Temporal patterns of physicochemical and bacteria profiles of static aquaculture systems: insights into health hazards for fish and the public

Abstract

Knowledge on water quality in static aquaculture systems is crucial to gain understanding of health threats to fish or aquaculture personnel. In the present study, we investigated the temporal profiles of the bacteriological profiles and physicochemical status of static water aquaculture systems (earthen ponds and concrete tanks). All physicochemical parameters measured were within the optimum recommendation. Following microbial analyses in earthen pond water, the TVC and TCC showed temporal variations with concentration increasing with sampling time, however, FCC fluctuated, and 8 bacteria groups were isolated from both rearing enclosures. In which Gram (-) bacteria showed dominance, with 5 Gram negative (Escherichia coli, Proteus spp, Serratia spp, Enterobacter spp and Pseudomonas spp) and 3 Gram positive (Staphylococcus spp, Streptococcus spp, and Bacillus spp) encountered. From earthen pond water, the following microbial occurrences were reported: Staphylococcus spp (20%), Streptococcus spp (12%) Proteus spp (8%) Enterobacter spp (20%) Serratia spp (16%), Bacillus spp (9%), Escherichia coli (8%), Pseudomonas spp (7%). While Staphylococcus spp (18%), Streptococcus spp (16%), Proteus spp (8%), Enterobacter spp (22%), Serratia spp (8%), Bacillus spp (15%), Escherichia coli (8%), Pseudomonas spp (6%) occurred in concrete water. Taken together, although the physicochemical condition raised no well-fare concern, however, the bacteriological profile during this investigation showed potential health risk in static water aquaculture condition or to adjacent aquatic environment from end of production-discharge.