Biomagnification Definition

“Biomagnification or biological magnification is the process of accumulation of certain chemicals in living organisms to a concentration higher than that occurring in the inorganic, non-living environment.”

What is Biomagnification?

Biomagnification can be defined as the rise or increase in the contaminated substances caused by the intoxicating environment. The contaminants might be heavy metals such as mercury, arsenic, and pesticides such as polychlorinated biphenyls and DDT.

These substances are taken up by the organisms through the food they consume. When the organisms in the higher food chain feed on the organisms in the lower food chain containing these toxins, these toxins get accumulated in the higher organisms.

Lets us have a look at the causes and consequences of biomagnification.

Causes of Biomagnification

Following are the major causes of biomagnification:


The agricultural pesticides, insecticides, fertilizers and fungicides are very toxic and are released into the soil, rivers, lakes, and seas. These substances contain small amounts of heavy metals such as mercury, arsenic, copper, lead and cadmium. These cause health issues in aquatic organisms and humans.

Organic Contaminants

Manures and biosolids are processed industrially and contain contaminants like pharmaceuticals and personal care products. These substances have an adverse impact on the health of humans, animals, and wildlife.

Industrial Activities

The industries and factories release toxic substances that are released into the soil, lakes, oceans, and rivers. The gaseous emissions pollute the environment which enters into the food chain leading to biomagnification.

Mining Activities in the Ocean

Mining activities are carried out in the deep sea to extract metal like zinc, aluminium, cobalt, silver and gold. The mining process generates a large amount of selenium and sulphide, which deposits in water and destroys the oceans and coastal regions.

The level of toxicity is increased. These toxic substances are absorbed by the aquatic organisms higher in the food chain.

Also Read: Types of Pollution

Effects of Biomagnification

Following are the effects of biomagnification on living organisms and the environment:

Impact on Human Health

Biomagnification makes humans more prone to cancer, kidney problems, liver failure, birth defects, respiratory disorders, and heart diseases.

Effects on Reproduction and Development of Marine Creatures

The toxic chemicals accumulate in the important organs of aquatic organisms that affect their reproduction and development processes.

For eg., the shells of the eggs of the sea-birds are very thin that might get crushed by the birds themselves during incubation. The toxic chemicals, mercury and selenium destroy the reproductive organs of aquatic creatures.

Destruction of Coral Reefs

Cyanide that is used in leaching gold and fishing is the main cause of the destruction of coral reefs. Coral reefs are the dwelling and feeding grounds for many sea creatures. Their destruction affects the lives of many aquatic animals.

Disruption of Food Chain

The chemicals and toxins which are released into the water bodies disrupt the food chain. The small organisms absorb the toxins which are eaten up by larger animals. These toxins, thus, get accumulated in the higher level of organisms.

Also Read: Air, Water and Soil Pollution

Stay tuned with BYJU’S Biology for more information on biomagnification, causes, its effects and other related topics.


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