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Volume 46, Issue 3
Displaying 1-9 of 9 articles from this issue
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Morihiro AIZAKI1985 Volume 46 Issue 3 Pages 159-168
Published: July 30, 1985
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSRemoval and excretion activities of dissolved organic substances by periphyton communities were examined using artificial substrata submerged in the water of the eutrophic River Tamagawa and laboratory recirculating streams. These activities changed with the progress of biofilm development. High removal activity of dissolved organic substances was observed in the early stage of the biofilm development, while high excretion rate was found in the mature stage. A maximum exertion rate was 580 mgC·m-2·d-1. Organic substances removed from the water were biologically labile compounds which can be determined by BOD, and excreted organic substances were regarded as microbiologically stable compounds. Decomposition products formed at the inside of periphyton biofilm were considered to be an important source as well as photosynthetic products by sessile algae for the excretion of organic substances from the periphyton community in the mature stage of biofilm development.View full abstractDownload PDF (1417K) -
Masaya MIYAI, Fumi TADA, Hideo NISHIDA1985 Volume 46 Issue 3 Pages 169-173
Published: July 30, 1985
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThis report describes an application of principal component analysis to heavy metal contents (Cu, Cr, Zn, Pb, Cd, Ni), HNO3-H2O2 soluble metals in the upstream sediments and 0.5 N HCl soluble ones in the downstream sediments. Two principal factors were extracted, and a comparison was made between the distribution of heavy metals on the plane produced by two factor loadings and that of rivers on the plane produced by two factor scores.
Results show that the first factor represents the general pollution by heavy metals. The second factor in HNO3-H2O2 soluble heavy metals in the upstream sediments represents an axis of siderophile-chalcophile element from the standpoint of geochemistry, while the second factor in 0.5 N HCl soluble heavy metals in the downstream sediments represents an axis of adsorbable-unadsorbable element in sediment from the standpoint of artificial heavy metal pollution.View full abstractDownload PDF (709K) -
Dispersion Coefficients in Naka River and Kiki River Estuaries and Scale EffectTadao KAKINUMA, Yosuke KISHI, Kunimitsu INOUCHI, Katsuaki TSUZUKI1985 Volume 46 Issue 3 Pages 174-184
Published: July 30, 1985
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSA three-dimensional steady state model involving the effect of dispersion is used to stimulate seawater encroachment in the confined aquifers in the estuaries of the Naka River, Tokushima Prefecture, and the Kiki River, Ehime Prefecture. The magnitudes of the dispersion coefficients in the above two regions together with those in other experimental and observational studies are reviewed from the viewpoint of the scale effect.
The main results are as follows : 1) The horizontal and vertical dispersion coefficients are 5 cm2·sec-1 and 5 to 0.5 cm2·sec-1 in the estuary of the Naka River, respectively. In the estuary of the Kiki River, the corresponding values are 0.2 cm2·sec-1 and 0.2 to 0.02 cm2·sec-1, respectively. 2) The groundwater level predicted with the dispersion model is almost the same as the one with the interface model (KAKINUMA et al., 1984) and about 1.3 times the observed one. 3) The ratio of the dispersion coefficient to the hydraulic conductivity is proportional to the thickness of the aquifer. This result is consistent with the one given by the hydraulic similitude.View full abstractDownload PDF (1579K) -
Takayuki HANAZATO, Masayuki YASUNO1985 Volume 46 Issue 3 Pages 185-191
Published: July 30, 1985
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSEffect of temperature on growth, egg development and age at first parturition of five cladoceran species (Daphnia longispina, Moina micrura, Diaphanosoma brachyurum, Bosmina longirostris and Bosmina fatalis) were investigated in the laboratory. The relationships between egg development time of these species and temperature, and between age at first parturition and temperature, were expressed by an equation (ln D=ln a+b (ln T) 2). M. micrura and Diaphanosoma brachyurum seemed to have adapted to relatively higher temperature, while Daphnia longispina, B. longirostris and B. fatalis showed their adaptation to lower temperature. However, the results did not necessarily agree with the seasonal succession of the appearance of these species in the field.View full abstractDownload PDF (1057K) -
Michiro MATSUYAMA1985 Volume 46 Issue 3 Pages 192-198
Published: July 30, 1985
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSA gas-vacuolate phototrophic bacterium was isolated from the bacterial plate at the mid-depth of Lake Kaiike using the medium of PFENNIG (1965) The bacterium was ovoid to short-rod (3 to 5 by 4 to 8 μm) in shape, and buoyant when it contained gas vacuoles. It formed a violet suspension and a pinkish flotation on the top of the medium, and at depletion of H2S entered the stationary phase. Gas vacuoles were easily collapsed when the bacterial suspension was centrifuged (1000 g, 15 min.). The bacterium was motile and similar to Lamprocystis roseopersicina. In early November 1984, this bacterium was predominant in the bacterial plate. At the same time, a considerable amount of irregular-shaped violet slime composed of the bacterium covered the entire surface of the lake.View full abstractDownload PDF (1304K) -
Tomiko ITO1985 Volume 46 Issue 3 Pages 199-211
Published: July 30, 1985
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSThe female, pupa, larva and egg of Goerodes naraensis (TANI, 1971) are described together with the geographical variation in the adult features. The habitat, food, case and annual life cycle are also reported.
Morphology of the adult varies in different localities, and four local types are distinguished in Japan. The head length and first segment length of antenna of both sexes decrease from southwestern to northeastern localities. The paramere and clasper of male genitalia in southwestern Japan are more protrusive and complex than those in northeastern Japan.
The larvae live in mountain brooks and generally feed on allochthonous dead leaves. The larvae make their cylindrical cases of sand grains from first to fourth instar and four-sided cases of leaf pieces at fifth instar. This species has a univoltine life cycle in Sapporo, northern Japan; larvae of the new generation appear in midsummer, develop in autumn, overwinter at fifth instar, and pupate and emerge in late spring.View full abstractDownload PDF (1482K) -
Takayuki HANAZATO, Masayuki YASUNO1985 Volume 46 Issue 3 Pages 212-214
Published: July 30, 1985
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (427K) -
Hidenobu KUNII, Takayoshi TSUCHIYA, Kiyoshi MATSUI, Isao IKUSIMA1985 Volume 46 Issue 3 Pages 215-218
Published: July 30, 1985
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSInvestigation of the floristic composition of aquatic plants (except for emergent plants) in Lake Biwa and 17 selected surrounding water bodies was done from shore in 1982. A total of 22 and 13 species were found in Lake Biwa and in the surrounding water bodies, respectively. The species found with a high frequency were Elodea nuttallii (Planch.) St. John, Egeria densa Planch. and Vallisneria biwaensis (Miki) Ohwi in Lake Biwa, and E. nuttallii, Trapa spp. and Spirodela polyrhiza (Linn.) Schleid. with Lemna sp. in the surrounding water bodies. Average number of species found in a surrounding water body was 2.9 in summer 1982, mostly including an alien plant, E. nuttallii (about 75% frequency).View full abstractDownload PDF (422K) -
Kazumi TANIDA, Kohichi YAMASHITA, Andrew ROSSITER1985 Volume 46 Issue 3 Pages 219-221
Published: July 30, 1985
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSA portable current meter for accurate current speed measurement and suitable for use by an individual in natural streams was devised. The meter consists of a sensor with a four-bladed propeller (30 mm diameter), a photo coupler and a counting apparatus (a modification of the 3631 rotation meter : Yokogawa Hokushin Electric). A high accuracy of calibrations was obtained under laboratory conditions, and its reliability and operability were also tested at a natural stream.View full abstractDownload PDF (432K)
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