Three active hydrothermal fields were located at 13N, south Mariana Backarc spreading center. Time series study of fluid chemistry was conducted using SHINKAI6500(JAMSTEC) and ROPOS(CSSF) from 2003 to 2005,and their results will be discussed.

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Core samples and chimney samples were collected in Suiyo Seamount and Mariana submarine hydrothermal systems. Concentration of amino acids, their enentiomeric ratios and phosphatase acitivities were determined in them. Vertical profiles of amino acids and phosphatase activities showed maxima in the middle of the cores of Suiyo Seamount, which suggested the presence of a sub-surface biosphere. In Mariana, however, only at the top surface or the cores showed high phosphatase activities. Outer part of the chimney samples showed higher phosphatase activities than inner part which had faced to hot media. The present results suggest that phosphatase activities are good biomarkers for extant life.

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In order to develop new techniques and instruments for in situ measurement, we conducted combined measurement of physical, chemical and biological activities during the scientific exploration in the area of Hatoma Knoll in April to May, 2005. In this exploration, we first deployed a newly developed 'Integrated in situ Analyzer-Gene (IISA-Gene)', which is a micorfluidics-based instrument capable of doing PCR (polymerase chain reaction) in deep sea environments. In this paper, the overview of the system and the results of the first deployment will be described. Some perspectives for further development of the technologies for combined in situ measurement will also be discussed.

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Taketomi submarine hot spring was located at bottom of Sekisei lagoon (about 20m below sea surface), 500m east from Taketomi island. It is noted that hydrothermal fluid and gas are venting in this hot spring field, where fringing coral reefs are widely distributed. In the shallow hot spring filed, chemosynthetic organisms can habitat similarly to deep sea hydrothermal vent field. We are interested in the relationship between the chemosynthetic and photosynthetic ecosystems. The purpose of this study is to observe the spatial distribution of physical and chemical condition around the Taketomi hot spring, and to discuss on the influences of hot spring on the surrounded coral reef ecosystem.

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Factors influencing bacterial Mn(II) oxidation by the multi-copper oxidase-like enzyme on the spore of the marine Bacillus sp. SG-1 are examined in time course experiments with initial Mn (II) concentration between 0.03mM and 0.05mM. Ca2+ ions have a dramatic effect on the oxidation in artificial seawater, while Mg2+, Sr2+, K+, NO3- have no effects. The rate at 10mM of Ca2+ ions (seawater composition) was four or five times that with no Ca2+ ions.

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To discuss the possibility of biota-involved regulation of a condition of the earth, which is not a resource (e.g., temperature), it is useful to investigate "independent regulation" systems. An attempt has been made to find a mechanism to generate the selective or suppressive pressure through an independent regulation mechanism (Biotic Independent Regulation: BIR). In this brief paper, we propose a simple abstract model, which select a favorable species (or suppress an unfavorable species) without employing local effects.

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Environmental conditions (ex. Temperature, pH) in many natural systems seem to be altered by some organisms and biota-involved self-regulatory models has been reported. We simulated feedback models between environmental condition and species, which compete for same limiting resources, and examined the cause of biotic environmental regulation. We adapted well-known nutrients competition to plankton species and introduced an assumption that the species has an environment (temperature in this case) altering trait. We will report simple abstract models of biotic environmental regulation, which is emerged from the interaction between species and resources.

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BBased on the proximity of fine roots to rock is to weathering, we designed two types of hydroponic crop pots by using two types of mesh sized net. We did experiments with three crop species and two types of rock, separately. All plants accelerated in the release of elements. Basalt released more than andesite. Significant difference in the released amounts of elements between the coarse and fine net pots was observed for maize and soybean in andesite and basalt experiment, respectively. The results imply that weathering may be caused partially by the direct contact of fine roots with rock particles.

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Although the Sea of Okhotsk is characterized as the lowest latitudinal area of seasonal sea-ice in the world, the influence of sea-ice to biological production have not been well understood in the Sea of Okhotsk. In fact, the sea-ice does not contribute the primary productivity very much, but it produces a dense shelf water which penetrates into offshore intermediate water carrying large amount of organic matter produced on the continental shelf under the influence of river water discharges. This organic-rich intermediate water does not only support large heterotrophic biomass there, but also may contribute the primary production in the northwestern North Pacific via vertical mixing of the terrestrial nutrients at Kuril straits.

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Resent studies indicated that iron is an important factor controlling phytoplankton growth in subarctic North Pacific. In this study, we observed vertical profile of iron in the western subarctic North Pacific, Oyashio-region, and the sea of Okhotsk, and we discuss that the Sea of Okhotsk may have very important role for iron supply to the western subarctic Pacific. There are several reports indicate water export from the Sea of Okhotsk into the western subarctic Pacific through Kuril islands. Therefore, it can be considered that seawater, which contains iron in high concentration, exported into the subarctic Pacific from the Sea of Okhotsk, and have influence on biological response in the western subarctic Pacific, especially in Oyashio region.

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A time series sediment trap was deployed in the eastern side of teh Japan basin. Lead-210 in the settling particles was measured. Lead-210 flux in the deep basin was higher than that expected by the total flux of the atmospheric deposition and the removal from seawater, and that observed in the wastern side of the Japan Basin reported. The reason was disccused.

