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Cabbage seed germination for the assessment of adjuvant effects on 2, 4-D iso-octyl ester volatility
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.L. Schubert --- , Republic of South Africa D.J. Erasmus --- , Republic of South Africa L.P. van Dyk --- , Republic of South Africa V. Gray --- Department of Botany, Republic of South AfricaThe germination rate of cabbage seeds (Brassica oleracea cv. Hercules) exposed to the vapour of the 2,4-dichlorophenoxy iso-octyl ester (2,4-D IOE) was used in a bioassay to determine the effectiveness of commercial adjuvants in reducing the volatility of this hormonal... -
Conservation genetics of the vulnerable Treur River barb, Barbus treurensis
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: GD Engelbrecht PFS Mulder SK MpherwaneAt present there are only two populations of the vulnerable Treur River barb, Barbus treurensis, in existence; a founder population in the upper Blyde River and a translocated population in the Treur River where the species became extinct. The translocated... -
Use of Plastic Drift Cards As Indicators of Possible Dispersal of Propagules of the Mangrove Avicennia Marina by Ocean Currents
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: T. D. Steinke C. J. WardPlastic drift cards with the same buoyancy as propagules of Avicennia marina (Forssk.) Vierh. were used as an indicator of possible mangrove dispersal by ocean currents. The cards were dropped from an aircraft into the sea at the mouths of... -
Spawning strategies and transport of early stages of the two Cape hake species, Merluccius paradoxus and M. capensis, in the southern Benguela upwelling system
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: B Grote --- , Germany EK Stenevik --- , Norway W Ekau --- , Germany HM Verheye --- Oceans and Coasts Research, Department of Environmental Affairs, South Africa MR Lipiński --- Branch: Fisheries, Department of Agriculture, South Africa W Hagen --- Marine Zoology, GermanySeasonal and short-term variability of environmental parameters influence the spawning strategies of fish species. In this study, the spawning strategies and the transport of early stages of the two Cape hake species off South Africa were investigated. Distribution of eggs... -
Assessing the ecosystem effects of the abalone Haliotis midae from its diet and foraging behaviour
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: Z Zeeman --- Department of Zoology and Marine Research Institute, South Africa GM Branch --- Department of Zoology and Marine Research Institute, South Africa TP Peschak --- Department of Zoology and Marine Research Institute, South Africa D Pillay --- Department of Zoology and Marine Research Institute, South AfricaThe South African abalone Haliotis midae is commercially exploited and seriously threatened by overfishing. This not only affects the species itself but potentially the functioning of the ecosystem because of associated changes in community structure. The nature of effects that... -
Phylogeographic structure of the caridean shrimp Palaemon peringueyi in South Africa: further evidence for intraspecific genetic units associated with marine biogeographic provinces
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: PR Teske PW Froneman NP Barker CD McQuaidRecent genetic studies have shown that most widely distributed, passively dispersing invertebrates in southern Africa have regional intraspecific units that are associated with the three main marine biogeographic provinces (cool-temperate, warm-temperate and subtropical). The caridean shrimp Palaemon peringueyi also occurs... -
Recent shoreline changes in the Volta River delta, West Africa: the roles of natural processes and human impacts
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: EJ Anthony --- Aix-Marseille University, France R Almar --- LEGOS (CNRS-IRD-CNES-University of Toulouse), France T Aagaard --- University of Copenhagen, DenmarkThe Volta River delta developed as an asymmetric lobe in a tectonic offset on the coast of Ghana. The delta comprises a large curvilinear spit that widens in its central portion due to the adjunction of successive sandy beach ridges... -
Circulation of shelf waters in the KwaZulu-Natal Bight, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MJ Roberts --- Ocean Sciences and Marine Food Security, South Africa C Nieuwenhuys --- Bayworld Centre for Research and Education, South Africa LA Guastella --- Bayworld Centre for Research and Education, South AfricaShip-based acoustic Doppler current profiler (S-ADCP) technology, used in survey mode, has enabled near- synoptic views of the in situ 3-D current field in the KwaZulu-Natal (KZN) Bight to be elucidated for the first time. Data acquired by the research... -
