BIOLOGICAL
MAGNIFICATION
By:
Matt and Kristi
What Is Biological Magnification?
• A trophic process in
which retained
substances(ex: pesticides
or heavy metals) become
more concentrated with
each link in the food
chain
• Similar to
bioaccumulants:
Toxic substance
(ex:heavy metals and
polychlorinated
biphenyls) that slowly
builds up in
concentration in living
organisms (including
bacteria, algae, fungi,
and plants).
Why Does It Happen?
• Because the biomass at any given trophic
level is produced from a much larger
biomass ingested from the level below, thus
meaning the top carnivores are most
affected
Examples
• Biological magnification of chlorinated
hydrocarbons, which includes many pesticides,
such as DDT and PCB (polychlorinated biphenyls)
• PCB in Great Lakes affect food chain with
affecting the herring gull eggs nearly 5,000 times
greater than in phytoplankton
• DDT (1950s) travels in water to places, and first
sign was when populations of pelicans, ospreys,
and eagles, and birds at the top of the food chain,
were decreasing
• Build up of DDT in the bird’s tissue interfered
with the deposition of calcium in their eggs, thus
making the eggs to weak to be incubated by the
parents, they just break