Bioaccumulation
Science: KS3, topic 1.3.22
Bioaccumulation
In food webs, toxins can enter the system and build up in organisms. The build up of these toxins in organisms is called bioaccumulation.
Toxins in the environment
- Toxins are harmful chemicals that affect organisms in an ecosystem.
- Toxins are normally released because of human activity.
- Toxins can reach the environment by:
- Leaking from the chemical industry into land and water systems.
- Pollutants can also be released into the atmosphere.
Bioaccumulation
- In food webs, toxins can enter the system and build up in organisms.
- When these toxins build up in organisms, this is called bioaccumulation.
Bioaccumulation of pesticides
- Pesticides are used to kill pests and encourage more crop growth.
- Pesticides can be absorbed in the roots of plants.
- Pesticides then find their way into water systems.
Biomagnification
- Plants are producers.
- Plants are then eaten by primary consumers.
- Primary consumers are also eaten.
- The toxin is then passed from one trophic level to the next.
- The toxin accumulates in larger concentrations with the apex predator at the top of the food chain.
- This accumulation is called biomagnification.
Test yourself on Bioaccumulation
What absorbs pesticides so that they can enter a food chain?
Choose the true statement in each pair
Why does an apex predator usually have the highest toxin concentration in a food chain?