Microbiological monitoring of Castellammare Gulf (TP) waters for their suitability in marine aquaculture

A three year investigation into the microbiological conditions of the waters of the Gulf of Castellammare (TP) was carried out in order to evaluate the possible utilization of this area as an aquaculture site. Analysis of a total of 168 samples was aimed at estimating the quantitative distribution of total and fecal coliforms, enterococci and halophilic vibrios. The qualitative distribution of Vibrio species was also studied with particular reference to potentially pathogenic species. Coliforms showed the highest densities (102-103CFU/100 ml) in November 1993 at the coastal stations and mostly negative values during the subsequent samplings; in contrast, halophilic vibrios prevailed in the warm months. V. alginolyticus and V. fluvialis prevailed respectively among the Vibrio population grown at 35 and 24°C, grouped in 13 and in 4 clusters at similarity levels of 81-96%. Quantitative data demonstrate the presence of low levels of microbial contamination, which suggests the general suitability of the area for fish farming.