The effect of recirculating aquaculture systems on the concentrations of heavy metals in culture water and tissues of Nile tilapia Oreochromis niloticus

• Published in: Food chemistry 2011-06, Vol.126 (3), p.1001-1005
• Main Authors: Martins, Catarina I.M., Eding, Ep H., Verreth, Johan A.J.
• Format: Article
• Language: English
• Subjects: accumulation; anguilla; Aquaculture; Arsenic; bioaccumulation; Biological and medical sciences; Brackish; Fillets; Fish; fish culture; food contamination; Food industries; Fundamental and applied biological sciences. Psychology; Heavy metals; ICP-MS; ICP-OES; Iron; lake; Liver; Manganese; muscle tissues; Muscles; mykiss; Nickel; Nile tilapia; Oreochromis niloticus; recirculating aquaculture systems; Recirculation aquaculture systems (RAS); substances; Tilapia; tilapia (common name); Water exchange rates; water pollution; Water re-use systems; wild
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2010.11.108

► Concentration of As, Fe, Mn, Ni, and Zn in RAS water increases with decreasing water exchange rates. ► Accumulation in the water is not translated into accumulation in the fish liver and muscle. ► Accumulation of heavy metals is higher in the liver as compared to the muscle, except for As. ► Concentration of heavy metals in fish produced in RAS is lower than permissible safety levels for human consumption. To date, farming fish in recirculating aquaculture systems (RAS) is one of the most environmentally friendly ways of producing fish. However, with the trend towards intensification, and consequently decrease in water exchange rates, these systems may accumulate substances, such as heavy metals, in the water and fish. Inductively-coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectroscope (ICP-MS) were used to determine Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn, in the water and fish (Nile tilapia Oreochromis niloticus). Three RAS were used, differing in daily water exchange rates (30, 70 and 1500l/kgfeed/d). The concentrations of As, Fe, Mn, Ni and Zn in the water increased with decreasing water exchange rates, suggesting an accumulation of heavy metals as more water was re-used. Such accumulation in the water was, however, not translated into accumulation in the liver and muscle. Accumulation of heavy metals was always higher in the liver than in the muscle; however, As reached 1.61mg/kg wet weight in the muscle of fish farmed in RAS-70l/kgfeed/d. However, these levels are considerably lower than permissible safety levels for human consumption.