Water Quality and Effluents Generated during Rainbow Trout Culture in a Raceway System

• Autor(a) principal: Ana Paula Monschau Funck
• Data de Publicação: 2019
• Outros Autores: José Antonio Beirão Simões, Marina Guimarães Ferreira, Edenilce de Fátima Ferreira Martins, Fabiano Aurélio da Silva Oliveira, Luciano Dos Santos Rodrigues, Marília Martins Melo, Kleber Campos Miranda Filho
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFMG
• Texto Completo: http://dx.doi.org/10.26717/BJSTR.2019.16.002921; http://hdl.handle.net/1843/67442; https://orcid.org/0000-0003-0555-8305
• topic: Qualidade da água em aquacultura; Aquicultura; Piscicultura; Truticultura; Oceanografia; Qualidade da água; Aquicultura; Pesqueiros

The objective of this study was to evaluate the quality of water and the polluting load generated by two commercial trout farms (A e B) in a raceway system during the years of 2013, 2014 and 2015 in the rainy season (October to March) and dry season (April to September). Six collection points demarcated in the trout farm A, with total 84 samples and 9 collection points in trout farm B, with total 126 samples. The collection points defined as follows: tributary, effluent, upstream and downstream in the two trout farms. Biochemical oxygen demand (BOD), dissolved oxygen (OD), ammoniacal nitrogen (NH3 +NH4+ ), nitrite (NO2- ), nitrate (NO3- ), phosphate (PO43-), alkalinity, turbidity and thermotolerant coliforms were determined according to the protocol described in Standard Methods Water and Wastewater (APHA, 2008). Analyzes of temperature, pH, electrical conductivity (EC), total dissolved solids (TDS) and salinity performed in situ. The Physiochemical variables evaluated between the rainy and dry seasons, in the A and B trout farms, differed for EC, BOD, NH3 +NH4+ , PO43-, TDS, temperature and turbidity. In trout farm B, chloride and pH levels also showed significant differences. About the collection points, the two trout farms presented differences for TDS. The trout farm A showed difference for BOD and trout farm B, for alkalinity and EC. There was an interaction effect between collection points and rainfall and dry seasons as a source of variation in the two trout farms, with differences observed for the variables EC, TDS and temperature, but there were also differences in trout farm A for BOD and NH3 +NH4+ , in the trout farm B, the alkalinity presented significant differences (p<0.05). In the study with thermotolerant coliforms in the trout farm A differences were observed between rainy and dry seasons, but without differences between the collection points. In trout farm B there was no difference between rainy and dry seasons. Regarding the presence of Escherichia coli bacteria, no difference observed in trout farm A, only in trout farm B there was difference. It was demonstrated in this study that the physicochemical and microbiological alterations evaluated are within the standards of comfort for the cultivated species and in accordance with the effluent release standard of the Brazilian legislation, showing minimal impact to the receiving water bodies.