Full text can be accessed at the following link http://link.springer.com/article/10.1007%2Fs10967-016-4756-yThe aim of the study was to determine element concentrations in lungfish and catfish from the river Mara with INAA and EDXF to assess the health impact of the North Mara gold mine (NMGM) in Tanzania. Twenty samples of each species were collected from two sites downstream and upstream along the river Mara in the vicinity of NMGM. The sampling sites were 70 km apart. Significantly higher concentrations (p ≤ 0.05) of Cr, Ni, Cu, and Se in one of the species taken downstream than in those taken upstream might indicate contamination of the river Mara caused by the mining activities.