Copper use and accumulation in catfish culture in the Mekong Delta, Vietnam

• Published in: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering Toxic/hazardous substances & environmental engineering, 2014-01, Vol.49 (2), p.187-192
• Main Authors: Marcussen, Helle, Løjmand, Helle, Dalsgaard, Anders, Hai, Dao M., Holm, Peter E.
• Format: Article
• Language: English
• Subjects: Animals; Applied sciences; Aquaculture; Biological and medical sciences; Catfish; Catfishes; channel catfish; Continental surface waters; Copper; Copper - analysis; Copper - metabolism; Copper Sulfate - metabolism; copper sulphate; Culture; Exact sciences and technology; Fish and seafood industries; fish pond; Food industries; Fundamental and applied biological sciences. Psychology; Geologic Sediments - analysis; Natural water pollution; Pangasius hypophthalmus; Pollution; Pollution sources. Measurement results; Ponds; Sampling; sediment; Sediments; Sludge; Soil and sediments pollution; Toxic element; Toxicity; Vietnam; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; Water treatment and pollution
• ISSN: 1093-4529; 1532-4117
• DOI: 10.1080/10934529.2013.838869

Aquaculture of Pangasius hypophthalmus (striped catfish) in Vietnam reached 1.1 million tonnes in 2011 and catfish fillets are exported worldwide. The intensive cultures of catfish mainly in earth ponds have made it necessary to apply CuSO 4 and other chemicals to control external parasites and other pathogens. However, accumulation of Cu in aquaculture ponds may pose a hazard to growth of fish or to the aquatic environment. The aim of this study was to determine accumulation of Cu in sediment, water and fish in a catfish pond with a history of repeated treatment with CuSO 4 in the Mekong Delta, Vietnam. Copper concentrations in pond sediment were in the interval 21.3-45.7 mg kg −1 dw and did not exceed the Vietnamese values for soil to be used for agricultural production (70 mg kg −1 dw.). During three samplings the total mean concentration of Cu in pond water (4 μg L −1 ) did not exceed the LC 50 -value (70 μg L −1 ) for catfish and the mean dissolved concentration of Cu (0.986 μg L −1 ) did not seem to constitute a risk for the stability of the aquatic ecosystem. No significant variation in Cu concentrations between sampling sites in the pond and depth of sediment profile were determined. The accumulation of Cu in catfish was highest in the liver compared to the skin, gills and muscle tissue. With the current practice of removing pond sludge three to four times during a production cycle little if any Cu seems to accumulate in catfish ponds despite repeated anti-parasite treatments with CuSO 4 . Further studies are needed to assess the eco-toxicity and impact on agricultural production when pond sediment is discharged into aquatic recipients and used as soil fertilizer.