Cadmium in the ocean has a nutrient-like cycling pattern: with biological uptake at the surface, subsequent sinking in particulate form and then regeneration as dissolved species in deeper waters. Many measurements have been made over time of the ratio of the concentrations of dissolved Cd to those of PO₄ (Cd/PO₄) in the world ocean and this has become one of the best relationships documented between a trace metal and a nutrient. Combined with the measurements of the Cd/Ca ratio in foraminifera, the Cd/PO₄ ratio has been used to reconstruct the oceanographic circulation patterns that existed during past glacial periods and hence provides information on past climate changes. In the present study Cd/PO₄ ratios of the Southern Indian Ocean in surface and deep waters were investigated. The slopes of the relationships between Cd and PO₄ concentrations in waters of this region are high compared to the global correlations, and lie between those reported for other parts of the Southern Ocean and the Pacific Ocean. In surface waters of the Southern Indian Ocean, Cd/PO₄ ratios decrease from regions exhibiting high nutrient-low chlorophyll (HNLC) characteristic in the south to oligotrophic waters further north. It is also found that particulate Cd plays an important role in regulating the high Cd/PO₄ ratios reported in waters south of the Polar Front. Very low Cd/PO₄ ratios were measured in waters associated with the Subtropical Front southeast of New Zealand compared to other Southern Ocean and global oceanic waters. Seasonal variations in the Cd/PO₄ ratios measured for these waters strongly suggest they are associated with a significant biological uptake of dissolved Cd particularly during the phytoplankton growth season in summer. Dissolved Fe concentrations in the Southern Indian Ocean and seasonal variations of Fe in waters off the Otago Coast (southeast of New Zealand) suggest that Fe may stimulate phytoplankton growth and this might result in lower Cd/PO₄ ratios in surface waters through enhanced Cd uptake relative to PO₄ by the phytoplankton. However there is no distinct relationship between dissolved Fe concentrations and the dissolved Cd/PO₄ ratios measured in these surface waters. This finding is in disagreement with the recent 2006 hypothesis put forward by J.T. Cullen, which proposed that waters exhibiting low dissolved Cd/PO₄ ratios were associated with the HNLC regions. From a consideration of the potential Zn concentrations calculated from Si concentration measurements reported for these waters, it would appear that Zn may play a more important role than Fe in regulating Cd/PO₄ ratios in these waters. Measurements of dissolved and total Cd concentrations relative to those of PO₄ were also undertaken in the Otago Harbour and immediate surrounding coastal waters. These exhibited higher Cd concentrations and higher Cd/PO₄ ratios than open ocean waters further off the Otago Coast. The particulate Cd concentrations showed a negative correlation with Cd concentrations measured in cockle species (Austrovenus stuchburyi) collected in the harbour, suggesting that particulate Cd is not the source of Cd measured in the tissue of this species. The concentrations of Cd and other trace metals were also measured in samples of green mussel (Perna canaliculus), ribbed mussel (Aulacomya atra maoriana) and oyster (Saccostrea cucullata) collected from Otago Harbour and possible correlations explored between these concentrations and other parameters such as the shellfish condition indices and environmental gradients in the harbour. In summary, measurements of dissolved and particulate Cd concentrations in the water column can provide unique information on a number of processes occurring in the global marine environment.

Abstract In Taiwan, long-line fishing has been the major technique in fishery. With the enhancement of fishing techniques, the fishing zone of Taiwan has spread all over three of World Oceans, and Taiwan has been regarded as one of five largest pelagic fishing countries. Pelagic long-line fishery plays a crucial role in economic development in Taiwan. In recent years, the fishery environments, whether in domestic or foreign fishing zone, have been dramatically changing. Since the United Nations Convention on the Law of the Sea has been resulted, all of coastal nations have subsequently set up the Exclusive Economic Zone (EEZ) or marine economic development zone, which is stretched out 200 nautical miles from a nation¡¦s coast. However, the establishment of marine economic development zone also brings about the high seas¡¦ largely shrinking. Since the past, the increasing extinction of fish species is mainly resulted from illegal fishing techniques, fishing in the fishing-prohibited zone or during the prohibited period, catching fingerlings and using illegitimate fishing gear. Under such a decreasing fishing circumstance, those Taiwanese long-line fishing vessels under 100 tonnes, mostly fishing in the South Pacific Ocean, are struggling with many changes, such as international fishing limitation, the fishing vessels decreasing policy, the diminishing amount of fish caused by climate changes, the raising oil price and cost. Respecting the situation that most of long-line fishing vessels are managed by ship owners instead of fishery companies, and the fishing-related records are too scarce to provide for reference, this research will explore how the 100-tonne-under long-line fishing vessels owners can manage their business in South Pacific Ocean. All information in this study is acquired from Fisheries Agency in Taiwan and interviews with long-line fishing vessels owners. The questions asked in those interviews mainly target fishing benefit, cost, method of supplies, and the policy on captain and crew management. Based on the analysis of those cases mentioned above, we can figure out the practical operation and management of the 100-tonne-under long-line fishing vessels owners in Taiwan. Furthermore, this study also points out current difficulties in fishery management, providing for those vessels owners as the crucial reference of increasing competitive advantages. Keywords: Long-Line Fishing, South Pacific Ocean, Business Management, Yellowfin Tuna, Cost-Benefit Analysis

