Water quality of small fish ponds associated with swine culture.

Abstract

The water quality of fish ponds with tilapia (Oreochromis niloticus) culture, associated with swine culture activities in a farm in Frutal, Brazil, was evaluated. Water samples were retrieved monthly, during 9 months, in three fish ponds with inflows and outflows (6 sites) to quantify limnological and microbiological variables, such as dissolved oxygen, pH, electrical conductivity, total dissolved solids, temperature, ammonia, nitrate, nitrite, total phosphorus, orthophosphates and thermotolerant coliforms. Results from different sample sites were statistically analyzed, according to data distribution for each variable. Three variables (dissolved oxygen, total phosphorus and thermotolerant coliforms) failed to comply with standards recommended by the Brazilian legislation. Since adjacent swine farms near the two ponds impacted water quality with regard to the above parameters, a treatment system in Pond 2 or a reduction of swine activity in the ponds is recommended to maintain adequate water quality for fish farming.