The genus Neomonoceratina(Crustacea: Ostracoda) from the Cainozoic of the West Pacific margins

Fourteen species of Neomonoceratina from the West Pacific margins are considered in the present paper, of which two species and one subspecies are described as new. Lectotypes have been designated for three of Brady's 1868 species (N. bataviana, N. iniqua and N. rhomboidea) and also for two of Kingma's 1948 species (N. macropora and N. microreticulata).The taxonomic confusion within the genus, particularly with respect to N. crispata, N. delicata, N. dongtaiensis, N. iniqua and N. microreticulata, is clarified and the zoogeographical implication of the distribution of the genus is discussed.     

Capacity building in the marine sector in the Pacific Islands: the role of the University of the South Pacific's Marine Studies Programme

Capacity building in the marine sector is a priority for Pacific Island nations, which face major challenges in the sustainable management of their marine resources under UNCLOS III and the various Conventions and Agreements stemming from UNCED. The University of the South Pacific (USP), with its 12 Pacific Island members (Cook Islands, Fiji, Kiribati, Marshall Islands, Nauru, Niue, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu, Vanuatu) has taken up this challenge through the establishment of its Marine Studies Programme (MSP) in 1993. The MSP is one of the four focal areas identified in USP's 1998 Strategic Plan. The breadth of MSP's activities is substantial, ranging from awareness raising at the village level to sophisticated post-graduate research in marine science. The substantial regional and international cooperation, research and training involved in these endeavours require USP to respond to education, training and research needs at many levels. As USP services more than 23 million square kilometres of ocean space and less than 1.7 million people, only a small percentage of this population have access to face-to-face teaching. USP's success to date is a measure of staff dedication, innovation and the confidence of the university, its members, and its donor partners. Capacity building in the marine sector will remain a high priority for many years to come, and MSP must continue to play a leading role.     

Direct barite determination using SEM/EDS-ACC system: implication for constraining barium carriers and barite preservation in marine sediments

Barite (BaSO₄) in marine sediments is considered as a proxy of surface ocean productivity and is widely used for paleo-productivity reconstructions. However, direct barite determination is not achieved by currently used methods, which rely on the measurement of total barium by inductively coupled plasma–mass spectrometry (ICP-MS) and instrumental neutron activation analysis (INAA) and correction from the allogenic Ba contribution. We report here on a technique that directly counts individual barite crystals using a scanning electron microscope (SEM) coupled to an energy dispersive spectrometer (EDS) equipped with an automated particle counting and classification (ACC) system. We show that barite–Ba concentrations can be deduced from the abundance, shape and size distributions of barite crystals with current precision and sensitivity as high as ±5 wt.% (2σ confidence limit) and 10 ppm, respectively. This technique, coupled with ICP-MS and INAA techniques for total Ba measurements, was applied to sediment samples from the tropical North Atlantic and the Central North Pacific oceans. Results show that: (1) barite and detrital aluminosilicates are the two main carriers of Ba in the investigated sediments; (2) calculated Ba/Al ratios range from 0.005 to 0.008 with an average value around 0.0066, in close agreement with previously reported values; (3) barite might not be the major source for released barium out of sediments and we suggest instead adsorbed barium as a potential source.     

Renewable energy from the ocean

Growing concern over the threat of global climate change has led to an increased interest in research and development of renewable energy technologies. The ocean provides a vast source of potential energy resources, and as renewable energy technology develops, investment in ocean energy is likely to grow. Research in ocean thermal energy conversion, wave energy, tidal energy, and offshore wind energy has led to promising technologies and in some cases, commercial deployment. These sources have the potential to help alleviate the global climate change threat, but the ocean environment should be protected while these technologies are developed. Renewable energy sources from the ocean may be exploited without harming the marine environment if projects are sited and scaled appropriately and environmental guidelines are followed.     

Uncertainties in field-line tracing in the magnetosphere. Part I: the axisymmetric part of the internal geomagnetic field

