Vertical distribution of heavy metals and its seasonal variations in Beppu Bay

From July to November, the thermocline which has strong temperature gradient (0.7C m^–1) is formed in the bottom water of Beppu Bay, and it prevents the downward mixing of surface water. This has caused the bottom water of the basin to become depleted in oxygen, and in November the bottom water below about 60 m depth becomes anoxic. Accordingly manganese and iron are reduced and more soluble under the anoxic condition, those concentrations are high relative to surface water, and the maximums are 1,240g l^–1 and 80g l^–1. Under the anoxic condition, the flux of dissolved manganese from the sediment is about 10g cm^–2 day^–1.     

Distribution of particulate organic carbon and nitrogen in the Bering Sea and northern North Pacific Ocean

Particulate matter was collected in the Bering Sea and the northern North Pacific Ocean during the cruise of R. V. Hakuho-maru, Ocean Research Institute of Tokyo University in summer of 1975. The particulate matter was analyzed for organic carbon and nitrogen, chlorophylla and amino acids.The concentrations of particulate organic carbon and nitrogen were measured with the range of 16–422gC l^–1 and 1–85gN l^–1, 19–186gC l^–1 and 1–26gN l^–1, 46–1,038gC l^–1 and 6–79gN l^–1 and 19–246gC l^–1 and 2–25gN l^–1 in the Oyashio, the Deep Bering Sea, the continental shelf of Bering Sea and the northern North Pacific, respectively. Particulate organic carbon and nitrogen decreased with depth throughout the areas. The average concentrations of organic carbon and nitrogen in the entire water column tended to decrease in the following order; the continental shelf > Oyashio > northern North Pacific > Deep Bering Sea.C/N of particulate matter varied in the range of 3–15 (7 on average) in surface waters throughout the areas and these values tended to increase with depth to 5–20 (11 on average) in deep waters without significant regional variability.Linear regressions between chlorophylla and particulate organic carbon in the euphotic layers indicate that detrital organic carbon accounted for 34.2, 44.9, 49.1 and 25.2 % of particulate organic carbon in the Oyashio, the Deep Bering Sea, the continental shelf and the northern North Pacific, respectively.Particulate amino acid was determined in the range of 10.3–78.0g l^–1, 104–156g l^–1 and 10.4–96.4g l^–1 in the Deep Bering Sea, the continental shelf and the northern North Pacific, respectively. Aspartic acid, glutamic acid, serine, glycine and alanine were found as dominant species of amino acid of particulate matter.     

The content and the oxidation state of arsenic and antimony in coastal water of Japan

The content and the oxidation state of arsenic and antimony in coastal seawater were determined coupled with chemical separation and neutron activation method. The contents of arsenic and antimony in coastal seawater were estimated to be 1.56–2.73g As/l, 0.25–0.57g Sb/l. Most parts of these elements exist as soluble ionic species, passing through 0.45 pore-size membrane filter, and at surface, 80–97% of arsenic occurs as arsenate and 70–94 % of antimony may occurs as antimonate. The vertical distribution of arsenite and arsenate is almost constant from the surface to 1,200 m depth. However the distribution of Sb(III) and Sb(V) is much more complicated with depth.     

Gallium content in seaweeds

Analyses of gallium content were made by the fluorometric method on 57 samples of seaweeds which were composed of 30 species. As the result of it, the gallium content was found ranging from 0.02 to 0.64g g^–1 and the average was 0.14g g^–1 in the dried seaweeds.Generally, the gallium content in seaweeds had a close relationship to the aluminium and iron contents. The average weight ratio of Ga/Al was 3.8×10^–4 and one of Ga/Fe was 4.0×10^–4. The average Ga/Al weight ratio (3.8×10^–4) was very similar to that reported for shallow-water deposits (2.1×10^–4), but was definitely lower than that in sea water (1.5×10^–2).     

Alkylbenzenesulfonate (ABS) in the bottom muds of the inner part of Tokyo Bay

The contents of alkylbenzenesulfonate (ABS) in the bottom sediments were analyzed for the inner part of Tokyo Bay and five inflowing rivers. Methylene blue active substances (MBAS) was extracted from the dired sample with methanol-benzene mixture.After the concentration of MBAS was determined by colorimetry, the ratio ABS/MBAS was estimated by an infrared spectrum of MBAS-MB complex. The net content of ABS was calculated from these two values.The ABS contents in the surface of the bottom sediments of the rivers and sea ranged 1.959g/g and 014.1g/g dry weight, respectively. The contents of ABS in the river sediments reflected the degree of pollution of each river by urban waste waters. From the results of the analysis of the core samples of sea sediment at two points containing ABS only in the upper layer, the average rate of sedimentation of the bottom muds in the inner part of Tokyo Bay since the usage of ABS began was estimated as 3 cm/year and 7 cm/year respectively.     

