Bioaccumulation
Activity 1: Food chain
Construct a food chain using the organisms below. Use arrows to show energy
movement and label all tropic levels.
Grass
Aphid
Dragonfly
Sun
Bluebird
Sun
Uncle Bob takes pride in his garden. Everyday he spends the afternoon weeding,
watering and planting his special place. Unfortunately the bugs have enjoyed some of the
plants Uncle Bob has planted. To control the pests Uncle Bob went to the store and
bought Pesticide X, the strongest pesticide on the market. Pesticide X has a chemical that
is harmless to organisms in small quantities, but hazardous to organisms in large
quantities or concentrations. He uses the pesticide on the entire garden. This takes care
some of the bugs that are eating his garden but what else is it affecting?
1. Assuming that each higher level consumer consumes 10 times more toxins than
the level before, create a toxicity pyramid that shows the bioaccumulation that
occurs in the aforementioned food chain.
Example:
Fox eats voles and gains
500 ppm toxins
Vole eats caterpillars and
gains 50 ppm toxins
Caterpillars eat leaves
with 5ppm toxins
Tree leaves
with herbicide
applied
Aphids eat leaves from
garden and gain ________
ppm toxins
Pesticide X
applied to
garden at 10
ppm
2. According to your energy pyramid which of the organism is going to be affected
the most by the pesticide? Why?
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3. Why are the middle and lower levels of the food chain not affected as severely by
pesticide X?
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4. Write a brief email to Uncle Bob explaining the dangers of using pesticide X in
his garden. Make sure to explain bioaccumulation to get your point across.
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