Thermocline off the Coast of Tropical West Africa

Abstract

RECENTLY, Salzen¹ has shown that there is a marked difference with depth in the species composition of the demersal fish fauna off Tema in Ghana. He found that there was a distinct change from euryhaline and eurythermal species in the shallow inshore water, to red and brown marine species below 10 fathoms. As the same change in species had been observed by Postel² working off French Guinea, Salzen suggested that the results for Tema might be typical of a great deal of the West African shelf in the dry season. The results (unpublished) of an extensive, though not detailed, hydro-graphic survey of the region, from Dakar to the Cameroons, made during 1952, tend to support such a generalization, and pose the question as to whether the thermocline might be partly responsible for determining the distribution of the inshore fish fauna.