Population dynamics of Northern krill (Meganyctiphanes norvegica Sars)

This chapter reviews the short- and long-term changes in the size and age composition of Northern krill (Meganyctiphanes norvegica) populations and the environmental processes influencing those changes. It examines how populations of this species are affected by rates of reproductive output and mortality, and the effects of development, immigration and dispersion on population structure. This review also takes account of the many behavioural features that directly or indirectly influence M. norvegica population dynamics, such as swarming behaviour, diel vertical migration and diverse feeding strategies. What becomes evident is that M. norvegica shows a wide variability in population size-structure over the species extensive distributional range. Nevertheless, there are limits to this variability, as a result of the common life-cycle pattern.