巻号一覧
48 巻 (1987)
- 4 号 p. 243-
- 3 号 p. 163-
- 2 号 p. 77-
- 1 号 p. 1-
- Special 号 p. 1-
48 巻, Special 号
選択された号の論文の14件中1～14を表示しています
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大槻 晃, 相崎 守弘, 河合 崇欣1987 年 48 巻 Special 号 p. 1-11
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーSeasonal variations of particulate-phosphorus (PP), dissolved organic phosphorus (DOP), and dissolved reactive phosphorus (RP) concentrations at ten stations in highly eutrophic shallow Lake Kasumigaura were monthly or biweekly monitored during May 1977 to March 1987. Marked increases in total phosphorus concentration at all stations were directly related to the increases in the standing crop of phytoplankton by the blooming of blue- green algae in summer. Under the heavy blooming of the blue-green algae, a clear peak in RP concentration appeared at all stations every summer after 1981. The RP concentrations were 10-20μg·l-1 at lake center and 20-120μg·l-1at the innermost parts of Takahamairi and Tsuchiurairi Bays. The DOP concentrations were nearly constant in the range of 8-25μg·l-1 throughout the years. The linear relationship with a constant between DTP and RP concentrations suggested that DOP might be composed of considerably refractory components.
The characterization of the DOP obtained by reverse osmosis, ultra filtration, and freeze-drying and the DOP production experiments using sample incubations with 32P-phosphate suggested that the DOP in the lake water might mainly originate from phytoplankton and cannot be the substrate for at least bacterial alkaline phosphatase.抄録全体を表示PDF形式でダウンロード (1578K) -
高村 典子, 岩熊 敏夫, 安野 正之1987 年 48 巻 Special 号 p. 13-38
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーThe seasonal succession of phytoplankton was investigated from 1978 to 1985 and the primary production was examined from 1981 to 1985 in Lake Kasumigaura. A large bloom of Microcystis spp. was observed every summer. Synedra rumpens and S. aces dominated in spring, and Melosira granulata, Coscinodiscus tacustris, Cyclotella spp., and/or Chrysochromutina sp. dominated in autumn and winter. Exceptionally large blooms of Closterium aciculare and Oscillatoria agardhii were observed in spring of 1979 and in autumn of 1982, respectively. The gross primary production correlated significantly with the water temperature, the solar radiation, and the chlorophyll a concentration, but not with the nutrient concentrations by multiple regression analysis. Therefore the nutrients were not limiting factors for the primary production in this lake. The annual gross primary production at a center of this lake ranged from 483 to 734 gC·m-2·yr-1, which was intermediate among the values reported in other lakes with Microcystis bloom.抄録全体を表示PDF形式でダウンロード (2549K) -
土谷 岳令, 野原 精一, 岩城 英夫1987 年 48 巻 Special 号 p. 39-44
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーSeasonal patterns of vegetative growth of Trapa natans L. in Takahamairi Bay of Lake Kasumigaura were investigated in 1978, 1979, 1980, 1981 and 1984. Maximum Biomass was approximately 300g dry weight m-2 in normal years, and a proportion of leaf Biomass was as large as 45%. Seasonal patterns of Biomass change were considerably variable among years; only one peak biomass was observed in 1978, 1981 and 1984, while two peaks were noted in 1979 and 1980. Overcrowding of rosettes in early summer due to high spring temperature would be the main reason for the subsequent summer collapses of the biomass observed in 1979 and 1980.抄録全体を表示PDF形式でダウンロード (1003K) -
花里 孝幸, 安野 正之1987 年 48 巻 Special 号 p. 45-57
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーStudies on population dynamics, biomass and production of cladoceran zooplankton in various regions of Lake Kasumigaura were conducted from 1983 to 1985. Seasonal changes in species composition were similar among the regions, but were different among the years. The biomass and production of cladocerans were usually higher in the summer than in the other seasons. Those in the spring and fall were often suppressed by a predator, Neomysis intermedia. Bosmina fatalis, which dominated the cladoceran community in the summer and fall, contributed to the annual biomass and production of the total cladocerans with the highest percentage. The biomass, production and P/B ratio of cladocerans, and the energy transfer efficiency from phytoplankton to zooplankton were higher in Takahamairi Bay and Tsuchiurairi Bay than in the central region of the lake.抄録全体を表示PDF形式でダウンロード (1629K) -
岩熊 敏夫1987 年 48 巻 Special 号 p. 59-75
