Fish species assemblages on the continental shelf and upper slope off Ghana
Using two-way indicator species analysis and detrended correspondence analysis, species on the continental shelf and upper slope of Ghana are assigned to six assemblages. The assemblages are comparable to those described thirty years ago from recurrent species analysis and for the whole Gulf of Guinea. The structure of the assemblages is determined primarily by depth and type of sediment on the seabed, the latter of which is more important when considering a compressed depth gradient. There are clear faunal discontinuities at 30 m, 100 m and 200 m deep. The dynamics of the assemblages are influenced by the physicochemical parameters of regional and local water masses, primarily temperature, salinity and dissolved oxygen which are periodically modified by the seasonal coastal upwelling that occurs in the area.
Increased fishing activity, environmental forcing and the proliferation of Balistes capriscus singly or conjointly influenced the observed changes in the composition and relative importance of species in the assemblages.
Read full paper https://doi.org/10.1016/S1570-0461(02)80036-2