Spatial assessment of heavy metal concentrations in giant tiger shrimps (Penaeus monodon Fabricius, 1798) in Bodo Creek, Gokana LGA, Rivers State, Nigeria.
Eludoyin O.S., Balogun A.N. and Otali S.O.
This study assessed the heavy metals in shrimps and surface water in Bodo Creek, Gokana LGA, Rivers State, Nigeria. Five composite water samples were collected into the distilled plastic bottles from the upstream, midstream and downstream in relation to a point of discharge of pollutants. Similarly, giant shrimps were collected from the same locations. Laboratory analysis was carried out on Pb, Zn, Cd, Ni, and Fe on water and shrimp samples while pH, salinity, conductivity, temperature and dissolved oxygen (DO) of water samples were determined in situ. The means of heavy metals investigated in surface water and shrimps were explained using descriptive statistics while the significant relationships between the levels of heavy metal concentration of surface water and shrimps was determined by Spearman’s rank statistics. Findings reveal that the pH was 6.60 in the upstream, 6.10 in the midstream and 6.30 in the downstream. DO was highest at the midstream (3.10 mg/l) while the conductivity and salinity were highest in the upstream and least in the downstream. Mean Cd, Zn and Ni in the surface water were highest at the midstream with a value of 0.06 mg/l, 4.71 mg/l and 0.35 mg/l respectively while Fe and Pb were highest in the upstream with a value of 1.27 mg/l and 2.40 mg/l. However, mean Ni (3.78 mg/kg), Pb (1.48 mg/kg), Fe (1.48 mg/kg) and Zn (48.89 mg/kg) were highest in the shrimps found in the midstream while mean Cd (2.47 mg/kg) was highest in the downstream. The correlations between the heavy metals in the surface water and shrimps were significant at p<0.05. The study recommended that heavy metal concentrations in shrimp caught in Bodo Creek should be properly investigated before consumption to prevent incidences of human health complications.