巻号一覧
49 巻 (1988)
- 4 号 p. 227-
- 3 号 p. 149-
- 2 号 p. 71-
- 1 号 p. 1-
49 巻, 3 号
選択された号の論文の7件中1～7を表示しています
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八木 明彦1988 年 49 巻 3 号 p. 149-156
発行日: 1988/07/30
公開日: 2009/11/13
ジャーナル フリーVertical profiles of dissolved manganese were measured in the anoxic hypolimnion of Lake Fukami-ike, from May to June 1987. The dissolved manganese in the hypolimnion water was specified by ultrafiltration and by XAD-2 resin. Percentages of dissolved manganese in four molecular weight fractions were 21 to 75% (M.W. <1, 000), 25 to 55% (M.W. 1, 000-50, 000). 2 to 7% (M.W. 50, 000-200, 000) and 3 to 30% (M.W. > 200, 000), respectively. The amounts of dissolved manganese adsorbed by XAD-2 resin at neutral pH were nearly equal to those measured by ultrafiltration in the latter three high molecular weight fractions. These results indicate that about 40% of total dissolved manganese was present as organic forms, mainly having a molecular weight of 1, 000 to 50, 000, in the hypolimnion of Lake Fukami ike.抄録全体を表示PDF形式でダウンロード (866K) -
平地に分布する黄褐色の水色の溜池の付着珪藻相の特徴村上 哲生, 近藤 繁生, 松井 義雄1988 年 49 巻 3 号 p. 157-166
発行日: 1988/07/30
公開日: 2009/11/13
ジャーナル フリーWater quality and the flora of epiphytic diatoms on reed stems in 50 eutrophic irrigation reservoirs distributed in the lowland near Nagoya City were investigated. There are some reservoirs with yellowish brown colored water characterized by low pH, low Ca ion concentration and high COD/BOD ratio. The UV spectrum of the colored water resembled to that of the fulvic acid. As for the species composition of the epiphytic diatom community, acidophilus or sphagnophilous Eunotia and Pinnularia were abundant. Based on the water quality and the diatom flora, it can be concluded that the reservoirs with yellowish brown water distributed in the lowland belong to dystrophic lake type.抄録全体を表示PDF形式でダウンロード (1963K) -
永田 俊1988 年 49 巻 3 号 p. 167-174
発行日: 1988/07/30
公開日: 2010/11/22
ジャーナル フリーSeasonal abundance of heterotrophic microflagellates and bacteria was investigated at an offshore station (water depth, ca. 4 m) in the south basin of Lake Biwa (eutrophic water basin) during May to October 1984. Cell abundance of flagellates and bacteria ranged from 1.7×103 to 9.7×103 cells·ml-1 and 2.5×106 to 1.5×107 cells·ml-1, respectively. The instantaneous grazing rate (g) of flagellates on bacteria was estimated from the total cell volume of flagellates and the volume specific clearance rate of flagellates reported in the literature. The g values ranged from 0.003 to 0.020 h-1. The instantaneous growth rate (μ) of bacteria estimated from the frequency of dividing cells method ranged from 0.009 to 0.034 h-1. From the values of g and μ, it was estimated that 13-130% of bacterial daily production was consumed by flagellates. Vertical distribution of flagellates at the dredged area (water depth, ca. 12 m) of the same water basin revealed that flagellates reached maximum abundance in a subsurface layer (6 m-depth) during the stratification. The significance of flagellates as bacterial consumers and some characteristics of their occurrence in the eutrophic water body are discussed.抄録全体を表示PDF形式でダウンロード (962K) -
中西 正己, 成田 哲也, 鈴木 紀雄, 三田村 緒佐武1988 年 49 巻 3 号 p. 175-183
発行日: 1988/07/30
公開日: 2009/11/13
