Fast food : the transport of particulate organic matter over an upwelling event on the west coast of southern Africa

Differences in transport, composition and supply of particulate organic matter (POM), as a food source for coastal consumers, were investigated between an exposed headland (Cape Columbine) and a sheltered bay (Elandsbaai) in the southern Benguela. Physical data, in agreement with previous studies, showed that Cape Columbine is situated within an upwelling center and Elandsbaai within an upwelling shadow. Three distinct oceanographic conditions, upwelling, relaxation and downwelling, were discemable from wind, current and temperature data at each site. Upwelling was most prevalent at Cape Columbine in contrast to relaxation at Elandsbaai. Significant differences (P < 0.00001) in chlorophyll a concentration, quantities of organic carbon and % kelp-derived carbon were found between the two sites. In addition, significant differences (P < 0.0001) in chlorophyll a concentration, quantities of organic carbon and % kelp-derived carbon were found between the different oceanographic conditions: upwelling, relaxation and downwelling. A significant interaction (P < 0.00001) for % kelp-derived carbon was found between site and oceanographic conditions. Tests within study sites revealed significantly higher chlorophyll a concentrations in the euphotic zone, as expected. Furthermore, chlorophyll a concentrations showed a significant decrease with distance offshore at Elandsbaai. Percentage contribution of kelp-derived carbon (max = 36%) to POM was lower than predicted and surprisingly lower than values reported in previous works (77%). No stratification of kelp-derived matter or organic carbon was observed in the water column at both sites. It is likely that sampling stations were too shallow i.e. water column was well mixed as a results of nearshore turbulence. In terms of food supply to coastal consumers, upwelling episodes at Cape Columbine resulted in significantly high import of kelp matter into the nearshore water column. In contrast, phytoplankton, constituted the primary food source for both sites during relaxation and downwelling episodes. It is clear that different oceanographic conditions between an exposed headland and a sheltered bay have profound implications regarding the transport, composition and supply of POM, as a source of food to coastal communities

Taxonomy, systematics and biogeography of South African Cirripedia (Thoracica)

Includes bibliographical references.The South African Cirripedia (Thoracica) are reviewed for the first time in 88 years, since that of Barnard (1924). Data collection consisted of records from the South African Museum, previously published literature, and specimens collected in the field. The current state of knowledge of the taxon in South Africa has been considerably raised. Thirteen new records are added to the fauna, of Which 84.6% are cosmopolitan and 15.4% introduced species. This raises the total number of South African Cirripedia (Thoracica) to 86, of which 64.06% are cosmopolitan, 11.24% introduced and 24.7% endemic. Excluded from this, are three unknown species, which are likely to be new to science. Descriptions of these species will be undertaken outside of this thesis and published; however, they were classified as endemic and included in the analyses presented in Chapter three. Eleven of the new fauna can be described as "offshore benthic" and represent well known deep-water taxa

Giants and titans: First records of the invasive acorn barnacles Megabalanus tintinnabulum (Linnaeus, 1758) and Megabalanus coccopoma (Darwin, 1854) on intertidal rocky shores of South Africa

During intertidal rocky shore surveys on the east coast of South Africa in 2018, the non-indigenous giant purple barnacle Megabalanus tintinnabulum (Linnaeus, 1758), a well-known fouling and globally-invasive species, was discovered. This motivated a survey of the entire South African east coast at 31 rocky shore sites, which confirmed that breeding populations of this barnacle have been established in most wave-exposed low-shore intertidal habitats between the Mozambique border and Mkambati Nature Reserve and that its current South African distribution spans 725 km of coastline. Another non-indigenous and common fouling species, the titan acorn barnacle M. coccopoma (Darwin, 1854), was discovered at three of the sites, its local distribution spanning 370 km of coastline. While currently uncommon, this species is known to reach high densities in other non-native regions. Both Megabalanus species are large and conspicuous and were not found during extensive surveys in the 1990s and early 2000s, suggesting that their introduction and spread occurred within the past two decades

Additions to the barnacle (Crustacea: Cirripedia) fauna of South Africa

The purpose of this paper is to document recent additions to the South African barnacle (Cirripedia) fauna. New species records were obtained by examining accumulated collections of unidentified material in the Iziko South African Museum, as well as via material collected directly by the authors. Fourteen species, none of which are new to science, are added to the known fauna, raising the total number of barnacle species recorded from South Africa by over 20%, from 69 to 83 species. Ten of the additional species are offshore benthic forms and represent deep-water taxa whose ranges are extended into South African waters. The remaining four are coastal inshore or surface-dwelling species, of which three are considered recent anthropogenic introductions. The large number of additions to the fauna can be attributed to a long absence of taxonomic expertise on this group in the region and consequent accumulation of unidentified samples. A high proportion of the deep-water samples examined contained previously unreported species, suggesting that additional sampling of hard abyssal substrata in the region is certain to yield yet more new cirripede records.Keywords: barnacles, biodiversity, distribution, introduced species, rang