THE MARINE-ALGAE OF HLULEKA (TRANSKEI) AND THE WARM TEMPERATE - SUBTROPICAL TRANSITION ON THE EAST-COAST OF SOUTHERN-AFRICA

The marine flora of the transition region between the warm temperate south coast and sub-tropical east coast of southern Africa is very poorly documented. The seaweeds of Hluleka Nature Reserve, centrally placed along this transition, are described. 178 species (120 rhodophytes, 33 chlorophytes and 25 phaeophytes) are recorded, including 28 new records for the region, and a new combination, Tiffaniella schmitziana (Barton) nov. comb. [Spermothamnion schmitzianum]. A biogeographical analysis of those species whose distribution is sufficiently known reveals that 65% are warm water species, also occurring in tropical seas. Hluleka is thus towards the warmer end of the transition, and the major discontinuity is sharply defined, occurring in the ca 130 km of coastline between Hluleka and the mouth of the Kei River. It is probable that a rapid temperature gradient along this stretch of coast (change of 2.degree.C in annual mean) is responsible for the discontinuity.