Browsing by Author "Gibbons, Mark J."
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Records of ctenophores from South Africa
Gibbons, Mark J.; Haddock, Steven H.D.; Matsumoto, George I. (PeerJ, 2021)Although ctenophores can be conspicuous components of the plankton in coastal marine ecosystems, only six species have been formally described from around South Africa. Using photographs from local community scientists, ... -
Reviewing evidence of marine ecosystem change off South Africa
Moloney, C. L.; Fennessy, S. T.; Gibbons, Mark J.; Roychoudhury, A.; Shillington, F. A.; von der Heyden, B. P.; Watermeyer, K. (National Inquiry Services Centre, 2013)Recent changes have been observed in South African marine ecosystems. The main pressures on these ecosystems are fishing, climate change, pollution, ocean acidification and mining. The best long-term datasets are for trends ... -
A revision of the genus Strongylodesma Lévi (Porifera: Demospongiae: Latrunculiidae) with descriptions of four new species
Samaai, Toufiek; Gibbons, Mark J.; Kelly, Michelle (Cambridge University Press, 2009)The sponge genus Strongylodesma is reviewed and redefined, and now accommodates eight closely related species. The type species of Strongylodesma Le´vi is redescribed and an additional two new species are described from ... -
Self-maintaining or continuously refreshed? The genetic structure of Euphausia lucens populations in the Benguela upwelling ecosystem
Harkins, Gordon William; D'Amato, Maria Eugenia; Gibbons, Mark J. (Oxford University Press, 2013)Populations of Euphausia lucens over the shelf of the southern Benguela upwelling region could be self-maintaining. Alternatively, they could be continually refreshed by expatriates from the SW Atlantic that enter the ... -
Self-maintaining or continuously refreshed? The genetic structure of Euphausia lucens populations in the Benguela upwelling ecosystem
Harkins, Gordon W.; D’amato, Maria E.; Gibbons, Mark J. (Oxford University Press, 2013)Populations of Euphausia lucens over the shelf of the southern Benguela upwelling region could be self-maintaining. Alternatively, they could be continually refreshed by expatriates from the SWAtlantic that enter the ... -
Siphonophores from surface waters of the Colombian Pacific Ocean
Uribe-Palomino, Julian; López, Raúl; Gibbons, Mark J.; Gusmão, Felipe; Richardson, Anthony J. (Cambridge University Press, 2018)Siphonophores are colonial hydrozoans that feed on zooplankton including fish larvae, and occur throughout the world’s oceans from surface waters to ocean depths. Here we describe the composition of hyponeustonic siphonophores ... -
Towards the acoustic estimation of jellyfish abundance
Brierley, Andrew S.; Boyer, David C.; Axelson, Bjorn Erik; Lynam, Christopher P.; Sparks, Conrad A.J.; Boyer, Helen; Gibbons, Mark J. (Inter-Research, 2005)Acoustic target strengths (TSs) of the 2 most common large medusae, Chrysaora hysoscella and Aequorea aequorea, in the northern Benguela (off Namibia) have previously been estimated (at 18, 38 and 120 kHz) from acoustic ... -
Trophic ecology of carnivorous zooplankton in the Benguela
Gibbons, Mark J.; Stuart, V.; Verheye, H.M. (NISC and Taylor & Francis, 1992)Carnivorous zooplankton in the Benguela system have tended to be ignored by all but early taxonomists and a handful of recent researchers. An attempt is made here to address the importance of carnivores in this system but, ... -
Two new nematode species from Saldanha Bay, South Africa: Perepsilonema benguelae sp. nov. and Leptepsilonema saldanha sp. nov. (Nematoda, Epsilonematidae)
Gibbons, Mark J.; Hendricks, Martin G.J. (Magnolia Press, 2010)Perepsilonema benguelae sp. nov. and Leptepsilonema saldanhae sp. nov. are described and illustrated from coarse sand sediments in Saldanha Bay, along the west coast of South Africa. Perepsilonema benguelae sp. nov. is ... -
Video observations on the habitat association of demersal nekton in the mid-shelf benthic environment off the Orange River mouth
Sulaiman, A.; Hissman, K.; Schauer, J.; Wickens, P.A.; McMillan, I.; Gibbons, Mark J. (NISC and Taylor & Francis, 2000)A semi-quantitative assessment is made of the animals observed in archived videotapes taken from the research submersible Jago, during diamond mining and exploratory surveys off the mouth of the Orange River on the west ...