An Assessmental Study on the Determination of Heavy Metals in Sediment of Fish Farms in Bangladesh

The heavy metal pollution of aquatic ecosystems is often most obvious in sediments despite there is
scanty scientific works on revier sediemtn and fish in Bangladesh but unfortunately no work has yet
been published particularly on heavy metal contamination of fresh water fish farm sediment. Heavy
metals in mud surface sediments have been determined to assess environmental pollution of the
selected fish farms in Mymensingh, Bangladesh. Surface sediment samples (0-15 cm) from 20 ponds
of a fish farm were collected in February 2014 with a single core sampler and were analysed to
measure the concentrations (mg/Kg DW) of Zinc (Zn), Lead (Pb), Cadmium (Cd), Nickel (Ni) and
Chromium (Cr). The measured concentration of heavy metals in the present study was in order of, Zn
> Cr > Ni > Pb > Cd which are quite similar to the findings of other sediment of pond mud. The mean
concentrations of Zn, Pb, Cd, Cr, Ni observed in the present study were 208, 14.845, 0.009, 63.054
and 58.665 mg/kg respectively. The ranges of the measured concentrations (mg/kg) in the total
sediments were 11.5-18.5 for Pb, 0.007-0.011 for Cd, 53.5-77.3 for Cr, 50.8-66.4 for Ni and 100-250
for Zn. The concentrations of Zn and Ni in all sediment samples were above the US Environmental
Protection Agency’s (USEPA) guideline for severely polluted sediment and the concentration of Cr
falls under the moderately polluted range. The metal Pb and Cd concentrations are well below the
regulated level as per USEPA. Therefore, the study results revealed that the pond mud sediment
quality in Mymensingh region might be considered as highly and moderately polluted for Zn, Ni and Cr
respectively.