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012992B.CHM
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Country: Japan
From: Report of oceanographic studies in Japan for the period from
1987-1990- by Japanese National Committee for Physical Sciences of
the Ocean- Science Council of Japan.
Prepared for IAPSO (International Association for the Physical
Sciences of the Sea) for presentation at XX General Assembly of the
International Union of Geodesy and Geophysics: Vienna, Austria:
August 1991.
p. 20-40
II. CHEMICAL OCEANOGRAPHY
Shizuo Tsunogai, Faculty of Fisheries, Hokkaido University,
Hakodate 041, JAPAN
In this four years(1987-1990), chemical oceanographic works in
Japan were supported by some fairly large cooperative projects such
as "Dynamics of the Deep Ocean Circulation (represented by Prof. T.
Teramoto)" and "Formulation and Management of Man -Environment
System (represented by Prof. M. Suzuki)" both for scientists in
universities besides individual projects proposed to the respective
agencies. Chemical oceanographic studies on board R. V. Hakuho Maru
of Ocean Research Institute, University of Tokyo carried out in the
western North Pacific (KH-87-2), the eastern North Pacific (KH -88-
3) and the equatorial Pacific(KH-90-3). Vessels of other
universities and governmental agencies were also well used for
research. These projects and cruises have highly stimulated us and
brought forth many valuable works, which are listed below.
On the other hand, the population of Japanese chemical
oceanographers has not so increased. This is due to a small number
of laboratories studying chemical oceanography in universities
especially in graduate schools. Only one chemical laboratory was
newly opened in Department of Marine Science and Technology in
Hokkaido Tokai Univ. (Sapporo) in 1988. Recently many governmental
research institutes have become aware of the importance of chemical
oceanography or the weakness of their chemical division, and
gradually reinforced their chemical aspect by employing new
scientists. They are Japan Meteorological Agency including
Meteorological Research Institute, National Research Institute for
Pollution and Resources, Government Industrial Research Institute,
National Institute for Environmental Studies, National Institute of
Radiological Science, Japan Atomic Energy Research Institute, Japan
Marine Science and Technology Center, etc. The scientists in these
research institutes will add many fruitful oceanographic works in
the next period of four years. The scientists studying in academic
positions have also taken an active part in Japanese chemical
oceanography. They are belonging to Faculty of Fisheries, Hokkaido
Univ.; Ocean Research Institute and Faculty of Science, Univ. of
Tokyo: Tokyo Univ. of Fisheries; Faculty of Science, Tokyo
Metropolitan Univ.; Faculty of Agriculture, Tokyo Univ. of
Agriculture and Technology; Faculty of Marine Sciences. Tokai
Univ.; Faculty of Science, Toyama Univ.; Water Research Institute,
Nagoya Univ.; Faculty of Biological Resources, Mie Univ.; Faculty
of Science, Kyoto Univ.; Faculty of Science and Technology, Kinki
Univ.; Faculty of Integrated Arts and Sciences, Hiroshima Univ.;
Faculty of Agriculture, Ehime Univ. and Faculty of Science, Univ.
of Ryukyus. The studies carried out by them are given below with
brief comments. 1. General and Physical Oceanography Studied with Chemistry
The usefulness of dissolved silica as a tracer of deep water movement
has been clarified (Tsunogai, 1987), where the Pacific Deep Water flows from
the deep western North Pacific to the deep central and eastern North Pacific
via the northern end of the Emperor Sea- mountains along the Kurile and
Aleutian Trenches.
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . .6 Citations
2. Physical Chemistry
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Citation
3. Chemistry of Anoxic Water
The blue tide, Aoshio, was extensively studied by T. Samukawa and his
colleagues (Natl. Res. Inst. Poll. Resour.)
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . .5 Citations
4. Analytical Chemistry
E. Nakayama (Kyoto Univ.)'s group studied the followings. A column
extraction method using macroporous resin impregnated with 7-dodecenyl
-8-quinolinol (Chelex-100 column) was utilized for simultaneous
preconcentration of common heavy metals as well as other column
extraction methods for Co and Cr in seawater. The polarographic catalytic
currents obtained in a special electrolytic solution have been applied to
the simultaneous determination of W and Mo in oceanic water found to
contain ca. 60 pM of Mo. Furthermore, an automated flow-system suitable to
the on-board analysis of Mn in seawater was constructed.
K. Fujiwara and his colleagues (Hiroshima Univ.) developed new
analytical methods of phosphate and As and applied to seawater. The new
technique was ozone-gas phase chemiluminescence for As.
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 30 Citations
5. Gases and Marine Atmosphere
The determination of pCO2 of seawater was continued by H. Inoue and
his colleagues (Meteorol. Res. Inst.). The time-series measurements in the
western North Pacific will give valuable information to the global change
studies.
