Benguela Current as a hydrological barrier for warm-water marine benthic diatom species (Bacillariophyta) off the coast of Southern Africa

Diatoms are unicellular, eukaryotic, photosynthetic microorganisms with a cell wall mineralized with silica. Marine benthic diatoms are abundant, ubiquitous and have specific ecological preferences, which make them ideal bio-indicators of their environment. Only by documenting and describing the species present on our shores will we be able to better understand the fundamental patterns and processes underpinning important ecosystem services and define how these may be altered by climate and global change. The project will test hypotheses on the biogeography and spread of diatoms from Southern Africa to the northern hemisphere (related to past climate change) and provide vital information on taxonomy (both morphological and molecular) and their ecological preferences. Samples have been collected from intertidal and subtidal rocks (epilithic diatoms), sand (episammic diatoms) and macroalgae/seaweed (epiphytic diatoms) species identifications are underway using light and scanning electron microscopy.

• Project Leader: Dr Tommy Bornman (SAEON)

• Collaborators: Przemyslaw Dabek (University of Szcecin, Poland), Prof Andrzej Witkowski (University of Szcecin, Poland) and Deon Louw (Ministry of Fisheries and Marine Resources, Namibia)

• Study Period: 2013/04/01 - ongoing