This study examined some heavy metal concentrations in Rivers Meme and Ndian
of the Rio del Rey mangroves of Cameroon. This was necessitated by the use of
these rivers and some streams feeding them for livelihood, despite severe
anthropogenic influences. Forty water samples from varied depths were collected
in August 2009 and analysed for heavy metal accumulation. Six top soil samples
from the catchment areas were also analysed using standard methods. Very high
concentrations (16.19 to 20.50 mg/L) of Zn were obtained in some sites of River
Meme. Lead concentrations were significantly (P < 0.05) lower than the maximum
allowable concentrations for drinking water in both rivers. River Meme as opposed
to River Ndian had higher concentrations in streams than in wells. Insignificant
negative correlations existed between Cd and depth, depicting anthropogenic origin
dominance in River Meme as opposed to River Ndian. Principal component
analysis equally suggested this dominance. There was an insignificant (P>0.05)
positive correlation (r = 0.2575) between the cation exchange capacity and organic
matter of the soils in the Rio del Rey mangrove ecosystem. This makes the
mangrove ecosystem vulnerable to increase anthropogenic activities. Separate
policies adoptions for the management of both rivers are thus recommended.