Abstract This study used the Gordon-Schaefer model to do resource economic analysis on the South Pacific albacore fishery in 1967-2007 . Evaluated the equilibrium standard of open access model and present value maximization model, and then compared them with the real data. The results indicates that the fishing yield, resource stock, effort and catch-per-unit-effort of south Pacific albacore is close to the equilibrium level of present value maximization model after year 2002, which means the South Pacific albacore fishing is under appropriate development. Following that, this paper did sensitivity analysis to understand the impact of the changed parameters on stock size and effort. Finally, using the simulation analysis on open access model and present value maximization model. In open access model, the result shows that resources will face extinction crisis if the fishery is not controlled well. In present value maximization model, the albacore fishery would sustainable management. This result is valuable for the fishery management authorities to maintain the development of fishery and cherishing ocean resources at the same time.

Ocean nitrogen fixation and denitrification are crucial nitrogen source and sink mechanisms for the global ocean environment. While recent studies have reported that oceanic denitrification has increased over the last few decades, others have suggested that global ocean nitrogen fixation rates have been underestimated, and still others that anthropogenic perturbations have altered the global nitrogen cycle. This implies that the current estimates of the oceanic nitrogen inventory are incomplete and they need to be revised with more information. In addition, current denitrification estimates need to be reexamined due to their large associated uncertainties. Thus, I have conducted research estimating denitrification rates in three different locations: the northern Gulf of Mexico (GOM), the East/Japan Sea (EJS), and the South Pacific: from coastal to marginal to open ocean scale in different oceanographic conditions. Denitrification rates in the bottom layer (including bottom waters+sediments) at the shallow and often hypoxic northern GOM ranged from 103-544 [mu]mol N m⁻² d⁻¹ (=1.4 to 7.4 Gg N mon⁻¹ with area=3.24x10¹⁰m²), and were controlled not only by biogeochemical factors (i.e. organic matter supply and remineralization), but also by physical factors (i.e. stratification and relative contributions from different water masses). Despite high dissolved oxygen concentrations, the significant decrease in nitrate concentrations below the expected levels, low N/P ratio (<12.4), and deep nitrite peak in the bottom layer indicate a presence of denitrification in EJS, confined at the Tatar Strait and the Ulleung Basin areas. The estimated denitrification rates range from 0.3 to 33.2 [mu]mol N m⁻² d⁻¹, and was comparable to the directly measured denitrification rates from sediment samples. The high-quality repeat hydrographic datasets observed at 32°S of the South Pacific Ocean offer an opportunity to estimate water column denitrification rates on a basin-scale in the open ocean away from the Eastern Tropical Pacific oxygen minimum zones. The mean water column denitrification rates in the oxygen minimum layer of P06 line (32°S) were estimated to range between 7.1 and 18.5 [mu]mol N m⁻² d⁻¹. The results imply that, although very small at any particular site, once integrated over a basin-scale, the open ocean water column denitrification can be a significant component of the oceanic nitrogen budget. Denitrification is subject to seasonal, decadal and possibly climate scale variations. While it is commonly estimated at the oxygen minimum zones or sediments, denitrification is not merely confined to such regions only, and small amounts of denitrification occur in other oceanic parts. Once integrated, it may be quantitatively significant for the world's oceans. Denitrification is playing a significant role in local, regional, and global ocean scales. In the future, we need to consider variability of denitrification in coastal regions, and to investigate denitrification in unexpected and unexplored regions, in order to improve our knowledge on global oceanic mass balance. / text

