scholarly journals Diel variation in the vertical distribution of some common zooplankton species off the west coast of South Africa

1984 ◽  
Vol 2 (1) ◽  
pp. 71-80 ◽  
Author(s):  
S. C. Pillar
Keyword(s):  
South Africa ◽  
Vertical Distribution ◽  
West Coast ◽  
Diel Variation ◽  
Zooplankton Species ◽  
The West ◽  
The Vertical Distribution

The Annual Reproductive Patterns of Bathyporeia Pilosa and Bathyporeia Pelagica [Crustacea: Amphipoda]

1970 ◽  
Vol 50 (2) ◽  
pp. 475-488 ◽  
Author(s):  
J. D. Fish ◽  
G. S. Preece
Keyword(s):  
Vertical Distribution ◽  
West Coast ◽  
Sandy Beach ◽  
Present Report ◽  
Sandy Beaches ◽  
Annual Reproductive Cycle ◽  
The West ◽  
Reproductive Patterns ◽  
Reproductive Cycles ◽  
The Vertical Distribution

The genus Bathyporeia has featured in many reports on the ecology of sandy beaches, yet little is known of the annual reproductive cycles of the species in British waters. Watkin (1938,1939a, b, 1941, 1942) has studied the taxonomy and aspects of the ecology of the genus, and more recently Salvat (1967) has described the annual reproductive cycle of B. pilosa Lindstrom, B. pelagica (Bate), B. sarsi Watkin and B. guilliamsonia (Bate) on the west coast of France. The present report is the result of an investigation into the vertical distribution and annual reproductive patterns of B. pilosa and B. pelagica on a sandy beach at Ynyslas, Cardiganshire. Whilst enabling comparisons to be made with Salvat's data, this study also forms the basis for an investigation into the ecophysiological complex of B. pilosa and B. pelagica.

Submersible observations on the daytime vertical distribution of Aequorea ?forskalea off the west coast of southern Africa

2005 ◽  
Vol 85 (3) ◽  
pp. 519-522 ◽  
Author(s):  
Conrad Sparks ◽  
Andrew S. Brierley ◽  
Emmanuelle Buecher ◽  
Dave Boyer ◽  
Bjøern Axelsen ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Southern Africa ◽  
West Coast ◽  
Sea Surface ◽  
The West ◽  
Spatial Overlap ◽  
The Mean ◽  
The Vertical Distribution

The vertical distribution of the hydromedusa Aequorea ?forskalea was investigated using observations from the research submersible ‘Jago’ collected during 36 dives off the west coast of southern Africa during November 1997 and April 1999. The mean population depth of Aequorea ?forskalea deepened with increasing sea surface temperature. We suggest that this behaviour enables individuals to avoid offshore advection, to minimize spatial overlap with other large medusae and to maintain their position over the middle of the shelf.

Seasonal occurrence and diel calling behaviour of Antarctic blue whales and fin whales in relation to environmental conditions off the west coast of South Africa

2019 ◽  
Vol 190 ◽  
pp. 25-39 ◽  
Author(s):  
Fannie W. Shabangu ◽  
Ken P. Findlay ◽  
Dawit Yemane ◽  
Kathleen M. Stafford ◽  
Marcel van den Berg ◽  
...  
Keyword(s):  
South Africa ◽  
Environmental Conditions ◽  
West Coast ◽  
Seasonal Occurrence ◽  
The West ◽  
Calling Behaviour ◽  
Fin Whales ◽  
Blue Whales

scholarly journals The vertical distribution of biomass burning pollution over tropical South America from aircraft in situ measurements during SAMBBA

2019 ◽  
Vol 19 (9) ◽  
pp. 5771-5790 ◽  
Author(s):  
Eoghan Darbyshire ◽  
William T. Morgan ◽  
James D. Allan ◽  
Dantong Liu ◽  
Michael J. Flynn ◽  
...  
Keyword(s):  
Air Quality ◽  
South America ◽  
Vertical Distribution ◽  
Biomass Burning ◽  
Mixing Layer ◽  
Free Troposphere ◽  
The West ◽  
The Vertical Distribution ◽  
Tropical South America

