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Volume 53, Issue 4
Displaying 1-15 of 15 articles from this issue
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Hirohisa KATO, Norio OGURA1992 Volume 53 Issue 4 Pages 265-272
Published: October 29, 1992
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSThe water quality of ground waters (spring and deep-well waters) in the Kitatama area of Tokyo was studied once a week during the two-year period 1986-1988. Nitrate nitrogen concentrations in spring water at station N-0 along Kokubunji Cliff ranged from 467 to 653μgat⋅l-1, with high concentrations in winter and low in summer. The secular change of spring water at N-0 during the 13 year period 1976-1988 showed that discharge and chloride ions concentrations tended to decrease, while nitrate nitrogen concentrations tended to increase gradually. In spring waters along Kokubunji Cliff, nitrate nitrogen concentrations showed high values over 800μgat⋅l-1. Nitrate nitrogen concentrations in two deep-well waters were lower (W-1: 353-609μgat⋅l-1, W-2: 143-253μgat⋅l-1) than those in spring water (shallow ground water) along Kokubunji Cliff.View full abstractDownload PDF (392K) -
Tadafumi ICHIKAWA, Takahito YOSHIOKA, Eitaro WADA, Hidetake HAYASHI1992 Volume 53 Issue 4 Pages 273-280
Published: October 29, 1992
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSThe uptake rate of nitrogen by freshwater zooplankton was measured by use of a 15N tracer technique under experimental conditions. To detect the low quantities of excess 15N in less than several hundreds of small zooplankton individuals (as small as 5 μgN), an isotope dilution technique was adopted using a ratio mass spectrometer. The analytical differences between natural 15N abundance method and result obtained by this technique were -0.00210 to +0.00113 15N atom % (mean±S.D.=0.00048±0.0010 15N atom %) . We obtained uptake rates of 8.5×10-8mg atom-N⋅indiv.-1⋅day-1 by Kellicottia longispina in Lake Nakatsuna and 4.2×10-7 by Keratella quadrata in Lake Suwa. Net production rates calculated from the data of the uptake rates, carbon contents and nitrogen contents were 5.1×10-6 mgC⋅indiv.-1⋅day-1 for K. longispina and 2.5×10-5 mgC⋅indiv.-1⋅day-1 for K. quadrata. Using a combination of the ratio mass spectrometer and the 15N tracer experiment, the nitrogen uptake rates from nutrient salt to phytoplankton and further to zooplankton can be detected directly at the same time and on the same space scale.View full abstractDownload PDF (444K) -
Yudhi Soetrisno GARNO, Mitsuru SAKAMOTO1992 Volume 53 Issue 4 Pages 281-292
Published: October 29, 1992
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSExperimental studies using four enclosures each containing pond waters of 2.9 m3 in volume were performed to analyse the effects of nutrients and zooplankton on succession of the phytoplankton community. Nutrient enrichment at the beginning of the experiment produced marked increases in chlorophyll-a concentration and algal cell density, followed by a sharp decrease in algal abundance in the later half of the experiment. Three patterns of algal population growth (Types I, II and III) were observed under a regime of decreasing nutrient concentrations. Population development of Simocephalus vetulus (cladocera), which were added to the enclosures accelerated declines in the algae of Types I and II. Species-specific differences in algal nutrient utilization efficiency and a considerable decrease in nutrient concentrations caused by phytoplankton growth were major factors in determining successional changes in phytoklankton of the three growth types.View full abstractDownload PDF (720K) -
Hitoshi UEMURA, Ryoshi ISHIWATARI1992 Volume 53 Issue 4 Pages 293-303
Published: October 29, 1992
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSAliphatic hydrocarbons and hopanoid hydrocarbons were analyzed in a short (16 cm) sediment core sample from Lake Haruna, and their short-term variations were investigated.
The carbon preference index of n-C25-C33 alkanes in the core decreases from 6.0-7.7 at depths of 7-16 cm to 2.2 in the surface (0-1 cm) sediment. UCM (unresolved complex mixture: hump on a gas chromatogram) increases from the bottom sections to surface sediment, maximizing at depths of 3-4 cm. The vertical profile of UCM coincides well with that of 17α(H), 21β(H) hopanes. These vertical profiles indicate that oil pollution in Lake Haruna started in the 1940's (6-7 cm in depth) reaching its maximum between 1969-1976 (3-4 cm in depth). C31 17α(H), 21β(H) hopane proved to be the best indicator of oil pollution in sediment.View full abstractDownload PDF (585K) -
Keiji USUI, Toshio HIGASHI1992 Volume 53 Issue 4 Pages 305-315
Published: October 29, 1992
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDammed up lake Ono is located in the northeast part of Ube-shi, Yamaguchi Prefecture. Since limestone comprises part of drainage basin of rivers flowing into the lake, the Ca concentration of the lake water is comparatively high (20-25 mg⋅l-1), though still beneath the level of hard water.
