陸水学雑誌
Online ISSN : 1882-4897
Print ISSN : 0021-5104
ISSN-L : 0021-5104
34 巻, 3 号
選択された号の論文の5件中1~5を表示しています
  • 山口 征矢, 高橋 正征, 市村 俊英, 森谷 虎彦
    1973 年 34 巻 3 号 p. 121-128
    発行日: 1973/07/01
    公開日: 2009/10/21
    ジャーナル フリー
    Physico-chemical and biological properties of Lake Yogo-ko were investigated in the summer of 1969. A weak thermal stratification was observed with a gradient of 0.5° per meter in the depth of 4-8m. In late summer, dissolved oxygen disappeared in the layer near bottom. The concentration of NH3-N varied from 48 μg/l in early summer to 2 μg/l in late summer, whereas PO4-P was present close on the same concentration (15-23 μg/l). Melosira italica and Melosira granulata were dominant during June and August, and Ceratium hirundinella in September. The amount of chlorophyll-a in the whole water column varied in a range of 40 mg/m2 to 48 mg/m2 and the daily net primary production ranged from 0.75 g CO2/m2/day to 0.88 g CO2/m2/day during the summer. Upon surveying the data of the last thirty years, Lake Yogo-ko has progressed in eutrophication rapidly in the last decade, and it is moderately eutrophic at present.
  • 小椋 和子
    1973 年 34 巻 3 号 p. 129-135
    発行日: 1973/07/01
    公開日: 2009/10/21
    ジャーナル フリー
    わが国の代表的な都市河川である多摩川の水中から6種類のステロールが分離され, 確認された.多摩川は, 工業排水によるよりも家庭廃水による汚染が大きいといわれている.今回検出されたステロールのおもなものは, 屎の中に存在するコプロスタノールとコレステロールであった.また植物ステロールであるブラッシカステロール, カンペステロール, スチグマステロール, β-シトステロールが少量検出された.
    河川水は, Whatman GF/Cでろ過したろ液とフィルターに残存した懸濁物にわけて判定した.
    溶存態 (ろ液に存在している) ステロールのうち, コレステロールとコプロスタノールは, 1970年から1973年にかけて, それぞれ, 4.4~14.9μg/l, 1.8~5.8μg/lに増加した.
    1972~1973年に測定した他のステロールは, ブラッシカステロール : 1.0~2.0μg/l, カンペステロール : 0.7~0.8μg/l, スチグマステロール : 1.3~1.8μg/l, β-シトステロール : 3.7~5.5μg/lである.一方, 懸濁物中のステロールは, コレステロール : 7.7~13.1μg/l, コプロスタノール : 6.8~9.5μg/l, ブラッシカステロール : 1.6~1.7μg/l, カンペステロール : 1.4~2.0μg/l, スチグマステロール : 0.9~2.4μg/l, β-シトステロール : 4.2~6.1μg/lである.
    ステロールの確認はGC-MSによりおこなわれた.
  • 加藤 武雄
    1973 年 34 巻 3 号 p. 136-142
    発行日: 1973/07/01
    公開日: 2009/10/21
    ジャーナル フリー
    The surrounding area of the Nabekoshi Pass in Yamagata Prefecture is famous for a heavy snow fall in winter. The district is characterized by an abundance of small lakes and swamps, among which Lake Wakahata-numa is a representative one. In this paper, this lake is treated from the standpoint of regional limnology. The results of the investigations are summarized in the followings :
    1. The morphometrical data calculated from the bathymetric map are :
    Surface area…1.42×104m2
    Length of shore line…508m
    Maximum depth…11m
    Volume…6.48×104m3
    Shore development…1.2
    The amount of seepage from the bottom of the lake is about 1, 400m3 per day. In the season of rapid thaws, the lake water is turned over by the inflowing melt water only for four days.
    2. In mid-summer, the development of thermal and chemical stratifications is observed in this lake.
    3. The main constituent of dissolved minerals is sodium chloride derived from the atmospheric salt which is transported by the melt water.
    4. Total amount of dissolved substances in this lake is estimated at about four tons from summer to autumn. At the season of thaws, it decreases to about a half.
  • 福島 博, 平本 俊明
    1973 年 34 巻 3 号 p. 143-150
    発行日: 1973/07/01
    公開日: 2009/10/21
    ジャーナル フリー
    The algal studies have been made on the Secondary Settle Tank in the Yokohama Chubu Sewage Treatment Plant from September 1968 to April 1969, during which 59 taxa of diatoms were found. Among these taxa, Navicnla confervacea and Nitzschia palea are dominant.
  • 山口 征矢, 高橋 正征, 市村 俊英, 森谷 虎彦
    1973 年 34 巻 3 号 p. 157-163
    発行日: 1973/07/01
    公開日: 2009/10/21
    ジャーナル フリー
    Further observations on the physico-chemical and biological properties of Lake Yogo-ko were made just after the fall overturn. Lacustrine factors did not show a definite vertical stratification at any location, but two water masses were detected in the lake : one is a nutrient rich colder water mass at the northern part and the other is a relatively nutrient poor warmer water mass at the southern part. Standing crop of phytoplankton assessed by chlorophyll-a was about 88 mg/m2. This value was approximately two times higher than those in summer. A photosynthetic activity of phytoplankton in situ measured on a cloudy day was 11 mg CO2/mg. chl./day and a daily net primary production was 0.44 g CO2/m2/day. These values were nearly one-half of those measured on sunny day in summer, but a potential photosynthetic activity was almost the same order compared with that of summer phytoplankton.
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