Rv. Dingle, CONTINENTAL-SHELF UPWELLING AND BENTHIC OSTRACODA IN THE BENGUELA SYSTEM (SOUTHEASTERN ATLANTIC-OCEAN), Marine geology, 122(3), 1995, pp. 207-225
The distribution of benthic Ostracoda (micro-crustacea) on the contine
ntal shelf off southwestern Africa is controlled by sea-floor physical
and chemical parameters, which in turn can be correlated with the pos
itions of quasi-permanent upwelling cells of the Benguela System. The
linkage between benthic and surface physico-chemical environments (and
consequently between benthos and surface parameters) is not direct, h
owever, being modulated by equatorward motion in the upper water colum
n, benthic poleward water-motion, fluvial input and cross-shelf advect
ion of off-shelf water. These phenomena, and in particular the intensi
ty of surface upwelling, show a sharp distinction about approximately
27 S, so that the ostracod faunas in the Northern Benguela Region are
relatively sparse and dominated by Palmoconcha walvisbaiensis, (Hartma
nn) and Cytherella namibensis, Dingle, while in the Southern Benguela
Region the faunas are more diverse and dominated by Pseudokeijella lep
ralioides, (Brady) and Ruggieria cytheropteroides, (Brady). When minor
taxa are also considered, each cell in the Benguela upwelling system
is shown to be associated with a unique ostracod fauna which can be re
lated to its in particular environmental characteristics.