The brown macroalgae Padina boergesenii as an indicator of heavy metal contamination in the zanzibar channel

A survey of the brown macroalgae Padina borgesenii was used to assess heavy metal contamination in the Zanzibar Channel. The algae were collected from 30 different stations in areas from Dar es Salaam to Bagamoyo on mainland Tanzania, and on the West Coast of Unguja Island, Zanzibar, It was found th at the concentrations of Mn, Zn, Cu and Fe were higher at the mainland stat ions than at the Zanzibar sites. All of the 5 most contaminated sites were located on the mainland side, two just north of Dar es Salaam city, two nea r the Kunduchi area, and one near the center of Bagamoyo town. Other elemen ts analyzed such as Cd, Cr, Ni, As, Mg, V, and S, fluctuated very little, a nd are thought to be equal to background values, Tissue contents of C, N an d P were also similar at the different sites, It is concluded that the brow n algae Padina can be a useful bio-indicator species for examining trends i n heavy metal contamination in this region.