Genetic structure of wild and domesticated grasscutters (Thryonomys swinderianus) from south-western Nigeria
Item type: Journal Article • Journal: African Zoology • Authors: Oluwakayode M Coker --- Department of Wildlife and Ecotourism Management, Nigeria Abosede O Omonona --- Department of Wildlife and Ecotourism Management, Nigeria Olusegun A Fagbohun --- Department of Veterinary Microbiology and Parasitology, Nigeria Cortney Pylant --- Department of Wildlife Ecology and Conservation, USA James D Austin --- Department of Wildlife Ecology and Conservation, USAGrasscutter (Thryonomys swinderianus) is a large rodent distributed across sub-Saharan Africa that is highly valued as a source of protein. There has been little effort to evaluate the genetic structure of grasscutters despite long-term harvesting pressure and over 40 years... -
The persistence of firm-specific post-earnings announcement returns
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Dong Hyun Son --- College of Business, Korea Dan Palmon --- Department of Accounting and Information System, New Jersey Ari Yezegel --- Department of Accountancy, USAThis paper examines whether estimates of post-earnings-announcement returns derived from the historical firm-specific relation between earnings and returns help predict future post-earnings-announcement returns. We find that firms with historically high post-earnings announcement returns continue to exhibit high post-earnings announcement returns... -
Invertebrate drift densities in the Njoro and Kamweti Rivers in the Kenyan highlands that differ in the level of anthropogenic disturbances
Item type: Journal Article • Journal: African Zoology • Authors: Charles M M’Erimba --- Department of Biological Sciences, Kenya John G Mbaka --- Department of Land and Water Management, Kenya Priscilla W Mureithi --- Department of Biological Sciences, Kenya Ken O Ouma --- Department of Biological Sciences, KenyaInvertebrate drift is one of several fundamental ecological processes in streams. However, little is known about the dynamics of invertebrate drift in Kenyan streams. In this study, we assessed invertebrate drift in two rivers, i.e. Njoro and Kamweti, that differ... -
Kelp forests in False Bay: urchins vs macroalgae in South Africa’s southwest coast biogeographical transition zone
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: K Morris --- , South Africa LK Blamey --- , South AfricaKelp forests along South Africa's southwest coast occur in a region of biogeographical overlap. Commonly referred to as transition-zone kelp forests, these dynamic ecosystems are particularly susceptible to grazing from species such as urchins. This study explores relationships between urchins... -
Response of the barrier island coastal region of southwestern Nigeria to climate and non-climate forcing
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: IB Danladi --- Department of Geological Engineering, Turkey M Gül --- Department of Geological Engineering, Turkey E Ateş --- Vocational School of Ayaş, TurkeyDespite threats emanating from the influence of climate and non-climate forcing on the barrier island coastal region of southwestern Nigeria, the extent of the coastal erosion is poorly understood. We report evidence of coastal erosion and sediment accumulation in the... -
The Elephant Marsh, Malawi – Part 3: the application of an eco-social model to assess options for managing ecological status
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: C Brown --- , South Africa A Joubert --- , South Africa J Turpie --- , South Africa K Reinecke --- , South Africa A Birkhead --- , South Africa K Forsythe --- , South Africa T Davies --- , United Kingdom W Mgoola --- , Malawi J Nyirenda --- , Malawi R Arthur --- , United KingdomIn 2016, an application was prepared by the Malawian government for the Elephant Marsh on the Shire River to be granted RAMSAR status. As part of the support for that application and to help guide the resulting management plan, the... -
The Elephant Marsh, Malawi – Part 2: two-dimensional hydrodynamic modelling in support of an eco-social assessment
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: AL Birkhead --- , South Africa MK Reinecke --- , South Africa CA Brown --- , South Africa WO Mgoola --- , Malawi JK Nyirenda --- , MalawiThe Elephant Marsh lies on the floodplain of the lower Shire River, in southern Malawi. It is both a cultivated, seasonal floodplain and a wetland, characterised by a complex mosaic of meandering channels, marshland and shallow lakes. In 2016, the...