Epiphytic patterns of macroalgal assemblages on Cystoseira species (Fucales, Phaeophyta) in the east coast of Attica (Aegean Sea, Greece)

Epiphytic macroalgal assemblages growing on Cystoseira species were examine d at typical oligotrophic and eutrophic sites of the east coast of Attica ( Aegean Sea, Greece) from November 1995 to September 1996. The epiphytic pat terns of C. spinosa Sauvageau thriving in the oligotrophic area of Dikastik a and of C. compressa (Esper) Gerloff & Nizzamudin growing in the eutrophic environment of Avlida, were compared through a cross-transplantation exper iment. Seasonality effects on epiphytic assemblages were observed. The spec ies composition was exclusive for each locality, reflecting differences in the trophic status of the two sites. No specific pattern of epiphytes' dist ribution was found on the hosts. The prolific epiphytic growth in the oligo trophic site resulted in a reduction of the photosynthetic tissue of both h osts (C. spinosa and the transplanted C. compressa) and the survivorship of host plants was not negatively affected by the physical drag caused by the high epiphyte densities. Cystoseira spinosa survived in oligotrophic condi tions despite its heavy epiphytic load. C. compressa was also able to cope with the adverse epiphytic influence in the eutrophic conditions of Avlida; although being perennial, it sheds parts of its stipe and branches before the resting period and sprouts prior to other algae at the beginning of spr ing.