Mineralogical study of the core samples from the Indian Ocean,with special reference to the vertical distribution of clay minerals

The clay minerals in the 18 core samples collected from the northern, equatorial and southeastern Indian Ocean are illite, chlorite, montmorillonite and kaolinite. In the fraction finer than 2 in the surface layer (top to 5 cm deep) of each core, the relative abundance of clay minerals varies widely from area to area. Kaolinite possesses the maximum proportion of the clay mineral composition and chlorite has the minimum proportion.Kaolinite is particularly dominant in sediments near off the northwestern coast of Australia. In the factions finer and coarser than 2 of the surface layer, montmorillonite and kaolinite tend to be abundant in the fraction finer than 2, and chlorite and illite tend to be abundant in the fraction coarser than 2. In some cores, kaolinite-rich layers in sediments which are considered to have been transported by turbidity currents from the Bay of Bengal are found. Turbidity currents appear partly a role in transport of sediments to the equatorial Indian Ocean.As to the relation between the vertical change of clay mineral composition and geochronological data, montmorillonite and kaolinite tend to be more abundant in interglacial ages than in glacial ages, while illite and chlorite tend to exhibit opposite trend.Muscovite and biotite highly concentrated in the cores Ka-9 and Ka-15 collected from the equatorial Indian Ocean seem to originate from granite or gneiss of Ceylon and/or India.     

Observations of upwelling around the Izu Peninsula,Japan: May 1982

Hydrographic observations between the Izu Peninsula and Oshima Island, Japan, in May 1982, showed upwelling around the tip of the Peninsula and possibly also in the lee of Oshima Island. The upwelling introduced water as cold as 18 C with nitrate concentrations of 3M to the surface. Temperature/salinity analyses indicated that the upwelled water was of Kuroshio characteristics. Slightly fresher water was advected out of Sagami Bay in a coastal counter current.Contribution number 470 from the Shimoda Marine Research Center, University of Tsukuba.     

Ammonium uptake kinetics and interactions between nitrate and ammonium uptake inChattonella antiqua

Ammonium uptake kinetics and interactions between nitrate and ammonium uptake were examined inChattonella antiqua. After the addition of ammonium to the culture ofC. antiqua, the ammonium concentration decreased linearly with time. The ammonium uptake rate as a function of ammonium concentration followed the Michaelis-Menten equation; the maximal uptake rate was 2.0 pmol cell^–1hr^–1 and the half saturation constant, 2.2M. Although the ammonium uptake was not affected by nitrate, uptake of nitrate was rapidly (15min) suppressed by ammonium and a 50% reduction in nitrate uptake was observed at an ammonium concentration ofca. 2M.     

Respiration rates of copepod larvae and a ciliate from a tropical sea

The respiration rates of copepod larvae and a ciliate (Placus sp.) from a tropical sea were measured with an oxygen electrode method. The general range of body size of these animals was 40–161m (diameter equivalent to a sphere), and the respiration rate measured was 0.00076–0.00176l O₂ (animal)^–1h^–1 (or 2.02–9.05l O₂ (mg wet weight)^–1h^–1) at 25.5–29.2C. There was no marked difference observed between the respiration rates of copepod larvae and the ciliate. The respiration rates obtained here are relatively higher than the rates of other similar sized protozoans found in the literature, but lower than the rate extrapolated from larger planktonic copepods in tropical seas.The present results and other information available on microzooplankton biomass suggest that microzooplankton respiration is of near equal importance to that of net zooplankton in the study of energy flow through tropical, pelagic ecosystems.     

Rates of net assimilation and respiration of amino acids by marine bacteria

The selectivity of amino acid assimilation by marine bacteria was examined using seven kinds of¹⁴C-amino acids and the acid hydrolysate of¹⁴C-labelled proteins. It was found that the net assimilation and respiration by marine bacteria followed MICHAELIS-MENTEN kinetics for all of amino acids used in our experiments. Maximum velocities of amino acids were 0.01 to 0.19g carbon/hour per 2×10⁷ cells for net assimilation and less than 0.18g carbon/hour per 2×10⁷ cells for respiration at 20C. The velocity of gross assimilation was found with the following order: phenylalanine>valine, glutamic acid>serine, arginine>tryptophan>glycine. The assimilation velocities of amino acids in these laboratory works showed almost the same order as those in field experiments. The assimilation velocity of an amino acid was influenced by coexisting another amino acids or glucose. The assimilation velocity in lower substrate range of amino acids was directly proportional to the number of bacterial cells in the range from 6×10² to 3×10⁴ cells per ml. No linear relation between the assimilation velocity of amino acids and reciprocal of absolute temperature was found, but a marked bending was observed at 15 to 20C. The velocity at the optimum temperature was three to six times of that at 5C.     

