The structure of demersal assemblages off Namibia in relation to abiotic factors

Abstract

Groundfish surveys carried out between October 1992 and October 1996 were used to describe the demersal assemblages of the northern Benguela along the Namibian coast. Multivariate analyses indicated a clear separation between shelf and slope habitats, which were divided into three and two assemblages respectively. These divisions were distinct, with clear distributional boundaries separating them. Species determining the structure of these divisions and subdivisions and their relative abundances were identified. Depth, bottom temperature, bottom salinity and dissolved oxygen were all significantly correlated with the spatial distribution of the assemblages. Minor changes or shifts in the distribution of assemblages were observed over the study period, although patterns of species associations remained relatively constant.

Keywords: community, demersal, environment, fishery, Namibia, trawling

African Journal of Marine Science 2001, 23: 397–417