Ecology of fouling bryozoans at Visakhapatnam harbour

Abstract

Twelve species of bryozoans occur in the fouling communities at Visakhapatnam Harbour, of which the encrusting cheilostome-Electra bengalensis (Stoliczka) is by far the most common. The horizontal distribution of bryozoans at four selected stations in the harbour is recorded. Quantitative data on the seasonal abundance and settling rates of E. bengalensis and some of the prevailing hydrographical conditions, i.e. temperature, salinity and turbidity data, are given for one year (December 1966 to November 1967). The observations indicate that E. bengalensts is a continuous breeder and also a fast growing species. The influence of temperature and salinity on its breeding and abundance is discussed. While only 12 species of bryozoans occur in the harbour, the number of species occurring in the nearby foreshore localities at Visakhapatnam ranges from 20 to 34. The effect of some factors (pollution, salinity, silting larval type and fouling) which may influence the distribution of bryozoans is discussed.