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Volume 24 (1990)
- Issue 6 Pages 349-
- Issue 5 Pages 309-
- Issue 4 Pages 193-
- Issue 3 Pages 123-
- Issue 2 Pages 47-
- Issue 1 Pages 1-
Volume 24, Issue 4
Displaying 1-13 of 13 articles from this issue
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Peter G. Brewer, Shizuo Tsunogai, C. S. Wong1990 Volume 24 Issue 4 Pages 193-195
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSDownload PDF (748K) -
Yasufumi Mishima, Shigeru Montani, Tomotoshi Okaichi1990 Volume 24 Issue 4 Pages 197-206
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSLarge amorphous aggregates, called “NUTA” (Japanese fisherman's jargon), were collected during 1986-1988, using a NUTA trap system in Osaka Bay, the Seto Inland Sea. These particles adhere to mooring ropes and fishing nets. To clarify the nature and distribution of NUTA, this study determined the organic matter composition of NUTA and those of suspended and sinking particles. The results revealed that the nature and distribution of NUTA are different from those of suspended particles. For example, the C/ATP and C/Chla ratios of NUTA were several times higher than those of the suspended particles. Cluster analysis of the amino acid composition of three types of particles showed that NUTA were more similar to sinking particles than to suspended particles. It can be considered that NUTA are formed by the decomposition of phytoplankton into detritus.View full abstractDownload PDF (2026K) -
Hisashi Narita, Koh Harada, Shizuo Tsunogai1990 Volume 24 Issue 4 Pages 207-216
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSSettling particles at 640 m, 1390 m, and 1920 m depths in the Okinawa Trough and bottom sediments at six sites in the East China Sea were analyzed for U and Th isotopes, 210Pb, and 210Po. Concentrations of 212Th in the settling particles were higher than those observed in the open ocean and were relatively constant with depth compared with other radiogenic nuclides. Fluxes and concentrations of these radiogenic nuclides increased with depth and the measured fluxes were larger than those calculated from water column inventories. While sinking through the water column of 640-1390 m, the increases in 210Pb and unsupported 228Th fluxes originating intensively in the shelf region were much larger than the unsupported 230Th fluxes produced evenly in sea water. The 210Po/210Pb activity ratio in the settling particles was almost unity and the 228Th/230Th activity ratio of the radiogenic fraction was much smaller than the ratio of the production rates of these nuclides in the shelf water. These results suggest that a large fraction of the deeper settling particles, as well as the sediments in the trough zone originating in the continental shelf zone, are transported laterally and downward via the near bottom layer on a time scale of approximately 16 years on the average.View full abstractDownload PDF (2975K) -
Kimitaka Kawamura, Nobuhiko Handa, Yoshiyuki Nozaki1990 Volume 24 Issue 4 Pages 217-222
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSA homologous series of C5-C17 ω-oxocarboxylic acids were detected in the deep-sea sediment trap samples collected from the Japan Trench, and in the bottom sediments from the North Pacific by using capillary GC and GC-MS techniques. Their distributions were characterized by the predominance of 9-oxononanoic acid (C9), being similar to the distribution patterns reported for remote marine aerosols. Since the ω-oxoacids are mostly produced in the marine atmosphere by the photochemical degradation of biogenic unsaturated fatty acids and supplied to the surface ocean by precipitation, these compounds are presumably transported in association with settling particles from the ocean surface to the deep-sea environments. Thus, the ω-oxocarboxylic acids are potential tracers of organic matter originating in the atmosphere and transported to deep-ocean waters.View full abstractDownload PDF (1722K) -
Boonsom Porntepkasemsan, Ahmad E. Nevissi1990 Volume 24 Issue 4 Pages 223-228
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSA study was conducted in Puget Sound, Washington, USA, to evaluate the accumulation of radium-226 in benthic fishes. The radium content of whole fish ranged from 0.83 to 20.33 pCi/kg wet weight and the calcium content ranged from 114 to 259 mg/g ash. Basically, no consistent correlation was found between radium and calcium concentration in fish. The concentration factor for transfer of radium from seawater to benthic fish ranged from 8 to 184 which is much lower than the corresponding values for the pelagic fish.View full abstractDownload PDF (1295K) -
