1. Amy Collins, Aoife Rea, Stephen Ross, Sarah Wakeling and Rachel Nash
Food Pyramids
Presentation by:
Amy Collins, Aoife Rea, Stephen Ross, Sarah Wakeling and Rachel Nash

2. Errors and Misconceptions
Food Pyramids
Errors and Misconceptions

3. The following are NOT food pyramids:

4. A food pyramid IS: ...a way of showing the quantities
of energy available at
each stage in a food chain.

5. Pyramid of Numbers Shows the number of organisms in a food chain.
Each bar represents the number of individual organisms at each trophic level in the food chain.

6. Pyramid of Biomass
More accurate indication of how much energy is passed on at each trophic level.
It makes it easier to compare the food value of a small number of large organisms with a large number of small organisms.
Pyramids of biomass usually are a true pyramid shape.

7. How are food pyramids represented?
Tertiary consumers
Secondary consumers
Primary consumers
Primary producers

8. Each level or stage on a food pyramid is called a trophic level.
The terms ‘producer’ and ‘consumer’ are used to describe the different elements of a food pyramid and also a food chain.
Arrows are used to represent the energy transferred between each trophic level.

9. Primary producers are food producers (autotrophs) like green plants, that use the Sun’s energy to make food by photosynthesis. For example, leaves or grass. Primary consumers are animals that eat and gain their energy from primary producers (plants) – also known as herbivores. For example, caterpillar or rabbit.

10. Secondary consumers are animals that eat and gain energy from primary consumers (herbivores) – also known as carnivores. For example, small birds or a fox. Tertiary consumers are animals who gain energy from eating other animals further up the food pyramid. For example, an eagle may eat small rodents.

12. Toxins

13. Bioaccumulation One organism eats another.
However, it does not just get the tasty food that it has ate.
It also eats the poisonous toxins that are on its prey.

14. How it works
As it accumulates it affects the top of the food chain most.
Each animal will have more toxins in it than the one which it ate as it has eaten all the toxins within it.
The toxins originate in the sea

15. For example: An insect larva eats 1 toxin.
A small fish eat 10 insect larvae. Small fish has 10 toxins
A large fish eats 10 small fish so eats 100 toxins.
Cross- curricula with maths
You see the pattern- that’s just the start of the food chain

16. Imagine
When a Polar Bear eats a fish

17. Imagine...
A killer whale (orca)....

18. Imagine......
A person

19. Practical damage: Toxins have killed lots of killer whales
In humans scientists believe they can be a cause of miscarriages and downs syndrome