Biomass spectra in benthic fish assemblages in the Benguela System

B~ornass spectra in the different benthic fish assemblages at depths between 100 and 800 m off the coast of Namibia were studied over a p e r ~o d of 3 yr These assemblages were located in areas spanning active upwelling centres on the shelf and zones of lower productiv~ty on the lower slope.The slopes of the curves for the normallzed size distributions were related to zonal productivity and abundance of the smallest slze classes.In the main upwelling centre, in which abundance of small specimens was h ~g h e r and comrnunlty diversity lower, biomass clearly dropped off with increasing size; teleost fishes and m~d-level predators (which prey on euphausiids and other pelagic crustaceans) predominated In the less productive zone, where the biomass of small specimens was very low and communlty divers~ty very h ~g h , biornass increased or at least tended to remaln constant with size and elasrnobranchs and apex predators (which prey on fish and cephalopods) were most abundant.