Articles by Keyword: Acoustic Tags

Search results for Acoustic Tags

We found 28 results for you
  1. Reflection on the first five years of South Africa’s Acoustic Tracking Array Platform (ATAP): status, challenges and opportunities

    Reflection on the first five years of South Africa’s Acoustic Tracking Array Platform (ATAP): status, challenges and opportunities

    Item type: Journal Article • Journal: African Journal of Marine Science
    The Acoustic Tracking Array Platform (ATAP) is a marine science programme that monitors the movements and migrations of inshore marine animals along the South African coastline. Acoustically tagged animals are monitored by an expanded network of approximately 100 automated data-logging...
  2. Comparison of horse mackerel length frequencies obtained from research vessels and commercial midwater trawlers: implications for biomass estimation

    Comparison of horse mackerel length frequencies obtained from research vessels and commercial midwater trawlers: implications for biomass estimation

    Item type: Journal Article • Journal: South African Journal of Marine Science
    The validity of abundance estimates from hydroacoustic surveys relies, inter alia, on the ability of the fishing gear on the research vessel to sample non-selectively. This study compares the length frequencies of Cape horse mackerel Trachurus trachurus capensis taken in...
  3. 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...
  4. Evaluation of acoustic transmitter implantation and determination of post-translocation behaviour of largemouth bass <em>Micropterus salmoides</em> in a South African impoundment

    Evaluation of acoustic transmitter implantation and determination of post-translocation behaviour of largemouth bass <em>Micropterus salmoides</em> in a South African impoundment

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Largemouth bass Micropterus salmoides are an important angling species that are often displaced during catch-and-release fishing tournaments. The impact of acoustic transmitter implantation on this species and the effect of displacement distance on their behaviour were tested. In April 2010,...
  5. <em>In Situ</em> Measurements of the Acoustic Target Strength of Cape Horse Mackerel <em>Trachurus Trachurus Capensis</em> Off Namibia

    <em>In Situ</em> Measurements of the Acoustic Target Strength of Cape Horse Mackerel <em>Trachurus Trachurus Capensis</em> Off Namibia

    Item type: Journal Article • Journal: African Journal of Marine Science
    The acoustic target strength (TS) of Cape horse mackerel Trachurus trachurus capensis was measured in situ at 38 kHz during two surveys over the Namibian continental shelf in 1998 and 1999 using a SIMRAD EK500 echosounder/ES38D submersible split-beam transducer. Scattered...
  6. Distribution patterns of key fish species of the southern Benguela ecosystem: an approach combining fishery-dependent and fishery-independent data

    Distribution patterns of key fish species of the southern Benguela ecosystem: an approach combining fishery-dependent and fishery-independent data

    Item type: Journal Article • Journal: African Journal of Marine Science
    Within the context of an ecosystem approach for fisheries, there is a need for quantitative information on distributions of key marine species. This information is valuable input for modelling species interactions in the southern Benguela ecosystem. In the present study,...
  7. Interpreting behavioural data from Radio-Acoustic Positioning Telemetry (RAPT) systems

    Interpreting behavioural data from Radio-Acoustic Positioning Telemetry (RAPT) systems

    Item type: Journal Article • Journal: African Journal of Marine Science
    To detect behavioural patterns of individually tagged squid Loligo vulgaris reynaudii in a Radio-Acoustic Positioning Telemetry (RAPT) buoy array, trajectories reflecting the four dimensions of latitude, longitude, depth and time were plotted from data collected during field experiments in South...
  8. The potential for using acoustic tracking to monitor the movement of the West Coast rock lobster <em>Jasus lalandii</em>

    The potential for using acoustic tracking to monitor the movement of the West Coast rock lobster <em>Jasus lalandii</em>

    Item type: Journal Article • Journal: African Journal of Marine Science
    Although acoustic tracking has been used to study the movement of several species of clawed and spiny lobsters, only recent technological advances have provided sufficiently small transmitters to examine the utility of using acoustic tracking as a means to analyse...
  9. Vertical migration, catchability and acoustic assessment of semi-pelagic Cape horse mackerel <em>Trachurus trachurus capensis</em> in the southern Benguela

    Vertical migration, catchability and acoustic assessment of semi-pelagic Cape horse mackerel <em>Trachurus trachurus capensis</em> in the southern Benguela

    Item type: Journal Article • Journal: African Journal of Marine Science
    The vertical distribution and migration of the Cape horse mackerel Trachurus trachurus capensis were investigated on the basis of midwater and bottom trawl collections taken over diel cycles at two sites on South Africa's south coast. Attempts were also made...
  10. Quantifying the degree of protection afforded by a no-take marine reserve on an exploited shark

    Quantifying the degree of protection afforded by a no-take marine reserve on an exploited shark

    Item type: Journal Article • Journal: African Journal of Marine Science
    Sharks have been shown to benefit from the protection of marine protected areas (MPAs). There is, however, little information on the degree of protection by MPAs to shark populations. The movements of individual smoothhound sharks Mustelus mustelus in, and adjacent...