Although a high saturation index of CaCO3 (calcite) was confirmed in the epilim-nion of the lake, no precipitation was detected.
A laboratory test, however, demonstrated that addition of a few seed crystals of calcite (8-9 μm in diameter) to the lake water adjusted the temperature and pH to summer conditions (25°C, pH 9.12). This warming, together with addition of NaOH induced precipitation of CaCO3 along with phosphate, thus eliminating about 20% of Ca ions in the lake water. This phenomenon was not observed when pH was adjusted by decarbonization.View full abstractDownload PDF (551K) -
Yasuhiro SATOH, Masahiro OCHIAI, Tomokazu OYAMA, Naoki KOIDE1992 Volume 53 Issue 4 Pages 317-326
Published: October 29, 1992
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSThe concentration of dissolved carbohydrate (DCHO) in water of a mountain bog pool was determined by three different methods from May to November, 1990. The phenol sulfuric acid (PSA) method consistently gave the highest concentration (1.22-4.01, average 2.15 mgC⋅l-1). The concentration of DCHO by the 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) method ranged 0.75-2.18 mgC⋅l-1 (average, 1.36 mgC⋅l-1). The ratio of MBTH-DCHO/DOC indicates that DCHO constituted a rather constant fraction of the DOC pool. Eight neutral monosaccharides were determined by gas chromatography (GC). GC-DCHO (sum of the 8 saccharides) ranged 0.28-1.99 mgC⋅l-1 (average, 0.99 mgC⋅-1). Glucose (25%), galactose (22%) and mannose (15%) were dominant. GC-DCHO agreed well with MBTH-DCHO from late May to early August, and was smaller than MBTH-DCHO in autumn.
Based on the specificity of the colorimetries given by previous authors, we adopted the results from the MBTH method as a measure of the total DCHO pool size. From these results, the PSA method appears to have overestimated the DCHO in bog water. On the other hand, to clarify the composition of DCHO is of great advantage to the GC method, though the method requires time, and its application is limited to the neutral sugars.View full abstractDownload PDF (538K) -
Shigehisa HATAKEYAMA, Satoshi FUKUSHIMA, Fumie KASAI, Hiroaki SHIRAISH ...1992 Volume 53 Issue 4 Pages 327-340
Published: October 29, 1992
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSEffects of overall herbicide toxicity on primary production were investigated by an algal growth test using Selenastrum capricornutum (Chlorophyceae) with water samples collected from a sampling station in the R. Kokai from April to August, 1991. Bacteria were eliminated from the water samples before the test, and extra N (33 mg⋅l-1) and P (5.38 mg⋅l-1) were added. The concentrations of 8 kinds of herbicide were analysed simultaneously. Growth of Selenastrum was inhibited significantly in the water samples from early May to late June by several of the herbicides. The most serious inhibition in mid-May was attributed to the joint toxicity of butachlor and pretilachlor. The sequential growth inhibition from the end of May to late June was attributed mostly to simetryn, although combined effects of several other herbicides were slightly recognizable at the end of May.
Periphyton which formed on the artificial substrates was also affected, judging from the number of species as well as the rate of accumulation, possibly by several kinds of herbicide from mid-May to mid-June, when the growth of Selenastrum was inhibited in the river water samples. These results suggest that algal production in rivers may be affected by herbicides at least in the period from May to June.View full abstractDownload PDF (891K) -
Decomposing processes of grass carp feces under aerobic laboratory conditionsKatsuya IWATA, Noriko TAKAMURA, Jia-Le LI, Xue-Bao ZHU, Taizou MIURA1992 Volume 53 Issue 4 Pages 341-354
Published: October 29, 1992
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSIn a Chinese integrated fish culture conducting around Dianshan Lake in Shanghai, Grass carp (Ctenopharyngodon idella) and some other cyprinid fishes with different food habits are coreared with water plants to give extremely high fish yields. In this system, a large amounts of grass carp excreta suspended in the culture pond seem to play an important role in providing food material directly or indirectly to other fishes. In fact, considerable quantities of decomposing grass carp feces were found in the intestinal contents of Carassius auratus and Aristichthys nobilis.
In the present study, grass carp feces (fragments of Vallisneria spiralis) collected from the pond were decomposed under aerobic laboratory condition, in order to discover the role of grass carp feces in the food-webs of this pond ecosystem.
