Abstract
Intertidal bryozoan algal associations were studied along the southern California coastline between La Jolla and Santa Barbara and on Santa Catalina Island. Seventeen species of bryozoans were identified incrusting 6 species of Chlorophyta, 1 3 species of Phaeophyta and 43 species of Rhodophyta. Collections were made at 15 southern California stations; herbarium specimens of algae from 32 southern California stations were examined. Factors affecting bryozoan preference for an algal substrate were: (1) the location of algae in the littoral region; (2) availability of various substrata; (3) production of anti-fouling substances by brown and possibly red algae.