INTERFERENCE COMPETITION AMONG 2 INTERTIDAL SEAWEEDS - CHONDRUS-CRISPUS STRONGLY AFFECTS SURVIVAL OF FUCUS-EVANESCENS RECRUITS

Effects of Chondrus crispus on recruitment of Fucus were examined in o rder to test the proposition that this red turfing alga is able to exc lude fucoids from the low zone of wave-exposed shores in Nova Scotia, Canada. F. evanescens zygotes were released on experimental plots wher e Chondrus presence was manipulated. Grazers were excluded and not tre ated as an experimental factor. Initial settlement density of F. evane scens was enhanced by presence of crustose holdfasts and canopy of Cho ndrus, and reduced on sandblasted bare rock. However, subsequent survi val and growth of fucoid germlings were heavily suppressed when Chondr us was present. A fucoid canopy established only on bare rock.