Cobalt content in the shallow sea sediments

Cobalt contained in the sediments from Maizuru Bay and Wakasa Bay was determined by the atomic absorption method. Cobalt content in the surface layer of the bottom sediments averaged 15.2 and 6.7g/g dry matter in Maizuru Bay and in Wakasa Bay, respectively. The vertical distribution of cobalt was almost uniform in the column of bottom sediments. Geographically, the cobalt content in sediments tended to be inverse proportion to the distance from the coast in Wakasa Bay. Considering the distribution of cobalt, it is reasonably concluded that cobalt is not a limiting factor to the production of vitamin B₁₂ by microorganisms in these regions.     

Organic components in size-separated aerosols from the western North Pacific

Marine aerosols in the western North Pacific were collected using a cascade impactor. Size-separated aerosols were analyzed for organic carbon, alkanes and polycyclic aromatic hydrocarbons (PAH). The results showed that the rate of decrease of the atmospheric concentrations of these organic components with increase in distance from Japan as well as from the coast of the Eurasian Continent was in the order PAHalkanes>organic carbon. The bulk of all these organic components occurred in the smallest size fraction of particles (<1m). Analysis of the alkanes and PAH indicated that the hydrocarbons in aerosols in Japanese coastal marine areas are primarily derived from terrestrial anthropogenic sources which also contribute to a lesser extent to aerosols in marine areas about 1,000 km off the coast of Japan. In remote marine areas the hydrocarbons on small particles (<1m) have principally a natural terrestrial origin while those on larger particles are marine in origin.     

Occurrence of coprostanol, 24-ethylcoprostanol and 5α-stanols in the marine sediments

The present study deals with the elucidation of sterol composition of the marine sediments in Kagoshima Bay. The identification of each sterol was performed by gas-liquid chromatography, Ag⁺ impregnated column chromatography, mass spectrometry, and nuclear magnetic resonance spectrometry. The sediment obtained near the estuary of River Koutsuki contained large portions of 5-stanols such as coprostanol and 24-ethylcoprostanol basides 5-stanols such as cholestanol, 24-methylcholestanol, and 24-ethylcholestanol in the sterol fraction. These 5-stanols in the marine sediment may be derived from the fecal contamination by domestic sewages.     

Sterols of the suspended matters in sea water

The present study deals with the content and composition of sterols of the marine-suspended matter in the surface sea water of Kagoshima-Bay. The suspended matters were separated into 3 fractions by filtration with the glass and millipore filters. The sterols in each fraction were analyzed by gas-liquid chromatography on 1.5 % SE-30. The results obtained are as follows: 1) The sterol contents ranged from 2.3 to 20.5g/liter of sea water. 2) Cholesterol was usually present as a predominant sterol in both suspended and dissolved matters. 3) A relatively large amount of other sterols such as 22-dehydro-cholesterol, campesterol, stigmasterol,-sitosterol, and fucosterol were occasionally detected.     

A field study of physico-chemical states of artificial radionuclides in seawater

The physico-chemical states of artificial radionuclides,⁹⁰Sr,¹³⁷Cs and¹⁴⁴Ce in seawater were investigated by radiochemical analysis of filtered and unfiltered seawater. The difference of radionuclide concentrations between unfiltered and filtered seawaters was defined as the particulate form radioisotope and its particle ratio was discussed.Practically no particulate⁹⁰Sr, greater than 0.22 in size, was observed in both coastal and open seawaters, but some of¹³⁷Cs seemed to be insoluble in some circumstances, especially in coastal waters. A considerable amount of¹⁴⁴Ce was found to be particulate.An estimation of the radionuclides in particulate form was made for Kashima-nada seawaters collected in 1970 to 1972, and it was shown that the possible occurrence of particulate radionuclides, greater than 0.22 in size, were 1% or less for⁹⁰Sr and 6% for¹³⁷Cs. In the coastal water, 80 % of¹⁴⁴Ce were seemed to be in particulate form, but in the open seawater only a few%. The influences of suspended materials to¹³⁷Cs and¹⁴⁴Ce concentration levels in seawater were not negligible and further investigations are desirable.     

