Levels of arsenic, mercury and selenium inClarias gariepinusfrom Sagua la Grande River, Cuba

Abstract

-This study first reports concentrations of arsenic (As) and selenium (Se) in fish tissue of Clarias gariepinus from Sagua la Grande River in the Villa Clara Province, Cuba. We also confirm the mercury (Hg) levels in these fish obtained previously. Individuals were captured in three areas near Sagua la Grande City, where this fish is a common source of food for the city inhabitants. Concentrations range of As, Hg and Se (in wet weight) were 0.01-0.11 mg.g x1 ; 0.03-0.24 mg.g x1 and 0.75-3.87 mg.g x1 , respectively. As and Se levels were positively correlated (n = 19, r = 0.673, P < 0.05). High levels of Se were found in fish tissue and in 31.6% (n = 6) of individuals captured exceeded the threshold value for Se toxicity, which means that Se is likely to produce adverse consequences on the fish themselves or on the wildlife organisms that eat them. As and Se concentrations were positively correlated with fish weight and length (P < 0.05). Fish from irrigation canal have higher Se concentrations than fish captured in the other two stations. However, no significant differences were found between Hg and As concentrations in fish at the three sampling stations. Finally, as the Se concentrations in C. gariepinus were abnormally high, we suggest the need for studies about Se sources in the zone, the effect of Se in fish and the intake associated with fish consumption.