Estimation of Nutrient Discharge from Fish Farming in the São Camilo River Micro-Watershed, Brazil

Abstract

Objective: Estimate the nutrient input from aquaculture in the São Camilo River micro-watershed using geotechnological tools.   Theoretical Framework: The municipalities that share the São Camilo River micro-watershed stand out in fish production. Nitrogen and phosphorus are the principal waste products from fish farming that affect water quality in rivers. Open access geotechnologies make it possible to produce maps and documents that help in the sustainable planning of the use of natural resources in river micro-watersheds.   Method: Qualitative exploratory methodology for fish production in the municipalities. Mapping of physical and natural resources and excavated ponds using geotechnologies to estimate the nutrient input from fish farming.   Results and Discussion: The São Camilo River micro-watershed has morphology and morphometry favorable to aquaculture in excavated ponds. Aquaculture production in its municipalities accounted for 4.42% of all national production. The estimated daily input for the rearing phase was 976 kg of Nitrogen and 113 kg of Phosphorus. This estimate could reach 10,950 kg of Nitrogen and 2,190 kg of Phosphorus per day of harvesting, if there is no planning among the micro-watersheds.   Research Implications: Knowledge of the need to plan the harvesting of excavated ponds among fish farmers in the micro-watershed, and the preparation of maps and characterization of the micro-watershed.   Originality/Value: This paper contributes to the development of maps and important data, such as morphometric indices and estimates of nutrient inputs, which are important for the sustainable planning of fish farming in the São Camilo River micro-watershed.