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Nearshore surface current patterns in the Tsitsikamma National Park, South Africa
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: C. G. Attwood J. Allen P. J. ClaassenThe pattern of surface currents in the Tsitsikamma National Park, South Africa, was studied with holey-sock drogues released in batches of up to four at a time, from 1996 and 1998. Drogues were left to drift for either 6 or... -
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... -
Adult Movement and Larval Dispersal of Argyrozona Argyrozona (Pisces: Sparidae) from a Temperate Marine Protected Area
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: S. L. Brouwer M. H. Griffiths M. J. RobertsAdult emigration and larval dispersal of carpenter Argyrozona argyrozona from the Tsitsikamma National Park (TNP), South Africa, were investigated using mark-recapture data and Acoustic Doppler Current Profiler measurements of currents. Tagging data showed that adult carpenter were mainly resident, with... -
Oceanic variability in the western sector of Algoa Bay, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: EH Schumann JRS Churchill HJ ZaaymanThe city of Port Elizabeth lies in the western sector of Algoa Bay, and a number of projects have investigated the oceanic temperature, salinity and current structures in the vicinity. This paper analyses past results, and then incorporates measurements of... -
Currents along the Tsitsikamma coast, South Africa, and potential transport of squid paralarvae and ichthyoplankton
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MJ Roberts M van den BergIn July 1998, a bottom-mounted Acoustic Doppler Current Profiler was deployed at 36m depth in the centre of the Tsitsikamma National Park on the eastern Agulhas Bank, South Africa. The purpose was to investigate transport of chokka squid Loligo vulgaris... -
Growth patterns of the pearl oyster Pinctada margaritifera L. in Gazi Bay, Kenya
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: KM Mavuti EN Kimani T MukiamaCulture of pearl oysters is rapidly increasing worldwide, including the western Indian Ocean. The oyster Pinctada margaritifera L., which produces the most highly valued black pearls, occurs in East Africa, a nd as been exploited there for the shell for... -
Coastal currents and temperatures along the eastern region of Algoa Bay, South Africa, with implications for transport and shelf–bay water exchange
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MJ Roberts --- Department of Environmental Affairs, South AfricaBoat ADCP surveys and an eight-month deployment of a 1 200 kHz ADCP were used to study the nearshore (5–25 m depth) current and temperature patterns along the eastern coastal region of Algoa Bay, on the south-east coast of South... -
Upwelling and ocean structures off Algoa Bay and the south-east coast of South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: WS Goschen --- South African Environmental Observation Network (SAEON), South Africa EH Schumann --- Department of Geosciences, South Africa KS Bernard --- South African Environmental Observation Network (SAEON), South Africa SE Bailey --- South African Environmental Observation Network (SAEON), South Africa SHP Deyzel --- South African Environmental Observation Network (SAEON), South AfricaAs the Agulhas Current flows along the south-east coast of South Africa, a number of processes operate that bring cold, deep water up onto the narrow shelf. As a consequence, upwelling along the coastline is enhanced farther southward and downstream... -
Shallow-water, nearshore current dynamics in Algoa Bay, South Africa, with notes on the implications for larval fish dispersal
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: P Pattrick --- Department of Ichthyology and Fisheries Science, South Africa NA Strydom --- , South Africa WS Goschen --- , South AfricaNearshore currents play a vital role in the transport of eggs and larval stages of fish. However, little is known about their complexity and the implications for dispersal of fish larvae. The study describes the complexity of the shallow nearshore... -
Dynamics and role of the Durban cyclonic eddy in the KwaZulu-Natal Bight ecosystem
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: LA Guastella --- Bayworld Centre for Research and Education, South Africa MJ Roberts --- Ocean Sciences and Marine Food Security, South AfricaThe semi-permanent Durban Eddy is a mesoscale, lee-trapped, cold-core cyclonic circulation that occurs off the east coast of South Africa between Durban in the north and Sezela, some 70 km to the south. When present, strong north-eastward countercurrents reaching 100... -
Modelling the tides and their impacts on the vertical stratification over the Sofala Bank, Mozambique
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: CM Chevane --- Instituto Nacional de Hidrografia e Navegação, Mozambique P Penven --- LMI ICEMASA, Laboratoire de Physique des Océans, France FPJ Nehama --- Escola Superior de Ciências Marinhas e Costeiras, Mozambique CJC Reason --- Department of Oceanography, South AfricaThe Sofala Bank, a wide shelf located along the central coast of Mozambique, hosts tides with high amplitudes. The Regional Ocean Modelling System (ROMS) was used to analyse the tidal currents on the bank and to investigate their effects on... -
Characterising the seasonal cycle of wind forcing, surface circulation and temperature around the sub-Antarctic Prince Edward Islands
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: T Toolsee --- , South Africa T Lamont --- , South Africa M Rouault --- , South Africa I Ansorge --- , South AfricaLocated between the sub-Antarctic Front and the Antarctic Polar Front, the Prince Edward Islands (PEIs) provide an essential breeding ground for top predators and are an ideal location to investigate disturbances linked to climate change. This study provides the first... -
Cross-shelf movement of Chrysaora fulgida (Scyphozoa; Discomedusae) off Namibia inferred from stable isotopes (δ15N and δ13C)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: H Skrypzeck --- , South Africa CD van der Lingen --- , South Africa MJ Gibbons --- , South AfricaLarge and small specimens of two species of metagenic Scyphozoa (true jellyfishes) can be found in nearshore waters off central Namibia throughout the year. Whereas populations of Chrysaora africana are largely restricted to inshore waters, C. fulgida occurs across the... -
Investigating the influence of the extreme Indian Ocean Dipole on the 2020 influx of Red-necked Phalaropes Phalaropus lobatus in Kenya
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Raphaël Nussbaumer --- , Kenya Mathieu Gravey --- , Switzerland Améline Nussbaumer --- , Kenya Colin Jackson --- , KenyaOcean currents have wide-ranging impacts on seabird movement and survival. By extension, the extreme oscillations they are subject to, such as extreme Indian Ocean Dipole (IOD) events, can also be expected to dramatically influence seabird populations. This study links the...