GROWTH OF INDICATOR BACTERIA IN A FLOW-THROUGH AQUACULTURE FACILITY

A flow-through commercial catfish growout operation was found to have high levels of fecal coliforms (FC) in the discharge. Analyses by acad emic, commercial and regulatory agency laboratories were conducted thr ough the system over a five month period in 1991 for various indicator bacteria groups as well as potential pathogens with highly variable r esults. Biochemical differentiation of FC showed most to have been Kle bsiella pneumoniae, K. oxytoca, E. coli and Citrobacter freundii. Duri ng production many of the effluent FC levels exceeded state surface wa ter criteria for contact and non-contact recreation of 200/100 ml. Gen erally, great diversity in results were shown between laboratories dep ending on their analytical specialty and whether they were responding to requests to show the FC populations to have been fecal in origin, o r potential pathogens.