Articles by Keyword: Man Made Impoundments

Search results for Man Made Impoundments

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  1. POST-IMPOUNDMENT TRENDS IN THE FISH POPULATIONS OF THE HENDRIK VERWOERD DAM, SOUTH AFRICA

    POST-IMPOUNDMENT TRENDS IN THE FISH POPULATIONS OF THE HENDRIK VERWOERD DAM, SOUTH AFRICA

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Fish population changes in the Hendrik Verwoerd Dam are presented as sampled with a series of multifilament gill nets from Spring 1971 to Summer 1977. During this period, species such as Barbus halubi (smallmouth yellowfish), B. kimberleyensis (largemouth yellowfish), Labeo...
  2. ON THE STATUS OF CLARIAS GARIEPINUS (BURCHELL) IN LARGE MAN-MADE LAKES IN RHODESIA

    ON THE STATUS OF CLARIAS GARIEPINUS (BURCHELL) IN LARGE MAN-MADE LAKES IN RHODESIA

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Data from some large man-made lakes in Rhodesia suggest that the populations of Clarias gariepinus have declined in these lakes. The reasons for this are not clear although commercial fishing does not appear to be responsible.
  3. THE DETERMINATION OF CHLOROPHYLL <underline>a</underline> IN WATER CONTAINING SEDIMENT

    THE DETERMINATION OF CHLOROPHYLL <underline>a</underline> IN WATER CONTAINING SEDIMENT

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The presence of sediment at concentrations of 0,2% by mass in water samples significantly lowered the amount of chlorophyll a that could be measured. Two types of sediment differed in their ability to lower the chlorophyll a concentration. The chemically...
  4. RELATIVE FISH POPULATION DENSITY CHANGES IN THE P.K. LE ROUX DAM DURING THE FIRST THREE YEARS AFTER INUNDATION

    RELATIVE FISH POPULATION DENSITY CHANGES IN THE P.K. LE ROUX DAM DURING THE FIRST THREE YEARS AFTER INUNDATION

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Before inundation in September 1976 Barbus holubi and Labeo capensis were the dominant species each making up 46% of the total catch. Immediately after impoundment the relative density of B. holubi increased to 75% while that of L. capensis dropped...
  5. THE FOOD OF <em>BARBUS MATTOZI</em> GUIMARAES. 1884, (PISCES: CYPRINIDAE) IN A ZIMBABWE IMPOUNDMENT

    THE FOOD OF <em>BARBUS MATTOZI</em> GUIMARAES. 1884, (PISCES: CYPRINIDAE) IN A ZIMBABWE IMPOUNDMENT

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The food from the gut contents of 853 Barbus mattozi of various sizes were examined and analysed. The results showed a dietary transition from planktonivorous and omnivorous to piscivorous with increasing size of fish. At sizes larger than 230 nm...
  6. PREDICTION OF SURFACE WATER TEMPERATURE OF SOUTH AFRICAN IMPOUNDMENTS

    PREDICTION OF SURFACE WATER TEMPERATURE OF SOUTH AFRICAN IMPOUNDMENTS

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Temperature data for 18 South African impoundments were evaluated against Straskraba's global surface water predictive model. All impoundments exhibited quantifiable sinusoidal annual temperature variations which allowed for good predictive capabilities using Straskraba's empirical approach. For each impoundment coefficients for input...
  7. HYDROCLIMATE DEVELOPMENT FOLLOWING IMPOUNDMENT IN A TROPICAL AFRICAN MAN-MADE LAKE (LAKE ROBERTSON, ZIMBABWE)

    HYDROCLIMATE DEVELOPMENT FOLLOWING IMPOUNDMENT IN A TROPICAL AFRICAN MAN-MADE LAKE (LAKE ROBERTSON, ZIMBABWE)

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Lake Robertson was impounded by the Darwendale Dam which was completed in late 1976 to supplement the water supply to the City of Harare, Zimbabwe. This paper presents the results of a fortnightly sampling programme conducted on the lake between...
  8. Zooplankton community changes in Nhlabane estuary, South Africa, induced by man-made structures and drought

    Zooplankton community changes in Nhlabane estuary, South Africa, induced by man-made structures and drought

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    The Nhlabane estuary and coastal lake system has suffered a number of man-made impacts since 1977, when the lake and estuary were separated by the construction of a barrage. More recent man-made events included the construction of temporary sand walls,...
  9. Composition, abundance, distribution and seasonality of larval fishes in the Mngazi Estuary, South Africa

    Composition, abundance, distribution and seasonality of larval fishes in the Mngazi Estuary, South Africa

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    We investigated the larval fish assemblage in the intermittently-open Mngazi Estuary, in the subtropical/warm-temperate biogeographic boundary region of South Africa. Larvae were collected by means of boat-based plankton tows in summer and winter for a period of three years between...
  10. Does reservoir trophic status influence the feeding and growth of the sharptooth catfish, <em>Clarias gariepinus</em> (Teleostei: Clariidae)?

    Does reservoir trophic status influence the feeding and growth of the sharptooth catfish, <em>Clarias gariepinus</em> (Teleostei: Clariidae)?

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    The diet and growth of sharptooth catfish, Clarias gariepinus, in an oligotrophic system (Kat River Reservoir, Eastern Cape, South Africa) were compared to those in a eutrophic system (Laing Reservoir, Eastern Cape) to determine if the trophic status of a...