Influence of the frontal system on the cross-shelf distribution ofEuphausia lucensandEuphausia recurva(Euphausiacea) in the southern Benguela system

Abstract

The distribution of the euphausiids Euphausia lucens and E. recurva along a transect of stations off the mouth of the Olifants River, on the west coast of South Africa, was investigated to examine interchange processes through the frontal system. Longshore currents dominated the study area and confirmed the existence of the shelf-break frontal system. Densities of E. lucens larvae and adults declined sharply seawards of the front, whereas E. recurva were distributed farther offshore at the outer margin of the front. The front allowed little net cross-shelf transport of euphausiid reproductive products and maintained the species discreteness of the two euphausiids.