巻号一覧
39 巻 (1978)
- 4 号 p. 147-
- 3 号 p. 97-
- 2 号 p. 49-
- 1 号 p. 1-
39 巻, 4 号
選択された号の論文の6件中1～6を表示しています
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斉藤 昭二1978 年 39 巻 4 号 p. 147-155
発行日: 1978/10/30
公開日: 2009/10/21
ジャーナル フリーSeasonal succession of phytoplankton was investigated for five years (1973-1977) in Sagami Reservoir. Surface waters were sampled once or twice a week at the station close to the outlet. Chlorophyll a content was less than 10 mg/m3 during the winter, and showed many high peaks successively from April to October. Rapid recovery of dissolved silica concentration was observed after the decline of diatom populations. It is suggested that such a rapid recovery is due to the rapid supply of dissolved silica from the hypolimnion through which a large volume of inflow-water rich in nutrients (1/13.5 per day of the effective storage capacity) passes. In the same way other nutrients are assumed to be supplied rapidly. Thus, these conditions may be explain the appearance of many peaks of chlorophyll a.
The first peak of chlorophyll a corresponded to the increase of Cryptomonas sp.. Spring outburst of diatoms occurred in late April, and seven principal diatoms increased successively until late June. It is suggested that the main factor in the outburst is a decrease in the rate of diatom loss from the epilimnion due to the change in the flow rate of the river water. Growth of blue-green algae was influenced frequently by flooding in summer, while blooms of blue-green algae were observed until mid October in years without a flood. In the autumn Cyclotella sp. were usually predominant. Seasonal succession of phytoplankton in Sagami Reservoir was heavily influenced by the inflow of a large volume of eutrophic river-water.抄録全体を表示PDF形式でダウンロード (1123K) -
渡辺 仁治, 大柳 実喜子1978 年 39 巻 4 号 p. 156-162
発行日: 1978/10/30
公開日: 2009/10/21
ジャーナル フリーA limnological study of an inorganic acid crater lake, “Fudo-ike” in Kirishima National Park was carried out at four sampling stations in the latter part of October and November, 1975 (Fig. 1). In this lake the pH value of the water has become higher during the past forty years and a few zooplankton species seem to have occured. Epilithic, epipelic and epiphytic diatom communities were studied from the taxonomical and ecological viewpoint.
Thirty four taxa including 10 genera were enumerated in the present study (Table 3). Morishita's indices of similarity between their diatom communities were calculated by using the relative frequencies of all diatom taxa observed at each station (Table 4). The results were shown in Table 5 as matrix. As a result of cluster analysis based on the matrix of similarities obtained all diatom communities can be divided into three groups (Table 6).抄録全体を表示PDF形式でダウンロード (844K) -
Growth and Detachment of Periphyton in an Effluent from the Secondary Treatment Plant of Wastewaters大竹 久夫, 合葉 修一, 須藤 隆一1978 年 39 巻 4 号 p. 163-169
発行日: 1978/10/30
公開日: 2009/10/21
ジャーナル フリーGrowth, followed by detachment of periphyton was observed in an artificial stream receiving effluent from a secondary wastewater treatment plant. The cycle of growth and detachment was more conspicuous in summer (water temperature ranged nearly from 24 to 26°C) than in winter (water temperature from 12 to 19°C). This cycle was accompanied by a succession of dominant species of microorganisms in the periphyton. In the light of this work, the considerable pollution caused by periphyton in the Tama River, a shallow stream, running through metropolitan Tokyo, was discussed.抄録全体を表示PDF形式でダウンロード (925K) -
吉田 稔, 若尾 紀夫, 井上 克弘1978 年 39 巻 4 号 p. 170-175
発行日: 1978/10/30
公開日: 2009/10/21
ジャーナル フリーThe name Goshikinuma means a lake or pond having five colors. Actually, Lake Matsuo-Goshikinuma has had three distinct colors, namely, a heavily turbid brown hue, a slightly turbid, pale blue, and a clear blue. This phenomenon was accounted for as follows : The lake was supplied solely with underground water from the bottom, containing ferrous iron, hydrogen sulfide, but no dissolved oxygen. In the colder seasons from September to June, the lake water was in the circulation period and, therefore, was supplied with oxygen. Both ferrous iron and hydrogen sulfide in the water were continuously oxidized and gave a turbid brown color to the lake. In July, the lake was in the early stagnation stage, and dissolved oxygen decreased. Then, oxidation of some hydrogen sulfide but no ferrous iron had occurred. Thus, the lake color turned a slightly turbid, pale blue. In August, oxidation of neither ferrous iron nor hydrogen sulfide occurred as a result of stagnation, and the lake hue became a clear blue. It was also noticed that oxidation of ferrous iron was quite dependent on the activity of iron-oxidizing bacteria.抄録全体を表示PDF形式でダウンロード (832K) -
