Transcript Barker Pyramids and Bioaccumulation Notes

Wednesday October 7th
In Notebook:
Identify: a primary
producer, primary
consumer, and
secondary consumer.
Today’s Learning Targets
Agenda:
1. Formative Assessment
2. Ecological Pyramids
3. Bioaccumulation/Biomagnification
Food Web vs. Food Chain
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Interpret these pyramids. Do you think these pyramids depend on each
other or are they independent?
What trends do we see in common for all these pyramids?
Biomass Pyramid
• The total mass of living matter
at each trophic level
• Why is there more biomass in
the lower trophic levels and
less biomass in the higher
trophic levels?
Energy Pyramid
• Shows trophic (feeding)
levels and energy available
to each level
– 10% energy gets passed to
each level
– 90% energy lost
(living/respiration)
Example:
Fill in the
levels of the
food chain
with the
energy passed
on.
10,000 J of energy
Example:
Fill in the
levels of the
food chain
with the
energy passed
on.
750,000 J of energy
While transferring energy what else can be
transferred??
...
Bioaccumulation vs.
Biomagnification
• Bioaccumulation = the accumulation of a
contaminant or toxin in or on an organism
from all sources (e.g., food, water, air)
– accumulate in living things and stored faster
than they are broken down or excreted
•
Biomagnification = the increase in
concentration of toxin as it passes through each
level of the food web
What affect does _____ have
on biomagnification?
Trophic Level
Life Span
Lactation
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Example:
•
•
DDT: a pesticide used for mosquito and pest control
•
In animals DDT is metabolized to DDE, which is stored in fatty
tissues and is insoluble in water.
•
Banned in U.S.A. in 1972
Damage from DDT: reproductive failure (birds have thinning
eggshells), immune system problems, nervous system damage,
death
Biomagnification of a DDE in Aquatic
Environment
Amount of DDE in Tissue
Level
Tertiary Consumer
3-76 µg/g ww
(fish eating birds)
Secondary Consumers
1-2 µg/g ww
(large fish)
Primary Consumers
0.2-1.2 µg/g ww
(small fish)
Primary Producers
(algae and aquatic plants)
0.04 µg/g ww
What does this mean for us?
Watch where your
food comes from!
Practice!
•
Use the following information to construct a food web in a meadow ecosystem:
•
Red foxes feed on raccoons, crayfishes, grasshoppers, red clover, meadow
voles, and gray squirrels
•
Red clover is eaten by grasshoppers, muskrats, red foxed, and meadow voles
•
Meadow voles, gray squirrels, and raccoons all eat parts of the white oak tree
•
Crayfishes feed on green algae and detritus, and they are eaten by muskrats
and red foxes.
•
Raccoons feed on muskrats, meadow voles, gray squirrels, and white oak trees.
•
Identify all of the herbivores, carnivores, omnivores, and detritivores in the food web.
•
Describe how the muskrats would be affected if disease kills the white oak trees.