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーSeasonal changes in the density and biomass of chironomid larvae were studied at 10 locations in Lake Kasumigaura for 4 yr from March 1982-April 1986. Tokunagayusurika akamusi and Chironomus plumosus were dominant at all stations. Clinotanypus sugiyamai was abundant at the centers of Tsuchiurairi and Takahamairi Bays as well as the center of the lake. On the contrary, Procladius culiciformis was distributed mainly at the innermost part of Takahamairi Bay. Larvae of Dicrotendipes sp., Glyptotendipes sp., Microchironomus sp., Polypedilum sp., and Stictochironomus sp. were also recovered from Takahamairi Bay and/or Tsuchiurairi Bay. Density of T. akamusi increased every 2 yr synchronously at all stations except for innermost-bay stations. Although this species emerges every autumn, many of the individuals presumably have 2-yr life cycle. There were three generations per year for C. plumosus, three for C. sugiyamai, and at least two for P. culici formis. C. plumosus density just before the emergence was lower for the summer generation than the winter generation. This was presumably due to the progressive eutrophication of Lake Kasumigaura. Chironomid production was extremely high during the winter. The annual production averaged for 10 stations and for 4 yr was 3.7 g dry weight·m-2·yr-1 for T. akamusi and 3.2 g dry weight·m-2·yr-1 for C. plumosus, 0.052 g dry weight·m-2·yr-1 for C. sugiyamai, and 0.006 g dry weight·m-2·yr-1 for P. culiciformis. Yet the values were underestimated for T. akamusi and C. plumosus. Annual production of both T. akamusi and C. plumosus increased from the innermost part of the bays towards their mouths or the lake outlet.抄録全体を表示PDF形式でダウンロード (2228K) -
相崎 守弘1987 年 48 巻 Special 号 p. 77-84
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーThe long-term variations of aerobic heterotropic bacterial numbers at several sites of Lake Kasumigaura were studied during 1978 to 1986. The numbers fluctuated over a wide range at each station. The ranges of fluctuation were 2.0×1035.0×105 at sites near river mouth regions and 2.0×1024.9×104 cells·ml-1 at sites in the lake center. Seasonal average values of heterotroph numbers showed marked year -to -year changes rather than seasonal changes. These changes were not related to the changes of chlorophyll-a concentration.
Large differences of heterotroph numbers between homogenized and ordinarily treated samples were sometimes observed. In these cases, the numbers of the homogenized samples were about 20100 times larger than that of ordinarily treated samples. It was considered that bacterial aggregates were formed in these cases.
The influence of inflow streams on the variation of heterotroph numbers was surveyed near a river mouth draining into this lake during March to April 1984. The heterotroph number rapidly increased about 20100 times larger than under ordinary conditions soon after rainfall at the sites near the river mouth region. It was made clear that heterotrophs number near a river mouth region was directly affected by inflow streams, especially at the time of rainfall.抄録全体を表示PDF形式でダウンロード (1210K) -
海老瀬 潜一1987 年 48 巻 Special 号 p. 85-97
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーThe long-term variation of particulate matter was mostly governed by the algal content in shallow eutrophic Lake Kasumigaura. However, considering the size composition of particulate matter and the ratios among SS, Chl-a, POC and PON, the differences in their horizontal distributions and seasonal changes became clear quantitatively from the results of the author's analysis. On the basis of the statistics, the particulate matter concentration in Takahamairi Bay, which was the most eutrophic area in the lake, was higher than in Tsuchiurairi Bay, an area influenced by dredging work. When most particulate matter consisted of a particulate size larger than 53μm, Microcystis spp. in the colony state appeared mostly in large quantities for the period from early summer to autumn. The correlation between SS and Chl-a was not high, but those among Chl-a, POC and PON were high. As the particulate matter of smaller size than 20μm included much inorganic matter, the correlations of SS to Chl-a, POC and PON were not always high. The river-mouth area of the lake was the most fluctuating zone of water quality, and there was the distinctive short -term variation of particulate matter by turbid influent river water during flood periods. The concentration of particulate organic matter was high due to the greater primary productivity of algae in the area with the continual supply of nutrients from influent rivers.抄録全体を表示PDF形式でダウンロード (1807K) -
相崎 守弘, 大槻 晃1987 年 48 巻 Special 号 p. 99-106
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーRatios of particulate C, N and chlorophyll-a to particulate P, and ratios of particulate C to N and chlorophyll-a were examined at 10 sites of eutrophic shallow Lake Kasumigaura during 1980 to 1980. The ratios of C/P, N/P and Chl/P abruptly fluctuated at each station throughout the years. The ranges of these ratios were 13129 in C/P, 1.918.9 in N/P, and 0.22.4 in Chl/P. The average ratios increased from the inner part of bays to the central part of the lake. High Chl/P ratios were observed in the range of high N/P ratio and in the range from 40 to 150 μg·l-1 of chlorophyll-a concentration.