The El Niño-Southern Oscillation (ENSO) dominates global interannual climate variability. However, the imprint of anthropogenic climate change hinders understanding of natural ENSO variability. Model predictions of the response of future ENSO variability to anthropogenic forcing are highly uncertain. A better understanding of how ENSO operates during different mean climate states may improve predictions of its future behavior. This study develops a technique to quantify the response of tropical Pacific sea surface temperature and salinity to ENSO variations. This analysis defines expected regional relationships between ENSO forcing and the tropical Pacific climate response. For example, the western tropical Pacific records El Niño events with greater skill than La Niña events; whereas the oceans near the South Pacific Convergence Zone (SPCZ) preferentially record La Niña events. This baseline understanding of regional skill calibrates interpretations of both modern and pre-instrumental coral geochemical climate proxy records. A suite of monthly resolved 18O variations in a fossil corals (Porites spp.) from the tropical western Pacific (Papua New Guinea) and the SPCZ (Vanuatu) are used to develop case studies of ENSO variability under external forcing conditions that differ from the modern climate. A record from Misima, Papua New Guinea (1411-1644 CE) spans a period of reduced solar forcing that coincides with the initiation of the Little Ice Age. This record indicates that the surface ocean in this region experienced a small change in hydrologic balance with no change in temperature, extended periods of quiescence in El Niño activity, reduced mean El Niño event amplitudes, and fewer large amplitude El Niño events relative to signals captured in regional modern records. Several multidecadal (~30-50 year) coral records from Tasmaloum, Vanuatu during the Medieval Climate Anomaly (~900-1300 CE), a period of increased solar forcing, depict ENSO variability that is generally lower than modern times. However, these records often cannot be distinguished from 20th century ENSO variability due to ENSO variability uncertainty associated with record lengths. Neither record can be tied to concurrent changes in solar or volcanic forcing, calling into question the paradigm of ENSO variability being predominantly mediated by external forcing changes on multidecadal time scales. / text

The oral histories utilized by this research reveal the experiences of those who suffered leprosy in five South Pacific nations, Fiji, New Caledonia, Samoa, Tonga and Vanuatu. This thesis explores how leprosy and its stigma impacted on the lives of these people, some of whom suffered decades of isolation at various leprosaria including the case of one New Caledonian resident for nearly seventy years. The testimonies of their experiences of diagnosis, removal into isolation, medical treatment and eventual discharge back to their homes implicitly contain descriptions of attitudes of stigma in their communities. This research reveals that where there is openness and knowledge about the minimal risk of leprosy contagion, as occurred in Fiji and Vanuatu from the 1950s, less stigma is attached to the disease. Nevertheless even in these countries, prior to the 1950s and availability of any effective medication, the fear and horror of the physical effects of leprosy was such that the victims were either cast out or chose to move away from their homes. This segregation led to groups of leprosy sufferers banding together to help care for each other. Once the policy of isolation in leprosaria was implemented, advanced cases of leprosy benefited from the better medical facilities and found opportunities for friendships and camaraderie. However, where the conditions at leprosaria were miserable and movements of the residents visibly restricted by fences, as occurred in Samoa and Tonga, there was heightened leprosy stigma. Perceptions of stigma varied from person to person and region to region. Higher levels of stigma were evident in New Caledonia, where leprosaria had been situated at former prison sites and strict isolation enforced, and in Tonga, where the removal of all leprosy sufferers had from the earliest days been associated with biblical strictures asserting that leprosy was a curse and the sufferers unclean. Following the availability of sulphone treatment in the South Pacific in the1950s and the improved medication in the 1980s, leprosy need no longer be physically disfiguring or disabling. Assisted by the generous donations gathered by the Pacific Leprosy Foundation in New Zealand to the medical services at the central leprosy hospital in Fiji, and by direct assistance to leprosy sufferers in the Pacific, the disadvantages that were imposed by leprosy in the past are disappearing and as one contributor to the project said ‘the time of darkness’ is ending.

