Temporal distribution of heavy metal concentrations in oysters Crassostrea rhizophorae from the central Venezuelan coast

•We report heavy metals in C. rhizophorae from the central Venezuelan coast.•We report annual variation of heavy metals in oysters of two estuaries.•The mean concentrations are higher in Buche estuary.•Our results show that for each metal there is a similar temporal variation pattern.•Cd, Cu, Ni and Mn values in Buche can be interpreted to be high on a global scale.