Krill occupy a central role in oceanic food webs as consumers as well as producers. They are a major source of nutrition to fish, birds, seals, and whales. A change in a krill population may thus have dramatic impacts on ecosystems. Within the zooplankton community, Euphausia hanseni belongs to one of the most abundant krill species of the Northern Benguela Current (Olivar and Barange 1990; Barange et al. 1991). The aim of this study was to investigate specific adaptations within the life strategy of E. hanseni. The animals rely on upwelling pulses that lead to rich plankton patches as a food source. The Benguela Current system is a nutritionally poly-pulsed and stratified environment. During late austral summer, the region is typically characterized by minimum upwelling (Hagen et al. 2001) which goes along with short periods of food deprivation. The following questions shall be answered: How does E. hanseni metabolically adjust during a period of starvation, i.e. between upwelling pulses? Are there metabolic differences in krill influenced by different water masses (cold Benguela Current and warm Angola Current)?