Land cover dynamics and climate change implications on water resources in South Pacific Costa Rica

Water is fundamental to human life and the availability of freshwater is often a constraint on human welfare and economic development. Consequently, the potential effects of global changes on hydrology and water resources are considered among the most severe and vital ones. Water scarcity is one of the main problems in the rural communities of Central America, as a result of an important degradation of catchment areas and the over-exploitation of aquifers. The present Thesis is focused on two critical aspects of global changes over water resources: (1) the potential effects of climate change on water quantity and (2) the impacts of land cover and land use changes on the hydrological processes and water cycle. Costa Rica is among the few developing countries that have recently achieved a land use transition with a net increase in forest cover. Osa Region in South Pacific Costa Rica is an appealing study site to assess water supply management plans and to measure the effects of deforestation, forest transitions and climate change projections reported in the region. Rural Community Water Supply systems (ASADAS) in Osa are dealing with an increasing demand of freshwater due to the growing population and the change in the way of life in the rural livelihoods. Land cover mosaics which have resulted from the above mentioned processes are characterized by the abandonment of marginal farmland with the spread over these former grasslands of high return crops and the expansion of secondary forests due to reforestation initiatives. These land use changes have a significant impact on runoff generation in priority water-supply catchments in the humid tropics, as evidenced by the analysis of the Tinoco Experimental Catchment in the Southern Pacific area of Costa Rica. The monitoring system assesses the effects of the different land uses on the runoff responses and on the general water cycle of the basin. Runoff responses at plot scale are analyzed for secondary forests, oil palm plantations, forest plantations and grasslands. The Oil palm plantation plot presented the highest runoff coefficient (mean RC=32.6%), twice that measured under grasslands (mean RC=15.3%) and 20-fold greater than in secondary forest (mean RC=1.7%). A Thornthwaite-type water balance is proposed to assess the impact of land cover and climate change scenarios over water availability for rural communities in Osa Region. Climate change projections were obtained by the downscaling of BCM2, CNCM3 and ECHAM5 models. Precipitation and temperature were averaged and conveyed by the A1B, A2 and B1 IPCC climate scenario for 2030, 2060 and 2080. Precipitation simulations exhibit a positive increase during the dry season for the three scenarios and a decrease during the rainy season, with the highest magnitude (up to 25%) by the end of the 21st century under scenario B1. Monthly mean temperature simulations increase for the three scenarios throughout the year with a maximum increase during the dry season of 5% under A1B and A2 scenarios and 4% under B1 scenario. The Thornthwaite-type Water Balance model indicates important decreases of water surplus for the three climate scenarios during the rainy season, with a maximum decrease on May, which under A1B scenario drop up to 20%, under A2 up to 40% and under B1 scenario drop up to almost 60%. Land cover scenarios were created taking into account current land cover dynamics of the region. Land cover scenario 1 projects a deforestation situation, with forests decreasing up to 15% due to urbanization of the upper catchment areas; land cover scenario 2 projects a forest recovery situation where forested areas increase due to grassland abandonment on areas with more than 30% of slope. Deforestation scenario projects an annual water surplus decrease of 15% while the reforestation scenario projects a water surplus increase of almost 25%. This water balance analysis indicates that climate scenarios are equal contributors as land cover scenarios to future water resource estimations.

Eolian and silica deposition of ODP sites in the central North Pacific

Sediments recovered at Ocean Drilling Program Sites 885/886 (central North Pacific Ocean at 44°41'N, 168°14'W and 44°41'N, 168°16'W, respectively) record eolian deposition during the Cenozoic and late Mesozoic. We constructed a record of eolian MAR, which is a proxy for aridity/humidity of the climate in the continental source area. Eolian fluxes are low during the Late Cretaceous through Eocene, reflecting humid conditions in the source area. During the Oligocene, more arid climates prevailed at the source area, as indicated by increased eolian accumulation. The "Diatom Dump", an interval of enhanced silica deposition mainly apparent in the northwest Pacific, is reflected in the record at Sites 885/886 by two- to fivefold higher opal fluxes compared with younger and older sediments. Increased eolian deposition starting at 3.5 Ma and culminating at 2-2.6 Ma are coincident with the onset of Northern Hemisphere glaciation. Sites 885/886 lie 10° north of sites examined previously for the history of eolian deposition in the central North Pacific and therefore allow enhanced understanding of the latitudinal variation of the wind system.

