First Determination of the Levels of Platinum Group Metals in Manta birostris (Manta Ray) Caught Along the Ghanaian Coastline

Tissues from Manta birostris caught by fishermen from Dixcove in the western part of Ghana were analyzed for their Platinum, palladium and rhodium concentrations (PGM). The use of chondrichthyan fish has permitted the study of trace levels of Platinum group metals (PGMs) which have travelled very far into the sea. The analysis showed that Ghana's coastline is fairly polluted with these platinum group metals (PGMs). PGM concentration in manta ray recorded a range of (0.15-0.85) mu g/g for Pt, (0.033-0.67) mu g/g for Pd and (0.007-0.145) mu g/g for Rh. Comparing these values to the UK dietary intake of 0.2 mu g/day for Pt and Rh and 1.0 mu g/day for Pd, its indicates that the values obtained from the analysis for Pt was above the required level. This is the first study to show the accumulation of PGM in chondrichthyan fish, although the sources of this pollution are not clear as manta birostris is migratory and therefore need to be investigated further. The presence of the PGM is very significant, since manta ray meat is consumed in Ghana. This may presents a health risk, due to a possible accumulation of PGMs in humans.