Relationships Between Heavy Metals in Shrimp (Macro brachium felicinum) and Metal Levels in The Water Column and Sediments of Taylor Creek

Abstract

Heavy metals in the aquatic environment have to date originated fundamentally from naturally occurring geochemical resources. Nonetheless, this has been enhanced by anthropogenic activities resulting in pollution. Consequently, relationships and partitioning of heavy metals in the dissolved phase, suspended particulate matter (SPM), sediments and shrimp (Macrobrachium felicinum) were investigated in five selected sites along Taylor creek, southern Nigeria. The degree of relationships between the various metals was dissimilar in each of the investigated matrices. In the matrices studied, not several significant relationships (P<0.05) were obtained. Only Ni-Cd (r=0.95), Mn-Cd (r=0.63), Mn-Ni (r=0.64) were associated in the sediments and in SPM, Zn-Ni (r=0.72), which suggests that the sources were not common for both matrices. In the dissolved phase, no strong relationships (P<0.05) between the heavy metals were obvious. The best relationships were observed for Ni-Zn (r=0.72) and Cd-Pb (r=0.65). Partitioning coefficients (Kd) of heavy metals between dissolved phase and SPM were generally low, which is typical for fresh water ecosystems and fairly stable over the creek all through the seasons. Furthermore, the bio-concentration factors (BCFs) of Macrobrachium felicinum were low unlike those of other natural waters. Thus, the physical state of the aquatic ecosystem points to the fact that the heavy metals bio-accumulated by Macrobrachium felicinum give cause for concern when viewed in perspective to community health issues, as the communities along the creek depend directly on shrimps as a protein source.