Abyssal community analysis from replicate box cores in the central North Pacific

A 0.25 m**2 United States Naval Electronics Laboratory box corer was used to take replicate samples from an oligotrophic bottom under the North Pacific Central Water Mass (~28°N, 155°W). The bottom is a red clay with manganese nodules at a depth of 5500-5800 m. Macrofaunal density ranges from 84 to 160 individuals per m**2 and is therefore much the same as in Northwest Atlantic Gyre waters. Of the macrofaunal taxa, polychaetes dominate (55 %), followed by tanaids (18 %), bivalves (7 %), and isopods (6 %). Meiofaunal taxa were only partially retained by the 297 µm screen used in washing. Even then, they are 1.5-3.9 times as abundant as the macrofaunal taxa, with nematodes being numerically dominant by far. Foraminifera seem to comprise an important portion of the community, but could not be assessed accurately because of the inability to discriminate living and dead tests. Remains of what are probably xenophyophoridans are also very important, but offer the same problem. Faunal diversity is extremely high, with deposit feeders comprising the overwhelming majority. Most species are rare, being encountered only once. The distributions of only three species show any significant deviation from randomness. The polychaete fauna from box cores collected from 90 miles to the north was not significantly different from that of the principal study locality. Concordance appeared at several taxonomic levels, from species through macrofaunal/meiofaunal relationships. As a result, the variation in total animal abundance shows aggregation among cores. We discuss Sokolova's concept of a deep-sea oligotrophic zone dominated by suspension feeders, and reconcile it with our present findings. The high diversity of the fauna combined with the low food level contradict theories that relate diversity directly with productivity.

Late Eocene to Recent deep-sea benthic foraminifera from the Central equatorial Pacific Ocean

Benthic foraminifers were studied in upper Eocene to Recent core-catcher samples from DSDP Sites 573, 574, and 575. The sites are on a north-south transect from the equator to about 05°N at about 133°W, water depth 4300 to 4600 m. At Site 574 additional samples were used to study the Eocene/Oligocene boundary in detail. About 200 specimens were counted per sample. The fauna is highly diverse (about 50 to 70 species per sample) and is of low dominance. The diversity is not related to age or sub-bottom depth. Many species are cosmopolitan and probably have wide environmental tolerances. Fluctuations in frequency of some taxa (e.g., Nuttallides umbonifera, Epistominella exigua, and Uvigerina spp.) cannot be correlated from one site to another. Several common species (e.g. Oridorsalis umbonatus and Globocassidulina subglobosa) range from late Eocene to Recent. First and last appearances are generally difficult to define precisely because many species are rare. For some species these datums differ from one site to another, but several datum levels are within 1 m.y. at all sites. First and last appearances are most numerous in two intervals, the late Eocene to early Oligocene (about 32 to 37 Ma) and the early to middle Miocene (about 13 to 18.5 Ma). Isotopic events occur within each of these periods of benthic faunal change, but the isotopic events have a shorter duration and start after the initiation of the changes in the fauna. Changes in deep-sea benthic faunal composition are not directly related to short-term oceanographic changes as expressed in isotopic records.

Relative abundance of planktonic foraminifera in Pliocene and Pleistocene sediments of DSDP Hole 32-310 from Hess Rise, Central North Pacific (Table II)

Late Neogene planktonic foraminifera have been examined at Site 310 in the Central North Pacific and their stratigraphic ranges and frequencies are presented here. Blow's (1969) zonation developed for tropical regions has been applied where applicable. Where tropical index taxa are rare or absent in this temperate region, Globorotalia crassaformis, and the evolutionary bioseries G. conoidea - G. conomiozea and G. puncticulata - G. inflata have been found useful for zonal subdivisions. A correlation between stratigraphic ranges and frequency distributions of these species at Site 310 in the Central North Pacific, and Site 284 in the Southwest Pacific indicates that these species are relatively consistent biostratigraphic markers in temperate regions of both the North and South Pacific Oceans. An informal zonation for temperate latitudes of the Southwest Pacific has been established by Kennett (1973) and a similar zonal subdivision can be made at Site 310. Paleoclimatic/paleoceanographic interpretations based on coiling ratios, percent abundance, and phenotypic variations of Neogloboquadrina pachyderma indicate four major cold events during early, middle, and late Pliocene, and early Pleistocene. Faunal correlations of these events with similar events elsewhere in the Northeast and Southwest Pacific which have been paleomagnetically dated indicate the following approximate ages for these cold events: 4.7 Ma, 3.0 Ma, 2.6-1.8 Ma, and 1.2 Ma. Faunal assemblages have been divided into three groups representing cool, intermediate, and warmer water assemblages. Cool water assemblages are dominated by ~60% N. pachyderma; intermediate temperature faunas are dominated by species of Globigerina and Globigerinita and contain between 20% and 30% N. pachyderma. Warmer water assemblages are dominated by species of Globorotalia and contain <10% N. pachyderma. Frequency oscillations within these groups, in addition to paleotemperature parameters evident in N. pachyderma, afford refined paleoclimatic/paleoceanographic interpretations.

