphins" to catch tuna. I analyzed genetic samples for mtDNA and microsatellite loci from four island regions: Hawai'i, the 4-islands area, O'ahu, and Kaua'i/Ni'ihau. My results support genetic differentiation among the regions of Hawai'i, the 4-islands area, and O'ahu and suggest that pantropical spotted dolphins near Kaua'i/Ni'ihau are likely transient and in very low numbers. There was no strong evidence to support sex-biased dispersal or group fidelity. Possibly, differentiation is mediated by behavior adapted to differing habitat types. From a management perspective, spinner and bottlenose dolphin populations near the Hawaiian Islands have been split into separate stocks for management based on levels of genetic differentiation similar to those found for pantropical spotted dolphins. These precedents suggest that comparable action should be taken to split pantropical spotted dolphin stocks near the Hawaiian Islands. Most population studies rely heavily upon fixation indicies like FST to determine whether populations are genetically differentiated. When FST values are low but significantly different from zero, it can be difficult to interpret the biological significance of these values. As part of my study, I suggest that one way to evaluate whether small FST values indicate significant differentiation is to compare FST values with other populations considered to be separate based on factors such as extreme distance or morphological differences. I examined pantropical spotted dolphins from the coastal and offshore Eastern Tropical Pacificm (ETP), Hawaiian Islands, and China/Taiwan to examine the utility of comparing FST values across separate populations. Among Hawaiian Island regions, FST values are significantly different from zero but small. The comparison of these FST values with more distant populations in the ETP and China/Taiwan indicated that differences among Hawaiian Island regions were similar in magnitude to those found between the offshore and coastal ETP sub-species, but smaller than between the Hawaiian Island regions and the other regions examined. This suggests a level of reproductive isolation among the Hawaiian Islands regions that is comparable to that of offshore and coastal ETP populations, and supports the value of fixation index comparisons in evaluating differentiation among putative populations. My results suggest that assigning specific numerical baseline FST values may not always be biologically meaningful but that determining whether related populations with geographic or other separation show a preponderance of similar, lower, or higher fixation index values can help evaluate whether genetic differences among sympatric or parapatric groups warrants designating them as separate populations for management. Lastly, I explore whether the fast evolving mtDNA control region may be more suited to phylogenetic comparisons among the Stenella than slower evolving gene regions and whether the small number of haplotypes generally used in phylogenetic analyses is adequate for defining relationships among dolphins. Usually, slow evolving regions, such as gene regions, are used in phylogenetic analyses because species and genera have been isolated long enough for variation to have accumulated in such regions but not so long that many reversals (i.e. a mutational change in sequence that later changes back to the original sequence) have occured. The mtDNA control region is typically used for population genetic comparisons rather than phylogenetic comparisons because it is considered to be a fast evolving region. Historically, dolphin phylogeny has been examined using gene regions, which have resulted in ambiguous and unexpected relationships. However, the lack of variation in the mtDNA control region for pantropical spotted dolphin populations and the fact that recent studies have found that the mtDNA control region in cetaceans evolves at about one quarter the rate of other mammals, raises the question as to whether this region would be better suited to phylogenetic studies for the Stenella (and potentially other dolphin species). In comparing 346 haplotypes from five species of Stenella world-wide, I found that the mtDNA control region is probably not a good region to use for phylogenetic analyses, and that even faster evolving regions might perform better. The differences in the mtDNA control region were not sufficient to distinguish clear relationships among the Stenella. I also found that when subsets of haplotypes chosen at random were compared, the results differed among comparisons, suggesting that there is value in using more than the usual one or two haplotypes when making phylogentic comparisons. Given the recent increases in sequence availability (e.g. GenBank) and computing power, researchers should strongly consider using many haplotypes from a variety of populations in their phylogenetic comparisons.

Graduation date: 2005

Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 327-342). / Also available by subscription via World Wide Web / xxi, 342 leaves, bound 29 cm

The formation of novel ecosystems by non-native species poses management challenges that are both socially and ecologically complex. This complexity necessitates consideration of both ecological dynamics and social attitudes and perceptions. Red mangrove propagules were introduced to Moloka'i, Hawaii in 1902 to mitigate the effects of soil erosion and they have since spread along the coast and to adjacent islands creating novel habitat. Non-native mangroves in Hawai'i present a unique case study to examine diverse social attitudes and perceptions resulting from a long history of land cover transformations on the Hawaiian Islands, socio-cultural diversity of involved stakeholders, and the potential array of ecosystem services they may provide under changing land use and climatic conditions. Ecological dynamics were examined to (1) determine whether novel mangrove habitat affects zooplankton diversity and richness, (2) test the hypothesis that zooplankton community composition differs significantly among established mangrove and coastal non-mangrove habitat, and (3) assess other factors driving differences in zooplankton community assemblages. This study found no significant differences found between sites with and without mangroves in terms of richness, diversity, or community composition. However, lunar cycles and site dynamics, including fishpond structure, mangrove and open shoreline length, percentage of mangrove shoreline length, total percentage of carbon in mangrove leaves, and disturbance in the upstream watershed influenced zooplankton community composition. These findings suggest that non-native mangroves support community composition, richness, and diversity similar to non-mangrove areas, though some widespread taxa have lower abundances in mangrove habitat. My research suggests that in the face of declining fisheries, threatened reef habitat, and changing climate and ocean conditions, mangroves may provide zooplankton habitat in novel locations similar to that provided by native habitat, such that habitat availability for zooplankton is not hindered by non-native mangroves. To understand social dynamics 204 residents of Moloka'i, Hawaii were surveyed to evaluate: 1) attitudes and perceptions about this non-native species, 2) what factors influence these attitudes, and 3) how attitudes influence perceptions about management. A belief that mangroves should be removed, concern about threats to Moloka'i's coast, and not relying on mangroves for benefit were the primary drivers of negative attitudes towards non-native mangroves. Support for management actions was predicted by attitudes towards mangroves, perception and concern about threats to Moloka'i's coast, and experiences involving mangroves. I propose a framework for assessing and incorporating diverse perceptions and attitudes into decision-making around non-native species that have created novel ecosystems. An active management approach allowing mangroves to thrive in certain locations and to provide services such as habitat and crabbing access while in other locations limiting their extent to protect native bird habitat and cater for human needs, including safe beach and ocean access, may ultimately offer the greatest benefits to both the ecosystem and society. As environmental issues, such as species introductions, become increasingly complicated in the age of the Anthropocene, with intricate relationships made more difficult in the face of climate change, integrated research in socio-ecological systems may provide a comprehensive approach to better evaluate and understand our changing world.

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 124-131). / xv, 131 leaves, bound ill. (some col.) 29 cm