The Importance of the Thukela River Estuary, East Coast of South Africa, for the Biology of the Near-Shore Environment and Associated Human Aspects: A Review

2016 ◽  
pp. 53-65 ◽  
Author(s):  
Ander M. De Lecea ◽  
Rachel Cooper
Keyword(s):  
South Africa ◽  
East Coast ◽  
River Estuary ◽  
Human Aspects ◽  
Near Shore

Implications for the age of South African Devonian rocks in which Tropidoleptus (Brachiopoda) has been found

1983 ◽  
Vol 120 (1) ◽  
pp. 51-58 ◽  
Author(s):  
A. J. Boucot ◽  
C. H. C. Brunton ◽  
J. N. Theron
Keyword(s):  
South Africa ◽  
North America ◽  
South African ◽  
Early Carboniferous ◽  
Fossil Plants ◽  
Geological Time ◽  
Marine Sedimentation ◽  
History Of ◽  
Near Shore ◽  
First Time

SummaryThe Devonian brachiopod Tropidoleptus is recognized for the first time in South Africa. It is present in the lower part of the Witteberg Group at four widely separated localities. Data regarding the stratigraphical range of the genus elsewhere, combined with information on recently described fossil plants and vertebrates from underlying strata of the upper Bokkeveld Group, suggest that a Frasnian or even Givetian age is reasonable for the lower part of the Witteberg Group. The recognition of Tropidoleptus in a shallow water, near-shore, molluscan association, at the top of the South African marine Devonian sequence, is similar to its occurrence in Bolivia, and suggests a common Malvinokaffric Realm history of shallowing, prior to later Devonian or early Carboniferous non-marine sedimentation. It is noteworthy that Tropidoleptus is now known to occur in ecologically suitable environments around the Atlantic, but is absent from these same environments in Asia and Australia. Tropidoleptus is an excellent example of dispersal in geological time — first appearing in northern Europe and Nova Scotia, then elsewhere in eastern North America and North Africa, followed by South America and South Africa, while continuing in North America.

scholarly journals Population irruption of the clam Meretrix morphina in Lake St Lucia, South Africa

2017 ◽  
Vol 113 (7/8) ◽  
Author(s):  
Nelson A. F. Miranda ◽  
Nasreen Peer ◽  
Renzo Perissinotto ◽  
Nicola K. Carrasco ◽  
Salome Jones ◽  
...  
Keyword(s):  
South Africa ◽  
South African ◽  
East Coast ◽  
Severe Drought ◽  
Freshwater Input ◽  
Large Populations ◽  
Ocean Region ◽  
West Indian Ocean ◽  
First Time ◽  
Eastern Seaboard

The thick-shelled clam Meretrix morphina, previously referred to as Meretrix meretrix, now occurs in the west Indian Ocean region, along the eastern seaboard of Africa, from the Red Sea to the Mlalazi Estuary, close to the Tugela River. Its presence in South Africa is only of recent recording. Meretrix morphina was detected for the first time in Lake St Lucia in 2000. The population declined and was not detected from 2005 until 2011, most likely as a result of a severe drought that resulted in widespread desiccation and hypersalinity in the lake. The system then experienced increased freshwater input resulting in lower salinities from 2011 until 2014, during which time M. morphina reappeared and their population gradually increased. In 2015, M. morphina became abundant in St Lucia, attaining unprecedented densities of 447 ind./m2. Biomass, expressed as a fresh weight, varied in the different basins of St Lucia, ranging from 195 g/m2 at Lister’s Point to 1909.8 g/m2 at Catalina Bay. However, in 2016, when drought conditions returned, M. morphina disappeared. This species appears to thrive under brackish salinities and high temperatures. It is able to establish large populations with high biomass and can become dominant. However, M. morphina is sensitive to desiccation and hypersaline conditions. This clam has substantial commercial value and is exploited along the African east coast, particularly in Mozambique. In future, it may feature more prominently in South African estuaries. However, the ecology of M. morphina is still largely unknown.