The technique of tracing along magnetic field lines is widely used in magnetospheric physics to provide a magnetic frame of reference that facilitates both the planning of experiments and the interpretation of observations. The precision of any such magnetic frame of reference depends critically on the accurate representation of the various sources of magnetic field in the magnetosphere. In order to consider this important problem systematically, a study is initiated to estimate first the uncertainties in magnetic-field-line tracing in the magnetosphere that arise solely from the published (standard) errors in the specification of the geomagnetic field of internal origin. Because of the complexity in computing these uncertainties for the complete geomagnetic field of internal origin, attention is focused in this preliminary paper on the uncertainties in magnetic-field-line tracing that result from the standard errors in just the axisymmetric part of the internal geomagnetic field. An exact analytic equation exists for the magnetic field lines of an arbitrary linear combination of axisymmetric multipoles. This equation is used to derive numerical estimates of the uncertainties in magnetic-field-line tracing that are due to the published standard errors in the axisymmetric spherical harmonic coefficients (i.e. g_n⁰ ± g_n⁰). Numerical results determined from the analytic equation are compared with computational results based on stepwise numerical integration along magnetic field lines. Excellent agreement is obtained between the analytical and computational methods in the axisymmetric case, which provides great confidence in the accuracy of the computer program used for stepwise numerical integration along magnetic field lines. This computer program is then used in the following paper to estimate the uncertainties in magnetic-field-line tracing in the magnetosphere that arise from the published standard errors in the full set of spherical harmonic coefficients, which define the complete (non-axisymmetric) geomagnetic field of internal origin. Numerical estimates of the uncertainties in magnetic-field-line tracing in the magnetosphere, calculated here for the axisymmetric part of the internal geomagnetic filed, should be regarded as first approximations in the sense that such estimates are only as accurate as the published standard errors in the set of axisymmetric spherical harmonic coefficients. However, all procedures developed in this preliminary paper can be applied to the derivation of more realistic estimates of the uncertainties in magnetic-field-line tracing in the magnetosphere, following further progress in the determination of more accurate standard errors in the spherical harmonic coefficients.Also Visiting Reader in Physics, University of Sussex, Falmer, Brighton, BN1 9QH, UK     

Carbon stars in infrared surveys

In order to prepare the analysis of the forthcoming near-IR surveys (DENIS, 2MASS) and to interpret them in terms of galactic structure and AGB evolution, we present model predictions of AGB distributions in K, in 12m and in (J-K, [12–25]) space, as they will be obtained from these surveys, cross-correlated with IRAS Catalog. The simulations have been made by adding the AGB to the Besançon model.     

Introduction

An ICES Symposium on The Influence of Climate Change on NorthAtlantic Fish Stocks was held in Bergen, Norway, from 11 to14 May 2004. The Symposium, sponsored by the ICES/GLOBEC WorkingGroup on Cod and Climate Change (WGCCC) as part of their synthesisactivities, was convened to address the issue of climate variabilityand its impact on cod and other fish stocks in the North Atlantic.It followed 11 years after the first WGCCC-sponsored ICES Symposiumon Cod and Climate (ICES, 1994) in Reykjavík, Iceland,which was convened to gather together the then current knowledgeof the influence of climate variability on cod. The 2004 Symposiumwas timely     

Seasonal cycle of suspended barite in the mediterranean sea

Biogenic barium (Ba_xs) was measured in suspended particles at the DYFAMED site in the northwestern Mediterranean Sea, on a monthly basis between February and June 2003. The barium content of barite (BaSO₄) micro-crystals was investigated using Scanning Electron Microscopy (SEM). Suspended particles were collected by filtration of small volumes of seawater (∼10 L), as well as large volumes up to 2400 L in March and in May. The Ba_xs profiles obtained from small-volume filtration display the typical mesopelagic maximum reported by earlier studies at ∼200 m depth, with concentrations up to 595 pmol L⁻¹. In addition, suspended Ba_xs was found almost exclusively in the form of micro-crystalline barite, except in February. The Ba_xs profiles obtained from large-volume filtration are consistent with the small-volume filtration findings, but reveal a significant Ba_xs peak of 1698 pmol L⁻¹ in the surface waters in May. Seasonal sampling at the DYFAMED site shows a net increase in barite concentration during phytoplanktonic blooms, confirming the involvement of biological systems in barite formation, as well as the potential role of barite as a primary productivity tracer. In addition, the coincidence between the mesopelagic barite maximum and the oxygen minimum layer suggests that barite is primarily found at depths of intense remineralization, in agreement with the hypothesis that barite forms within microenvironments of decaying organic matter.     

Mineralogy and origin of rhizoliths on the margins of saline,alkaline Lake Bogoria,Kenya Rift Valley

A wide range of rhizoliths occurs around the margins of Lake Bogoria, Kenya. These include root casts, moulds, tubules, rhizocretions, and permineralised root systems. These rhizoliths are variably composed of opaline silica, calcite, zeolites (mainly analcime), fluorite, and possibly fluorapatite, either alone or in combinations. Some rhizoliths are infilled moulds with detrital silicate grains. Most rhizoliths are in situ, showing both vertical and horizontal orientations. Reworked rhizoliths have been concentrated locally to form dense rhizolites.Hot-spring fluids, concentrated by evapotranspiration and capillary evaporation, have provided most of the silica for the permineralisation of the plant tissues. Precipitation involved the growth of silica nanospheres and microspheres that coalesced into homogeneous masses. Calcite rhizoliths formed following evaporative concentration, evapotranspiration, and (or) CO₂ degassing of Ca-bearing runoff water that infiltrated the sediment, or by mixing of runoff with saline, alkaline groundwater. Fluorite precipitated in areas where mixing of hot-spring and meteoric waters occurred, or possibly where hot-spring fluids came into contact with pre-existing calcite. Zeolitic rhizoliths formed during a prolonged period of aridity, when capillary rise and evaporative pumping brought saline, alkaline waters into contact with detrital silicate minerals around roots.