Nutrient cycling enhancement in intensive-extensive aquaculture through C/N ratio manipulation and periphyton support

Abstract

The external carbon source and the installation of periphyton structures were applied in combined intensive-extensive aquaculture to test their efficiency of nutrient utilization to support clean and efficient fish production. Two aquaculture systems were tested, with one additionally treated with methanol as a source of carbohydrates for microbial activity stimulation and an additional area for periphyton installed. Each system was composed of fish tanks with intensively reared sturgeon and one extensive pond stocked with common carp in polyculture. The water from intensive fish production was discharged into the fish pond, to serve as a nutrient source for primary production in the pond.Obtained data revealed that applied manipulations enhanced microorganism development and pond productivity. The results of the research show that applied moderate, nature-based upgrade in aquaculture system may allow for more efficient and cost-effective treatment of wastewater from intensive aquaculture.