Abstract
The density of the 40 most abundant demersal fish species off Namibia is inversely scaled to their average length, similar to the scaling of mortality to fish length. However, the density of individual fish species is, on average, scaled to the −2 power of average fish length in the aggregates, indicating that biomass increases (slope > −3) during the growth of most species examined. These findings indicate that size structure of these fish populations is primarily determined by mortality.