The islands of the tropical South Pacific (TSP) are considered biodiversity hotspots. However, the biota of this region has received limited scientific attention and very little is known about its diversity, ecology and evolution. In this thesis we investigate some of the ecological and evolutionary processes in the TSP, focussing on lowland rain forests. We use molecular techniques to investigate evolutionary processes and vegetation surveys to study species diversity patterns and ecological processes. Chapter 1 reviews molecular, distributional and geographic evidence for dispersal versus vicariance explanations for the diversity and distribution of the TSP biota. Most islands of the TSP are geologically young (less than 40 million years old) and of oceanic origin, so most (if not all) of the biota on islands in the TSP arrived through long-distance dispersal events. This view is strongly corroborated by genetic data from published studies. Molecular studies also suggest two major source areas. One is located in the northwest, which includes Malesia and Southeast Asia, while the other is in the southwest and includes New Caledonia, Australia and New Zealand. We argue that local extinctions have occurred in source and stepping stone areas, creating sources of error for the interpretation of distribution and molecular data. In Chapter 2 we use allozyme data to investigate the question how Pacific cycads (Cycas, subsection Rumphiae) colonised the Pacific. We show that they colonised the Pacific and East Africa by long-distance dispersal, probably through floating seeds from a Malesian source area. Allozymes and morphological data provide support for two major groups within subsection Rumphiae and reveal close relationships between the extant species, suggesting very recent and/or ongoing dispersal events. Cycads are an example of recent diversification in a lineage with a long fossil record. The podocarp genus Dacrydium is another lineage with a long fossil record and in chapter 3 we investigate the colonisation and speciation processes in this lineage using allozymes and trnL-trnF plastid sequences. Our results suggest that the Pacific species of Dacrydium arrived recently (within the last 10 million years) in the TSP but are inconclusive about the source area of the genus. Combined molecular and ecological data suggest the occurrence of both allopatric and sympatric speciation in the Pacific radiation in this genus. Allozyme data also demonstrate the occurrence of hybridisation between two New Caledonian species. Our findings suggest that hybridisation and sympatric speciation may have played an important role in the evolution of the biota in the TSP. In chapter 4 we attempt to untangle the disparate forces driving alpha species diversity, forest structure and species composition in old-growth lowland tropical rainforest by assessing the tree species composition of twelve 1 ha vegetation count plots on 13 islands between New Guinea and Samoa. Using simplifications of a model based on biogeographic and ecological disturbance theory, we show that species diversity and richness are mainly influenced by size and area of an island, while endemism is mostly determined by isolation and area. High cyclone frequency is shown to increase the density of stems (with dbh > 10 cm). Correlations between the abundance of widespread canopy tree taxa and cyclone frequency suggest that cyclones affect species composition by increasing the abundance of cyclone-resistant species. However, floristic similarities show that geographic distance also affects species composition. It therefore appears that, for lowland rain forests in the TSP, biogeography is the major driver of species diversity and endemism and that disturbance is the major driver of forest structure, while both biogeography and disturbance affect the species composition. In chapter 5 we test the ability of NDVI (Normalised Difference Vegetation Index, a remotely sensed index of productivity) data and leaf samples as covariates of alpha species diversity using twelve vegetation count plots. NDVI performed poorly in estimating species diversity and species richness. However, the cost- and time-efficiency associated with remotely sensed data shows the potential of these methods, but only if accurate methods to estimate species richness are found. Species richness and species diversity estimates obtained from leaf litter samples correlate reasonably well with similar estimates obtained from count plots and are more than 30% cheaper and about 10% faster to obtain. If travel can be avoided through collaboration, leaf litter-based estimates of diversity could be obtained at about 5% the cost and in about half the time compared to count plots. Therefore the analysis of leaf litter is potentially a suitable and efficient method to obtain rapid estimates of species diversity in count plots. The final chapter discusses the roles of ecological and evolutionary processes in the TSP. While research to date has been scarce, especially on ecological processes acting on large scales, data show that the effects of ecology, evolution and biogeography are interlinked during the colonisation, establishment and subsequent evolution of taxa and biomes in the TSP.

Pelagic clays cover nearly one half of the ocean floor, but are rarely used for paleoceanographic research because of their extremely slow sedimentation rates, post-depositional alteration(s), and the lack of biogenic material available to provide ages. My dissertation develops and applies approaches to study pelagic clays by targeting the largest marine sediment province in the world: the South Pacific Gyre (SPG). I present an unprecedented spatially and temporally extensive paleoceanographic history of the SPG and discuss authigenic processes in pelagic clays that are linked to changes in global seawater composition through the Cenozoic. My research was based on an extensive inorganic geochemical dataset I developed from samples gathered during Integrated Ocean Drilling Program Expedition 329. I applied multivariate statistical techniques (e.g., Q-mode factor analysis and constrained least squares multiple linear regression (CLS)) to the dataset in order to (a) identify the existence of six end-members in pelagic clay (namely, eolian dust, Fe/Mn-oxyhydroxides, apatite, excess Si, and two types of volcanic ash), (b) quantify their abundances, (c) determine their mass accumulation rates, and (d) infer major features in the paleoceanographic evolution of the SPG. Key parts of my research also developed improved MATLAB codes to facilitate and speed the search for best fitting end-member combinations in CLS modeling. Additionally, I expanded the natural gamma radiation instrumental capabilities on the D/V JOIDES Resolution to quantify concentrations of uranium, thorium, and potassium. I dated the pelagic clay at four of the IODP sites with a cobalt-based age model that I developed, and documented that the seawater behavior of cobalt determines the extent to which this method can be applied. Collectively, the results track the spatial extent of dust deposition in the SPG during the aridification of Australia, dispersed ash accumulation from episodes of Southern Hemisphere volcanism, and other features of Earth’s evolution during the Cenozoic. I further quantified two geochemically distinct types of authigenic ash alterations within the pelagic clay, indicating that altered ashes may be a significant and variable sink of magnesium in seawater over geologic timescales.

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