Nutrients of pore water in sediments of the central equatorial Pacific

Shipboard whole-core squeezing was used to measure pore water concentration vs depth profiles of [NO3]-, O2 and SiO2 at 12 stations in the equatorial Pacific along a transect from 15°S to 11°N at 135°W. The [NO3]- and SiO2 profiles were combined with fine-scale resistivity and porosity measurements to calculate benthic fluxes. After using O2 profiles, coupled with the [NO3]- profiles, to constrain the C:N of the degrading organic matter, the [NO3]- fluxes were converted to benthic organic carbon degradation rates. The range in benthic organic carbon degradation rates is 7-30 ?mol cm**-2 y**-1, with maximum values at the equator and minimum values at the southern end of the transect. The zonal trend of benthic degradation rates, with its equatorial maximum and with elevated values skewed to the north of the equator, is similar to the pattern of primary production observed in the region. Benthic organic carbon degradation is 1-2% of primary production. The range of benthic biogenic silica dissolution rates is 6.9-20 µmol cm**-2 y**-1, representing 2.5-5% of silicon fixation in the surface ocean of the region. Its zonal pattern is distinctly different from that of organic carbon degradation: the range in the ratio of silica dissolution to carbon degradation along the transect is 0.44-1.7 mol Si mol C**-1, with maximum values occurring between 12°S and 2°S, and with fairly constant values of 0.5-0.7 north of the equator. A box model calculation of the average lifetime of the organic carbon in the upper 1 cm of the sediments, where 80 +/- 11% of benthic organic carbon degradation occurs, indicates that it is short: from 3.1 years at high flux stations to 11 years at low flux stations. The reactive component of the organic matter must have a shorter lifetime than this average value. In contrast, the average lifetime of biogenic silica in the upper centimeter of these sediments is 55 +/- 28 years, and shows no systematic variations with benthic flux.

Annotated record of the detailed examination of Mn deposits from the CLIMAX II (SCAN) Expedition stations aboard R/V Argo in the central North Pacific

A 0.25 m US Naval Electronics Lab box corer was used to take replicate samples from an oligotrophic bottom under the North Pacific Central Water Mass (approx. 28 degrees N, 155 degrees W). The bottom is a red clay with manganese nodules at a depth of 5500-5800 m. Macrofaunal density ranges from 84 to 160 individuals per m super(2) and is therefore much the same as in Northwest Atlantic Gyre waters. Of the macrofaunal taxa, polychaetes dominate (55 per cent), followed by tanaids (18 per cent), bivalves (7 per cent), and isopods (6 per cent). Meiofaunal taxa were only partially retained by the 297 micrometer screen used in washing. Even then, they are 1.5-3.9 times as abundant as the microfaunal taxa, with nematodes being numerically dominant by far. Foraminifera seem to comprise an important portion of the community, but could not be assessed accurately because of the inability to discriminate living and dead tests. Remains of what are probably xenophyophoridans are also very important, but offer the same problem. Faunal diversity is extremely high, with deposit feeders comprising the overwhelming majority. Most spp are rare, being encountered only once. The distributions of only 3 spp show any significant deviation from randomness. The polychaete fauna from box cores collected from 90 m to the north was not significantly different from that of the principal study locality. Concordance appeared at several taxonomic levels, from spp through microfaunal/ meiofaunal relationships. As a result, the variation in total animal abundance shows aggregation among cores. The authors discuss Sokolova's concept of a deep-sea oligotrophic zone dominated by suspension feeders, and reconcile it with our present findings. The high diversity of the fauna combined with the low food level contradict theories that relate diversity directly with productivity.

