Concentrations of mercury and cadmium in small pelagic fish from Lake Victoria, Kenya: The case of dagaa fishery

Abstract

Toxicity of heavy metals in organisms is partly because of tissues bioaccumulation. The objective of this study was to assess the concentrations of Mercury (Hg) and cadmium (Cd) in dagaa (silver cyprinid) from open and gulf waters and compare the concentrations to their maximum permissible limits under the regulations European Commission (EC) and World Health Organization (WHO). The study was undertaken during the dry season in December 2020. In this Study, both the dry and wet fish samples were collected from six dominant dagaa landing sites along Lake Victoria, Kenya namely Marenga, Uhanya, Litare, Sori, Asat and Bao. For both dry and wet samples, concentration of Cadmium was highest at Sori with an average of 0.028ppm and lowest at Asat (0.008ppm). Mercury was highest at Sori (0.339ppm) and lowest at Asat (0.093ppm). The study recommends continuous long-term monitoring of these metals in order to determine their sources, establish their actual concentration and thereafter come up with possible management actions.