Studies of marine epiphytic algae, Calvi, Corsica. III. Variations in the populations of epiphytic Bangiophyceae

Variations in the populations of Bangiophyceae (Rhodophyta) epiphytic on Cladophora prolifera and Stypocaulon scoparium were monitored qualitatively and quantitatively for two years (1981/82 and 1987/88) in nine stations with constrasting water quality in the area of Calvi (Corsica). The development of Chroodactylon ornatum was temperature dependent and showed its maximum density during the summer. The development of the other Bangiophyceae (Erythrocladia irregularis, Erythrotrichia camea, Goniotrichum alsidii, G. cornu-cewi) was correlated to the water quality in that their density increased towards the sewage discharge near to the town of Calvi. A general increase in epiphytism by Bangiophyceae between 1981 and 1988 seems to indicate an increased degree of eutrophication in the bay of Calvi.