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We are observing air pollutants including aerosols transported from East Asia in China and at Cape Hedo, the northernmost end of Okinawa Main Island. The observation in China was made as the aerial observations carried out in the mainland China and synchronized ground-based observations. Four campaign were madefrom 2002 to 2004. In observation near the large emission source area in China negative correlation of NOx with ozone and good correlation of NOx with SO2 were seen. As for the aerosol chemical composition, good correlations between NO3, SO4 and NH4, Ca were observed over China, which indicated that acidic species were well neutralized with ammonia. Acidic species increases over the East China Sea along the long-range transport, and acids exceed bases in Okinawa.

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Samples from a recent 15-year time-series of sediment trap experiment in the North Pacific subpolar region, reveal that both the opal flux (OP) and organic carbon flux (OC) mainly had significant linear decreasing trends in the first half of year (OP: -6 to -47 mg/m2/yr; OC: -1 to -9 mg/m2/yr). Furthermore, OP/CaCO3 flux(OP/CC) also had diminished with -0.2 to -0.6/yr, which are the largest decreasing rate in the world ocean. These facts suggest a evidence that occurrence of recent shift in the marine biological species from diatom to coccolithophorids with the decrease of biological activities in the North Pacific, which consequently would cause the reduction of efficiency of absorption of CO2 between air and sea.

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Dissolved Zr, Hf, Nb, Ta and W in seawater sample were concentrated using TSK-8HQ chelating resin and were determined by ICP-MS. In a previous study, MAF-8HQ chelating adsorbent was used to concentrate these metals from seawater, however, it was difficult to reduce the blank and to elute the metals quantitatively.

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The classical analytical method of DMS in seawater (Purge & Trap, P&T))is complicate on shipboard. It is difficult to obtain a lot of data for understanding spatiotemporally for DMS. Recently, new analytical method by using SPME (Solid-Phase Micro Extraction) has been developed. If it is possible to preserve DMS with SPME, it would be promising as the future global standard. Our purpose was to establish long-term preservation of DMS with SPME. The preservative efficiency was 96.1+/-5.7% during 20 days, which agreed with the observed DMS in situ(r2=0.85, P<0.0001). We also estimated the distribution coefficient derived from the salinity to be 0.1nM/%o-Sal,suggesting no influence of salinity in open oceans. The above results can allow us to find SPME method useful.

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To understand the origins and transport processes of lithogenic particles in the western North Pacific, time-series sediment traps were deployed at Sta. KNOT(44N, 155E) during 2002-2004, and size-distribution, REEs, Th and Sc of sinking particles were measured. In the time of much input of KOSA, lithogenic particle size distribution had two peaks: in the vicinities of 3-4 um and 10 um. We divided these particles into large lithogenic particles (LLP) and small lithogenic particles (SLP) by the inflection point of size distribution. The SLP flux was increased with depth. This finding suggests that SLP is horizontally transported to the deep ocean. Chemical components of particles indicate that origin of LLP is mainly KOSA in spring and is Kurile-Kamchatka Islands in the other seasons.

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The Okhotsk Sea, its sea ice expansion in winter season is sensitively affected by global warming and cooling. Therefore, the environmental change in the Okhotsk Sea would be a good sensitive mirror to reflect the global and the regional climate changes. In order to better understand how the surface environmental change in the Okhotsk Sea had potential influencing the climate change in the East Asia, SSTs were estimated in the southwestern Okhotsk Sea during the past 10 kyr with millennial-centennial time resolution using the long-chain unsaturated alkyl ketones (alkenones) thermometer. A sediment core was collected at Off Shari in the southwestern Okhotsk Sea (MD01-2412, 44.31N, 145E, WD1,225m) during an investigation of IMAGES.

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The behaviour of chalcophile elements (e.g. PGE, Re, Cu) in subduction zones is poorly understood. Although mainly controlled by sulfide species, Cl-rich fluids may also mobilize the chalcophile elements. Southern Kermadec Arc lavas are enriched in Cl-rich slab-derived fluid components. We will present Re-Os isotopic data and complementary elemental data for both typical and high-K lavas from Clark volcano, within a framework of slab-derived fluid mobility in the southern Kermadec Arc.

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An important advance in the FTIR technique in the past decade has been the advent of spectroscopic imaging, which allows a map of the volatile species of interest to be constructed from 4096 simultaneously collected spectra, each of which has a sensitivity approaching larger analyses using conventional FTIR techniques. Here, we introduce the technique and apply it to the analysis of volcanic glasses and melt inclusions from the Izu-Bonin arc to test models for silicic crustal growth, such as differentiation of basaltic material or from melting of pre-existing andesitic lower crust.

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Hydrogen bonds in dense hydrous magnesium silicates will be reviewed.

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We propose the way to estimate water content and geotherm in the upper mantle using electrical conductivity and seismic P-wave velocity distribution. First we assume the dry (water content=0) condition, and estimate geotherms in the upper mantle using only electrical conductivity or P-wave velocity distribution, respectively (electircal geotherm and seismic geotherm). When the electrical and seismic geotherms are consistent with each other, we interpret the upper mantle is dry and the geothermal structure is electrical or seismic geotherm. If electrical and seismic geotherm is inconsistent, we introduce hydorgen dissolution. The hydrogen dissolution is estimated by electrical conductivity assuming that seismic geotherm reflects an appropriate upper mantle geotherm.

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