Articles by Author: Olf Weyl

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  1. An assessment of a light-attraction fishery in southern Lake Malawi

    An assessment of a light-attraction fishery in southern Lake Malawi

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    This study provides the first quantitative assessment of the light-attraction component of a small-scale purse seine, locally known as a chilimira net, fishery in two areas of southern Lake Malawi. For monitoring purposes the shoreline of Lake Malawi is divided...
  2. An assessment of the <em>nkacha</em> net fishery of Lake Malombe, Malawi

    An assessment of the <em>nkacha</em> net fishery of Lake Malombe, Malawi

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Since the early 1990s the fishery of Lake Malombe, Malawi, has been dominated by haplochromine cichlids which are mainly harvested with a small-scale purse seine called an nkacha net. The annual landings from the fishery declined from 9 500 tons...
  3. Growth, reproduction and population structure of <em>Diplotaxodon limnothrissa</em> in the southeast arm of Lake Malawi

    Growth, reproduction and population structure of <em>Diplotaxodon limnothrissa</em> in the southeast arm of Lake Malawi

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Diplotaxodon limnothrissa is a widely distributed species occurring throughout Lake Malawi from the surface to a depth of at least 220m. It is probably the most abundant cichlid in the lake, with biomass estimates of around 87 000t in the...
  4. Management advice for the <em>Diplotaxodon limnothrissa</em> (Teleostei: Cichlidae) resource in the south-east arm of Lake Malawi, based on per-recruit analysis

    Management advice for the <em>Diplotaxodon limnothrissa</em> (Teleostei: Cichlidae) resource in the south-east arm of Lake Malawi, based on per-recruit analysis

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Diplotaxodon limnothrissa is a widely distributed species occurring throughout Lake Malawi and is probably the most abundant cichlid in the pelagic zone of the lake. The species is exploited commercially in the south-east arm of the lake, but since the...
  5. The effect of largemouth bass <em>Micropterus salmoides</em> on aquatic macro-invertebrate communities in the Wit River, Eastern Cape, South Africa

    The effect of largemouth bass <em>Micropterus salmoides</em> on aquatic macro-invertebrate communities in the Wit River, Eastern Cape, South Africa

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Fish predation is one of the driving forces of freshwater invertebrate community structures, with alien predators having a pronounced effect. A quantitative assessment of aquatic invertebrates in the Wit River, Sundays River catchment, Eastern Cape, South Africa, was undertaken to...
  6. 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,...
  7. Fish distributions in the Rondegat River, Cape Floristic Region, South Africa, and the immediate impact of rotenone treatment in an invaded reach

    Fish distributions in the Rondegat River, Cape Floristic Region, South Africa, and the immediate impact of rotenone treatment in an invaded reach

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Alien fishes are considered the most serious threat to native headwater stream fishes in South Africa. A 4 km reach of the Rondegat River is the first section of a South African river to be rehabilitated through the attempted removal...