Articles by Keyword: Diel Vertical Migration

Search results for Diel Vertical Migration

We found 93 results for you
  1. ZOOPLANKTON AND ENVIRONMENTAL CONDITIONS IN GROENVLEI, SOUTHERN CAPE, DURING 1976

    ZOOPLANKTON AND ENVIRONMENTAL CONDITIONS IN GROENVLEI, SOUTHERN CAPE, DURING 1976

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The zooplankton and environmental conditions in Groenvlei were studied during 1976 as part of an overall ecological study of the zooplankton of the Wilderness Lakes system. The Groenvlei water was found to be well mixed and low in dissolved PO4−P,...
  2. ZOOPLANKTON DISTRIBUTION IN RELATION TO ENVIRONMENTAL CONDITIONS IN THE SWARTVLEI SYSTEM, SOUTHERN CAPE

    ZOOPLANKTON DISTRIBUTION IN RELATION TO ENVIRONMENTAL CONDITIONS IN THE SWARTVLEI SYSTEM, SOUTHERN CAPE

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Swartvlei is an ectogenic meromictic coastal lake connected to the sea via an estuary which closes periodically due to the formation of a sand bar across its mouth. The inflow of high-salinity water water from the sea into the lake...
  3. ZOOPLANKTON AND ENVIRONMENTAL CONDITIONS IN A SOUTHERN CAPE COASTAL LAKE SYSTEM

    ZOOPLANKTON AND ENVIRONMENTAL CONDITIONS IN A SOUTHERN CAPE COASTAL LAKE SYSTEM

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The usually natural closing and artificial opening of the Tow River mouth to the sea have a major influence on the physico-chemical environmental conditions in the coastal lake system formed by the Tow River, Eilandvlei, Langvlei and Rondevlei, as it...
  4. Observations on the Diel Vertical Distribution of Hydromedusae in the Southern Benguela

    Observations on the Diel Vertical Distribution of Hydromedusae in the Southern Benguela

    Item type: Journal Article • Journal: African Journal of Marine Science
    Diel vertical migration (DVM) of six common species of hydromedusae was investigated during two drogue studies conducted in St Helena Bay on the west coast of South Africa in February 1995. Clytia spp., Obelia spp. and Bougainvillia macloviana, were largely...
  5. The effects of physiology and behaviour on the near-bottom distributions of <em>Kareniabrevis</em> on the West Florida shelf: a numerical study

    The effects of physiology and behaviour on the near-bottom distributions of <em>Kareniabrevis</em> on the West Florida shelf: a numerical study

    Item type: Journal Article • Journal: African Journal of Marine Science
    The distribution of near-bottom populations of Karenia brevis depends on both cell physiology and behaviour. The migration distance of cells, and the subsequent exposure to light, may vary as a result of the nocturnal uptake of nitrate. The adaptive advantage...
  6. Thermal constraints on the respiration and excretion rates of krill, <em>Euphausia hanseni</em> and <em>Nematoscelis megalops</em>, in the northern Benguela upwelling system off Namibia

    Thermal constraints on the respiration and excretion rates of krill, <em>Euphausia hanseni</em> and <em>Nematoscelis megalops</em>, in the northern Benguela upwelling system off Namibia

    Item type: Journal Article • Journal: African Journal of Marine Science
    Rates of respiration and ammonia excretion of Euphausia hanseni and Nematoscelis megalops were determined experimentally at four temperatures representative of conditions encountered by these euphausiid species in the northern Benguela upwelling environment. The respiration rate increased from 7.7 µmol O2...
  7. Diel vertical migration of anchovy <em>Engraulis encrasicolus</em> larvae in the northern Benguela

    Diel vertical migration of anchovy <em>Engraulis encrasicolus</em> larvae in the northern Benguela

    Item type: Journal Article • Journal: African Journal of Marine Science
    The diel vertical migration of anchovy Engraulis encrasicolus larvae was studied in the northern Benguela during a survey in April 2001. The diel pattern is described in relation to the degree of swimbladder inflation and the vertical structure of temperature...
  8. Dynamics of the pelagic component of Namibian hake stocks

    Dynamics of the pelagic component of Namibian hake stocks

    Item type: Journal Article • Journal: South African Journal of Marine Science
    A study was undertaken to investigate the spatial, diurnal and interannual dynamics of the pelagic component of Namibian hake stocks. Data were derived from trawl surveys conducted on board the R.V. Dr Fridtjof Nansen during the period 1991–1999. In addition...
  9. REVERSED VERTICAL MIGRATION OF PLANKTONIC CRUSTACEANS IN A EUTROPHIC LAKE OF HIGH pH

    REVERSED VERTICAL MIGRATION OF PLANKTONIC CRUSTACEANS IN A EUTROPHIC LAKE OF HIGH pH

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Two studies of the diel vertical migration of zooplankton in the hyper-eutrophic Hartbeespoort Dam, revealed that both in summer when the lake was anaerobic below 15 m depth, and in winter, when homogeneous, aerobic conditions existed throughout the water column,...
  10. Diel and tidal variations in larval fish exchange in the mouth region of the Gamtoos Estuary, South Africa

    Diel and tidal variations in larval fish exchange in the mouth region of the Gamtoos Estuary, South Africa

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Diel and tidal variations in density of larval fishes were monitored over one neap and one spring tidal cycle in the mouth region of the warm temperate Gamtoos Estuary, South Africa. Data were collected over two 24h periods, using mixed...