Title: Biological Magnification
1Biological Magnification
- Bill Addo, Haram Chang, Jay Chen, and Nabila
Akthar -
- Biology SB1
2What is Biological Magnification?
- Biological Magnification, also known as
Biomagnification, is the increase of substances
that occurs in food chains. -
- These substances are usually found in
contaminated environments. Substances, such as
pesticides and mercury, are absorbed by organisms
due to their environment or the food they
consume. The substance then accumulates inside
the cells. - When an organism higher in the food chain eats
multiple organisms below, each of them containing
some of the toxins, the toxins becomes more
concentrated in the higher food chain. Since this
continues throughout the food chain, organisms
higher in the food chain are the ones who will
obtain the most toxins. -
3Bioaccumulation
- Biological Magnification is often related with
Bioaccumulation, which is the increase of the
toxic substance in an organisms body. -
- These two terms are different
- Accumulation pertains to harmful substances in a
living organism's body and its effects. - Magnification deals with the substance being
passed along the food chain. - Bioaccumulation will cause a number of problems
within the body that contains it.
4How Biomagnification affects animals
- A common example of Biomagnification and
Bioaccumulation is the use of DDT in the 1960's
and 1970s. DDT, or dichlorodiphenyltrichloroethan
e, was overly used by humans as a pesticide. It
soon found its way into the environment. -
- DDT and other toxins eventually climbed up the
food chain, and affected the bald eagles, nearly
driving them to extinction. The DDT was absorbed
by organisms which the bald eagles hunted, such
as fish and carrion. Each bald eagle would eat
multiple numbers of these fish and carrion. -
- The DDT would accumulate inside each of the
eagles' bodies. The DDT would sterelize the birds
or cause them to make fragile eggs that would
break easily. This caused the birds population to
dwindle rapidly.
5Bald Eagle Population
Figure 1
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- http//www.fws.gov/midwest/eagle/population/chtofp
rs.html
6How DDT rises in a food chain
7Mercury
- Mercury is a natural substance, that is found in
very small quantities in the ocean. Human
interference with the environment, causes higher
levels of mercury in the ocean. -
- Algae, a producer, consistently absorbs the
mercury which is found in its environment.
However, it excretes it slowly. Often, zoo
plankton will consume the algae and the mercury
along with it. -
- The plankton is then consumed by small fish,
which is in turn consumed by larger fishes.
Eventually, the fishes end up on human dinner
tables. Humans, who consume fishes high in
mercury, will easily become ill from mercury
poisoning.
8Biological Magnification of Mercury
9The Biological Magnification of DDT in a marine
ecosystem.
10Toxins that Biomagnify
- DDT and Mercury are not the only toxin that
biomagnifies. Other examples include, but are not
limited to -
- PCB'S (polychlorinated biphenyls) used in
insulators, as a plasticizer, and fire retardant.
It biomagnifies, impairs reproduction and is
widespread in aquatic systems. -
- Cyanide is used in leaching gold and in fishing.
It is a dangerous toxin and is known to have
effects on coral reefs. -
- Selenium is concentrated by farming desert soils.
It is toxic and causes reproductive failures in
organisms. -
- Heavy metals such as mercury, copper, nickel,
zinc, and lead affect the nervous system and they
may affect reproduction.
11Toxins in Bodies of Water
Figure 2
http//www.epa.gov/med/grosseile_site/indicators/i
mages/ddtwalleye-fig7.gif
12Toxins in Bodies of Water
Figure 3
http//www.epa.gov/med/grosseile_site/indicators/e
rie_fish.html
13Toxins in Bodies of Water
Figure 4
http//www.epa.gov/med/grosseile_site/indicators/e
rie_fish.html
14More Biological Magnification
Figure 5
http//jan.ucc.nau.edu/doetqp-p/courses/env470/Le
ctures/lec39/Lec39.htm
15Why We Should Care
- Ironically, biomagnification and bioaccumulation
are caused by humans but also have a profound
impact on us. -
- It can lead to neurological effects such as
mental retardation in infants who contract it
through their mothers. -
- A weakened immune system is also the result of
biomagnification. -
- Some cancers are also linked through ingesting
these toxins. - It can also lead to organ failure in both animals
and humans. - Since some animals have weaker immune systems
then humans, they will die faster which can lead
to extinction if it continues.
16Prevention of Biomagnification
- In an attempt to eradicate biomagnification, the
U.S. and several countries worldwide have placed
a ban on the use of DDT. -
- People are trying to prevent harmful substances
such as oil and human waste from being dumped in
water. -
- Landfills are also trying to get rid of these
substances because they can seep into ground
water. -
17Special Thanks / Citations
- Information
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- http//en.wikipedia.org/wiki/Biomagnification
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- http//toxics.usgs.gov/definitions/biomagnificati
on.html -
- http//www.marietta.edu/biol/102/2bioma95.html
-
- http//www.epa.gov/med/grosseile_site/indicators/e
rie_fish.html -
- http//jan.ucc.nau.edu/doetqp-p/courses/env470/Le
ctures/lec39/Lec39.htm
18Special Thanks / Citations Continued
- Pictures
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- http//www.calgoldrush.com/graphics/images/contami
nation.gif -
- http//image.wistatutor.com/content/ecosystem/biol
ogical-magnification.jpeg - http//www.corg/html/stitch.php?s98965698293378i
d34347859802049fkeep. -
- http//www.fws.gov/midwest/eagle/population/chtofp
rs.html