Adverse Effects of Heavy Metals on Aquatic life

Abstract

The metals that are highly dense and toxic at low quantities are termed as heavy metals. These metals include Lead, Mercury, Cadmium, Copper, Zinc, Manganese, Nickel, Arsenic and Silver etc. Among these metals Arsenic, Cadmium, Chromium and Lead are considered most toxic to humans, animals and fish. Heavy metals enter the aquatic ecosystem through disposal of industrial, agricultural and municipal wastes and bioaccumulates in the food chain. Chromium is generally present in aquatic ecosystems between the range 1-10 µg/L which is highly toxic. Higher concentration of Chromium in aquatic ecosystem can result in accumulation in fish and have adverse effects on consumers’ health. Cadmium and Lead deposit on the gills of the fish and cause suffocation which may lead to death of the fish. Accumulation of Cadmium is generally associated with organ damage and anemia that results in death of the fish and its consumer. In the presence of Cadmium, the toxicity of Lead generally increases the toxicity drastically in Gambusia affinis.