First evaluation of iron and manganese concentrations in coastal aquaculture water in Giao Thuy district, Nam Dinh province

Aquaculture in the coastal zone has contributed significantly to economic development Giao Thuy district, Nam Dinh province. Therefore, water quality for aquaculture plays a vital role sustainable production. In this paper, iron (Fe) and manganese (Mn) concentrations of district were analyzed during rainy season (September 2017, August 2018) dry at low tide. The results showed that Fe concentration varied from 0.09 mg/L (at VT5) 2.42 VT4), averaging 1.12 ± 0.71 mg/L, which exceeded critical value national technical regulation on marine Vietnam (QCVN 10:2015/BTNMT) 1.5 times VT4) 3.0 VT1). Mn ranged 0.02 VT9) 0.10 VT1), 0.05 was lower than QCVN 10:2015/BTNMT. no apparent seasonal variation observed both concentrations. season, averaged 1.10 respectively, whereas they 1.15 season. monitoring polluted study area may affect productivity. helpful measures should be taken minimize pollution protect develop