T. Suzuki and his colleagues (Hokkaido Univ. ) studied the long- range
transport of aerosol of continental origin to the ocean by making an
observation network with US scientists.
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . .12 Citations
6. Trace Elements
K. Matsunaga and his colleagues (Hokkaido Univ.) have revealed the
following. The distribution of trace metals and nutrients in seawater is
controlled by biogeochemical process. They examined the mechanism that
controls the seasonal variations of Cd and P04 in the euphotic zone in
Funka Bay, Japan (Abe and Matsunaga, 1988; Abe et at., 1990 ). They also
observed the high Fe(II) concentration, which is extremely unstable in oxic
seawater, during a spring bloom (Nakabayashi et at., 1989 ). The behavior of
trace metals and nutrients was examined in the Yodo River Estuary, Osaka
Bay where red tide outbreaks are observed (Kudo and Matsunaga, 1989). The
origin of nutrients rich in the Tsushima current was also investigated
(Toya et al., 1988).
6a. Concentration in sea water
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 12 Citations
6b. Metal-organic ligand complexes
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . .5 Citations
7. Radioisotopes
Y. Nozaki and his group (Univ. of Tokyo) continued to measure natural
radioisotopes in seawater. Many Japanese works obtained for radioisotopes
have been discussed to make clear the behavior of chemical elements in the
marine environment, the physical water movement (advection and diffusion)
and the biological activity in the ocean. The works in relation to the
particulate removal in the ocean are given in Section 11a, although
Kusakabe et at. (1988)'s work showed the rapid particulate transport in the
biologically active northern North Pacific. Tsunogai et at. (1990) clarified
that the coastal sediments are the most important sink of uranium in
seawater.
7a. Natural radioisotopes
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 17 Citations
7b. Artificial radioisotopes
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . .4 Citations
8. Stable Isotopes
N. Yoshida(Toyama Univ. ) developed a skillful technique to determine
isotopic ratios of nitrogen of N2O, which is a by-product of nitrification
and denitrification processes during the biological metabolism. These
stable isotopic studied will give valuable information on the oceanic
biological activity.
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . .6 Citations
9. Nutrients and Biochemistry
T. Saino (Univ. of Tokyo) studied the oceanic biochemical processes
chiefly with stable isotopes based on an extensive survey of vertical
profile of del-15N in POM, which revealed that the 15N abundance in deep
water POM is primarily determined by that in the near surface POM (Saino
and Hattori, 1987). Difference between del-15N and del-13C profiles of POM
was explained as resulted from the difference of refractory fraction in
POC and PON. It is proposed that del-13C and del-15N of POM provide
complementary information on POM dynamics (Saino, 1990).
K. Kobayashi (Yokohama National Univ.) studied large molecular weight
metal complexes dissolved in seawater and freshwater. The concentration
of such metal complexes were determined by ultrafiltration/high
performance gel chromatography/ICP optical emission spectrometry (or
graphite furnace atomic absorption spectrometry) (Kobayashi et at., 1990).
A part of such kinds of complexes were proved to be metalloenzymes like
alkaline phosphatase (Kobayashi and Haraguchi, 1989).
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 28 Citations
10. Organic Matter in Seawater
The concentration and the composition of dissolved organic nitrogen
(DON) were determined in the North Pacific Ocean using newly developed high
temperature oxidation method (given in Section 4). The significance of the
DON in the geochemical cycle of nitrogen was discussed in relation to the
hydrographical conditions, biological production and decomposition by Y.
Maita and his colleagues (Hokkaido Univ.). They showed that in the upper
water, DON existed as labile nitrogen which can easily be decomposed by
oceanic bacteria, i.e. low molecular weight organic nitrogen compounds,
whereas in the middle and deep waters, DON existed more as biochemically
refractive nitrogen. The vertical variation of DON was small as compared
with that of nitrate nitrogen and they suggested that DON was not
apparently the major source of nitrate nitrogen. The concentration of
dissolved organic carbon (DOC) was measured by Y. Suzuki and his colleagues
(Meteorol. Res. Inst.), but the data have not yet been published except one
report (Druffel et at.. 1989).
K. Hayase (Hiroshima Univ.) studied the fluorescent organic matter in
the North Pacific and Sagami Bay, Japan, showing that the vertical profile
was similar to that of phosphate of nitrate.