III. Ammonium Nitrogen in the Sediments of Different Water Regions神山 孝吉, 奥田 節夫, 河合 章1978 年 39 巻 4 号 p. 176-180
発行日: 1978/10/30
公開日: 2009/10/21
ジャーナル フリーIn natural water regions, there exists a large amount of ammonium nitrogen in sediments both in adsorbed form and in dissolved form. In order to clarify the movement of ammonium nitrogen in the sediments and to estimate its release rate from the sediments into the overlying water, the vertical distribution of ammonium nitrogen in the sediments in these forms was investigated. The following results were obtained : A seasonal variation was observed in the concentration of ammonium nitrogen in the interstitial water of the sediments where the temperature changed with seasons, and the concentration in summer was higher than that in winter (in Mikawa Bay and in Akanoi Bay, Lake Biwa). However, it was not observed in the sediments where the temperature did not show a remarkable change (Ie-1, Lake Biwa). In the sediments of each water region, there existed an obvious relationship between the amount of ammonium nitrogen dissolved in the interstitial water and that adsorbed on the mud particles. However, a local difference was observed in the relationship, and the ratio of the former to the latter was higher in a sea water region than in freshwater regions, which was considered to depend on the salinity of their interstitial waters. The fact agreed with the result obtained by the laboratory experiments that the ratio of dissolved ammonium nitrogen to adsorbed one increased by adding sodium chloride into the mud suspension.抄録全体を表示PDF形式でダウンロード (562K) -
IV. A Model for Ammonium Nitrogen Movement in the Surface Layer of Sediments神山 孝吉1978 年 39 巻 4 号 p. 181-188
発行日: 1978/10/30
公開日: 2009/10/21
ジャーナル フリーIn order to evaluate the effect of the bottom sediments on the overlying water quality in an aquatic environment, it is important to clarify the processes of movement and transformation of various substances in the surface layer of the sediments. The porosity of the sediments in this layer shows a gradual decrease with depth and biological activities of the transformation of substances are active.
In this paper, the author proposed a model for movement and the transformation of nitrogenous compounds in sediments, undergoing compaction and metabolic processes. This model was applied to the vertical distributions of ammonium nitrogen and particulate organic nitrogen in the sediments of the north basin of Lake Biwa and the following results were obtained : The vertical distribution of ammonium nitrogen in the interstitial water of the sediments was explained in terms of the rate of ammonium nitrogen generation in the sediments and the generation rate was estimated. The vertical distribution of organic nitrogen in the sediments was determined by the ratio of the coefficient of the first-order kinetics for the decomposition of particulated organic nitrogen to the sedimentation rate of particles on the bottom sediment surface (α/U0), the value of which was 5 (/cm). Under the assumption that organic nitrogen are decomposed into ammonium nitrogen and accumulated, the ratio of the diffusion coefficient of ammonium nitrogen in the interstitial water to the sedimentation rate (D/U0) was estimated to be 2, 000 (cm).
It was shown from the model that almost half of the particulated organic nitrogen deposited on the bottom sediments returned to the overlying water in the form of ammonium nitrogen. The sediments, therefore, play an important role for the overlying water by acting as the sink of particulated organic nitrogen and as the source of ammonium nitrogen in the water region.抄録全体を表示PDF形式でダウンロード (1177K)
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