ジャーナル フリーSeasonal changes in assimilation numbers and daily primary production rates of total phytoplankton and nannoplankton were studied in connection with some environmental variables at littoral and pelagic sites in the south basin of Lake Biwa. The assimilation number was not so different with seasonal variation between both sites and within the range of 0.2-5.8 mg C·mg Chl.a-1·hr-1. As a result of multiple regression analysis, water temperature proved to be the most significant contributor in the variation of assimilation numbers of the total and nannoplankton at any site, accounting for 59-73%, while DIN and DIP were not significant. The daily gross primary production rate of the total phytoplankton also was not so very different with seasonal change between both sites, ranging from 0.07 in January to 1.93-2.74 g C·m-2·d-1 in late August or early September. Nannoplankton contribution to the total daily production rate was very high, averaging 77% during January-July with relatively high DIN stock, against a low 39% of the total during August-December, with low DIN stock mostly below 1μg at. N·l-1.抄録全体を表示PDF形式でダウンロード (1083K) -
熊谷 道夫1988 年 49 巻 3 号 p. 185-200
発行日: 1988/07/30
公開日: 2009/11/13
ジャーナル フリーTo estimate the time change of resuspended sediment concentration in a lake, a field observation was carried out at the platform in the Northern Basin of Lake Biwa, and a predictive model, containing effects of both wind waves and currents induced by wind, was constructed. In this model, two layers were considered : one, the lower layer, referred to the bottom turbid layer, and the other, the upper layer, above the lower layer. The bottom turbid layer was defined as the region where an acceleration term is balanced with a stress term.
The prediction was applied to the field data, and the predicted values were compared with the observed ones. It was found that the unsteady solution yields better agreement with the field data than the steady solution. The depth of erosion was also estimated to be less than 0.2 cm. With the optimization method, the drag coefficient (Cd) and the parameter (γ) concerned with suspended sediment concentration in the bottom turbid layer were estimated, and the values of 0.71.2×10-3 for Cd and 0.33.9×10-3 for γ were obtained. The correlation coefficient between the predicted values and the observed values was 0.83.抄録全体を表示PDF形式でダウンロード (2087K) -
手塚 泰彦1988 年 49 巻 3 号 p. 201-204
発行日: 1988/07/30
公開日: 2009/11/13
ジャーナル フリーIn the summer of 1986, the depletion of dissolved inorganic nitrogen (DIN) in the lake water persisted for about two months from mid August to early October in the south basin of Lake Biwa. An Anabaena bloom appeared about a half month later from the onset of this DIN depletion and persisted for about one month. During the period of Anabaena bloom, both total and particulate phosphorus concentrations were much higher than in the preceding period. Thus, it was suggested that, in addition to the DIN depletion, phosphorus supply to the lake water from somewhere stimulated the massive growth of Anabaena.抄録全体を表示PDF形式でダウンロード (419K) -
中島 淳, 金子 光美1988 年 49 巻 3 号 p. 205-212
発行日: 1988/07/30
公開日: 2009/11/13
ジャーナル フリーTotal P, oraganic P and fractionated inorganic P were determined in a core sample of 130cm depth collected from Lake Suwa. Total P, aluminum P and iron P were enriched in the surface sediment. Organic P in the core sample ranged from 0.18 to 0.39 mg·g-1 and its percentage to total P ranged from 12.3 to 18.8%. The change of oraganic P with the core depth was closely related to that of organic C. Organic P was fractionated into three fractions through a column of Sephadex G-75. In the surface sediment the percentages of organic P in G-75-I (MW>50, 000), G-75-II (MW=1, 00050, 000) and G-75-III (MW<1, 000) were 32.9, 38.7 and 28.4%, respectively. The amount of organic P decreased with the core depth in G-75-II and G-75-III, while it was unchanged in G-75-I. Organic P was separated into humic acid and fulvic acid fractions and the molecular weight distributions of the fractions were determined. It was suggested that organic P in lake sediments was stable in the high molecular weight fraction.抄録全体を表示PDF形式でダウンロード (1076K)
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