Articles by Keyword: Acoustic Survey

Search results for Acoustic Survey

We found 122 results for you
  1. Revised estimates of abundance of South African sardine and anchovy from acoustic surveys adjusting for echosounder saturation in earlier surveys and attenuation effects for sardine

    Revised estimates of abundance of South African sardine and anchovy from acoustic surveys adjusting for echosounder saturation in earlier surveys and attenuation effects for sardine

    Item type: Journal Article • Journal: African Journal of Marine Science
    Hydro-acoustic surveys have been used to provide annual estimates of May recruitment and November spawner biomass of the South African sardine Sardinops sagax and anchovy Engraulis encrasicolus resources since 1984. These time-series of abundance estimates form the backbone of the...
  2. Megabenthos and benthopelagic fishes on Southeast Atlantic seamounts

    Megabenthos and benthopelagic fishes on Southeast Atlantic seamounts

    Item type: Journal Article • Journal: African Journal of Marine Science
    In a descriptive study of megafauna of several Southeast Atlantic seamounts, multiple video-transects on upper slopes and summits documented the occurrence of benthic invertebrate taxa, primarily corals, regarded as indicators of vulnerable marine ecosystems (VMEs) as defined in international guidelines...
  3. Indigenous High Forests in the Transvaal with Special Reference to Inventory and Monitoring Systems

    Item type: Journal Article • Journal: South African Forestry Journal
    The indigenous forests in the Transvaal comprise a total area of 35 385 ha, of which 18 088 ha or 51% are situated on State forest land. The forests are found mainly along the Drakensberg escarpment and, to a lesser...
  4. Ergonomic Research in South African Forestry

    Item type: Journal Article • Journal: South African Forestry Journal
    After a short reflection on the South African forest industry the article discusses various research projects in ergonomics.
  5. Pasture‐use patterns on dairy and beef farms in the natal midlands

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    Pasture sites for each of the species grown are classified for both dryland and irrigated pastures in the Natal Midlands. Only six species viz. kikuyu, Italian ryegrass, Eragrostis curvula, Festuca arundinacea (tall fescue), Dactylis glomerata (cocksfoot) and Trifolium repens (white...
  6. Geographical variation in the seasonal moth flight activity of the maize stalk borer, <em>Busseola fusca</em> (Fuller), in South Africa

    Geographical variation in the seasonal moth flight activity of the maize stalk borer, <em>Busseola fusca</em> (Fuller), in South Africa

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The seasonal abundance of Busseola fusca moths at five localities in the maize production area of South Africa was monitored by means of Robinson light traps. Geographical variation in the flight pattern was shown to exist between localities from east...
  7. A CHECKLIST OF THE FISH SPECIES OF THE CROCODILE AND MATLABAS RIVERS (LIMPOPO SYSTEM) OF THE TRANSVAAL

    A CHECKLIST OF THE FISH SPECIES OF THE CROCODILE AND MATLABAS RIVERS (LIMPOPO SYSTEM) OF THE TRANSVAAL

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    This paper reports on the results of a fish distribution survey of the Crocodile and Matlabas Rivers (Limpopo System). Fifteen species are recorded for the first time in the Matlabas River. Seven unlisted species are recorded for the Crocodile River,...
  8. Weed survey in cotton (<em>Gossypium hirsutum</em> L.) and sunflower (<em>Helianthus annuus</em> L.) fields in the Pandamatenga plains of northeastern Botswana

    Weed survey in cotton (<em>Gossypium hirsutum</em> L.) and sunflower (<em>Helianthus annuus</em> L.) fields in the Pandamatenga plains of northeastern Botswana

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Sunflower and cotton fields in the Pandamatenga plains of northeastern Botswana were surveyed in 1998 and 1999 for weed infestations. Twenty-seven and 24 species were identified from the fields in 1998 and 1999, respectively. Nineteen and 17 species were found...
  9. Disaggregation of land types using terrain analysis, expert knowledge and GIS methods

    Disaggregation of land types using terrain analysis, expert knowledge and GIS methods

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Soil maps’ value is increasingly recognised for enabling the optimal management of ecosystems. Digital soil mapping (DSM) can overcome the cost constraints of traditional mapping methods, but requires local area-specific research. As South Africa is blessed with the land type...
  10. AIDS communications through social networks: catalyst for behaviour changes in Uganda

    AIDS communications through social networks: catalyst for behaviour changes in Uganda

    Item type: Journal Article • Journal: African Journal of AIDS Research
    Objective: To investigate distinctive communications through social networks which may be associated with population behaviour changes and HIV prevalence declines in Uganda compared to other countries.