What is bio magnification?? It is also known

as bioamplification or biological magnification, is the increase in concentration of a substance, such as the pesticide DDT, that occurs in a food chain as a consequence of:

Persistence ( Can't be broken down by environmental processes)

Food chain energetics Low rate of internal

degradation/excretion of the substance.

It also refers to the process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into rivers or lakes, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. The substances become concentrated in tissues or internal organs as they move up the chain.

Sometimes biomagnification is also used interchangeably with 'bioaccumulation,' an important distinction is drawn between the two, and with bioconcentration

Bioaccumulation occurs within a trophic level, and is the increase in concentration of a substance in certain tissues of organisms' bodies due to absorption from food and the environment.

Bioconcentration is defined as occurring when uptake from the water is greater than excretion .

Thus bioconcentration and bioaccumulation occur within an organism, and biomagnification occurs across trophic (food chain) levels.

Substances that biomagnify There are two There are two

main groups of main groups of substances that substances that biomagnify.  biomagnify. 

Both are lipophilic Both are lipophilic and not easily and not easily degraded.  degraded. 

These are These are 'persistent organic pollutants' or ' or POPs and Metals. and Metals.

Novel organic substances are not easily degraded because organisms lack previous exposure and have thus not evolved specific detoxification and excretion mechanisms, as there has been no selection pressure from them. These substances are consequently known as 'persistent organic pollutants' or POPs.

Persistent organic pollutants

Chemical structure of PCBs. The possible positions of chlorine atoms on the benzene rings are denoted by numbers assigned to the carbon atoms.

Chemical structure

Chemical structure

Metals Metals are not degradable because they Metals are not degradable because they

are elements. Organisms, particularly are elements. Organisms, particularly those subject to naturally high levels of those subject to naturally high levels of exposure to metals, have mechanisms exposure to metals, have mechanisms to sequester and excrete metals. to sequester and excrete metals. Problems arise when organisms are Problems arise when organisms are exposed to higher concentrations than exposed to higher concentrations than usual, which they cannot excrete usual, which they cannot excrete rapidly enough to prevent damage. rapidly enough to prevent damage. These metals are transferred in an These metals are transferred in an organic form.organic form.

Violet light from a helium cadmium metal vapor laser. The highly monochromatic color arises from the 441.563 nm transition line of cadmium.

Biomagnification has serious consequences for all species.

It is particularly dangerous for predator species especially if they are at the top of long food webs.

Predators are usually at or near the top of their food web. This puts them at risk because the degree of biomagnification is high by the time it reaches their trophic level.

Also, top predators usually consume large quantities of meat which has lots of fatty tissue and contaminants.

Polar bears, humans, eagles, and dolphins are examples of top predators, and all of these organisms are vulnerable to the effects of biomagnification.

PCBs cause liver cancer in humans.

Predators that consume large amounts of fish also have a high degree of risk because persistent hydrophobics are widely dispersed in aquatic food webs and are biomagnified in fish. Biomagnified

substances causes persistent hydrophobia.

Thank Thank you…you…