Transcript Biological Magnification

Biological Magnification
Biological Magnification
The problem occurs when a pollutant, such as
DDT or mercury, is present in the environment.
Chemically, these pollutants resemble essential
inorganic nutrients and are brought into the
producer's body and stored "by mistake".
The tendency for toxic substances/poisons to
increase in concentration in the tissues of
organisms at each higher feeding level in a food
chain.
Biological Magnification
Many toxic substances can’t
be broken down and
therefore are stored and
accumulated in living
tissues, especially fat.
Many toxic chemicals do not
cause a great deal of
harm when in low
amounts.
Biological Magnification
Because they are nonbiodegradable, they
remain in the
environment for long
periods of time.
As a result, the chances of
being consumed by
organisms and entering
the food chain increases.
Biological Magnification
Because toxins increase
at every level of the
food chain, organisms
that are at the top levels
of the food chain are
most greatly affected.
Therefore, organisms who
are affected the most by
biomagnification are
therefore 2nd and 3rd
level consumers
(including humans).
Biological Magnification
Examples.
DDT – used in pesticides in the mid 50’s
and 60’s
Heavy Metals – lead; formally used in
paints and metal processing, mercury;
used in gold mining
PCBs – Polychlorinated Biphenols; used in
fire retardants, plastics.
Summary:
In order for a pollutant to biomagnify, the
following conditions must be met:
1.The pollutant must be long-lived.
2.The pollutant must be concentrated by the
producers.
3.The pollutant must be fat-soluble.
Work
Read pg. 30-31 in Text
Do Q. #1-6, and choose one of 9, 10, or 11.
Read pg. 20 in pink booklet.
Do pg. 21