Accumulation rate and heavy metal pollution in Osaka Bay sediments

The accumulation rates of sediment cores in Osaka Bay have been determined by using²¹⁰Pb dating technique. In the upper 10 cm²¹⁰Pb_ex contents show a constant value with depth. The accumulation rates below the homogeneous layer of sediments ranging from 0.12 to 0.61cm y^–1 (0.067–0.34 g cm^–2 y^–1) were obtained. The higher contents of Zn, Cu, Pb and Cr were observed in the upper 10 to 30 cm of sediments. Assuming that the increment of heavy metal content in sediments is due to anthropogenic origin, the amount of anthropogenic input of heavy metals into sediments were estimated to be 1,300–2,700g cm^–2 for Zn, 150 – 480 for Cu, 360 – 410 for Pb and 320 – 480 for Cr. The increment appears to start about 100 years ago. In surfical sediments most of heavy metal contents exceeded the background content, and then most part of Osaka Bay is polluted by heavy metals.     

Differential sorption of organic matter by various sized sediment particles in recent sediment from the bering sea

A recent unconsolidated marine sediment collected from the Aleutian basin of the Bering Sea (5702.9N, 17657.4W) was separated into eight size fractions by sieving. Each of the fractions was analyzed for density, organic carbon, total nitrogen and various organic materials. A detailed analysis of the correlation of organic carbon and total nitrogen to the mean diameter of the particles separated, indicated that the surface sorption processes of organic matter were the determinative factor controlling the concentration of organic carbon and total nitrogen on silt and clay particles of the sediments.Selective sorption of amino acids was found to occur in the 8–20 and 5–8m. fractions of the sediment. This is assumed to be due to their surface active property.     

Light scattering and suspended particulate matter in the Arctic Ocean north of Ellesmere Island

Light scattering profiles and water samples for filtration of suspended particulate matter were obtained during fall, 1973, from Ice Island T-3, then located about 50 miles north of Ellesmere Island. The profiles reveal almost no variability in scattering, either in the water column, or in time during our two weeks of field work. Gravimetric analysis of the filtered suspended particulate matter shows that mass concentrations are low, averaging about 7g l^–1, and that they too remain very constant. The four water masses present in the Arctic Ocean could not be distinguished by our observations of light scattering and mass concentration of suspended particulates.     

Transport of copper from the Bering Sea to the northwestern North Pacific

Dissolved copper concentrations in surface waters of the Bering Sea ranged from 106 to 882 ngl^–1. Higher concentrations were found in continental shelf waters. In the northwestern North Pacific dissolved copper ranged from 54 to 140 ngl^–1. Particulate copper concentrations varied regionally and seasonally from 6 to 79 ngl^–1. Regionally averaged particulate copper concentrations decreased from 175 to 33g g^–1 against an increase in suspended materials because of the dilution effects of biological fractions. Apparent sporadic increases in copper concentrations were found in the mixing area of the Kuroshio and the Oyashio waters. The feature is attributed to the lateral distribution of different water types rather than to the upwelling of deeper waters by eddies. In the same area west of 160E, waters with high concentrations of dissolved copper (96±9 ngl^–1) were found. Their origin appears to be the continental shelf of the Bering Sea. In spite of intensive biological activity, a considerable fraction of copper added to shelf waters was transported to the area off Japan via the circulation in the Bering Sea and the Oyashio current.     

Deposition Rates of Terrestrial and Marine Organic Carbon in the Osaka Bay, Seto Inland Sea, Japan, Determined Using Carbon and Nitrogen Stable Isotope Ratios in the Sediment

Carbon and nitrogen stable isotope ratios (¹³C and ¹⁵N) of surface sediments were measured within Osaka Bay, in the Seto Inland Sea in Japan, in order to better understand the sedimentation processes operating on both terrestrial and marine organic matter in the Bay. The ¹³C and ¹⁵N of surface sediments in the estuary of the Yodo River were less than –23 and 5 respectively, but increased in the area up to about 10 km from the river mouth. At greater distances they became constant (giving ¹³C of about –20 and ¹⁵N about 6). It can be concluded that large amounts of terrestrial organic matter exist near the mouth of the Yodo River. Stable isotope ratios in the estuary of the Yodo River within 10 km of the river mouth were useful indicators allowing study of the movement of terrestrial organic matter. Deposition rates for total organic carbon (TOC) and total nitrogen (TN) over the whole of the Bay were estimated to be 63,100 ton C/year and 7,590 ton N/year, respectively. The deposition rate of terrestrial organic carbon was estimated to be 13,200 (range 2,000–21,500) ton C/year for the whole of Osaka Bay, and terrestrial organic carbon was estimated to be about 21% (range 3–34) of the TOC deposition rate. The ratio of the deposition rate of terrestrial organic carbon to the rate inflow of riverine TOC and particulate organic carbon (POC) were estimated to be 19% (range 3–31) and 76% (range 12–100), respectively.