what is biomagnification?
Biomagnification is the increase in the concentration of a substance with the increase in the trophic level. Lets take the example of DDT which have been applied on the farm lands. producers would accumulate certain amounts of DDT in them and then it would be passed on to the next trophic level. Concentration of DDT would increase with the trophic level. Producers having the minimum concentration while the tertiary consumers would have the highest concentration of DDT accumulation in them. This increase in concentration is termed biomagnification. Amount and concentration should not be confused with each other, amount might decrease in the trophic levels but the concentration increases.
Biomagnification, also known as bioamplification or biological magnification, is the increase in concentration of a substance that occurs in a food chain as a consequence of:
Persistence (can't be broken down by environmental processes)
Food chain energetics
Low (or nonexistent) rate of internal degradation/excretion of the substance (often due to water-insolubility)
The following is an example showing how biomagnification takes place in nature: An anchovy eats zooplankton that have tiny amounts of mercury that the zooplankton has picked up from the water throughout the anchovie's lifespan. A tuna eats many of these anchovies over its life, accumulating the mercury in each of those anchovies into its body. If the mercury stunts the growth of the anchovies, that tuna is required to eat more little fish to stay alive. Because there are more little fish being eaten, the mercury content is magnified.
Biomagnification is the accumulation of toxic substances over successive trophic levels in a food chain.
Hence, the last members of the food chain are more threatened to the toxicity of the substance and are therefore worst affected.
Eg. Biomagnification of DDT (non biodegradable) in sea birds
Biomagnification is the increase in concentration of a substance that occurs in a food chain as a consequence of:
- Persistence (can't be broken down by environmental processes)
- Food chain energetics
- Low (or nonexistent) rate of internal degradation/excretion of the substance (often due to water-insolubility)