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 17 Citations
11. Particulates and Sediment Trap Experiments
Sediment trap experiments are now actively carried out by various
groups, but the published papers are not so many. S. Tsunoga1 and his
colleagues (Hokkaido Univ.) discussed the particulate removal of chemical
elements by proposing "Train-passengers model" (Tsunogai, 1987) and by
introducing the vertical change index for the lateral transport (Tsunogai
et al., 1990). They also gave attention to the oceanic carbon cycle (Tsuogai
and Noriki. 1987, 1991). K. Taguchi (Mie Univ. ) radiochemically investigated
settling particles collected by sediment traps in the high, latitudes of the
North Pacific. In the northern North Pacific, including the Bering Sea,
the average activity ratio of unsupported 230Th to 231Pa in settling
particles was 5.5. whereas that in the Gulf of Alaska in the eastern North
Pacific was about 14. It is suggested that 231Pa transported from
oligotrophic regions is being actively removed in the biologically
productive northern North Pacific (Taguchi et at., 1989).
11a. Inorganic matter
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . .8 Citations
11b. Organic matter
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 10 Citations
12. Sediments
A. Kamatani and his colleagues (Tokyo Univ. of Fisheries ) studied
followings. The dissolution kinetics of diatom silica skeletons and diatom
ooze from the Antarctic Ocean was investigated at various pH's and
temperatures. The slow dissolution rate of the ooze was mostly due to the
presence of inhibitors postfixed on the surface layer of silica skeletons,
which were partly removed by the acid treatment. The dissolution process
could be described by paraboric (?parabolic? PW) kinetics. On the other
hand, the dissolution of the silica skeletons which was prepared from living
diatom was shown by a simple first order equation.
Horizontal distribution of lignin components (CuO degradation
products), delta C-13 values, cellulose, polynuclear aromatic hydrocarbons
(PAH), alkylbenzene sulfonates (LAS) and linear alkylbenzenes (LABS) have
been investigated in the sediments of Tokyo Bay and adjacent areas by R.
Ishiwatari and his group (Tokyo Metropol. Univ.). The results have indicated
that these materials and parameters are very useful in understanding the
behavior of land-derived organic matter in bay and coastal regions.
Alkylbenzenes can be used as a tracer of domestic wastes. Land-derived
organic matter shows roughly two types of distribution in bay area
probably depending on density of carriers.
12a. Inorganic matter and interstitial water
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . .8 Citations
12b. Organic matter
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 10 Citations
12c. Ferromanganese nodules and authegenic matter
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . .4 Citations
13. Basalt and Hydrothermal Activity on the Ocean Floor
T. Gamo and his colleagues (Univ. of Tokyo) studied hydrothermal
activity at the Loihi submarine volcano and characterized it from water
profiles of dissolved CH4 pH and 3He. Apparently two distinct hydrothermal
plumes were identified to suggest that there are at least two chemically
independent vent systems in the Loihi area (Gamo et al., 1987). Cold seepage
at the Hatsushima Calyptogena community site in the western Sagami Bay
was also characterized from high values of CH4 and some trace metals in
the bottom seawater. Time scale for CH4 consumption was estimated by
applying a vertical diffusion model to CH4 and 222Rn profiles. Anomalously
high heat flow was found to accompany with the seepage at the site (Gamo et
al., 1988).
M. Kusakabe's group (Okayama Univ.) studied followings. Seawater
circulation through the oceanic crust at the spreading axes can give a
great influence on the chemical and isotopic compositions of the oceanic
crust due to extensive hydrothermal alteration. They characterized, in
terms of H. 0, S and Sr isotopic variations, the hydrothermally altered
rocks from a young oceanic crust drilled off Costa Rica during DSDP/ODP
project (Kawahata et at., 1987; Kusakabe et at.. 1989). Upon subduction,
such altered crust is dehydrated and supply water responsible for
serpentinization of wedge mantle in the forearc region (Sakai et at., 1990).
Venting of hot water at the spreading axis of backarc basin was first
recognized at Mariana Trough chimney materials and hot waters were found
similar to those of the midoceanic ridges except that the backarc chimneys
were enriched in Ba and Pb (Kusakabe et al., 1990).
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 19 Citations
14. Pollution
R. Tatsukawa and his coworkers (Ehime Univ.) have been engaged in the
research on the distribution, behavior and fate of persistent toxic
contaminants (particularly organochlorine compounds and heavy metals) in
riverine, estuarine, coastal and open ocean waters from a global point of
view. Concomitantly, biological contamination, bioaccumulation and
ecotoxicity of these chemicals have also been investigated using wide
range of marine organisms such as fish, reptiles. birds and mammals.
From the investigations conducted during the recent 4 years, it could be
pointed out that the increasing usage and disposal of toxic chemicals in
the tropical regions have a greater impact on marine environment,
particularly remote ocean areas including polar regions. Furthermore,
higher marine organisms such as whales and dolphins were recognized to be
most vulnerable to the toxic threat of persistent contaminants due to
specific biological and physiological processes like lack of detoxification
enzymes.
REFERENCES: . . . . . . . . . . . . . . . . . . . . . . . . . 34 Citations
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