Abstract
Seven green algae species (Caulerpa spp., Cladophora spp., Dictospheria spp., Dictyosphaeria spp., Enteromorpha spp., Halimeda spp. and Ulva spp.) at the Sudanese Red Sea coast were examined for the total contents of some heavy metals. Samples were collected in triplicate along seven locations over 100 km, which includes the two main harbors of the Sudan (Port-Sudan and Sawakin). The levels of heavy metal uptake by algae were in the following descending order: Mn >> Cr approximate to Zn > Ni approximate to Cu > Pb >> Cd. Cluster analysis classified algae species, based on heavy metal contents, into two main clusters. One cluster included only Enteromorpha spp. while the other cluster included the rest of the species. Enteromorpha spp., Caulerpa spp. and Cladophora spp. recorded higher Mn uptake than other species while Enteromorpha spp. and Halimeda spp. recorded higher Ni uptake than other species. Suspicious manmade contribution by heavy metals could be reported since different levels of uptake of Mn, Cr, Zn and Cd were recorded in the similar species in some locations. The global comparative study showed that Ulva spp., Cladophora spp., Caulerpa spp., Halimeda spp. and Enteromorpha spp. have the higher affinity to heavy metal uptake than other species.