Long-term biogenic particle fluxes in the Bering Sea and the central subarctic Pacific Ocean

Time-series sediment traps were deployed for five consecutive years in two distinctively different subarctic marine environments. The centrally located subarctic pelagic Station SA (49°N, 174°W; water depth 5406 m) was simultaneously studied along with the marginal sea Station AB (53.5°N, 177°W; water depth 3788 m) in the Aleutian Basin of the Bering Sea. A mooring system was tethered to the sea-floor with a PARFLUX type trap with 13 sample bottles, which was placed at 600 m above the sea-floor at each of the two stations. Sampling intervals were synchronized at the stations, and they were generally set for 20 days during highly productive seasons, spring through fall, and 56 days during winter months of low productivity. Total mass fluxes, which consisted of mainly biogenic phases, were significantly greater at the marginal sea Station AB than at the pelagic Station SA for the first four years and moderately greater for the last year of the observations. This reflects the generally recognized higher productivity in the Bering Sea. Temporal excursion patterns of the mass fluxes at the two stations generally were in parallel, implying that temporal changes in their biological productivity are strongly governed by a large-scale seasonal climatic variability over the region rather than local phenomena. The primary reason for the difference in total mass flux at the two stations stems mainly from varying contributions of siliceous and calcareous planktonic assemblages. A significantly higher opal contribution at Station AB than at Station SA was mainly due to diatoms. Diatom fluxes at the marginal sea station were about twice those observed at the pelagic station, resulting in a very high opal contribution at Station AB. In contrast to the opal fluxes, CaCO3 fluxes at Station AB were slightly lower than at Station SA. The ratios of Corg/Cinorg were usually significantly greater than one in both regions, suggesting that preferentially greater organic carbon from cytoplasm than skeletal inorganic carbon was exported from the surface layers. Such a process, known as the biological pump, leads to a carbon sink which effectively lowers p CO2 in the surface layers and then allows a net flux of atmospheric CO2 into the surface layer. The efficiency of the biological pump is greater in the Bering Sea than at the open-ocean station.

Taxonomy and diagnostics of fruit fly infesting Opiine Braconids in Australia and the South Pacific

Opiine wasps (Hymenoptera: Braconidae: Opiinae) are parasitoids of dacine fruit flies (Diptera: Tephritidae: Dacinae), the primary horticultural pests of Australia and the South Pacific. Effective use of opiines for biological control of fruit flies is limited by poor taxonomy and identification difficulties. To overcome these problems, this thesis had two aims: (i) to carry out traditional taxonomic research on the fruit fly infesting opine braconids of Australia and the South Pacific; and (ii) to transfer the results of the taxonomic research into user friendly diagnostic tools. Curated wasp material was borrowed from all major Australian museum collections holding specimens. This was supplemented by a large body of material gathered as part of a major fruit fly project in Papua New Guinea: nearly 4000 specimens were examined and identified. Each wasp species was illustrated using traditional scientific drawings, full colour photomicroscopy and scanning electron microscopy. An electronic identification key was developed using Lucid software and diagnostic images were loaded on the web-based Pest and Diseases Image Library (PaDIL). A taxonomic synopsis and distribution and host records for each of the 15 species of dacine-parasitising opiine braconids found in the South Pacific is presented. Biosteres illusorius Fischer (1971) was formally transferred to the genus Fopius and a new species, Fopius ferrari Carmichael and Wharton (2005), was described. Other species dealt with were Diachasmimorpha hageni (Fullaway, 1952), D. kraussii (Fullaway, 1951), D. longicaudata (Ashmead, 1905), D. tryoni (Cameron, 1911), Fopius arisanus (Sonan, 1932), F. deeralensis (Fullaway, 1950), F. schlingeri Wharton (1999), Opius froggatti Fullaway (195), Psyttalia fijiensis (Fullaway, 1936), P. muesebecki (Fischer, 1963), P. novaguineensis (Szépliget, 1900i) and Utetes perkinsi (Fullaway, 1950). This taxonomic component of the thesis has been formally published in the scientific literature. An interactive diagnostics package (“OpiineID”) was developed, the centre of which is a Lucid based multi-access key. Because the diagnostics package is computer based, without the space limitations of the journal publication, there is no pictorial limit in OpiineID and so it is comprehensively illustrated with SEM photographs, full colour photographs, line drawings and fully rendered illustrations. The identification key is only one small component of OpiineID and the key is supported by fact sheets with morphological descriptions, host associations, geographical information and images. Each species contained within the OpiineID package has also been uploaded onto the PaDIL website (www.padil.gov.au). Because the identification of fruit fly parasitoids is largely of concern to fruit fly workers, rather than braconid specialists, this thesis deals directly with an area of growing importance to many areas of pure and applied biology; the nexus between taxonomy and diagnostics. The Discussion chapter focuses on this area, particularly the opportunities offered by new communication and information tools as new ways delivering the outputs of taxonomic science.

