The community structure of foulers on various substrata in different regions of the Visakhapatnam harbour was analyzed. The results indicate that community composition differed from season to season and station to station within each season (2 to 17). Species richness at various stations during each season was found to be generally higher (10 to 17) in the outer harbour than in the inner harbour (2 to 13). The diversity and evenness indices were high and dominance indices low at almost all the stations during premonsoon season relative to postmonsoon season in the outer harbour whereas these indices remained the same during both the seasons in the inner harbour. Reasons for such variations are discussed. Fouling biomass among the stations ranged from 2.3 to 11.0 kg.m-2 during postmonsoon season and 1.5 to 8.8 kg.m-2 during premonsoon season. The foulers Dynamenella dianae, Acanthochitona mahensis and Isognomon legumen formed new records to Visakhapatnam harbour and Siphonaria kurracheensis to the east coast of India.

Harbour structures, fouling organisms, community composition, diversity index, Visakhapatnam harbour