Possible maternal offloading of metals in the plasma, uterine and capsule fluid of pregnant ragged-tooth sharks (Carcharias taurus) on the east coast of South Africa

2017 ◽  
Vol 24 (20) ◽  
pp. 16798-16805 ◽  
Author(s):  
Kristina Naidoo ◽  
Anil Chuturgoon ◽  
Geremy Cliff ◽  
Sanil Singh ◽  
Megan Ellis ◽  
...  
Keyword(s):  
South Africa ◽  
East Coast ◽  
Carcharias Taurus

scholarly journals Contribution of Biological Effects to the Carbon Sources/Sinks and the Trophic Status of the Ecosystem in the Changjiang (Yangtze) River Estuary Plume in Summer as Indicated by Net Ecosystem Production Variations

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1264 ◽  
Author(s):  
Yifan Zhang ◽  
Dewang Li ◽  
Kui Wang ◽  
Bin Xue
Keyword(s):  
Mixed Layer ◽  
Yangtze River ◽  
River Estuary ◽  
Co2 Exchange ◽  
Atmospheric Co2 ◽  
Yangtze River Estuary ◽  
Biological Processes ◽  
Ecosystem Production ◽  
Near Shore ◽  
Exchange Flux

We conducted 24-h real-time monitoring of temperature, salinity, dissolved oxygen, and nutrients in the near-shore (M4-1), front (M4-8), and offshore (M4-13) regions of the 31° N section of the Changjiang (Yangtze) River estuary plume in summer. Carbon dioxide partial pressure changes caused by biological processes (pCO2bio) and net ecosystem production (NEP) were calculated using a mass balance model and used to determine the relative contribution of biological processes (including the release of CO2 from organic matter degradation by microbes and CO2 uptake by phytoplankton) to the CO2 flux in the Changjiang River estuary plume. Results show that seawater in the near-shore region is a source of atmospheric CO2, and the front and offshore regions generally serve as atmospheric CO2 sinks. In the mixed layer of the three regions, pCO2bio has an overall positive feedback effect on the air–sea CO2 exchange flux. The contribution of biological processes to the air–sea CO2 exchange flux (Cont) in the three regions changes to varying extents. From west to east, the daily means (±standard deviation) of the Cont are 32% (±40%), 34% (±216%), and 9% (±13%), respectively. In the front region, the Cont reaches values as high as 360%. Under the mixed layer, the daily means of potential Conts in the near-shore, front, and offshore regions are 34% (±43%), 8% (±13%), and 19% (±24%), respectively. The daily 24-hour means of NEP show that the near-shore region is a heterotrophic system, the front and offshore regions are autotrophic systems in the mixed layer, and all three regions are heterotrophic under the mixed layer.

Taxonomic Review of the perciform fish genus Acanthistius from the east coast of southern Africa, with description of a new species and designation of a neotype for Serranus sebastoides Castelnau, 1861

Zootaxa ◽  
2010 ◽  
Vol 2352 (1) ◽  
pp. 59 ◽  
Author(s):  
PHILLIP C. HEEMSTRA
Keyword(s):  
South Africa ◽  
New Species ◽  
South America ◽  
Southern Africa ◽  
East Coast ◽  
Valid Species ◽  
Shallow Waters ◽  
Single Specimen ◽  
Warm Temperate ◽  
A New Species

The genus Acanthistius Gill, 1862 comprises ten putative valid species occurring in shallow warm-temperate waters of the Southern Hemisphere: South America (coasts of Ecuador, Peru, Chile, Brazil, and Argentina) southern Africa (Namibia and South Africa), southern Australia, New Zealand, Lord Howe, Norfolk, Kermadec and Easter, and Sala y Gómez islands. Two species: Acanthistius sebastoides (Castelnau, 1861) and Acanthistius sp are known from shallow waters of the east coast of South Africa (Heemstra and Randall, 1986). The latter taxon, previously known from a brief description of a single specimen, is here described from 23 specimens and named Acanthistius joanae. Acanthistius sebastoides is redescribed from 13 specimens and compared with A. joanae and species of Acanthistius known from South America and Australia. A neotype is designated for Serranus sebastoides Castelnau, 1861, as the two syntypes are apparently lost.

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