The Effects of Some Metals in Acidified Waters on Aquatic Organisms

Abstract

Mining metals or extraction of metals is an important process in our modern way of life. There are phases in the life of a mine that can discharge metals to estuaries, rivers, lakes and eventually oceans. These metals dissolve in water (very easily in acidified waters) and are either directly absorbed by fish and other aquatic organisms or indirectly absorbed from food chains. Small concentrations (levels) of metals can be toxic because metals undergo bio-concentration, which means that metal concentration in organisms gets higher than in water. The mobilization of metals in soluble forms from the soil to the aquatic ecosystem is an important consequence of acidification of lakes and streams. Heavy metals are generally less toxic at circum neutral pH but very toxic at low pH. This paper reviews the effects on these heavy metals in acidic (low pH) waters on fish and other aquatic organisms, and the consequences on human health as a result of humans being on top of the food chain. A lot of research has been done on the effect of heavy metals on human health and that’s not my reason for writing this paper, my aim has been to explore another path, which is how acidification of oceans, seas and rivers exacerbates the mobilization of metals into water bodies and how the acidic waters (low pH) have contributed to changing the metallic states into more lethal forms of metals - the metallic ions.