Vertical-change index for the particulate transport of chemical and isotopic components in the oceanShizuo Tsunogai, Shinichiro Noriki, Koh Harada, Kazuhisa Tate1990 Volume 24 Issue 4 Pages 229-243
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSData obtained by recent sediment-trap experiments were compiled to discuss the mechanism for the removal of trace metals from the ocean. The vertical-change index (IM), or the rate constants of first-order change with depth, were estimated. The results and the IM values in km-1 shown in parentheses are as follows. The total particulate matter flux(-0.05) is nearly constant with depth due to rapid sinking of its major components of tests of biogenic silica(-0.03) and calcium carbonate(-0.05) to the bottom. The organic fraction(-0.27) of settling particles reduces with depth together with components contained in soft tissue of organisms such as Cd(-0.23). The fluxes of the lithophile components of Al(+ 0.22), Fe(+0.17), and 232Th(+0.19) largely increase with depth due to the lateral transport of particles from the continental margin. The large index of Mn(+0.47) is due to the early diagenetic process in the surface sediment in addition to the simple resuspension. The flux of short-lived 234Th(-0.01) is saturated, but that of 228Th(-0.14) having no substantial source in the pelagic ocean is the smallest among radiogenic nuclides in seawater. The largest index is found for the long-lived radionuclides such as 230Th(+0.50) and 231Pa(+0.56). The effect of radioactive decay is somewhat reflected in the indices of 210Pb(+0.41) and 210Po(+0.43). These results support the train-passengers model proposed by Tsunogai (1987) for the behavior of chemical elements in the ocean.View full abstractDownload PDF (2915K) -
Yoshiaki Maita, Mitsuru Yanada1990 Volume 24 Issue 4 Pages 245-254
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSIn order to reveal the vertical distribution of dissolved organic nitrogen (DON) in seawater, a critical examination is made of two the analytical methods for the constituents, i.e. the persulfate oxidation method and the high-temperature catalytic oxidation (HTCO) method with platinum (Pt) or manganese (Mn) as the catalyst. The analytical values of total dissolved nitrogen (TDN) from the HTCO method agreed very closely with the values obtained by the persulfate oxidation method for several standard organic nitrogen compounds, humic acid prepared from marine and lake sediments, and natural seawater samples. Both of the catalysts, Mn and Pt used in the HTCO method, provided reproducible data for the TDN analysis. The concentrations of TDN changed vertically by both methods in a manner similar to those of nitrate nitrogen. The concentration of DON in seawater, expressed as the difference of TDN and dissolved inorganic nitrogen (DIN), was in the range of 1∼10 μg at N·1-1 from the surface to 2000 m depth at several stations in the North Pacific Ocean. In the subsurface water from 0 to 200 meter depth, DON showed an inverse correlation to nitrate with statistical significance. The gradient of NO3/DON by atom base was ca. -4 for the subsurface samples, indicating that about 25% of NO3 was apparently regenerated from the DON fraction, but no correlation was found below 200 m depth, suggesting. that DON in the deeper layer was relatively refractory for biological activity.View full abstractDownload PDF (2302K) -
Tatsuo Aono, Yuzuru Nakaguchi, Keizo Hiraki, Takayuki Nagai1990 Volume 24 Issue 4 Pages 255-261
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSOrganic compounds in sea water samples were separated by the hollow-fiber ultrafiltration and Sephadex G-15 gel filtration methods. Chemical species of organic selenium compounds in sea water were then determined using the fractional-determination method of organic compounds which was established by Starikova (1962). The application of this method for a separation and determination of seleno-amino acid was investigated by adding radioactive L-[75Se] selenomethionine and/or 75Se as a tracer. The recovery values of the L-[75Se]selenomethionine tracer method were 93% in artificial sea water and 83% in Lake Biwa water. This fractional-separation method gave good results for the determination of seleno-amino acid in sea water samples. The concentration of seleno-amino acid in sea water samples taken from around the Bering Sea were determined as 4-20 pM.View full abstractDownload PDF (1743K) -
Masashi Kusakabe, Teh-Lung Ku, John R. Southon, Christopher I. Measure ...1990 Volume 24 Issue 4 Pages 263-272
