Metal pollution in mangrove ecosystems in Dar es Salaam, Tanzania

Abstract

Environmental pollution through accumulation of metals in estuarine, coastal, and marine waters is a worldwide issue. Most contaminants originate inland and pass through these environments before dispersing into the ocean. The objectives of this study were to determine metal concentration levels of Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se and Zn in sediments, water, invertebrates and mangrove leaves collected from mangrove ecosystems along the coast of Dar es Salaam and Mbegani. Evidence of metal bioaccumulation of non-essential metals including Al, Cu, Fe, Mn and Zn was mostly found at sites located close to Dar es Salaam City centre, which decreased with increasing distance from the centre. Avicennia marina (mangrove leaves), Uca spp. and Terebralia palustris (invertebrates) were identified as suitable local species for monitoring metal concentrations in the region.