Abstract. We examine processes driving the vertical distribution of biomass burning pollution following an integrated analysis of over 200 pollutant and meteorological profiles measured in situ during the South AMerican Biomass Burning Analysis (SAMBBA) field experiment. This study will aid future work examining the impact of biomass burning on weather, climate and air quality. During the dry season there were significant contrasts in the composition and vertical distribution of haze between western and eastern regions of tropical South America. Owing to an active or residual convective mixing layer, the aerosol abundance was similar from the surface to ∼1.5 km in the west and ∼3 km in the east. Black carbon mass loadings were double as much in the east (1.7 µg m−3) than the west (0.85 µg m−3), but aerosol scattering coefficients at 550 nm were similar (∼120 Mm−1), as too were CO near-surface concentrations (310–340 ppb). We attribute these contrasts to the more flaming combustion of Cerrado fires in the east and more smouldering combustion of deforestation and pasture fires in the west. Horizontal wind shear was important in inhibiting mixed layer growth and plume rise, in addition to advecting pollutants from the Cerrado regions into the remote tropical forest of central Amazonia. Thin layers above the mixing layer indicate the roles of both plume injection and shallow moist convection in delivering pollution to the lower free troposphere. However, detrainment of large smoke plumes into the upper free troposphere was very infrequently observed. Our results reiterate that thermodynamics control the pollutant vertical distribution and thus point to the need for correct model representation so that the spatial distribution and vertical structure of biomass burning smoke is captured. We observed an increase of aerosol abundance relative to CO with altitude both in the background haze and plume enhancement ratios. It is unlikely associated with thermodynamic partitioning, aerosol deposition or local non-fire sources. We speculate it may be linked to long-range transport from West Africa or fire combustion efficiency coupled to plume injection height. Further enquiry is required to explain the phenomenon and explore impacts on regional climate and air quality.

scholarly journals Shark–Cetacean trophic interaction, Duinefontein, Koeberg, (5 Ma), South Africa

2015 ◽  
Vol Volume 111 (Number 11/12) ◽  
Author(s):  
Romala Govender ◽  
Keyword(s):  
South Africa ◽  
Cause Of Death ◽  
West Coast ◽  
Trophic Interaction ◽  
The West ◽  
Carcharodon Carcharias ◽  
Inverted Position ◽  
Bite Marks ◽  
Shark Teeth ◽  
Long Time

Abstract This study forms part of a larger project to reconstruct the Mio-Pliocene marine palaeoenvironment along South Africa’s west coast. It documents the shark–cetacean trophic interaction during the Zanclean (5 Ma) at Duinefontein (Koeberg). The damage described on the fragmentary cetacean bones was compared with similar damage observed on fossils from Langebaanweg, a Mio-Pliocene site on the west coast of South Africa, and data present in the literature. This comparison showed that the damage was the result of shark bites. The state of preservation makes it difficult to determine if the shark bite marks were the cause of death or as a result of scavenging. The presence of the bite marks on the bone would, however, indicate some degree of skeletonisation. Bite marks on some cranial fragments would suggest that the cetacean’s body was in an inverted position typical of a floating carcass. The preservation of the material suggests that the bones were exposed to wave action resulting in their fragmentation as well as abrasion, polishing and rolling. It also suggests that the cetacean skeletons were exposed for a long time prior to burial. The morphology of the bites suggests that the damage was inflicted by sharks with serrated and unserrated teeth. Shark teeth collected from the deposit include megalodon (Carcharodon megalodon), white (Carcharodon carcharias) as well as mako (Isurus sp. and Cosmopolitodus hastalis) sharks, making these sharks the most likely predators/scavengers.

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