During 16 days of decomposition, carbon contents in the feces decreased at a constant rate to 50% of original contents, while nitrogen contents hardly decreased for the first 8 day periods of the experiment. The nitrogen as well as amino acid contents per unit of dry weight of feces increased up to the maximum level on the 8th day of the experiment, but changed little during further decomposition. 15NH4+ and 3H-thymidine added the incubation medium were actively incorporated into various sized fecal fragments. It is suggested that decomposing grass carp feces (including resultant bacteria and their metabolic products) make a new food resource available to invertebrates as well as to the plankton and benthos cyprinid feeders in this pond ecosystem.View full abstractDownload PDF (3802K) -
Possibility of Calcite Formation in Lake WaterHaruo FUKUHARA, Noriko AOYAGI, Yuko SAITOH, Osamu SATO1992 Volume 53 Issue 4 Pages 355-361
Published: October 29, 1992
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSStrong summer calcium stratification in the water of harmonic type Lake Takanamiike (Itoigawa, Niigata), with a moderately high calcium concentration averaging 18.7 mg⋅l-1 annually was observed first by the authors. The average concentration in the epilimnion was 16.6 mg⋅l-1 and 20.4 mg⋅l-1 in the metalimnion in August, 1990. Supersaturation concerning calcite apparently occured in the epilimnion from June to August when a high pH value above 8 and high water temperature were obtained. Calcium stratification, calcite supersaturation and changes in calcium concentration and alkalinity suggest the possibility of calcite formation in these water layers owing to primary production.View full abstractDownload PDF (406K) -
Kenzi TAKAMURA1992 Volume 53 Issue 4 Pages 363-372
Published: October 29, 1992
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSTwo species of chironomids Cricotopus tamapullus and Paratrichocladius rufiventris predominantly emerged from six outdoor artificial channels, first four, and then three of which were exposed to ABS. Chironomid emergence was decreased by exposure at about 2.7 ppm average concentrations for one month, but showed no decrease at concentrations of about 1 ppm or lower for three months. The results suggested that the decrease in chironomid emergence was attributable to negative effects of ABS at the time of emergence or at aquatic life stages. The latter possibility was suggested as a secondary effect by the fact that attached algae were decreased by exposure at 2.7 ppm.View full abstractDownload PDF (508K) -
Takeshi MATUBARA1992 Volume 53 Issue 4 Pages 373-377
Published: October 29, 1992
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSThe esophageal and gizzard contents of wintering Northern Shovelers (Anas clypeata) in the hypertrophic Lake Teganuma were analyzed to ascertain their feeding habits. Seven ducks were captured in March 1991 using a Japanese traditional hunting method (Nagashi-mochi-nawa). Their esophageal and gizzard contents were removed immediately, fixed with formalin and observed under a microscope. No identifiable contents were found. However, the major contents of the gizzard were cyclopoid copepodids and an attached green alga Cladophora glanurata, plus an insignificant number of rotifers Brachionus calyciflorus, B. leydigii, B. angularis, Trichocerca birostris and Polyarthra spp., as well as nematodes Nematoda spp. and attached diatoms Navicula spp. and Synedra spp..View full abstractDownload PDF (1565K) -
Raoul HENRY1992 Volume 53 Issue 4 Pages 379-384
Published: October 29, 1992
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSOxygen actual and relative deficits in Jurumirim Reservoir were computed from the temperature and dissolved oxygen profiles determined in a study from March 1988 to March 1989. The reservoir presented an isothermy from June to September and a thermal stratification from October to March. Thermocline was always located at the 1/3 deeper zone of the-water column. Clinograde oxygen profiles were observed during the thermal stratification period. Water in the reservoir was always well oxygenated until 20 m depth along the year. At the bottom (25 m depth), O2 content decreased significantly during the thermal stratification period. Thus, the deficits were higher at the bottom. Total oxygen actual and relative deficits for all the reservoir ranged from 0.03 to 0.72 mg⋅cm-2 and from 0.013 to 0.032 mg⋅cm-2⋅day-1, respectively. Using other trophic status indices such as Secchi disk transparency and chlorophyll-a concentration as well as the oxygen deficits, Jurumirim Reservoir can be categorized in the oligotrophic class.View full abstractDownload PDF (300K) -
Michiyori KOBAYASHI1992 Volume 53 Issue 4 Pages 385-394
Published: October 29, 1992
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSThe concentration of Hb in Daphnia magna hemolymph is inversely related to the O2 concentration of its aquatic habitat. Under low oxygen conditions, immature animals are most capable of Hb synthesis. Hb-rich animals can swim a longer distance even in very low O2 concentration in which Hb-poor animals are able to swim only a short distance. Daphnia magna is an O2 regulator, and Hb-rich animals have a lower critical O2 concentration than that of Hb-poor animals. The fifty per cent of in vivo oxygenation of Hb is found at 15 and 35 torr for Hb-rich and Hb-poor animals, respectively.
The purified Hb from Hb-rich animals has a higher O2 affinity than that from Hbpoor animals. Hemoglobin is separated into at least six components by isoelectric focusing. Hemoglobin solution from Hb-rich animals has a different proportion of the Hb component from that of Hb-poor animals, and the increase in O2 affinity is concomitant with an increase in the relative amounts of Hb components of high isoelectric point. This suggests that Daphnia magna may adapt to a wide range of environmental O2 conditions by means of multiple Hb.View full abstractDownload PDF (660K) -
1992 Volume 53 Issue 4 Pages 395
Published: October 29, 1992
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSDownload PDF (49K) -
1992 Volume 53 Issue 4 Pages 395a
Published: 1992
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESSDownload PDF (23K)
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