The average C/P, N/P and C/N ratios were 3969, 6.510.2 and 6.16.9 at each station, respectively. Only the C/P ratio indicated a moderate P deficiency as an average through the years, especially in the central part of the lake. The C/N ratio frequently exceeded the value of 7.7 in spring and summer seasons. This fact seemed to indicate the presence of a moderate N deficiency in these seasons in this lake.抄録全体を表示PDF形式でダウンロード (926K) -
福島 武彦, 相崎 守弘, 村岡 浩爾1987 年 48 巻 Special 号 p. 107-117
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーDeposition rates were measured by means of sediment traps at five stations in hypertrophic Takahamairi Bay of Lake Kasumigaura for the selected periods of 1981-1986. Separation of deposited fluxes into autochthonous and sediment resuspension components was attempted on the basis of chlorophyll a concentration for the tracer. Even at the central station of the bay, the average daily flux of autochthonous matter was 4g·m-2·d-1 compared with 46g·m-2·d-1 of resuspension. There was a time lag of one or two months between the peak of primary production and that of autochthonous deposited flux, which resulted in a surprising increase in chlorophyll a concentration of lake water in mid-summer. Calculated autochthonous deposited rates of carbon, nitrogen, and phosphorus in backwater regions and near the inflow river mouth were much higher than those at offshore due to the contamination of allochthonous matter. In regard to the resuspension rates, a logarithmic decrease against water depth and significant correlations with some meteorological conditions were observed. The sum of autochthonous and allochthonous deposited fluxes exceeded the accumulation rates in sediments estimated both by the mass balance method and the sediment dating method by a factor of 8-17 for nitrogen and 2-10 for phosphorus, both of which were much larger than the ratios observed in other lakes. The shallowness of this lake greatly influenced these ratios because of the large resuspension rate followed by rapid decomposition in lake water and high activity of benthos.抄録全体を表示PDF形式でダウンロード (1607K) -
細見 正明, 須藤 隆一1987 年 48 巻 Special 号 p. 119-129
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーNutrient concentrations in interstitial water of the surface sediments in Lake Kasumigaura have been analyzed and their seasonal variations and vertical distributions observed during a six-year period at three stations. Interstitial water was obtained using the centrifugation-filtration method. NH4-N concentration in interstitial water in the surface sediments changed seasonably. NOx-N concentration in interstitial water could be observed only in the surface sediment (0-2cm) from autumn to early spring. Nitrogen flux at the sediment-water interface was estimated by a mathematical model based on Fick's law. Maximum NH4-N release flux was observed during the summer and early autumn, and was found to decrease with a decrease in water temperature. NOx-N fluxes from water to sediment decreased gradually from the mouth of the river entering Takahamairi Bay toward the center of Lake Kasumigaura. Maximum gradient of the PO4-P concentration in the water-sediment interface was observed during summer and early autumn.抄録全体を表示PDF形式でダウンロード (1579K) -
大坪 国順, 村岡 浩爾1987 年 48 巻 Special 号 p. 131-138
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーThe vertical profiles of physical parameters of bottom sediment, such as water content, specific gravity of grain, and ignition loss and their seasonal changes are discussed for the samples taken from three representative sites in Lake Kasumigaura. The results of field research as to sediment resuspension in the lake are shown here as well. All physical parameters showed vertical changes and differences due to the sampling site; however, no seasonal change or long-term tendency was recognized for any sample. The water wave induced by wind was found to be the main cause of bottom sediment erosion in Takahamairi Bay of Lake Kasumigaura. Near the field research site, bottom sediment began to be resuspended when wind velocity exceeded 6 m.s-1, and the turbidity reached 200300 mg·l-1 when wind velocity exceeded 12m·s-1.抄録全体を表示PDF形式でダウンロード (1124K) -
高村 典子, 渡辺 信1987 年 48 巻 Special 号 p. 139-144
発行日: 1987/12/30
公開日: 2009/11/13
ジャーナル フリーSeasonal changes in the biomass of Microcystis species were investigated during 1982-1985 in Lake Kasumigaura, Japan. Microcystis in this lake was composed of four formas and species, i.e., M. aeruginosa f. aeruginosa, M. aeruginosa f. flos-aquae, M. viridis and M. wesenbergii. These taxa almost always appeared as a mixed population. The dominant species did not vary largely, station by station, but changed remarkably year by year. M. aeruginosa f. aeruginosa and M. aeruginosa f. flos-aquae tended to predominate in the early stage of the bloom or throughout the bloom, while M. viridis did so in the middle and late stages of the bloom. M. wesenbergii did not appear with a definite tendency. An over wintering population in the water was composed of M. aeruginosa f. aeruginosa and M. viridis. The importance of studies on Microcystis at the species level was discussed.抄録全体を表示PDF形式でダウンロード (669K) -
1987 年 48 巻 Special 号 p. e1
発行日: 1987年
公開日: 2009/11/13
ジャーナル フリーPDF形式でダウンロード (17K) -
1987 年 48 巻 Special 号 p. e2
発行日: 1987年
公開日: 2009/11/13
ジャーナル フリーPDF形式でダウンロード (20K)
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