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSVertical profiles of 9Be and 10Be have been determined in the ocean. The nutrient-like recycling behavior for both Be isotopes, involving surface scavenging and deep-water regeneration, is manifested by their vertical profiles in the borderland basin off southern California, in the Pacific and in the Bering Sea. In contrast, in the western N. Atlantic, the concentrations of 9Be are almost vertically constant (or slightly higher in the surface than in the deep), and the concentrations of 10Be generally show minor surface depletion and are lower than those of the Pacific. The 9Be profiles in the S. Atlantic are generally similar to those of the Pacific except for a station close to the plume of Saharan desert dust, which shows surface enrichment. We interpret the vertical distributions and their differences among stations in terms of intense surface 9Be input (especially eolian input) to the Atlantic, a relatively uniform oceanwide pluvial input of 10Be, the particle reactive nature of Be, and the oceanic residence time of Be. Material balance calculations using a two-box (coastal and open oceans) model point to the importance of coastal ocean as a sink for both Be isotopes and eolian dusts as a source of oceanic 9Be.View full abstractDownload PDF (2628K) -
Hideo Yamazaki, Shiro Gohda1990 Volume 24 Issue 4 Pages 273-281
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSInvestigations are made to determine molybdenum species in sea-water samples collected from the Seto Inland Sea, the Japan Sea, the Bering Sea, and the western North Pacific. A large portion of the molybdenum species in sea waters exists as a hexavalent oxoacid anion (MoO2-4), but an appreciable amount of molybdenum was found as an unextractable species with an 8-quinolinol-DIBK system in the high-molecular weight species. Total dissolved molybdenum was uniformly distributed in oceanic waters at a concentration level of 8.10 to 12.0 μg/l (average, 10.2±0.90 μg/l). In coastal waters, however, great spatial and temporal variations were observed. The concentration of unextractable molybdenum was relatively high in the coastal waters (0.60±0.52 μg/l) and in the shallow waters of the open oceans (0.40±0.33 μg/l), while it was not large in the deep waters (0.28±0.27 μg/l). High molecular-weight molybdenum, which has a molecular weight over 10, 000, was sometimes observed. The molybdenum was randomly distributed and not related to the distribution of the unextractable species. The unextractable and/or high molecular-weight molybdenum, which is probably associated with organic substances, may significantly contribute to the biological cycle of molybdenum in a productive area.View full abstractDownload PDF (2040K) -
Kiminori Shitashima, Hiroyuki Tsubota1990 Volume 24 Issue 4 Pages 283-293
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSTotal and dissolved concentrations of heavy metals—V, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd and Pb—in the Seto Inland Sea and in surface water from the adjacent seas of Japan have been determined. The water samples were collected with a specially designed clean sampler, and particulates were separated by filtration and/or centrifugation in a clean bench on board ship or in a clean room on land. The heavy metals were preconcentrated with a chelating resin column and detected by GFAAS in a clean laboratory on land. All the elements analyzed were divided into three groups in accordance with the ratio of dissolved to total concentrations for the Seto Inland Sea. Fe, Mn and Pb were mostly particulate forms, while Cu, Zn and Co were divided fifty-fifty between dissolved and particulate forms. Cd, Ni, Mo and V were almost dissolved forms. Two different methods for separating particles were compared to determine the characteristics of particulates. The flux of heavy metals from the Inland Sea to the open ocean was estimated, assuming that only the dissolved forms of the metals are transported outward.View full abstractDownload PDF (2756K) -
Lu Xiankun, Yang Min, Shi Jiande, Feng Xiaoju1990 Volume 24 Issue 4 Pages 295-308
Published: 1990
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSMercury content of the sediments and water in the area of the Huanghe Estuary and adjacent sea was measured for several species. The content values were found to be among the lowest levels in the world estuaries. The distributions, more or less homogeneous in dry season while exhibiting a gradient during the flood season, show the main role of the Huanghe runoff, having a heavy load of silt. Also observed were the transformation of inorganic mercury into organic species during the mixing between fresh and saline waters, rectilinear correlation of sediment mercury to its median diameter, and the stratification of mercury species at the near estuary.View full abstractDownload PDF (2640K) -
1990 Volume 24 Issue 4 Pages e1
Published: 1990
Released on J-STAGE: February 06, 2009
JOURNAL FREE ACCESSDownload PDF (304K)
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