Sourcing and evaluating IT business value in emerging economies : the case of the South Pacific Island Countries

Information Technology (IT) is an important resource that facilitates growth and development in both the developed and emerging economies. The increasing forces of globalization are creating a wider digital divide between the developed and emerging economies. The smaller emerging economies are the most venerable. Intense competition for IT resources means that these emerging economies would need to acquire a deeper understanding of how to source and evaluate their IT-related efforts. This effort would put these economies in a better position to source funding from various stakeholders. This research presents a complementary approach to securing better IT-related business value in organizations in the South Pacific Island countries – a case of emerging economies. Analysis of data collected from six South Pacific Island countries suggests that organizations that invest in IT and related complementaries are able to better their business processes. The data also suggest that improved business processes lead to overall business processes improvements.

Recent emergence of dengue virus serotype 4 in French Polynesia results from multiple introductions from other south pacific islands

BACKGROUND: Infection by dengue virus (DENV) is a major public health concern in hundreds of tropical and subtropical countries. French Polynesia (FP) regularly experiences epidemics that initiate, or are consecutive to, DENV circulation in other South Pacific Island Countries (SPICs). In January 2009, after a decade of serotype 1 (DENV-1) circulation, the first cases of DENV-4 infection were reported in FP. Two months later a new epidemic emerged, occurring about 20 years after the previous circulation of DENV-4 in FP. In this study, we investigated the epidemiological and molecular characteristics of the introduction, spread and genetic microevolution of DENV-4 in FP. METHODOLOGY/PRINCIPAL FINDINGS: Epidemiological data suggested that recent transmission of DENV-4 in FP started in the Leeward Islands and this serotype quickly displaced DENV-1 throughout FP. Phylogenetic analyses of the nucleotide sequences of the envelope (E) gene of 64 DENV-4 strains collected in FP in the 1980s and in 2009-2010, and some additional strains from other SPICs showed that DENV-4 strains from the SPICs were distributed into genotypes IIa and IIb. Recent FP strains were distributed into two clusters, each comprising viruses from other but distinct SPICs, suggesting that emergence of DENV-4 in FP in 2009 resulted from multiple introductions. Otherwise, we observed that almost all strains collected in the SPICs in the 1980s exhibit an amino acid (aa) substitution V287I within domain I of the E protein, and all recent South Pacific strains exhibit a T365I substitution within domain III. CONCLUSIONS/SIGNIFICANCE: This study confirmed the cyclic re-emergence and displacement of DENV serotypes in FP. Otherwise, our results showed that specific aa substitutions on the E protein were present on all DENV-4 strains circulating in SPICs. These substitutions probably acquired and subsequently conserved could reflect a founder effect to be associated with epidemiological, geographical, eco-biological and social specificities in SPICs.

On facilitating regional integration and economic development with collaborative technologies in the South Pacific

The current global economic instability and the vulnerability of small island nations are providing the impetus for greater integration between the countries of the South Pacific region. This exercise is critical for their survival in today’s turbulent economic environment. Past efforts of regional integration in the South Pacific have not been very successful. Reasons attributed to this outcome include issues related to damage of sovereignty, and lack of a shared integration infrastructure. Today, the IT resources with collaborative capacities provide the opportunity to develop a shared IT infrastructure to facilitate integration in the South Pacific. In an attempt to develop a model of regional integration with an IT-backed infrastructure, we identify and report on the antecedents of the current stage of regional integration, and the stakeholders’ perceived benefits of an IT resources backed regional integration in the South Pacific. Employing a case study based approach, the study finds that while most stakeholders were positive about the potential of IT-backed regional integration, significant challenges exist that hinder the realisation of this model. The study finds that facilitating IT-backed regional integration requires enabling IT infrastructure, equitable IT development in the region, greater awareness on the potential of the modern IT resources, market liberalisation of the information and telecommunications sector and greater political support for IT initiatives.