<b>Nutrient and trophic state variations in continuous water flow fish ponds</b> - DOI: 10.4025/actascianimsci.v27i3.1218

Abstract

This experiment evaluated trophic state and increase in nutrient concentrations in sequential fish ponds in short-term periods. Six semi-intensive fish ponds where studied and received effluents from other parallel ponds. The variables determined were: total phosphorus, orthophosphate, ammonia, nitrate, nitrite, chlorophyll-a, lead, cadmium, copper, zinc, manganese, nickel, chromium, calcium, iron, potassium and magnesium, in addition to the trophic state of the fish ponds. Water samples were collected in the well and at the inlet of each fish pond in rainy and dry periods. An increase in the trophic degree was found from the first to the last fishpond, and the sequential distribution provided a gradual increase in the concentrations of metals and chlorophyll-a. The results achieved in the present study indicate the need of environmental management practices through effluent deviation from parallel tanks