1. Bioaccumulation (or Biomagnification) in Food Chains

2. Some toxic chemicals in the environment are not even detectable with scientific equipment. Scientists could conclude that we are thus safe from these chemicals; but ecologists know better. The higher you go up in the food chain, the more you find these chemicals will accumulate. This process is called bioaccumulation (or biomagnification).

3. Compounds that bioaccumulate are fat soluble, meaning they are not excreted by the organism.
To reduce bioaccumulation humans should use water soluble compounds. Animals can excrete water soluble compounds out of their bodies.
The top carnivore always gets the most toxic chemicals.

4. Consider this food chain, showing the amount eaten in ONE DAY:
- a grasshopper eats 10 leaves of a leafy green vegetable or grain plant.
- a frog eats 10 grasshoppers
- a largemouth bass eats 2 frogs
Draw the food chain:

5. Consider this food chain, showing the amount eaten in ONE DAY:
- a grasshopper eats 10 leaves of a leafy green vegetable or grain plant.
- a frog eats 10 grasshoppers
- a largemouth bass eats 2 frogs
Draw the food chain:
leaf → grasshopper → frog → bass

6. 1. If there is one unit of a toxic chemical on each leaf, calculate how many units of toxic chemicals each organism gets, per day.
Grasshopper
Frog
Bass

7. 1. If there is one unit of a toxic chemical on each leaf, calculate how many units of toxic chemicals each organism gets, per day.
- Grasshopper = (1 unit/leaf x 10 leaves) = 10 units

8. 1. If there is one unit of a toxic chemical on each leaf, calculate how many units of toxic chemicals each organism gets, per day.
- Grasshopper = (1 unit/leaf x 10 leaves) = 10 units
- Frog = (10 units/grasshopper x 10 grasshoppers) = 100 units

9. 1. If there is one unit of a toxic chemical on each leaf, calculate how many units of toxic chemicals each organism gets, per day.
- Grasshopper = (1 unit/leaf x 10 leaves) = 10 units
- Frog = (10 units/grasshopper x 10 grasshoppers) = 100 units
- Bass = (100 units/frog x 2 frogs) = 200 units

10. Lets say that 1 unit of toxin = 1. 0 x 10-5g
Lets say that 1 unit of toxin = 1.0 x 10-5g. How many grams of toxin would each organism absorb each day?
- grasshopper
- frog
- bass

11. Lets say that 1 unit of toxin = 1. 0 x 10-5 g
Lets say that 1 unit of toxin = 1.0 x 10-5 g. How many grams of toxin would each organism absorb each day?
I unit of toxin = 1.0 x 10-5 g = g
grasshopper
frog
- bass

12. Lets say that 1 unit of toxin = 1. 0 x 10-5 g
Lets say that 1 unit of toxin = 1.0 x 10-5 g. How many grams of toxin would each organism absorb each day?
I unit of toxin = 1.0 x 10-5 g = g
grasshopper = 10 units/day x g/unit
= 1.0 x 10-4 g or g
frog
- bass

13. Lets say that 1 unit of toxin = 1. 0 x 10-5 g
Lets say that 1 unit of toxin = 1.0 x 10-5 g. How many grams of toxin would each organism absorb each day?
I unit of toxin = 1.0 x 10-5 g = g
grasshopper = 10 units/day x g/unit
= 1.0 x 10-4 g or g
frog = 100 units/day x g/unit = 1.0 x 10-3 or g
- bass

14. Lets say that 1 unit of toxin = 1. 0 x 10-5 g
Lets say that 1 unit of toxin = 1.0 x 10-5 g. How many grams of toxin would each organism absorb each day?
I unit of toxin = 1.0 x 10-5 g = g
grasshopper = 10 units/day x g/unit
= 1.0 x 10-4 g or g
frog = 100 units/day x g/unit = 1.0 x 10-3 g or g
bass = 200 units/day x g/unit
= 2.0 x 10-3 g or g

15. The problem is, the grasshoppers are not one day old
The problem is, the grasshoppers are not one day old. What if they have been eating this grass for over a year? (Lets say 200 days)
In one year grasshopper will eat:

16. The problem is, the grasshoppers are not one day old
The problem is, the grasshoppers are not one day old. What if they have been eating this grass for over a year? (Lets say 200 days)
In one year grasshopper will eat:
= 10 units/day x 200 days

17. The problem is, the grasshoppers are not one day old
The problem is, the grasshoppers are not one day old. What if they have been eating this grass for over a year? (Lets say 200 days)
In one year grasshopper will eat:
= 10 units/day x 200 days
= 2000 units

18. The problem is, the grasshoppers are not one day old
The problem is, the grasshoppers are not one day old. What if they have been eating this grass for over a year? (Lets say 200 days)
In one year grasshopper will eat:
= 10 units/day x 200 days
= 2000 units
= 2000 units x g
= 0.02 g

19. Now consider this aquatic food chain, also showing the amount eaten in one day:
- microscopic protozoa eat 50 strands of algae
- water fleas eat 100 protozoa
- krill eat 20 water fleas
- minnows eat 20 krill
salmon eat 10 minnows
Each strand of algae has 1 unit of poison
(which is harmless) (1 unit of poison = 1.0 x 10-8 g = g)

20. Draw the food chain:

21. algae → protozoa → water flea → krill → minnow → salmon
Draw the food chain:
algae → protozoa → water flea → krill → minnow → salmon

22. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
protozoa

23. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
protozoa
= (1 unit/algae x 50 algae/day x 100 days)
= 5000 units
= 5000 units x g
= 5 x 10-5 g or g

24. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
- water flea

25. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
- water flea
= (5000 units/protozoa x 100 protozoa/day x 100 days)
= units
= units x g
= 0.5 g

26. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
- krill

27. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
- krill
= ( units/water flea x 20 water fleas/day x 100 days)
= units (1.0 x 1011 units)
= 1.0 x 1011 units x g
=1000 g

28. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
- minnow

29. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
- minnow
= (1.0 x 1011 units/krill x 20 krill/day x 100 days) = (2.0 x 1014 units)
= 2.0 x 1014 units x g
= g

30. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
- salmon

31. 3. In about three months, lets say 100 days,
3. In about three months, lets say 100 days, how much does each organism have?
- salmon
= (2.0 x 1014 units/minnow x 10 minnows/day x 100 days) = units
(2.0 x 1017 units)
= 2.0 x 1017 units x g
= g

32. Can you explain why a bald eagle, if it eats mostly salmon, is doomed?

33. Can you explain why a bald eagle, if it eats mostly salmon, is doomed?
The Bald Eagle is the top carnivore and so it will be eating the animals that have accumulated the most toxins.

34. THE END!